Stem Cell Research

Researchers Transform Mouse Skin Cells Into Neurons, Skipping Induced Pluripotent Stem Cell Stage

The future of regenerative medicine continues to depend on the type of stem cell that is proven most effective, most scalable, and most time and cost efficient to produce.  Approaches include embryonic stem cells, adult stem cells, Induced pluripotent stem cells, from both autologous and allogeneic sources.  One of our Sector Companies, International Stem Cell Corp., is attempting to create a stem cell bank based on parthenogenic stem cells derived from unfertilized eggs (oocytes).  Such a bank would have the following advantages:

1. A scalable bank would contain a manageable number of stem cell lines that will be immunological matches for large patient populations of different ethnic origin.


2. Unlike induced pluripotent stem (iPS) cells these would not involve extensive gene manipulation, which to this point in time have largely unknown biological impact.

We point this out in order to ask ourselves what the potential impact on such a stem cell bank might be from new study results obtained by researchers at Stanford University.  Since human iPS cells were first created in late 2007, the emphasis has been on developing these cells in a faster, cheaper way that also provides safe and predictable biological results when used in regenerative therapies.

But what if the iPS phase can be skipped entirely?  Will adult cells converted, for example, directly  into nerve cells be an eventual solution to Parkinson's Disease?  Or will parthenogenic, or some other more basic, more embryonic-like, cell provide the answer.  Perhaps both will be a solution and success in the market, as well as in therapy, will be a function of efficiency from origin to therapeutic use, and resultant lower cost. Perhaps neither will be universally useful in general therapy, but will be more effective for therapies in particular parts of the body.  At this stage no one knows for sure.  What we do know is that knowledge is expanding rapidly as shown in this current Stanford study.

Stanford researchers have succeeded in transforming mouse skin cells in a laboratory dish directly into functional nerve cells with the application of just three genes. The cells make this transition without first becoming a pluripotent type of stem cell.

Geron Recieves FDA Approval To Begin World's First Human Clinical Trial of An Embryonic Stem Cell-Based Therapy

This is Monday after the Friday morning announcement of the first Phase I trial of an embryonic stem cell therapy.  At this writing Geron's market cap ($645M) is now greater than that of Osiris Therapeutics ($619M).  Osiris is in Phase III trials with Prochymal (not for spinal cord repair), a mesenchymal stem cell therapeutic application derived from adult bone marrow stem cells.  Everything points to Osiris obtaining approval to market Prochymal by the end of 2010.  Prochymal will in all probability be the first stem cell therapeutic application approved for market distribution.

Geron's market cap totaled $415 million at close of market on Thursday.  This morning it hit $650 million before ending the day around $645M.  This $230 million or so increase in market cap is the direct result of the FDA acceptance of the idea (based on the largest investigational drug application - 22,000 pages - ever submitted) that embryonic stem cells are safe enough to test in a small number of human beings (8 to 10 people is the test size).

Stem Cells And Spinal Cord Injuries

Researchers have found that manipulating stem cells prior to transplantation may hold the key to overcoming a critical obstacle to using stem cell technology to repair spinal cord injuries.

This particular research focused on a major support cell in the central nervous system called an astrocyte. When nerve fibers are injured in the spinal cord, the severed ends of the nerve fibers fail to regenerate and reconnect with the nervous system circuitry beyond the site of the injury. During early development, astrocytes are highly supportive of nerve fiber growth, and scientists believe that if properly directed, these cells could play a key role in regenerating damaged nerves in the spinal cord.

Computational Biology Shows Greater RNA Interference (RNAi) Role In Stem Cell Differentiation

In hopes of shedding light on the process of cancer initiation, neurodegenerative disorders, diabetes and other diseases, scientists have combined forces to learn how stem cell differentiation is controlled by microRNAs.

If you haven't read our previous posts, you're already asking yourself what RNA Interference (RNAi) is.  It's a term worth getting familiar with if you're interested in the developing arena of stem cell research and its potential for regenerative medicine.

A First: Embryonic Stem Cells Coaxed To Become Nerve Cells

One of the most difficult challenges in stem cell research is figuring out exactly what biological events cause stem cells to differentiate into specific, functioning cells in the body.  For nerve cells this mystery may now be solved. For the first time, researchers have genetically programmed embryonic stem (ES) cells to become nerve cells when transplanted into the brain.

Stroke, Alzheimer’s, Parkinson’s and Huntington’s disease destroy brain cells, causing speech and memory loss and other debilitating consequences. Transplanting neuronal brain cells could restore at least some brain function, just as heart transplants restore blood flow.  But until now there has been no reliable method of coaxing stem cells to become nerve cells.

“We found that we could create new nerve cells from stem cells, transplant them effectively and make a positive difference in the behavior of the mice,” said Stuart A. Lipton, M.D., Ph.D., professor and director of the Del E. Webb Neuroscience, Aging, and Stem Cell Research Center at The Burnham Institute. “These findings could potentially lead to new treatments for stroke and neurodegenerative diseases such as Parkinson’s disease.”

Study Finds Brain Stem Cells Can Be Awakened

 "Everyday experience leads us to suppose that thoughts pass through the mind with a rapidity that defies the laws of physics. It comes as a stunning surprise to discover that almost the exact opposite is true: the brain is slow—very slow— by comparison with the fundamental forces of the physical world," Jean-Pierre Changeux in The Physiology of Truth: Neuroscience and Human Knowledge.

Neurons use electricity to send signals through the body and brain. Early on it was thought that neurons connected directly with other neurons to allow the transmission. In the 1920s this assumption was found not to be true. Instead, there is generally a gap between communicating neurons. The gap is called the synaptic cleft and a chemical synapse carries the converted electrical signal across the synaptic cleft where it is reconverted into an electrical signal in the receptor neuron.  In terms of raw speed, it's a little like putting regularly spaced sand traps on a NASCAR race course. Chances for problems and quirks in this process are numerous.  The last thing it needs is an inability to replace diseased or destroyed neurons.