Nav: Home

In their DNA: Rotator cuff stem cells more likely to develop into fat cells

February 06, 2019

February 6, 2019 - Why are fat deposits more likely to occur after tears of the shoulder's rotator cuff, compared to other types of muscle injuries? An increased propensity of stem cells within with rotator cuff muscles to develop into fat cells may explain the difference, reports a study in the February 6, 2019 issue of The Journal of Bone & Joint Surgery. The journal is published in the Lippincott portfolio in partnership with Wolters Kluwer.

"Satellite" stem cells in the rotator cuff are more likely to develop into fat cells and less likely to develop into muscle cells, compared to calf muscle satellite cells, according to the experimental study by Christopher L. Mendias, PhD, ATC, and colleagues of the University of Michigan Medical School, Ann Arbor, and the Hospital for Special Surgery, New York. The researchers write, "There appears to be a cellular and genetic basis behind the generally poor rates of rotator cuff muscle healing."

'Satellite Cells' May Form More Fat Than Muscle after Rotator Cuff Tears

The researchers performed a series of experiments using muscle cells from mice to evaluate the characteristics of a type of stem cells called satellite cells. Stem cells are specialized cells with the potential to develop into different types of cells. Satellite cells, located between muscle fibers, play an essential role in repair after muscle injuries.

Tears of the shoulder rotator cuff are a common problem. Especially in chronic tears, deposits of fat often develop, contributing to weakening and atrophy of the rotator cuff muscles. This fatty infiltration can continue even after successful rotator cuff repair surgery.

Dr. Mendias and colleagues created cultures of satellite cells isolated from mouse rotator cuff and calf muscles. "Clinically, we know that the rotator cuff is one of the most difficult muscle groups to rehabilitate after injury, and this is thought to occur due to the extensive fat that accumulates in the muscle in patients with chronic tears," says lead author Manuel Schubert, MD, MS, chief resident in orthopaedic surgery at the University of Michigan. "We thought there might be a genetic basis to explain why the rotator cuff accumulates fat after injury, and the specialized transgenic model we used in this study allowed us to precisely test this." 

Compared to the calf muscle satellite cells, satellite cells from the rotator cuff developed into 23 percent fewer muscle cells, and they showed an 87 percent decrease in a "marker" for muscle formation. The rotator cuff satellite cells also had a four- to 65-fold increase in markers of genes involved in fat cell generation (adipogenesis).

DNA-level (epigenetic) studies identified hundreds of differences in gene activation between satellite cells from rotator cuff versus calf muscles. The affected genes were involved in pathways related to fat metabolism and adipogenesis, suggesting the muscle stem cells from the rotator cuff are programmed to more easily become fat cells.

Building on previous research, the new study shows increased "adipogenic differentiation capacity" of rotator cuff satellite cells. Increased potential to develop into fat cells - and decreased potential to develop into muscle cells - may be an important explanation for the high rate of fatty infiltration in muscles of patients with chronic rotator cuff tears, even after rotator cuff surgery.

The study also has potential therapeutic findings. "Satellite cells can be isolated from other muscle groups with relative ease." says Dr. Mendias, an Associate Scientist at the Hospital for Special Surgery and an Adjunct Associate Professor at the University of Michigan. "While further studies are necessary, it is possible that a patient's own stem cells from a muscle that heals well, like the calf, could be transplanted to the rotator cuff muscle at the time of surgical repair. These transplanted cells might be better able to regenerate the chronically damaged muscle than the resident stem cells."
-end-
Additional researchers who contributed to the study are Andrew Noah, MS, Jonathan Gumucio, PhD, and Asheesh Bedi, MD, all at the University of Michigan.

Click here to read "Reduced Myogenic and Increased Adipogenic Differentiation Capacity of Rotator Cuff Muscle Stem Cells"

DOI: 10.2106/JBJS.18.00509

About The Journal of Bone & Joint Surgery

The Journal of Bone & Joint Surgery (JBJS) has been the most valued source of information for orthopaedic surgeons and researchers for over 125 years and is the gold standard in peer-reviewed scientific information in the field. A core journal and essential reading for general as well as specialist orthopaedic surgeons worldwide, The Journal publishes evidence-based research to enhance the quality of care for orthopaedic patients. Standards of excellence and high quality are maintained in everything we do, from the science of the content published to the customer service we provide. JBJS is an independent, non-profit journal.

About Wolters Kluwer

Wolters Kluwer is a global leader in professional information, software solutions, and services for the health, tax & accounting, finance, risk & compliance, and legal sectors. We help our customers make critical decisions every day by providing expert solutions that combine deep domain knowledge with specialized technology and services.

Wolters Kluwer, headquartered in the Netherlands, reported 2017 annual revenues of €4.4 billion. The company serves customers in over 180 countries, maintains operations in over 40 countries, and employs approximately 19,000 people worldwide.

Wolters Kluwer Health is a leading global provider of trusted clinical technology and evidence-based solutions that engage clinicians, patients, researchers and students with advanced clinical decision support, learning and research and clinical intelligence. For more information about our solutions, visit http://healthclarity.wolterskluwer.com and follow us on LinkedIn and Twitter @WKHealth.

Wolters Kluwer 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

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab