Mice that don’t produce lubricin, a thin film of protein found in the cartilage of joints, showed early wear and higher friction in their joints, a new study led by Brown University researchers shows.
This link between increased friction and early wear in joints is a first; no other team of scientists has proven this association before. The finding, published in Arthritis & Rheumatism, sheds important light on how joints work. The discovery also suggests that lubricin, or a close cousin, could be injected directly into hips, knees or other joints inflamed from arthritis or injury – a preventive treatment that could reduce the need for painful and costly joint replacement surgery.
In an editorial that accompanies the journal article, orthopedics researchers from Rush University Medical Center in Chicago call the research an “important contribution to the field” and note that the use of biomolecules like lubricin to prevent joint wear “could have a substantial clinical impact, if successful.”
Gregory Jay, M.D, a Rhode Island Hospital emergency physician and an associate professor of emergency medicine and engineering at Brown, led the research. For 20 years, Jay has studied lubricin’s role as a “boundary lubricant” by reducing friction between opposing layers of cartilage inside joints. In this new work, Jay and his colleagues set out to answer the next question: Does reducing friction actually prevent wear, or surface damage, in joints?
To find out, Jay and his team studied cartilage from the knees of mice that don’t produce lubricin. Directly after birth, the cartilage was smooth. But in as little as two weeks, researchers found, the cartilage began to show signs of wear. Under an electron microscope, scientists could see that the collagen fibers that cartilage is composed of were breaking up, giving the surface a rough, frayed appearance. This damage is called wear, an early sign of joint disease or injury.
Jay and his team then took the work a step further. To better understand how lubricin works, they tried to see the structure of the film. So they put a tiny bit of the protein under an atomic force microscope. At the nanoscale, the molecule appeared as a mesh – row upon row of interlocking fibers – that could repel a microscope probe. This repulsion, created with water and electrical charges, shows how lubricin acts as a buffer, keeping opposing layers of cartilage apart.
“We demonstrated that lubricin reduces both friction and wear and also showed how, on a molecular level, it does this work in the body,” Jay said. “What’s exciting are the clinical implications. Arthritis and sports injuries damage the joints of thousands of people in the United States and millions of people worldwide each year. Our aim is to make a treatment that can actually prevent wear in the joints.”
Through Rhode Island Hospital, Jay has filed two patents on the protein and its sequences and, in 2004, helped form Tribologics, a biotech company formed out of Rhode Island Hospital. The Massaschusetts-based business is developing an injection treatment for inflamed joints that contains lubricin.
Members of the research team included Jahn Torres, a former Brown graduate student in engineering; David Rhee, a former graduate student at Case Western Reserve University; Heikki Helminen, M.D., and Mika Hytinnen, M.D., from the University of Kuopio in Finland; Chung-Ja Cha, a research assistant at Rhode Island Hospital; Khaled Elsaid, a postdoctoral research fellow at Rhode Island Hospital; Kyung-Suk Kim, a professor of engineering at Brown; and Yajun Cui, M.D., and Matthew Warman, M.D., of Boston Children’s Hospital and Harvard Medical School.
The National Institute of Arthritis and Musculoskelatal and Skin Diseases funded the work, along with the Academy of Finland, the McCutchen Foundation, the Howard Hughes Medical Institute and the Burroughs Wellcome Fund.
Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews and maintains an ISDN line for radio interviews. For more information, call the Office of Media Relations at (401) 863-2476.
Wendy Lawton | EurekAlert!
Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University
New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Physics and Astronomy
21.03.2018 | Materials Sciences
21.03.2018 | Life Sciences