Nav: Home

Scientists develop recipe for testosterone-producing cells

April 14, 2016

Researchers led by teams at the Johns Hopkins Bloomberg School of Public Health and Wenzhou Medical University of China have discovered a way to keep adult stem cells that are destined to become testosterone-producing cells multiplying and on track to fulfill their fate, a new study reports.

The findings could eventually help scientists develop transplantable cells that can churn out testosterone, avoiding the multitude of drawbacks associated with other ways to administer this quintessential male hormone. A report on the research is published online in the Proceedings of the National Academy of Sciences.

Scientists have long known that testosterone, produced by Leydig cells in the testicles, is necessary for the male reproductive system to develop in fetuses and to maintain male reproductive function later in life. More recent research has shown that testosterone performs a host of other critical jobs in the body, with deficiencies contributing to increased body fat, decreased muscle mass, increased fatigue, depressed mood, decreased cognitive function and reduced immune response. Low testosterone has also been linked to increased mortality risk in older men.

To combat these issues, and to synchronize secondary sexual characteristics with gender identity in transgendered men, doctors often prescribe testosterone supplements that can be administered a variety of ways, including injection or topically. But these methods have a number of side effects, including increased risk of heart attacks and strokes, prostate enlargement, breast enlargement and acne. These issues, says study leader Haolin Chen, Ph.D., senior scientist in the Department of Biochemistry and Molecular Biology at the Bloomberg School, stem from the dramatic peaks and valleys in blood concentrations of the hormone that result from artificial administration.

One way to avoid these issues would be to mimic the way the body naturally releases testosterone, with cells that release the hormone steadily over time. While Chen and his colleagues had been successful at isolating adult stem cells set to become Leydig cells, they were unsure how to keep the cells multiplying, a process known as proliferation, and additionally to direct them to be testosterone producers, a process known as differentiation.

In the new study, the researchers used a method they'd previously developed to keep the stem cells alive, culturing them along isolated sections of the tubes that carry sperm in the testicles known as seminiferous tubules. For the next several weeks, the researchers fed these samples with various growth factors and other proteins that previous research had suggested might play a role in proliferation and differentiation.

They found a variety of factors that stimulated proliferation, including the proteins desert hedgehog (DHH), basic fibroblast growth factor, platelet-derived growth factor and activin. DHH and activin also stimulated differentiation. The research also showed that DHH played a vital role in transforming the stem cells into fully functioning, testosterone-producing Leydig cells.

Additionally, Chen and his colleagues determined that a protein called CD90, found on cell surfaces, could reliably distinguish the stem cells on the surfaces of seminiferous tubules that could be steered into Leydig cells.

Together, Chen says, these findings could be useful both for basic research as a model system for stem cells in general, and also to someday help researchers to create a population of testosterone-producing cells fit for transplant by isolating the right stem cells, prompting them to multiply and then to differentiate into Leydig cells.

"Our work could eventually offer a whole new therapy for individuals with low testosterone," Chen says.

"Regulation of seminiferous tubule-associated stem Leydig cells in adult rat testes" was written by Xiaoheng Li, Zhao Wang, Zhenming Jiang, Jingjing Guoa, Yuxi Zhang, Chenhao Li, Jinyong Chung, Janet Folmer, June Liu, Qingquan Lian, Renshan Ge, Barry R. Zirkin, and Haolin Chen.
-end-


Johns Hopkins University Bloomberg School of Public Health

Related Stem Cells Articles:

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.
In mice, stem cells seem to work in fighting obesity! What about stem cells in humans?
This release aims to summarize the available literature in regard to the effect of Mesenchymal Stem Cells transplantation on obesity and related comorbidities from the animal model.
TSRI researchers identify gene responsible for mesenchymal stem cells' stem-ness'
Researchers at The Scripps Research Institute recently published a study in the journal Cell Death and Differentiation identifying factors crucial to mesenchymal stem cell differentiation, providing insight into how these cells should be studied for clinical purposes.
Stem cells in intestinal lining may shed light on behavior of cancer cells
The lining of the intestines -- the epithelium -- does more than absorb nutrients from your lunch.
More Stem Cells News and Stem Cells Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.