Featured Research

from universities, journals, and other organizations

Chemical signaling simulates exercise in cartilage cells

Date:
January 13, 2014
Source:
Duke Medicine
Summary:
Cartilage is notoriously difficult to repair or grow, but researchers have taken a step toward understanding how to regenerate the connective tissue. By adding a chemical to cartilage cells, the chemical signals spurred new cartilage growth, mimicking the effects of physical activity.

In these cartilage cells, fluorescent dyes measure changes in the concentration of calcium in response to mechanical loading. Green indicates areas of high calcium, while red indicates areas of low calcium within each cell.
Credit: Duke Medicine

Cartilage is notoriously difficult to repair or grow, but researchers at Duke Medicine have taken a step toward understanding how to regenerate the connective tissue. By adding a chemical to cartilage cells, the chemical signals spurred new cartilage growth, mimicking the effects of physical activity.

Related Articles


The findings, published online in the Proceedings of the National Academy of Sciences the week of Jan. 13, 2014, point to an ion channel called TRPV4 as a potential target for new therapies to treat osteoarthritis or even regrow cartilage.

Articular cartilage is the tissue that lines joints such as hips, knees and shoulders, providing cushioning and smooth movement. Similar to bones and muscles, cartilage only stays healthy and strong through loading, or applying force, through physical activity.

Abnormal forces on the joints can cause a variety of problems leading to pain and loss of mobility. Overloading joints through overuse or injury can lead to the cartilage breaking down, while lack of use can result in cartilage wasting through atrophy. Both kinds of cartilage deterioration leave joints prone to osteoarthritis, a degenerative and debilitating disease.

Until recently, researchers did not know how cartilage converts mechanical loading into the ion channel signals that promote growth. Understanding how cartilage senses mechanical loading could equip researchers with the knowledge needed to prevent or better treat joint diseases.

"Mechanical loading plays a critical role in the overall health of the cartilage," said Farshid Guilak, Ph.D., Laszlo Ormandy Professor of Orthopaedic Surgery at Duke and the study's senior author. "If we can figure out how cartilage cells sense mechanical loads, we can trick them into thinking they are being exercised or stop them from responding to abnormal loading. Think of it as artificial exercise for your cartilage."

In the study, led by MD/PhD student Christopher O'Conor, the researchers looked at articular cartilage cells from pigs and focused on TRPV4, an ion channel abundant in cartilage cells that can be turned on during mechanical loading. When the researchers "exercised" the cartilage cells using mechanical loading, the cells sensed the loading and grew cartilage tissue. When they added a compound that blocked TRPV4, essentially turning off signals from the ion channel, the cartilage did not grow and the effects of the mechanical loading were lost.

Next, the researchers substituted mechanical loading for a chemical that activated TRPV4. Without having to exercise the cartilage, they observed the growth of cartilage even more so than with the mechanical loading. The findings suggest that TRPV4 is responsible for sensing mechanical loading in the cartilage.

Now that they know that turning on TRPV4 can simulate the effects of mechanical loading in cartilage cells, the researchers are looking at ways to harness this potential.

"Our next step is to see if this synthetic 'exercising' technology works on human cells that could be used to regrow new human cartilage," said O'Conor, who is completing his MD/PhD degree at the University of North Carolina at Chapel Hill and is performing his dissertation work with Guilak in the Duke Orthopaedic Bioengineering Laboratories.

Beyond growing new cartilage, the researchers will investigate whether the compounds that activate or block TRPV4 could act as new therapies to prevent cartilage degeneration and joint disease.


Story Source:

The above story is based on materials provided by Duke Medicine. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. J. O'Conor, H. A. Leddy, H. C. Benefield, W. B. Liedtke, F. Guilak. TRPV4-mediated mechanotransduction regulates the metabolic response of chondrocytes to dynamic loading. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1319569111

Cite This Page:

Duke Medicine. "Chemical signaling simulates exercise in cartilage cells." ScienceDaily. ScienceDaily, 13 January 2014. <www.sciencedaily.com/releases/2014/01/140113152625.htm>.
Duke Medicine. (2014, January 13). Chemical signaling simulates exercise in cartilage cells. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2014/01/140113152625.htm
Duke Medicine. "Chemical signaling simulates exercise in cartilage cells." ScienceDaily. www.sciencedaily.com/releases/2014/01/140113152625.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins