Stem cell therapies hold promise, but obstacles remain

The journal Science has an article by a group of researchers, including a neurologist Steve Goldman, M.D., Ph.D. from University of Rochester reviewing the potential and challenges the scientific community faces, as therapies involving stem cells start becoming reality.

This review article talks about pluripotent stem cells (PSCs), which are the stem cells that can produce all cell types. These include embryonic stem cells, and the cells derived from mature cells.

The process of “reprogramming” or “inducing” means using a patient’s own skin cells to make sure that so that the stem cells possesses similar characteristics as the patient.

These cells are then differentiated to turn into virtually any and all cell types found in the body. It takes careful manipulation of the chemical and genetic signaling of the cell. While this process is relatively new when put in scientific terms “ it was first demonstrated in 2007, that the skin cells could be successfully reprogrammed.

This is one of the reasons that these cells promise of serving the purpose and are most favored by the scientific community as they are derived from the patient’s own tissue.

Consequently, stem cells presents the doctors with the most ideal choice for transplant as they are a perfect genetic match and are much less likely to be rejected.

Thus it mitigates the need to use any immune system suppressing medication or drugs.

There are a number of diseases that might be treated successfully by the use of PSCs, including diabetes, liver diseases and heart problems. This article addresses the current efforts that are being diverted to apply PSCs to eradicate these diseases completely. The current state of therapies for neurological diseases is being reviewed by a distinguished professor and co-director of the University of Rochester School of Medicine and Dentistry Center for Translational Neuromedicine, Goldman.

The authors say that despite significant progress in this field, over the last several years, there are still concrete challenges that remain ahead. In order to treat any of the mentioned diseases, scientists need to obtain the precise cell populations that will be enough to treat them. Also that once these cells are transplanted, they need to ensure that these cells get to the location where they are needed the most

and get integrated into the existing tissue. These cells also have to be first checked for purity and then screened for unwanted cells and other particles that may cause tumors.

Goldman alongwith his co-authors claim that “the brain is arguably the most difficult of the organs in which to employ stem cell-based therapeutics.” The central ervous system has a rather complex network of connections and interdependency. The neurons and other support cells are very well connected and a precise and matching reconstruction of the damaged parts of the human brain is practically impossible.

They also pointed out that many degenerative neurological disorders, such as Alzheimer’s disease that involve more than one type of brain cells, makes for a difficult target for stem cell therapy. Thus it is argued by Goldman that neurological diseases that affect only a single cell type are without a doubt more promising targets for PSC-based therapies.

These diseases are Parkinson’s disease and Huntington’s disease. They occur when the brain looses dopamine-producing neurons and medium spiny neurons, respectively. In particular, diseases that involved support cells found in the

brain known as glia “ such as multiple sclerosis, white matter stroke, cerebral palsy, and pediatric leukodystrophies “ are especially strong candidates for stem cell therapies.

Diseases that cause loss of a glial cell type are called the oligodendrocyte. In multiple sclerosis, the body’s immune system is responsible for the loss of these cells as it attacks and destroys them.

Oligodendrocytes are produced by another cell called the oligodendrocyte progenitor cell, or OPC.

Scientists speculate that a successful transplant into the diseased or injured brain might help OPCs to produce new oligodendrocytes.

References

https://www.biomedcentral.com/1741-7015/9/52/

https://www.nature.com/nm/journal/v10/n7s/full/nm1064.html