Reversing Age-Related Tendon Damage with Reprogrammed Tendon Stem Cells

Adults over 60 are much more likely to experience tendon injuries. Since tendons connect muscles to bones, tendon injuries can lead to substantial restrictions in movement and movement-associated pain.

Injured tendons tend to be left on their own to heal and, as I can attest to from personal experience, injured tendons can take a very long time to heal.

I new study, however, shows that tendon damage can be reversed with stem cell therapies.

Hui Sun from Albert Einstein College of Medicine found that reprogramming the CITED2 in aged tendon stem cells can not only reverse age-related dysfunction of these cells, but when implanted into injured, aged tendons, these engineered tendon stem cells healed and rejuvenated the tendons.

The CITED2 gene encodes a protein that inhibits transactivation of HIF1A-induced genes. It does so by competing with binding of hypoxia-inducible factor1α to its co-factor p300-CH1.

With therapies like this, older adults, even though they may always have to contend with gray hair and wrinkles, might not be concerned about decreased mobility in their advanced years after suffering an injury.

“We are developing a novel patient- and surgeon-friendly intervention for tendon tissue repair, especially in aged individuals,” Sun said. “We’re also working on strategies to rejuvenate aged tendon and other muscuoskeletal tissues based on this discovery.”

Proteins that Control Energy Metabolism Necessary to Form Stem Cells

University of Washington scientists have discovered that the way cells degrade sugars plays a rather central role in reprogramming adult cells into pluripotent stem cells.

Julie Mathieu, a postdoctoral research fellow at the University of Washington, Wenyu Zhou, a postdoctoral scholar at Stanford University, and Hannele Ruhola-Baker, UW professor of Biochemistry, teamed up to address this problem. Their findings might have implications for the way pluripotent stem cells are made from adult cells for regenerative purposes in the future.

Reprogramming adult cells to induced pluripotent stem cells requires genetically engineering the cells with four different genes (now known as the Yamanaka factors after Shinya Yamanaka who discovered them). These four genes – Oct4, Klf4, Sox2 and c-Myc – causes the cells to de-differentiate into embryonic stem cell-like cells.

However, during reprogramming, cells change the way they make their energy. The reprogramming cells shut down the oxygen-utilizing part of metabolism and switch to a fermentative kind of metabolism that does not require the presence of oxygen.

This metabolism shift seems to mimic, in part, the metabolism of embryonic cells, which have to survive and grow in low-oxygen environments. Cancer cells also perform a similar shift in their metabolism.

Ruhola-Baker and her gang examined the function of two proteins that are known to control the use of oxygen: HIF or hypoxia-induced factor-1α and -2α. These two proteins regulate several genes involved in energy metabolism. When Ruhola-Baker and her colleagues made adult cells that lacked a functional copy of either HIF-1α or HIF-2α, these cells were unable to be reprogrammed into induced pluripotent stem cells.

When Ruhola-Baker and her team used these proteins to examine gain-of-function experiments, the results were very different. Stabilization of HIF-1α throughout the reprogramming process increased the formation of induced pluripotent stem cells from adult cells. However, stabilization of HIF-2α during the later stages of reprogramming inhibited the reprogramming process. The HIF-2α-mediated inhibition of reprogramming occurs in the presence or absence of extra HIF-1α. Thus HIF-1α increases reprogramming at all stages, but HIF-2α increases the efficiency of the early stages of reprogramming but inhibits reprogramming at the later stages.

HIF function during reprogramming

“HIF-2α is like Darth Vader, originally a Jedi who falls to the dark side,” said Ruhola-Baker. “HIF-1α, the good guy, is beneficial for reprogramming throughout the process. HIF-2α, if not eliminated, turns bad in the middle and represses pluripotency.”

How does HIF-2α repress reprogramming to pluripotency? By increasing the production of a protein called TRAIL, which stands for Tumor necrosis factor-related apoptosis-inducing ligand. TRAIL has been known to cancer researchers for some time, since it causes some cancer cells to self-destruct.  TRAIL has to be inhibited in order for reprogramming to occur.  When HIF-2α activates TRAIL, it inhibits reprogramming.

Zhoi said that their data suggests that TRAIL and other members of this protein family might be alternate between playing good cop/bad cop during stem cell development.

Practically speaking, it might be possible to use HIF-1α to increase the number of stem cells derived from adult cells in a particular experiment. This might decrease the degree to which the cells are genetically manipulated in order to form induced pluripotent stem cells.

Alternatively, since activated HIF-1α is a marker for aggressive cancers, these data might also have implications for treating cancer. Blocking HIF-1α function or stimulating HIF-2α might interfere with particular cancers. The treatment possibilities are very intriguing.

Scientist Make Cloned Stem Cells from Adult Cells

For the first time, stem cell scientists have derived stem cells from cloned human embryos that were made from adult cells.  This brings them closer to developing patient-specific lines of cells that can be used to treat a whole host of human maladies, but at a cost.  This research was described in the April 17th online edition of the journal Cell Stem Cell.

In May of last year, Shoukhrat Miltalipov from the Oregon Health and Science University, reported the derivation of human embryonic stem cells from cloned human embryos.  However, these cloned were made using cells that came from infants.  Miltalipov worked out a new protocol for cloning human embryos by using nonhuman primate embryos, in particular those from a Rhesus monkey.

In this study, the donor cells came from two men, a 35-year-old and a 75-year-old.  By using the protocol developed by Miltalipov and his group, Robert Lanza, Young Gie Chung, and Dong Ryul Lee and their colleagues made personalized embryonic stem cells from these two men.

Stem cell biologist Paul Knoepfler, an associate professor at the University of California at Davis who runs the widely read Stem Cell Blog, called the new research “exciting, important, and technically convincing.”  He continued: “In theory you could use those stem cells to produce almost any kind of cell and give it back to a person as a therapy.”

In their paper, Young Gie Chung from the Research Institute for Stem Cell Research for CHA Health Systems in Los Angeles, Robert Lanza from Advanced Cell Technology in Marlborough, Mass., and their co-authors pointed out the potential promise of this technology for new regenerative therapies.  However, their work is also an important discovery for human cloning, since it shows that age-associated changes are not necessarily an impediment to SCNT-based nuclear reprogramming of human cells.

Even though it was the intent of Chung and others to gestate these cloned embryos to form cloned children, this work could be the first step toward creating a baby with the same genetic makeup as a donor.  Thus, this technology presents a so-called “dual-use dilemma.”

Marcy Darnovsky, executive director of the Berkeley, Calif.-based Center for Genetics and Society, explained that many technologies developed for good can be used in ways that the inventor may not have intended and may not like.

“This and every technical advance in cloning human tissue raises the possibility that somebody will use it to clone a human being, and that is a prospect everyone is against,” Darnovsky said.

This paper represents a collaboration between members of academic laboratories and industry.  Funding for this work came from a private medical foundation and South Korea’s Ministry of Science.

Technically, the somatic-cell nuclear transfer protocols used in paper are still somewhat inefficient.  Chung’s team had to attempt 39 times to produce only two blastocyst-stage embryos.  Their first attempts were complete failures, but when they modified the Miltalipov protocol and activated the cloned embryos 2 hours after fusion rather than 30 minutes after fusion, the embryos grew successfully.

“We have reaffirmed that it is possible to generate patient-specific stem cells using [this] technology,” Chung said.

Shoukhrat Mitalipov, director of the Center for Embryonic Cell and Gene Therapy at Oregon Health & Science University, who developed the method that Chung’s group built upon, said that this work involves eggs that have not been fertilized.

“There will always be opposition to embryonic research, but the potential benefits are huge,” Mitalipov said.

Yes, there will be opposition to destructive research on embryos because they are the youngest among us.  No they do not have the right to vote, drive a car, or buy a hunting license, but they have the right to not be harmed.  To deny them that right because they cannot presently exercise particular capacities assumes that the embryo undergoes essential changes as it develops.  But human embryos develop into the kinds of entities they become because of their intrinsic human nature that drives them to do so.  Yes development is a progressive program that causes the embryo to acquire new structures and capabilities that it previously did not have, but what kind of entity can develop into a human adult that is not itself human?  It takes a human embryo to make a human fetus, which makes a human new-born baby, which makes a human toddler, and do on.  This continuum or development and change occurs throughout or lives and this continuum begins at the end of fertilization.

Clones embryos begin this continuum at the completion of somatic cell nuclear transfer (SCNT).  SCNT works as a stand-in for fertilization, but the result is still the same – a human embryo.  It also should have the right not to be harmed, but instead she is being produced solely for the purpose of being dismembered.  Is this the way we should treat the smallest and most defenseless among us? surely not.  All this talk about, “well we did not form a fully human being” is a crock.  Yes you did.  You formed a fully formed human embryo.  We were all human embryos at one time and these embryos developed into you and me.  We were inarticulate and incapable at the time, but we gained those capacities over time.  Again, how can something that gives rise to a human child not be human?  The embryo is a human being, but it is a very young human being.  Youth should not disqualify it from being able to live.

Seventeen years ago, when Ian Wilmut from the Roslin Institute in Edinburgh, Scotland announced news about the birth of the first sheep cloned from somatic cells named Dolly, several legislators called for a ban on human cloning.  Several countries took measures to limit or outlaw such work, but in the United States.  The cloning issue was obfuscated by dividing it into “reproductive cloning” for the purposes of making cloned children, and “therapeutic cloning” for the development of new therapies.  Unfortunately, this dichotomy is slightly disingenuous since the techniques for both of these procedures are exactly the same except that reproductive cloning uses a surrogate mother to gestate the cloned embryo and bring her to term.  Both of these procedures produce human embryos, but one uses them to make a baby and the other destroys them before they can do so.

President George W. Bush tried to split the difference by restricting federal funding for stem cell research that harms to a human embryo.  This led to talk of Bush’s “embryonic stem cell ban,” which was inaccurate and was used unfairly used to paint Bush as an idiot.  However, some 15 states have laws addressing human cloning, and about half of them ban both reproductive and therapeutic cloning.

Embryonic stem cell research has typically used embryos that are left over from the fertility industry.  However, some religious groups such as the U.S. Conference of Catholic Bishops and others as well  objected to this, since it destroys a very young human being.

However, about seven years ago, Shinya Yamanaka and his colleagues discovered a way to make induced pluripotent stem cells from mature adult cells.  Genetic engineering techniques could convert ordinary cells into pluripotent stem cells without the need for human eggs.  While this technique did not present the same ethical issues, some induced pluripotent stem cells lines contain significant genetic abnormalities and there is still debate over how safe these cells are for clinical use.

The research conducted by Mitalipov and Chung provides a second way of producing pluripotent cells through laboratory techniques that is, in my view, far less ethical and will almost certainly also have unintended consequences as well.

An Improved Way to Make Motor Neurons in the Laboratory from Stem Cells

A research team from the University of Illinois at Urbana-Champaign has reported that they can produce human motor neurons from stem cells much more quickly and efficiently than previous methods allowed. This finding was published in the journal Nature Communications and it will almost certainly provide new ways to model human motor neuron development, diseases of the nervous system, and ways to treat spinal cord injuries.

The new protocol described in the Nature Communications paper includes adding critical signaling molecules to precursor cells a few days earlier than specified by previous methods. This innovation increases the proportion of healthy motor neurons derived from stem cells from 30 to 70 percent. It also cuts in half the time required to make motor neurons.

“We would argue that whatever happens in the human body is going to be quite efficient, quite rapid,” said University of Illinois cell and developmental biology professor Fei Wang, who led the study with visiting scholar Qiuhao Qu and materials science and engineering professor Jianjun Cheng. “Previous approaches took 40 to 50 days, and then the efficiency was very low – 20 to 30 percent. So it’s unlikely that those methods recreate human motor neuron development.”

The new method designed by Qu generated a larger population of mature, functional motor neurons in 20 days. According to Wang, this new approach will allow scientists to induce mature human motor neuron development in cell culture, and to identify the factors that drive this process

Because stem cells can differentiate into a wide variety of cell types, they are unique compared to mature, adult cells. Making neurons from either embryonic stem cells or induced pluripotent stem cells requires the addition of signaling molecules to the cells at critical moments in culture.

Previously, Wang and his colleagues discovered a molecule called compound C that converts stem cells into “neural progenitor cells,” or NPCs. NPCs represent an early stage in neuronal development, and further manipulation of NPCs can drive them to become neurons, but differentiating NPCs into motor neurons presents another set of problems.

Other published studies have established that the addition of two important signaling molecules, six days after exposure to compound C, to NPCs in culture can generate motor neurons, but at rather poor efficiencies. In this newly published study, Qu showed that adding the signaling molecules at Day 3 worked better: The NPCs differentiated into motor neurons quickly and efficiently. Thus, Day 3 represents a previously unrecognized NPC cell stage.

This new approach has immediate applications in the laboratory. Amyotrophic lateral sclerosis or ALS is a neurological disease that causes motor neurons to die off. By using Wang and Qu’s cell culture system to make neurons from the skin cells of ALS, and watching them develop into motor neurons, scientists and physicians will divine other new insights into disease processes. Therefore, any method that improves the speed and efficiency of generating the motor neurons will be a boon to neuroscientists. These cells can also be used to screen for drugs to treat motor neuron diseases, and might even be used to therapeutically restore lost function in patients someday.

“To have a rapid, efficient way to generate motor neurons will undoubtedly be crucial to studying – and potentially also treating – spinal cord injuries and diseases like ALS,” Wang said.

A Protein that Signals Neurons to Regenerate

Presently damaged nerve fibers (or axons) from spinal nerves do not regenerate and there are no good ways to repair them. However, a new set of experiments suggest that the repair of these nerves might be possible after spinal cord injury or brain trauma.

Researchers from Imperial College London and the Hertie Institute, University of Tubingen, Germany, have identified a possible mechanism for re-growing damaged central nervous system nerve fibers. Such damage causes loss of sensation and permanent paralysis. However, regenerating nerve fibers is one of the best hopes for those suffering from CNS damage to recover.

This work was published in the journal Nature Communications, and this work trades on the function of a protein called P300/CBP-associated factor (PCAF). PCAF seems to be essential for the cellular pathway that damaged neurons use to properly regenerate. When PCAF was injected into mice with damage to their central nervous systems, the injected mice showed significant increases in the number of nerve fibers that regenerated. This indicates that it might be possible to chemically control the regeneration of nerves in the CNS.

“The results suggest that we may be able to target specific chemical changes to enhance the growth of nerves after injury to the central nervous system,” said lead study author Professor Simone Di Giovanni, from Imperial College London’s Department of Medicine. “The ultimate goal could be to develop a pharmaceutical method to trigger the nerves to grow and repair and to see some level of recovery in patients. We are excited about the potential of this work but the findings are preliminary.

“The next step is to see whether we can bring about some form of recovery of movement and function in mice after we have stimulated nerve growth through the mechanism we have identified. If this is successful, then there could be a move towards developing a drug and running clinical trials with people. We hope that our new work could one day help people to recover feeling and movement, but there are many hurdles to overcome first,” he added.

Of particular interest to Dr. Di Giovanni and his colleagues was how axons in the peripheral nervous system (PNS) make a concerted effort to grow back when they are damaged, whereas CNS axons mount little or no effort. Damage to the peripheral nervous system is followed by regeneration of about 30% of the damaged nerves, accompanied by recovery of some movement and function. Could neurons in the central nervous system be coaxed into a similar behavior?

Co-author Dr. Radhika Puttagunta from the University of Tubingen said: “With this work we add another level of understanding into the specific mechanisms of how the body is able to regenerate in the PNS and have used this knowledge to drive regeneration where it is lacking in the CNS. We believe this will help further our understanding of mechanisms that could enhance regeneration and physical recovery after CNS injury.”

To investigate damage and regeneration in central and peripheral nervous systems, Di Giovanni and his group examined mouse models and cells in culture. They compared the responses to PNS damage and CNS damage in a type of neuron called a dorsal root ganglion, which connects to both the CNS and the PNS.

Interestingly, they discovered that epigenetic mechanisms were at the core of the regeneration capacity of these cells. Epigenetic mechanisms are processes that, without altering our DNA, manage to activate or deactivate genes in response to the environment, and are linked to changes in the way DNA is packaged within the cell. Epigenetic considerations control genes that influence the onset of diseases such as cancer and diabetes. However this is the first demonstration of a specific epigenetic mechanism responsible for nerve regeneration.

When nerves are damaged in the PNS, the damaged nerves send ‘retrograde’ signals back to the cell body to switch on an epigenetic program to initiate nerve growth. Very little was previously known about the mechanism which allows this ‘switching on’ to occur. When DiGiovanni’s group identified the signal transduction pathway that led to the ‘switching on’ of the program to initiate nerve regrowth, they discovered that PCAF was central to this process. Furthermore when they injected PCAF into mice with damage to their central nervous system, there was a significant increase in the number of nerve fibers that grew back.

Thus, PCAF is necessary for conditioning-dependent axonal regeneration and also promotes regeneration after spinal cord injury. Thus, PCAF is a part of a specific epigenetic mechanism that regulates axonal regeneration of CNS axons, which also makes it and the protein with which it associates a novel target for clinical application.

Fat-Based Stem Cells in the PRECISE Trial Stabilizes Exercise Performance in Chronic Heart Disease Patients

Cytori Therapeutics has announced the publication of safety and efficacy data from a 36-month European clinical trial of Cytori Cell Therapy in patients with chronic ischemic heart failure. Final data from the Company’s PRECISE trial, a 27-patient, prospective, randomized, double-blind, placebo-controlled, feasibility trial (Phase I/IIA), demonstrated statistically significant differences in cardiac functional capacity between treated and placebo groups.

Their research will appear in the upcoming issue of the American Heart Journal. Cytori Cell Therapy is a mixed population of adipose derived regenerative cells (ADRCs™) extracted from a patient’s own adipose tissue using Cytori’s proprietary Celution® System.

“The PRECISE trial is the first-in-man trial involving the myocardial injection of ADRCs for heart disease,” said Dr. Emerson Perin , Co-Principal Investigator of the trial. “By demonstrating a strong safety profile and suggesting that the use of ADRCs may preserve functional capacity, the data indicates that this therapy may have meaningful impacts on the lives of these very sick patients.”

This particular publication was co-authored by trial investigators Drs. Emerson C. Perin at Texas Heart Institute, Francisco Fernández-Avilés at Hospital Universitario Gregorio Marañón and others. This clinical trial shows that the procedure was safe, feasible and showed indications of a favorable benefit to the patients who received it. The study demonstrated that fat harvest through liposuction could be performed safely in cardiac patients. Exercise capacity as reflected by maximum oxygen consumption (MVO2) during treadmill testing, a reflection of cardiac functional capacity, was sustained in the ADRC treated group but declined in the placebo group at 6 and 18 months. Statistically significant differences were observed between the two groups.

“These results supported the design of the ongoing U.S. Phase II ATHENA trial that is evaluating a similar patient population,” said Steven Kesten , M.D., Chief Medical Officer for Cytori. “We are encouraged by the sustained effects in functional endpoints, particularly MVO2, which is a relevant clinical endpoint in heart disease, and is an aid in directing treatment options, such as assist devices or heart transplant. We look forward to reporting the initial six-month results from the ATHENA trial.”

Additionally, other data trends in this study suggest that ADRC therapy may have a modest beneficial effect in stabilization of the heart scar tissue. To understand the meaning of this benefit, remember that ischemic heart disease might also be known as coronary artery disease (CAD), atherosclerotic heart disease, or coronary heart disease. Ischemic Heart Disease is the most common type of heart disease and cause of heart attacks. This disease is typically caused by plaque build up along the inner walls of the arteries of the heart, which leads to narrowing of the arteries and reduction of blood flow to the heart. After a heart attack, the region of the heart that was deprived of oxygen for a period time dies and the dead heart muscle tissue is replaced by scar tissue that contracts over time, but does not contract or conduct heartbeat impulses. In this study, the scar mass of the left ventricle remained consistent in ADRC-treated patients at six months compared to an increase in control patients. This suggests that ADRCs may prevent scar tissue from increasing. Other endpoints such as ventricular volumes and ejection fraction showed inconsistent findings.

In the PRECISE trial, all patients were treated with standard-of-care and subsequently underwent a liposuction procedure. Each patient’s adipose tissue was processed using Cytori’s proprietary Celution® System to prepare the cell therapy. Cells (n=21) or placebo (n=6) were injected into areas of the heart muscle that were severely damaged but still viable and reversible using the NOGA XP System.

Cytori is currently enrolling patients in the U.S. ATHENA and ATHENA II trials, both 45 patient prospective, randomized, double-blind, placebo-controlled trials investigating a lower and a higher dose, respectively, of Cytori Cell Therapy in a similar patient population as PRECISE.

The PRECISE study is a small study, but the fact that it was double-blinded and placebo controlled makes it an important study. The experimental group showed a clear stabilization of maximum oxygen consumption as opposed to the control group, whose exercise tolerance decreased during the course of the trial. This is potentially significant.  The ADRCs could be preventing the heart from enlarging as a result of working harder.

Questions, however, remain.  For example, is this a short-term effect or does it maintain its effect over the long-term period? To answer that, patient follow-up is necessary. Second, the other physiological parameters showed confusing outcomes (ejection fraction, end-diastolic volume, and so on).  If the ADRCs are truly helping the heart function better, then why don’t the physiological parameters used to measure heart function show some semblance of improvement?  The stabilization of the maximum oxygen consumption stabilization might not mean much in retrospect if it is short-term.

A larger trial like the ATHENA study will be more powerful. Hopefully these PRECISE patients will be followed and examined several years after the treatment to determine the duration of the ADR-provided benefits.

Repairing Muscles in Muscular Dystrophy Depends on the Degree of Muscle Deterioration

Pier Lorenzo Puri, M.D., an associate professor at Sanford-Burnham Medical Research Institute (Sanford-Burnham), has led a research team that work in collaboration with Fondazione Santa Lucia in Rome, Italy, to characterize the mechanism by which a class of drugs called “HDACis” drive muscle-cell regeneration in the early stages of dystrophic muscles, but fail to work in late stages. These findings are integral for designing HDACis drugs for Duchenne muscular dystrophy (DMD), which presently, is an incurable muscle-wasting disease.

Puri’s research was published April 15th, 2014 edition of the journal Genes and Development. In their paper, Puri and his colleagues used mouse models of DMD to show how special cells known as “fibro-adipogenic progenitor cells” or FAPs, direct muscle regeneration. FAPs reside in the spaces between muscle fibers and detect those cues that indicate that muscles have been damaged. In response to muscle damage, FAPs direct muscle stem cells, known as satellite cells, to rebuild muscle.

 HDAC inhibitors (HDACi) promote muscle regeneration in a mouse model of Duchenne Muscular Dystrophy at early stages of disease by targeting fibro-adipogenic progenitors (FAPs). Staining of FAPs from muscles of HDACi-treated young mdx mice reveals presence of differentiated muscle cells (green) at the expense of fat cells (red). Nuclei are stained in blue. Image: Lorenzo Puri, M.D.

HDAC inhibitors (HDACi) promote muscle regeneration in a mouse model of Duchenne Muscular Dystrophy at early stages of disease by targeting fibro-adipogenic progenitors (FAPs). Staining of FAPs from muscles of HDACi-treated young mdx mice reveals presence of differentiated muscle cells (green) at the expense of fat cells (red). Nuclei are stained in blue. Image: Lorenzo Puri, M.D.

“HDACis create an environment conducive for FAPs to direct muscle regeneration—but only during the early stages of DMD progression in mice,” said Puri. “At some point, DMD progresses to a pathological point of no return and become permanently resistant to muscle-regeneration cures and to HDACis.”

Indeed, Puri’s research showed exactly that; namely that FAPs embedded in muscle that was in the earlier stages of muscular dystrophy responded robustly to HDACis and upregulated a wide range of muscle-specific genes. In contrast, FAPs from late-stage dystrophic muscles were resistant to HDACi-induced muscle-specific gene expression and failed to activate satellite cells.

HDACis stands for histone deacetylase inhibitors. These are epigenetic drugs that regulate the accessibility of those genes that code for muscle proteins. HDACis ensure that the DNA within cells is open and easily accessible to the gene expression machinery. In the presence of FAPs, in particular, rev up their support for muscle regeneration. Under conditions of normal wear and tear, FAPs direct stem cells within the muscle to regenerate and repair damaged muscle. However in patients with DMD, the persistent breakdown of muscle cells creates a chaotic environment that overwhelms the ability of the FAP’s to direct muscle regeneration.

Puri collaborated with Italian colleagues at Fondazione Santa Lucia, Italfarmaco, and Parent Project Muscular Dystrophy, an advocacy association. The goal of this research is to develop HDACis for the treatment of DMD. To that end, Puri and others have launched a clinical trial with DMD boys.

“Our study is important because it provides the rationale for the clinical development of HDACis to treat DMD,” said Puri. “And, now that we understand the mechanics and sensitivities of the muscle-regeneration system, we have the rationale and can use new tools to select patients most likely to benefit from HDACIs based on their FAP profile, predict outcomes, and see how long patients should remain on the therapy.”

“Duchenne muscular dystrophy patients and their families rely on important research such as that performed by Dr. Puri,” said Debra Miller, Founder of Cure Duchenne, a patient advocacy group. “Our efforts at Cure Duchenne are to support leading scientists in the world to bring life-saving drugs to help this generation of Duchenne boys, and our vision is to cure Duchenne muscular dystrophy. Every added piece of knowledge about the disease brings us closer to realizing our goals.”

The Puri paper also shows why trying to regenerate muscle cells in severely affected individuals is not feasible, since the dystrophic muscles have deteriorated to the point of no return. This will definitely influence the construction of treatment strategies for patients with muscular dystrophy.