Induced Pluripotent Stem Cell-Derived Kidney Progenitor Cells Heal Kidneys in Laboratory Animals

The kidney is a crucial organ for human survival and human flourishing. This organ filters metabolic wastes from the blood and if the kidney does not work, the body slowly poisons itself.

When the kidneys fail to work properly, they must be replaced by transplantation of a tissue-matched kidney from a donor. However, if the kidney is not completely damaged, then it might be possible to heal it by means of cell therapies. For example, if we could transplant renal progenitor cells into the kidney that then differentiate into kidney-specific tissues, then we could potentially replace damaged tissues in the kidney and help the kidney fully recover. The tough part of such a treatment strategy has been acquiring a sufficient number of kidney progenitor cells. However, scientists have considered using induced pluripotent stem cells (iPSCs), since these cells can be expanded in culture to very high numbers of cells that can be effectively differentiated into kidney progenitors.

Induced pluripotent stem cells are made from mature, adult cells by means of a combination of genetic engineering and cell culture techniques. These cells have the potency to differentiate into any cell type in the human body. Ideally, renal progenitors could be transplanted directly into the kidney parenchyma, but, again, this is not a simple-to-solve problem. “The kidney is a very solid organ, which makes it very difficult to bring enough number of cells upon transplantation,” explains Professor Kenji Osafune. Dr. Osafune’s laboratory is at the Center for iPS Cell Research and Application (CiRA) at Kyoto University, Japan, and is using iPSCs to investigate new treatments for kidney disease. Several studies have successfully transplanted adequate numbers of kidney progenitors to treat kidney disease.

In a new study, Dr. Osafune has collaborated with Astellas Pharma Inc., in order to potentially design a solution that can solve the problem of treating the kidney with exogenous cells. In this study, Osafune and his colleagues tried a different way to deliver the kidney progenitor cells. Instead of injecting cells directly into the kidney, they transplanted their iPSC-derived renal progenitors into the kidney subcapsule that is at the kidney surface.

Kidney Capsule

The mice that received the cells were suffering from acute kidney injury. Even though the transplanted cells never integrated with the host, mice that received this transplant showed better recovery, including less cell death (necrosis) and scarring (fibrosis) compared with mice that received transplants of other cell types.

Damaged kidney tissue (left) of an AKI model mouse shows high levels of fibrosis (blue). Treatment with Osr1+Six2+ cell therapy significantly ameliorates the fibrosis (right) of another AKI model mouse.
Damaged kidney tissue (left) of an AKI model mouse shows high levels of fibrosis (blue). Treatment with Osr1+Six2+ cell therapy significantly ameliorates the fibrosis (right) of another AKI model mouse.

Osafune attributed the improvement in his laboratory mice to the use of cells that expressed the Osr1 and Six2 genes. The Osr1 and Six2 proteins are known markers of renal progenitor cells, but until this particular study, researchers had not exclusively used cells that expressed both of these proteins for cell therapies.

Kidney Progenitor cells

Another conclusion from the study was that because the cells did not integrate into the kidney, their therapeutic effects were the result of secreted proteins that promoted kidney healing and protection. While most stem cell therapies aim for integration of the transplanted cells, the results of these experiments could have important clinical implications. In particular, this experiment is one of the first to show the benefits of using human iPS cell-derived renal lineage cells for cell therapy. Secondly, scarring of the kidney is a marker that indicated progression of the kidney to chronic kidney disease. Since scarring was significantly reduced in these experiments, these data suggest that the paracrine effects of the transplanted cells could act as preventative therapy for other serious ailments. Finally, Osafune believes these effects could provide valuable clues for drug discovery. “There is no medication for acute kidney injury. If we can identify the paracrine factor, maybe it will lead to a drug.”

From:  Takafumi Toyohara, et al., “Cell therapy using human induced pluripotent stem cell-derived renal progenitors ameliorates acute kidney injury in mice” Stem Cells Translational Medicine.

Wound Healing and Human Umbilical Cord Mesenchymal Stem Cells

Previous studies have shown that human bone marrow–derived mesenchymal stromal cells have potential to accelerate and augment wound healing. However, in the clinic, it is difficult to properly culture and then use bone marrow stem cells. Human umbilical cord blood–derived mesenchymal stromal cells (hUCB-MSCs) recently have been commercialized for cartilage repair as a cell-based therapy product that uses allogeneic stem cells.

Presently, current cell therapy products for wound healing utilize fibroblasts. Is it possible that hUCB-MSCs are superior to fibroblasts for wound healing? Seung-Kyu Han and his colleagues from the Department of Plastic Surgery at the Korea University College of Medicine in Seoul, South Korea used a cell culture system to compare the ability of hUCB-MSCs and fibroblasts to heal wounds.

For their study, Han and others used diabetic mice and isolated fibroblasts from normal and diabetic mice. Then they tested the ability of these cells to heal skin wounds in the very mice from which they were isolated. A third group of diabetic mice with skin wounds were treated with hUCB-MSCs. A comparison of all three groups examined the cell proliferation, collagen synthesis and growth factor (basic fibroblast growth factor, vascular endothelial growth factor and transforming growth factor-β) production and compared them among the three groups.

The results showed that hUCB-MSCs produced significantly higher amounts of vascular endothelial growth factor and basic fibroblast growth factor in comparison to both fibroblast groups. Human UCB-MSCs were better than diabetic fibroblasts but healthy fibroblasts in collagen synthesis, and there were no significant differences in cell proliferation and transforming growth factor-β production. Human UCB-MSCs produced significantly higher amounts of VEGF and bFGF when compared with both fibroblasts.

These results suggest that Human UCB-MSCs might be a better source for diabetic wound healing than either allogeneic or autologous fibroblasts. Larger animal studies will be needed, but this particular study seems like a good start.

Adding Cyclosporin to Bone Marrow Might Increase Stem Cell Numbers, Quality, and Engraftment Efficiency

In the bone marrow, we have an army of blood cell-making stem cells called hematopoietic stem cells (HSCs) that make all the blood cells that course through our blood vessels. These cells divide throughout our lifetimes, and they replacement themselves while they generate all the red and white cells found in our blood.


HSCs are also the cells that are harvested during bone marrow aspirations and biopsies. Transplantation of HSCs can save the lives of patients with blood cancers or other types of blood-or bone marrow-based diseased.

Harvesting and transplanting HSCs is, therefore, a very important clinical strategy for treating many different types of blood disorders and diseases. However, this crucial strategy is limited by the relative rarity of HSCs in isolated bone marrow. Additionally, the number and function of HSCs deteriorate both during their collection from the bone marrow (BM) and during their manipulation outside the body. Fortunately, the development of culture conditions that best mimic the environment these cells experience in bone marrow (the so-called “HSC niche environment”) may help to minimize this loss.

Scanning electron microscopy of stem cells (yellow / green) in a scaffold structure (blue) serving as a basis for the artificial bone marrow.
Scanning electron microscopy of stem cells (yellow / green) in a scaffold structure (blue) serving as a basis for the artificial bone marrow.

One of the most important variables for HSC viability is oxygen concentration, since various studies have shown that the oxygen concentrations found in ambient air seems to be damaging to HSCs, which normally are found in rather oxygen-poor reaches in bone marrow. Researchers from the laboratory of Hal Broxmeyer at the Indiana University School of Medicine have discovered that HSCs suffer from ‘‘extra-physiologic oxygen shock/stress (EPHOSS)” if they are harvested under ambient oxygen conditions. On top of that, treatment of the collected HSCs with the immunosuppressant drug cyclosporin A (CSA) can inhibit this stress, enhance the yield of collected HSCs, and increase their transplantation efficiency.

When Broxmeyer and his colleagues compared mouse BM that had been harvested under normal oxygen concentrations (21% O2) and low-oxygen concentrations (3% O2), they observed that the hypoxic (low-oxygen) treatment caused a 5-fold increase in the number of Long Term (LT) self-renewing HSCs, and a decrease in harmful reactive oxygen species (ROS) and mitochondrial activity. Broxmeyer and others also confirmed the positive effect of hypoxia on HSC collection from human cord blood. When mouse BM collected under different conditions were assayed by competitive transplantation, the “hypoxic HSCs” engrafted more efficiently in recipient mice. This increased engraftment was not due to enhanced homing or reduced cell death. Instead it seems that the stress response to non-physiological oxygen concentrations (EPHOSS) has a rapid and significant damaging effect in HSCs.

Broxmeyer decided to take this study one step further. In mitochondria (the powerhouse of the cell), increased expression of the mitochondrial permeability transition pore (MPTP) seems to be one of the key mechanism by which oxidative stress affects HSCs.

mitochondrial permeability transition pore
mitochondrial permeability transition pore

Induction of the MPTP leads to mitochondrial swelling and uncoupled energy production (which leads to the generation of reactive oxygen species, otherwise known as “free radicals). This leads to cell death apoptosis and necrosis, and intermittent MPTP activation may also decrease stem cell function in general without killing the cells. Broxmeyer and his coworkers came upon a rather ingenious idea to use the drug cyclosporin A (CSA) to antagonize MPTP induction, since CSA inhibits the associated CypD (cyclophilin) protein. When HSCs were collected under high-oxygen conditions in the presence of CSA, there was a 4-fold increase in the recovery of LT-HSCs and enhanced engraftment levels compared to HSCs harvested in high-oxygen conditions without CSA. This link was further strengthened by examining the HSCs of mice with a deletion of the CypD gene. In these mice, HSCs collected under high-oxygen conditions showed increased LT-HSC recovery and decreased LT-HSC ROS levels compared to wild-type mice.


How, harvesting and processing HSCs from bone marrow in a low-oxygen environment within a transplant clinic is generally not possible. However, given the observed advantages, the application of CSA may represent an easy and attractive alternative. The authors of this paper (which was published in the journal Cell) note that CSA is already used in the clinic as an immunosuppressant. Therefore, this technique could potentially be rapidly adapted into bone marrow harvesting techniques.

An additional thought is that studies that use other types of stem cells for transplantation might also need to consider the effects of EPHOSS and oxygen concentration while preparing their cells in other model systems.

See “Enhancing Hematopoietic Stem Cell Transplantation Efficacy by Mitigating Oxygen Shock” from Cell by Stuart P. Atkinson

Mesoblast MPCs Improve Heart Function in Patients with Congestive Heart Failure

Mesoblast Limited is a biotechology company with a singular interest in developing cell-based, regenerative therapies to treat some rather common, but severe ailments. Mesoblast has a proprietary cell system based on specialized cells known as mesenchymal lineage adult stem cells. These mesenchymal lineage adult stem cells (MLASCs) are being designed to serve as ‘off-the-shelf’ cell products for treating heart conditions, orthopedic disorders, immunologic/inflammatory disorders and cancer.

Mesoblast has recently released the results of a Phase 2 clinical trial that utilized their therapeutic product MPC-150-IM and tested it in patients with chronic congestive heart failure. The results of this study were published in the journal Circulation Research, a high-impact journal of the American Heart Association.

Patients who suffer from advanced heart failure have a poor long-term prognosis and they also have few therapeutic options. The pumping power of their hearts is weaker than normal, and the blood moves through the heart and body at a slower than normal rate. Consequently, fluid pressure in the heart increases and the chambers of the heart respond by stretching to hold more blood to pump through the body or by thickening and becoming stiff. This helps to keep the blood moving, but the heart muscle walls may eventually weaken and become unable to pump as efficiently. The kidneys respond by causing the body to retain fluid (water) and salt, and if the fluid builds up in the arms, legs, ankles, feet, lungs, or other organs, the body becomes congested, and congestive heart failure is the term used to describe the condition.

Mesoblast decided to test their proprietary Mesenchymal Precursor Cells (MPCs) to potentially induce heart muscle repair, stimulate new blood vessel growth, decrease cell death and reduce scar formation. Earlier studies established that MPCs are safe to give to heart patients. This new study examined the ability of these cells to improve heart function in patients with congestive heart failure.

In this study, 60-patients were subjected to a blinded, placebo-controlled trial. MPCs were injected directly into the heart muscle. One of the Primary Endpoints of this study was safety.

Patients included those with ischemic or non-ischemic heart failure (due to left ventricular systolic dysfunction), and in both groups, MPC injections were feasible and safe. There was a similar incidence of adverse events across all control and treatment groups. The patients who were treated with MPCs did not show any clinically significant immune response again the injected MPCs.

When it came to the main Secondary Efficacy Endpoints, patients who were treated with the highest MPC dose showed the greatest improvement in left ventricular remodeling compared to controls as evidenced by significant reductions in Left Ventricular End Systolic Volume (LVESV; p=0.015), and Left Ventricular End Diastolic Volume (LVEDV; p=0.02), 6 months after the treatment. LVESV and LVEDV increase as the heart gets weaker, but in these patients, the LVESV and LVEDV decreased. There were also parallel improvements in ejection fraction, but these improvements were not statistically significant. Patients treated with the highest dose of MPCs also showed the greatest improvement in functional exercise capacity compared to controls (p=0.062) 12 months after receiving their treatments.

Finally, in a post-hoc analysis of all patients 36 months after treatment, patients treated with MPCs showed significantly lower incidence of major adverse cardiac events when compared to the control group (0% vs 33% HF-MACE by Kaplan-Meier, p=0.026 by log-rank).

In their article, entitled ‘A Phase II Dose-Escalation Study of Allogeneic Mesenchymal Precursor Cells in Patients With Ischemic or Non-Ischemic Heart Failure’, the authors concluded that high-dose MPC treatment seems to reduce heart failure-related major adverse cardiovascular events and provide beneficial effects on adverse left ventricular remodeling.

Lead author and investigator Dr Emerson C. Perin, Director, Research in Cardiovascular Medicine and Medical Director of the Stem Cell Center at the Texas Heart Institute, said: “The findings from this trial are very encouraging and suggest that a high-dose of Mesoblast’s allogeneic cell-based therapy may decrease major clinical events associated with progressive heart failure for at least three years, including repeated hospitalizations or death.

“These effects appear to be due to the ability of these cells to positively impact on adverse cardiac remodeling associated with chronic heart failure. If these results are confirmed in the ongoing Phase 3 trial currently recruiting at our institution and elsewhere, this new therapy has the potential to change the paradigm for the management of patients with advanced heart failure and a high risk of hospitalization and death,” Dr Perin added.

A randomized, placebo-controlled Phase 3 trial using Mesoblast’s high-dose MPC 150M is being conducted by Mesoblast’s development and its commercial partner, Teva Pharmaceutical Industries Ltd. Presently, this study is actively enrolling patients across multiple clinical sites in North America.

Defending Planned Parenthood with Medical Language

The possibility that an organization like Planned Parenthood is selling fetal tissue procured from the dismembering of unborn children is deeply troubling.  However, some of the statements offered by defenders of Planned Parenthood are quite revealing.

In the New Republic, Dr. Jen Gunter, an OB/GYN makes the following statements:  “These are not ‘baby parts.’ Whether a woman has a miscarriage or an abortion, the tissue specimen is called “products of conception.”  This is pure rubbish.  Unborn babies are still babies whether you want to call them that or not.  Parts of their bodies are therefore baby parts.  I will grant that these are fetal baby parts, but they are baby parts all the same.  If they were not, then why would biotechnology companies or university research laboratories find them so valuable?  Because they are cells, tissues, and organs from unborn babies.  A very young human embryo results from conception (or the completion of fertilization), and this young embryo represents the earliest stages in the life of a human person.  “Products of conception” is a general term to describe the bodies of unborn after they die either by natural or unnatural means.    The term says nothing about how the unborn baby died, when they died, or why they died.  Likewise when an adult dies their body is called a “cadaver.”  The term says nothing about how the individual died, and neither does it reduce the humanity of the person who just died.  Therefore what we call an unborn baby’s lifeless body does not detract from the fact that this unborn baby in the fetal or embryonic stage of development is a young, unborn human person and, yes, a baby, albeit one who has yet to be born.

Dr. Gunter continues:  “The term baby is medically incorrect as it doesn’t apply until birth. Calling the tissue “baby parts” is a calculated attempt to anthropomorphize an embryo or fetus. It is a false image—a ten to twelve week fetus looks nothing like a term baby—and is medically incorrect.”  If the term “baby” is medically incorrect, then why did the documentary “Twice Born” about fetal surgery refer to this procedure as surgery on an “unborn baby.”  This is not anthropomorphizing unborn babies.  Look at the picture below of a ten-week-old baby and tell me that this unborn child does not look like a human baby.  Despite her incipient state, she is clearly a very young human baby at this stage.


There is nothing false about this image.  When we end the life of a ten-week-old baby like this one we are killing an unborn baby.  All the defining it out of existence and medicalese will not change that.

“Hearing medical professionals talk casually about products of conception may seem distasteful to some, but not to doctors. Medical procedures are gory by nature.”  She then goes on to discuss medical procedures that include surgery.  The procedures described are designed to save lives and not end them.  We find the cavalier discussion of the trafficking of baby parts distasteful because it results from the physical dismembering of the weakest and most vulnerable members of the medical community.  To place abortion alongside life-saving procedures like cutting out cancers or dealing with broken limbs is a non sequitur of the first order.

Then she claims that “ contacted several researchers who work with human tissue, and the price range mentioned in the videos—$30 to $100 per patient—is on the low-end. ‘There’s no way there’s a profit at that price,’ Sherilyn J. Sawyer, the director of Harvard University and Brigham and Women’s Hospital’s Biorepository, told the website.”  Since Dr. Sawyer does not run an abortion clinic, how would she know?  I will grant that she knows about compiling with federal law when it comes to the procurement of fetal tissue, but how would she know how much it costs the clinics?  If the companies or tissue repositories are coming into the clinics and taking the tissue straight after the procedures are performed, as mentioned in the videos, what expenses are incurred besides paperwork costs?  If the tissue is shipped there are shipping costs, but those are paid by the company.  In these videos, there was no talk of covering administrative costs, which is allowed by law.  Instead there was talk of prices for fetal tissue for the clinics for the sake of profit and that is illegal (see statute above).  How would we know if the clinics are making a profit off this unless they are investigated?  Dr Gent’s entire argument is irrelevant and a dodge.

Finally, Dr. Gent equates those who are troubled by these videos with those who deny the moon landings.  This is ridiculous and is the sign of a failed, desperate argument.  She writes, “there are those who refuse to believe that the full scope of reproductive health care is grounded in medical evidence.”  Well the medical evidence shows that abortion ends the life of the youngest members of the human community who are at their weakest and most vulnerable simply because, in the vast majority of the cases, they have the misfortune of being an inconvenience.  Equating those of us with the sense to see that with people who deny the moon landing is risible.

Hopefully Congress will do what they need to do and the Justice Department will do what they should do, but in this highly politicized administration, I would not hold my breath.

Planned Parenthood and Fetal Tissue Procurement

Unless you have been without any internet access for the past month or so, you have probably heard about the undercover videos made by David Daleiden of the Center for Medical Progress that feature the chief medical director of Planned Parenthood, Dr. Deborah Nucatola,  discussing the sale of fetal tissue that results from an abortion, and Dr. Mary Gatter, the Medical Directors’ Council President for Planted Parenthood doing essentially the same thing.

The emotional impact of these videos are immense, but I would like to try to step back from that and discuss the legal side of these videos.  Fetal tissue procurement is heavily regulated by the Federal government.  The specific laws that regulate human fetal tissue procurement are shown below:

42 U.S. Code § 289g–2 – Prohibitions regarding human fetal tissue
a) Purchase of tissue
It shall be unlawful for any person to knowingly acquire, receive, or otherwise transfer any human fetal tissue for valuable consideration if the transfer affects interstate commerce.
(b) Solicitation or acceptance of tissue as directed donation for use in transplantation
It shall be unlawful for any person to solicit or knowingly acquire, receive, or accept a donation of human fetal tissue for the purpose of transplantation of such tissue into another person if the donation affects interstate commerce, the tissue will be or is obtained pursuant to an induced abortion, and—
(1) the donation will be or is made pursuant to a promise to the donating individual that the donated tissue will be transplanted into a recipient specified by such individual;
(2) the donated tissue will be transplanted into a relative of the donating individual; or
(3) the person who solicits or knowingly acquires, receives, or accepts the donation has provided valuable consideration for the costs associated with such abortion.
(c) Solicitation or acceptance of tissue from fetuses gestated for research purposes
It shall be unlawful for any person or entity involved or engaged in interstate commerce to—
(1) solicit or knowingly acquire, receive, or accept a donation of human fetal tissue knowing that a human pregnancy was deliberately initiated to provide such tissue; or
(2) knowingly acquire, receive, or accept tissue or cells obtained from a human embryo or fetus that was gestated in the uterus of a nonhuman animal.
(d) Criminal penalties for violations
(1) In general
Any person who violates subsection (a), (b), or (c) shall be fined in accordance with title 18, subject to paragraph (2), or imprisoned for not more than 10 years, or both.
(2) Penalties applicable to persons receiving consideration
With respect to the imposition of a fine under paragraph (1), if the person involved violates subsection (a) or (b)(3), a fine shall be imposed in an amount not less than twice the amount of the valuable consideration received.
(e) Definitions
For purposes of this section:
(1) The term “human fetal tissue” has the meaning given such term in section 289g–1 (g) of this title.
(2) The term “interstate commerce” has the meaning given such term in section 321 (b) of title 21.
(3) The term “valuable consideration” does not include reasonable payments associated with the transportation, implantation, processing, preservation, quality control, or storage of human fetal tissue.

If we wade through the legalese, we can see that you cannot sell fetal tissue.  It has to be donated and it cannot come from a pregnancy whose sole purpose was to provide a source of fetal tissue.  You may not sell it for a profit.  You may also not transplant it.  All of this is meant to prevent women from having babies so they can sell their parts for money.  For this reason, abortion clinics may not use the possibility of fetal tissue donation as an inducement to persuade women to have an abortion.

In both of these videos, Planned Parenthood executives, not people who run individual centers, medical directors, which makes this official Planned Parenthood policy, actively discuss the prices of fetal organs.  That reflects an intent to sell fetal organs and that means that these videos reflect an intent to break a Federal law.  If this reflects routine Planned Parenthood policy and/or practice, then they are routinely breaking the law.

As you can see, at the very least, this deserves an investigation.  If Planned Parenthood clinics routinely charge biotechnology companies beyond their normal administrative and medical costs for fetal tissue, then they are breaking the law.  Maybe that is not the case (I highly doubt it frankly, but that’s my take), but we do not know without an investigation.  The Justice Department should become involved quickly and all federal funding of Planned Parenthood should be suspended pending full cooperation with a Federal investigation.  This should be the minimal results of these troubling videos.

Genetically Engineered Stem Cells to Treat Osteoporosis in Mice

Osteoporosis is a nasty condition characterized by weak and brittle bones often leading to devastating bone fractures and other injuries. Unfortunately, millions of people worldwide have been diagnosed with osteoporosis.


Contrary to popular belief, out bones are dynamic organs that undergo constant remodeling consisting of bone resorption and renewal. However, once bone resorption rates outpace bone renewal, bone densities decrease, which puts bones at risk of fractures. Medical researchers are would like to find new ways to not only discourage bone resorption, but generate new bone material to replace demineralized bone. Ideally, therapies would rejuvenate bone growth so that it the bone reverts back to its original density levels.

Now a promising strategy to accomplish this goal is relies on stem cell therapy. A collaborative study by Xiao-Bing Zhang and his colleagues from Loma Linda University and Jerry L. Pettis from the Memorial VA Medical Center has built on their prior work with genetically modified hematopoietic stem cells (HSCs) that identified a growth factor that caused a 45% increase in bone strength in mouse models. This work was published in the journal Proceedings of the National Academy of Sciences, USA.

Zhang and his coworkers wanted to find a gene therapy that promotes bone growth while minimizing side effects. To that end, Zhang’s group focused on a growth factor called PGDFB or “platelet-derived growth factor, subunit B.” The properties of this growth factor make it a promising candidate, since it is already FDA approved for treating bone defects in the jaw and mouth.

platelet-derived growth factor, subunit B
platelet-derived growth factor, subunit B

First, Zhang and others isolated HSCs from the bone marrow of donor mice. HSCs were chosen because they can be given intravenously, after which they will home in to one of the major sites of bone loss (the endosteal bone surface). The isolated HSCs were then genetically engineered to overexpress the growth factor PGDFB. Experimental mice were then irradiated to wipe out their own HSCs, and then these same mice were transplanted with the modified HSCs.

After four weeks, the upper leg bones of the mice (femur) were tested. Zhang and his colleagues found that PGDFB promoted new trabecular bone formation, but because the PGDFB was expressed at high levels, it negatively affected bone mineral density. Zhang and others then used weaker promoters to optimize the dosage of PGDFB expression in the HSCs. They discovered that the phosphoglycerate kinase promoter (PGK) worked well to mitigate the amount of PGDFB that is expressed in cells. When these HSCs were transplanted into irradiated mice, they observed increases in trabecular bone volume, thickness, and number as well as increases in connectivity density. Additionally, cortical bone volume increased by 20-30% while cortical porosity was reduced by 40%. Importantly, the lower dosage of PGDFB resulted in no observed decreases in bone mineral density due to osteomalacia or hyperparathyroidism.

These treated femurs and a control sample underwent three-point mechanical testing to test the integrity of the new bone. The PGK-PGDFB-treated femur displayed a 45% increase in maximum load-to-failure in the midshaft of the femur and a 46% increase in stiffness, indicating quality bone formation. Thus the new bone that is deposited it also of high quality.

The next step in this work would like to determine why this combination of a PGK promotor and PDGFB worked so well. Zhang and others have discovered that PDGFB promotes bone marrow mesenchymal stem cell formation and angiogenesis, which are two important factors in bone growth. They also found that optimizing the dosage of PDGFB is quite important for promoting osteoblast (bone-forming) cell formation.

Finally Zhang’s group investigated how osteoclastogenesis, or the creation of cells that reabsorb bone (osteoclasts) is affected by PDGFB with a PGK promotor. The treated femurs also had an increase in biomarkers for osteoclasts. This increase in both osteoblasts and osteoclasts indicates that the treated bones undergo the normal bone rebuilding and remodeling cycle.

Overall, this research provides a compelling investigational pathway for future cell therapies to treat osteoporosis. Mouse models show a fast-acting technique that result in bone formation and increasing bone strength.

Liver-Based Stem Cells Regenerate Animal Livers

Biologists from the MRC Center for Regenerative Medicine at the University of Edinburgh have managed to restore liver function in mice by using stem cell transplants to regenerate them. This is the first time such a procedure has succeeded in a living animal.

If liver stem cells from human livers behave the same way as did the mouse cells in this study, then this procedure could potentially be used in place of liver transplants in human patients. This work was published by Professor Stuart Forbes and his colleagues in the journal Nature Cell Biology.

According to Forbes: “Revealing the therapeutic potential of these liver stem cells brings us a step closer to developing stem cell based treatments for patients with liver disease. It will be some time before we can turn this into reality as we will first need to test our approach using human cells. This is much needed as liver disease is a very common cause of death and disability for patients in the UK and the rest of the world.”

Liver cells are also called “hepatocytes” and even though such cells are used for liver transplants, the technology does not yet exist to easily propagate human hepatocytes in the laboratory. In this study, Forbes and his group designed a protocol that could wipe out close to 98% of the cells in the liver of laboratory mice. They genetically engineered mice whose liver cells would delete the MDM2 gene. The MDM2 gene encodes a protein called “E3 ubiquitin ligase,” which is an enzyme that tags junk proteins so that they are properly degrades and recycled. Without a functional E3 ubiquitin ligase, the vast majority of the liver cells underwent programmed cell death. Under these conditions, a group of liver-specific stem cells called hepatic progenitor cells or HPCs were transplanted from healthy mice into the adult mice with severely damaged livers. The transplanted HPCs significantly restored the structure of the liver, regenerating hepatocytes and the cells of the “biliary epithelia,” which compose the ducts that move bile into the gall bladder. This highlights the potency of these transplanted HPCs as liver regenerators. Essentially, after several months, Forbes and his coworkers discovered that major areas of the liver had regrown and these new cells significantly improved the liver’s physiological performance.

Transplanted hepatic progenitor cells can self-renew (yellow, left image) and differentiate into hepatocytes (green) to repair the damaged liver. Image credit: Dr Wei-Yu Lu.
Transplanted hepatic progenitor cells can self-renew (yellow, left image) and differentiate into hepatocytes (green) to repair the damaged liver. Image credit: Dr Wei-Yu Lu.

This is the first time that biologists have succeeded in regenerating an organ in a living animal by using stem cells. Even human cells have significant differences from mouse cells, if these human cells can be manipulated so that they behave in a similar manner to these mouse stem cells, transplanting stem cells or, perhaps administering drugs that activate a patient’s own liver to produce stem cells and regenerate itself, could replace liver transplants.

In a press release, Dr. Rob Buckle, director of science programs for the U.K.’s Medical Research Council, said: “This research has the potential to revolutionize patient care by finding ways of co-opting the body’s own resources to repair or replace damaged or diseased tissue. Work like this, building upon a precise understanding of the underlying human biology and supported by the UK Regenerative Medicine Platform, will give doctors powerful new tools to treat a range of diseases that have no cure, like liver failure, blindness, Parkinson’s disease and arthritis.”

Umbilical Cord Stem Cells Improve Heart Function after a Heart Attack

The umbilical cord connects the baby to the placenta and contains umbilical arteries, umbilical veins, and a gooey material between the umbilical vessels called Warton’s jelly. Warton’s Jelly (WJ), besides being rich in extracellular matrix molecules also contains a mesenchymal stem cell population that is rather primitive. These WJ mesenchymal stem cells or WJMSCs have excellent potential for therapeutic strategies.

Lian Gao and her colleagues from the Navy General Hospital in Beijing, China, in collaboration with coworkers from the Shenzhen Beike Cell Engineering Research Institute in Shenzhen, China conducted a clinical trial that examined the use of these WJMSCs in human patients who had suffered a heart attack.  The results are as interesting as they are suggestive and were published in the journal BMC Medicine.

First we must consider the design of the study. Gao and others recruited 160 heart attack patients who were no younger than 18 and no older than 80-years old. All patients had to be free of liver or kidney disease, cancer or some other terminal illness. They were admitted to 11 hospitals in China between February 2011 and January 2012 and had suffered from a documented heart attack as defined by symptoms and their EKG (ST elevation). All patients has also been treated with the implantation of a stent within 12 hours of their heart attack and still retained a respectable amount of movement of the heart wall in the left ventricle. If patients were outside these parameters, they were excluded from the study.

Of the 160 patients who were recruited for the study, 44 were excluded, either because they did not fit within the exclusion criteria, did not wish to participate in the trial, or opted out for undisclosed reasons. This left 116 patients who were randomly assigned to the placebo group or the experimental group (58 in each group). Of these two groups, the placebo group had one patient discontinue the study because of a bout with stomach cancer. The experimental group had one patient die ten days into the trial, another was lost because they moved and a third patients withdrew because of leukemia. This left 57 subjects for the placebo group and 55 for the experiment group who went through all 18 months of follow-up after their respective procedures.

There were two end points for this clinical trial after patients were observed for 18 months after the procedure. The first was safety and this was measured by examining the number of adverse effects (AEs) within these 18 months. Such AEs include things like death, hospitalization for worsening heart function, severe arrhythmias, repeated coronary intervention, blood clots forming in the stents (stent thrombosis), coronary artery obstruction, and the growth of extra tissue in the heart that does not belong there, disorders of the immune system and so on. The second end pointy was efficacy of the implanted cells. To ascertain this, the function of the heart was measured using positron emission computer tomography (PET), and single-photo-emission computer tomography or SPECT. These imaging procedures allow cardiologists to take very precise snapshots of the heart and determine with a good deal of accuracy the performance of the heart.

The WJMSCs were acquired from umbilical cords that were donated from healthy mothers who had delivered healthy babies by means of Caesarian section. 21 of these umbilical cords had their blood vessels removed and then the gelatinous tissue surrounding the vessels was removed, sliced up, and cultured. The MSCs in the gelatinous tissue, which is Warton’s Jelly, migrated from the WJ to the culture dishes. After three passages in the culture dishes, he cells were harvested, concentrated, and tested for viruses, toxins, and cell viability. All cells were negative for viruses and toxins and other contaminants, and were also clearly MSCs, based on the ensemble of cell surface proteins that presented on their membranes, and showed high degrees of viability.

In infuse the cells into the hearts of the patients, six million WJMSCs were delivered into the coronary arteries using the usual over-the-wire techniques that are used to place stents, except that instead of placing stents, WJMSCs were slowly released into the coronary arteries. The cells will home to the damaged heart tissue and are able to pass through the blood vessels into the area of the infarct. Patients receiving the placebo, only received infusions of physiological saline solution, which was used to resuspend the WJMSCs.

The results are very encouraging. With respect to safety, the number of AEs was approximately the same for both groups. In the words of the study, “The groups did not differ in occurrences of MACEs (major adverse cardiac events), including death, recurrences of AMIs (acute myocardial infarctions) and re-hospitalization due to heart failure, during the course of treatment and the 18-month follow-up period.” There were no indications of cancer or the increase in tumor-specific molecules in the blood of the patients from either group. No biochemical or immune abnormalities were observed in any pf the patients either. The stomach cancer in one patient in the placebo group and leukemia in a patient from the experimental group were shown to be unrelated to the procedures. Therefore, at 18 months after the procedure, the infusion of these cells appears to be safe.

As to the efficacy of the procedure, there were significant improvements in the heart function of patients who had received the WJMSCs over those who had received placebo. First of all, the baseline heart function of patients in both groups was approximately the same on the average, except that the patients in the experimental group had slightly better heart parameter than those in the placebo group. Therefore, the efficacy of this procedure was determined by measuring the change in heart performance after the procedure. Patients who had received the placebo had about a 3% increase in the uptake of the F18-labeled sugar molecule after 4 months. The uptake of this marker indicates the presence of live cells. An increase in uptake of the modified sugar molecule shows that some new heart tissue has been produced, probably by the resident stem cell population in the heart. The experimental group, however, after 4 months showed an approximate 7% increase in PET signal intensity. This shows that a good deal more heart cells are being formed in the WJMSC-treated hearts that in the placebo-treated hearts. The SPECT imaging assays the “perfusion” of the heart tissue or the degree to which the heart tissue is being fed by blood vessels. After a heart attack, the dead area of the heart lacks blood vessels and its poor perfusion can affect nearby areas. The placebo-treated patients had a roughly 4% increase in SPECT signal, whereas the WJMSC-treated group had a 7% increase. Thus, the WJMSC-treated hearts had more blood vessels to feed the blood, oxygen and nutrients to the heart muscle and therefore, better perfusion.

Finally, the percentage of blood ejected by the heart during each contraction increase about 3% in the placebo group, but increase by about 8% in the WJMSC-treated group after 18 months. This parameter of heart function, the ejection fraction, is a very important measure of heart function and the fact that it significantly increased in the WJMSC-treated patients over the placebo-treated patients is an important finding.

This was a double-blinded, placebo-controlled study that determined the safety and efficacy of infusions of WJMSCs into the hearts of patients who had recently suffered from a heart attack. In animal experiments, these cells have been shown to increase heart function, increase blood vessel density in the hearts of animals, and increase resident heart-specific stem cell activity in the heart (see Lupu and others, Cell Physiol Biochem 2011; 28:63-76; Gao and others, Cell Transplant 2013; 22:1883-1900; Lopez Y, and others, Current Stem Cell Res Ther 2013;8:46-59). This clinical trial suggests that those benefits documented in laboratory animals might translate to human patients.

This is not a perfect study. These patients will need to be followed for several years to establish that these benefits are long-term and not short-term. Also, there is no indication that patients were given a 6-minute walking test to determine if the improvements in cardiac function translated to improvements in basic activities. However, it is an interesting study and it suggests that banking WJMSCs in addition to cord blood might be a good idea for use in trials like this one and maybe, someday for treatments of heart attack patients.

Bone Marrow Stem Cells Treat Chronic Pain

Nerve damage as a result of type 2 diabetes, surgical amputation, chemotherapy and other conditions can lead to chronic pain. Such chronic pain can resist painkiller medications and other treatments and is debilitating.

New studies from scientists at Duke University with mice have shown that injections of bone marrow-derived stem cells might be able to relieve this type of chronic, neuropathic pain. This study was recently published in the Journal of Clinical Investigation and might be the springboard for advanced cell-based therapies to treat chronic pain conditions, lower back pain and spinal cord injuries.

Ru-Rong Ji, professor of anesthesiology and neurobiology at the Duke School of Medicine and his team used bone marrow stromal cells (BMSCs) that were isolated from bone marrow aspirations. BMSCs have been shown in a variety of clinical trials and basic research experiments to produce an array of healing factors and can differentiate into many cell types of cells in the body. BMSCs are being tested in small-scale clinical studies with people who suffer from inflammatory bowel disease, heart damage and stroke. BMSCs might also be useful for treating pain, but it’s not clear how they work.

“Based on these new results, we have the know-how and we can further engineer and improve the cells to maximize their beneficial effects,” said Professor Ji. In his team’s study, stromal cells were used to treat mice with pain caused by nerve damage. The cells were delivered by means of lumbar puncture, which infused the BMSCs into the cerebrospinal fluid (CSF) that bathes the spinal cord.


Mice treated with the bone marrow stromal cells were much less sensitive to painful stimuli after their nerve injury in comparison with untreated mice.

“This analgesic effect was amazing,” Ji said. “Normally, if you give an analgesic, you see pain relief for a few hours, at most a few days. But with bone marrow stem cells, after a single injection we saw pain relief over four to five weeks.”

When the spinal cords of the treated animals were examined in detail, Ji and others observed that the injected stem cells had clustered together along the nerve cells in the spinal cord.

To understand how the stem cells alleviated pain, Ji and his coworkers measured levels of anti-inflammatory molecules that have been linked to pain suppression. One of these molecules in particular, TGF-β1, was present in higher amounts in the CSF of the stem cell-treated animals compared with the untreated animals.

Immune cells typically secrete TGF-β1, which is a small protein, and it is found at low concentrations throughout the body. According to Professor Ji, people with chronic pain have been shown to possess too little TGF-β1.

In the new study, when Ji and others chemically neutralized TGF-β1 in the stem cell-treated animals, the pain-killing benefit of the infused BMSCs was reversed. This suggests that the secretion of this protein by BMSCs was a major reason these are able to abate neuropathic pain. When Ji and his crew directly injected TGF-β1 into the CSF, it provides significant pain relief, but only for a few hours, according to Ji.

However, infused BMSCs, remain at the site of infusion for as long as three months after their administration. This is just the right length of time for the cells to persist, according to Ji, because if the stem cells permanently persisted in the CSF, they have an increased risk of becoming cancerous.

Even more significantly, infused BMSCs also migrate to the site of injury. The ability of these cells to migrate to the site of injury depends on a molecule secreted by the injured nerve cells called CXCL12 (which, incidentally, has also previously been linked to neuropathic pain). CXCL12 (also known as stromal cell-derived factor-1) acts as a homing signal, since BMSCs have on their cell surfaces, a receptor for CXCL12 called CXCR4, CXCL12 acts as a kind of stem cell attractant.

In the next set of experiments, Ji and his colleagues would like to find a way to make the stromal cells more efficient. “If we know TGF-β1 is important, we can find a way to produce more of it,” Ji said. Additionally, the cells may produce other pain-relieving molecules, and Ji’s group is working to identify those.

Healing Damaged Lungs with Stem Cells

Emphysema, bronchitis, asthma and cystic fibrosis are all diseases of the airways and they are the second leading cause of death worldwide. Over 35 million Americans alone suffer from chronic respiratory disease.

Scientists from the Weizmann Institute have now proposed a new direction for treating these diseases that might lead to a new method for alleviating some of their suffering. The study’s findings, which were published in Nature Medicine, show that it might be possible to use fetal stem cells to repair damaged lung tissue.

Particular stem cells normally found in the lungs are highly similar to those in the bone marrow. Organ-specific stem cells tend to be concentrated in special compartments rather than being distributed throughout the tissue. This insight prompted Prof. Yair Reisner of the Weizmann Institute’s Immunology Department to suggest: “That understanding suggested to us that we might be able to apply our knowledge of techniques for transplanting bone marrow stem cells to repairing lung tissue.”

Bone marrow transplants are based on two main principles: the ability of stem cells to navigate through the blood to the appropriate compartment and the prior clearing out of the compartment to make room for the transplanted stem cells. Dr. Reisner and his group thought it might possible to apply these principles to introducing new stem cells into the lungs. However, before they could do this, they needed to find a source of lung stem cells suitable for transplanting.

Reisner and his co-workers used fetal lung tissue from mice and humans (20–22 weeks of gestation for humans, and embryonic day 15–16 or E15–E16 for mice). Cells from these stages have differentiated into lung progenitor cells and are fully capable of lung regeneration. Reisner and his colleagues conducted a series of experiments in which they cleared the lung’s stem cell compartments with a new method developed on their own laboratory, and then were injected these new lung progenitor cells into mouse models of lung damage. The fetal lung stem cells found their way through the blood to the lungs and settled into the proper compartment. By six weeks, these cells were well on their way to differentiating into normal lung tissue. In these mice, their damaged lungs healed, and their breathing improved significantly.

Next, Reisner intends to determine the correct dosage of drugs that are needed to prevent rejection of the transplanted cells, which will be needed following such procedures. “But our real vision, bolstered by this success,” says Reisner, “is to create a bank of lung tissue that will be a resource for embryonic lung stem cells.” This bank could mean that there is a ready source of cells for repairing the damage in those with severe respiratory disease.

Reisner’s work shows that fetal lung progenitors can repopulate lungs and heal them. If Reisner can find a way to generate early lung progenitors from pluripotent stem cells, then such cells can be used to heal damaged lungs.

Cord Blood Stem Cells to Treat Pediatric Stroke

Cord Blood Registry (CBR) has announced the launch of an FDA-regulated clinical trial to investigate the use of autologous stem cell therapy in children who have been diagnosed as victims of prenatal or perinatal pediatric stroke. This trial will be conducted at the Florida Hospital for Children and is a Phase 1 trial. It is the first trial to examine the use of newborn autologous stem cell therapy in the treatment of pediatric stroke. Hopefully, this trial will lead to Phase 2 studies that will further assess safety and measure efficacy in the use of stem cells to improve common symptoms of this condition.

According to data compiled by the American Stroke Association, strokes occur in about one in every 3,500 new born infants, and is one of the leading causes of death in children between ages 1 and 19. Approximately 60 percent of those children who survive as stroke will have permanent neurological deficits, most commonly cerebral palsy and hemiparesis or hemiplegia, which refers to total or partial paralysis on one side of the body. Other long-term disabilities caused by a stroke occurring around the time of birth can include epileptic seizures, spasticity and bladder control issues. Stroke risk in children is greatest in the first year of life, and peaks during the perinatal period, approximately the few weeks before and immediately after birth.

“There is a critical need for the development of new treatments as the incidence and prevalence of pediatric stroke has increased over time,” said Dr. James Baumgartner, pediatric neurosurgeon and principal investigator of the trial. By supporting this and other trials and investing in the types of regenerative medicine research that hold significant potential to meet the future needs of families, CBR is helping advance newborn stem cell research and therapies.”

Recruitment is underway to enroll 10 children between the ages of 6 weeks and 6 years who experienced a stroke in utero or immediately after birth, and who have a CBR-processed cord blood unit that was collected at birth. Subjects will first receive a baseline neurologic evaluation which includes brain imaging, evaluation of epilepsy, nerve impulses, and bladder control issues, which will help assess the overall severity of the stroke’s impact prior to treatment. After this evaluation is complete, eligible patients will receive a single autologous stem cell infusion, with follow-up testing to occur after six and 12 months. The hypothesis is that the autologous stem cells will help repair the damage incurred during the stroke.

Stroke risk factors, symptoms, prevention efforts, and treatment are often different in children than those in adults. More research is needed to better understand the unique aspects of diagnosing and treating strokes in children. Families affected by pediatric stroke face numerous challenges when treating the most common symptoms, such as epileptic seizures, spasticity and bladder control issues.

First line treatment for epilepsy includes drugs known as anticonvulsants. These drugs are difficult to accurately prescribe and administer to children and seizures may still breakthrough even when anticonvulsants are administered. Common side effects such as extreme drowsiness can affect the quality of life for children and their parents. First-line treatment for spasticity is physical therapy which not only has variable efficacy but may be difficult to access and may not be covered by insurance for extended timeframes. First-line treatment for bladder related issues is catheterization, which can be cumbersome and difficult to manage.

“Our Cerebral Palsy Family Network (CPFN) has been following stem cell research and the impact it can have on children born with cerebral palsy whether it is by in-utero stroke or other brain damage. Because of our extensive reach within the CP community, our families have been asked and have participated in NIH studies including the funding of research projects. These clinical trials are critical to making a better life for children with neurological deficits,” said Janice Godwin, Executive Director of CPFN.

Once the initial 10 children are recruited, infused and evaluated at Florida Hospital for Children, the preliminary results could be available in less than three years.

Stem Cell Treatments for Diabetic Retinopathy

Research by a team at the University of Virginia School of Medicine provided a crucial piece to treating patients who suffer vision loss because of diabetic retinopathy, a condition that affects millions of people with diabetes. The UVA team showed that the best for adult stem cells to treat this condition are cells taken from donors who do not suffer diabetes rather than cells taken from patients’ own bodies. This work could provide a critical step toward injecting stem cells into patients’ eyes to stop or even reverse vision loss. These findings could also establish a crucial framework for evaluating stem cells to be used in potential future treatments for diabetic retinopathy.

Diabetic Retinopathy

“It answers a vital question: If we’re going to carry this therapy forward into clinical trials, where are we going to get the best bang for the buck?” said UVA researcher and ophthalmologist Paul Yates, M.D., Ph.D. “The answer seems to be, probably, taking cells from patients who aren’t diabetic. Because the diabetic stem cells don’t seem to work quite as well. And that’s not terribly surprising, because we already know that this cell type is damaged by diabetes.”

The researchers hope to use stem cells derived from fat, since they are harvested during liposuction procedures. These fat-based stem cells might be able to stop or greatly delay the vascular degeneration that eventually leads to blindness in patients with diabetic retinopathy. What are the best cells for the job in this case? UVA’s new research provides those important answers. “We now know what to look for when we harvest a patient’s cells, because we know what distinguishes good quality cells from poor quality,” said researcher Shayn M. Peirce, Ph.D., of the UVA Department of Biomedical Engineering. “We almost have a screen to determine quality control. We’re essentially establishing quality-control criteria by understanding what works and why.”

Diabetic retinopathy patients desperately need new and more effective treatments. First of all, there are a growing number of people with this condition and secondly the present treatments only show limited effectiveness. More than 100 million people are estimated to suffer from diabetic retinopathy and related conditions; current treatments use lasers to fight back invading blood vessels, but these treatments often destroy much of the retina. Alternatively, patients are required to receive injections of anti-blood vessel forming drugs such as Lucentis (ranibizumab) or Eylea (aflibercept) directly into their eyeball, sometimes every month, for the rest of their lives.

“There’s huge room for improvement on the standard of care, and the number of patients in this demographic is increasing by the day, dramatically, so the need is only going up,” Peirce said. “So I think there are three pieces working together — UVA’s strengths in this area, the FDA’s encouragement [of stem cell research in the eye] and the clinical realities — to drive this cell-based therapy toward the clinic.”

While much more work needs to be done, if all goes well, the UVA team hopes to begin clinical trials in humans within the next few years. “This is not science fiction at all,” Yates said. “The idea that you can take cells from somewhere else and inject them into the eye to treat disease is here today.”

Stem Cells Embedded in a Fibrin Patch Help Hearts Recover After a Heart Attack

If a patient has a heart failure, there is little you can do for them. Medications can take some of the stress off the failing heart, and in extreme cases, a heart transplant is warranted. However, organ transplants are hampered by both the limited number of organ donors and the potential for the patient’s body to reject the new heart.

A new study from the journal STEM CELLS Translational Medicine has shown that heart tissue can be regenerated if engineered patches made up of a mixture of fibrin and mesenchymal stem cells (MSCs) derived from human umbilical cord blood are applied to the heart.

Previous studies show the potential of MSCs to repair damage generated by a heart attack. In these clinical studies, the MSCs were delivered through injections into the heart muscle or intravenously. “While feasible and safe, the treatments exhibited only modest benefits,” said Antoni Bayes-Genis, M.D., Ph.D., member of the ICREC (Heart Failure and Cardiac Regeneration) Research Program, Germans Trias i Pujol Health Science Research Institute (IGTP) and professor at Universitat Auto`noma de Barcelona. Dr. Bayes-Genis is a lead investigator on this study.

“The survival rate of the implanted stem cells was generally low and about 90 percent of them either died or migrated away from the implantation site, generally to the liver,” added the study’s first author, Santiago Roura, Ph.D., also a member of the ICREC Research Program and IGTP. “These limited effects are probably due to the adverse mechanical stress and hypoxic conditions present in the myocardium after the heart attack.”

Now could a better way to deliver the MSCs to the injured site yield more efficient results? Synthetic scaffolds (or patches) in which the cells are embedded in matrices constructed of biological and/or synthetic materials and supplemented with growth or differentiation factors can generate so-called “bioimplants.” Bioimplants are a promising way to potentially apply stem cells to the heart in a way that will allow them to survive, grow and thrive. Unfortunately, none of the current materials being tested for heart patches, whether synthetic or natural has been shown to provide optimal properties for cardiac tissue repair.

Dr. Bayes-Genis and his colleagues examined how a fibrin patch filled with human umbilical cord blood-derived MSCs might serve to repair a damaged heart. Fibrin is widely used in medical applications, since it can act as a bio-compatible glue that holds cells in place and stimulating the production of new blood vessels (angiogenesis). Bayes-Genis and others hypothesized that fibrin scaffolds might offer a nurturing environment for the growth and proliferation of MSCs at the site of the heart injury. There, the cells could induce the repair of damaged heart tissue.

Bayes-Genis and coworkers mixed MSCs and fibrin to form the patches that were then applied to the hearts of mice that had undergone heart attacks. Three weeks later, they compared the recovery of these animals to a control group of mice that were treated with fibrin alone without embedded stem cells, and a third group that received no treatment at all. The results showed that the patches adhered well to the hearts and the MSCs grew and differentiated. The patch cells also participated in the formation of new, functional blood vessels that connected the patch to both the heart tissue directly beneath it and the mouse’s endogenous circulatory system, too.

“As a result, the heart function in this group of mice was better than that of the animals in either of the other control groups,” Dr. Bayes-Genis said. “Thus, this study provides promising findings for the use of umbilical cord-blood MSCs and fibrin patches in cardiac repair.”

“This is an interesting study that suggests a news strategy for using stem cells to repair injured heart tissue, without the drawbacks that cell injections have shown,” said Anthony Atala, M.D., Editor-in-Chief of STEM CELLS Translational Medicine and Director of the Wake Forest Institute for Regenerative Medicine.

Gene Therapy Helps Deaf Mice Hear

New research published in the journal Science Translational Medicine suggests that gene therapy treatments for inherited types of deafness might one day become a reality. This new report shows that fixing faulty DNA sequence in deaf mice can improve their auditory responses. In separate experiments, the drug-maker Novartis is testing a different form of gene therapy in people who have lost their hearing through damage or disease.

Safety missteps in the late 1990s and early 2000s set gene therapy research back several years. During those darker days, gene therapy scientists re-tooled and re-examined their basic assumptions about gene therapy. Even though gene therapy experiments were relatively successful in laboratory mice, humans are not mice, and a whole new set of gene therapy strategies were needed. Fortunately, as a result of this intense research, gene therapy is enjoying a modern-day renaissance. Positive clinical results were observed in clinical trials in 2013 with patients with a blood cancer called acute lymphocytic leukemia, or ALL, and last year in patients an inherited form of blindness called choroideremia.

“We are somewhat late in the auditory field but I think we are getting there now,” said Tobias Moser of the University Medical Center Gottingen, Germany, who was not involved in the new research. “It’s an exciting time for gene therapy in hearing.”

Currently, there are no approved disease-modifying treatments for disabling hearing loss; a condition that affects 360 million people, or 5 percent of the world’s population, according to the World Health Organization. Hearing aids can amplify sounds, and cochlear implants convert sounds into electrical signals for the brain to decode, but such devices cannot fully replicate natural hearing.

The vast majority of hearing loss in older people (known as presbycusis) is noise-induced or age-related, but at least half of deafness that occurs before a baby learns to speak is caused by defects in one of more than 70 individual genes. These are the infants Swiss and U.S. researchers hope to help, after showing that replacing a mutated gene improved the function of hair cells of the inner ear and partially restored hearing in deaf mice.

Scientists from the Ecole Polytechnique Federale de Lausanne and the Boston Children’s Hospital tested hearing in newborn mutant mice by seeing how high they jumped when startled by a noise (startle response). Next, this team focused on a gene called Tmc1. Mutations in Tmc1 commonly cause human genetic deafness, and accounting for 4 to 8 percent of cases of inherited human deafness. But other forms of hereditary deafness can also potentially be “fixed” using the same strategy.

For those who are interested, the Tmc1 gene encodes a protein called Transmembrane channel-like protein 1 (TMC1), which is a membrane-embedded protein that is in the plasma membrane of Hair cells in the cochlea of the inner ear. TMC1 works with another membrane protein called TMC2 to interact with a protein complex called the “Tip link” proteins.

Tip Link Protein Complex

These Tip link proteins, protocadherin 15 and cadherin 23 help TMC1 and TMC2 to transmit signaling into the hair cell when it is deformed by sound waves in the cochlea. Without TMC1, the movements of the hair cells fail to generate any signal within it, and without internal signals, the hair cell will not send any signals to the auditory nerve.

Inner Hair Cells

Jeffery Holt and his colleagues used a small virus called adeno-associated virus (AAV) and genetically modified it so that it would carry the TMC1 gene. Next, they found that by using the promoter of the chicken β-actin gene, the TMC1 gene would be highly expressed in cochlear hair cells. When the inner ears of mice were infected with the TMC1-carrying AAVs, the deaf mice showed restored sensory transduction, auditory brainstem responses, and acoustic startle reflexes. This suggest that gene therapy with Tmc1 is well suited for further development as a treatment of auditory function in deaf patients who carry Tmc1 mutations.

Jeffrey Holt of Boston Children’s said their technique still needed work to perfect it, but he is very hopeful that clinical trials in human patients will start within five to 10 years.

Work at Novartis is more advanced, with the first patient treated last October in an early-stage clinical trial that will recruit 45 people in the United States, with results due in 2017.  The Swiss company’s product, acquired in a 2010 deal with GenVec worth up to $214 million, delivers a gene called Atoh1 that acts as a master switch for turning on the growth of inner ear hair cells that are central to hearing.

Added Netrin-1 Increases Induced Pluripotent Stem Cell Production Without Affecting Stem Cell Quality

Since 2006, stem cell researchers have succeeded in generating induced pluripotent cells (iPS cells) from mature, adult cells. These cells have enormous potential applications, particularly for regenerative medicine. However, the process by which these cells are made still requires further tweaking in order to increase its efficiency and safety. Recently, two teams of researchers from Inserm, CNRS, Centre Léon Bérard and Claude Bernard Lyon 1 University have discovered a molecule that seems to favor the production of iPS cells. Their work was published in the journal Nature Communications.

Reprogramming an already specialized cell into a pluripotent stem cell was discovered in 2006 by the Japanese scientist Shinya Yamanaka. His iPS cells were capable of differentiating into any type of cell from the human body. Yamanaka and his colleagues made iPS cells by introducing into adult cells a cocktail of four genes (Oct4, Klf4, Sox2, and c-Myc). iPS cells, like embryonic stem cells, which are made from human embryos, are pluripotent, which means that they can differentiate into any mature adult cell type. iPS cells represent a promising medical advance, since they might be able to ultimately replace diseased organs with new organs that were derived from the patient’s own cells. Such technology will create tissues and organs that match the tissue types of the patient from whom the adult cells were isolated, which would eliminate all risks of transplantation rejection. The use of iPS cells would also circumvent the inherent ethical problems raised by the use of embryonic stem cells, which are derived from the destruction of human embryos.

Despite this success, cell reprogramming is besets by some problems. First of all, it is not terribly efficient; many cells undergo programmed cell death and this restricts the number of iPS cells produced. To increase the efficiencies of iPS cell production, Fabrice Lavial’s team, in collaboration with Patrick Mehlen’s team, identified new regulators of the derivation of iPS cells. They examined those genes that are regulated by the four inducing genes involved in the initiation of reprogramming. From this list of genes, they selected those genes known to have a role in programmed cell death, and whose expression varies over the course of reprogramming. This screening process yielded a gene that encodes a protein called netrin-1.

Netrin-1 is a protein naturally secreted by the body. Interestingly, netrin-1 can prevent programmed cell death, among other things. In the early days of reprogramming mouse cells, the researchers observed that their production of netrin-1 was strongly reduced, which limited the efficacy of the reprogramming process. Next, these research teams tested the effects of adding extra netrin-1 to cells during the early phases of reprogramming. This increased the quantity of iPS cells produced from mouse cells. When they repeated this experiment with human cells, the reprogramming process generated fifteen times more iPS cells than those produced by protocols without added netrin-1.

From a therapeutic point of view, it was important to determine whether this treatment affected the quality of cell reprogramming. Genomic tests, however, failed to show any deleterious effects of the use of netrin-1 on reprogrammed cells. “According to several verifications, netrin-1 treatment does not seem to have any impact on the genomic stability the iPS cells or on their ability to differentiate into other tissues,” says Fabrice Lavial, Inserm Research Fellow.

These research teams continue to test the effects of netrin-1 on the reprogramming of other types of cells. They would like to gain a better understanding of the mode of action of this molecule in stem cell physiology.

Supercharging Stem Cells for Organ Transplant Patients

A biomedical research team at the University of Adelaide has designed a novel protocol for culturing stem cells that drives the cells to grow faster and become therapeutically stronger. This research was recently published in the international journal, Stem Cells, and is expected to lead to new treatments for transplant patients.

Kisha Sivanathan , a PhD student at the University of Adelaide’s School of Medicine and the Renal Transplant Unit at the Royal Adelaide Hospital, spoke about this exciting breakthrough in stem cell research: “Adult mesenchymal stem cells, which can be obtained from many tissues in the body including bone marrow, are fascinating scientists around the world because of their therapeutic nature and ability to cultivate quickly. These stem cells have been used for the treatment of many inflammatory diseases but we are always looking for ways in which to increase stem cells’ potency,” said Ms. Sivanathan, who is the lead author on this study.

Ms. Sivanathan continued: “Our research group is the first in the world to look at the interaction between mesenchymal stem cells and IL-17, a powerful protein that naturally occurs in the body during times of severe inflammation (such as during transplant rejection). We discovered that when cultured mesenchymal stem cells are treated with IL-17 they grow twice as fast as the untreated stem cells and are more efficient at regulating the body’s immune response.”

Stem cell therapy continues to show very promising signs for transplant patients and according to Ms Sivanathan, the IL-17 treated stem cells could potentially be even more effective at preventing and treating inflammation in transplant recipients. The particular goal in this case is to treat patients who have received organ transplants; and even help control organ rejection in transplant patients.

“Current drugs (immunosuppressant drugs) used to help prevent a patient rejecting a transplant suppress the whole immune system and can cause severe side effects, like cancer. However, stem cell therapy (used in conjunction with immunosuppressant drugs) helps patients ‘accept’ transplants while repairing damaged tissue in the body, resulting in less side effects,” says Ms Sivanathan. “We are yet to undertake clinical trials on the IL-17 treated stem cells but we anticipate that because this treatment produces more potent stem cells, they will be more effective than the untreated stem cells,” she said.

Pregnancy and Delivery Unaffected in Women Patients With Crohn’s Disease Who Were Treated With Fat-Based Stem Cells

Fat is a readily accessible source of mesenchymal stem cells (MSCs). When fat is extracted by liposuction, the result is a so-called stromal vascular fraction (SVF) that contains a mishmash of mast cells (important in allergies), blood vessel-making cells, blood vessel-associated cells, fibroblasts, and MSCs. These adipose-derived stem cells (ASCs) as they are called, can be relatively easily prepared once the SVF is digested by enzymes, and centrifuges. The living adult MSCs are then rather easily identified because they adhere to plastic tissue culture plates.

Fat-based MSCs have been used in clinical studies to help heal patients with Crohn’s disease who have “fistulas.”  For a picture of a fistula, see here.  Crohn’s disease (CD) is one of a group of gastrointestinal diseases known as IBDs or inflammatory bowel diseases. CD features inflammation of any part of the GI tract, and this inflammation can affect multiple layers of the GI tract. Fistulas form when a hole is eroded through the GI tract and into another organ system. For example, in women, the rectum and erode and form an opening in the vagina. Alternatively, an opening can appear in some place other than the anus. Because of the repeated irritation and extensive inflammation of these lesions, they tend to not heal.

Beginning in 2003, Damián García-Olmo and his team at the Jiménez Diaz Foundation University Hospital in Madrid, Spain have tested the efficacy of fat-based stem cells in treating patients with CD-based fistulas.  The results have been encouraging and highly positive, since ASCs promote healing of the fistulas and decrease recovery time (see de la Portilla F, et al. (2013) Int J Colorectal Dis 28:313–323; García-Olmo D, et al. (2003) Int J Colorectal Dis 18:451–454; García-Olmo D, et al. (2005) Dis Colon Rectum 48:1416–1423; Garcia-Olmo D, et al. (2009) Dis Colon Rectum 52:79–86).

Recently, Garcia-Olmo and his colleagues examined data from several their patients who went on to become pregnant after their treatment with fat-based stem cells and even given birth. This study, which was published in the June 2015 edition of Stem Cells Translational Medicine, examined six patients from these previous clinical trials who were successfully treated with fat-based stem cells, had satisfactory resolution and healing of their lesions, and then went on to become pregnant and give birth.

Of the five women examined in this study, one was treated for rectovaginal and perinatal fistulas, two for rectovaginal fistulas only, and two others for perianal fistulas only. All women received 2 doses of 20 million and 40 million stem cells at three-four-month intervals. One patient, however, received 2 doses of 6.6 million and 20 million stem cells nine months apart.

The fertility of these women and their pregnancies were unaffected by their previous cell therapies. There were no signs of treatment-related malformations in the babies they delivered, and their bodies did not show any identifiable signs of structural abnormalities as a result of the stem cell treatments. It must be said, that all four women who delivered healthy babies (one of them even had twins) elected for Caesarian sections. The fifth woman, unfortunately, miscarried twice, both times during the first trimester.

However, even though this represents a small data set, this study does strongly suggest that injection of a patient’s own fat-based stem cells does not negatively affect a woman’s ability to conceive, the course of her pregnancy, or the health of her baby.

Stem Cell-Based Exosomes Heal Hearts After a Heart Attack

A new paper in the journal Circulation Research by a research team from the Temple University School of Medicine (TUSM) has examined the use of tiny stem cell-based vesicles to help limit the damage caused by a heart attack. Even those these experiments were performed with laboratory mice, the result are very promising.

A heart attack tends to badly damage it, and since the heart has little innate ability to repair itself, it has to compensate by growing large and flabby, which can lead to congestive heart failure, Congestive heart failure is currently responsible for one in nine deaths in the United States.

The research team of Raj Kishore at the Temple University School of Medicine turned to exosomes to heal the heart. Exosomes are tiny sacks secreted by cells that act as messengers that pass messengers between cells in various parts of the body. While these extracellular vesicles are secreted by nearly all types of cell, exosomes from stem cells might be a useful tool in mitigating damage caused by heart attacks.


“If your goal is to protect the heart, this is a pretty important finding,” Dr. Kishore said. “You can robustly increase the heart’s ability to repair itself without using the stem cells themselves. Our work shows a unique way to regenerate the heart using secreted vesicles from embryonic stem cells.”  Kishore’s group is also beginning to determine those members of this “work crew” within the vesicles may be responsible for the damage repair.

Previous studies have shown that injecting damaged hearts with stem cells increases heart function after a heart attack. However, the injected cells tend to not survive very long when placed in the damaged heart, and most of their benefits are due to molecules that the administered stem cells secrete. Pluripotent stem cells (embryonic stem cells, for example) run the risk of creating a tumor made up of a mass of cells of different tissue types, known as a teratoma. Therefore, Khan’s tram approached the problem from a slightly different angle by injecting only the exosomes made by stem cells. It was known that this would avoid the teratoma problem, and could have positive effects on damaged heart tissue.

Exosome poster

The study examined mice that had suffered heart attacks. These animals were split into two groups; one group received exosomes from mouse embryonic stem cells, and the other group were injected with fibroblast exosomes.

The results were extremely promising. The mice that had received stem cell-derived exosomes exhibited improved heart function, less scar tissue, lower levels of programmed cell death and better capillary development around the damaged area. There was also a higher presence of cardiac progenitor cells – the heart’s own stem cells – in the stem cell exosome-injected mice. Overall, the heartbeat of the mice was stronger than those in the control group, with less unhealthy enlargement of the organ.

Khan and others examined an abundant gene-regulating molecule (microRNA) from the stem cell-derived exosomes, known as miR-294. They introduced this microRNA into cultured cardiac stem cells. This microRNA recapitulated many of the positive effects of the stem cell exosomes that had been observed in the animal study.

Khan and his coworker plan to continue their research by studying the effects of individual microRNAs on damaged heart tissue.

“Our work shows that the best way to regenerate the heart is to augment the self-repair capabilities and increase the heart’s own capacity to heal,” says researcher Dr Mohsin Khan. “This way, we’re avoiding risks associated with teratoma formation and other potential complications of using full stem cells. It’s an exciting development in the field of heart disease.”

Cystic Fibrosis Gene Therapy Causes Modest Improvements

Patients with Cystic Fibrosis (CF) have a mutation in a gene that encodes a chloride pump. Without a functional chloride pump, the production of mucus by the ductal systems of the lungs and other organs produce a very thick, difficult to move mucus that tends to clog the lungs and cause suffocation. In order to live, CF patients have to take a battery of pills every day just to keep the symptoms at bay. Gene therapy could be a simpler and more effective treatment. Several clinical trials have examined the use of various gene therapy vectors to treat CF patients, but these trials have not been overly successful.

It seems that gene therapy engineers some cells with the normal copy of the CF gene, but these cells are soon sloughed off and do little good. Therefore, a new paradigm is to repeatedly administer the gene vector. This new strategy has stabilized and slightly improved lung function in a clinical trial that tested 136 cystic fibrosis patients. Patients who received the gene therapy showed no decline of lung function, but instead had a 3% improvement on average, after taking the gene therapy once a month for a year. Patients who received the placebo showed a decline of 3-4% on average over the same period. These results were published in Lancet Respiratory Medicine.

This is the first evidence worldwide which shows that if you give gene therapy to CF patients it has a protective effect.

Prof Eric Alton, of Imperial College London, who led the trial, warned: “The effect is modest and it is variable. It is not ready to go straight into the clinic yet.”

Prof Alton and his colleagues at the UK Cystic Fibrosis Gene Therapy consortium includes scientists at Edinburgh and Oxford Universities as well as Imperial College. They hope to have a further trial next year.

Cystic fibrosis leads to a buildup of thick, sticky mucus that causes debilitating infections in the nose, throat and lungs. Patients’ average life expectancy is 41.

Trial participant Kieran Kelly usually takes about 40 pills, injections and inhaled medicines throughout the day. Mr. Kelly told BBC News: “I did feel a lot healthier. It might have been psychological, but I did feel better in myself. You have to live every day that you have,” he added. “You have to be as positive as you can, just live your life and enjoy it.”

Mr. Kelly’s fiancé, Nadia Lloyd, said: “You have to be quite hopeful. When we first met [nine years ago], the average life expectancy was 28. So every time you see medical developments, it is always so encouraging”.
Unfortunately, the two of them know the new gene therapy probably will not be ready in time to help Mr. Kelly. “The chances are that it will have an effect on anyone taking part in the trials are quite slim,” he said. It would be great if it does.” However Miss Lloyd said that Mr. Kelly has already benefited from drugs developed as a result of other people taking part in previous trials. She added: “What Kieran is doing could help so many people in the future. I am very proud of him.”

Prof Stuart Elborn, of Queen’s University in Belfast, said the results were “encouraging” but the therapy had been no more effective than some of the drugs currently available. He called for more small-scale tests to see if a larger dose would be more effective. “If I was on the board of a pharmaceutical company, I would require further studies to determine the best dose and whether the current treatment could be combined with other drugs to increase the effect,” he said. “It is too soon to proceed with larger phase-three trials costing many millions.”

Cystic Fibrosis Trust chief executive Ed Owen said: “The advantage of gene therapy is that it attacks the basic defect of cystic fibrosis and that has the potential to reduce the daily routine of drugs that those with cystic fibrosis endure each day and (offers the possibility) of long-term improvement to transform their lives”.