Hair Loss Cure Isn’t Here Yet, But Experimental Stem Cell Approach Looks Promising

While a cure for hair loss is some years away, a California research team has brought us much closer that such a treatment becoming a reality. Hair loss, a condition that affects 50 million men and 30 million women in the U.S. alone, might fall to stem cell treatments some day.

Dr. Alexey Terskikh led the team from the Sanford-Burnham Medical Research Institute in La Jolla, California that showed that stem cells derived from human skin can be used to grow hair in mice.

“The method is a marked improvement over current methods that rely on transplanting existing hair follicles from one part of the head to another,” Dr. Terskikh, who serves as an associate professor at the institute. “Our stem cell method provides an unlimited source of cells from the patient for transplantation and isn’t limited by the availability of existing hair follicles.”

Conventional hair transplantation and other hair restoration treatments that are presently in use must use whatever hair the patient has left. However a stem cell-based procedure could, in theory, grow all kinds of hair on the heads of completely bald men and women.

“If this approach is proven to work in humans, it will change existing treatments radically,” Dr. Nicole Rogers, a dermatologist and hair transplant surgeon in New Orleans, told The Huffington Post in an email.

Dr. Marie Jhin, a dermatologist in San Francisco and an adjunct clinical instructor at Stanford University, feels the same way about Terskikh’s results. If this treatment pans out, she said that it “absolutely would be a breakthrough.”

Rogers, however, tempered her excitement by advising caution and skepticism, since there have been many “fits and starts” over the years in the hair-restoration field. Rogers added that the Sanford-Burnham group must face many challenges in order to replicate their results in large-scale human trials.

The technique exploits the ability of human pluripotent stem cells to differentiate into almost any other adult cell type in the body. Terskikh and his collaborators differentiated induced pluripotent stem cells made from reprogrammed skin cells into the dermal papilla cells that regulate the formation and growth of hair follicles. Furthermore, when they injected these cells into the lower layers of the skin of mice, they grew hair.

Close-up photograph showing new hair growth | Sanford-Burnham Medical Research Institute
Close-up photograph showing new hair growth | Sanford-Burnham Medical Research Institute

Human dermal papilla cells are unsuitable for conventional hair transplants because quickly lose their hair-growing potency and cannot be obtained in necessary numbers for clinical purposes.

Terskikh wisely did not prognosticate when they would be able to extend their protocol to treat hairless humans. The next step, according to Terskikh is to secure a partner to fund future research into this area.

University of Iowa Team Creates Insulin-Producing Cells from Skin Cells

A research team from the University of Iowa has designed a protocol that can create insulin-producing cells that help normalize blood-sugar levels in diabetic mice from skin cells. This discovery represents one of the first steps toward developing patient-specific cell replacement therapy for Type 1 diabetes. This research, which was led by Nicholas Zavazava from the department of internal medicine, was published in the journal PLoS ONE.

Zavazava and his coworker used human skin cells taken from punch biopsies and reprogrammed them to into induced pluripotent stem cells. These induced pluripotent stem cells were then differentiated in culture into pancreatic insulin-producing beta cells.

In culture, Zavazava’s cell made insulin in response to increased concentrations, but when they were implanted into diabetic mice, these cells responded to glucose, secreted insulin and worked to lower the blood-sugar levels in the mice to normal or near-normal levels.

Mind you, these induced pluripotent stem cell-derived beta cells were not as effective as pancreatic cells in controlling blood sugar levels, according to Zavazava in a UI news release. However, Zavazava and his team views the cells’ response in mice as an “encouraging first step” toward the goal of generating effective insulin-producing cells that potentially could be used to not just treat but cure Type 1 diabetes in humans.

“This raises the possibility that we could treat patients with diabetes with their own cells,” Zavazava said. “That would be a major advance, which will accelerate treatment of diabetes.”

Zavazava is also a member of UI’s Fraternal Order of Eagles Diabetes Research Center. This center is one of several groups whose aim is to create an alternative source of insulin-producing cells that can replace the pancreatic beta cells that die off in people with Type 1 diabetes.

According to the UI news release, this study is the first to use human induced pluripotent stem cells instead of embryonic stem cells to generate insulin-producing pancreatic beta cells. This protocol has the advantage of creating beta cells from a patient’s own cells include. This would eliminate the need to wait for a donor pancreas, since pancreas transplants are an option for treating Type 1 diabetes, but the demand for transplants is much greater than the availability of organs from deceased donors. The use of induced pluripotent stem cells would also eliminate the need for transplant patients to take immunosuppressive drugs. Finally, the use of induced pluripotent stem cells would also avoid the ethical concerns with treatments based on embryonic stem cells.

Fat-Based Stem Cells Prevent Blood-Brain Barrier Disruption After a Stroke

If something lodges in the blood vessels that feed the brain – say a blood clot, piece of bone marrow after a bone has been broken, or tissue debris from damaged tissue – the brain undergoes a loss of blood flow. Since the brain received its oxygen and nutrients from the bloodstream, blockage of the vessels that feed the brain can lead to the death of brain cells.

Such a phenomenon is called a stroke or a Trans-Ischemic Attack. However, if the heart stops, blood flow to the brain ceases; not because of blockage of the blood vessels that feed the brain, but because the pump that propels through the bloodstream has stopped and, therefore, blood flow stops. Such a condition is known as global cerebral ischemia or GCI.

GCI is one of the most challenging clinical issues encountered during cardiac arrest and, unfortunately, typically indicates a poor prognosis. Severe neurological damage develops in 33%–50% of GCI patients who have survived a cardiac arrest that was documented by a medical professional. In those rare cases of survival after cardiac arrest that was not documented by a medical professional, the percentage of neurological defects is 100%. I hope this convinces you that CGI is a problem.

In order to treat GCI, physicians usually induce hypothermia, which lowers and maintains the core body temperature at 32°C–34°C. Presently, this is the only treatment regime that has been demonstrated to improve neurological recovery. Unfortunately, there are many technical difficulties in the application of this therapy. Special equipment is required, and complications such as blood clots and infection are perennial problems. Is there a better way to treat GCI?

Sang Won Suh from the Hallym University College of Medicine in South Korea and his colleagues have used fat-based mesenchymal stem cells to treat laboratory animals that have suffered GCI. The results of their study are encouraging.

Suh and his coworkers used Sprague-Dawley rats for this study. They anesthetized the rats and then clamped their carotid arteries to reduce blood flow to the brain for seven minutes. This effectively simulates GCI in these laboratory animals. After the clamps were removed, some animals were given one million fat-based mesenchymal stem cells, and others were simply restored by means of unclamping the carotid arteries plus fluid reconstitution. The rats were subjected to behavioral tests three days before the procedure and seven days after it. These tests consisted of placing adhesive tape the forepaws of the animals and then measuring the day it tool for the animals to remove to adhesive tape. After the seventh day post-procedure, the rats were put down and their brains were examined for cell death, structure, blood vessel densities, and degree of inflammation.

When the brains of these animals were examined, it was clear that the animals that had received fat-based mesenchymal stem cells suffered much less cell death than the untreated animals.

Ischemia-induced degeneration of hippocampal neurons is decreased by MSC treatment. (A): Transient cerebral ischemia caused neuronal death in the hippocampal CA1 region 1 week after insult. Fluorescence images show several FJB+ neurons in the CA1 area after ischemia. Intravenous injection of MSCs after reperfusion provided protective effects on hippocampal neuronal death after ischemia compared with the vehicle-treated group. Scale bar = 100 μm. (B): Box whisker plot shows the quantification of neuronal degeneration in the hippocampus. The number of FJB+ neurons was significantly different among the groups on analysis of variance (p < .001). The post hoc analysis revealed significant differences between the vehicle control and MSC-treated groups (p < .001) and the vehicle control and sham operation groups (p < .001) in the hippocampus. ∗, statistically significant result from post hoc analysis; ○, outlier case. Abbreviations: FJB, Fluoro-Jade B; GI-MSC, human MSC-treated group after ischemia; GI-PC, vehicle control group after ischemia; MSC, mesenchymal stem cell; SH-PC, sham operation group with vehicle control.
Ischemia-induced degeneration of hippocampal neurons is decreased by MSC treatment. (A): Transient cerebral ischemia caused neuronal death in the hippocampal CA1 region 1 week after insult. Fluorescence images show several FJB+ neurons in the CA1 area after ischemia. Intravenous injection of MSCs after reperfusion provided protective effects on hippocampal neuronal death after ischemia compared with the vehicle-treated group. Scale bar = 100 μm. (B): Box whisker plot shows the quantification of neuronal degeneration in the hippocampus. The number of FJB+ neurons was significantly different among the groups on analysis of variance (p < .001). The post hoc analysis revealed significant differences between the vehicle control and MSC-treated groups (p < .001) and the vehicle control and sham operation groups (p < .001) in the hippocampus. ∗, statistically significant result from post hoc analysis; ○, outlier case. Abbreviations: FJB, Fluoro-Jade B; GI-MSC, human MSC-treated group after ischemia; GI-PC, vehicle control group after ischemia; MSC, mesenchymal stem cell; SH-PC, sham operation group with vehicle control.

In the figure above you can see a Fluoro-Jade B staining of these brains.  FJB stains detect dying cells.  As you can see, the brain from the rats that experienced GCI without any stem cell treatments had lots of dying cells in their brains.  The “sham” operated rats – rats that were operated, but their carotid arteries were not clamped – had no cell death in their brains.  The animals that had their carotid arteries clamped, but were given fat-based mesenchymal stem cells had a little cell death.  The graph above shows the vast differences between the stem cell-treated and the non-stem cell-treated groups.  Truly these are significant results.  Other experiments that detected Now this is no a surprise, since Ohtaki and others showed a very similar result in 2008 (Ohtaki H, et al. Proc Natl Acad Sci USA 105:1463814643).  Suh, and his group, however, took these experiments further to determine why these cells prevented cell death in the brain after GCI.

When Suh and his team examined the leakage of large proteins into the brain, they saw something quite remarkable; the mesenchymal stem cell-treated rats only leaked a little protein into their brains compared to the non-stem cell-treated rats.

Ischemia-induced blood-brain barrier (BBB) damage was reduced by MSC treatment. BBB damage in the hippocampus after ischemia shown. (A): Low-magnification photomicrographs showing IgG-stained coronal hippocampal sections. Sham-operated rats showed sparse IgG staining in the hippocampus. At 1 week after ischemia, the entire hippocampus was intensely stained with IgG immunoreactivity, indicating that substantial BBB damage had occurred in the vehicle-treated rats. Injection of MSCs after ischemia reduced the intensity of IgG staining in the hippocampus compared with that in the vehicle-treated group. Scale bar = 500 μm. (B): Box whisker plot shows the quantification of IgG intensity in the hippocampus. The intensity was significantly different among the groups on analysis of variance (p < .001), and post hoc analysis revealed significant differences between the vehicle control and MSC-treated groups (p < .001) and vehicle control and sham operation groups (p < .001) in the hippocampus. ∗, statistically significant result from post hoc analysis; ○, outlier case. Abbreviations: GI-MSC, human MSC-treated group after ischemia; GI-PC, vehicle control group after ischemia; MSC, mesenchymal stem cell; SH-PC, sham operation group with vehicle control.
Ischemia-induced blood-brain barrier (BBB) damage was reduced by MSC treatment. BBB damage in the hippocampus after ischemia shown. (A): Low-magnification photomicrographs showing IgG-stained coronal hippocampal sections. Sham-operated rats showed sparse IgG staining in the hippocampus. At 1 week after ischemia, the entire hippocampus was intensely stained with IgG immunoreactivity, indicating that substantial BBB damage had occurred in the vehicle-treated rats. Injection of MSCs after ischemia reduced the intensity of IgG staining in the hippocampus compared with that in the vehicle-treated group. Scale bar = 500 μm. (B): Box whisker plot shows the quantification of IgG intensity in the hippocampus. The intensity was significantly different among the groups on analysis of variance (p < .001), and post hoc analysis revealed significant differences between the vehicle control and MSC-treated groups (p < .001) and vehicle control and sham operation groups (p < .001) in the hippocampus. ∗, statistically significant result from post hoc analysis; ○, outlier case. Abbreviations: GI-MSC, human MSC-treated group after ischemia; GI-PC, vehicle control group after ischemia; MSC, mesenchymal stem cell; SH-PC, sham operation group with vehicle control.

The presence of the brown color indicated the presence of a protein in the brain that normally does not find its way to the brain unless the integrity of the blood-brain barrier is compromised.  As you can see, the non-treated animals have a truckload of this protein in their brains, which indicates that their blood-brain barriers are very leaky.  On the contrary, the stem cell-treated brains are not nearly as leaky and the sham operated brains are not leaky at all.

These results suggest that the stem cells help maintain the structural integrity of the blood-brain barrier in GCI patients and this prevents nasty things from the bloodstream, such as immune cells and so on from accessing the brain and ravaging it.  To test this hypothesis, Suh and others examined the brains for the presence of neutrophils, which are white blood cells that show up when inflammation occurs.  These cells are not found in the brain unless the blood-brain barrier is damaged.  Sure enough, brains from the sham-operated rats showed no signs of neutrophils, brains from the non-stem cell-treated rats were chock full of neutrophils, and the brains from the stem cell-treated rats only had a few neutrophils.

A conclusion from this paper states: “Administration of MSCs decreased the delayed neuronal damage in a transient global cerebral ischemia model by prevention of BBB disruption, endothelial damage, and neutrophil infiltration.”

Clearly this merits more work.  Larger animal models will need to be examined, and also it would be nice to know if administration of exosomes from mesenchymal stem cells can elicit a similar biological response.  However his is a very hopeful beginning to what might become a fruitful bit of clinical research.

Genetically Engineered Bone Marrow Stem Cells Reverse Ischemic Cardiomyopathy

Muhammad Ashraf is a professor of Pharmacology at the University of Illinois in Chicago.  Dr. Ashraf and his colleagues have published some very fine papers that have examined the ability of stem cells to heal the heart after a heart attack.  Recently, Ashraf’s team examined the ability of a particular population of bone marrow cells, characterized by the presence of the Sca-1 protein on their cell surfaces, to heal the heart after a heart attack.  In particular, Ashraf’s group genetically engineered Sca-1-positive cells to secrete a cocktail of growth factors, and then they tested the ability of such cells to heal a damaged heart.

Sca-1 is a protein that is found on the surfaces of hematopoietic stem cells and other cell types as well.  Therefore, selecting Sca-1 cells will not necessarily give you a pure cell population.  However, such cells can be readily isolated and genetically engineered to make these growth factors.

Ashraf and his coworkers isolated Sca-1 cells from the bone marrow of mice that expressed a glowing green protein.  These cells were then genetically engineered with plasmids (small circles of DNA) to express the growth factors Insulin-like growth factor-1, vascular endothelial growth factor, hepatocyte growth factor, and stromal cell-derived factor-1alpha.  All four of these growth factors have been shown to play supportive roles in the healing of the heart after a heart attack.

When these genetically engineered Sca-1-positive cells were co-cultured with other cells and then grown in low oxygen conditions, the genetically engineered cells prevented the other cells from dying.  The genetically engineered cells are grew faster in culture than their non-genetically engineered counterparts.  When the culture medium in which these genetically engineered cells were grown was used to grow umbilical vein endothelial cells (UVECs), those UVECs showed increased rates of growth.  This suggests that the genetically-engineered Sca-1 cells secreted growth factors into their culture medium and these growth factors are the reason these cell grow faster than non-genetically engineered Sca-1 cells.

When these same cells were injected into the heart tissue of mice that had suffered from heart attacks, they were able to survival over twice as well as non-genetically engineered Sca-1 cells.  When the laboratory animals that received the injections of genetically engineered Sca-1 cells were put down 4 weeks after their stem cell treatments, their hearts were removed, sectioned and examined in detail.  These examinations clearly showed that hearts from those mice that had received injections of genetically-engineered Sca-1 cells had increased blood vessel densities.  There was an additional surprise, since the injected Sca-1 cells were taken from green-glowing mice, they also glowed green.  Green-glowing cells were shown to express Cx43 (the protein that links heart muscle cells together and lets them beat in harmony) and be connected to host heart muscle cells.  This suggests that a bone marrow cell population can actually electrically connect with a heart muscle cell, which is something bone marrow cells are not supposed to be able to do.  Mind you, the number of connected cells was small, and they could be doing this simply as a result of cell fusion.

Additionally, injection of genetically-engineered Sca-1 cells also decreased the infarct size in the hearts of these mice.  The size of the infarct in the treated mice was less than half that of the untreated mice.

This shows that Sca-1 cells from bone marrow have the capacity to augment recovery of the heart after a heart attack, and that this ability is further increased through the co-administration of growth factors.  Using such a system in human patients will require the determination of the precise dosage of these growth factors, since using genetically engineered cells in human patients will probably not be approved in the near future.

How Cardiospheres Heal the Heart

In 2007, Eduardo Marbán and his colleagues have discovered a stem cell population from the hearts of mice and humans that grow as small balls of cells in culture (see RR Smith, et al., Circulation. 2007 Feb 20;115(7):896-908). He called these cells “cardiospheres” and in a follow-up study showed that these cells have the ability to differentiate into heart muscle cells, blood vessel cells, or other types of heart-specific cells (PV Johnson, et al., Circulation. 2009 Sep 22;120(12):1075-83). Other animal experiments by Marban’s group showed that not only were cardiospheres easily obtained by means of heart biopsies, but injection of these cells directly into the heart after a heart attack augmented healing of the heart and accelerated the recovery of heart function and while preserving heart structure (ST Lee, et al., J Am Coll Cardiol. 2011 Jan 25;57(4):455-65; CA Carr, et al., PLoS One. 2011;6(10):e25669; Shen D, Cheng K, Marbán E. J Cell Mol Med. 2012 Sep;16(9):2112-6).

All of these very hopeful results in culture and in animal studies eventually gave way to a small human clinical trial in which a heart patient’s own cardiospheres were transplanted into their own hearts.  This clinical trial, the CADUCEUS trial (which stands for cardiosphere-derived autologous stem cells to reverse ventricular dysfunction), prevent patient’s hearts from worsening, but more remarkably, the heart scars of these patients were partially erased 6 months after treatment.  A one-year follow-up showed that patients had improved global heart function that directly correlated to the shrinkage of their heart scars.

These results are very encouraging and Marbán made it clear that he wants to conduct larger clinical trials.  However, he still had a gaggle of unanswered questions about his cardiospheres.  Do these cells affect blood vessel formation?  Can they prevent the enlargement of the heart that occurs after a heart attack (known as cardiac remodeling)?  Can the benefits of these cells be solely linked to their effects on the heart scar?  Do cardiospheres prevent the formation of the heart scar?  Do they only help heal the area of the heart where they are administered or do they also help more far-flung regions of the heart?  These are all good questions, and answers to them are necessary if Marbán and his group is to conduct larger and more intense clinical trials with human heart patients.  Therefore, he turned to an animal model system to address these questions in detail.  In particular, he chose Wistar Kyoto rats.

Readers of this blog will recognize the experimental strategy; break the rats into three groups, induce experimental heart attacks in two groups, give one group cultured cardiospheres and leave the other one alone.  Thus you have a sham group that underwent surgery but was not given a heart attack, a heart attack group that did not receive cardiospheres, and a heart attack group into which 2 million rat cardiospheres were injected at four different sites near the site of the infarct.

This experiment, did far more than simply monitor the heart function of the animals for several weeks.  Instead, some of these animals were sacrificed and their hearts were subjected to extensive biochemical and molecular biological tests.   The goal of these experiments was to determine not just if the cardiospheres helped heal the heart.  Marbán and his group already knew that they do.  They wanted to know how they heal the heart.

The cardiosphere-treated animals showed substantial improvements in their heart function as opposed to their non-treated counterparts.  The treated animals had heart that did not undergo remodeling and also pumped better.  Hearts from the cardiosphere-treated animals had less dead heart tissue and more live tissue.  They had smaller heart scars, and better preservation of cellular structure in the heart.  When biochemical markers of proliferating cells were measured in these hearts, the cardiosphere-treated hearts showed robust increases in cell proliferation far above those hearts that were not treated with cardiospheres.  Thus cardiospheres seem to induce resident heart cells to divide and replace dead and dying heart cells.

A common response to a heart attack is that the surviving heart cells enlarge (hypertrophy).  The cardiosphere-treated hearts showed no such response.  Also, when the blood vessel density of the heart tissue was determined, the cardiosphere-treated hearts had close the twice the vessel density of the non-treated hearts.  This was the case near the site of cardiosphere injection, but it also held, albeit not as robustly, in areas far from the site of cardiosphere injection.  This suggests that blood vessel formation is due to secreted molecules.

To test this possibility, Marbán and his crew rigged a culture assay in which rings of tissue from the aorta (the largest blood vessel in the body), were embedded in collagen and treated with culture media from cardiospheres, standard culture cell culture media, or cell culture medium from endothelial cells.  The cardiosphere culture medium, which contains a cocktail of molecules secreted by growing cardiospheres as they have grown in culture, induced far more blood vessels in this system than the other two.  This confirms the notion that cardiospheres secrete blood vessels-inducing molecules that this increases the vascularization of the heart muscle, this aiding its survival.

Marbán and his team also examined the molecule that forms the heart scar; collagen and how cardiospheres affect the synthesis and deposition of collagen.  They discovered that cardiospheres actually degrade the collagen at the heart scar.  They showed that cardiosphere secrete enzymes that have been documented to degrade collagen (Matrix Metalloproteases 2 and 13 for those who are interested).  Marbán and others also discovered that cardiospheres put the kibosh on collagen synthesis.  When they measured biochemical markers of collagen synthesis (hydroxyproline), they were present at rather low levels.  Thus cardiospheres prevent the deposition of the heart scar and also actively degrade it.

Thus, Marbán and his colleagues showed that cardiospheres: 1) prevent the tissue-level changes associated with cardiac remodeling; 2) preserve heart function locally and globally; 3) increase the proliferation of heart muscle cells at the site of the infarct, and to a lesser effect, throughout the heart; 4) induce the formation of new blood vessels at the site of injection, and, to a lesser extend, further from the site of cardiosphere injection; and 5) actively prevent the formation of the heart scar by inhibiting its formation and degrading whatever collagen has been deposited.

Thus cardiospheres decrease the formation of collagen and therefore, decrease the stiffness of the wall of the heart.  They also product new blood vessels and provide a supportive environment for the formation of new heart muscle cells.

This paper was published in PLoS One (2014) 9(2):e88590.

May Marbán’s clinical trials increase!!

Preventing the Onset of Type 1 Diabetes

Diabetes researchers at Saint Louis University have discovered a way to prevent the onset of Type I diabetes mellitus in diabetic mice. This strategy involves inhibiting the autoimmune processes that result in the destruction of the insulin-secreting pancreatic beta cells.

Type I diabetes is a life-long disease that results from insufficient production of the vital anabolic hormone insulin. In most cases of Type I diabetes mellitus, the body’s immune system destroys insulin-producing beta cells, and this insulin deficiency causes high blood sugar levels, also known as hyperglycemia. Treatments for the disease require daily injections of insulin.

Dr. Thomas Burris, chair of the university’s pharmacological and physiological science department, and his colleagues, have published their results in the journal Endocrinology. IN this paper, they report a procedure that could potentially prevent the onset of the disease rather than just treating the symptoms

“None of the animals on the treatment developed diabetes even when we started treatment after significant beta cell damage had already occurred,” Burris explained in a prepared statement. “We believe this type of treatment would slow the progression of type I diabetes in people or potentially even eliminate the need for insulin therapy.”

A group of immune cells known as lymphocytes come in two main forms: B lymphocytes, which secrete the antibodies that bind to foreign cells and neutralize them, and T cells, which recognize foreign substances and regulate the immune response. There are several different types of T lymphocytes, but for the purposes of this discussion, two specific subtypes of T lymphocytes seem to be responsible for the onset of Type I diabetes. T “helper cells” that have the CD4 protein on their surfaces, and T “cytotoxic “ cells have the CD8 protein on their cell surfaces seem to play a role in the onset of Type I diabetes, but a third subtype of T lymphocyte has remained a bit of an enigma for some time. This subtype of T lymphocytes is a subcategory of CD4 T cells and secretes a protein called “interleukin 17,” and is, therefore, known as TH17.

Dr. Burris and his collaborators from the Department of Molecular Therapeutics at the Scripps Research Institute have been examining TH17 cells for some time and they came upon a pair of nuclear receptors that play a crucial role in the development of TH17 cells. Could hamstringing the maturation of TH17 cells delay the onset of Type 1 diabetes mellitus?

Burris and others targeted these receptors by using drugs that bound to them and prevented them from working. This prevented the maturation of the TH17 T lymphocytes. When two nuclear receptors, Retinoid-related orphan receptors alpha (ROR-alpha) and Gamma-t (ROR-gamma-t) were inhibited, they prevented the autoimmune response that destroyed the beta cells.

To block these ROR alpha and gamma t receptors, Burris and others used a selective ROR alpha inhibitor and a gamma t inverse agonist called SR1001 that was developed by Dr. Burris. These drugs significantly reduced diabetes in the mice that were treated with it.

These findings show that TH17 cells play a significant role in the onset of Type I diabetes, and suggest that the use of drugs like these that target this cell type may offer a new treatment for the illness.

According to the American Diabetes Association, only 5% of people with diabetes have the Type I form of the disease, which was previously known as juvenile diabetes because it is usually diagnosed in children and young adults. The organization said that over one-third of all research they conduct is dedicated to projects relevant to type 1 diabetes.

Rare Stem Cell Heals Damaged Lungs; Notch Signaling May Hold the Key to Lung Fibrosis

Patients who survive an acute lung injury are able to recover their lung function, which suggests that adult lungs regenerate to a certain extent. Depending on the cause and severity of the injury, multiple progenitor cells, including alveolar type II cells and distal airway stem cells, have been shown to drive lung tissue regeneration in mice. Now, Andrew Vaughan and others have described another cell type in the lungs involved in the repair process in mice when mouse lungs are damaged from influenza virus infection or inhalation of the anticancer drug bleomycin.  This cell type is called the rare lineage-negative epithelial progenitor (LNEP).

LNEP cells are quiescently present within normal distal mouse lung and do not express mature lineage markers (for example, a protein called club cell 10 or CC10 or surfactant protein C, otherwise known as SPC).  However, Vaughan and others demonstrate that LNEPs are activated to proliferate and migrate to damaged sites and mediate lung remodeling following major injury.

Vaughan and others used lineage tracing approaches and cell transplantation strategies and showed that LNEP cells, but not mature epithelial lineage cells, are multipotent in their ability to give rise to both club cells and alveolar cells.  Interestingly, activation of the Notch signaling pathway in LNEP cells initially activated them, but persistent Notch activation inhibited subsequent alveolar differentiation, resulting in failed tissue regeneration (characterized by the formation of abnormal honeycomb cysts in the mouse lung).  Thus Notch signaling is only required at the beginning of their activation, and then must be down-regulated if the LNEP cells are to reconstruct normal lung tissue.  Interestingly, scarred over or fibrotic lungs from patients with idiopathic pulmonary fibrosis or a disease called scleroderma show evidence of hyperactive Notch signaling and their lungs also contain very similar-looking honeycomb cysts.  This strongly suggests that dynamic Notch signaling also regulates the function and differentiation of LNEP-analogous human lung progenitor cells.  Thus designing treatments that properly regulate Notch signaling and, consequently, LNEP activity may potentially halt the development of lung fibrosis in humans.

A Way to Get Stem Cells to Make Living Heart Valve Tissue?

What a benefit it would be to be able to replace diseased and defective heart valves with new heart valves. Thus, living tissue engineered heart valves (TEHV) would be a boon to children who require replacement heart valves that have the capacity to grow with the child and completely integrate into the child’s heart tissue. A persistent challenge for TEHV is accessible human cell source(s) that have the ability to mimic native valve cell phenotypes and possess matrix remodeling characteristics that are essential for long-term function.

Mesenchymal stem cells derived from bone marrow (BMMSC) or adipose tissue (ADMSC) are intriguing cell sources for TEHV. Unfortunately, they have not been compared to pediatric human aortic valve interstitial cells (pHAVIC) in relevant 3-dimensional culture environments.

In a recent study, Bin Duan from the Biomedical Engineering department at Cornell University compared the spontaneous and induced multipotency of ADMSC and BMMSC to that of pHAVIC using different induction culture systems within three-dimensional (3D) bioactive hybrid hydrogels that have similar material properties to those of aortic heart valve leaflets. pHAVICs possessed some multi-lineage differentiation capacity in response to induction media, but these cells were limited to the earliest stages and their differentiation capacity were less potent than either ADMSCs or BMMSCs. ADMSCs expressed cell phenotype markers that were similar to pHAVICs when they were grown in HAVIC growth media spiked with a growth factor called basic fibroblast growth factor (bFGF). BMMSCs generally expressed extra cellular matrix remodeling characteristics similar to pHAVICs.

Duan and his colleagues then chemically attached bFGF to components of the 3D hybrid hydrogels in order to further immobilize them. The immobilized bFGF upregulated vimentin expression and promoted the fibroblastic differentiation of pHAVIC, ADMSC and BMMSC. Since fibroblasts help make heart valves, these changes in gene expression might presage the ability of these cells to form new heart living heart valve tissue.

Thus, these findings show that even though mesenchymal stem cells retain a heightened capacity to form bone in 3D culture, this tendency can be shifted fibroblast cell fates by tethering bFGF to the 3-D matrix. Such a strategy is probably rather important for utilizing stem cell sources in heart valve tissue engineering applications.

This is an important finding.  Even though the production of TEHVs are some ways off, Duan’s findings might provide a strategy to begin cells on the path to making TEHVs.

Do Human Mesenchymal Stem Cell Therapies Help Older Patients with Ischemic Cardiomyopathy?

Joshua Hare from the Interdisciplinary Stem Cell Institute at the University of Miami Miller School of Medicine in Miami, Florida has conducted a variety of high-quality clinical trials that have tested the ability of mesenchymal stem cells to heal the hearts of patients with ischemic heart disease. Two of these trials, (Transendocardial Autologous Cells in Ischemic Heart Failure) and POSEIDON (Percutaneous Stem Cell Injection Delivery Effects on Neomyogenesis), injected mesenchymal stem cells from bone marrow directly into damaged heart muscle.

Both of these studies not only showed an increase in heart function after injection of mesenchymal stem cells compared to placebo, but further examination showed that mesenchymal stem cells induced shrinkage of the heart scar and replacement with living heart muscle tissue (see Alan Heldman and others, Transendocardial Mesenchymal Stem Cells and Mononuclear Bone Marrow Cells for Ischemic Cardiomyopathy: The TAC-HFT Randomized Trial, JAMA, Published online November 18th 2013). However, Hare wanted to compare the benefits experienced by younger patients with older patients in order to determine if age had any effect on the efficacy of this treatment.

To that end, Hare and his colleagues compared subjects from the TAC-HFT and POSEIDON clinical trials in 2 age groups: younger than 60 and 60 years of age and older. They used a 6-min walk distance to measure heart function and the Minnesota Living With Heart Failure Questionnaire (MLHFQ) to ascertain the quality of life of each patient.  Patients were tested at baseline (before the procedure), 6 months, and 1 year after the procedure.  Hare and his group also used particular cardiac imaging measurements, such as absolute scar size and compared the baseline size of the heart scar, and then again 1 year after the procedure.

These two tests, the 6MWD and the MLHFQ showed improvements in both age groups. These improvements were even significant in both groups. What this analyses show is that mesenchymal stem cell therapy helps patients with ischemic heart failure, regardless of their age. Older individuals did not have an impaired response to MSC therapy.

This is an important result because heart disease is very often a condition of the aged and there are concerns as to whether or not older patients would benefit from regenerative medical procedures. Hare’s study suggests that older patients do benefit from these procedures. A caveat is that older patients have lower-quality mesenchymal stem cells, but these studies tended to use allogeneic mesenchymal stem cells or stem cells from donors. Therefore, allogeneic stem cell treatments may prove effective in older heart patients.

Gestational Diabetes Affects the Quality of Umbilical Cord Mesenchymal Stromal Cells

The laboratories of Drs. Jene Choi and Chong Jai Kim from the University of Ulsan College of Medicine in Seoul, South Korea have collaboratively shown that the therapeutic quality of umbilical cord mesenchymal stem cells is profoundly affected by gestational diabetes. Their work was published in a recent issue of the journal Stem Cells and Development and has profound implications for regenerative medicine.

Choi and Kim and their coworkers collected umbilical cords from mothers who had been given birth by Cesarian section and had also been diagnosed with gestational diabetes and mothers who had also just given birth by Cesarian section and showed normal blood sugar control. These umbilical cord tissues were processed and the mesenchymal stem cells from the cord tissue were isolated and cultured. These cells were grown and then subjected to a rather extensive battery of tests. These tests were a reflection of the ability of these to perform in regenerative treatments.

First umbilical cord mesenchymal stem cells (UCMSCs) from mothers with gestational diabetes (GD) did not grow as well as UCMSCs from mother who did not have GD.  As you can see in the graphs below, these are not small growth differences.  The UCMSCs from non-GD mothers (on the left) grow substantially better than those from GD mothers.  This result is also consistent for different cell lines.  This also means that transplanted cells would not grow very well if they were used for therapeutic purposes.

Umbilical cord mesenchymal stromal cells (UC-MSCs) derived from gestational diabetes mellitus (GDM) patients exhibit retarded growth proliferation. The growth of 7.5×103 UC-MSCs isolated from patients with normal pregnancies (A) and GDM (B) was monitored over a period of 12 days. GDM-UC-MSCs consistently showed decreased proliferation compared with normal pregnant women (N-UC-MSCs). Points represent the mean values from three independent experiments; bars denote standard deviation (SD).
Umbilical cord mesenchymal stromal cells (UC-MSCs) derived from gestational diabetes mellitus (GDM) patients exhibit retarded growth proliferation. The growth of 7.5×103 UC-MSCs isolated from patients with normal pregnancies (A) and GDM (B) was monitored over a period of 12 days. GDM-UC-MSCs consistently showed decreased proliferation compared with normal pregnant women (N-UC-MSCs). Points represent the mean values from three independent experiments; bars denote standard deviation (SD).

Secondly, UCMSCs from GD mothers showed a greater tendency to undergo premature senescence.  When MSCs are grown in culture, they usually grow rather well for several days and then the cells go to sleep and they stop growing.  This is called culture senescence and it is due to intrinsic properties of the cells.  When the cells go into senescence tends to be a cell line-specific property, but one thing is certain; the sooner cells become senescent, the few cells they will generate in culture.  The UCMSCs from GD mothers go into senescence early and easily and this is one of the reasons they grow so poorly relative to normal cells – because they are running to their beds to take a nap (so to speak).  Such cells are usually not good candidates for regenerative medicine.

Third, UCMSCs from GD mothers show poor lineage-specific differentiation.  MSCs have the ability to differentiate into fat cells, bone cells, and cartilage cells if particular well-established protocols are used.  However, UCMSCs from GD mothers showed inefficient differentiation and that is one of the things that MSCs must do if they are to repair bone or cartilage problems or if they are to help make smooth muscle for new blood vessels formation. 

Stem cell differentiation potentials are largely different between normal and GDM-affected UC-MSCs. Three different cell lines of normal and GDM-affected pregnancies were cultured in a control medium or induction medium for 5 days. Upregulation of the expression of the adipogenic-specific gene PPARγ (A) and the osteogenic genes alkaline phosphatase (ALP) (B), osteocalcin (OC) (C), and collagen type 1 alpha 1 (Col1α1) (D) was evaluated by real-time RT-PCR and normalized to GAPDH. All assays were performed in triplicate; bars denote SD (*P<0.05).
Stem cell differentiation potentials are largely different between normal and GDM-affected UC-MSCs. Three different cell lines of normal and GDM-affected pregnancies were cultured in a control medium or induction medium for 5 days. Upregulation of the expression of the adipogenic-specific gene PPARγ (A) and the osteogenic genes alkaline phosphatase (ALP) (B), osteocalcin (OC) (C), and collagen type 1 alpha 1 (Col1α1) (D) was evaluated by real-time RT-PCR and normalized to GAPDH. All assays were performed in triplicate; bars denote SD (*P<0.05).

The figure above shows the disparity between these established UCMSC cell lines.  The dark, solid bars indicate non-induced cells that were grown in normal culture media, and the striped bars are cells grown in media that designed to induce the differentiation of these cells into either bone, fat, or cartilage cells.  The cell lines with “N” in their name are from non-GD mothers and those with “D” in their designations are from GD mothers.  These assays are for genes known to be strongly induced when cells begin to differentiate into fat (PPARgamma), bone (ALP or osteocalcin or collagen 1 alpha 1).  As you can clearly see, the Ns outdo the Ds every time.

Finally, when the mitochondria, the compartments in cells that generate energy, from these two cell populations were examined it was exceedingly clear that UCMSCs from GD mothers had mitochondria that were abnormal and did not make every very well.  Mitochondria from UCMSCs taken from GD mothers showed decreased expression of the energy-making components.  Thus the energy-making pathways in these cell compartments were sub-par from a structural perspective.  Functional assays for mitochondria showed that mitochondria from UCMSCs from GD mothers consistently underperformed those from UCMSCs taken from non-GD mothers.  Also, when markers of mitochondrial dysfunction were measured (reactive oxygen species and indicators of mitochondrial damage from reactive oxygen species), such markers were consistently higher in mitochondria from UCMSCs from GD mothers relative to those from non-GD mothers.  This shows that the energy-making or powerhouses of the cells are dysfunctional in UCMSCs from GD mothers.  Without the ability to properly make energy from food molecules, the cells have a diminished capacity to heal damaged tissues and organs.

Several studies have established a positive link between mitochondrial dysfunction and accelerated aging.  Therefore, these cells, because they have more extensive indications of mitochondrial damage, may show profound accumulation of mitochondrial damage and accelerated aging.

In summary, this study shows that integral biological properties of human UC-MSCs differ according to obstetrical conditions.  These data also stress the importance of maternal–fetal conditions in biological studies of hUC-MSCs and the development of future therapeutic strategies using hUC-MSCs.

Stem Cells from Adult Nose Tissue Used to Cure Parkinson’s Disease in Rats

For the first time, German stem cell scientists from the University of Bielefeld and Dresden University of Technology have used adult human stem cells to “cure” rats with Parkinson’s disease.

Parkinson’s disease results from the death of dopamine-using neurons in the midbrain, and the death of these midbrain-based, dopamine-using neurons causes a loss of control of voluntary motion. Presently, no cure exists for Parkinson disease.

In this study, which was published in STEM CELLS Translational Medicine, the German team produced mature dopamine-using neurons from inferior turbinate stem cells (ITSCs). ITSCs are stem cells taken from tissues that are normally discarded after an adult patient undergoes sinus surgery. The German team tested how ITSCs would behave when transplanted into a group of rats with a chemically-induced form of Parkinson’s disease. Prior to transplantation, the animals showed severe motor and behavioral abnormalities. However, 12 weeks after transplantation of the ITSCs, the cells had not only migrated into the animals’ brains, but their functional ability was fully restored and significant behavioral recovery was also observed. Additionally, none of the treated animals shows any signs of tumors after the transplantations, something that also has been a concern in stem cell therapy.

“Due to their easy accessibility and the resulting possibility of an autologous transplantation approach, ITSCs represent a promising cell source for regenerative medicine,” said UB’s Barbara Kaltschmidt, Ph.D., who led the study along with Alexander Storch, M.D., and Christiana Ossig, M.D., both of Dresden University. “The lack of ethical concerns associated with human embryonic stem cells is a plus, too.”

“In contrast to fighting the symptoms of Parkinson’s disease with medications and devices, this research is focused on restoring the dopamine-producing brain cells that are lost during the disease,” said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and director of the Wake Forest Institute for Regenerative Medicine. These cells are easy to access and isolate from nasal tissue, even in older patients, which adds to their attraction as a potential therapeutic tool.”

This is certainly a very exciting animal study, but treating chemically-induced Parkinson’s disease in rodents and treating Parkinson’s disease in aged human patients is two very different things. Thus while this study is important, work in human wild require more testing and studies in larger animals.

Novastem Treats Its First Stroke Patient With Stemedica’s Mesenchymal and Neural Stem Cell Combination

The biotech company Novastem is a leader in regenerative medicine and has announced the treatment of its first patient in its clinical study for ischemic stroke at Clinica Santa Clarita, Mexico. This clinical trial is testing cell products made by Stemedica. In particular, Stemedica’s ischemia-tolerant mesenchymal stem cells (itMSCs) were administered in combination with ischemia-tolerant neural stem cells (itNSCs); both of which are proprietary products of Stemedica.

Stemedica‘s itMSCs and itNSCs are unique because of the manner in which they are manufactured – they are grown under conditions that make them resistant to low-oxygen conditions. Experiments conducted with these cells in culture and in living animals have definitely shown that when these cells are exposed to low-oxygen conditions, they show greater homing and engraftment than cells grown under normal conditions. Compared to other MSCs and NSCs, Stemedica’s stem cells secrete higher levels of growth factors and other important proteins associated with angiogenesis and healing.

According to the American Stroke Association, ischemic strokes account for 87 percent of all stroke cases. Novastem is continuing to enroll qualified patients in their study. This clinical trial is entitled “Internal Research Protocol in Combination Therapy of Intravenous Administration of Allogeneic Mesenchymal Stem Cells and Intrathecal Administration of Neural Stem Cells in Patients with Motor Aphasia due to Ischemic Stroke.” All participants in this clinical trial will receive a unique, combination stem cell therapy consisting of cells made by Stemedica Cell Technologies.

Novastem is sponsoring this clinical trial and Novastem is the only company licensed to use Stemedica’s stem cell products for studies in Mexico. Novastem’s Clinica Santa Clarita facility is federally licensed to use stem cell therapies, and this trial marks the first time ischemic stroke is being treated with a patented medical method that comprises administration of hypoxically-grown neural stem cells into the cerebrospinal fluid in combination with intravenous administration of hypoxically-grown mesenchymal stem cells. This combination approach is designed to treat the after effects of ischemic strokes.

“Novastem and Clinica Santa Clarita are committed to advancing the research of neurodegenerative disease, and we are pleased to be working with internationally-recognized physician Clemente Humberto Zuniga Gil, MD as the principal investigator and study designer,” says Rafael Carrillo, Novastem’s President. “Our medical team believes that Stemedica’s mesenchymal and neural stem cells, used in this unique combination therapy, will restore and build new vascularization, improve the blood supply, reconnect damaged neural networks and improve functionality of areas affected by our patients’ ischemic stroke.”

The aim of this Novastem study is to evaluate functional changes on subjects after the administration of ischemia-tolerant mesenchymal and neural stem cells. The protocol in use in this clinical trial has been approved by the Research Ethics Committee of Clinica Santa Clarita, which is federally registered and licensed by the Federal Commission for the Protection against Sanitary Risk (COFEPRIS), a division of Mexico’s Ministry of Health.

Patient progress will be tracked at the beginning of the study before any cells have been administered, at 90 days after stem cell administration, and then again at 180 days after administration. Patient improvement will be ascertained with the United States National Institute of Health Stroke Score (NIHSS), Stroke and Aphasia Quality of Life Scale-39 (SAQCOL-39) and the Boston Diagnostic Aphasia Examination (BDAE) neuropsychological evaluation for diagnosis. Additionally, MRIs taken with a gadolinium-based contrast agent (GBCA) will examine the structural integrity of the brain before and after stem cell administration. At the endpoint, the treatment will be evaluated for safety and tolerance of the two-cell treatment. Additionally, patients will be evaluated for changes in neurological functionality.

New Bone Marrow-Based Stem Cell Identified in Mice that Regenerates Bones and Cartilage in Adults

Researchers at Columbia University Medical Center (CUMC) have discovered a bone marrow-based stem cell capable of regenerating both bone and cartilage in mice. The discovery appeared in the online issue of the journal Cell.

These cells have been called osteochondroreticular (OCR) stem cells, and they were identified in experiments that tracked a protein expressed by these cells. By using this specific protein as a marker for OCR stem cells, the Columbia team found that OCR cells self-renew and produce key bone and cartilage cells, including osteoblasts and chondrocytes. Furthermore, when OCR stem cells are transplanted to a fracture site, they dutifully contribute to bone repair.

“We are now trying to figure out whether we can persuade these cells to specifically regenerate after injury. If you make a fracture in the mouse, these cells will come alive again, generate both bone and cartilage in the mouse—and repair the fracture. The question is, could this happen in humans,” says Siddhartha Mukherjee, MD, PhD, assistant professor of medicine at CUMC and a senior author of the study.

Since mice and humans have similar bone biology, Mukherjee and his colleagues are quite confident that OCR stem cells exist in human bone marrow. Further studies could uncover new and effective ways to exploit OCR cells to provide greater ways to prevent and treat osteoporosis, osteoarthritis, or bone fractures.

“Our findings raise the possibility that drugs or other therapies can be developed to stimulate the production of OCR stem cells and improve the body’s ability to repair bone injury—a process that declines significantly in old age,” says Timothy C. Wang, MD, the Dorothy L. and Daniel H. Silberberg Professor of Medicine at CUMC, who initiated this research. Wang and his team previously found an analogous stem cell in the intestinal tract and observed that it was also abundant in the bone.

“These cells are particularly active during development, but they also increase in number in adulthood after bone injury,” says Gerard Karsenty, MD, PhD, the Paul A. Marks Professor of Genetics and Development, chair of the Department of Genetics & Development, and a member of the research team.

Mukherjee and his coworkers also showed that adult OCR stem cells are distinct from mesenchymal stem cells (MSCs). MSCs play essential roles in bone generation during development and adulthood. Therefore, researchers thought that MSCs gave rise to all bone, cartilage, and fat, but recent studies have shown that MSCs do not generate young bone and cartilage. This study by Mukherjee and his colleagues suggests that OCR stem cells actually make young bone and cartilage, but both OCR stems cells and MSCs contribute to bone maintenance and repair in adults.

Mukherjee also suspects that OCR cells may play a role in soft tissue cancers.

A research team from Stanford University School of Medicine just released a similar study that used a different methodology to identify the same stem cell type.

Brigham and Women’s Hospital Researchers Reverse Type 1 Diabetes in Diabetic Mice

Brigham and Women’s Hospital (BWH) is a Harvard University-affiliated institution with a robust research program. In particular, several BWH are interested in mesenchymal stem cells and their ability to suppress inflammation and mediate healing in injured organs.

To that end, a research team led by Robert Sackstein from BWH’s Departments of Dermatology and of Medicine and Reza Abdi from BWH’s Department of Medicine and Transplantation Research Center, has published a stupendous report in the journal Stem Cells. In this paper, Sackstein and his coworkers used mesenchymal stem cells (MSCs) to successfully treat laboratory animals that suffered from type 1 diabetes.

Type 1 diabetes is, to a large extent, a disease of the immune system, since a large majority of type 1 diabetes patients have immune cells that recognize the insulin-secreting beta cells as foreign and these immune cells attack and obliterate them. MSCs are a type of adult stem cell that has shown potent immune-suppressing and anti-inflammatory effects in animal and human clinical studies. Previous preclinical trials with diabetic-prone mice have demonstrated that intravenous administration of MSCs can tamp down pancreatic injury and reduce the blood sugar levels without insulin administration. However, these effects were modest and temporary.

Sackstein and his team suggested that if more MSCs could be inserted into the pancreatic islets, then more islets would be spared from immune destruction. This would yield a more complete reversal of diabetes.

MSCs tend to lack a key cell surface adhesion molecule called HCELL. HCELL mediates the homing of cells in the bloodstream to inflammatory sites. Unfortunately, direct injection of MSCs directly into pancreatic islets is not clinically feasible because the pancreas is fragile and the damage caused by injection would cause the release of hydrolytic enzymes that would degrade the rest of the pancreas and other tissues as well. In order to move intravenously administered MSCs to the sites of the immune attack, Sackstein and others engineered MSCs that expressed the HCELL homing molecule. The presence of HCELL on the surfaces of these MSCs directed them to the inflamed pancreatic islets.

The BWH team found that administering these HCELL-bearing MSCs into diabetic mice caused the MSCs to lodge in the islets. These cells decreased inflammation in the pancreas and durably normalized blood sugar levels in the mice, which eliminated the need for insulin administration; in other words they caused a sustained reversal of diabetes

Sackstein concluded that while further studies of the effects of MSCs are warranted, this preclinical study represents an important step in the potential use of mesenchymal stem cells in the treatment of type 1 diabetes and other immune-related diseases.

Embryonic Stem Cell Contamination Responsible for STAP Research Snafu

STAP or stimulus-triggered acquisition of pluripotency cells were allegedly derived from mature, adult cells by simply subjecting those cells to environmental stresses. These environmental stresses, such as low pH treatments and so on, were thought to cause cells to express genes that pushed them into an embryonic stem cell-like state. Researchers from the RIKEN institute reported these reports in the prestigious international journal Nature, and these advances were hailed as a stupendous advancement in stem cell biology.

However, as soon as stem cell scientists tried to repeat the results from these papers and failed, trouble started. Major laboratories had no success in recapitulating the results in the RIKEN institute papers, and, on-line post-publication reviews noticed some nagging problems in the published papers. RIKEN institute launched an investigation into the matter, and concluded that the lead researcher in these papers was guilty of scientific misconduct.

Now, new work as suggested that the whole thing was the result of contamination of the RIKEN group cells with embryonic stem cells. How that contamination occurred, however, remains unknown.

The RIKEN institute investigation was instigated by the institute and was carried out by a committee composed of seven outsiders. The committee analyzed DNA samples and laboratory records from two research teams who had participated in the STAP cell research. Those Nature papers have been retracted, but were once thought to provide a shortcut to producing pluripotent stem cells. The latest investigation suggests that the STAP findings resulted from contamination by embryonic stem cells. The investigation found signs of three separate embryonic stem cell lines, and they noted that it is difficult to imagine how contamination by three distinct lines could be accidental, but that they could also not be certain that it was intentional.

“We cannot, therefore, conclude that there was research misconduct in this instance,” the committee wrote. It did, however, find evidence that lead investigator Haruko Obokata, the lead author of the STAP papers, who formerly worked at the RIKEN Center for Developmental Biology in Kobe, Japan, had fabricated data for two figures in the original STAP publications.

Children’s Hospital Los Angeles Researchers Grow Functional Tissue-Engineered Intestine from Human Cells

Children’s Hospital Los Angeles is the home of a remarkable new study that has succeeded in growing tissue-engineered small intestine from human cells. This tissue engineered intestine recapitulates several key functional characteristics of human intestine such as the ability to absorb sugars. It also has structural features of human small intestine, such as a mucosal lining, support structures tiny and ultra-structural components like cellular connections.

This work was published in the American Journal of Physiology; GI and Liver and brings surgeons one step closer to using tissue engineered intestines in human patients.

Tissue-engineered small intestines are grown from stem cells isolated from the intestine. These laboratory-grown tissues offer a promising treatment for clinical conditions such as short-bowel syndrome (SBS), which is a major cause of intestinal failure, particularly in premature babies and newborns with congenital intestinal anomalies. Tissue engineered small intestines may also, perhaps in the future, offer a therapeutic alternative to intestinal transplantations, which is fraught with the problems of donor shortage and the need for lifelong immunosuppression.

Senior author Dr. Tracy Grikscheit, who is a principal investigator at the Saban Research Institute, which is housed at the Children’s Hospital of Los Angeles (CHLA), and the Developmental Biology and Regenerative Medicine program at the Children’s Hospital of Los Angeles. Dr. Grikscheit is also a pediatric surgeon at CHLA and assistant professor of surgery at the Keck School of Medicine of the University of Southern California.

Grikscheit main interest, as a clinician, is to find strategies to treat the most vulnerable young patients. For example, babies who are born prematurely can sometimes develop a devastating disease called necrotizing enterocolitis (NEC), in which life-threatening intestinal damage demands that large portions of the small intestine be surgically removed. Without a long enough intestine, NEC babies are dependent on intravenous feeding. This intravenous feeding is costly and may cause liver damage. NEC and other contributors to intestinal failure occur in 24.5 out of 100,000 live births, and the incidence of SBS is increasing and nearly a third of patients die within five years.

CHLA scientists had previously shown that tissue-engineered small intestine could be generated from human small intestine donor tissue implanted into immunocompromised mice. These initial studies were published in July 2011 in the biomedical journal Tissue Engineering, Part A, and while it was a hopeful study, only basic components of the intestine were identified in the implanted intestine. To be clinically relevant, it is necessary to make tissue engineered intestines that form a healthy barrier that can still absorb nutrition and regulate the exchange of electrolytes.

This new study, however, showed that mouse tissue engineered small intestines are quite similar to the tissue-engineered small intestines made from human intestinal stem cells. Both contain important building blocks such as the stem and progenitor cells that continue to regenerate the intestine throughout the lie of the organism. These cells are found within the engineered tissue in specific locations and are close to other specialized cells that are known to be necessary for the intestine to function as a fully functioning organ.

“We have shown that we can grow tissue-engineered small intestine that is more complex than other stem cell or progenitor cell models that are currently used to study intestinal regeneration and disease, and proven it to be fully functional as it develops from human cells,” said Grikscheit. “Demonstrating the functional capacity of this tissue-engineered intestine is a necessary milestone on our path toward one day helping patients with intestinal failure.”

Grafted Stem Cells Display Robust Growth in Spinal Cord Injury Model

University of San Diego neuroscientists have used an animal model of spinal cord injury to test the ability of engrafted stem cells to regenerate damaged nerves. Mark Tuszynski and his team built on earlier work with implanted neural stem cells and embryonic stem cell-derived neural stem cells in rodents that had suffered spinal cord injuries.

In this study, Tuszynski and others used induced pluripotent stem cells that were made from a 86-year-old male. This shows that skin cells, even from human patients who are rather elderly, have the ability to be reprogrammed into embryonic stem cell-like cells. These cells were differentiated into neural stem cells and then implanted into the spinal cords of spinal cord-injured rodents.

The injured spinal cord is a very hostile place for implanted cells. Inflammation in the spinal cord summons white blood cells to devour cell debris. White blood cells are rather messy eaters and they release enzymes and toxic molecules that can kill off nearby cells. Also, regenerating cells run into a barrier made by support cells called glial cells that inhibit regenerating neurons from regenerating. Thus, the injured spinal cord is quite the toxic waste dump.

To get over this, Tuszynski and his coworkers treated their induced pluripotent stem cell-derived neural stem cells with growth factors. In fact, when the cells were implanted into the animal spinal cords, they were embedded in a matrix that contained growth factors. After three months, Tuszynski and his colleagues observed extensive axonal growth projecting from grafted neurons that reached long distances in both directions along the spinal cord from the brain to the tail end of the spinal cord. These sprouted axons appeared to make connections with the existing rat neurons. Importantly, these axons extended from the site of the injury, which is astounding given that the injured area of the spinal cord has characteristics that are inimical to neuronal and axon growth.

Even though Tuszynski and others showed that neural stem cells made from embryonic stem cells can populate the damaged spinal cord, using induced pluripotent stem cell-derived neural stem cells has an inherent advantage since these cells are less likely to be rejected by the patient’s immune system. Furthermore, the induced pluripotent stem cell-derived neural stem cells showed dramatic growth in the damaged spinal cord, but the implanted animals did not regain the use of their forelimbs. The implanted human cells were fairly young when the implanted animals were tested. Therefore, they might need to mature before they could restore function to the implanted animals.

“There are several important considerations that future studies will address,” Tuszynski said. “These include whether the extensive number of human axons make correct or incorrect connections; whether the new connections contain the appropriate chemical neurotransmitters to form functional connections; whether connections once formed are permanent or transient; and exactly how long it takes human cells to become mature. These considerations will determine how viable a candidate these cells might before use in humans.”

Tuszynski and his group hope to identify the most promising neural stem cell type for repairing spinal cord injuries. Tuszynski emphasized their commitment to a careful, methodical approach:

“Ultimately, we can only translate our animal studies into reliable human treatments by testing different neural stem cell types, carefully analyzing the results, and improving the procedure. We are encouraged, but we continue to work hard to rationally to identify the optimal cell type and procedural methods that can be safely and effectively used for human clinical trials.”

Mesenchymal Stem Cell Transplantation Improves Atherosclerotic Lesions

Several animal studies have shown that transplantation of mesenchymal stem cells from several different sources is beneficial in myocardial infarction and hind limb ischemic. However, can these cells improved atherosclerosis, otherwise known as hardening of the arteries?

Shih-Chieh Hung and colleagues from National Yang-Ming University in Taipei, Taiwan tested this very hypothesis.

Hung and others used to lines of experimentation to address this question. First, they used cultured endothelial cells that had been treated with oxidized low-density lipoprotein particles. Secondly, they fed mice mutant for ApoE-deficient a high-fat diet.  ApoE-deficient humans and mice develop atherosclerotic plaques rather quickly.

In the cultured endothelial cells, oxidized LDL turned off the production of nitric oxide (NO). NO is a signaling molecule produced by several cell types, but in particular, endothelial cells use NO to dilate blood vessels. NO also is a good signal of endothelial health. Therefore, when oxidized LDL causes cultured endothelial to decrease NO production, it is affecting endothelial cell health. However, when cultured endothelial cells that had been treated with oxidized LDL were cocultured with mesenchymal stem cells, NO production and the enzymes that synthesize NO increased precipitously. Thus in a cultured system, MSCs have the ability to prevent the deleterious of oxidized LDL.

In ApoE-deficient mice fed a high fat diet, the arteries of the mice showed extensive plaque formation. However, if these animals were implanted with bone-marrow-derived mesenchymal stem cells, plaque formation was greatly decreased. Further work showed that a protein secreted by mesenchymal stem cells called macrophage inflammatory protein-2 (MIP-2) was responsible for these ameliorative effects. If MIP-2 was applied without mesenchymal stem cells, plaque formation was limited, and if antibodies that neutralize MIP-2 were co-administered with mesenchymal stem cells, the cells failed to reduced plaque formation.

Thus, this interesting study shows that transplantation of mesenchymal stem cells can limit plaque formation in atherosclerotic animals and they do this through secretion of MIP-2. Secondly, mesenchymal stem cells can improve the health of endothelial cells, which are the cells that form the inner layer of blood vessels, which are so adversely affected by atherosclerosis. By utilizing the encore of proteins secreted by mesenchymal stem cells, scientists should be able to develop a cocktail of proteins that can ameliorate atherosclerosis in human patients.

Safety and Feasibility of Epicardial Delivery of Umbilical Cord Blood-Derived Mononuclear Cells in a Porcine Model System

Most of the studies that have examined the effects of stem cell transplantation into the heart after a heart attack have only examined the effects of these cells for 4-6 weeks. There are very few long-term studies on the effects of implanted cells.

Fortunately, Timothy Nelson at the Mayo Clinic has published a long-term study of the effects of transplantation of umbilical cord mononuclear cells into the hearts of pigs. In this study, Nelson and his coworkers aimed to evaluate the feasibility and long-term safety of autologous umbilical cord blood mononuclear cells (UCB-MNCs) that were transplanted into the right ventricle (RV) of juvenile porcine hearts. The results are very encouraging.

In this study, piglets were born by means of Caesarean section in order to enable the collection of umbilical cord blood. 12 animals were assigned to either the placebo or test group, which half of them in one group and the other half in the other. 3 × 106 cells per kilogram were injected into the hearts of the test group and 10% DMSO were injected into the hearts of the placebo animals. These animals were monitored for 3 months after implantations, and the performance of their hearts was assessed in addition to biochemical markers, followed by terminal necropsy. None of the animals died as a result of these treatments.

The worse side effect of the surgeries was that two animals from the placebo group developed local skin infection after surgery that successfully responded to antibiotic treatment. Electrocardiograms (EKGs) of the treated animals showed no abnormalities in either group throughout the 3-month study. Two animals in the cell-therapy group had some issue right after surgery, but this is almost certainly a response to the anesthesia. Overall, this study demonstrated that autologous umbilical cord blood mononuclear cells can be safely collected and surgically delivered in a pediatric setting. The safety profile of these cells shows that they can be used to safely treat juvenile hearts. These studies should accelerate cell-based therapies to clinical trials for chronic heart disease.

Lung Stem Cells Heal Lungs and Point to Possible New Treatments

Frank McKeon, Ph.D., and Wa Xian, Ph.D. from Jackson Laboratory and their colleagues have identified the a certain lung stem cell, and the role it plays in regenerating lungs.

This work, which appeared in the Nov. 12 issue of the journal Nature, provides some much-needed clarification of the nuts and bolts of lung regeneration and provides a way forward for possible therapeutic strategies that harness these lung stem cells.

“The idea that the lung can regenerate has been slow to take hold in the biomedical research community,” McKeon says, “in part because of the steady decline that is seen in patients with severe lung diseases like chronic obstructive pulmonary disease (known as COPD) and pulmonary fibrosis.”

McKeon noted that there is ample evidence of a robust system for lung regeneration. “Some survivors of acute respiratory distress syndrome, or ARDS, for example, are able to recover near-normal lung function following significant destruction of lung tissue.”

This is a capacity that humans share with mice. Mice infected with the H1N1 influenza virus show progressive inflammation in the lung followed by the death and loss of important lung cell types. However, over the course of several weeks, the lungs of these mice recover and show no signs of previous lung injury.

Because of the presence of such robust lung regeneration in mice, these organisms provide a fine model system to study lung regeneration.

McKeon and his colleagues had previously identified a type of adult lung stem cell known as p63+/Krt5+ in the distal airways. When grown in culture, these p63+/Krt5+ lung stem cells neatly formed alveolar-like structures that were similar to those found within the lung. Alveoli are the tiny, specialized air sacs that form at the ends of the smallest airways, where gas exchange occurs in the lung. Following infection with H1N1, these same stem cells migrated to sites of inflammation in the lung and clustered together to form pod-like structures that resemble alveoli, both visually and molecularly.

McKeon and his colleagues reported that when the lung is damaged by H1N1 infraction, p63+/Krt5+ lung stem cells proliferate and contribute to the development of new alveoli near sites of lung inflammation.

To determine if these cells are required for lung regeneration, McKeon and his coworkers developed a novel system that utilizes genetic tools to selectively remove these cells from the mouse lung. Mice that lack p63+/Krt5+ lung stem cells cannot recover normally from H1N1 infection, and instead exhibit scarring of the lung and impaired oxygen exchange. This demonstrates the key role p63+/Krt5+ lung stem cells play in regenerating lung tissue.

To carry this work one step further, McKeon and his team isolated and subsequently transplanted p63+/Krt5+ lung stem cells into a damaged lung. The transplanted p63+/Krt5+ cells readily contribute to the formation of new alveoli, which nicely illustrates the capacity of these cells to regenerate damaged lung tissue.

In the U.S. about 200,000 people have Acute Respiratory Distress Syndrome, a disease with a death rate of 40 percent, and there are 12 million patients with COPD. “These patients have few therapeutic options today,” Xian says. “We hope that our research could lead to new ways to help them.”