Saturday, 30 November 2013

Finding Hope for Cerebral Palsy: Stem Cell Therapy

Child with Cerebral Palsy being examined
The effects of a debilitating disease like cerebral palsy on a child, as well as the family of that child, are far beyond what words can describe.

Often times, these families are left with few options at the very most in terms of treatment, and have to rely heavily on physical and psychological therapy to try and improve their child’s quality of life.

But are there better treatment options?
In most cases, children born with cerebral palsy experience a loss of general motor skills and have difficulty speaking, which is usually a result of a lack of oxygen to the center portions of the brain that control the movement of the body’s extremities. However, in more extreme cases, mental retardation and a near complete state of disability is often seen.

Friday, 29 November 2013

Human embryonic stem cell lines placed on NIH Stem Cell Registry

Scientists at King’s College London announced a few days ago that 16 human embryonic stem cell lines have been approved by the US National Institutes of Health (NIH) and placed on their Stem Cell Registry, making them freely available for federally-funded research in the USA. 

The stem cell lines, which carry genes for a variety of hereditary disorders such as Huntington’s disease, spinal muscular dystrophy and cystic fibrosis, are considered to be ideal research tools for designing models to understand disease progression, and ultimately in helping scientists develop new treatments for patients.

King’s is now one of the five biggest providers of disease-specific human embryonic stem cells lines on the NIH Registry, and the largest from the UK. The development is a significant milestone for King’s and keeps the university at the forefront of global research into regenerative medicine.

Researchers identify stem cell population responsible for heart regeneration

Some vertebrates seem to have found the fountain of youth, at least when it comes to their heart. In many amphibians and fish, for example, this important organ has a marked capacity for regeneration and self-healing.

There are even some species that have perfected this capability and can completely repair damage caused to heart tissue, thus maintaining the organ's full functionality.

However, up until recently it was widely accepted that the mammalian heart had little to no regenerative capacity. However, scientists now know that heart muscle cells constantly regenerate, although at a very low rate.

Thursday, 28 November 2013

South Carolina lawmaker accused of misbranding stem cells


A freshman South Carolina lawmaker is facing federal charges over the mislabeling of stem cells.

Court records show that 31-year-old Rep. Stephen Goldfinch Jr. was charged Tuesday with one count of misbranded drugs.

Federal prosecutors say the Murrells Inlet Republican owned Caledonia Consulting, a Mount Pleasant company that harvests and processes stem cells from umbilical cord blood.

The government says that between April 2006 and December 2008, Caledonia sold stem cells to a Texas man who performed unapproved procedures involving stem cells.

Researchers at Penn discover mechanism behind the longevity of hematopoietic stem cells

Picture of a dividing blood stem cell. Myosin IIB is
labeled green and is concentrated on the
side that will remain a stem cell.
The blood stem cells that live in bone marrow - called hematopoietic stem cells - are at the top of a complex family tree. Such stem cells split and divide down various pathways that ultimately produce red cells, white cells and platelets. These "daughter" cells must be produced at a rate of about one million per second to constantly replenish the body's blood supply.

Researchers have long wondered what allows these stem cells to persist for decades, when their progeny last for days, weeks or even months before they need to be replaced. Now, a new study by researchers at the University of Pennsylvania has uncovered one of the mechanisms that allow hematopoietic stem cells to keep dividing in perpetuity.

The research team found that a form of the motor protein that allows muscles to contract helps these cells divide asymmetrically, so that one part remains a stem cell while the other becomes a daughter cell. Their findings could provide new insight into blood cancers, such as leukemia, and eventually lead to ways of growing transfusable blood cells in a lab.

Researchers develop new method for corneal stem cell treatments

Schematic diagram of the human eye showing
the cornea as separated from the sclera
by the corneal limbus
Scientists at the Cedars-Sinai Regenerative Medicine Institute have designed and tested a novel, minute-long procedure to prepare human amniotic membrane for use as a scaffold for specialized stem cells that may be used to treat some corneal diseases. This membrane serves as a foundation that supports the growth of stem cells in order to graft them onto the cornea.

The new method may accelerate research and clinical applications for stem cell corneal transplantation.

Corneal blindness affects more than 8 million people worldwide. Among other causes, corneal blindness may be the result of corneal stem cell deficiency, a disease usually resulting from genetic defects or injury to the eye -- such as burns, infection or chronic inflammation -- that can lead to vision loss.

A feasible treatment to rectify vision loss for such patients is corneal stem cell transplantation, either as a biopsy from another eye or by transplanting cultured stem cells, although this promising approach is not yet fully standardized.

Prostate cancer stem cells found to be a "moving target"

Prostate and nearby organs
Drs. Andrew Goldstein, Owen Witte, and Tanya Stoyanova and their colleagues from UCLA's Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research recently announced that they have found that prostate cancer can develop in one type of stem cell, then evolve to be maintained by a stem cell that looks very different, making prostate cancer stem cells a "moving target" for treatments. The breakthrough discovery connects directly to the development of future therapeutics that target cancer.

Adult stem cells are tissue-specific regenerative cells that replace diseased or damaged cells in the body's organs. Drs. Goldstein, Witte and colleagues previously reported in Science that prostate cancer can start in basal type stem cells. Building on that discovery, they found that tumors can start in basal stem cells that evolve to luminal-like cells. This means that the source of the disease they wish to target with therapy -- the tumor stem cell -- can change over time.

Tuesday, 26 November 2013

New stem cell platform technology recognized with patent award

Stem cell therapeutics provider Parcell Laboratories announced today that the U.S. Patent and Trademark Office (PTO) has issued their company the Patent No. 8,574,567 entitled "Multipotent Stem Cells and Uses There of" on November 5.

The newly issued patent concerns the Early Lineage Adult (ELA®) stem cell, and relates to providing an isolated population of stem cells that exist in the synovial fluid, blood, and other tissues in the body, and related therapeutic methods. Parcell Laboratories holds the exclusive worldwide license to the ELA stem cell platform technology, which was originally discovered by scientists affiliated with the Brigham and Women's Hospital and Harvard Medical School. This multipotent stem cell patent has a term extending through 2028.

UCLA researchers discover placenta progenitor cell that may illuminate pregnancy complications

Dr. Hanna Mikkola
Dr. Hanna Mikkola and researchers at the UCLA's Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research announced today that they have identified a novel progenitor cell and a related cell communication pathway that are key to the successful growth of a healthy placenta.

Led by Dr. Mikkola, associate professor of molecular, cell, and developmental biology in the life sciences, and Dr. Masaya Ueno, post-doctoral fellow, the team's discovery gives scientists a "tool box" for understanding the developmental hierarchy of progenitor cells, cells that develop into other cells, that initiate growth of the placenta, and greatly increases the knowledge of what might cause pregnancy complications.

Monday, 25 November 2013

Human neural stem cells could be help in the treatment of critical limb ischemia

Vascular ischaemia of the toes
with characteristic cyanosis.
According to a new study by researchers at the University of Bristol's School of Clinical Sciences, human neural stem cells could improve blood flow in critical limb ischemia through the growth of new vessels. Critical limb ischemia (CLI) is a disease that severely obstructs arteries and reduces the blood flow to legs and feet. CLI remains an unmet clinical problem and with an ageing population and the rise in type II diabetes, the incidence of CLI is expected to increase.

Current stem cell therapy trials for the treatment of CLI have revitalised new hope for improving symptoms and prolonging life expectancy. However, there are limitations on the use of autologous cell therapy. The patient's own stem cells are generally invasively harvested from bone marrow or require purification from peripheral blood after cytokine stimulation. Other sources contain so few stem cells that ex vivo expansion through lengthy bespoke Good Manufacturing Practice processes is required. Ultimately, these approaches lead to cells of variable quality and potency that are affected by the patient's age and disease status and lead to inconsistent therapeutic outcomes.

Sunday, 24 November 2013

Notch signaling pathway keeps immature T-Cells on the right track

Scanning electron micrograph of a human T cell
The lab of Avinash Bhandoola, PhD, professor of Pathology and Laboratory Medicine at Penn Medicine, has been studying the origins of T cells for a long time now. One protein called Notch, which has well-known roles in the development of multiple tissues, plays an essential role in triggering T-cell development. T cells are immune cells that are made in the thymus, a small organ situated under the breastbone near the heart.

However, T cells, like all blood-cell types, originate from hematopoietic stem cells in the bone marrow. Immature T-cell progenitors leave the bone marrow, settle within the thymus, and eventually give rise to T cells.

With graduate student Maria Elena De Obaldia, Bhandoola describes in a new study published in Nature Immunology this month how Notch signaling induces expression of genes that promote the maturation of T cells and discourage alternative cell fates. Deficiency of the Notch target gene Hes1 in blood stem cells results in extremely low T-cell numbers, but the underlying mechanism is unknown. Keeping in mind that Notch signaling gone awry induces leukemia.

Saturday, 23 November 2013

Spanish researchers grow artificial skin using umbilical cord stem cells

The members of the Tissue Engineering Team
at the Dept. of Histology at the University of Granada.
Yesterday, researchers at the University of Granada announced an important scientific breakthrough, that may aid in the immediate use of artificially-grown skin for major burn patients, since the skin could be stored in tissue banks and made available when needed.

One of the problems major burn victims face is that, using the current protocols for artificial skin, they need to wait several weeks in order for it to be grown, using healthy skin from the patient himself.

The Spanish scientists, from the Tissue Engineering Research Group, from the Dept. of Histology at the University of Granada, say they have managed - for the first time - to grow artificial skin from stem cells derived from the umbilical cord. Their study, published in the journal Stem Cells Translational Medicine, shows the ability of Wharton jelly mesenschymal stem cells to turn to oral-mucosa or skin-regeneration epithelia.

Friday, 22 November 2013

Newly found brown fat stem cells may be the key for treating Diabetes and Obesity

Brown adipose tissue (fat) in a woman
shown in a PET/CT exam
Obesity and diabetes have become a global epidemic leading to severe cardiovascular disease. Now, researchers at the University of Utah say that their recent identification of brown fat stem cells in adult humans may lead to new treatments for heart and endocrine disorders.

The study was led by Amit N. Patel, M.D. M.S., director of Clinical Regenerative Medicine and Tissue Engineering and associate professor in the Division of Cardiothoracic Surgery at the University of Utah School of Medicine.

Prior to Patel's study, it was thought that brown fat stem cells did not exist in adults. Children have large amounts of brown fat that is highly metabolically active, which allows them to eat large amounts of food and not gain weight.

Patel notes, adults generally have an abundance of white fat in their bodies, which leads to weight gain and cardiovascular disease but this is not seen in brown fat. As people age, the amount of white fat increases while brown fat decreases which in turn contributes to diabetes and high cholesterol.

Alexander Disease reveals clues about broader brain pathology

Brain of a 4-year-old boy with Alexander disease
showing macroencephaly and periventricular demyelinisation
Alexander disease (also known as fibrinoid leukodystroph) is a devastating brain disease that very few have actually heard of.

Alexander disease strikes young or old, and in children destroys white matter in the front of the brain. Many patients, especially those with early onset, have significant intellectual disabilities.

Regardless of the age when it begins, Alexander disease is always fatal. It typically results from mutations in a gene known as GFAP (glial fibrillary acidic protein), leading to the formation of fibrous clumps of protein inside brain cells called astrocytes.

Thursday, 21 November 2013

Researchers develop functional cardiac microtissues using human stem cells

A new study published in top biomedical journal PNAS (Proceedings of the National Academy of Science) this week by scientists at the University of Toronto’s Institute of Biomaterials & Biomedical Engineering (IBBME) and the McEwen Centre for Regenerative Medicine has identified the optimal structure and cell ratio associated with proper heart function. Furthermore, the discovery has already led the team to another research first: the engineering of the first-ever living, three-dimensional human arrhythmic tissue.

The study marks the first time that researchers have tried to define and formulate the precise type and ratio of cell types that produce highly functional cardiac tissue.

Wednesday, 20 November 2013

Clinical studies show stem cells are effective in cardiac therapy

Building on a trailblazing body of work in stem cell research at the University of Miami Miller School of Medicine, an interdisciplinary team led by Joshua M. Hare, M.D., Director of the Interdisciplinary Stem Cell Institute, revealed the results of two pioneering studies in cardiac stem cell therapy during oral presentations at the American Heart Association national convention held in Dallas, today and Monday.

Both studies build on Hare’s scientific and clinical research in the field of cardiac stem cell therapy. "The results of these studies  show that mesenchymal stem cells can have a major impact on cardiac care." said Hare, Chief Science Officer at the Miller School.

The first study, Transendocardial Autologous Cells in Ischemic Heart Failure (TAC-HFT), is being presented in the late-breaking sessions as it is simultaneously being published in the Journal of the American Medical Association(JAMA).

Bone marrow mononuclear stem cells show no signs in improving heart function says TIME study

New data reported by the Cardiovascular Cell Therapy Research Network (CCTRN) at the 2013 Scientific Sessions of the American Heart Association in Dallas showed that the use of bone marrow mononuclear stem cells (BMCs) did not improve heart function significantly more at one year than at six months.

While there was measurable decrease in the size of scar tissue at six and 12 months, stem cells administered as a part of the TIME (Transplantation In Myocardial Infarction Evaluation) study did not improve overall heart functionality. The results were presented by Jay Traverse, MD of the Minneapolis Heart Institute Foundation on Nov. 18, 2013.

Monday, 18 November 2013

New Midwest Stem Cell Therapy Center to host stem cell conference

The Midwest Stem Cell Therapy Center at the University of Kansas Medical Center recently announced that it will host its inaugural in-depth educational conference about adult stem cell treatments next Saturday, Nov. 23 in Kansas City.

Purpose of the conference (which provides continuing Education credits) is to update health professionals and trainees about advances in therapy with adult stem cells, as well as explaining adult stem cell biology and its potential for tissue and organ regeneration.

Please visit http://www.continuinged.ku.edu/kumc/cell-therapy/ for reservations and more info.

Salk researchers generate "mini-kidney" structures from human pluripotent stem cells

Salk researchers Ilir Dubova, Ignacio Sancho Martinez,
Yun Xia, Juan Carlos Izpisua Belmonte and Emmanuel Nivet
Diseases affecting the kidneys represent a major and unsolved health issue all over the world. The kidneys rarely recover their function, once they are damaged by disease, highlighting the urgent need for better knowledge of kidney development and physiology.

Yesterday, a research team led by scientists at the Salk Institute for Biological Studies announced that it has developed a novel platform to study kidney diseases, opening new avenues for the future application of regenerative medicine strategies to help restore kidney function.

The Salk researchers said that they have generated -for the first time - 3D kidney structures from human stem cells, opening new avenues for studying the development and diseases of the kidneys and to the discovery of new drugs that target human kidney cells.

Wednesday, 13 November 2013

Human iPSCs used to reveal mechanisms of Beta-Cell Failure in Wolfram syndrome

Researchers at the New York Stem Cell Foundation (NYSCF) Research Institute and Columbia University Medical Center (CUMC) have used induced pluripotent stem cells created from the skin of patients with a rare form of diabetes (Wolfram syndrome) to elucidate an important biochemical pathway for beta-cell failure in diabetes.

During the study, the NYSCF team first produced induced pluripotent stem (iPCs) cells from skin samples from individuals with Wolfram syndrome. They then derived insulin-producing cells (beta cells) from these iPCs cells, creating a human diabetes model in vitro. Next, they showed that the beta cells failed to normally secrete insulin because of protein-folding -- or endoplasmic reticulum (ER) -- stress. They found that a chemical, 4-phenyl butyric acid, that relieves this stress, prevents the cells from failing, suggesting a potential target for clinical intervention.

UCLA doctors test stem-cell therapy to improve blood flow in angina patients

Marty Greenfield with UCLA doctors
Marty Greenfield lives with crushing pain every day due to angina, a condition that is caused by an inadequate supply of blood to the heart.

He has suffered a heart attack, and a coronary bypass procedure and angioplasty have provided little relief. His doctor referred him to UCLA to be considered for a heart transplant.

Dr. Jonathan Tobis, a UCLA clinical professor of cardiology, performed an angiogram and angioplasty on Greenfield, 64, but found that he was not a candidate for a heart transplant because his heart muscle function was still good.

Advanced Melanoma patients long-term survival improved with California Stem Cell, cell therapy

A skin Melanoma
Advanced melanoma patients who received an experimental patient-specific tumor stem cell therapy as part of several clinical trials experienced superior survival rates compared to patients who did not receive the therapy, according to a presentation by Robert Dillman, MD, during the Society for Immunotherapy of Cancer (SITC) annual meeting in National Harbor, Maryland.

Dr. Dillman’s presentation, entitled High-dose IL-2 in Metastatic Melanoma: Better Survival in Patients Who Also Received Patient-Specific Autologous Tumor Cell Vaccine, highlighted results from retrospective analysis of Phase II clinical trials conducted at Hoag Hospital Presbyterian in Newport Beach, CA, where Dr. Dillman serves as Executive Medical Director of the Hoag Institute for Research and Education.

Monday, 11 November 2013

Researchers identify signal that enhance survival of new brain cells

Illustration of parvalbumin-expressing
interneurons delivering lifesaving
chemical messengers  to newborn neurons
via tentacle-like synapses.
A specialized type of brain cell that tamps down stem cell activity ironically, perhaps, encourages the survival of the stem cells' progeny, Johns Hopkins researchers report.

Understanding how these new brain cells "decide" whether to live or die and how to behave is of special interest because changes in their activity are linked to neurodegenerative diseases such as Alzheimer's, mental illness and aging.
"We've identified a critical mechanism for keeping newborn neurons, or new brain cells, alive. Not only can this help us understand the underlying causes of some diseases, it may also be a step toward overcoming barriers to therapeutic cell transplantation.", said Hongjun Song, Ph.D., professor of neurology and director of Johns Hopkins Medicine's Institute for Cell Engineering's Stem Cell Program.

Study reveals how jaw stem cells form benign Tumors

A recent study by researchers at the Ostrow School of Dentistry of USC shows how changes in cell signaling can cause ordinary stem cells in the jaw to start forming benign but potentially harmful tumors.

Principal investigator Songtao Shi, professor at the Ostrow School's Center for Craniofacial Molecular Biology, said that ossifying fibromas, the type of tumors they focused on in this study, are benign but can grow aggressively and cause progressive enlargement of the jaw.

Saturday, 9 November 2013

Researchers identify new trigger for Breast Cancer Metastasis

Breast cells with reduced mtDNA (right) became
structurally disorganized compared to unmodified cells (left)
For a long time now, researchers have observed that tumor cells from certain breast cancer patients with aggressive forms of the disease contained low levels of mitochondrial DNA. But, until now, no one was able to explain how this characteristic influenced disease progression.

Today, researchers at the University of Pennsylvania have revealed how a reduction in mitochondrial DNA content leads human breast cancer cells to take on aggressive, metastatic properties. Their work, published in the journal Oncogene, breaks new ground in understanding why some cancers progress and spread faster than others and may offer clinicians a biomarker that would distinguish patients with particularly aggressive forms of disease, helping personalize treatment approaches.

Thursday, 7 November 2013

Researchers regrow hair, cartilage, bone and other soft tissues in a mouse model

George Daley
Young animals are known to repair their tissues with little effort, but can this capacity be recaptured in adult individuals? A new study by researchers at the Stem Cell Program at Boston Children's Hospital suggests that it can.

By reactivating a dormant gene called Lin28a, which is active in embryonic stem cells, researchers were able to regrow hair and repair cartilage, bone, skin and other soft tissues in a mouse model.

The study also found that Lin28a promotes tissue repair in part by enhancing metabolism in mitochondria -- the energy-producing engines in cells -- suggesting that a mundane cellular "housekeeping" function could open new avenues for developing regenerative treatments.
"Efforts to improve wound healing and tissue repair have mostly failed, but altering metabolism provides a new strategy which we hope will prove successful." said the study's senior investigator George Q. Daley, MD, PhD, director of Boston Children's Stem Cell Transplantation Program and an investigator with the Howard Hughes Medical Institute.

Researchers develop muscle tissue in diseased mice and grow human muscle cells in a dish

Leonard Zon
Skeletal muscle tissue has proved to be quite difficult to grow in patients with muscular dystrophy and other disorders that degrade and weaken muscle.

Today, researchers at Boston Children's Hospital's Stem Cell Program reported that boosting muscle mass and reversing disease in a mouse model of Duchenne muscular dystrophy, using a "cocktail" of three compounds identified through a new rapid culture system.

Adding the same compounds to induced pluripotent stem cells derived from patients' skin cells, they then successfully grew human muscle cells in a dish.

Senior investigator Leonard Zon, MD, director of the Stem Cell Program at Boston Children's and an investigator with the Howard Hughes Medical Institute, hopes for clinical trials to begin transplanting these cells into patients with muscle loss in the next several years.

 In the meantime, the screening technique, described in the journal Cell (published online November 7), can also be applied to multiple disorders beyond muscular dystrophy, he said.

ISCO to present data from its Parkinson's stem cell program at Society for Neuroscience Annual Meeting

International Stem Cell Corporation (ISCO),  a California-based biotechnology company developing stem cell based therapies, announced today that its Chief Scientific Officer Dr. Ruslan Semechkin will be presenting data from ISCO's stem cell research on Parkinson's disease at the Society for Neuroscience annual meeting in San Diego, CA on November 10, 2013.

New report calls for sustained public endorsement and funding for human stem cell research

A strategic report from the European Science Foundation examines the key scientific questions for human stem cell research in the context of the rapidly emerging field of regenerative medicine. In parallel to the potential new treatments for incurable diseases resulting from stem cell research, heated ethical and legal debates have arisen across the world.

This report presents a comparative view of the legislative framework on human stem cell research across Europe and provides a selection of success stories in frontier research and clinical trials that underpin the advances achieved in Europe to date.

Stem cells offer hope for Hurler's syndrome

University of Adelaide research using special adult stem cells is promising new hope for better treatments for the devastating genetic disease Hurler's syndrome.

Hurler's syndrome (also known as mucopolysaccharidosis type I (MPS I)  and  gargoylism) has a frequency of one in 100,000 live births in Australia and sufferers develop severe mental and physical disabilities and often die in their early teens. The disease is caused by a single defective enzyme that is essential for breaking down complex sugars in cells.

Wednesday, 6 November 2013

Bioheart announces with Global Stem Cells Group to provide Bioheart therapies and training

Bioheart Inc., a biotech company focused on the discovery, development and commercialization of autologous cell therapies to treat cardiovascular disease, announced yesterday it has reached an agreement with Global Stem Cells Group of Miami to provide Bioheart therapies and products to its worldwide network of physicians and qualified patients.

The agreement between the two companies also provides an opportunity for Global Stem Cells Group to expand the network by training additional physicians in Bioheart's regenerative medicine techniques while contributing to the development and commercialization of Bioheart's regenerative medicine products.

Monday, 4 November 2013

Stem cell treatment shown to improve cognitive abilities after brain injury

Charles Cox
New data from a preclinical study led by Charles Cox, M.D., from The University of Texas Health Science Center at Houston (UTHealth) Medical School reveals that a stem cell therapy previously known to reduce inflammation in the critical time window after traumatic brain injury, also promotes lasting cognitive improvement.

Cellular damage in the brain after traumatic injury can cause severe, ongoing neurological impairment and inflammation.

As of now, few treatment options are available for this problem. About half of patients with severe head injuries need surgery to remove or repair ruptured blood vessels or bruised brain tissue.

Nanotechnology can advance Regenerative Medicine

A new study by Taiwanese researchers reveals how nanotechnology may be used to provide new strategies for regenerative medicine, including better tools to improve or restore damaged tissues. Published in the journal Science and Technology of Advanced Materials, the study summarizes the current state of knowledge on nanotechnology* with application to stem cell biology.

Stem cells are considered an important potential source for repairing damaged human tissues. Researchers have found that the adhesion, growth, and differentiation of stem cells are likely controlled by their surrounding microenvironment, which contains both chemical and physical cues.

These cues include the “nanotopography” of the complex extracellular matrix or architecture that forms a network for human tissues.

Saturday, 2 November 2013

Researchers model familial amyloidosis for the first time

Researchers from Boston University School of Medicine (BUSM) and Boston Medical Center (BMC) announced yesterday that they have developed the first known disease-specific induced pluripotent stem cell (iPSC) lines from a patient with familial transthyretin amyloidosis. They hope that their findings may lead to new treatments for genetic diseases such as familial amyloidosis.

Familial transthyretin amyloidosis (ATTR) is a lethal, autosomal dominant protein-folding disorder caused by one of more than 100 distinct mutations in the transthyretin (TTR) gene. In ATTR, protein secreted from the liver aggregates and forms fibrils in target organs, chiefly the heart and peripheral nervous system, highlighting the need for a model capable of duplicating the multisystem complexity of this clinically variable disease.

Prospects for organ regeneration without stem cells

Harvard Stem Cell Institute (HSCI) researchers have a new model for how the kidney repairs itself, a model that adds to a growing body of evidence that mature cells are far more plastic than it was previousy thought.

After injury, mature kidney cells dedifferentiate into more primordial versions of themselves, and then differentiate into the cell types needing replacement in the damaged tissue. This finding conflicts with a previously held theory that the kidney has scattered stem cell populations that respond to injury. The research appears online inPNAS Early Edition.

HSCI Kidney Diseases Program Leader Benjamin Humphreys, MD, PhD, a Harvard Medical School assistant professor at Brigham and Women's Hospital, was suspicious of the kidney stem cell repair model because his previous work suggested that all kidney cells have the capacity to divide after injury. He and his colleagues decided to test conventional wisdom by genetically tagging mature kidney cells in mice that do not express stem cell markers; the hypothesis being that the mature cells should do nothing or die after injury. 

The results showed that not only do these fully differentiated cells multiply, but they can multiply several times as they help to repair the kidney.