Exercise helps to prevent the degradation of cartilage caused by osteoarthritis, according to UK researchers, who have identified the mechanism behind it for the first time.
They have shown how mechanical forces experienced by cells in joints during exercise prevent cartilage degradation by suppressing the action of inflammatory molecules that cause osteoarthritis, potentially opening up new approaches to preventive treatment.
“We have known for some time that healthy exercise is good for you – now we know the process”
Their study, published in the journal Osteoarthritis and Cartilage, demonstrates the benefits of exercise on the tissues that form joints due to tiny hair-like structures called primary cilia found on living cells.
During exercise the cartilage in joints such as the hip and knee is squashed, noted the researchers from Queen Mary University of London.
This mechanical distortion is detected by the living cells in the cartilage which then block the action of inflammatory molecules associated with conditions such as arthritis.
The researchers found this anti-inflammatory effect of physical activity was caused by activation of a particular protein, called HDAC6, which triggers changes in the proteins that form primary cilia.
Pharmaceutical drugs that blocked HDAC6 activation prevented the anti-inflammatory effects of physical activity, while other drug treatments were able to mimic the benefits of exercise.
Changes in length of the primary cilia, which are only a few 1000th of a millimetre, provided a biomarker of the level of inflammation, noted the researchers.
Cilia got longer during inflammation, but treatments that prevented this elongation successfully prevented inflammation, according to the study authors.
“These findings may also explain the anti-inflammatory effects of normal blood flow in arteries”
Study author and PhD student Su Fu said: “We have known for some time that healthy exercise is good for you – now we know the process through which exercise prevents cartilage degradation.”
Professor Martin Knight, lead researcher on the study, added: “These findings may also explain the anti-inflammatory effects of normal blood flow in arteries which is important for preventing arterial disease such as atherosclerosis and aneurism.”
The researchers said they hoped that their findings would help in the search for treatments for arthritis which affects over three million people in the UK causing stiff and painful joints.
They also suggested that the results may lead to a whole new therapeutic approach known as mechano-medicine, in which drugs simulate the effect of mechanical forces to prevent the damaging effects of inflammation and treat conditions such as arthritis.