“Latest Stem Cells News”

Researchers and using stem cells as tools for disease study, drug screening, clinical trial strategy, and personalized medicine. The induced Pluripotent Stem cell (iPS) is giving us a chance to rethink the way we are developing new drugs. These iPS cells are usually created from somatic cells (such as skin), and not embryos or adult stem cells. In creating iPS from patients’ diseased cells, scientists can study the disease in vitro, looking for disease phenotypes, applying microenvironmental stress, and testing new drugs. Compared to animal model testing (e.g. mice), this represents a significant breakthrough, that can be used to validate clinical development strategy and test efficacy in specific groups of patients. iPS is bringing a revolution in drug discovery methodology which is being used to bridge genetics, cell biology, and physiology.

from http://biobusiness.tv/videos/208

Incoming search terms:

Never mind facial masks and exfoliating scrubs, skin takes care of itself. Stem cells located within the skin actively generate differentiating cells that can ultimately form either the body surface or the hairs that emanate from it. In addition, these stem cells are able to replenish themselves, continually rejuvenating skin and hair. Now, researchers at Rockefeller University have identified two proteins that enable these skin stem cells to undertake this continuous process of self-renewal.

The work, published in Nature Genetics, brings new details to the understanding of how stem cells maintain — and lose — their status as stem cells and are able to specialize into various types of cells. It also further dissects a ubiquitous Rube Goldberg-like pathway whose molecular gears and levers play an important role in activating stem cells to divide and transform into tissue-making cells.

Lead researcher Elaine Fuchs, head of the Laboratory of Mammalian Cell Biology and Development, and first author Hoang Nguyen, a former postdoc in the lab, worked with mice engineered to lack the proteins TCF3 and TCF4, which reside in the nucleus of skin stem cells, where they bind to DNA to turn genes off that would otherwise cause the stem cells to differentiate. They found that without TCF3 and TCF4, all of the layers of the mice’s skin still develop properly, but they cannot be maintained.

“The epidermal stem cells — one of the types of stem cells in the skin — lose their capacity to self-renew and replace skin cells that have died,” says Nguyen, who is now an assistant (…)

from http://www.sciencedaily.com/releases/2009/09/090927152828.htm

Incoming search terms:

Globs of human fat removed during liposuction conceal versatile cells that are more quickly and easily coaxed to become induced pluripotent stem cells, or iPS cells, than are the skin cells most often used by researchers, according to a new study from Stanford’s School of Medicine. The findings were published online Monday in the Proceedings of the National Academy of Sciences.

“We’ve identified a great natural resource,” said Stanford surgery professor and co-author of the research, Michael Longaker, who has called the readily available liposuction leftovers “liquid gold.” Reprogramming adult cells to function like embryonic stem cells is one way researchers hope to create patient-specific cell lines to regenerate tissue or to study specific diseases in the laboratory.

“Thirty to 40 percent of adults in this country are obese,” agreed cardiologist Joseph Wu, the paper’s senior author. “Not only can we start with a lot of cells, we can reprogram them much more efficiently. Fibroblasts, or skin cells, must be grown in the lab for three weeks or more before they can be reprogrammed. But these stem cells from fat are ready to go right away.”

Longaker is the deputy director of Stanford’s Stem Cell Biology and Regenerative Medicine Institute and director of children’s surgical research at Lucile Packard Children’s Hospital. Wu is an assistant professor of cardiology and radiology, and a member of Stanford’s Cardiovascular Institute (…)

Even those of us who are not obese would probably be happy to part with a couple of pounds (or more) of flab. Nestled within this unwanted latticework of fat cells and collagen are multipotent cells called adipose, or fat, stem cells. Unlike highly specialized skin-cell fibroblasts, these cells in the fat have a relatively wide portfolio of differentiation options — becoming fat, bone or muscle as needed. It’s this pre-existing flexibility, the researchers believe, that gives these cell an edge over the skin cells (…)

Sun found that the fat stem cells actually express higher starting levels of two of the four reprogramming genes than do adult skin cells — suggesting that these cells are already primed for change. When he added all four genes, about 0.01 percent of the skin-cell fibroblasts eventually became iPS cells but about 0.2 percent of the fat stem cells did so — a 20-fold improvement inefficiency.

The new iPS cells passed the standard tests for pluripotency: They formed tumors called teratomas when injected into immunocompromised mice, and they could differentiate into cells from the three main tissue types in the body, including neurons, muscle and gut epithelium. The researchers are now investigating whether the gene expression profiles of the fat stem cells could be used to identify a subpopulation that could be reprogrammed even more efficiently (…)

from http://news.xinhuanet.com/english/2009-09/08/content_12011915.htm

Incoming search terms:

Alessandra Sacco

A study on mice directed by Alessandra Sacco of Stanford University has shown that once inserted into a diseased muscle, just one adult muscular stem cell can reproduce to form an entire ‘family’ of cells and restore lost muscular function. In a leg muscle with no muscular stem cells that has been irreversibly damaged, a single adult stem cell can take root and multiply, restoring muscular function.

The study was presented today in the Annual Meeting of the American Society of Cell Biology
(ASCB) in San Francisco. The muscular stem cells in this case are called ‘satellite cells’, which normally repair muscular tissue when it is damaged. In many degenerative muscular diseases however, this ‘natural repair’ is lacking and the muscular fibers degrade slowly. The validity of stem cell transplants into diseased muscle has been demonstrated on more than one occasion, but this is the first time that a single cell transplant has been performed.
The stem cell family born from the single cell was able to repair the muscle and restore its function, another step forward in stem cell research to cure degenerative muscular diseases.

Incoming search terms:

Baldness is an undesirable condition that afflicts both men and women, many of which have family members with significant hair loss. According to Health Day News, a new study of stem cells in mice shows promise for future treatments for people who battle hair loss.

The study was conducted on the fatty skin layers of mice by researchers at Yale University. Specifically, adipose precursor cells were found to spur new hair growth in mice, according to Health Day News.

Stem cells are present in hair follicles, which help generate hair growth. Health Day News explains that these cells are still present in people with baldness, but the follicles no longer receive signals to grow new hair. At the same time, hair loss causes a decrease in natural fat cells within the scalp.

“If we can get these fat cells in the skin to talk to the dormant stem cells at the base of the hair follicles, we might be able to get hair to grow again,” said senior study author Valerie Horsley, as quoted by Health Day News.

Incoming search terms:

Stem cells extracted from body fat may pave the way for the development of new regenerative therapies including soft tissue reconstruction following tumor removal or breast mastectomy surgery, the development of tissue-engineered cartilage or bone, and the treatment of cardiovascular disease.

An interdisciplinary team of Queen’s University researchers led by Dr. Lauren Flynn, a professor in the Departments of Chemical Engineering and Anatomy and Cell Biology, has been working with stem cells extracted from samples of human fat and is developing new methods in the lab to develop these cells into mature tissue substitutes.

While stem cells extracted from fat cannot be grown into as many different types of cells as embryonic stem cells, they do have a number of advantages.

“The advantages include less ethical controversy, abundant cell availability from discarded tissues from elective surgeries like breast reductions and tummy tucks, and a much reduced possibility for immune rejection when re-implanting cells extracted from a person’s own fat,” explains Dr. Juares Bianco, a postdoctoral fellow in the Department of Chemical Engineering and the Human Mobility Research Centre (HMRC) who is working in the Flynn lab group.

Incoming search terms: