Category Archives: Stem Cell Videos

Study finds no evidence of stem cells in mouse ovaries

Web edition : Monday, July 9th, 2012

Women may indeed be limited to the number of eggs their ovaries contain at birth, a new study finds, directly contradicting recent research that suggests otherwise.

Scientists have long thought that female mammals, including humans, are born with all the egg cells they will ever have. But a few papers, culminating with a study published earlier this year in Nature Medicine, have suggested that ovaries contain rare stem cells that can replenish egg supplies (SN: 4/7/12, p. 8). These egg-producing stem cells could lead to new treatments for fertility problems, ways to delay menopause and advancements in the basic understanding of human egg cells.

Not so fast, says Kui Liu, a molecular reproductive biologist at the University of Gothenburg in Sweden. Working with mice, Liu and his colleagues used a technique to identify egg cells and their precursors in ovaries. The team found no evidence of the stem cells in ovaries that reproductive biologist Jonathan Tilly of Massachusetts General Hospital and colleagues recently described in Nature Medicine.

To look for egg-making stem cells in mouse ovaries, Liu and his colleagues genetically engineered mice so that every cell glows green with a fluorescent protein, except for eggs, sperm and cells destined to become gametes. Those cells glow yellow, blue or red. The scientists found cells glowing red purported gamete precursors in the ovary, but those cells did not divide the way stem cells would and did not produce new eggs, leading the researchers to conclude that stem cells dont exist in the ovary. The researchers report their work online July 9 in the Proceedings of the National Academy of Sciences.

The new finding in no way disproves the existence of egg-making stem cells in the ovary, says Evelyn Telfer, a reproductive biologist at the University of Edinburgh. For one thing, these cells are absolutely not the same as the ones Tillys got, she says. The cells Liu found are much larger and are probably already nondividing egg cells.

Liu says his point in publishing the paper is not to say that Tilly is wrong, but to urge scientists to take a hard look at the evidence for and against stem cells in the ovary.

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Egg production after birth questioned

SCHAUMBURG, Ill.--(BUSINESS WIRE)--

The Gateway for Cancer ResearchSM (www.demandcurestoday.org) announces an exciting new Gateway-funded phase II study using ADAPT therapy for treatment of metastatic colorectal cancer based on a 2010 AACR presentation by Dr. Lin and his collaborators.

The clinical trial, being led by Dr. Edward Lin, a medical oncologist at the University of Washington, Fred Hutchinson Cancer Research Center and an accomplished researcher and expert in gastrointestinal cancers, is the first to specifically target colon cancer stem cells.

The study will use a unique combination drug therapy of Capecitabine (a chemotherapy drug) and Celecoxib (an FDA approved arthritis medication) to wake up and to kill colon cancer stem cells. The treatment works by activating cancer stem cells that hibernate during chemotherapya chief cause of treatment failureso they can be destroyed. The proper sequence is necessary to consistently kill the dormant cells. The ADAPT concept was proposed by Drs. Lin and Linheng Li, a prominent stem cell biologist.

It is a very powerful drug combination with good preliminary results. Pilot studies have shown significantly increased survival rates compared with conventional therapy. Of 124 treated patients, 40% of those treated with this protocol achieved complete remission or near remission with a median survival of 93.7 months and only 1/3 of the patients had surgical removal of the metastasis. The average length of survival for stage IV colorectal cancer patients on conventional treatment is about 20-24 months and 46 months for complete responders.

A lot of patients we didnt expect to see live, are living and thriving, says Dr. Lin. It also allows a good quality of life for patients. The treatment is offering an immediate benefit to todays cancer patients. 95% of participants are out and about in their daily lives, doing what they need to do without skipping a beat.

Thomas Oberdorf, a 5-year colorectal cancer survivor who benefitted from Dr. Lins treatment protocol is grateful. As a stage IV colorectal cancer patient, I hoped to live another two years to see my daughter through to age 11. Thanks to Dr. Lins treatment protocol, I am healthy and am hoping for another 50 years, said Oberdorf who did not miss a beat as CFO of a large organization during the course of his treatment.

The drug combination allowed a good quality of life for most patients. An independent randomized phase III study also showed that celecoxib reduced capecitabine induced hand foot syndrome that was observed by Dr. Lin.

Tiffany Heigle, a stage IV colon cancer patient when she first met with Dr. Lin, credits him for 10 years of survival and precious time with her family. Because of Dr. Lins new treatment approach, I can enjoy being a mom to my 18-year-old freshman in college and my 15-year-old freshman in high school, says Heigle. I have been allowed to see them grow up due to this research.

Colorectal cancer is the number 3 killer and an estimated 1.2 million people around the globe have the disease. More than 70,000 deaths per year in the US alone are attributed to colorectal cancer and for patients with stage IV disease; five year survival is under 10% with current treatments. Surgery remains the only treatment that yielded long term survival and this may be changed by the current study.

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First Study Targeting Colorectal Cancer Stem Cells to Begin

Celena Hollis

DENVER If you want to honor slain police officer Celena Hollis, who was killed at a City Park Jazz festival last month, the Denver Police Departments District 2 is urging you to donate your bone marrow or stem cells.

Hollis was instrumental in setting up this donor drive before her death and donated her organs after her passing. She was also an advocate for minorities, serving as the president for the Denver Police Department Black Police Officers Organization

All of that considered, Hollis colleagues are hoping to continue the self-less work that came to define the fallen officer.

July is African American Bone Marrow Awareness Month and the goal is to raise awareness about the critical need for African Americans to join the national Be The Match Registry, said Dianna Hemphill, Public Relations Specialist at the Bonfils Blood Center, where the drive will be held Friday from 11 a.m. 2 p.m. (Directions can be found here.)

More than 10,000 people from all ethnic backgrounds are diagnosed with life-threatening blood diseases every year. Approximately 70 percent of these patients do not have a compatible donor in their family or are unable to use their own cells. At that point, they need to search the Be The Match Registry for an unrelated donor.

Only 25 percent of that registry is ethnically diverse.

Thats why the need for more diverse donors is critical, Bonfils Vice President of Marketing Jessica Maitland said.

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Donate marrow, stem cells Friday to honor fallen police officer

The Canadian Press - ONLINE EDITION

By: Sheryl Ubelacker, The Canadian Press

5/07/2012 3:37 PM | Comments: 0

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Principal investigator Dr.Freda Miller is shown in an undated handout photo.Canadian researchers have found that a drug widely used to treat Type 2 diabetes can help trigger the mechanism that signals stem cells to become brain cells.THE CANADIAN PRESS/HO - Hospital for Sick Children

TORONTO - A drug commonly used to control Type 2 diabetes can help trigger stem cells to produce new brain cells, providing hope of a potential means to treat brain injuries and even neurodegenerative diseases like Alzheimer's, researchers say.

A study by scientists at Toronto's Hospital for Sick Children found the drug metformin helps activate the mechanism that signals stem cells to generate neurons and other brain cells.

"If you could take stem cells that normally reside in our brains and somehow use drugs to recruit them into becoming appropriate neural cell types, then you may be able to promote repair and recovery in at least some of the many brain disorders and injuries for which we currently have no treatment," said principal investigator Freda Miller.

"This work is happening against a background of a lot of excitement in the stem cell field about the idea that since we now know that we have stem cells in many of our adult tissues, then perhaps if we could figure out how to pharmacologically tweak those stem cells, then perhaps we could help to promote tissue repair," added Miller, a senior scientist at SickKids.

The research, published online Thursday in the journal Cell Stem Cell, involved lab-dish experiments using both mouse and human brain stem cells, as well as learning and memory tests performed on live mice given the drug.

Originally posted here:
Diabetes drug triggers neuron growth, potential to regenerate brain cells: study

ScienceDaily (July 5, 2012) In the July 6 issue of Cell Stem Cell, researchers at the University of California, San Diego School of Medicine describe how human epidermal progenitor cells and stem cells control transcription factors to avoid premature differentiation, preserving their ability to produce new skin cells throughout life.

The findings provide new insights into the role and importance of exosomes and their targeted gene transcripts, and may help point the way to new drugs or therapies for not just skin diseases, but other disorders in which stem and progenitor cell populations are affected.

Stem cells, of course, are specialized cells capable of endlessly replicating to become any type of cell needed, a process known as differentiation. Progenitor cells are more limited, typically differentiating into a specific type of cell and able to divide only a fixed number of times.

Throughout life, human skin self-renews. Progenitor and stem cells deep in the epidermis constantly produce new skin cells called keratinocytes that gradually rise to the surface where they will be sloughed off. One of the ways that stem and progenitor cells maintain internal health during their lives is through the exosome -- a collection of approximately 11 proteins responsible for degrading and recycling different RNA elements, such as messenger RNA that wear out or that contain errors resulting in the translation of dysfunctional proteins which could potentially be deleterious to the cell.

"In short," said George L. Sen, PhD, assistant professor of medicine and cellular and molecular medicine, "the exosome functions as a surveillance system in cells to regulate the normal turnover of RNAs as well as to destroy RNAs with errors in them."

Sen and colleagues Devendra S. Mistry, PhD, a postdoctoral research fellow, and staff scientist Yifang Chen, MD, PhD, discovered that in the epidermis the exosome functions to target and destroy mRNAs that encode for transcription factors that induce differentiation. Specifically, they found that the exosome degrades a transcription factor called GRHL3 in epidermal progenitor cells, keeping the latter undifferentiated. Upon receiving differentiation inducing signals, the progenitor cells lose expression of certain subunits of the exosome which leads to higher levels of GRHL3 protein. This increase in GRHL3 levels promotes the differentiation of the progenitor cells.

"Without a functioning exosome in progenitor cells," said Sen, "the progenitor cells prematurely differentiate due to increased levels of GRHL3 resulting in loss of epidermal tissue over time."

Sen said the findings could have particular relevance if future research determines that mutations in exosome genes are linked to skin disorders or other diseases. "Recently there was a study showing that recessive mutations in a subunit of the exosome complex can lead to pontocerebellar hypoplasia, a rare neurological disorder characterized by impaired development or atrophy of parts of the brain," said Sen. "This may potentially be due to loss of progenitor cells. Once mutations in exosome complex genes are identified in either skin diseases or other diseases like pontocerebellar hypoplasia, it may be possible to design drugs targeting these defects."

Funding for this research came, in part, from the National Institutes of Health grant K01AR057828-04 and a Ray Thomas Edwards Award.

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The key (proteins) to self-renewing skin

(PRWEB) July 05, 2012

Researchers at Adelaide University have developed a potential therapy for stroke victims utilizing dental stem cells to regenerate damaged brain cells.

The study involved the use of human dental pulp stem cells in rats suffering from post- stroke symptoms. The stem cells were transplanted into the damaged brains of the rats with the rats showing significant improvement in brain function, motor skills and cognitive abilities within several weeks. The therapy poses a new possibility for patients who have suffered a stroke. Patients will be able to use stem cells extracted from their own teeth to regenerate damaged brain tissue. The use of autologous stem cells eliminates the risk of rejection and the need for immune-suppression drugs and results in a more positive outcome. The research is so promising that the researchers hope to begin clinical trials within three to four years.

The research is another example of the inherent plasticity of dental stem cells, i.e. their ability to differentiate into a wide range of tissue types that may be utilized to treat a broad array of disease, trauma and injury. Banking your own valuable dental stem cells for use in emerging regenerative therapies is both convenient and affordable and as easy as a trip to the dentists.

To learn more about how you can bank your valuable dental stem cells , visit http://www.StemSave.com or call 877-783-6728 (877-StemSave) today.

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StemSave - Researchers Utilize Dental Stem Cells for Stroke Treatment

Public release date: 4-Jul-2012 [ | E-mail | Share ]

Contact: Daniel Stimson, NINDS nindspressteam@ninds.nih.gov 301-496-5751 NIH/National Institute of Neurological Disorders and Stroke

Researchers have taken a step toward personalized medicine for Parkinson's disease, by investigating signs of the disease in patient-derived cells and testing how the cells respond to drug treatments. The study was funded by the National Institutes of Health.

The researchers collected skin cells from patients with genetically inherited forms of Parkinson's and reprogrammed those cells into neurons. They found that neurons derived from individuals with distinct types of Parkinson's showed common signs of distress and vulnerability in particular, abnormalities in the cellular energy factories known as mitochondria. At the same time, the cells' responses to different treatments depended on the type of Parkinson's each patient had.

The results were published in Science Translational Medicine.

"These findings suggest new opportunities for clinical trials of Parkinson's disease, in which cell reprogramming technology could be used to identify the patients most likely to respond to a particular intervention," said Margaret Sutherland, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS).

A consortium of researchers conducted the study with primary funding from NINDS. The consortium is led by Ole Isacson, M.D., Ph.D., a professor of neurology at McLean Hospital and Harvard Medical School in Boston.

The NINDS consortium's first goal was to transform the patients' skin cells into induced pluripotent stem (iPS) cells, which are adult cells that have been reprogrammed to behave like embryonic stem cells. The consortium researchers then used a combination of growth conditions and growth-stimulating molecules to coax these iPS cells into becoming neurons, including the type that die in Parkinson's disease.

Parkinson's disease affects a number of brain regions, including a motor control area of the brain called the substantia nigra. There, it destroys neurons that produce the chemical dopamine. Loss of these neurons leads to involuntary shaking, slowed movements, muscle stiffness and other symptoms. Medications can help manage the symptoms, but there is no treatment to slow or stop the disease.

Most cases of Parkinson's are sporadic, meaning that the cause is unknown. However, genetics plays a strong role. There are 17 regions of the genome with common variations that affect the risk of developing Parkinson's disease. Researchers have also identified nine genes that, when mutated, can cause the disease.

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Patient-derived stem cells could improve drug research for Parkinson's

ScienceDaily (July 3, 2012) searchers from the University of Maryland School of Maryland report promising results from using adult stem cells from bone marrow in mice to help create tissue cells of other organs, such as the heart, brain and pancreas -- a scientific step they hope may lead to potential new ways to replace cells lost in diseases such as diabetes, Parkinson's or Alzheimer's.

The research in collaboration with the University of Paris Descartes is published online in the June 29, 2012 edition of Comptes Rendus Biologies, a publication of the French Academy of Sciences.

"Finding stem cells capable of restoring function to different damaged organs would be the Holy Grail of tissue engineering," says lead author David Trisler, PhD, assistant professor of neurology at the University of Maryland School of Medicine.

He adds, "This research takes us another step in that process by identifying the potential of these adult bone marrow cells, or a subset of them known as CD34+ bone marrow cells, to be 'multipotent,' meaning they could transform and function as the normal cells in several different organs."

University of Maryland researchers previously developed a special culturing system to collect a select sample of these adult stem cells in bone marrow, which normally makes red and white blood cells and immune cells. In this project, the team followed a widely recognized study model, used to prove the multipotency of embryonic stem cells, to prove that these bone marrow stem cells could make more than just blood cells. The investigators also found that the CD34+ cells had a limited lifespan and did not produce teratomas, tumors that sometimes form with the use of embryonic stem cells and adult stem cells cultivated from other methods that require some genetic manipulation.

"When taken at an early stage, we found that the CD34+ cells exhibited similar multipotent capabilities as embryonic stem cells, which have been shown to be the most flexible and versatile. Because these CD34+ cells already exist in normal bone marrow, they offer a vast source for potential cell replacement therapy, particularly because they come from a person's own body, eliminating the need to suppress the immune system, which is sometimes required when using adults stem cells derived from other sources," explains Paul Fishman, MD, PhD, professor of neurology at the University of Maryland School of Medicine.

The researchers say that proving the potential of these adult bone marrow stem cells opens new possibilities for scientific exploration, but that more research will be needed to see how this science can be translated to humans.

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Adult stem cells from bone marrow: Cell replacement/tissue repair potential in adult bone marrow stem cells in animal ...

ScienceDaily (July 3, 2012) Stem cells found in amniotic fluid can be transformed into a more versatile state similar to embryonic stem cells, according to a study published July 3 in the journal Molecular Therapy. Scientists from Imperial College London and the UCL Institute of Child Health succeeded in reprogramming amniotic fluid cells without having to introduce extra genes. The findings raise the possibility that stem cells derived from donated amniotic fluid could be stored in banks and used for therapies and in research, providing a viable alternative to the limited embryonic stem cells currently available.

Amniotic fluid surrounds and nourishes the fetus in the womb. It can be extracted through the mother's abdomen using a needle in a process called amniocentesis, which is sometimes used to test for genetic diseases. The fluid contains stem cells that come from the fetus. These cells have a more limited capacity to develop into different cell types than stem cells in the embryo.

The researchers used stem cells from amniotic fluid donated by mothers undergoing amniocentesis for other purposes during the first trimester of pregnancy. The cells were grown on a gelatinous protein mixture in the lab and reprogrammed into a more primitive state by adding a drug called valproic acid to the culture medium. An extensive set of tests found that these reprogrammed cells have characteristics very similar to embryonic stem cells, which are capable of developing into any cell type in the body -- a property known as pluripotency.

Even after growing in culture for some time, the reprogrammed cells were able to develop into functioning cells of many different types, including liver, bone and nerve cells. They also maintained their pluripotency even after being frozen and rethawed.

The results suggest that stem cells derived from amniotic fluid could be used in treatments for a wide range of diseases. Donated cells could be stored in banks and used in treatments, as well as in disease research and drug screening. A previous study estimated that cells from 150 donors would provide a match for 38% of the population.

Alternatives to embryonic stem cells are keenly sought because of ethical concerns and limited availability of donor embryos. Previous research has shown that it is possible to make adult cells become pluripotent by introducing extra genes into the cells, often using viruses. However, the efficiency of the reprogramming is very low and there is a risk of problems such as tumours caused by disrupting the DNA. The new study is the first to induce pluripotency in human cells without using foreign genetic material. The pluripotent cells derived from amniotic fluid also showed some traits associated with embryonic stem cells that have not been found in induced pluripotent stem cells from other sources.

Amniocentesis is associated with a small risk of causing a miscarriage, estimated to be about one in 100.

Dr Pascale Guillot, from the Department of Surgery and Cancer at Imperial, said: "Amniotic fluid stem cells are intermediate between embryonic stem cells and adult stem cells. They have some potential to develop into different cell types but they are not pluripotent. We've shown that they can revert to being pluripotent just by adding a chemical reagent that modifies the configuration of the DNA so that genes that are expressed in the embryo get switched back on.

"These cells have a wide range of potential applications in treatments and in research. We are particularly interested in exploring their use in genetic diseases diagnosed early in life or other diseases such as cerebral palsy."

Dr Paolo De Coppi, from the UCL Institute of Child Health, who jointly led the study with Dr Guillot, said: "This study confirms that amniotic fluid is a good source of stem cells. The advantages of generating pluripotent cells without any genetic manipulation make them more likely to be used for therapy.

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Amniotic fluid yields alternatives to embryonic stem cells

FOR IMMEDIATE RELEASE: July 3, 2012

UNIVERSITY OF MARYLAND SCHOOL OF MEDICINE INVESTIGATORS FIND CELL REPLACEMENT/ TISSUE REPAIR POTENTIAL IN ADULT BONE MARROW STEM CELLS IN ANIMAL MODEL

Scientists Looking for Potential Avenue to Grow Cells of Different Organs

Newswise Baltimore, MD July 3, 2012. Researchers from the University of Maryland School of Maryland report promising results from using adult stem cells from bone marrow in mice to help create tissue cells of other organs, such as the heart, brain and pancreas - a scientific step they hope may lead to potential new ways to replace cells lost in diseases such as diabetes, Parkinsons or Alzheimers. The research in collaboration with the University of Paris Descartes is published online in the June 29, 2012 edition of Comptes Rendus Biologies, a publication of the French Academy of Sciences.

Finding stem cells capable of restoring function to different damaged organs would be the Holy Grail of tissue engineering, says lead author David Trisler, PhD, assistant professor of neurology at the University of Maryland School of Medicine.

He adds, This research takes us another step in that process by identifying the potential of these adult bone marrow cells, or a subset of them known as CD34+ bone marrow cells, to be multipotent, meaning they could transform and function as the normal cells in several different organs.

University of Maryland researchers previously developed a special culturing system to collect a select sample of these adult stem cells in bone marrow, which normally makes red and white blood cells and immune cells. In this project, the team followed a widely recognized study model, used to prove the multipotency of embryonic stem cells, to prove that these bone marrow stem cells could make more than just blood cells. The investigators also found that the CD34+ cells had a limited lifespan and did not produce teratomas, tumors that sometimes form with the use of embryonic stem cells and adult stem cells cultivated from other methods that require some genetic manipulation.

When taken at an early stage, we found that the CD34+ cells exhibited similar multipotent capabilities as embryonic stem cells, which have been shown to be the most flexible and versatile. Because these CD34+ cells already exist in normal bone marrow, they offer a vast source for potential cell replacement therapy, particularly because they come from a persons own body, eliminating the need to suppress the immune system, which is sometimes required when using adults stem cells derived from other sources, explains Paul Fishman, MD, PhD, professor of neurology at the University of Maryland School of Medicine.

The researchers say that proving the potential of these adult bone marrow stem cells opens new possibilities for scientific exploration, but that more research will be needed to see how this science can be translated to humans.

The results of this international collaboration show the important role that University of Maryland School of Medicine researchers play in advancing scientific understanding, investigating new avenues for the development of potentially life-changing treatments, says E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine.

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Study Results: Adult Stem Cells From Bone Marrow