Say Cheese!

Researchers at the University Of Michigan School Of Dentistry in Ann Arbior and Karolinska institute in Stockholm, Sweden may have good reason to smile. Their work on detail pulp cell innervations could have positive ramifications on the study of spinal cord cell regeneration after injury. The researcher are growing dental cells in the lab and closely monitoring the process that leads to the growth and development of nerves r within those cells that eventually leads to the formation of proper nerve connections in teeth. The future then hold the promise that a tooth could be extracted dental cells grown and implanted into patients suffering from spinal cord damage or Parkinson S’ Reason enough to smile, right?

(Development Biology October 2001)

 Embryonic Stem Cell Transformed into blood cells

A link between mice and men? In a way yes, we and our furry friends are pretty similar at the cellular level! Using this Similarity to work on transforming embryonic stem cell into blooding-  forming cells were researchers from the university of Wisconsin, Madison, headed by James Thompson PhD. Since the signal that turns embryonic stem cells into blood forming cell were researchers from the University of Wisconsin, Madison headed by James Thompson, PhD. Since the signals that turn embryonic cells into primitive blood calls are not yet known, the researchers grew the embryonic stem cells in the presence of blood – forming cells derived from a mouse hoping that the similarity at the cellular level would produce a positive result. And it did, the chemical signals released by the mouse blood cells presumably were recognised by the human embryonic stem cells and taken as a cue to change into blood forming cells of the bone marrow. The stem cells grew into colonies that were primed to make red blood cells, white blood cells and platelets. This first step is a great achievement. The Wisconsin researchers now need to show that their blood forming cells can be grafted into bone marrow and form an endless source of new blood cells. So far, experiments on mice have shown that mice embryonic stem cells derived blood forming cells have failed to properly engraft and produce new blood cells. However, the future holds a lot of promise since this work lays the foundation for new therapies using laboratory – made tissues and organ from embryonic cells. Over time if hematopoietic stem cells could be derived from human embryonic cells, not only could they provide a plentiful source of bone marrow transplant for the many patients who cannot find matched donors, they could also establish tolerance in the patient to other tissues, such as a heart or pans\creatic islets made in the laboratory from the same line of embryonic cells. This experiment was described in September 11, 2001 issue of the proceeding of the National Academy of Sciences.

Adult Stem Cells Transplants – will they be the answer to transplants for human disease in the future?

Embryonic stem cell transplants and possible treatment are considered to be the corner stone in the treatment of many diseases because of their remarkable ability to differentiate into any kind of tissue .  But  researchers at  Karolinska  Institute in Stockholm,  Sweden have  come up with   some exciting  findings  involving  stem  cells  from  the brain s of adult mice.    They showed that these stem cells can could be matured into heart, liver, muscle and other tissues and could be make their way to appropriate body locations. Jonas Trisen, PhD and his colleagues removed stem cells from the central nervous system of adult mice. Genetically engineered them to carry an easily traceable marker and injected them into mouse and chicken embryos.  They found that the transplanted cells not only took up residence on the embryos brain s and spinal tissues, but were also converted into a variety of other body tissues and organs.  The conversion   rate was only 12% or less and the marked cells were not detected in many places, the bone marrow being one of them.  However, other experiments on adult mice have shown that neural stem cells can differentiate into various blood cells.

A number of questions still need to be answered:

Can adult stem cells be used to grow new organs or to treat diabetes, Parkinson’s and Alzheimer’s. What was the nature of the signal that prompted the neural stem cells to become different types of tissues?

But the exciting part, as Freisen and his colleagues say is that all the combined research to date indicate that “stem cells in different adult tissues may be more similar than previously thought and perhaps in some cases have a developmental repertoire close to that of embryonic stem cells” .

An Alternative to Neural Stem Cell Transplants?

 "Is it possible to induce signals that will recruit stem cells right in the brain where they are without transplantation to make new neurons in the cerebral cortex?"

This is question that lead investigator Jeffery Macklins PHD from Harvard university medical school, Boston USA asked.’ The finding from their experiment on mice were reported in the June 2000issue of nature and the answer was YES in small number  Neural stem Cells could be made differentiate into mature  neurons  in regions of the cerebral cortex that normally did not undergo neurogensis. A combination and sequence of the molecular control signals direct stem cell to repair the brain from the inside out. These signals direct cells to migrate to exactly the right location to differentiate into the right kind neurons and too survive. The future is exciting but it is still a long way off from human application. The researcher team will be working first to uncover the combination and sequence of the system with specific growth factors to try to increase the rate of new neuron production.

Macklis thinks that by increasing the number of stem cells or guiding then more efficiently many more appropriate new neurons could be made. He also thinks that in the next decade the neurons that are affected in spinal cord injury or ALS clinical benefit from approach. This is because a relatively small number of imperfectly imprecisely wired neurons could make the difference between the lack of function altogether and some kind of function imperfect though it may be.

 However treatment for the diseases like Parkinson’s or Alzheimer’s is decades away because of the need for absolute precision of neuron wiring.