Regenerative medicine biologists discover a cellular structure that explains fate of stem cells

July 01, 2015

DALLAS - July 1, 2015 - UT Southwestern Medical Center scientists collaborating with University of Michigan researchers have found a previously unidentified mechanism that helps explain why stem cells undergo self-renewing divisions but their offspring do not.

Adult stem cells provide a ready supply of new cells needed for tissue homeostasis throughout the life of an organism. Specialized environments called "niches" help to maintain stem cells in an undifferentiated and self-renewing state. Cells that comprise the niche produce signals and growth factors essential for stem cell maintenance. The mechanisms that allow for reception of these signals exclusively by stem cells and not their more specialized progeny remain poorly understood.

"This finding stands to change the way we think about how stem cells and their neighbors communicate with one another," said Dr. Michael Buszczak, Associate Professor in the Department of Molecular Biology and with the Hamon Center for Regenerative Science and Medicine.

The findings are presented in the journal Nature.

Scientists have been working to understand how the signaling between niches and stem cells works.

"These signals act over a short range, so only stem cells ? but not their differentiating progeny ? receive the self-renewing signals," said Dr. Buszczak, E.E. and Greer Garson Fogelson Scholar in Medical Research. "The mechanics of this communication were not known. What we discovered was that the stem cells form microtubule-based nanotubes, which extend into the niche. These threadlike nanotubes act like straws to tap into the niche and allow signaling to occur specifically in the stem cell."

The findings emanate from an active collaboration between the Buszczak lab at UT Southwestern and the lab of Dr. Yukiko Yamashita at the University of Michigan. Dr. Yamashita is an Associate Professor of Cell and Developmental Biology at the University of Michigan Life Sciences Institute and a Howard Hughes Medical Institute (HHMI) Investigator.

First author Dr. Mayu Inaba, a Postdoctoral Research Fellow at the Life Sciences Institute and a visiting Senior Fellow in Molecular Biology at UT Southwestern in the Buszczak lab, noticed thin projections linking individual stem cells back to a central hub in the stem cell "niche." Dr. Yamashita looked through her old image files and identified the same connections in numerous images. "I had seen them, but I wasn't seeing them," Dr. Yamashita said. Dr. Inaba worked to further develop the project as a senior research fellow in the Buszczak lab over the last several years.

The findings are important groundwork for understanding how stem cells reproduce and how miscommunication between cells can result in diseases like cancer. Too much stem cell production, for example, can lead to cancerous growth. Too little reproduction can result in inadequate renewal of cells and underlies the aging process.

The long-term goal of Dr. Buszczak's lab is to determine the complete regulatory network that controls both the maintenance of Drosophila stem cells and the differentiation of their daughters. "We hope to use this information as a foundation for understanding how perturbations in normal gene expression programs cause disease," Dr. Buszczak said.
The mission of the Hamon Center for Regenerative Science and Medicine is to impact human health through discoveries of the fundamental mechanisms of tissue formation and repair, and to use this knowledge to develop transformative strategies and medicines to enhance tissue regeneration. The Center is led by Dr. Eric Olson, Chair of Molecular Biology at UT Southwestern.

The research was supported by the HHMI and the MacArthur Foundation.

About UT Southwestern Medical Center

UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution's faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. The faculty of more than 2,700 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in 40 specialties to about 92,000 hospitalized patients and oversee approximately 2.1 million outpatient visits a year.

This news release is available on our home page at

To automatically receive news releases from UT Southwestern via email, subscribe at

UT Southwestern Medical Center

Related Stem Cells Articles from Brightsurf:

SUTD researchers create heart cells from stem cells using 3D printing
SUTD researchers 3D printed a micro-scaled physical device to demonstrate a new level of control in the directed differentiation of stem cells, enhancing the production of cardiomyocytes.

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.

Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.

First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.

Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.

The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.

Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.

New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.

NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.

Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.

Read More: Stem Cells News and Stem Cells Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to