Health,Stem Cells, and Technology

Saturday, May 21, 2011

Proteins Follow RNA That Follow DNA: Oops, This Dogma Is Not Necessarily So

The 'central dogma' of molecular biology: that the sequence of bases encoded in DNA determines the sequence of amino acids that makes up the corresponding proteins. But now research by Dr. Vivian Cheung, professor at the University of Pennsylvania, suggest that human cells may complicate this long held belief more often than previously thought by making many proteins that do not match their underlying DNA sequences.

In this week's Science, Professor Cheung, who studied microbiology at UCLA and obtained her MD at Tufts University in Boston, and her team found more than 10,000 places where the base (A, C, G or U) in a cell's RNA messages is not the one expected from the DNA sequences used to make the RNA read-out. When many of these mismatched RNAs were subsequently translated into proteins, the proteins reflected the non-matching RNA sequences rather than that of the underlying DNA.

Data has shown for many years that many cells 'edit' RNA after it has been produced to give a new coding sequence, but Cheung's new work suggests that such editing occurs much more often in human cells than anyone had realized, and that hitherto unknown editing mechanisms must be involved to produce some of the changes observed. If the finding is confirmed by other investigators, and some scientists already say they see the same phenomenon in their own data, this new concept will change biologists' understanding of the cell and alter the way researchers study genetic contribution to disease.

As I have said in my previous publications (e.g. Maguire et al, 2006, 2007), genomics without other levels of analysis such as proteomics, metabolomics, transciptomics, along with anatomical and physiological data of different sorts is absolutely required to understand human biology and disease states. Systems biology analysis at several levels is needed to understand normal human function and disease function.

Monday, May 16, 2011

Some Induced Pluripotent Stem Cells May Encounter Immune Rejection Problems?

Dr Yang Xu, professor of biology at UC San Diego, and his research team have discovered that an important class of stem cells known as induced pluripotent stem cells (iPSCs), derived from an individual’s own mature cells, induced immune rejection in a mouse model.
Reported today in the journal Nature, the researchers report the first clear evidence of immune system rejection of cells derived from quasi-autologous iPSCs.
Because iPSCs are not derived from embryonic tissue and are not subject to the federal restrictions that limit the use of embryonic stem cells, and because these cells can be derived from the patient's own tissue, researchers regard them as one promising means to develop stem cell therapies. Because iPSCs are derived from an individual’s own cells, many scientists had hoped that these stem cells would not be recognized by the immune system. As a consequence, the immune system would not develop an attack to purge iPSCs from the body.
Further, some scientists regarded iPSCs as particularly attractive candidates for clinical use because cells derived from embryonic stem cells sometimes induce immune system rejection that requires physicians to administer immune suppressant medications that can compromise a person’s overall health.
But the UCSD biologists, funded by NIH and an early translational grant from the California Institute for Regenerative Medicine, the state’s stem-cell funding agency, found that iPSCs are subject to some of the same problems of immune system rejection as embryonic stem cells.. 
The scientists found, not surprisingly, that the immune system of one mouse could not recognize the cells derived from embryonic stem cells of the same strain of mice. But the experiments also showed that the immune system rejected cells derived from iPSCs reprogrammed from fibroblasts of the same strain of mice, thought to mimic the situation whereby a patient would be treated with cells derived from iPSCs reprogrammed from the patient’s own cells. 
Although these are animal studies, and were not performed in a strictly autologous procedure, these data, along with previously mentioned data from other studies, do suggest that iPSCs are not the same as embryonic stem cells. Autologous stem cell procedures using adult stem cells remain a more powerful means for clinical therapies until we better understand the iPSCs.

Friday, May 13, 2011

BioRegenerative Sciences, Inc. To Present Stem Cell Data At Society For Neuroscience Annual Meeting

Stem Cell-Based Systems Biology Approach For Developing Therapeutics To Manage Peripheral Pain.

Presented by Greg Maguire and Peter Friedman at the Society for Neuroscience Annual Meeting 2011

Natural healing processes in the human body utilize adult stem cells to home-in and localize damaged tissue, and then release a multitude of molecules to orchestrate a healing cascade of events in the damaged target tissue. The healing cascade induced by adult stem cells is a naturally occurring systems biology-based therapeutic regimen.   Mimicking this natural healing process utilized by adult stem cells, we have developed topically applied formulations containing the multitude of molecules released by the adult stem cells, called stem cell released molecules (SRM), to induce a healing process, and a reduction in pain and inflammation when topically applied to the skin, eyes, and mucosal tissue.

Recent studies demonstrate that two or more stem cell types act in concert to induce healing. Therefore, we utilized a combination of adult stem cell types from the native tissue to derive our SRM; thus when the SRM from two or more stem cell types was used to formulate our topical products, we called this S2RM. Analytical testing showed the molecules released from the adult stem cells were manyfold, including growth factors, interleukins, cytokines, anti-oxidants, and a number of other factors. Animal and human testing showed that the molecules induced no irritation and no cytotoxic effects. Laboratory and clinical testing in humans and canine models showed that pain reduction could be achieved rapidly and effectively in all tissues tested, including keratoconjunctival tissue, intact injured skin, ulcerated skin wounds, and mucosa. Rapid and continuous long-term healing of the tissue was associated with a rapid and continuous long-term pain relief. Current studies are underway to explore the mechanisms underlying the healing, anti-inflammatory, and pain relieving properties of the S2RM technology.

Key words: Stem cells, stem cell released molecules, pain, peripheral pain, SRM, skin, cornea, mucosa

Wednesday, May 11, 2011

Intel To Manufacture New Tri-Gate Transistor Invented At UC Berkeley

This week, computer chip manufacturer Intel announced that it is preparing to enter the third dimension in transistor design. Known as Tri-Gate, Intel's new transistor will be the first to go into mass production with a truly three-dimensional (3D) structure.

Intel says that the transistor will offer performance and efficiency benefits over 2D models when the chip goes into production later this year. Power savings and a 37% increase in speed over 2D chips is said to be realized with the 3D design. Some industry analysts call it a risky venture, but this was said when Intel brought to market the first Pentium chips back in the 1990s.

The Tri-Gate design is a variant of a 'FinFET' 3D structure developed in the late 1990s by Dr. Chenming Hu and his colleagues at the University of California, Berkeley. Professor Hu received his PhD at UC Berkeley and has authored or co-authored three books and 800 research papers and has supervised 60 doctoral students in the field of semiconductor technology. 

Intel believes the Tri-Gate structure should scale down to transistors of 14 nanometres and smaller. In principle, chip design therorists believe implementation of transistors, 3D or otherwise, of just a few atoms should be possible, although manufacturing consistency becomes ever more difficult as size diminishes.

At some point, manufacturers will be forced to explore yet more dimensions. Perhaps at that stage the answer will be spintronics, which is an emerging technology that makes use of an electron's spin and charge. As an example of the interest in this new generation technology, the US Air force has invested over $7 million at the University of California, Santa Barbara to study spintronics and quantum computing.

Saturday, May 7, 2011

Restoring Light Sensation But Not Vision In Blind Mice

Recent laboratory studies at the University of Southern California have shown that viral vectors can deliver light-sensitive proteins to specific cell types in the retinas of blind mice, allowing rudimentary light sensation. Previous studies have shown that the light-sensitive proteins can be beneficial, but the delivery methods were not practical for human application. The new viral-delivery method in the current study is similar to ones already used in human gene therapy.
The new virally inserted light-sensitive proteins were active for the length of the study, roughly 10 months, suggesting the treatment may work long-term. Further, the therapy appeared safe. The foreign proteins that were derived from algae, remained functional within the eye, and did not trigger inflammation.
Although the studies are very scientifically very advanced and suggest methods for possible therapeutics, using this method in an attempt to restore vision will not work in its current form. This is because much of the visual processing occurs distal to where the new proteins were expressed, and this distal information processing will not be restored in the current methods. So while these methods will restore light sensitivity to the retina, other methods will be required to restore vision.
A much better approach to visual restoration in patients with distal retinal atrophy, such as in retinitis pigmentosa, will be the use of stem cell therapeutics; I'll have more to say about this in an upcoming blog.