The addition of two particular gene snippets to a skin cell’s usual genetic material is enough to turn that cell into a fully functional neuron, report researchers from the Stanford University School of Medicine. The finding, published online July 13 in Nature, is one of just a few recent reports of ways to create human neurons in a lab dish.
The new capability to essentially grow neurons from scratch is a big step for neuroscience research, which has been stymied by the lack of human neurons for study. Unlike skin cells or blood cells, neurons are not something that’s easy for a living human to donate for research.
“A major problem in neurobiology has been the lack of a good human model,” said senior author Gerald Crabtree, MD, professor of pathology and of developmental biology. “Neurons aren’t like blood. They’re not something people want to give up.”
Generating neurons from easily accessible cells, such as skin cells, makes possible new ways to study neuronal development, model disease processes and test treatments.
It also helps advance the effort, still in its infancy, to replace damaged or dead neurons with new ones.
New technique removes several hurdles in generating induced pluripotent stem (iPS) cells, smoothing the way for disease research and drug development.
Stem cells are ideal tools to understand disease and develop new treatments; however, they can be difficult to obtain in necessary quantities. In particular, generating induced pluripotent stem (iPS) cells can be an arduous task because reprogramming differentiated adult skin cells into iPS cells requires many steps and the efficiency is very low – researchers might end up with only a few iPS cells even if they started with a million skin cells.
A team at Sanford-Burnham Medical Research Institute (Sanford-Burnham) set out to improve this process. In a paper published February 1 in The EMBO Journal, the team identified several specific microRNAs (miRNAs) that are important during reprogramming and exploited them to make the transition from skin cell to iPS cell more efficient.
“We identified several molecular barriers early in the reprogramming process and figured out how to remove them using miRNA,” said Tariq Rana, Ph.D., director of the RNA Biology program at Sanford-Burnham and senior author of the study. “This is significant because it will enhance our ability to use iPS cells to model diseases in the laboratory and search for new therapies.”
Incoming search terms:induced pluripotent stem cells company.
Mouse skin cells can be converted directly into cells that become the three main parts of the nervous system, according to researchers at the Stanford University School of Medicine. The finding is an extension of a previous study by the same group showing that mouse and human skin cells can be directly converted into functional neurons.
The multiple successes of the direct conversion method could refute the idea that pluripotency (a term that describes the ability of stem cells to become nearly any cell in the body) is necessary for a cell to transform from one cell type to another. Together, the results raise the possibility that embryonic stem cell research and another technique called “induced pluripotency” could be supplanted by a more direct way of generating specific types of cells for therapy or research.
This new study, published online Jan. 30 in the Proceedings of the National Academy of Sciences, is a substantial advance over the previous paper in that it transforms the skin cells into neural precursor cells, as opposed to neurons. While neural precursor cells can differentiate into neurons, they can also become the two other main cell types in the nervous system: astrocytes and oligodendrocytes. In addition to their greater versatility, the newly derived neural precursor cells offer another advantage over neurons because they can be cultivated to large numbers in the laboratory — a feature critical for their long-term usefulness in transplantation or drug screening.
In the study, the switch from skin to neural precursor cells occurred with high efficiency over a period of about three weeks after the addition of just three transcription factors. (In the previous study, a different combination of three transcription factors was used to generate mature neurons.) The finding implies that it may one day be possible to generate a variety of neural-system cells for transplantation that would perfectly match a human patient.
Incoming search terms:nano gel growing cartilage bone nose 2013, create nervous living.
A team of Harvard stem cell researchers has succeeded in reprogramming adult mouse skin cells directly into the type of motor neurons damaged in amyotrophic lateral sclerosis (ALS), best known as Lou Gehrig’s disease, and spinal muscular atrophy (SMA). These new cells, which researchers are calling induced motor neurons (iMNs), can be used to study the development of the paralyzing diseases and to develop treatments for them.
Producing motor neurons this way is much less labor intensive than having to go through the process of creating induced pluripotent stem cells (iPSC, iPS cells), and is so much faster than the iPS method that it potentially could reduce by a year the time it eventually takes to produce treatments for ALS and SMA, said Kevin Eggan, leader of the Harvard team.
Importantly, the direct reprograming does not involve the use of any factors known to trigger cancer or any other disease states, and the factors in fact make the fibroblasts, the connective tissue cells that make and secrete collagen proteins, stop dividing.
The work by Eggan, a member of the Harvard Stem Cell Institute principal faculty and an associate professor in Harvard’s Department of Stem Cell and Regenerative Biology (SCRB), and his colleagues builds on and advances work by SCRB co-chair and Professor Doug Melton, who pioneered direct cellular reprogramming, and Marius Wernig of Stanford, who used direct reprogramming to produce generalized neurons.
Incoming search terms:stem cell therapy filetype ppt:, Amyotrophic lateral sclerosis clinical professor Dr email @, islet cell transplant australia, kyle knopes 2013, stem cell treatment for spinal muscular atrophy in India.
New technique produces one hundred-fold increase in efficiency in reprogramming human cells
Researchers from the Wellcome Trust Sanger Institute have today (10/10/2011) announced a new technique to reprogramme human cells, such as skin cells, into stem cells. Their process increases the efficiency of cell reprogramming by one hundred-fold and generates cells of a higher quality at a faster rate.
Until now cells have been reprogrammed using four specific regulatory proteins. By adding two further regulatory factors, Liu and co-workers brought about a dramatic improvement in the efficiency of reprogramming and the robustness of stem cell development. The new streamlined process produces cells that can grow more easily.
“This research is a milestone in human stem cells,” explains Wei Wang, first author on the research from the Wellcome Trust Sanger Institute. “Our technique provides a foundation to unlock the full potential of stem cells.”
Stem cells are unspecialized cells that are able to renew themselves through cell division and can be induced to become functional tissue- or organ-specific cells. It is hoped that stem cells will be used to replace dying or damaged cells with healthy, functional cells. This could have wide-ranging uses in medicine such as organ replacement, bone replacement and treatment of neurodegenerative diseases.
Incoming search terms:surgan dr rajput cell tranceplant in delay milestone.