Drug Converts White Fat into Brown Fat and Induces Weight Loss

Exciting new research has determined that a variant of a drug used to treat pulmonary arterial hypertension induces weight-loss in obese mice. Among mice fed a high-fat diet, those who did not get the medication became obese while medicated mice did not.

The experimental drug used stimulates soluble guanylyl cyclase (sGC), and this drug is a member of the same class of novel drugs as the drug riociguat. The Food and Drug Administration approved riociguat in 2013 to treat high blood pressure in the lungs. Riocoguat is produced by Bayer HealthCare Pharmaceuticals, is marketed under the trade name Adempas.

In mice, the sCG stimulator stimulated a shift in fat tissue and turned stored white fat in the mice into brown fat, which burns up more energy and improves metabolic function. Beige or brown fat is a beneficial type of fat that is richly populated with mitochondria, which makes the tissue look brown under a microscope. White fat releases hormonal signals that prompt the storage of still more white fat, but brown fat burns up fat and protects against weight gain, even when caloric intake is high.

In this research, which was published in the journal Nature Communications, mice made obese by a high-fat, high-calorie diet were given the sCG stimulator. These mice not only experienced weight loss, but also showed improved glucose tolerance, reduced insulin levels and decreased the signs of fatty liver, which is a damaging consequence of established obesity. It also even shrunk white fat cells.

In plump mice on the sCG stimulator, circulating dietary fatty acids were increasingly drawn into the brown fat and burned up at high rates. Even muscle and white fat in those mice increased their use of the circulating fatty acids. These metabolic changes caused mice to burn more calories, and their abnormal metabolic function improved.

This new research was led by researchers at the University Hospital in Bonn, Germany, and it elucidated the biochemical pathway that generates brown fat. This brings potential targets into view that could shift white fat into brown fat.

The sCG stimulator used in this study, the authors concluded, “might be used to enhance weight loss induced by physical activity.”

If a drug related to riociguat is to enter broad use for obesity, however, it will need to be cheaper than its close chemical relative. At doses taken by those with pulmonary arterial hypertension, a typical month’s prescription of Adempas costs close to $2,800, or about $90,000 a year.

As a treatment for the nation’s more than 72 million obese adults, that cost could prove prohibitive, especially as obesity and its consequences are increasingly understood to be chronic conditions that will need long-term management.

McMaster Scientists Convert Blood into Neural Cells With One Gene

McMaster University stem cell scientists have discovered a way to adult sensory neurons from human patients simply by having them roll up their sleeve and provide a blood sample. The McMaster scientists directly converted adult human blood cells to both central nervous system (brain and spinal cord) neurons and peripheral nervous system (rest of the body) neurons responsible for pain, temperature and itch perception. This means that how a person’s nervous system cells react and respond to stimuli can be determined from their blood.

This breakthrough was published online recently and was also featured on the cover of the journal Cell Reports. The leader of this research, Mick Bhatia, serves as the director of the McMaster and Cancer Research Institute and holds the Canada Research Chair in Human stem Cell Biology and is a professor in the Department of Biochemistry and Biomedical Sciences in the Michael G. DeGroote School of Medicine.

Scientists do not have a robust understanding of pain and how to treat it. Neurons in the peripheral nervous system is composed of different types of nerves that detect mechanical forces like pressure or touch, and others and detect temperature, such as heat. Pain is perceived by the brain when signals are sent by peripheral pain receptors.

“The problem is that unlike blood, a skin sample or even a tissue biopsy, you can’t take a piece of a patient’s neural system. It runs like complex wiring throughout the body and portions cannot be sampled for study,” said Bhatia.

“Now we can take easy to obtain blood samples, and make the main cell types of neurological systems — the central nervous system and the peripheral nervous system — in a dish that is specialized for each patient,” said Bhatia. “Nobody has ever done this with adult blood. Ever.

“We can actually take a patient’s blood sample, as routinely performed in a doctor’s office, and with it we can produce one million sensory neurons, that make up the peripheral nerves in short order with this new approach. We can also make central nervous system cells, as the blood to neural conversion technology we developed creates neural stem cells during the process of conversion.”

This new protocol uses a gene called “Oct4” to directly reprogram blood cells. Additionally, if two proteins (SMAD and GSK-3) are inhibited with small molecules while the cells are transfected with the Oct4 gene, then the resultant cells transdifferentiate into blood-derived induced neural progenitor cells (BD-iNPCs). Now the direct conversion of skin cells called fibroblasts into neural progenitor cells that look a great like neural crest cells. However, these BD-iNPCs have the ability to differentiate into glial cells (support cells in the nervous system, multiple central nervous system neurons, and pain receptors, which are normally found in the peripheral nervous system.

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Using OCT-4-induced direct reprogramming, Lee et al. convert human blood to neural progenitors with both CNS and PNS developmental capacity. This fate alternation is distinct from fibroblasts that are primed for neural potential. Furthermore, human sensory neurons derived from blood phenocopy chemo-induced neuropathy in formats suitable for drug screening.

This new, revolutionary protocol that directly converts white blood cells into neurons with one gene has not only been patented, but has “broad and immediate applications,” according to Bhatia. He also added that it allows researchers to start asking questions about understanding disease and improving treatments. These cells could be used to determine why certain people feel pain instead of numbness, or whether or not the degree to which people perceive pain is genetically determines, or whether or not diabetic neuropathy ca be mimicked in a culture dish? Bhatia’s new protocol also provides a slick, new model system to find new pain drugs that don’t just numb the perception of pain, but completely block it.

“If I was a patient and I was feeling pain or experiencing neuropathy, the prized pain drug for me would target the peripheral nervous system neurons, but do nothing to the central nervous system, thus avoiding non-addictive drug side effects,” said Bhatia. “You don’t want to feel sleepy or unaware, you just want your pain to go away. But, up until now, no one’s had the ability and required technology to actually test different drugs to find something that targets the peripheral nervous system and not the central nervous system in a patient specific, or personalized manner.”

Bhatia’s team successfully tested their protocol by using fresh blood and frozen blood. This is an important piece of research since blood samples are usually taken and frozen. Freezing blood samples allows scientists or even physicians to create a kind of “time machine” that can show the evolution of a patient’s response to pain over a period of time.

For future studies, Bhatia and his colleagues would like to examine patients with Type 2 Diabetes to determine if his technique can help predict whether they will experience neuropathy by running tests in the lab using their own neural cells derived from their blood sample.

“This bench to bedside research is very exciting and will have a major impact on the management of neurological diseases, particularly neuropathic pain,” said Akbar Panju, medical director of the Michael G. DeGroote Institute for Pain Research and Care, a clinician and professor of medicine.

“This research will help us understand the response of cells to different drugs and different stimulation responses, and allow us to provide individualized or personalized medical therapy for patients suffering with neuropathic pain.”

Stem Cell-Extracted Proteins Promote Bone Regrowth

Scientists from the Gladstone Institutes have found a new technique to regrow bone by using the protein signals produced by stem cells. This new technology could potentially help treat victims who have experienced major trauma to a limb, such as soldiers wounded in combat or casualties of a natural disaster. This new protocol improves older therapies by providing a sustainable source for fresh tissue that also reduces the risk of tumor formation that can arise with stem cell transplants.

This study was published in a journal called Scientific Reports, and it is the first study that successfully extracted bone-producing growth factors from stem cells and showed that these proteins are sufficient to create new bone. This stem cell-based approach was as effective as the current standard treatment in terms of the amount of bone created.

“This proof-of-principle work establishes a novel bone formation therapy that exploits the regenerative potential of stem cells,” says senior author Todd McDevitt, PhD, a senior investigator at the Gladstone Institutes. “With this technique, we can produce new tissue that is completely stem cell-derived and that performs similarly with the gold standard in the field.”

Rather than using stem cells, the Gladstone scientists extracted the proteins that the stem cells secrete, such as a protein called bone morphogenetic protein (BMP). By extracting these proteins, they hoped to harness their regenerative power. McDevitt and his colleagues treated stem cells with a chemical that helped drove them to begin to differentiate into early bone cells. Then they analyzed the secreted factors produced by these cells that signal to other cells to regenerate new tissue. Afterwards, they took these isolated proteins and injected then into mouse muscle tissue to facilitate new bone growth.

Currently, laboratory technicians grind up old bones and extract the available proteins and growth factors that can induce the growth of new bone. Unfortunately, this approach relies on bones taken from cadavers, which are highly variable when it comes to the quality of the available tissue and how much of the necessary signals they still produce. Also, cadaver tissue is not always available.

“These limitations motivate the need for more consistent and reproducible source material for tissue regeneration,” says Dr. McDevitt, who conducted the research while he was a professor at the Georgia Institute of Technology. “As a renewable resource that is both scalable and consistent in manufacturing, pluripotent stem cells are an ideal solution.”

Marrow-Infiltrating Lymphocytes Safely Shrink Multiple Myelomas

Medical researchers at the Johns Hopkins Kimmel Cancer Center have published a report that appeared in the journal Science Translational Medicine in which they describe, for the first time, the safe use of a patient’s own immune cells to treat the white blood cell cancer multiple myeloma. There are more than 20,000 new cases of multiple myeloma and more than 10,000 deaths each year in United States. It is the second most common cancer originating in the blood.

The procedure under investigation in this study is called utilizes a specific type of tumor-targeting T cells, known as marrow-infiltrating lymphocytes (MILs). “What we learned in this small trial is that large numbers of activated MILs can selectively target and kill myeloma cells,” says Johns Hopkins immunologist Ivan Borrello, M.D., who led the clinical trial.

According to Borrello, MILs are the foot soldiers of the immune system that attack invading bacteria or viruses. Unfortunately, they are typically inactive and too few in number to have a measurable effect on cancers.

Experiments conducted is Borrello’s laboratory and in the laboratory of competing and collaborating scientists have shown that when myeloma cells are exposed to activated MILs in culture, these cells could not only selectively target the tumor cells, but they could also effectively destroy them.

To move this procedure from the laboratory into the clinic, Borrello and his collaborators enrolled 25 patients with newly diagnosed or relapsed multiple myeloma. Only 22 were able to receive this new treatment, however.

The Hopkins team extracted and purified MILs from the bone marrow of each patient and grew them in the laboratory to increase their numbers. Then they activated the MILs by exposing them to microscopic beads coated with immune activating antibodies. These antibodies bind to specific cell surface proteins on the MILs that induce profound changes in the cells. This induction step wakes the MILs up and readies them to sniff out tumor cells. These laboratory-manipulated MILs were then intravenously injected back into each patient (each of the 22 patients with their own cells). Three days before these injections of expanded MILs, all patients received high doses of chemotherapy and a stem cell transplant, which are standard treatments for multiple myeloma.

One year after receiving the MILs therapy, 13 of the 22 patients had at least a partial response to the therapy (their cancers had shrunk by at least 50 percent) Seven patients experienced at least a 90 percent reduction in tumor cell volume and lived and average of 25.1 months without cancer progression. The remaining 15 patients had an average of 11.8 progression-free months following their MIL therapy. None of the participants experienced serious side effects from the MIL therapy.

According to Borrello, several U.S. cancer centers have conducted similar experimental treatments (adoptive T cell therapy). However, only this Johns Hopkins team has used MILs. Other types of tumor-infiltrating cells can be used for such treatments, but Borrello noted that these cells are usually less plentiful in patients’ tumors and may not grow as well outside the body.

In nonblood-based tumors, such as melanoma, only about half of those patients have T cells in their tumors that can be harvested, and only about one-half of those harvested cells can be grown. “Typically, immune cells from solid tumors, called tumor-infiltrating lymphocytes, can be harvested and grown in only about 25 percent of patients who could potentially be eligible for the therapy. But in our clinical trial, we were able to harvest and grow MILs from all 22 patients,” says Kimberly Noonan, Ph.D., a research associate at the Johns Hopkins Universithttp://www.fiercevaccines.com/special-reports/gvax-pancreasy School of Medicine.

This small trial helped Noonan and her colleagues learn more about which patients may benefit from MILs therapy. As an example, they were able to determine how many of the MILs grown in the lab were specifically targeted to the patient’s tumor and whether they continued to target the tumor after being infused. They also found that patients whose bone marrow before treatment contained a high number of certain immune cells, known as central memory cells, also had better response to MILs therapy. Patients who began treatment with signs of an overactive immune response did not respond as well.

Noonan says the research team has used these data to guide two other ongoing MILs clinical trials. Those studies, she says, are trying to extend anti-tumor response and tumor specificity by combining the MILs transplant with a Johns Hopkins-developed cancer vaccine called GVAX and the myeloma drug lenalidomide, which stimulates T cell responses.

These trials also have elucidated new ways to grow the MILs. “In most of these trials, you see that the more cells you get, the better response you get in patients. Learning how to improve cell growth may therefore improve the therapy,” says Noonan.

Kimmel Cancer Center scientists are also developing MILs treatments to address solid tumors such as lung, esophageal and gastric cancers, as well as the pediatric cancers neuroblastoma and Ewing’s sarcoma.

Mesoblast Phase Degenerative Disc Disease Treatment Receives Positive Feedback from European Regulatory Agencies

Mesoblast Limited announced that European Medicines Agency has approved expansion of their Phase 3 clinical program of its product candidate MPC-06-1D for degenerative disc disease.

Mesoblast’s Phase 3 program for this product candidate is currently in the process of enrolling patients in the United States under an Investigational New Drug (IND) application filed with the US Food and Drug Administration (FDA).  Having received general agreement from EMA on the target patient population, trial size, primary composite endpoint, and comparators in the control population, Mesoblast now intends to additionally enroll patients across multiple European sites.

The discussions with EMA occurred as part of combined scientific and reimbursement advice under an EU pilot program known as Shaping European Early Dialogues (SEED). The SEED pilot program was established to facilitate early dialogue between EMA, European Health Technology Assessment reimbursement bodies, and selected companies with late-stage clinical development programs. Mesoblast’s product candidate MPC-06-ID is one of only seven medicines accepted for the SEED program.

Mesoblast and SEED representatives discussed key clinical trial aspects of the development of MPC-06-ID including the safety database, mechanisms of action, patient population and trial size, composite endpoints, and comparators. The discussions also focused on access to EU markets and pharmacoeconomic endpoints that may lead to reimbursement.

The guidance from the meeting with SEED representatives may result in a final comprehensive EU development and commercialization program that has an increased likelihood of producing data that will be acceptable for both registration and reimbursement review in multiple European countries.

Two Genes Control Breast Cancer Stem Cell Proliferation and Tumor Properties

When mothers breastfeed their babies, they depend upon a unique interaction of genes and hormones to produce milk and deliver it to their hungry little tyke. Unfortunately, this same cocktail of genes and hormones can also lead to breast cancer, especially if the mother has her first pregnancy after age 30.

A medical research group at the Medical College of Georgia at Georgia Regents University has established that a gene called DNMT1 plays a central role in the maintenance of the breast (mammary gland) stem cells that enable normal rapid growth of the breasts during pregnancy. This same gene, however, can also maintain those cancer stem cells that enable breast cancer. According to their work, the DNMT1 gene is highly expressed in the most common types of breast cancer.

Also, another gene called ISL1, which encodes a protein that puts the brakes on the growth of breast stem cells, is nearly silent in the breasts during pregnancy and in breast cancer stem cells.

Dr. Muthusamy Thangaraju, a biochemist at the Medical College of Georgia, who is the corresponding author of this study, which was published in the journal Nature Communications, said, “DNMT1 directly regulates ISL1. If the DNMT1 expression is high, this ISL1 gene is low.” Thangaraju and his team first observed the connection between DNMT1 and ISL1 when they knocked out the DNMT1 gene mice and noted an increase in the expression of ISL1. These results inspired them to examine the relationship of these two genes in human breast cancer cells.

Thangaraju and his co-workers discovered that ISL1 is silent in most human breast cancers. Furthermore, they demonstrated that restoring higher levels of ISL1 to human breast cancer cells dramatically reduced cancer stem cell populations, the growth of these cells, and their ability to spread throughout the tissue; all of which are hallmarks of cancer.

Conversely, Thangaraju and his team knocked out the DNMT1 gene in a breast-cancer mouse model, the breast will not develop as well. However, according to Thangaraju, this same deletion will also prevent the formation of about 80 percent of breast tumors. In fact, DNMT1 also down-graded super-aggressive, triple-negative breast cancers, which are negative for the estrogen receptor (ER-), progesterone receptor (PR-), and HER2 (HER2-).

The findings from this work also point toward new therapeutic targets for breast cancer and new strategies to diagnose early breast cancer. For example, a blood test for ISL1 might provide a marker for the presence of early breast cancer. Additionally, the anti-seizure medication valproic acid is presently being used in combination with chemotherapy to treat breast cancer, and this drug increases the expression of ISL1. This might explain why valproic acid works for these patients, according to Thangaraju. Workers in Thangaraju’s laboratory are already screening other small molecules that might work as well or better than valproic acid.

Mammary stem cells maintain the breasts during puberty as well as pregnancy, which are both periods of dynamic breast cell growth. During pregnancy, breasts may generate 300 times more cells as they prepare for milk production. Unfortunately, these increased levels of cell growth might also include the production of tumor cells, and the mutations that lead to breast cancer increase in frequency with age. If the developing fetus dies before she comes to term, immature breast cells that were destined to become mature mammary gland cells can more easily become cancer, according to Rajneesh Pathania, a GRU graduate student who is the first author of this study.

DNMT1 is essential for maintaining a variety of stem cell types, such as hematopoietic stem cells, which produce all types of blood cells. However, the role of DNMT1 in the regulation of breast-specific stem cells that make mammary gland tissue and may enable breast cancer has not been studied to this point.

For reasons that unclear, there is an increased risk of breast cancer if the first pregnancy occurs after age 30 or if mothers lose their baby during pregnancy or have an abortion. Women who never have children also are at increased risk, but multiple term pregnancies further decrease the risk, according to data compiled and analyzed by the American Cancer Society.

Theories to explain these phenomena include the coupling of the hormone-induced maturation of breast cells that occurs during pregnancy with an increase in the potential to produce breast cancer stem cells. Most breast cancers thrive on estrogen and progesterone, which are both highly expressed during pregnancy and help fuel stem cell growth. During pregnancy, stem cells also divide extensively and as their population increases, DNMT1 levels also increase.

In five different types of human breast cancer, researchers found high levels of DNMT1 and ISL1 turned off. Even in a laboratory dish, when they reestablished normal expression levels of ISL1, human breast cancer cells and stem cell activity were much reduced, Thangaraju said.

Skull Suture Stem Cells Can Heal Birth Defect and Facial Injuries

A research group from the University of Southern California (USC) School of Dentistry have identified a new stem cell population that is responsible for a particular birth defect and might someday help treat wounded soldiers, accident victims and other patients recover from disfiguring facial injuries.

“This has a lot more implication than what we initially thought,” said Yang Chai, a lead researcher on the study at the Herman Ostrow School of Dentistry of USC. “We can take advantage of these stem cells not only to repair a birth defect, but to provide facial regeneration for veterans or other people who have suffered traumatic injury.”

According to Chai, treatments of human patients that utilize the new stem cell population he and his colleagues identified could become available within the next five to 10 years, but it must pass through the intense hurdles of clinical trials with human patients.

In their mouse studies, Chai and his team noticed a stem cell population that expresses the transcription factor Gli1+. These Gli1+ stem cells appear within the tissues that eventually fuse the craniofacial bones together. However, in mice that have a shortage or even absence of the Gli1+ stem cells, the skull bones prematurely fused together to cause “craniosynostosis,” a birth defect that locks the skull into a small structure can cannot accommodate the growing brain and can hinder brain development. Chai and his colleagues also found that these Gli+ stem cells are activated when the skull is injured. Therefore, they transplanted Gli1+ stem cells into injured mice, and within weeks, it was clear that the Gli1+ stem cells had migrated to the injured parts of the skull and were repairing those damaged areas.

“It is a very minimal procedure to just cut off a strip of bone instead of cutting the entire calvaria [skull-cap],” Chai said. A stem cell treatment “will truly restore the normal anatomy, which will then be able to respond to the continuous brain growth and the patient can live a normal life.”

These findings also have upset the bone development apple cart, according to Hu Zhao, the first author of this publication. “Before our findings, people just assumed the bones all around the body are the same,” Zhao said. “We are now showing that they are all totally different, that they have a different source of stem cells and a different healing mechanism.”

The discovery of these Gli1+ stem cells and their ability to regenerate craniofacial injuries might mean that physicians will be able to use them to treat people who have suffered disfiguring facial injuries and infants diagnosed with craniosynostosis through biological means instead of multiple, high-risk surgeries.

Presently, the surgeons, unknowingly, were destroying the regenerative stem cells that could potentially help the patient when they operated on craniosynostosis patients. During a typical craniosynostosis surgery, doctors break the skull into multiple pieces, staple them together and then discard the suture tissues as waste. Zhao said the procedure, intended to aid brain growth, actually interferes with healing because the Gli1+ stem cells are lost.

According to Chai, a biological approach that transplants Gli1+ stem cells into targeted areas could give infants with craniosynostosis the flexibility that they need for their brains to grow normally. For those patients who have suffered head trauma or facial disfigurement, the Gli1+ stem cells could repair fractured or injured areas.

Chai acknowledges the need to conduct additional experiments before such a treatment is tested in clinical trials with patients.

“One of our ideas is that we could probably use those healthy sutures and the healthy pieces from them and transplant them on the injured sides,” Zhao said.

The Isolation of Dental Stem Cell Lines and How They Repair Teeth

Research teams at INSERM and Paris Descartes University have isolated dental stem cell lines and detailed the natural mechanism by which such cells repair lesions in teeth. This discovery could provide the foundation for therapeutic strategies that mobilize resident dental stem cells and amplify their intrinsic capacity for repair.

Teeth are mineralized organs that are anchored within the gums by roots. The outermost layer of the tooth is the enamel, which is one of the hardest substances in the body. Beneath the enamel is the dentine (sometimes known as the ivory), and the dentin (dentine if you are British) is filled with microscopic tubes that radiate from the inner pulp to the surface. These dentinal tubules contain cells called odontoblasts, which are the cells that made the dentin in the first place, and dentinal fluid (contains a mixture of albumin, transferrin, tenascin and proteoglycans). The odontoblasts maintain the dentin, but as we age, the dentin tubules calcify. Dentin is a yellowish, bone-like matrix that is porous. It is softer than enamel and decays more rapidly and is subject to severe cavities if not properly treated. Beneath the dentin is the pulp, which contains blood vessels and nerves and also houses a resident stem cell population.

Tooth Anatomy

When a dental lesion appears, the dormant stem cells in the pulp awaken and try to repair the tooth, but the means by which these cells do this is unknown.

To address these gaps in our knowledge, researchers from INSERM (French Institute of Health and Medical Research or Institut national de la santé et de la recherche), and the Paris Descartes University have extracted and isolated dental stem cells from the pulp of mouse molars and analyzed them further.

In the midst of their characterization of these cells, the French teams discovered that these dental pulp stem cells possess five different cell surface receptors for the neurotransmitters dopamine and serotonin. The present of these receptors suggested that the response of dental pulp stem cells to tooth injury was mediated by these neurotransmitters. Blood platelets, for example, are activated by binding serotonin and dopamine. Could these dental be activated by similar means?

The first set of experiments examined tooth repair in mice that lacked platelets that produced serotonin or dopamine. Such mice failed to repair tooth lesions, suggesting that serotonin and dopamine are important to inducing stem cell-mediated tooth repair.

Next, these laboratories characterized these five receptors and found that four of them were intimately involved in tooth repair; knocking out any one of the would abrogate tooth repair responses.

“In stem cell research, it is unusual to be simultaneously able to isolate cell lines, identify the markers that allow them to be recognized (here the receptors), discover the signal that recruits them (serotonin and dopamine), and discover the source of that signal (blood platelets). In this work, we have been able, unexpectedly, to explore the entire mechanism,” said Odile Kellermann, the principal author of this work.

Dentists use pulp capping materials like calcium hydroxide and tricalcium phosphate-based biomaterials to repair the tooth and fill lesions. These new findings, however, could produce new therapeutic strategies aimed at mobilizing the resident dental pulp stem cells to magnify the natural reparative capacity of teeth without the use of replacement materials.

One Type of Lung Cell Can Regenerate Another

A collaboration between the Perelman School of Medicine at the University of Pennsylvania and Duke University has found that lung tissue has a much great ability to regenerate than previously thought.

Lungs contain thousands of tiny clusters of sacs called alveoli. Gas-exchange between the air and our blood stream occurs across the thin lining of the alveoli, which are lined with extensive networks for diminutive blood vessels called capillaries. The cells that form the paper-thin lining of the alveoli are called type 1 cells. Within the alveoli are cells called type 2 cells, which secrete surfactant; a soapy substance that prevents the alveoli from collapsing upon themselves when we exhale. Some premature babies do not make enough surfactant and must be treated with surfactant to help them breathe.

Work in mice demonstrated that both type 1 and type 2 cells descend from a common embryonic precursor during lung development. When mice had bits of their lungs removed, labeling studies established that the newly re-established type 2 cells were made from type 1 cells and that some of the newly made type 1 cells were formed from type 2 cells. These results were confirmed by cell culture experiments that grew single type 1 or type 2 lung cells in culture; in both cases, the cultures gave rise to mixed cultures consisting of both type 1 and type 2 lung cells. These data demonstrate that type 1 lung cells can give rise to type 2 lung cells and visa versa.

Previously, the Duke University term had demonstrated that type 2 lung cells in mice not only produce surfactant, but also function as progenitors for other lung cells in adult mice. This shows that type 2 lung cells can definitely differentiate into type 1 lung cells. However, there was no evidence that type 1 lung cells could give rise to other types of lung cells.

In this present work, however, lung injury in mice stimulated the type 1 cells to divide and differentiate into type 2 cells over a period of three weeks while the lung regenerated. According to Jonathan Epstein from the University of Pennsylvania, It’s as if the lung cells can regenerate from one another as needed to repair missing tissue, suggesting that there is much more flexibility in the system than we have previously appreciated. These aren’t classic stem cells that we see regenerating the lung. They are mature lung cells that awaken in response to injury. We want to learn how the lung regenerates so that we can stimulate this process in situations where it is insufficient, such as in patients with COPD (chronic obstructive pulmonary disease).”

This is one of the first studies to demonstrate that mature cells that were thought to be completely at the end of their growth and differentiation capabilities can revert to an earlier state under the right conditions without the use of transcription factors, but by responding to damage.

These two research teams are also applying the approaches outlined in this publication to cells from other tissues, such as the intestine and skin, in order to study the mechanisms of cell maintenance and differentiation, and then relate these same mechanisms back to the heart. They also hope to apply these findings in clinical settings for patients who suffer from idiopathic pulmonary fibrosis, acute respiratory distress syndrome and other such conditions where the alveoli cannot supply sufficient amounts of oxygen to the blood.

Allogeneic Stem Cell Transplantation [9.2]

Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Allogeneic Stem Cell Transplantation

Larry H. Bernstein, MD, FCAP, Writer and Curator


9.2 Allogeneic Stem Cell Transplantation

9.2.1 Allogeneic Stem Cell Treatment


Allogeneic stem cell transplantation involves transferring the stem cells from a healthy person (the donor) to your body after high-intensity chemotherapy or radiation.

Allogeneic stem cell transplantation is used to cure some patients who:

  • Are at high risk of relapse
  • Don’t respond fully to treatment
  • Relapse after prior successful treatment

Allogeneic stem cell transplantation can be a high-risk procedure. The high-conditioning regimens are meant to severely or completely impair your ability to make stem cells and you will likely experience side effects during the days you receive high-dose conditioning radiation or chemotherapy. The goals of high-conditioning therapy are to:

treat the remaining cancer cells intensively, thereby making a cancer recurrence less likely
inactivate the immune system to reduce the chance of stem cell graft rejection

View original post 7,485 more words

Stem Cells Inc Spinal Cord Injury Trial Shows Sustained Improvements in Sensory Function

A cellular therapeutic company known as Stem Cells, Incorporated has been carrying out a Phase I/II clinical trial that was specifically designed to assess both safety and preliminary efficacy of their proprietary HuCNS-SC cells as a treatment for chronic spinal cord injury. Recently, Dr. Armin Curt, the principal investigator of this clinical trial, presented a summary of the safety and preliminary efficacy data from this Phase I/II study at the 4th Joint International Spinal Cord Society (ISCoS) and American Spinal Injury Association (ASIA) meeting which was held in Montreal, Canada.

Spinal cord injury patients are classified by a system that was developed by the American Spinal Injury Association (ASIA) and uses grades A through E on the American Spinal Injury Association Impairment Scale (AIS) to indicate the severity of the spinal cord injury. AIS Grade A injuries consist of a loss of all spinal cord function (sensation and movement) below the level of injury is lost. This is known as a complete injury. All the other AIS grades are considered incomplete. Patients with Grade B injuries have some sensation below the level of injury, but there is no movement below the injury.. In patients with AIS Grade C injuries, there is both sensation and movement, but most of the muscles below the injury cannot function against resistance and that includes gravity. Those with AIS Grade D spinal cord injuries have some sensation and movement, but more than half of the muscles below the injury can function against resistance. Finally those with AIS Grade E injuries have both normal sensation and movement, but there may be other signs of injury, for example, pain.

For this trial, Stem Cell Inc enrolled 12 subjects who had suffered from a severe spinal cord injury at the thoracic or chest level (T2-T11); seven AIS A and 5 AIS B patients.. In order to qualify for this study, all patients had to be classified as either AIS A or B and a minimum of 3 months from injury.

The trial involved internationally prominent medical centers for spinal cord injury and rehabilitation, and associated principal investigators; Dr. Armin Curt at the University of Zurich and Balgrist University Hospital, Dr. Steve Casha at the University of Calgary, and Dr. Michael Fehlings at the University of Toronto.

All subjects in this trial received HuCNS-SC cells by means of direct transplantation into the spinal cord and they were also treated, temporarily, with immunosuppressive drugs to prevent the immune system from rejecting the implanted cells. Patients were regularly evaluated for safety of the treatment protocol, and to determine if patients showed any change in neurological function. To determine this, patients were given a standard battery of movement and sensory tests before the surgery and at routine intervals after the procedure. Thus all patients were simultaneously enrolled in a safety evaluation and separate evaluation that tested the efficacy of the procedure as well.

In the safety analyses of these subjects, all the data demonstrated that the surgical transplantation technique and cell dose were safe and well tolerated by all patients. HuCNS-SC cells were injected directly into the spinal cord both above and below the level of injury and none of the patients in sequential examinations over the course of twelve months showed any abnormal changes in spinal cord function associated with the transplantation technique. Additionally, there were no adverse events that could be attributed to the HuCNS-SC cells.

Analyses of the functional data after twelve-months revealed sustained improvements in sensory function that emerged consistently around three months after transplantation and persisted until the end of the study. These gains in sensory function involved multiple sensory pathways and were observed more frequently in the patients with less severe spinal cord injuries. Three of the seven AIS A patients and four of the five AIS B patients showed signs of positive sensory gains. Two patients in the study progressed from AIS A, to the lesser degree of injury grade, AIS B.

“It has been a privilege to be a part of the first study to test the potential of neural stem cell transplantation in thoracic spinal cord injury,” said Dr. Armin Curt, Professor and Chairman of the Spinal Cord Injury Center at Balgrist University Hospital, University of Zurich. “The gains we have detected indicate that areas of sensory function have returned in more than half the patients. Such gains are unlikely to have occurred spontaneously given the average time from injury. This patient population represents a form of spinal cord injury that has historically defied responses to experimental therapies, and the measurable gains we have found strongly argue for a biological result of the transplanted cells. These gains are exciting evidence that we are on the right track for developing this approach for spinal cord injury. This early outcome in thoracic injury firmly supports testing in cervical spinal cord injury.”

Stephen Huhn, M.D., FACS, FAAP, Vice President, Clinical Research and CMO at StemCells, Inc., said, “This research program has the potential to revolutionize the therapeutic paradigm for spinal cord injury patients. The clinical gains observed in this first study are a great beginning. We found evidence of sensory gains in multiple segments of the injured thoracic spinal cord across multiple patients. Our primary focus in this study for spinal cord injury was to evaluate safety and also to look for even small signs of an effect that went beyond the possibility of spontaneous recovery. We are obviously very pleased that the pattern of sensory gains observed in this study are both durable and meaningful, and indicate that the transplantation has impacted the function of damaged neural pathways in the cord. The Company’s development program has now advanced to a Phase II controlled study in cervical spinal cord injury where the corollary of sensory improvements in thoracic spinal cord injury could well be improved motor function in the upper extremities of patients with cervical spinal cord injuries.”

CAR T-Cell Therapy Surpasses 90% Complete Remission Rate in Pediatric ALL

The chimeric antigen receptor (CAR) T-cell therapy JCAR017 elicited a 91% complete remission rate in pediatric patients with relapsed/refractory acute lymphoblastic leukemia (ALL), according to results from a phase I trial presented at the 2015 AACR Annual Meeting.

In the treated patients, complete remissions were observed in 20 of 22 patients, as ascertained by flow cytometry.  Complete remissions were observed with all applied doses of JCAR017 and in patients who had been treated already with CD19-targeted therapies.  Severe neurotoxicity and/or severe “cytokine release syndrome” was observed in 8 patients. In total, 4 patients have relapsed—only one of which had CD19-positive disease.

“The 91% remission rate in this phase I study of JCAR017 is highly encouraging, particularly when considering these pediatric patients failed to respond to standard treatments,” Michael Jensen, MD, said in a statement. “Based on these results we are eager to advance this study, and to continue advancing the use of cell therapies to change how we treat cancer and provide patients the opportunity for better treatment options.”

Jensen serves as the director of the Ben Towne Center for Childhood Cancer Research at Seattle Children’s Research Institute, and is also the scientific co-founder of Juno Therapeutics, which is the company that is developing JCAR017.  JCAR017 is being evaluated in an ongoing phase I/II study for pediatric and young adult patients with relapsed/refractory CD19-positive leukemia at the Seattle Children’s Hospital.

This  study intends to enroll 80 patients.  The phase I portion enrolled patients who had undergone an allogeneic hematopoietic cell transplant, but the second phase of the study is open to patients, regardless of prior transplant status (NCT02028455).

“Given the impressive clinical results with this defined cell product candidate, we are encouraged to begin testing of JCAR017 in adult patients with B cell malignancies, including non-Hodgkin lymphoma, later this year,” Hans Bishop, chief executive officer of Juno Therapeutics, said in a statement.

Juno also has three other CAR and T cell receptor therapies that are under evaluation in clinical trials.  The furthest along is JCAR015, which received a breakthrough therapy designation from the FDA as a treatment for patients with relapsed or refractory B-cell ALL in November 2014.  In one trial, JCAR015 is being used to treat precursor B cell ALL, which is the condition for which JCAR015 was awarded its orphan drug designation (NCT01840566).  In a second trial, patients with relapsed/refractory aggressive B cell non-Hodgkin lymphoma (NHL) are being treated with high dose therapy and autologous stem cell transplantation followed by infusion of JCAR015 (NCT01044069).

There are plans for future clinical trials to explore Juno’s CAR T cell therapies in combination with immune checkpoint inhibitors. Recently, Juno and MedImmune, the biologics research and development arm of AstraZeneca, announced an agreement focused on the clinical development of combination strategies.  A jointly-funded phase Ib study will explore one of Juno’s CD19-directed CAR T cell therapies in combination with the PD-L1 inhibitor MEDI4736 as a treatment for patients with NHL.  It is expected to begin later this year.

“We believe combination strategies such as this will help us better understand the full potential of our engineered T cell platform in both hematological and solid tumor settings,” Mark W. Frohlich, MD, executive vice president, Research & Development, Juno Therapeutics, said in a statement.

MEDI4736 is currently under evaluated in phase III clinical trials that are testing MEDI4736 alone and in combination with the CTLA-4 antibody tremelimumab in patients with a variety of non-small cell lung cancers and in patients with head and neck cancer who have failed prior chemotherapy.

Competition in the field of immuno-oncology has resulted in collaborations between several pharmaceutical companies, outside of the Juno deal. This is evident in the field of CAR-modified T-cell therapy, where collaborations exist between Novartis and the University of Pennsylvania (CTL019) and between Kite Pharma and the NCI (KTE-C19).

In the pediatric oncology space, results from the breakthrough therapy CTL019 were presented at the 2014 ASH Annual Meeting and demonstrated similar findings to those announced for JCAR017. In this phase I trial of 39 pediatric patients with relapsed/refractory ALL, CTL019 demonstrated a 92% complete remission rate. In total, 85% of patients who achieve a complete remission tested MRD-negative by flow cytometry.

Making Platelets in the Culture Dish

Bone marrow-based cells known as megakaryocytes are rather uncommon in bone marrow, but these cells are very important for the health and daily operation of the human body. Megakaryocytes, you see, produce platelets, which are critical to clotting broken blood vessels and wound healing. Generating megakaryocytes in cell culture has proven to be rather difficult, but induced pluripotent stem cells might provide a way to make megakaryocytes in culture.



The differentiation of induced pluripotent stem cells (iPSCs) into megakaryocytes could potentially create a renewable cell source of platelets for treating patient with “thrombocytopenia,” which is a deficiency of platelets. Zack Wang and his colleagues from Johns Hopkins University in Baltimore, Maryland have developed a protocol to make megakaryocytes in culture from iPSCs. However, more than that, Wang and his co-workers wanted to make patient-specific platelets in culture without using any animal products and with compounds that were approved by the US Food and Drug Association. Such a protocol would demonstrate that using such cells in human patients is feasible and safe.

Wang and his colleagues developed an efficient system that generated megakaryocytes from human iPSCs without the use of animal feeder cells and without animal products (known as xeno-free condition). Several crucial reagents necessary to differentiate iPSCs into megakaryocytes into were replaced with Food and Drug Administration-approved pharmacological reagents that included romiplostim (Nplate, a thrombopoietin analog), oprelvekin (recombinant interleukin-11), and Plasbumin (human albumin). Wang and his group used their method to induce megakaryocytes generation from human iPSCs derived from 23 individuals in two steps: 1) generation of CD34+CD45+ hematopoietic progenitor cells (HPCs) for 14 days; and 2) generation and expansion of CD41+CD42a+ megakaryocytes from HPCs for an additional 5 days. After 19 days, Wang and his group observed abundant CD41+CD42a+ megakaryocytes that also expressed the megakaryocyte-specific cell-surface proteins CD42b and CD61. These cells were also polyploid, which means that they had multiple copies of each chromosome rather than just 2 copies (≥16% of derived cells with DNA contents >4N). Gene expression studies showed that megakaryocytic-related genes were highly expressed in their cultured megakaryocytes.

Characterization of human induced pluripotent stem cell-derived MKs. (A): Representative images of CFU-MK colonies taken from D14 (upper) and D19 (lower) suspension cells. All the colonies containing at least 50 CD41+ cells were considered CFU-MKs. (B): The number of CFU-MK colonies from 1.5 × 105 isolated CD34+ cells on days 14 and 19. The colonies were counted after 12 days of culture from one 35-mm dish. Mean ± SD; n = 3; ∗∗, p < .01. (C): DNA content analysis by flow cytometry on day 19. Left: The whole population stained by propidium iodide. Right: Double staining using CD41-APC and DAPI, gated on CD41+ population. (D): Wright-Giemsa staining of the suspension cells on day 19. Scale bars = 100 μm. Abbreviations: CFU, colony-forming unit; D, day; MKs, megakaryocytes.
Characterization of human induced pluripotent stem cell-derived MKs. (A): Representative images of CFU-MK colonies taken from D14 (upper) and D19 (lower) suspension cells. All the colonies containing at least 50 CD41+ cells were considered CFU-MKs. (B): The number of CFU-MK colonies from 1.5 × 105 isolated CD34+ cells on days 14 and 19. The colonies were counted after 12 days of culture from one 35-mm dish. Mean ± SD; n = 3; ∗∗, p < .01. (C): DNA content analysis by flow cytometry on day 19. Left: The whole population stained by propidium iodide. Right: Double staining using CD41-APC and DAPI, gated on CD41+ population. (D): Wright-Giemsa staining of the suspension cells on day 19. Scale bars = 100 μm. Abbreviations: CFU, colony-forming unit; D, day; MKs, megakaryocytes.

This protocol could be used to further understand the medical conditions that lead to thrombocytopenia. Deeper understanding of these medical conditions will hopefully lead to better treatments of them. Also, Wang’s protocol may lead to the generation of large numbers of platelets in culture that could then be given to patients who need them.

Using Peptides to Reset a Diseased Cell

Researchers at the University of California, San Diego School of Medicine have published a series of proof-of-concept experiments that demonstrate the ability to direct medically relevant cell behaviors by artificially manipulating a central hub in cell communication networks. The manipulation of this communication node, which was reported in the journal Proceedings of the National Academy of Sciences, makes it possible to reprogram major parts of a cell’s signaling network instead of targeting only a single receptor or cell signaling pathway.

This discovery could have tremendous clinical value, since it could slow or reverse the progression of diseases, such as cancer, which are driven by abnormal cell signaling along a variety of signaling pathways.

“Our study shows the feasibility of targeting a hub in the cell signaling network to reset aberrant cell signaling from multiple pathways and receptors,” said senior author Pradipta Ghosh, MD, an associate professor of medicine.

The UC San Diego team engineered two small protein fragments, known as peptides, to either turn on or turn off the activity of a family of proteins called G proteins. G protein-coupled receptors, which are embedded into the surfaces of cells, are used by cells to sense and respond to their environments. Approximately 30 percent of all prescription drugs target cells by binding to and affecting G protein-coupled receptors.

G protein coupled receptor cycle

Several laboratories, including those at UC San Diego, have discovered that G proteins can also be activated inside cells, and not simply on cell surfaces. Other receptors can activate the internal components of the G protein-coupled receptor, as can a protein called GIV. GIV has been implicated in cancer metastasis and other disease states. Both the “on” and “off” peptides were made from parts of the GIV protein receptor.

In a series of cell culture experiments, the “on” peptides were shown to accelerate the ability of the cells to migrate after scratch-wounding, which is a process linked to wound healing. The “off” peptide, in contrast, reduced the aggressiveness of cancer cells and decreased the production of collagen by cells associated with liver fibrosis. In experiments with mice, the topical application of the “on” peptides helped skin wounds heal faster.

“The takeaway is that we can begin to tap an emerging new paradigm of G protein signaling,” Ghosh said.

New Type of Stem Cell Discovered by Salk Scientists

Stem cell scientists from the laboratory of Juan Carlos Izpisua Belmonte at the Salk Institute for Biological Studies in La Jolla, California have discovered a new type of stem cell that could potentially provide a model system for early human development, and might even allow human organs to be grown in large animals for therapeutic purposes.


Izpisua Belmonte and his colleagues came across these types of cells somewhat serendipitously while transplanting human pluripotent stem cells into mouse embryos.


Other types of pluripotent stem cells have already been well-known to stem cell scientists for some time. Stem cells are “pluripotent,” if they have an intrinsic ability to differentiate into any adult cell type. Embryonic stem cells (ESCs), for example, are derived from early human embryos that have yet to implant into the inner layer of the uterus.  However, epiblast stem cells (EpiSCs) have been established from post-implantation embryos and have different properties.  While both are pluripotent, they bear striking differences in molecular signature, signalling dependency, colony morphology, cloning efficiency, metabolic requirements and epigenetic features (see Nichols, J. & Smith, A. Cell Stem Cell 4, 487492 (2009) and Zhou, W. et al. EMBO J. 31, 21032116 (2012)).  Both of these cells have the ability to re-enter embryogenesis but they do so at different developmental time points (pre-implantation versus post-implantation, respectively), which distinguish ESCs and EpiSCs.  Therefore, these two cell types exist in two temporally distinct pluripotent states.  Even though these two types of pluripotent stem cells can be grown into large numbers in the laboratory, differentiating them into specific types of mature, adult cells has proven difficult in some cases. The cells discovered by Izpisua Belmonte and his colleagues are reportedly easier to grow in vitro and engraft into an embryo if they are injected into the right spot. Izpisua Belmonte call these cells “region-selective pluripotent stem cells” (rsPSCs).



Because rsPSCs grow more quickly and stably than other pluripotent cells, they may be more useful for developing new therapies, according to Paul Tesar, a developmental biologist at Case Western Reserve University in Cleveland, Ohio.


Izpisua Belmonte and colleagues originally wanted to transplant various types of human pluripotent stem cells into mouse embryos in the laboratory. They prepared their cells for transplantation by growing them in various blends of culture media that contained different combinations of growth factors and other chemicals. They found that one particular blend was more effective at making the cells grow and proliferate. However, the cells that grew quite well in this concoction displayed different patterns of metabolism and gene expression in comparison to other pluripotent stem cells. These same cells not graft well into the mouse embryo.


Thus, Izpisua Belmonte and his colleagues decided to nail down those features that would cause cells to efficiently integrate into mouse embryos. They injected the human cells into three different regions of a 7.5-day-old mouse embryo. Thirty-six hours later, only those cells that had been grafted into the tail, or posterior of the embryo, integrated and differentiated into the correct cell layers to form a “chimeric” or mixed-tissue embryo. Such organisms contain cells with genomes from DNA organisms. Since these cells seemed to prefer one part of the embryo, Izpisua Belmonte and his team called them region-selective pluripotent stem cells.


From these data, Izpisua Belmonte has proposed that embryos contain multiple types of pluripotent stem cells, including rsPSCs, during their early development. It is not yet clear whether the rsPSCs play a part in designating which part of the embryo will become the head, the middle, or hind end. Identifying various types of pluripotent cells might provide researchers with the ability to study the early stages of human embryonic development by transplanting rsPSCs into animal embryos.


Izpisua Belmonte and his colleagues found that they could easily use enzymes that modify the sequences of DNA to edit the genomes of rsPSCs, which is usually difficult to do in pluripotent cell lines when grown in culture.

Gene editing could help scientists to optimize the ability of human cells to grow within animals, which might allow the creation of transgenic chimeras. Tesar says that the idea of using human pluripotent cells, such as rsPSCs, to create animals with human organs is not unrealistic, but he expects that it will be very difficult. The immune system of the animal might reject the human cells and the growth rates of the two organs might also cause problems.

Izpisua Belmonte’s lab is already starting to implant pig embryos with a different type of stem cells, and this is the only very first step for these techniques.


Gene Therapy/Stem Cell Treatment Cures Boys of Severe Genetic Disease

British doctors have successfully cured youngsters suffering from a deadly inherited genetic disorder using ground-breaking stem cell-based treatments. This is the harbinger of a new era of medicine and genetic therapies.

The young patients who participated in this trial suffer from the most severe form of a rare blood condition call “Wiskott-Aldrich Syndrome.” The trial participants have now been free of the disease for four years.

Patients with Wiskott-Aldrich syndrome are usually male, and they have a deficient immune system that fails to fight off common infections that usually do not affect most people and a reduced ability to form blood clots. The numbers, and size of platelets in the blood, which are the cells responsible for initiating blood clots, are abnormal in individuals with Wiskott-Aldrich syndrome; they have very small platelets and few of them. This condition is called microthrombocytopenia. This platelet abnormality leads to easy bruising or episodes of prolonged bleeding following minor traumas. Additionally, many types of white blood cells are abnormal or nonfunctional, and this increases the risk of several immune and inflammatory disorders. Often patients with Wiskott-Aldrich syndrome develop eczema, which is an inflammatory skin disorder characterized by abnormal patches of red, irritated skin. Affected individuals also have an increased susceptibility to infection, and developing autoimmune disorders. They also have an increased chance of developing some types of cancer, such as cancer of the immune system cells (lymphoma).

Wiskott-Aldrich syndrome is inherited from the X chromosome, and therefore, the condition is much more common in males than in females. Having said that, Wiskott-Aldrich syndrome is still a rather rare condition, with an estimated incidence of 1 – 10 cases per million males worldwide.

Mutations in the WAS gene cause Wiskott-Aldrich syndrome. The WAS gene encodes the WASP protein, which is found in all blood cells, and relays signals from the surface of blood cells to the actin cytoskeleton inside the cell. The actin cytoskeleton is a network of fibrous proteins that compose the cell’s interior structural framework. WASP signaling triggers cell movement and attachment to other cells and tissues. In white blood cells, WASP signaling induces the actin cytoskeleton to establish the interactions between cells and the foreign invaders targeted by them. Mutations in the WAS gene cause a lack of any functional WASP protein, and loss of WASP signaling. Thus white blood cells are less able to respond to foreign invaders, which cause many of the immune problems related to Wiskott-Aldrich syndrome. Similarly, decreased WASP function impairs platelet development, leading to reduced size and early cell death.

In the Britain, Wiskott-Aldrich syndrome affects fewer than one hundred children in Britain, but Daniel Wheeler, 15, of Bristol is one of them. Wheeler was among seven children who participated in the new gene therapy trial at centers in London and Paris.

Daniel was diagnosed with Wiskott-Aldrich syndrome when he was two years old and needed frequent medical care to manage his symptoms which included severe eczema, asthma and inability to fight infections. David’s older brother died from complications associated with the disease. However, since undergoing gene therapy in 2011 Daniel has shown no symptoms and doctors believe he is effectively cured.

Daniel’s mother Sarah, 50, who works in real estate in Bristol said: “Since being around two, Daniel has been in an out of hospital, but now his skin has cleared up and so has his asthma. It means he can get on with his life now.”

Adrian Thrasher, Professor in Pediatric Immunology, at Great Ormond Street Hospital in London, where David’s treatment was carried out, said that it offered new hope for people suffering from incurable disease. “We are entering a new era where genetic treatments are entering mainstream medicine and offering hope to patients for whom conventional treatments don’t work well or are simply unavailable,” he said.

“The work shows that this method is successful in patients who, in the past would have very little chance of survival without a well match bone marrow donor.

“It also excitingly demonstrates the potential for treatment of a large number of other diseases for which existing therapies are either unsatisfactory or unavailable.”

In this trial, David’s bone marrow stem cells were isolated and subjected to gene therapy in the laboratory. The faulty WAS gene was replaced with a healthy copy of the gene. These genetically repaired stem cells were replaced in David’s bone marrow where they began producing healthy blood cells that were free from the disease. Because the healthy blood cells were more durable and lived longer than the diseases ones, they eventually overtook the diseased ones.

Seven children between the ages of eight months and 15 years were selected for the trial because a bone marrow match could not be found. Without bone marrow transplantation, patients usually do not survive their teenage years. All the children had eczema and associated recurrent infections and most experienced severe bleeding and autoimmune disease that, in one case, confined the child to a wheelchair.

The children went from spending an average of 25 days in the hospital to no days in the hospital in the two years after the treatment. Furthermore the child using the wheelchair was able to walk again.

Fulvio Mavilio, Chief Scientific Officer at Genethon, the biotech company which developed the treatment said: “It is the first time that a gene therapy based on genetically modified stem cells is tested in an international clinical trial that shows a reproducible and robust therapeutic effect in different centers and different countries.”

Prenatal Stem Cell Treatment Improves Mobility in Lambs With Spina Bifida

UC Davis fetal surgeon Dr. Diana Farmer has been at the forefront of treating spina bifida in infants while they are still in their mother’s womb. Now, Dr. Farmer and her colleagues have used a large animal model system to study the use of stem cells to improve the clinical outcomes of children who undergo these types of in utero procedures.

Spina bifida is a congenital birth defect that results from abnormal development of the spinal cord. During development, the spinal cord, which beings as a tube (the neural tube), is open at both ends, and these ends eventually close. However, if the posterior opening to the neural tube does not close properly, then the developing spinal cord will have severe structural defects. These structural defects adversely affect the nerves that issue from the spinal cord and spinal bifida can cause lifelong cognitive, urological, musculoskeletal and motor disabilities.

Dr. Farmer’s chief collaborator was another UC Davis science named Aijun Wang, who serves as the co-director of the UC Davis Surgical Bioengineering Laboratory.

“Prenatal surgery revolutionized spina bifida treatment by improving brain development, but it didn’t benefit motor function as much as we hoped,” said Farmer, who serves as chair of the UC Davis Department of Surgery and is the senior author of this study, which was published online in the journal Stem Cells Translational Medicine.

“We now think that when it’s augmented with stem cells, fetal surgery could actually be a cure,” said Wang.

Years ago, Farmer and her colleagues showed in an extensive clinical trial called the Management of Myelomeningocele Study (MOMS) that babies who were diagnosed with spina bifida and were eligible for in utero surgery had better outcomes that babies who underwent surgery after they were born. Babies with spina bifida who were operated on in utero had a better chance of walking, and not needing a shunt to deal with the pressure problems in the brain that some children with spina bifida experience (see N. Scott Adzick, et al., New England Journal of Medicine 2011;364(11):993-1004). Even with this study, the majority of the babies who were treated with in utero surgery were still unable to walk. To improve a baby’s chances of walking, Farmer and her collaborators turned to stem cell treatments.

Farmer and Wang combined fetal surgery with a the transplantation of stem cells from human placentas to improve neurological capabilities of babies born with spina bifida. In children, spina bifida can range from barely noticeable to rather severe. Myelomeningocele is the most common and, unfortunately, the most disabling form of spina bifida. In babies with myelomeningocele, the spinal emerges through the back and usually pulls brain tissue into the spinal column, which causes cerebrospinal fluid to fill the interior of the brain. Therefore, such patients require permanent shunts in their brains in order to drain the extra cerebrospinal fluid.


In this study, lambs with myelomeningocele were operated on in utero in order to return exposed spinal cord tissue into the vertebral column. Then human placenta-derived mesenchymal stromal cells (PMSCs), which have demonstrated neuroprotective qualities (see Yun HM, et al., Cell Death Dis. 2013;4:e958), were embedded in hydrogel and applied to the site of the lesion. A scaffold was placed on top to hold the hydrogel in place, and the surgical opening was closed.

Six of the animals that received the stem cell treatment were able to walk without noticeable disability within a few hours following birth. However, the six control animals that received only the hydrogel and scaffold were unable to stand.

“We have taken a very important step in expanding what MOMS started,” said Wang. “Next we need to confirm the safety of the approach and determine optimal dosing.”

Farmer and Wang will continue their efforts with funding from the California Institute for Regenerative Medicine. With additional evaluation and FDA approval, the new therapy could be tested in human clinical trials.

“Fetal surgery provided hope that most children with spina bifida would be able to live without shunts,” Farmer said. “Now, we need to complete that process and find out if they can also live without wheelchairs.”

How Zebrafish Hearts Regenerate

After a heart attack, the human heart suffers from the loss of heart muscle that has been replaced with a non-contracting scar. Replacing lost heart muscle is something that human hearts do not do terribly well. However the zebrafish heart can easily replace lost cells. New research from Duke University has discovered the properties of the outer layer of the heart known as the epicardium that explains the fish’s incredible ability to regrow heart tissue.

After injury to the heart, the cells in the zebrafish epicardium begin to divide and form new cells that will cover the wound. The epicardial cells also secrete chemicals that prompt muscle cells to grow and divide. These cells also support the production of new blood vessels to carry oxygen to new heart tissues.

The Duke study was published in the May 4 edition of the journal Nature, and reported that when the epicardium is damaged, the entire repair process is delayed until the epicardium heals itself before tending to the rest of the heart. Epicardium-based healing of the heart is dependent on the production of a small, secreted protein called sonic hedgehog. In fact, applying Sonic Hedgehog to the surface of the heart drives the epicardial response to injury.

These results provide a new target to exploit in the quest to help heart patients repair the damage caused by a heart attack, which is a major cause of death and disability in the United States. Over five million Americans are currently in the throes of heart failure, and over 900,000 suffer a heart attack each year.

“The best way to understand how an organ regenerates is to deconstruct it. So for the heart, the muscle usually gets all the attention because it seems to do all the work,” said Kenneth D. Poss, Ph.D., senior author of the study and professor of cell biology at Duke University School of Medicine. “But we also need to look at the other components and study how they respond to injury. Clearly, there is something special about the epicardium in zebrafish that makes it possible for them to regenerate so easily.”

Poss and his coworkers have been studying heart regeneration in zebrafish for the last 13 years. When he worked as a postdoctoral research fellow, he was the first to show that zebrafish could regrow severed pieces of heart tissue. Since that time, his laboratory has found that this regeneration involves the input from the epicardium, that thin layer of cells that covers the heart surface.
“The epicardium is underappreciated, but we think it is important because similar tissues wrap up most of our organs and line our organ cavities,” Poss said. “Some people think of it as a stem cell because it can make more of its own, and can contribute all different cell types and factors when there is an injury. The truth is we know surprisingly little about this single layer of cells or how it works. It is a mystery.”

Poss and his colleagues attempted to identify the characteristics of the epicardium that make it so good at regenerating the heart. Duke postdoctoral fellow Jinhu Wang performed open-heart surgery on live zebrafish, and removed approximately one fifth of the heart muscle. Wang also used genetic tricks to kill off 90 percent of the epicardial cells. Then he measured how well the heart healed at various time points. Wang discovered that removing the epicardium created a clear delay in regeneration, but that regeneration eventually caught up to that of zebrafish with an intact epicardium. Wang’s results suggested that the 10 percent of epicardial cells left were able to rebuild the epicardial layer before moving on to heart muscle.

Intrigued by the finding, Jingli Cao, another postdoctoral fellow in the Poss laboratory, devised a technique to remove hearts from zebrafish and grow them in laboratory culture. In culture, the tiny two-chambered fish hearts continue to beat and behave as if they were still tucked inside the organism.

As before, Cao destroyed most of the epicardial layer of the heart and then they placed the cultured hearts under the microscope every day to capture heart regeneration in action. Cao noticed that the epicardium regenerated rapidly, covering the heart like a wave from the base of one chamber to the tip of the other in just a week or two.

The outer layer of the zebrafish heart (shown in green) is regenerated rapidly after damage, covering the heart like a wave from the base of one chamber to the tip of the other. Researchers have discovered properties of this mysterious outer layer -- known as the epicardium -- that could help explain the aquarium denizen’s remarkable ability to regrow cardiac tissue. Photo credit: Jingli Cao
The outer layer of the zebrafish heart (shown in green) is regenerated rapidly after damage, covering the heart like a wave from the base of one chamber to the tip of the other. Researchers have discovered properties of this mysterious outer layer — known as the epicardium — that could help explain the aquarium denizen’s remarkable ability to regrow cardiac tissue. Photo credit: Jingli Cao

The Poss laboratory then searched for small molecule compounds or drugs that would affect the ability to regenerate. In particular, they screened molecules known to be involved in the development of embryos, like fibroblast growth factors and sonic hedgehog, and discovered that sonic hedgehog was essential for heart regeneration. Poss and others plan to extend such a screen to molecules that could enhance heart repair in zebrafish, and perhaps one day give clues for new treatments in humans with heart conditions.

In a second paper that was published in the April 1, 2015, edition of the journal eLife, Poss and his colleagues found that the epicardium produces a molecule called neuregulin1 that makes heart muscle cells divide in response to injury. When Poss and his coworkers artificially boosted levels of neuregulin1, even without injury, the heart started building more and more heart muscle cells.

“Studies of the epicardium in various organisms have shown that this tissue is strikingly similar between fish and mammals, indicating that what we learn in zebrafish models has great potential to reveal methods to stimulate heart regeneration in humans,” said Poss.

FDA approves Raplixa to help control bleeding during surgery

Spray-on fibrin for surgical use. Very cool.

New Drug Approvals

The U.S. Food and Drug Administration today approved Raplixa (fibrin sealant [human]), the first spray-dried fibrin sealant approved by the agency. It is used to help control bleeding during surgery.

April 30, 2015


The U.S. Food and Drug Administration today approved Raplixa (fibrin sealant [human]), the first spray-dried fibrin sealant approved by the agency. It is used to help control bleeding during surgery.

Raplixa is a biological product approved for use in adults to help control bleeding from small blood vessels when standard surgical techniques, such as suture, ligature or cautery, are ineffective or impractical. When applied to a bleeding site, Raplixa is dissolved in the blood and a reaction starts between the fibrinogen and thrombin proteins. This results in the formation of blood clots to help stop the bleeding.

Raplixa contains fibrinogen and thrombin, two proteins found in…

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Promising New Drug Attacks Cancer Stem Cells in Mesothelioma

The anticancer drug defactnib is currently the subject of clinical trials being conducted in multiple countries. Data from this trial in patients with a type of cancer called mesothelioma have shown that defactnib is potentially quite effective in the treatment of these cancers. Defactnib, which is being marketed by biopharmaceutical company Verastem, Inc.

Mesothelioma attacks the lining of the lung, abdomen and, in some cases, the heart. It has only one known cause; the ingestion or inhalation of asbestos fibers.

This trial is currently in its second phase, and it involves 180 patients in 13 countries. The goal of this trial is to evaluate the ability of Defactnib to kill cancer stem cells that are the main cause of the spread of the tumors and their recurrence. Even though the main focus of this trial has been on treating mesothelioma, positive results have also been achieved by using defactnib to treat other types of cancer as well.

In this trial, mesothelioma patients were treated with a combination of defactnib and pemetrexed for 12 days prior to undergoing surgery. Pemetrexed has been approved by the U.S. Food and Drug Administration to treat mesothelioma. Tumors shrunk in 70 percent of the treated mesothelioma patients. Defactnib is designed to inhibit the activity of a protein called the Focal Adhesion Kinase or FAK. FAK is very important for cancer stem cell function and without it, cancer stem cells cannot grow.

“These and other exciting developments continue to build belief that there may be an end to this horrible disease in sight,” said Russell Budd, president and managing shareholder of the mesothelioma law firm Baron and Budd. “It is extremely encouraging to see signs of progress occur on a regular basis.”