Positive Results from Mesoblast’s Phase 2 Trial of Cell Therapy in Diabetic Kidney Disease


Mesoblast Limited has announced results from its Phase 2 clinical Trial that evaluated their Mesenchymal Precursor Cell (MPC) product, known as MPC-300-IV, in patients who suffer from diabetic kidney disease. In short, their cell product was shown to be both safe and effective. The results of their trial were published in the peer-reviewed journal EBioMedicine.  Researchers from the University of Melbourne, Epworth Medical Centre and Monash Medical Centre in Australia participated in this study.

The paper describes a randomized, placebo-controlled, and dose-escalation study that administered to patients with type 2 diabetic nephropathy either a single intravenous infusion of MPC-300-IV or a placebo.

All patients suffered from moderate to severe renal impairment (stage 3b-4 chronic kidney disease for those who are interested).  All patients were taking standard pharmacological agents that are typically prescribed to patients with diabetic nephropathy.  Such drugs include angiotensin-converting enzyme inhibitors (e.g., lisinopril, captopril, ramipril, enalapril, fosinopril, ect.) or angiotensin II receptor blockers (e.g., irbesartan, telmisartan, losartan, valsartan, candesartan, etc.).  A total of 30 patients were randomized to receive either a single infusion of 150 million MPCs, or 300 million MPCs, or saline control in addition to maximal therapy.

Since this was a phase 2 clinical trial, the objectives of the study were to evaluate the safety of this treatment and to examine the efficacy of MPC-300-IV treatment on renal function.  For kidney function, a physiological parameter called the “glomerular filtration rate” or GFR is a crucial indicator of kidney health.  The GFR essentially indicates how well the individual functional units within the kidney, known as “nephrons,” are working.  The GFR indicates how well the blood is filtered by the kidneys, which is one way to measure remaining kidney function.  The decline or change in glomerular filtration rate (GFR) is thought to be an adequate indicator of kidney function, according to the 2012 joint workshop held by the United States Food and Drug Administration and the National Kidney Foundation.

nephronanatomy

Diabetic nephropathy is an important disease for global health, since it is the single leading cause of end-stage kidney disease.  Diabetic nephropathy accounts for almost half of all end-stage kidney disease cases in the United States and over 40% of new patients entering dialysis treatment.  For example, there are almost 2 million cases of moderate to severe diabetic nephropathy in 2013.

Diabetic nephropathy can even occur in patients whose diabetes is well controlled – those patients who manage to keep their blood glucose levels at a reasonable level.  In the case of diabetic nephropathy, chronic infiltration of the kidneys by inflammatory monocytes that secrete pro-inflammatory cytokines causes endothelial dysfunction and fibrosis in the kidney.

Staging of chronic kidney disease (CKD) is based on GFR levels.  GFR decline typically defines the progression to kidney failure (for example, stage 5, GFR<15ml/min/1.73m2).  The current standard of care (renin-angiotensin system inhibition with angiotensin converting enzyme inhibitors or angiotensin II receptor blockers) only delays the progression to kidney failure by 16-25%, which leaves a large residual risk for end-stage kidney disease.  For patients with end-stage kidney disease, the only treatment option is renal replacement (dialysis or kidney transplantation), which incurs high medical costs and substantial disruptions to a normal lifestyle.  Due to a severe shortage of kidneys, in 2012 approximately 92,000 persons in the United States died while on the transplant list.  For those on dialysis, the mortality rate is high with an approximately 40% fatality rate within two years.

The main results of this clinical trial were that the safety profile for MPC-300-IV treatment was similar to placebo.  There were no treatment-related adverse events.  Secondly, patients who received a single MPC infusion at either dose had improved renal function compared to placebo, as defined by preservation or improvement in GFR 12 weeks after treatment.  Third, the rate of decline in estimated GFR at 12 weeks was significantly reduced in those patients who received a single dose of 150 million MPCs relative to the placebo group (p=0.05).  Finally, there was a trend toward more pronounced treatment effects relative to placebo in a pre-specified subgroup of patients whose GFRs were lower than 30 ml/min/1.73m2 at baseline (p=0.07).  In other words, the worse the patients were at the start of the trial, the better they responded to the treatment.

The lead author of this publication, Dr David Packham, Associate Professor in the Department of Medicine at the University of Melbourne and Director of the Melbourne Renal Research Group, said: “The efficacy signal observed with respect to preservation or improvement in GFR is exciting, especially given that this trial was not powered to show statistical significance. Patients receiving a single infusion of MPC-300-IV showed no evidence of developing an immune response to the administered cells, suggesting that repeat administration is feasible and may in the longer term be able to halt or even reverse progressive chronic kidney disease. I hope that this very promising investigational therapy will be advanced to rigorous Phase 3 clinical trials to test this hypothesis as soon as possible.”

Patients who received s single IV infusion of MPC-300-IV cells showed no evidence of developing an immune response to the administered cells.  This suggests that repeated administration of MPCs is feasible and might even have the ability to halt, or even reverse progressive chronic kidney disease.

Packham and his colleagues hope that this cell-based therapy can be advanced to a rigorous Phase 3 clinical trial to further test this treatment.

Autologous Stem Cell Transplantation With Complete Ablation of Bone Marrow Delays Progression of Multiple Sclerosis in Small Phase 2 Trial


Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Around 2 million people, worldwide, suffer from MS. MS results from the patient’s immune system attacking the myelin sheath that surrounds nerve axons. These constant and relentless attacks upon the myelin sheath causes “demyelination,” resulting in loss of the sensory and motor function.

Treatment usually required the use of drugs that suppress the immune response. Some of these drugs work better than others, while other patients have forms of MS that do not respond to common MS treatment.

A new report published in the Lancet, has shown that chemotherapy followed by autologous hematopoietic stem cell transplantation (aHSCT) can completely halt clinical relapses of MS and prevent the development of new brain lesions in 23 of 24 MS patients. Patients who participated in this study experienced a prolonged period without the need for ongoing medication. Eight of the 23 patients had a sustained improvement in their disability 7.5 years after treatment. This is the first treatment to produce this level of disease control or neurological recovery from MS, but, unfortunately, treatment related risks limit its widespread use.

There are a few specialist centers that offer MS patients aHSCT. This treatment involves harvesting bone marrow stem cells from the patient, and then employing chemotherapy to suppress the patient’s immune system and essentially partially wipe it out. The isolated bone marrow is then reintroduced into the blood stream to “reset” the immune system and stop it attacking the body. However, a respectable percentage of MS patients relapse after these treatments. Therefore, these treatments must be refined and tweaked to improve their efficacy.

Drs Harold L Atkins and Mark S Freedman from The Ottawa Hospital and the University of Ottawa, Ottawa, Canada, respectively, and their colleagues, tested if complete destruction, rather than suppression, of the immune system during aHSCT could reduce the relapse rate in patients and increase the long-term rates of disease remission. They enrolled 24 patients aged 18-50 from three Canadian hospitals. All of these subjects had previously undergone standard immunosuppressive therapy, but these treatments had failed to control their MS. These patients all had poor prognosis and their disability ranged from moderate to requiring a walking aid to walk 100 meters (according to their Expanded Disability Status Scale or EDSS score).

Adkins and Freeman and their coworkers used a chemotherapy regimen of busulfan, cyclophosphamide and rabbit anti-thymocyte globulin to wipe out the patient’s bone marrow. Atkins explained that this treatment is “similar to that used in other trials, except our protocol uses stronger chemotherapy and removes immune cells from the stem cell graft product. The chemotherapy we use is very effective at crossing the blood-brain barrier and this could help eliminate the damaging immune cells from the central nervous system.” After being treated with chemotherapy regimen, the patients’ bone marrow was reconstituted with their previously isolated bone marrow.

This study’s primary outcome was activity-free survival at 3 years, using EDSS scores as the means of measuring MS progression, in addition to scanning for brain lesions, and assessing MS symptoms.

Of the 24 patients enrolled, one (4%) died from liver failure and sepsis caused by the chemotherapy. In the 23 surviving patients, prior to treatment, patients experienced 1.2 relapses per year on average, but after aHSCT, no relapses occurred during the follow-up period (between 4 and 13 years). These clinical outcomes were nicely complemented by an absence of newly detected brain lesions (as assessed by MRI images taken after the treatment). Initially, 24 MRI scans of the brains of all 24 subjects revealed 93 brain lesions, and after the treatment only one of the 327 scans showed a new lesion.

Despite the exciting success of this clinical trial, Freedman emphasized the need to interpret these results with caution: “The sample size of 24 patients is very small, and no control group was used for comparison with the treatment group. Larger clinical trials will be important to confirm these results. Since this is an aggressive treatment, the potential benefits should be weighed against the risks of serious complications associated with aHSCT, and this treatment should only be offered in specialist centers experienced both in multiple sclerosis treatment and stem cell therapy, or as part of a clinical trial. Future research will be directed at reducing the risks of this treatment as well as understanding which patients would best benefit from the treatment.”

Dr Jan Dörr, from the NeuroCure Clinical Research Center, Charité-Universitätsmedizin, Berlin, Germany, made this comment about this clinical trial: “These results are impressive and seem to outbalance any other available treatment for multiple sclerosis. This trial is the first to show complete suppression of any inflammatory disease activity in every patient for a long period…However, aHSCT has a poor safety profile, especially with regards to treatment-related mortality.”

He added: “So, will this study change our approach to treatment of multiple sclerosis? Probably not in the short-term, mainly because the mortality rate will still be considered unacceptably high. Over the longer term (and) in view of the increasing popularity of using early aggressive treatment, there may be support for considering aHSCT less as a rescue therapy and more as a general treatment option, provided the different protocols are harmonized and optimized, the tolerability and safety profile can be further improved, and prognostic markers become available to identify patients at risk of poor prognosis in whom a potentially more hazardous treatment might be justified.”

Bone Marrow Stem Cells and Tissue Engineering Give a Woman a New Smile


Massive injuries to the face can cause bone loss and “tooth avulsion.” Medically speaking, avulsion simply refers to the detachment of a body structure from its normal location by means of surgery or trauma. Dental implants and help with lost teeth, but if the facial bone has suffered so much loss that you cannot place implants in them, then you are out of luck. Dental prostheses can help, but these do not always fit very well.

Darnell Kaigler and his group at the University of Michigan Center for Oral Health wanted to help a 45-year-old woman who had lost seven teeth and a good portion of her upper jaw bone (maxilla) as a result of massive trauma to the face. This poor lady had some dentures that did not fit well and a mouth that did not work well.

Bone can be grown from stem cells, but getting those stem cells to survive and do what you want them to do is the challenge of regenerative medicine. Therefore, Dr. Kraigler and his group used a new technique to help this young lady, and their results are reported in the December 2014 issue of the journal Stem Cells Translational Medicine.

First, Kraigler and his co-workers extracted bone marrow stem cells from a bone marrow aspiration that was taken from the upper part of the hip bone (the posterior crest of the ilium for those who are interested).  They used a product called ixmyelocel-T from Aastrom Biosciences in Ann Arbor , MI. This product is a patient-specific, expanded multicellular therapy, cell-processing system that selectively expands mesenchymal cells, monocytes and alternatively activated macrophages, up to several hundred times more than the number found in the patient’s bone marrow, while retaining many of the hematopoietic cells collected from only a small sample (50ml) of the patient’s bone marrow. Thus, the healing cells from the bone marrow are grown and made healthy, after which the cells were bagged and frozen for later use.

ixmyelocel-T

Then the patient was readied for the procedure by having the gum tissue cut and lifted as a flap of tissue (under anesthesia, or course). Then four holes were drilled into the bone and setting screws were inserted. This is an important procedure, because implanted stem cells will not survive unless they have blood vessels that can bring them oxygen and nutrients. By drilling these holes, the tissue responds by making new blood vessels. To this exposed surface, the bone marrow-derived stem cells were applied with a tricalcium phosphate (TCP). TCP is a salt that will induce mesenchymal stem cells to form bone. Once the TCP + stem cell mixture was applied to the gum, a collagen membrane was placed over it, and the gum was then sewn shut with sutures.

Cell transplantation procedure. Front view (A) and top view (B) of the initial clinical presentation showing severe hard and soft tissue alveolar ridge defects of the upper jaw. Following elevation of a full-thickness gingival flap, the images show front view (C) and top view (D) of the severely deficient alveolar ridge, clinically measuring a width of only 2–4 mm. Front view (E) and top view (F) of the placement of “tenting” screws in preparation of the bony site to receive the graft. Placement of the β-tricalcium phosphate (seeded with the cells 30 minutes prior to placement at room temperature) into the defect (G), with additional application of the cell suspension following placement of the graft in the recipient site (H). Placement of a resorbable barrier membrane (I) to stabilize and contain the graft within the recipient site, and top view (J) of primary closure of the flap.
Cell transplantation procedure. Front view (A) and top view (B) of the initial clinical presentation showing severe hard and soft tissue alveolar ridge defects of the upper jaw. Following elevation of a full-thickness gingival flap, the images show front view (C) and top view (D) of the severely deficient alveolar ridge, clinically measuring a width of only 2–4 mm. Front view (E) and top view (F) of the placement of “tenting” screws in preparation of the bony site to receive the graft. Placement of the β-tricalcium phosphate (seeded with the cells 30 minutes prior to placement at room temperature) into the defect (G), with additional application of the cell suspension following placement of the graft in the recipient site (H). Placement of a resorbable barrier membrane (I) to stabilize and contain the graft within the recipient site, and top view (J) of primary closure of the flap.

Four months later, the patient underwent a cone-beam computed tomography (CBCT) scan. The bone regrowth can be seen in the figure below.

Cone-beam computed tomography (CBCT) scans. CBCT scans were used to render three-dimensional reconstructions of the anterior segment of the upper jaw and cross-sectional (top view) radiographic images to show volumetric changes of the upper jaw at three time points. (A, B): The initial clinical presentation shows 75% jawbone width deficiency. (C, D): Immediately following cell therapy grafting, there is full restoration of jawbone width. (E, F): Images show 25% resorption of graft at 4 months and overall net 80% regeneration of the original ridge-width deficiency.
Cone-beam computed tomography (CBCT) scans. CBCT scans were used to render three-dimensional reconstructions of the anterior segment of the upper jaw and cross-sectional (top view) radiographic images to show volumetric changes of the upper jaw at three time points. (A, B): The initial clinical presentation shows 75% jawbone width deficiency. (C, D): Immediately following cell therapy grafting, there is full restoration of jawbone width. (E, F): Images show 25% resorption of graft at 4 months and overall net 80% regeneration of the original ridge-width deficiency.

According to the paper, there was an “80% regeneration of the original jawbone.”

Into this newly regenerated bone, permanent dental implants were placed. The results are shown below.

Complete oral rehabilitation. Clinical presentation of the patient prior to initiation of treatment (A) and following completed oral reconstruction (B). (C): Periapical radiographs of oral implants showing osseointegration of implants and stable bone levels at the time of placement, 6 months following placement, and 6 months following functional restoration and biomechanical loading of implants with a dental prosthesis.
Complete oral rehabilitation. Clinical presentation of the patient prior to initiation of treatment (A) and following completed oral reconstruction (B). (C): Periapical radiographs of oral implants showing osseointegration of implants and stable bone levels at the time of placement, 6 months following placement, and 6 months following functional restoration and biomechanical loading of implants with a dental prosthesis.

Pardon me, but permit me an unprofessional moment when I say that this is really cool.  Of course, this patient will need to be observed over the next several years to determine the longevity of her bone regeneration, but the initial result is certainly something to be excited about.

Tricalcium phosphate or TCP has been used to induce the bone-making activities of mesenchymal stem cells.  It has also been used in several animal studies as a delivery vehicle for mesenchymal stem cells (for example, see Rai B, et al., Biomaterials 2010, 31:79607970; Krebsbach PH, et al., Transplantation 1997, 63:10591069; Zhou J, et al., Biomaterials 2010, 31:11711179).  TCP also seems to support stem cell proliferation, survival, and differentiation into bone.  Kresbach and others showed that TCP most consistently yielded bone formation when used as a delivery vehicle for mesenchymal stem cells compared to other biomaterials commonly used, such as gelatin sponges and demineralized bone matrix.  However, there are no studies that have ascertained how well stem cells attach to TCP, and this attachment is an important factor in determining how many stem cells reach the site of injury.  This study by Kaigler and his group (A. Rajan and others) showed that a 30-minute incubation of the cells with TCP gave sufficient attachment of the cells to the TCP for clinical use.  The efficiency of this incubation period was also not affected by the temperature.  

The other exciting features of this paper, is that most of the materials used in this study were commercially available.  The bone marrow stem cell isolation technique was pioneered by Dennis JE, and others in their 2007 article in the journal Stem Cells (25:25752582).  Effective commercialization of this technique has shown the efficacy of this procedure for clinical use.  This paper also shows the clinical feasibility of using TCP as a delivery vehicle for mesenchymal stem cell-based bone treatments.

In conclusion, I will quote the authors: “Cell survival and seeding efficiency in the context of tissue engineering and cell-therapy strategies are critical parameters for success that have not been rigorously examined in a clinical context. This study defined optimized conditions for these parameters using an autologous stem cell therapy to successfully treat a patient who had a debilitating craniofacial traumatic deficiency. To our knowledge, there have been no other clinical reports of cell therapy for the treatment of craniofacial trauma defects. This clinical report serves as solid foundation on which to develop more expanded studies using this approach for the treatment of larger numbers of patients with other debilitating conditions (e.g., congenital disorders) to further evaluate efficacy and feasibility.”

Mesenchymal Stem Cells Repair Cartilage Defects in Cynomolgus Monkeys


Repairing cartilage defects in the knee represents one of the primary goals of orthopedic regenerative medicine. Cartilage that covers the joints, otherwise known as articular cartilage, has a limited capacity for repair, which leads to further degeneration of the cartilage when it is damaged if it remains untreated. A number of surgical options for treating cartilage defects include microfracture, osteochondral grafting, and cell-based techniques such as autologous chondrocyte implantation (ACI). Each of these procedures have been used in clinical settings. Unfortunately cartilage injuries treated with microfracturing deteriorate with time, since the cartilage made by microfracturing has a high proportion of softer. less durable fibrocartilage.  Also osteochondral grafting suffers from a lack of lateral integration between host and donor cartilage.

Alternatively, tissue engineering has shown some promise when it comes to the healing of cartilage defects.  Mesenchymal stem cells (MSCs) are multipotent progenitor cells that have the ability to differentiate into several different cell lineages including cartilage-making chondrocytes.  MSCs have theoretical advantages over implanted chondrocytes when it come to healing potential.  MSCs have the ability to proliferate without losing their ability to differentiate into mature chondrocytes and produce collagen II and aggrecan. In the short-term, bone marrow-derived MSCs combined with scaffolds have been successful in cartilage repair using animal models such as rabbits (Dashtdar H, et al., J Orthop Res 2011; 29: 1336-42) sheep (Zscharnack M, et al., Am J Sports Med 2010; 38: 185769) and horses (Wilke MM, et al.,l J Orthop Res 2007; 25: 9132).  

In a recent study, Kazumasa Ogasawara and Yoshitaka Matsusue and their colleagues from Shiga University of Medical Science in Shiga, Japan, tested the ability of expanded bone marrow-derived MSCs that had been placed in a collagen scaffold to improve healing of cartilage defects in cynomolgus macaques (type of monkey).  Before this study, there were no previous studies using MSCs from primates for cartilage repair.  The monkey MSCs were shown to properly differentiate into fat, bone, or cartilage in culture, and then were transplanted into the injured cartilage in the cynomolgus macaque.  The efficacy of these cells were ascertained at 6, 12, and 24 weeks after transplantation.

In culture, the cynomolgus MSCs were able to differentiate into fat, bone, and cartilage.

Characteristics of bone marrow-derived MSCs. Panel (a) demonstrates the colony-forming properties of MSCs isolated from bone marrow of cynomolgus macaques using the present protocol (arrows). Bar: 1 cm. Panel (b) shows the adipogenetic properties of MSC-derived cells from staining of lipid droplets with oil red O (arrowheads). Bar: 20 μm. Panel (c) confirms the osteoblastic properties of MSC-derived cells with alkaline phosphatase staining (arrowheads). Bar: 30 μm. Panel (d) confirms the chondrogenetic properties from immunostaining of type-II collagen. Type-II collagen-positive matrix is stained red. Bar: 0.5 mm. Read More: http://informahealthcare.com/doi/full/10.3109/17453674.2014.958807.
Characteristics of bone marrow-derived MSCs. Panel (a) demonstrates the colony-forming properties of MSCs isolated from bone marrow of cynomolgus macaques using the present protocol (arrows). Bar: 1 cm. Panel (b) shows the adipogenetic properties of MSC-derived cells from staining of lipid droplets with oil red O (arrowheads). Bar: 20 μm. Panel (c) confirms the osteoblastic properties of MSC-derived cells with alkaline phosphatase staining (arrowheads). Bar: 30 μm. Panel (d) confirms the chondrogenetic properties from immunostaining of type-II collagen. Type-II collagen-positive matrix is stained red. Bar: 0.5 mm.
Read More: http://informahealthcare.com/doi/full/10.3109/17453674.2014.958807.

Upon transplantation into cartilage defects in the knee cartilage of cynomolgus monkeys, MSCs were compared with collagen gel devoid of MSCs.  The knees that received the transplantations did not show any signs of irritation, bone spurs or infection.  All of the animals had so-called “full-thickness cartilage defects,” and those in the non-treated group showed cartilage defects that did not change all that much.  The cartilage defects of the gel group had sharp edges at 6 weeks that were thinly covered with reparative tissue by 12 weeks, and at 24 weeks, the defect was covered with thick tissue, but the central region of the defects often remained uncovered, with a hollow-like deformity.  In the cartilage defects of those animals treated with MSCs plus the collagen gel, the sharp edges of the defects were visible at 6 weeks after the operation, but at 12 weeks, the defects were evenly covered with yellowish reparative tissue.  At 24 weeks, the defects were covered with watery hyaline cartilage-like tissue that was very similar to the neighboring naïve cartilage.

Macroscopic observations of the repaired defects in the 3 groups at 6 weeks (a, d, g), 12 weeks (b, e, h), and 24 weeks (c, f, i) after implantation. Scale bar: 5 mm. Arrow in (d): the sharp edge of the defect is visible at 6 weeks in the gel group. Arrow in (f): a hollow-like deformity remains in the central region of the defect, despite thick coverage by the reparative tissue. Arrow in (g): the sharp edge of the defect is also visible in the MSC group at 6 weeks. Read More: http://informahealthcare.com/doi/full/10.3109/17453674.2014.958807.
Macroscopic observations of the repaired defects in the 3 groups at 6 weeks (a, d, g), 12 weeks (b, e, h), and 24 weeks (c, f, i) after implantation. Scale bar: 5 mm. Arrow in (d): the sharp edge of the defect is visible at 6 weeks in the gel group. Arrow in (f): a hollow-like deformity remains in the central region of the defect, despite thick coverage by the reparative tissue. Arrow in (g): the sharp edge of the defect is also visible in the MSC group at 6 weeks.
Read More: http://informahealthcare.com/doi/full/10.3109/17453674.2014.958807.

When evaluated at the tissue level, Ogasawara and Matsusue and others used a stain called toluidine blue to visualize the amount of cartilage made by each treatment.  As you can see in the picture below, the non-treated group didn’t do so well.  In the full-thickness defect the region below the cartilage was filled with amorphous stuff 6 weeks after the procedure, and at 12 weeks, amorphous stuff faintly stained with toluidine blue, which reflects the conversion of the amorphous stuff into bone.  At 24 weeks, bone tissue reappeared below the cartilage zone, even though the bone did not look all that normal (no trabecular structure but woven bone-like structure).

In the gel group, cartilage-like tissue is seen at 6 weeks, and at 12 weeks, the faintly stained layer covered the cartilage defect. At 24 weeks, the defect was covered with the cartilage-like stuff, even though the central region had only a little cartilage, as ascertained by toluidine blue staining.  The bone underneath the cartilage looked crummy and there was excessive growth of cartilage into the region underneath the cartilage layer.

In the MSC group, the bone underneath the cartilage healed normally, and at 12 weeks, the boundary between the articular cartilage and the bone layer beneath it had reappeared.  At 24 weeks, the thickness of the toluidine blue-stained cartilage layer was comparable to that of the neighboring naïve cartilage.

Even though the gel group showed most cartilage-rich tissue covering the defect, this was due to the formation of excessive cartilage extruding through the abnormal lower bone layer.  Despite the lower amount of new cartilage produced, the MSC group showed better-quality cartilage with a regular surface, seamless integration with neighboring naïve cartilage, and reconstruction of the bone underneath the cartilage layer.

Histological findings after toluidine blue staining in the 3 groups at 6 weeks (a, d, g), 12 weeks (b, e, h), and 24 weeks (c, f, i) after implantation. Scale bar: 2 mm. Dotted line in (a): amorphous reparative tissue filling the subchondral region. Arrowheads in (b): faint toluidine blue staining that reflects involvement of endochondral ossification. Arrowhead in (c): toluidine blue-negative reparative tissue covering the defect. Dotted line in (c): reconstructed subchondral bone consisting of woven bone-like structure. Arrowhead in (d): toluidine blue-positive cartilaginous tissue. Arrowhead in (e): thin faintly toluidine blue-positive layer covering the defect. Arrowhead in (f): the unstained central region of the cartilaginous layer covering the defect. Arrow in (f): excessive cartilage extruding through the deficient tidemark. Dotted line in (g): woven bone-like subchondral bone already re-appearing at 6 weeks. Arrowhead in (h): reconstructed tidemark distinctly discriminating the articular cartilage from the subchondral bone.
Histological findings after toluidine blue staining in the 3 groups at 6 weeks (a, d, g), 12 weeks (b, e, h), and 24 weeks (c, f, i) after implantation. Scale bar: 2 mm. Dotted line in (a): amorphous reparative tissue filling the subchondral region. Arrowheads in (b): faint toluidine blue staining that reflects involvement of endochondral ossification. Arrowhead in (c): toluidine blue-negative reparative tissue covering the defect. Dotted line in (c): reconstructed subchondral bone consisting of woven bone-like structure. Arrowhead in (d): toluidine blue-positive cartilaginous tissue. Arrowhead in (e): thin faintly toluidine blue-positive layer covering the defect. Arrowhead in (f): the unstained central region of the cartilaginous layer covering the defect. Arrow in (f): excessive cartilage extruding through the deficient tidemark. Dotted line in (g): woven bone-like subchondral bone already re-appearing at 6 weeks. Arrowhead in (h): reconstructed tidemark distinctly discriminating the articular cartilage from the subchondral bone.

This protocol has been nicely optimized by Ogasawara and Matsusue and their research team.  From these data, they conclude:  “Application in larger defects is certainly in line with future clinical use. If MSCs—under optimized conditions—turn out to be superior to chondrocyte implantation in experimental cartilage repair, the procedure should be introduced to clinical practice after well-controlled randomized clinical trials.”  Hopefully, clinical trials will commence before long.  This procedure uses a patient’s own MSCs, and if such a procedure could reduce or delay the number of knee replacements, then it would surely be a godsend to clinicians and patients alike.

Human Menstrual Blood Stem Cells Treat Premature Ovarian Failure in Mice


Premature ovarian failure (POF) or primary ovarian insufficiency is a condition characterized by loss of normal ovarian function before age 40. POF causes low levels of the hormone estrogen and irregular ovulation (release of eggs). POF causes infertility.

Some medical professional call POF premature menopause, even though these two conditions are not exactly the same. Women with POF may have irregular or occasional menstrual cycles for years and may even become pregnant. However, women with premature menopause cease having periods and can’t become pregnant.

The symptoms of POF are similar to those of menopause: irregular or skipped periods (amenorrhea), which may be present for years or may develop after a pregnancy or after stopping birth control pills; hot flashes, night sweats, vaginal dryness, irritability or difficulty concentrating, and decreased sexual desire.

In women with POF, infertility is very hard to treat, but restoring estrogen levels can avert many of the complications.

There are several causes of POF. Particular chromosomal defects such as Turner’s syndrome, in which a woman has only one X chromosome instead of the usual two, and fragile X syndrome, a major cause of intellectual disability can cause POF. Likewise, exposure to various toxins can also cause POF. Chemotherapy and radiation therapy are probably the most common causes of toxin-induced POF. Other toxins such as cigarette smoke, industrial chemicals, pesticides and viruses may also hasten POF. If the immune system mounts an immune response to ovarian tissue (autoimmune disease), then it might produce antibodies against the woman’s own ovarian tissue. Such antibodies will harm the egg-containing follicles and damage the egg. What triggers the immune response is unclear, but exposure to certain viruses is one possibility. Also various sundry unknown factors may also contribute to it.

There are no treatments for POF that restore the ovaries. For this reason a recent paper in the journal Stem Cells and Development represents a great advance in POF treatment.

Te Liu from the Shanghai Institute of Chinese Medicine and colleagues have used stem cells isolated from human menstrual blood to treat toxin-induced POF in mice.

Human endometrial stem cells exhibit stem cell properties in culture. These human endometrial stem cells are easily isolated from human menstrual blood. Other laboratories have even used them to treat heart conditions in clinical trials.

In this present study, Liu and colleagues treated female mice with the anti-cancer/anti-organ rejection drug cyclophosphamide. This drug pushed the mice into POF. Then one group of mice had human menstrual stem cells injected into their ovaries whereas another group received an injection of phosphate-buffered saline.

After 14 days, ovaries from those mice injected with human menstrual stem cells expressed higher levels of ovarian-specific proteins. Also, the blood levels of estrogen of the stem cell-injected mice were also higher. Postmortem examination also showed that the average ovarian weight of the stem cell-injected mice was much higher, as was the number of normal follicles. Follicles contain eggs surrounded with follicle cells and their absence is indicative of an ovary from a woman who is in menopause. That fact that the stem cell-treated POF mice had normal follicles and more of them suggests that the injected stem cells beefed up the supply of existing eggs and helped them survive and flourish.

These results suggest that these human menstrual stem cells, which are derived from the endometrium, can survive when introduced into a living organism and promote the regeneration of ovaries. There is no evidence that these cells differentiate into eggs, but instead they probably create an environment where the existing moribund eggs are rejuvenated and revitalized. This treatment for POF might be a viable option for human patients; all without destroying human embryos.

Adult Stem Cells Used for Spinal Disc Repair


The Australian regenerative medicine company Mesoblast Limited announced the results of their 12-month clinical trial that examined the use of their “off-the-shelf” product to treat patients with disc-related low back pain.

This phase 2 clinical trial enrolled 100 patients with chronic moderate to severe “discogenic low back pain” and tested the ability of “mesenchymal precursor cells” to shore up degenerating intervertebral discs.

Intervertebral discs

Intervertebral discs sit between each vertebra and act as shock absorbers. Each disc consist of an outer layer called the “annulus fibrosus.” The annulus fibrosus consists of several layers of fibrocartilage. The annulus fibrosus surrounds an inner layer called the nucleus pulposus, which contains loose fibers suspended in a mucoprotein gel with the consistency of jelly. This jelly-like center distributes pressure evenly across the disc. These discs absorb the impact of the body’s daily activities and keep the two vertebrae separated. The development of a prolapsed disc results when the jelly in the nucleus pulposus is forced out of the doughnut/disc, which may put pressure on the nerve located near the disc.

Intervertebral structure

More than six million people in the United States alone deal with chronic back pain that has persisted for at least three months, and 3.5 million people are affected by moderate or severe degenerative intervertebral disc disease.

In this clinical trial, Mesoblast Limited injected their mesenchymal precursor cells (MPCs) into the degenerating intervertebral discs of patients suffering from moderate to severe back pain. When compared with a control group, patients who received the MPC injections used less pain killers, went through fewer surgeries and non-surgical interventions, and had greater disc stability as ascertained by X-rays. MPC injections also were well tolerated and produced few side effects.

This phase 2 clinical trial extends earlier observations by Mesoblast Limited on laboratory animals. In preclinical trials, purified MPCs increased the quality of the jelly content of the nucleus pulposus and improved disc structure in sheep.

This present study enrolled 100 patients at 13 different sites across Australia and the United States with early disc degeneration and randomly assigned the subjects to one of four groups: 1) those who received saline injections; 2) those who received hyaluronic acid injections; 3) those who received low-dose MPCs in hyaluronic acid; and 4) those who received high-dose injections of MPCs in hyaluronic acid.

All patients received their injections in an outpatient procedure, and are being evaluated for safety and efficacy to evaluate long-term treatment effects.

At 12 months, the key findings were improvement in chronic low back pain, function, and disc stability. Also, no safety concerns emerged as a result of the treatment.

As this trial proceeds, more data should be forthcoming.

A Patient’s Own Bone Marrow Stem Cells Defeat Drug-Resistant Tuberculosis


People infected with multidrug-resistant forms of tuberculosis could, potentially, be treated with stem cells from their own bone marrow. Even though this treatment is in the early stage of its development, the results of an early-stage trial of the technique show immense promise.

British and Swedish scientists have tested this procedure, which could introduce a new treatment strategy for the estimated 450,000 people worldwide who have multi drug-resistant (MDR) or extensively drug-resistant (XDR) TB.

This study, which was published in the medical journal, The Lancet, showed that over half of 30 drug-resistant TB patients treated with a transfusion of their own bone marrow stem cells were cured of the disease after six months.

“The results … show that the current challenges and difficulties of treating MDR-TB are not insurmountable, and they bring a unique opportunity with a fresh solution to treat hundreds of thousands of people who die unnecessarily,” said TB expert Alimuddin Zumla at University College London, who co-led the study.

TB initially infects the lungs but can rapidly spread from one person to another through coughing and sneezing. Despite its modern-day resurgence, TB is often regarded as a disease of the past. However, recently, drug-resistant strains of Mycobacterium tuberculosis, the microorganism that causes TB, have spread globally, rendering standard anti-TB drug treatments obsolete.

The World Health Organisation (WHO) estimates that in Eastern Europe, Asia and South Africa 450,000 people have MDR-TB, and close to half of these cases will fail to respond to existing treatments.

Mycobacterium tuberculosis, otherwise known as the “tubercle bacillus, trigger a characteristic inflammatory response (granulomatous response) in the surrounding lung tissue that elicits tissue damage (caseation necrosis).

Bone-marrow stem cells are known to migrate to areas of lung injury and inflammation. Upon arrival, they initiate the repair of damaged tissues. Since bone marrow stem cells also they also modify the body’s immune response, they can augment the clearance of tubercle bacilli from the body. Therefore, Zumla and his colleague, Markus Maeurer from Stockholm’s Karolinska University Hospital, wanted to test bone marrow stem cell infusions in patients with MDR-TB.

In a phase 1 trial, 30 patients with either MDR or XDR TB aged between 21 and 65 who were receiving standard TB antibiotic treatment were also given an infusion of around 10 million of their own bone marrow-derived stem cells.

The cells were obtained from the patient’s own bone marrow by means of a bone marrow aspiration, and then grown into large numbers in the laboratory before being re-transfused into the same patient.

During six months of follow-up, Zumla and his team found that the infusion treatment was generally safe and well tolerated, and no serious side effects were observed. The most common non-serious side effects were high cholesterol levels, nausea, low white blood cell counts and diarrhea.

Although a phase 1 trial is primarily designed only to test a treatment’s safety, the scientists said further analyses of the results showed that 16 patients treated with stem cells were deemed cured at 18 months compared with only five of 30 TB patients not treated with their own stem cells.

Maeurer stressed that further trials with more patients and longer follow-up were needed to better establish how safe and effective the stem cell treatment was.

But if future tests were successful, he said, this could become a viable extra new treatment for patients with MDR-TB who do not respond to conventional drug treatment or for those patients with severe lung damage.

Stem Cells from Bone Marrow Help Heal Hard-to-Heal Bone Fractures


A new study that has appeared in the journal STEM CELLS Translational Medicine demonstrates the potential of a subset of stem cells called CD34+ in treating stubborn bone fractures that prove hard to heal.

The body has mechanisms for the repair of broken bones. Consequently, most patients recover from broken bones with little or no complication. However, up to 10 percent of all fracture patients experience fractures that refuse to heal. Such heard to heal fractures can lead to several debilitating side effects that include infection and bone loss, and the healing of hard to heal fractures often requires extensive treatment that includes multiple operations and prolonged hospitalization as well as long-term disability.

Regenerating broken bones with stem cells could offer an answer to this medical conundrum. Adult human peripheral blood CD34+ cells have been shown to contain a robust population of endothelial progenitor cells (EPCs) and hematopoietic stem cells, which give rise to all types of blood cells. These two types of stem cells might be good candidates for this therapy.

However, while other types of stem cells have been tested for their bone regeneration potential, the ability of CD34+ stem cells to facilitate bone healing has not been examined; that is until now. A phase I/II clinical study that evaluated the capacity of CD34+ to stimulate bone regeneration was published in the current edition of STEM CELLS Translational Medicine. This study was conducted by researchers at Kobe University Graduate School of Medicine, led by Tomoyuki Matsumoto, M.D., and Ryosuke Kuroda, M.D., members of the university’s department of orthopedic surgery and its Institute of Biomedical Research and Innovation (IBRI).

Matsumoto’s and Kuroda’s study was designed to evaluate the safety, feasibility and efficacy of autologous and G-CSF-mobilized CD34+cells in patients with non-healing leg bone breaks that had not healed in nine months. Seven patients were treated with CD34+ stem cells after receiving bone grafts.

In case you were wondering, G-CSF is a drug that releases stem cells from the bone marrow into the blood. It is given by injection or intravenously, and works rather well to mobilize bone marrow stem cells into the peripheral circulation.  It has clinical uses for patients recovering from chemotherapy.  Filgrastim (Neupogen) and PEG-filgrastim (Neulasta) are two commercially-available forms of recombinant G-CSF.

“Bone union was successfully achieved in every case, confirmed as early as 16.4 weeks on average after treatment,” Dr. Kuroda said.

Dr. Matsumoto added, “Neither deaths nor life-threatening adverse events were observed during the one year follow-up after the cell therapy. These results suggest feasibility, safety and potential effectiveness of CD34+ cell therapy in patients with nonunion.”

Atsuhiko Kawamoto, MD, Ph.D., a collaborator in IBRI, said, “Our team has been conducting translational research of CD34+ cell-based vascular regeneration therapy mainly in cardiovascular diseases. This promising outcome in bone fracture opens a new gate of the bone marrow-derived stem cell application to other fields of medicine.”

Although the study documents a relatively small number of patients, the results suggest the feasibility, safety and potential effectiveness of CD34+ cell therapy in patients with non-healing breaks,” said Anthony Atala, M.D., editor of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine.

Wound Healing Therapy That Combines Gene and Stem Cell Therapy


Researchers from Johns Hopkins University have examined wound healing in older mice and discovered that increasing blood flow to the wound can increase the rate of wound healing. Increasing blood flow to the wound requires a combination of gene therapy and the same stem cells the body already uses to heal itself.

John W. Harmon is professor of surgery at Johns Hopkins School of Medicine, and in a presentation to the American College of Surgeons’ Surgical Club, made the case that harnessing the power of bone marrow stem cells can increase the rate at which older people heal.

As we age, our wounds do not heal as fast. However, Harmon thinks that harnessing the power of bone marrow stem cells can remedy this disparity in healing rates.

To heal burns or other wounds, stem cells from the one marrow rush into action and home to the wound where they can differentiate into blood vessels, skin, and other reparative tissues. Stem cell homing is mediated by a protein called Hypoxia-Inducible-Factor-1 (HIF-1). According to Harmon, in older patients, few of these stem cells are released from the bone marrow and there is a deficiency of HIF-1. HIF-1 was actually discovered about 15 years ago by one of Harmon’s collaborators, a Johns Hopkins scientist named Gregg J. Semenza.

HIF-1
HIF-1

Harmon’s first strategy was to boost HIF-1 levels by means of gene therapy. This simply consisted of injecting the rodents with a copy of the HIF-1 gene that yielded higher levels of HIF-1 expression.

Even though higher levels of HIF-1 improved wound healing rates, burns were another story. To accelerate burn healing, Harmon and his co-workers used bone marrow stem cells from younger mice combined with the increased levels of HIF-1. This combination of HIF-1 and bone marrow stem cells from younger mice led to accelerated healing of burns so that after 17 days, almost all the mice had completely healed burns. These animals that healed so fast showed better blood flow to the wound and more blood vessels supplying the wound.

Harmon said that while this strategy is promising, he think that a procedure that uses a patient’s own bone marrow cells would work better since such cells would have a much lower chance of being rejected by the patient’s immune system. In the meantime, HIF-1 gene therapy has been successfully used in humans with a sudden lack of blood flow to a limb (see Rajagopalan S., et al., Circulation. 2007 Mar 13;115(10):1234-43). Harmon postulated that “it’s not a stretch of the imagination to think this could someday be used in elderly people with burns or other difficult wounds.”

Radio Interview About my New Book


I was interviewed by the campus radio station (89.3 The Message) about my recently published book, The Stem Cell Epistles,

Stem Cell Epistles

It has been archived here. Enjoy.

Stem Cell Therapy Repairs Brain Damage Hours After Stroke Occurs


According to the Center for Disease Control, stroke is a leading cause of death in the United States. Fortunately stroke has been the subject of significant research efforts, but unfortunately, developing treatments that ensure complete recovery for stroke patients is extremely challenging. The challenge increase when more than a few hours have passed between onset of the stroke and administration of treatment.

Thus a new study released in STEM CELLS Translational Medicine has generated more than a little excitement. This study indicates that indicates that endothelial precursor cells (EPCs), which are found in the bone marrow, umbilical cord blood, and rarely in peripheral blood, can make a significant difference for these patients’ recovery. The contribution of EPCs even extends to the later stages of stroke. In animal studies, EPC implantation into the brain after a stroke minimized the initial brain injury and helped repair the stroke damage.

“Previous studies indicated that stem/progenitor cells derived from human umbilical cord blood (hUCB) improved functional recovery in stroke models,” noted Branislava Janic, Ph.D., a member of Henry Ford Health System’s Cellular and Molecular Imaging Laboratory in Detroit and lead author of the study. “We wanted to examine the effect of hUCB-derived AC133+ endothelial progenitor cells (EPCs) on stroke development and resolution in rats.”

Dr. Janic and his team injected EPCs into the brains of rats that had suffered strokes. When they later examined the animals using MRI, they found that the transplanted EPCs had selectively migrated to the injured area, stopped the tissue damage from spreading, initiated regeneration, and affected the time course for stroke resolution. The lesion size in the brain was significantly decreased at a dose of 10 million cells, if the cells were given as early as seven days after the onset of the stroke.

“This led us to conclude that cord blood-derived EPCs can significantly contribute to developing more effective treatments that allow broader time period for intervention, minimize the initial brain injury and help repair the damage in later post-stroke phases,” Dr. Janic said.

“The early signs of stroke are often unrecognized, and many patients cannot take advantage of clot-busting treatments within the required few hours after stroke onset,” said Anthony Atala, M.D., editor of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine. “In this animal study, a combination of stem cells shows promise for healing stroke damage when administered 24 hours after the stroke.”

Urinary Stem Cells and Their Therapeutic Potential


Yuanyuan Zhang, assistant professor of regenerative medicine at Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine, has extended earlier work on stem cells from urine that suggests that these cells might be more therapeutically useful than previously thought.

These urinary stem cells can be isolated from a patient’s urine sample, and they can be induced, in the laboratory, to form bladder-type cells; smooth muscle and urothelial (bladder-lining) cells. Such stem cells could certainly be used to treat urinary tract problems, even though a good deal more work is required to confirm that they can do just that.

Nevertheless, Zhang and his co-workers have discovered that these urinary tract stem cells are much more plastic than previously thought. In the laboratory, Zhang and others have managed to differentiate urinary tract stem cells into bone, cartilage, fat, skeletal muscle, nerve, and endothelial cells (the cells that line blood vessels). This suggests that urine-derived stem cells could be used in a variety of therapies.

USCs undergo multipotential differentiation in vitro. (a-c) endothelial differentiation of USCs. USCs (p3) were induced to endothelial lineage by culture in EBM-2 medium containing VEGF 50 ng/ml for 14 days. (a) In vitro vessel formation. Endothelial differentiated USCs were cultured on Matrigel for 18h to form branched networks (angiogenesis) and tubular structures. Scale bar = 100μm. (b) Expression analysis of endothelial-specific transcripts by RT-PCR. (c) Immunofluorescence staining using endothelial-specific markers revealed enhanced staining of the markers with differentiation (middle row) compared to the non-treated control (top row). Scale bar = 50μm.
USCs undergo multipotential differentiation in vitro. (a-c) endothelial differentiation of
USCs. USCs (p3) were induced to endothelial lineage by culture in EBM-2 medium containing
VEGF 50 ng/ml for 14 days. (a) In vitro vessel formation. Endothelial differentiated USCs were
cultured on Matrigel for 18h to form branched networks (angiogenesis) and tubular structures. Scale
bar = 100μm. (b) Expression analysis of endothelial-specific transcripts by RT-PCR. (c)
Immunofluorescence staining using endothelial-specific markers revealed enhanced staining of the
markers with differentiation (middle row) compared to the non-treated control (top row). Scale bar =
50μm.

Zhang said that urinary tract stem cells could be used to treat urological disorders such a kidney disease, urinary incontinence, and erectile dysfunction. However, Zhang is optimistic that they can also be used to treat a wider variety of treatment options, such as making replacement bladders, urine tubes, and other urologic organs.

Since these stem cells come from the patient’s own body, they can have a low chance of being rejected by the immune system. Also, they do not cause tumors when implanted into laboratory animals.

In their latest work, Zhang and his colleagues obtained urine samples from 17 healthy individuals whose ages ranged from five to 75 years old. Even though these stem cells are only one of a large collection of cells in urine, isolating urinary stem cells from urine only requires minimal processing.

A single USC (inset) is followed through different passages (p0-p12). The cells were expanded to a colony were cultured in KSFM-EFM medium with 5% serum and images recorded with passage. Images shown at x100
A single USC (inset)
is followed through different passages (p0-p12). The cells were expanded to a colony were cultured in
KSFM-EFM medium with 5% serum and images recorded with passage. Images shown at x100

In the laboratory, Zhang and his team differentiated the cells into derivatives of all three embryological layers (endoderm – skin and nervous tissue; mesoderm – bone, muscle, glands, and blood vessels; and endoderm – digestive system).

Differentiation of one USC clone into UCs and SMCs. (a) USCs (p3) t were used to differentiate into two distinct lineages. Culture in SMCs-lineage differentiation (2.5 ng/ml TGF-􀈕1 and 5 ng/ml PDGF-BB) and UCs-lineage differentiation (30 ng/ml EGF) medium was used for 14 days.
Differentiation of one USC clone into UCs and SMCs. (a) USCs (p3) t were used to
differentiate into two distinct lineages. Culture in SMCs-lineage differentiation (2.5 ng/ml TGF-􀈕1 and
5 ng/ml PDGF-BB) and UCs-lineage differentiation (30 ng/ml EGF) medium was used for 14 days.

After showing the multipotent nature of urinary tract stem cells in the laboratory, Zhang and others took smooth muscle cells and urothelial cells made from urinary tract stem cells and transplanted them into mice with tissue scaffolds that had been made from decellularized pig intestine. The scaffolds only had extracellular molecules and not cells. After one month, the implanted cells had formed multi-layered, tissue-like structures.

USCs were infected with BMP9 or control GFP and were injected subcutaneously into nude mice. i) Bony masses were only observed in mice implanted with BMP-transduced USCs at week 4. ii) The harvested bony masses were subjected to microCT imaging revealing the isosurface (left) and density heat maps (right).
USCs were infected with BMP9 or control GFP and were
injected subcutaneously into nude mice. i) Bony masses were only observed in mice implanted with
BMP-transduced USCs at week 4. ii) The harvested bony masses were subjected to microCT imaging
revealing the isosurface (left) and density heat maps (right).

Urinary tract stem cells or as Zhang calls them, urine-derived stem cells or USCs, have many cell surface characteristics of mesenchymal stem cells from bone marrow, but they are also like pericytes, which are cells on the outside of small blood vessels. Zhang and others suspect that USCs come from the upper urinary tract, including the kidney. Patients who have had kidney transplants from male donors have USCs with a Y chromosome in them, which suggests that the kidney is a source or one of the sources of these cells.

Determination of USC source. Several clones of USCs (p3) were cultured and analyzed for expression of kidney-lineage marker. (a) FISH (left) and amelogenin gene PCR analysis (right) analysis of USCs isolated from urine obtained from a male donor-to-female recipient kidney transplant for presence of Y-chromosome (L: DNA ladder, M: male control, F: female control, A4: USC from male donor-to-female recipient urine sample, N: negative control).
Determination of USC source. Several clones of USCs (p3) were cultured and analyzed for
expression of kidney-lineage marker. (a) FISH (left) and amelogenin gene PCR analysis (right)
analysis of USCs isolated from urine obtained from a male donor-to-female recipient kidney transplant
for presence of Y-chromosome (L: DNA ladder, M: male control, F: female control, A4: USC from
male donor-to-female recipient urine sample, N: negative control).

Even more work needs to be done before we can truly become over-the-moon excited about these cells as a source of material for regenerative medicine, Zhang’s work is certainly an encouraging start.

See Shantaram Bharadwaj, et al., Multi-Potential Differentiation of Human Urine-Derived Stem Cells: Potential for Therapeutic Applications in Urology. Stem Cells 2013 DOI: 10.1002/stem.1424.

Gum-Based Stem Cells For Regenerative Medicine


The gums are also known as the gingivae, and this soft tissue serves as a biological barrier that covers the oral cavity of the maxillae and mandible (upper and lower jawbones). The gingivae also harbor a stem cell population known as gingival mesenchymal stem cells or GMSCs.

“Oh that’s a big surprise,” you say, “another mesenchymal stem cell population found in the body.” Well this one is a big deal because of its tissue of origin. Most MSCs are formed during embryonic development from cells that originate from the mesoderm, the embryonic tissue that lies between the skin of the embryo and the gut. Mesoderm forms the muscles, bones, connective tissue, adrenal glands, circulatory system, kidneys, gonads, and some other vitally important tissues.

Mesoderm

However, in the head, a large number of tissues are formed from “neural crest cells.” Neural crest cells hail from the top of the neural tube, which is the beginnings of the spinal cord. The dorsal-most portion of the neural tube contains a population of cells that move out of the neural tube and colonize the embryo to form a whole host of tissues. These include: Neurons, including sensory ganglia, sympathetic and parasympathetic ganglia, and plexuses, Neuroglial cells, Schwann cells, Adrenal medulla, Calcitonin-secreting cells, Carotid body type I cells, Epidermal pigment cells, Facial cartilage and bone Facial and anterior ventral skull cartilage and bones, Corneal endothelium and stroma, Tooth papillae, Dermis, smooth muscle, and adipose tissue of skin of head and neck, Connective tissue of salivary, lachrymal, thymus, thyroid, and pituitary glands, Connective tissue and smooth muscle in arteries of aortic arch origin. Wow, that’s a lot of stuff. I think you can see that these neural crest cells are important players during embryonic development.

Neural_Crest

Songtao Shi, from the Ostrow School of Dentistry, University of Southern California and his co-workers demonstrated that approximately 90% of GMSCs are derived from cranial neural crest cells and 10% are derived from mesoderm. This is important because neural crest-based stem cells seem to have greater plasticity.

Shi and his team compared mesodermally derived MSCs with GMSCs and the neural crest derived MSCs have a greater ability to differentiate into neural cells and cartilage-making cells.

In a mouse model of colitis in which mice are fed dextran sulfate sodium, which induces colitis in the mice, the neural crest derived MSCs did a better job of relieving the inflammation associated with colitis than their mesodermally derived counterparts.

Shi admits that further research on these stem cells must be done in order to better understand them and their functional roles. Shi is especially interested in the functional interaction between the neural crest derived MSCs in the gum and the mesodermally derived MSCs. Also, their potential for suppressing inflammation in particular diseases of the immune system and wound healing needs to be examined in some detail.

A New Blood Vessel-Generating Stem Cell Discovered With Therapeutic Potential


The laboratory of Petri Salven at the University of Helsinki, Helsinki, Finland, has discovered a new type of stem cell that play a decisive role in the growth of new blood vessels. These stem cells are found in the walls of blood vessels and if protocols are developed to isolated these stem cells, they might very well provide news ways to treat cardiovascular diseases, cancer and many other diseases.

The growth of new blood vessels is known angiogenesis. Angiogenesis is required for the repair of damaged tissues or organs. A downside of angiogenesis is that tumors often secrete angiogenic factors that induce the circulatory system to remodel itself so that new blood vessels grow into the tumor and feed it so that it can grow faster. Thus angiogenesis research tries to promote the growth of new blood vessels when they are needed and inhibit angiogenesis when it is unwanted.

Several drugs that inhibit angiogenesis have been introduced as adjuvant cancer treatments. For example, the drug bevacizumab (Avastin) is a monoclonal antibody that specifically recognizes and binds to an angiogenic factor known as vascular endothelial growth factor or VEGF. When VEGF receptors on the surface of normal endothelial cells. When VEGF binds to receptors on the surfaces of endothelial cells, a signal is sent within those cells that initiate the growth and survival of new blood vessels. Bevacizumab binds tightly to VEGF, which prevents it from binding and activating the VEGF receptor.

Other angiogenesis inhibitors include sorafenib (Nexavar) and sunitinib (Sutent), which are small molecular inhibitors of the receptors that bind the angiogenic factors and the downstream targets of those receptors. Unfortunately, the present crop of angiogenesis inhibitors are not all that effective under certain conditions and they are also extremely expensive and have some very undesirable side effects.

Professor Salven has studied angiogenesis for some time, and his research has focused on the endothelial cells that compose blood vessels. Where do these cells come from and how can we make more or less of them as needed?

A long-standing assumption by scientists in the angiogenesis field was that new endothelial cells came from stem cells found in the bond marrow. This assumption makes sense since there are several stem cell populations in bone marrow that express blood vessel markers and can form blood vessels in culture. However, in 2008, Salven’s group published a paper that demonstrated that new endothelial cells could not come from bone marrow stem cells (see Purhonen S, et al., (2008). Proc Natl Acad Sci U S A. 105(18): 6620-5). Therefore, the mystery remained – from where do new endothelial cells come?

Salven has recently solved this conundrum in his recent paper that appeared in PLoS Biology. According to Salven, “We succeeded in isolating endothelial cells with a high rate of division in the blood vessels of mice. We found that these same cells in human blood vessels and blood vessels growing in malignant tumors in humans. These cells are known as vascular endothelial stem cells, abbreviated VESC. In a cell culture, one such cell is able to produce tends of millions of new blood vessels wall cells.”

Slaven continued: “Our study found that these important stem cells can be found as single cells among the ordinary endothelial cells in blood vessel walls. When the process of angiogenesis is launched, these cells begin to produce new blood vessel wall cells.”

Salven’s colleagues have tested the effects of these new endothelial cells in mice. A particular mouse strain that carries a mutation in the c-kit gene was examined in these experiments. The c-kit gene encodes a cell surface protein called CD117, which is a vital element in the cells that form blood vessels. IN these c-kit mutant mice, new growth of new blood vessels was very poor and the growth of malignant tumors was also quite poor. However, if new stem cells from animals that did not possess a mutation in the c-kit gene were implanted into these mutant mice, blood vessels quickly formed.

As previously mentioned, the cell surface protein CD117 does seem to mark VESCs, but other cells other than VESCs have CD117 on their surfaces. Therefore, isolating all CD177-expression cells only enriches preparations for VESCs; it does not isolate VESCs. Presently, Salven and his group are searching for better surface molecules that can be used to more effectively isolated VESCs from surrounding tissue. If this isolation succeeds, then it will be possible to isolated and propagate VESCs from patients with cardiovascular diseases and expand them in culture for therapeutic purposes.

Another potentially fertile field of research is to find a way to inhibit the activity of VESCs to prevent tumors from remodeling the circulatory system. By cutting of their blood supply, tumors will not only grow slower, but also not spread nearly as quickly.

See: Fang S, Wei J, Pentinmikko N, Leinonen H, Salven P (2012) Generation of Functional Blood Vessels from a Single c-kit+ Adult Vascular Endothelial Stem Cell. PLoS Biol 10(10): e1001407. doi:10.1371/journal.pbio.1001407

Preliminary Results of Stem Cell Treatment for Stroke Show No Major Side Effects


A collaborative effort between physicians and scientists at the University of Texas Health Science Center in Houston and other centers, has spawned a clinical trial to test a stem cell treatment for stroke patients.

The lead researcher, Sean Savitz, professor of neurology and the director of the stroke program at UT, presented the first results from 10 stroke patients who were treated with stem cells at the World Stroke Congress in Brasilia, Brazil. This clinical trial is the only randomized, double-blind, placebo-controlled intra-arterial clinical trial in the world for ischemic stroke. The goal of this trial is to test the safety and efficacy of a therapy developed by a company called Aldagen Inc. (a wholly-owned subsidiary of Cytomedix Inc.) that uses a patient’s own bone marrow stem cells to treat stroke patients.

In this clinical trial, after a patient has suffered a stroke, the bone marrow stem cells are administered between 13-19 days after the stroke. This therapy, which is known as ALD-401, uses a technology developed and owned by Aldagen to isolate cells from bone marrow that express very high levels of a particular enzyme. This enzyme marks the cells that express it as stem cells. Pre-clinical studies with these isolated cells in mice showed that mice that had suffered from a stroke showed enhanced recovery when given intra-arterial infusions of these stem cells.

All patients infused with these stem cells will be monitored for 12 months after the infusion. The patient’s mental and physical functions will be closely watched, and any side effects from the infusions will be noted and treated.

According the Dr. Savitz, “We have been approved by the Data Safety Monitoring Board (DSMB) to move the study into the next phase, which will allow us to expand the number of sites in order to complete enrollment.”

Since the 10 people treated in this study have not shown any adverse side effects, Savitz wants to eventually enroll 100 patients. According to the submitted protocol for this study, the initial study only placed 10 patients at risk for this untested treatment. Therefore, before more patients could be enrolled in the clinical trial, the Food and Drug Administration had to review the safety data on the first ten patients before more could be enrolled. The FDA has approved the move to the next phase of this clinical trial.

In pre-clinical trials, some of which were conducted at the UTHealth Medical School, bone marrow stem cells promoted the repair of the brain after an ischemic stroke. Savitz and his colleagues induced stroked in rats and measured the amount of oxygen that flowed into the brain by means of Magnetic Resonance Imaging or continuous laser Doppler flowmetry. In rats that made been given injections of bone marrow-derived stem cells, the oxygen flow to the brain was significantly better than in rats that had suffered a stroke but had not been given the stem cell treatments. Savitz’s group also showed that a molecule that dilates blood vessels called nitric oxide was necessary to keep the vessels open and to allow entry of the stem cells into the brain so that they could repair the damage. When Savitz and his group prevented nitric oxide synthesis with an inhibitor called L-NAME, the infused stem cells were unable to enter the brain and fix it, and oxygen flow to the brain tanked. It was the strength of these pre-clinical studies that convinced the FDA to approve this present human clinical trial that tests this same procedure in human patients.

Ischemic strokes result from blood clots in the tiny vessels in the brain, which starves portions of the brain for oxygen, thus killing off brain cells. Stroke is the leading cause of disability in the United States and the fourth most common cause of death, according the statistics provided by the Centers for Disease Control and Prevention in Atlanta, Georgia.

Stem Cell Therapy for Inflammatory Bowel Disease in the Works


Stem cells from umbilical cord blood have the ability to migrate to the intestine and integrate into the tissues. This integration allows umbilical stem cells to contribute to the cell population of the gastrointestinal tract. This biological property of umbilical cord stem cells might make them ideal treatments for inflammatory bowel disease (IBD).

One million Americans have IBDs such as Crohn’s disease or ulcerative colitis. Crohn’s disease can affect the small and large intestine, whereas the ulcerative colitis is usually restricted to the colon (large intestine). Also Crohn’s disease displays patchy lesions whereas ulcerative colitis consists of continuous stretches of inflammation. These disease are characterized by frequent diarrhea and abdominal pain. Patients who suffer from ulcerative colitis also tend to have bloody stools, and if left untreated, the blood loss can be extensive. Ulcerative colitis only affects the upper layer of the large intestine, whereas Crohn’s disease can affect multiple layers of the intestine.

There are no cures for IBDs, but there are drug treatments. In the case of ulcerative colitis, the drug prednisone is used to calm down fulminant outbreaks and then mesalamine (5-aminosalicylic acid) or sulfasalazine are used to maintain the disease in a calm or quiescent state. Mesalamine is present in an oral form marketed as Asacol or Pentasa. The difference between Asacol and Pentasa is in the outer chemical coating, since Pentasa packages its drug in coated microgranules, which enables a prolonged release of the active substance throughout the intestinal tract, from duodenum to the rectum. Therefore Pentasa is more useful for Crohn’s patients. Asacol is a delayed release enteric-coated tablets that releases the active ingredient only in the colon. Mesalamine is also available in an enema form (Rowasa)

If these drugs do not work, biologic treatments such as Infliximab (Remicade), adalimumab (Humira) and Golimumab (Simponi) are commonly used to treat patients with Ulcerative Colitis, but these drugs suppress the immune system and can raise the risk of severe illness. Corticosteroids are also used, but long-term use of these drugs also causes severe side effects.

Thus, if the drugs do not work, the treatment can be as bad as the disease itself. Certainly a treatment that regenerates the bowel is preferable, and a stem cell treatment seems to fit the bill.

In an article in the journal Hepatology, the senior author, Graca Almeida-Porada, a professor at Wake Forest Baptist Medical Center’s Institute for Regenerative Medicine, and her colleagues argue that a special stem cell population known as endothelial colony-forming cells, found in umbilical cord blood and bone marrow and circulating blood, can play a definite role in the treatment of IBDs.

Almeida-Porada said, “These cells are involved in the formation of blood vessels and may prove to be a tool for improving the vessel abnormalities found in IBD.”

In 1997, scientists discovered that these endothelial colony-forming stem cells contribute to the formation of blood vessels in embryos, and adults. This study initiated investigations of the capacity of endothelial colony-forming cells as potential therapeutic agents. Clinical studies have shown that endothelial colony-forming cells can improve reduced blood flow to limbs and can also treat heart disease.

Unfortunately, few studies have examined the ability of endothelial colony-forming cells to home to different organs and integrate into their circulatory systems. Thus, Almeida-Porada wanted to examine the ability of endothelial colony-forming cells to integrate into the intestine. Also, since abnormal blood vessels are a hallmark of IBDs, they might be a potential treatment for IBDs.

In this experiment, fetal sheep at 59-65 days gestation were injected with human endothelial colony-forming cells (EPCs). At 11 weeks gestation, the fetal sheep were examined to determine if the human cells had integrated into the fetal sheep tissue. Researchers found that the infused cells had migrated into the intestine and had made significant contributions to the cell population of the bowel.

According to Almeida-Porada: “The study shows that the cells can migrate to and survive in a healthy intestine and have the potential to support vascular health. Our next step will be to determine whether cells can survive in the ‘war’ environment of an inflamed intestine.”

Interestingly, Almeida-Porada’s team found that endothelial colony-forming cells also colonized the liver of the fetal sheep. Although smaller numbers of cells reached the liver as opposed to the intestine, new strategies might enhance the therapeutic potential for these cells with respect to the liver.

T Cells from Engineered Stem Cells Clear HIV from Infected Mice


A research team at UCLA has published a proof-of-principal study that demonstrates that human stem cells can be genetically engineered to create HIV-fighting cells. Their study was published on April 12, 2012 in the open journal PLoS Pathogens. This paper shows for the first time that engineering stem cells to form immune cells that specifically target HIV is effective in suppressing the virus in living tissues in an animal model. Lead investigator Scott G. Kitchen, an assistant professor of medicine in the division of hematology and oncology at the David Geffen School of Medicine at UCLA and a member of the UCLA AIDS Institute said: “We believe that this study lays the groundwork for the potential use of this type of approach in combating HIV infection in infected individuals, in hopes of eradicating the virus from the body.”

In previous research, this research group took a special group of immune cells known as CD8 cytotoxic T lymphocytes from an HIV-infected individual. CD8-positive T cells specifically attack virus-infected cells and destroy them so that they do not anymore virus. After they collected CD8 T cells from HIV-infected individuals, they grew them in culture. Next they established that these cells could attack and destroy HIV-infected cells in culture. The next step was to determine if these same cells could attack HIV-infected cells in a living organism.

When CD8 cells engage an infected cell, they use a molecule on their surfaces called the “T cell Receptor” (TCR). The TCR is an unusual protein that is encoded by a gene complex that consists of many copies of different versions of various regions of the TCR. During the development of the T cell one gene from each of these copies is chosen and spliced together with one copy from each of the other regions. The result is a TCR molecule that is unique to the T cell that makes it. These TCRs are able to bind to foreign substances and when they do, the T cell becomes activated. In the case of CD8 cytotoxic T cells, the binding of foreign substances on the surfaces of cells tell the cells that something dangerous is afoot inside the cell. Therefore, it secretes toxic chemicals that kill the cell.

In previous research carried out by the UCLA team, they isolated CD8 cytotoxic T lymphocytes from an HIV-infected individual and identified the genes from the TCR. Since the TCR guides the T cell in recognizing and killing HIV-infected cells, they reasoned that by making more of the T cells that recognize HIV-infected cells they could potentially provide HIV-infected animals with a way to clear the virus from the cell. The problem in HIV-infected individuals is that CD8 cells that are specific for HIV-infected cells do not exist in great enough quantities to clear the virus from the body.

To solve this problem, the researchers cloned the receptor and used this to genetically engineer human blood stem cells. They then placed the engineered stem cells into human thymus tissue that had been implanted in mice. Now the engineered T cells were observed interacting in a living organism. The engineered stem cells developed into a large population of mature, multi-functional HIV-specific CD8 cells that were able to specifically target HIV-infected cells with HIV proteins on their surfaces. Interestingly, the research group found that HIV-specific T cell receptors have to be matched to an individual in much the same way an organ is matched to a transplant patient.

In the current study, the UCLA group similarly engineered human blood stem cells and discovered that they can form mature T cells that can attack HIV in tissues where the virus resides and replicates. To show this they used the humanized mouse. This animal is a rodent with a human immune system. In these animals, HIV infection closely resembles the disease and its progression in humans.

Two-six weeks after introducing their engineered blood stem cells into the peripheral blood of the mouse, they found that the number of CD4 “helper” T cells — which become depleted as a result of HIV infection — increased and levels of HIV in the blood decreased. CD4 cells or T-helper cells are white blood cells that play a vital role in the immune system. These results indicated that the engineered cells were capable of developing and migrating to the organs to fight infection there.

There is, however, a potential weakness with this study: Human immune cells reconstituted at a lower level in the humanized mice than they would in humans, and as a result, the mice’s immune systems were mostly, though not completely, reconstructed. Because of this, HIV may be slower to accumulate mutations in the mice than in human hosts. Thus the use of multiple, engineered T cell receptors may be one way to adjust for the higher potential for HIV mutation in humans.

Kitchen sounded this optimistic note: “We believe that this is the first step in developing a more aggressive approach in correcting the defects in the human T cell responses that allow HIV to persist in infected people.”

Mesenchymal Stem Cells Can Potentially Treat Non-Union Fractures


Sometimes bone fractures have trouble healing. Such fractures are called “stable non-union fractures,” and they represent major clinical challenges. There are few treatment options for stable non-union fractures, and such conditions represent a major health issue. Fracture treatment options include bone grafting and/or remodeling of the fracture through open reduction and internal fixation (ORIF). In general, ORIF involves the use of plates, screws or even an intramedullary rod to stabilize the bone. Other, less-invasive care options such as treatment with bone morphogenic proteins (BMPs) and other types of bone stimulators are also available.

Can mesenchymal stem cells help such fractures heal better? Centeno and his colleagues at Regenexx conducted their own original research study that shows that some patients probably can be helped by the same sorts of procedures that they use to treat knees. This procedure includes bone marrow aspiration from the crest of the top of the pelvis (the ilium). The mesenchymal stem cells are isolated from the bone marrow and cultured for a few days. Then the expanded and prepared mesenchymal stem cells are applied precisely to the area that needs healing by means of c-Arm fluoroscopy. Sounds good? Yes it does, but to show that it works requires a tried and true clinical study. Centeno’s group has done exactly that, but the number of patients in this study is small. Still this paper represents one of the first examinations of stem cells treatments for stubborn fractures they resist healing.

In this paper, six patients were evaluated. All six had chronic fractures that had not healed (chronic fracture non-unions). There were four women and two men in this experimental group, and they had suffered from these fractures for an average of 8.75 months. The range of the times the patients had lived with these fractures ranged from 4- 18 months, but one patient had lived with their fracture for over 100 months.

All six patient were treated with their own stem cells that were extracted by means of bone marrow aspirations, cultured in the laboratory for 3- 7 passages, and then suspended in phosphate-buffered saline and lysate from peripheral blood platelets. All mesenchymal stem cells were assessed by microscopic examination and flow cytometry to ensure that they expressed the proper surface proteins. Mesenchymal stem cells were then injected percutaneously by means of a sterile trocar, guided by fluoroscopic imaging into the site of the stubborn fracture. To determine if the fractures healed, patients were scanned with X-rays, and computerized tomographic (CT) imaging.

Only five of the patients could be contacted for follow up, but the results are somewhat encouraging. The first patient was a 37-year old smoker (1/4 pack a day) who had suffered with a non-healing fracture for 9 months, but only 2 months after the treatment, was back to “full activities.” An X-ray at 14 months after healing showed excellent healing of the fracture.

The second patient was an 82-year old woman who had suffered from several fractures because of osteoporosis. She had stem cells implanted into her fractured back, and by eight months after the treatment regime, she showed advanced healing of her back fracture. Within four to six weeks after the transplant, the patient walked normally for her age and enjoyed new activities, albeit with age restrictions.

The third patient was a 68-year old woman with a long-time history of multiple sclerosis. She had an 18-month fracture that had not healed in her foot and had to walk with a walking boot immobilizer. Follow-up X-rays showed that after 2 and 6 months she had moderate healing of her fracture and returned to normal activities by 4-6 weeks after the transplant. Unfortunately, she dropped an object on the same foot at 7 months after the procedure and no further follow-up seemed practical.

The fourth patient is a 59 year old woman who had a 40-year history of a traumatic hip fracture and hamstring tear. Unfortunately, her follow up x-rays failed to show any signs of healing.

The fifth patient is a 67-year old man with a 4-month lower leg fracture. He also had type II diabetes mellitus, and coronary artery disease. This patient returned to full walking 4-6 weeks after the procedure. 5 months after the transplant, his x-rays showed signs of healing. No further follow up was possible.

Four of the six patients treated with their own mesenchymal stem cells showed good healing of the fractures that resisted healing through conventional means. The only fracture that showed no signs of healing was a 40-year old fracture that was difficult to immobilize. It is possible that the lack of immobilization caused the bone, which reacts to stress forces, caused this fracture that had adapted to being broken, and could no longer produce signals necessary for repair.

While this study is preliminary, the results support the hypothesis that a patient’s own mesenchymal stem cells are a potential alternative treatment for the treatment of stubborn, fractures that refuse to heal.

Phase I Study of Embryonic Stem Cell-Derived Retinal Pigment Epithelium Cells Shows Early Signs of Success


Several different diseases cause deterioration of the eye and plunge aging or even young men and women into a life of blindness. Several of these genetic diseases affect the tissues that reside at the back of the eye, which is collectively called the retina. The retina contains two main layers; an inner neural retina and an outer pigmented retina.

The neural retina is filled with photoreceptors and cells that process the outputs from the photoreceptor cells and send them to the brain. The pigmental retina contains the retinal pigmented epithelium, which plays a central role in retinal physiology. The retinal pigmented epithelium or RPE forms the outer blood-retinal barrier and supports the function of the photoreceptors. Many diseases the adversely affect the retina called “retinopathies” involve a disruption of the epithelium’s interactions with the neural retina. Other types of retinopathies are caused by uncontrolled proliferation of the RPE cells.

Transplantation of RPE cells can help treat patients that have various types of retinopathies (see Lund RD et al.,Cloning Stem Cells.2006 Fall;8(3):189-99).  However, embryonic stem cells can be made into copious quantities of RPEs rather easily (Huang Y, Enzmann V, Ildstad ST. Stem Cell Rev. 2011 Jun;7(2):434-45).  Therefore, it was only a matter of time before clinical trials were instigated with embryonic stem cell-derived RPEs.

In recent edition of the journal The Lancet, Steven Schwartz and colleagues have reported the first clinical results from patients treated with embryonic stem cell-derived RPEs.  A patient with “Stargardt’s macular dystrophy,” which is the most common form of pediatric macular degeneration, and a patient with dry age-related macular degeneration, the leading cause of blindness in the developed world, each received a subretinal injection of RPEs derived from embryonic stem cells (ESCs).  Both of these disorders are not treatable at present, but both also result from degeneration of the RPE.  Loss of RPE cells causes photoreceptor loss and progressive vision deficiency.

Schwartz and colleagues differentiated the hESCs into RPE cultures that showed greater than 99% purity.  Then they injected 50,000 RPE cells into the subretinal space of one eye in each patient. Each patient received anti-rejection drugs (low-dose tacrolimus and mycophenolate mofetil) just in case the immune system tried to attack the transplanted RPE cells.

There results are hopeful, since, after 4 months, both patients show no sign of retinal detachment, hyperproliferation, abnormal growths, intraocular inflammation, or teratoma formation.  Anatomical evidence of the injected cells was difficult to confirm in the patient with age-related macular degeneration, but was present in the patient with Stargardt’s macular dystrophy.

Both patients showed some visual improvements.  The patient who suffers from age-related macular degeneration improved in visual acuity, since she was able to recognize 28 letters in a visual acuity chart, whereas before he procedure, she was able to identify only 28 (improvement from 20/500 vision to 20/320).  The patient with Stargardt’s macular dystrophy went from counting fingers and seeing only one letter in the eye chart by week 2, and to a stable level of five letters (20/800) after 4 weeks.  This patient also showed subjective improvement in color vision, contrast, and dark adaptation in the treated eye.

These results are highly preliminary and the improvements are slight, but the progressive nature of these eye diseases suggests that the injections largely worked.  Before we can crack our knuckles for joy, we will need to see improvements with more than two patients.  But the fact that the treated eye showed improvements not seen in the untreated eye is highly suggestive that the transplanted RPEs are improving the health of the photoreceptors in the neural retina.  The eye is an ideal place to do such research because it is one place in the body that is not regularly patrolled by the immune system, and foreign cells placed in the eye tend to receive far less scrutiny from the immune system than other parts of the body.

I am glad for these patients, but I am troubled by this experiment.  Other types of stem cells can be converted into RPEs (Uygun BE, Sharma N, Yarmush M. Crit Rev Biomed Eng. 2009;37(4-5):355-75.).  Also, there are other stem cells in the eye that, if properly investigated might possess the ability to form RPEs (Bhatia B, et al.,Exp Eye Res. 2011 Dec;93(6):852-61).  Why was this experiment first done with cells that require the death of early human embryos?  The safety concerns with ESCs makes the clinical trial far more expensive and slower.  While the embryos sacrificed to make these RPEs have long since died, the ESC culture is doing some clinical good.  However, how would we feel about cell lines made from children who were murdered by a sadistic scientist?  Would you receive treatments from them given what you know about their origin?  So while this experiment shows hope, it also leads to controversy as well that is not being discussed as deeply as it should.

Making Older Mice Younger with Stem Cell Injections


University of Pittsburgh scientists have used stem cells derived from younger young mice to revitalize older mice. They used mice that were bred to age quickly, but after these stem cell injections, they seemed to have sipped from the fountain of youth. These stem cells were derived from muscles of young, healthy animals, and instead of becoming infirm and dying early as untreated mice did, the injected animals improved their health and lived two to three times longer than expected. These findings were published in the Jan. 3 edition of Nature Communications.

Previous research has revealed stem cell dysfunction, such as poor replication and differentiation, in a variety of tissues in old age. However it is not clear whether that loss of function contributes to the aging process or is a result of it. Senior investigators in this work were Johnny Huard, Ph.D., professor in the Departments of Orthopaedic Surgery and of Microbiology and Molecular Genetics, Pitt School of Medicine, and director of the Stem Cell Research Center at Pitt and Children’s Hospital of PIttsburgh of UPMC, and Laura Niedernhofer, M.D., Ph.D. associate professor in Pitt’s Department of Microbiology and Molecular Genetics and the University of Pittsburgh Cancer Institute (UPCI).

Niedernhofer explained: “Our experiments showed that mice that have progeria, a disorder of premature aging, were healthier and lived longer after an injection of stem cells from young, healthy animals. That tells us that stem cell dysfunction is a cause of the changes we see with aging.”

The research team examined a stem/progenitor cell population derived from the muscle of mice engineered to suffer from a genetic disease called progeria. Progeria is a genetic disease that causes premature aging. Human patients with progeria age extremely quickly and die at a very young age from old age. Muscle-derived stem cells from progeria mice were fewer in number, did not replicate as often, didn’t differentiate as readily into specialized cells and were impaired in their ability to regenerate damaged muscle in comparison to those found in normal rodents. The same defects were discovered in the stem/progenitor cells isolated from very old mice.

Dr. Huard said: “We wanted to see if we could rescue these rapidly aging animals, so we injected stem/progenitor cells from young, healthy mice into the abdomens of 17-day-old progeria mice. Typically the progeria mice die at around 21 to 28 days of age, but the treated animals lived far longer – some even lived beyond 66 days. They also were in better general health.”

As the progeria mice age, they lose muscle mass in their hind limbs, hunch over, tremble, and move slowly and awkwardly. Affected mice received an injection of stem cells just before showing the first signs of aging were more like normal mice, and they grew almost as large. Closer examination showed new blood vessel growth in the brain and muscle, even though the stem/progenitor cells weren’t detected in those tissues. However, the injected cells didn’t migrate to any particular tissue after injection into the abdomen.

Niedernhofer noted: “This leads us to think that healthy cells secrete factors to create an environment that help correct the dysfunction present in the native stem cell population and aged tissue. In a culture dish experiment, we put young stem cells close to, but not touching, progeria stem cells, and the unhealthy cells functionally improved.”

Animals that age normally were not treated with stem/progenitor cells, but these provocative findings urge further research. They hint that it might be possible one day to forestall the biological declines associated with aging by delivering a shot of youthful vigor, particularly if specific rejuvenating proteins or molecules produced by the stem cells could be identified and isolated.