Millions of people suffering from the grinding pain of osteoarthritis may soon have new hope beyondpainkillers and joint replacement surgery. Researchers, led by Dr. Nidhi Bhutani, havediscovereda method to regrow knee cartilage by blocking a single protein that accumulates as we get older.
A team at Stanford Medicine has found that a simple injection can trigger the regrowth of cartilage in mice and human tissue samples. The study, published in the journal 'Science', suggests that it is possible to trick the body into healing itself, even after years of wear and tear.
The breakdown of cartilage is the main cause of osteoarthritis, a condition that affects about one in five adults in the US and millions more across the UK and EU. Cartilage is the smooth, rubbery tissue that cushions bones at the joints. Once it wears away, it usually does not grow back. This leads to bone rubbing against bone, causing swelling, pain, and difficulty moving.
The researchers discovered that aspecific enzyme, known as 15-PGDH, plays a villainous role in this process. Levels of this enzyme are much higher in older joint tissue. Its main job seems to be destroying a helpful molecule called prostaglandin E2, which tells the body to repair injuries.
When the scientists blocked 15-PGDH, the repair signals were able to resume their function. Dr. Bhutani tracked the regrowth, and her team found that inhibiting the enzyme allowed the cartilage layer to thicken and rebuild across the knee surface.
What makes this discovery distinct from previous attempts to cure arthritis is how it works. In the past, scientists have tried to inject stem cells—blank slate cells that can turn into any type of tissue—into the knee. However, this new method does not require adding anything new to the body.
Instead, the treatment 'rewires' the cells that are already there. These cells, called chondrocytes, are responsible for maintaining cartilage. In older knees, these cells often switch into a destructive mode or turn into scar tissue.
The inhibitor drug acts like a reset button. It convinces the chondrocytes to stop breaking down tissue and start building it again. The study found that the repaired tissue acted just like normal, healthy cartilage. It was able to support weight and movement without stiffening the joint.
'The mechanism is quite striking and really shifted our perspective about how tissue regeneration can occur,' Dr. Bhutani said regarding the findings.
This research is particularly good news for athletes and younger people who suffer knee injuries. A tear in the anterior cruciate ligament (ACL) is a common sports injury. Even after surgery, about half of people with an ACL tear will develop osteoarthritis within five to 15 years.
Source: International Business Times UK
