Showing posts with label bone marrow. Show all posts
Showing posts with label bone marrow. Show all posts

Tuesday, September 11, 2012

Stem Cell Researchers Use Gene Therapy to Restore Immune Systems in 'Bubble Boy' Disease

Source: University of California, Los Angeles (UCLA), Health Sciences
Date: September 11, 2012

Summary:

UCLA stem cell researchers have found that a gene therapy regimen can safely restore immune systems to children with so-called "Bubble Boy" disease, a life threatening condition that if left untreated can be fatal within one to two years.

In the 11-year study, researchers were able to test two therapy regimens for 10 children with ADA-deficient severe combined immunodeficiency (SCID). During the study, they refined their approach to include a light dose of chemotherapy to help remove many of the blood stem cells in the bone marrow that are not creating an enzyme called adenosine deaminase (ADA), which is critical for the production and survival of healthy white blood cells, said study senior Dr. Donald Kohn, a professor of pediatrics and of microbiology, immunology, and molecular genetics in Life Sciences and a member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA.

The refined gene therapy and chemotherapy regimen proved superior to the other method tested in the study, restoring immune function to three of the six children who received it, Kohn said. Going forward, an even further refined regimen using a different type of virus delivery system will be studied in the next phase of the study, which already has enrolled eight of the 10 patients needed.

The study appears Aug. 30 in the advance online issue of the peer-reviewed journal Blood.

Sunday, September 02, 2012

Scientists Discover 'Missing Link' Between Stem Cells and the Immune System

Source: University of California, Los Angeles (UCLA), Health Sciences
Date: September 2, 2012

Summary:

UCLA researchers have discovered a type of cell that is the "missing link" between bone marrow stem cells and all the cells of the human immune system, a finding that will lead to a greater understanding of how a healthy immune system is produced and how disease can lead to poor immune function. The studies were done using human bone marrow, which contains all the stem cells that produce blood during postnatal life.

Understanding the process of normal blood formation in human adults is a crucial step in shedding light on what goes wrong during the process that results in leukemias, or cancers of the blood. The study appears Sept. 2 in the early online edition of Nature Immunology.

Thursday, May 03, 2012

Aged Hematopoietic Stem Cells Rejuvenated to Be Functionally Younger

Source: Cincinnati Children's Hospital Medical Center
Date: May 3, 2012

Summary:

Researchers have rejuvenated aged hematopoietic stem cells to be functionally younger, offering intriguing clues into how medicine might one day fend off some ailments of old age. Scientists at Cincinnati Children’s Hospital Medical Center and the Ulm University Medicine in Germany report their findings online May 3 in the journal Cell Stem Cell. The paper brings new perspective to what has been a life science controversy – countering what used to be broad consensus that the aging of hematopoietic stem cells (HSCs) was locked in by nature and not reversible by therapeutic intervention.

The findings are early and involve laboratory manipulation of mouse cells, so it remains to be seen what direct application they may have for humans. Still, the study expands what is known about the basic molecular and cellular mechanisms of aging -- a necessary step to one day designing rational approaches to aiding a healthy aging process.

One reason the research team focused on Cdc42 is that previous studies have reported elevated activity of the protein in various tissue types of older mice -- which have a natural life span of around two years. Also, elevated expression of Cdc42 has been found in immune system white blood cells in older humans.

In the current study, researchers found elevated activity of Cdc42 in the HSCs of older mice. They also were able to induce premature aging of HSCs in mice by genetically increasing Cdc42 activity in the cells. The aged cells lost structural organization and polarity, resulting in improper placement and spacing of components inside the cells. This disorganization contributed to the cells' decreased functional efficiency.

Wednesday, January 25, 2012

Environment That Nurtures Blood-Forming Stem Cells' Growth Identified

Source: UT Southwestern Medical Center
Date: January 25, 2012

Summary:

Scientists with the new Children's Research Institute at UT Southwestern Medical Center have identified the environment in which blood-forming stem cells survive and thrive within the body, an important step toward increasing the safety and effectiveness of bone-marrow transplantation. Institute investigators asked which cells are responsible for the microenvironment that nurtures haematopoietic stem cells, which produce billions of new blood cells every day. The answer: endothelial and perivascular cells, which line blood vessels. The study is available Jan. 26 in Nature.

Sunday, May 22, 2011

Study of stem cell diseases advanced by new Stanford technique

Source: Stanford University Medical Center
Date: May 22, 2011

Summary:

STANFORD, Calif. — A rare genetic disease called dyskeratosis congenita, caused by the rapid shortening of telomeres (protective caps on the ends of chromosomes), can be mimicked through the study of undifferentiated induced pluripotent stem cells, according to new findings from the Stanford University School of Medicine. Although dyskeratosis affects only about one in a million people, the scientists' findings could greatly facilitate research into this and other diseases caused by stem cell malfunctions, including some bone marrow failure syndromes and, perhaps, pulmonary fibrosis.

The study, which used iPS cells created from the cells of patients with dyskeratosis, explains why sufferers experience a wide variety in the types and severity of symptoms, ranging from abnormal skin pigmentation and nail growth to lung scarring, bone marrow failure and cancer. The key lies in the activity of telomerase, an enzyme critical to aging and cell renewal. The study will be published online May 22 in Nature.

Tuesday, March 22, 2011

Stem cells in heart form scar after heart attack

Source: Baylor College of Medicine
Date: March 22, 2011

Summary:

HOUSTON -- A fibroblast is not always just a fibroblast – particularly in the heart. In a heart attack, fibroblasts – special repair cells that form a scar after injury – come from a population of stem cells that reside within the heart, said researchers from Baylor College of Medicine and the Methodist Hospital in a report that appears in the journal Cardiovascular Research. By contrast, earlier work showed that the fibroblasts responsible for fibrosis – excess fibrous connective tissue – found in cardiomyopathy or heart failure came from a special kind of white blood cell called a monocyte, which originates in the bone marrow. The finding has implications for the treatment of heart failure, said Dr. Mark Entman, chief of the division of cardiovascular sciences in the department of medicine at BCM and the paper's corresponding author.

Monday, March 21, 2011

Stem Cells May Show Promise for People with Rapidly Progressing MS

Source: American Academy of Neurology
Date: March 21, 2011

Summary:

ST. PAUL, Minn. – A long term study reports about the effectiveness of replacing bone marrow, purposely destroyed by chemotherapy, with autologous (self) stem cell rescue for people with aggressive forms of multiple sclerosis (MS). The study is published in the March 22, 2011, print issue of Neurology®, the medical journal of the American Academy of Neurology. For the treatment, chemotherapy drugs are used to kill all of the patient's blood cells, including the immune cells that are believed to be attacking the body's own central nervous system. Bone marrow stem cells removed from the patient are purified and transplanted back into the body, which saves life by replacing the blood cells and also is proposed to 'reboot' the immune system.

HealthDay News and WebMD published news stories based on this news release today.

Monday, August 02, 2010

Purified blood stem cells improve success of bone marrow transplants in mice, study shows

Source: Stanford University School of Medicine
Date: August 2, 2010

Summary:

Researchers at the Stanford University School of Medicine have challenged decades of accepted wisdom about bone marrow transplantation with a new study showing that mice receiving purified blood stem cells are less prone to complications than mice receiving stem cells plus purified T cells. The study, led by Judith Shizuru, MD, PhD, associate professor of medicine, will be published online Aug. 2 in the Proceedings of the National Academy of Sciences.

Thursday, July 01, 2010

Patients With Treatment-Resistant Chronic Leukemia Respond Positively to Stem Cell Transplants

Source: American Society of Hematology.
Date: July 1, 2010

Summary:

(WASHINGTON) – Allogeneic (donor-derived) stem cell transplant (alloSCT) may be a promising option for patients with treatment-resistant chronic lymphocytic leukemia (CLL), regardless of the patient’s underlying genetic abnormalities, according to the results of a study published online today in Blood, the journal of the American Society of Hematology.

In alloSCT, blood stem cells are collected from a donor and then infused into the patient where they travel to the bone marrow and begin to produce new blood cells, replacing those that have been affected as a result of the disease. This type of treatment can pose serious complications, some of which are potentially fatal. In this prospective phase II study, a total of 90 patients with treatment-resistant CLL received alloSCT, and stem cell donors were either healthy siblings or unrelated, but matched, volunteers.

Prior to the transplant, patients in this study received conditioning, a standard therapy administered immediately before a stem cell transplant to help prepare the body to receive and accept the transplanted cells. The research team used a reduced-intensity conditioning approach with two common chemotherapies (fludarabine and cyclophosphamide) to reduce complications and allow the donor stem cells to fight the disease themselves.

After treatment with alloSCT, more than 40 percent of participants with this otherwise fatal disease enjoyed long-term freedom from relapse. These findings suggest that alloSCT is a feasible and potentially curative treatment for patients with high-risk CLL and should be considered for this patient population.

Sunday, March 07, 2010

Scientists identify reservoirs where HIV-infected cells can lie in wait

Source: University of Michigan Health System
Date: March 7, 2010

Summary:

ANN ARBOR, Mich. – University of Michigan scientists have identified a new reservoir for hidden HIV-infected cells that can serve as a factory for new infections. New research shows that bone marrow, previously thought to be resistant to the virus, can contain latent forms of the infection. The findings, which appear online today in Nature Medicine, indicate a new target for curing the disease so those infected with the virus may someday no longer rely on AIDS drugs for a lifetime and may open the door to new treatments. The new research also gives a broader view of how HIV overwhelms the body’s immune system and devastates its ability to regenerate itself.

Thursday, March 04, 2010

Breakthrough reveals blood vessel cells are key to growing unlimited amounts of adult stem cells

Source: Weill Cornell Medical College
Date: March 4, 2010

Summary:

In a leap toward making stem cell therapy widely available, researchers at the Ansary Stem Cell Institute at Weill Cornell Medical College have discovered that endothelial cells, the most basic building blocks of the vascular system, produce growth factors that can grow copious amounts of adult stem cells and their progeny over the course of weeks. Until now, adult stem cell cultures would die within four or five days despite best efforts to grow them.

This new finding sets forth the innovative concept that blood vessels are not just passive conduits for delivery of oxygen and nutrients, but are also programmed to maintain and proliferate stem cells and their mature forms in adult organs. Using a novel approach to harness the potential of endothelial cells by "co-culturing" them with stem cells, the researchers discovered the means to manufacture an unlimited supply of blood-related stem cells that may eventually ensure that anyone who needs a bone marrow transplant can get one.

The vascular-cell model established in this study could also be used to grow abundant functional stem cells from other organs such as the brain, heart, skin and lungs. An article detailing these findings appears in the March 5 issue of the journal Cell Stem Cell.

Wednesday, July 01, 2009

Blood stem cell growth factor reverses memory decline in mice

Source: University of South Florida Health
Date: July 1, 2009

Summary:

A human growth factor that stimulates blood stem cells to proliferate in the bone marrow reverses memory impairment in mice genetically altered to develop Alzheimer's disease, researchers at the University of South Florida and James A. Haley Hospital found. The granulocyte-colony stimulating factor (GCSF) significantly reduced levels of the brain-clogging protein beta amyloid deposited in excess in the brains of the Alzheimer's mice, increased the production of new neurons and promoted nerve cell connections. The findings are reported online in Neuroscience and are scheduled to appear in the journal's print edition in August.

Wednesday, May 13, 2009

Embryo's heartbeat drives blood stem cell formation

Source: Children's Hospital Boston
Date: May 13, 2009

Summary:

Biologists have long wondered why the embryonic heart begins beating so early, before the tissues actually need to be infused with blood. Two groups of researchers from Children's Hospital Boston, Brigham and Women's Hospital, and the Harvard Stem Cell Institute (HSCI) -- presenting multiple lines of evidence from zebrafish, mice and mouse embryonic stem cells -- provide an intriguing answer: A beating heart and blood flow are necessary for development of the blood system, which relies on mechanical stresses to cue its formation.

Their studies, published online by the journals Cell and Nature, respectively, on May 13, together offer clues that may help in treating blood diseases such as leukemia, immune deficiency and sickle cell anemia, suggesting new ways scientists can make the types of blood cells a patient needs. This would help patients who require marrow or cord blood transplants, who do not have a perfect donor match.

Thursday, April 16, 2009

Researchers succeed in multiplying blood cells in the lab

Source: University of Montreal
Date: April 16, 2009

Summary:

A team from the Institute for Research in Immunology and Cancer (IRIC) at Université de Montréal has succeeded in producing a large quantity of laboratory stem cells from a small number of blood stem cells obtained from bone marrow. The multidisciplinary team, directed by Dr. Guy Sauvageau, thus took a giant step towards the development of a revolutionary treatment based on these stem cells. This worldwide first will advance stem cell research and could have major implications in several fields for which no treatment currently exists.

Wednesday, December 10, 2008

First functional stem-cell niche model created

Source: Stanford University
Date: December 10, 2008

Summary:

Like it or not, your living room probably says a lot about you. Given a few uninterrupted moments to poke around, a stranger could probably get a pretty good idea of your likes and dislikes, and maybe even your future plans. Scientists at the Stanford University School of Medicine employing a similar "peeping Tom" tactic to learn more about how stem cells develop have taken a significant step forward by devising a way to recreate the cells' lair — a microenvironment called a niche — in an adult animal. The research marks the first time that scientists have successfully recreated a functional stem-cell niche for further study.

Wednesday, December 03, 2008

New 'control knobs' for stem cells identified

Source: Tufts University
Date: December 3, 2008

Summary:

Natural changes in voltage that occur across the membrane of adult human stem cells are a powerful controlling factor in the process by which these stem cells differentiate, according to research published by Tufts University scientists in the November 17, 2008, issue of PLoS ONE. The Tufts researchers studied the changes in membrane potential (voltage across the membrane) shown by human mesenchymal stem cells (hMSCs) obtained from donor bone marrow as the hMSCs were differentiating into fat and bone cells. They found that hyperpolarization (increased difference between the voltage in the interior and exterior of a cell) was characteristic of differentiated cells compared with undifferentiated cells and that hMSCs show different membrane potential profiles during bone vs. fat differentiation.

Thursday, November 20, 2008

Sweet success for new stem cell ID trick

Source: University of Manchester
Date: 20 November 2008

Summary:

Biomaterial scientists at the University of Manchester believe they have found a new way of isolating the ‘ingredients’ needed for potential stem cell treatments for nerve damage and heart disease. And the technique could also be used in the future to improve the efficiency of bone marrow transplants. Writing in the journal Stem Cells, the Manchester scientists report how the technique allows cells to be clearly identified depending on whether the antibodies bind themselves to the cells or not.

Monday, September 15, 2008

Embryonic stem cells might help reduce transplantation rejection

Source: University of Iowa
Date: September 15, 2008

Summary:

Researchers have shown that immune-defense cells influenced by embryonic stem cell-derived cells can help prevent the rejection of hearts transplanted into mice, all without the use of immunosuppressive drugs. The University of Iowa and the Iowa City Veterans Affairs (VA) Medical Center finding has implications for possible improvements in organ and bone marrow transplantation for humans. The study results appeared Friday in the online journal PLoS ONE.

Thursday, July 10, 2008

Cancer drug shows promise against graft vs. host disease

Source: University of Michigan
Date: July 10, 2008

Summary:

A new University of Michigan study in mice suggests that a drug recently approved to fight cancer tumors is also able to reduce the effects of graft-versus-host disease, a common and sometimes fatal complication for people who have had bone marrow transplants. Plans are under way at U-M for an initial trial of the drug in people as a new way to prevent graft-versus-host disease. Researchers expect to begin a trial within a year.

The U-M scientists tested the effects of the drug SAHA, as well as another member of a group of drugs known as HDAC inhibitors, on key immune system cells called dendritic cells. In mice, both drugs were able to significantly diminish the destructive inflammatory effects that these cells cause in graft-versus-host disease. Graft-versus-host disease occurs when immune cells in the transplanted bone marrow mount a misguided attack on body tissues. If HDAC inhibitors turn out to be safe and effective in people, they might offer a treatment option preferable to the immunosuppressant drugs used now to treat the disease. These leave people vulnerable to infection and have other significant side effects.

Thursday, June 05, 2008

New technology enhances therapeutic potential of cord blood stem cells

Source: Rush University Medical Center
Date: June 5, 2008

Summary:

A CD26 Inhibitor increases the efficiency and responsiveness of umbilical cord blood for bone marrow transplants and may improve care for blood cancer patients according to research from Rush University Medical Center being presented at the 6th Annual International Umbilical Cord Blood Transplantation Symposium, June 6-7 in Los Angeles. Kent W. Christopherson II, PhD, assistant professor of medicine and researcher in the Sections of Hematology and Stem Cell Transplantation at Rush, is researching a CD26 Inhibitor, a small molecule enzyme inhibitor that enhances directional homing of stem cells to the bone marrow by increasing the responsiveness of donor stem cells to a natural homing signal. Homing is the process by which the donor stem cells find their way to the bone marrow. It is the first and essential step in stem cell transplantation.