SEP 08, 2017 2:19 PM PDT

Interpreting Mixed Signals to Stem Cells

WRITTEN BY: Carmen Leitch

The protein TAZ (PDZ-binding motif), has many roles in various cellular processes, including organ development and cell growth or proliferation. There has been a lot of research interest in the protein because it is apparently disrupted in cancer, and it has a central role in the communication of chemical messages in the cell. New work has revealed that TAZ can send different signals to different cells. The research has been published in Stem Cell Reports.

The protein TAZ (green) in the cytoplasm (the region outside of the nuclei, blue) promotes the self-renewal of human embryonic stem cells. / Credit: Xingliang Zhou/Ying Lab, USC Stem Cell

This work used mouse embryonic stem cells, which have the potential to become any type of specialized cell in the organism; but until they do, they are considered naïve. They are not the only kind of stem cell though. Some are set to become specific types of specialized cells when they differentiate. One example in mice is mouse epiblast stem cells (EpiSCs). Human ESCs seem to be this kind of primed cell too, and may not be true ESCs after all.

Researchers in the laboratory of Qi-Long Ying at the University of Southern California, including doctoral candidate Xingliang Zhou, have now shown that in naïve mouse ESCs the TAZ protein is not needed for self-renewal or the production of more stem cells. However, the stem cells do require TAZ so they can differentiate into mouse EpiSCs.

The researchers also uncovered a more subtle role of TAZ in the primed types of stem cells. In mouse EpiSCs and in human ESCs, if TAZ is hanging out in the nucleus, primed stem cells will then differentiate into more specialized kinds of cells. That is similar to what naïve cells do. But if TAZ is located in the area of the cell between the nucleus and outer membrane, or if it is in the cytoplasm, then primed stem cells react oppositely by self-renewing.

"TAZ has stirred up a lot of controversy in our field because it appears to produce diverse and sometimes opposite effects in pluripotent stem cells," explained senior author Ying, an Associate Professor of Stem Cell Biology and Regenerative Medicine. "It turns out that TAZ can indeed produce opposite effects, depending upon both its subcellular location and the cell type in question."

"TAZ provides a new tool to stimulate stem cells to either differentiate or self-renew. This could have important regenerative medicine applications, including the development of a better way to generate the desired cell types for cell replacement therapy,” concluded Zhou, the first author of the work. 

Learn more about the different functions and abilities of stem cells, including self-renewal and differentiation, from the above lecture by Elaine Fuchs, a Howard Hughes Medical Investigator. 

 

Sources: AAAS/Eurekalert! Via USC, Physiology Reviews, Stem Cell Reports

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
DEC 18, 2019
Drug Discovery & Development
DEC 18, 2019
Stroke Drug Enhances Stem Cell Therapies for Spinal Cord Injuries
Using rat models of spinal cord injuries, Yasuhiro Shiga, MD, PhD, thought treating them with stem cell therapy would point to nowhere but the nature of re...
DEC 30, 2019
Neuroscience
DEC 30, 2019
Amyloid Plaques May Not Come First in Alzheimer's
It’s commonly thought that excessive build-up of amyloid plaques, destroying the connections between nerve cells, is the first sign of Alzheimer&rsqu...
JAN 04, 2020
Immunology
JAN 04, 2020
Why Do Skincare Products Sometimes Cause Rashes?
Chemicals commonly found in skincare products are intended to avoid interactions with the part of the immune system responsible for triggering allergic inf...
FEB 03, 2020
Microbiology
FEB 03, 2020
The Switch Controlling the Stage of a Common Parasite
The parasite Toxoplasma gondii is thought to infect from one-quarter to one-third of the global population....
FEB 05, 2020
Cell & Molecular Biology
FEB 05, 2020
Gut Bacteria Affect How the Colon Moves
The contraction and relaxation of muscles in the wall of the colon helps move food along and can become dysfunctional....
FEB 09, 2020
Cell & Molecular Biology
FEB 09, 2020
Switching Inflammation Off at the Molecular Level
While chronic inflammation is a natural result of getting old, experiencing stress, and toxin exposure, it's been theorized to be the basis for many chronic diseases....
Loading Comments...