Osteoarthritis: We too can regrow joint tissues like salamanders|study

Last updated on June 12th, 2020 at 10:42 am

New research that can benefit millions of osteoarthritis knee pain sufferers has found that humans also have the capability to regrow joint cartilage through a process similar to regenerating limb by zebrafish.

The study was published on an online journal Science Advances, and researchers found that human joint cartilage has salamander-like regenerative capacity which can be used as a foundation for a new approach for the treatment of osteoarthritis knee.

In this article, we will dig deeper into the research and what made scientists conclude that humans can also regrow joint cartilage similar to zebrafish regrowing its damaged limb.

Salamander-like regrowing capability

Some animals, such as zebrafish, bichir, and axolotl, have a high regenerative capacity, they can regenerate their damaged fin, tails, and limbs. We all must have seen how lizard in our house can regrow its damaged tail.

This regeneration capability depends on the process termed by researchers as a protein-turnover. The higher the protein-turnover on a particular limb, the higher would be the capability to regenerate.

The process of protein-turnover is in turn regulated by microRNA believed to be present in animals known for limb, fin or tail repair.

Unlike these animals, humans cannot regenerate whole limbs. Humans are also believed to be unable to counteract the cumulative damage of repetitive joint use or one substantial, usually sports- or trauma-related injury that leads to the breakdown of cartilage and the development of osteoarthritis (OA).

Still, previous studies have discovered progenitor cells residing in mature cartilage that gives the regenerative capacity of articular cartilage.

What present study reveals?

The present study reveals that the microRNA that regulates protein-turnover (which in turn regulates the limb regeneration) in animals is also present in the human being, the only difference is they are more active in animals.

The research further reveals that the process of protein-turnover is positional dependent. This means the protein-turnover gradient is more in the distal joint (ankle) the proximal joint (knee and hip joint).

This is further supported by previous findings pointing towards the higher prevalence of hip and knee OA compared with ankle OA, particularly the rarity of severe ankle OA, and the lower prevalence of surface fibrillation of ankle cartilage with age compared with knee cartilage.

Together, these data suggest a role for regenerative miRNA in cartilage homeostasis, turnover, and intrinsic repair capacity.

Also read: Rheumatoid arthritis vs osteoarthritis: which arthritis is worse?

What does it mean for us?

The researchers said microRNAs could be developed as medicines that might prevent, slow or reverse arthritis.

“We believe we could boost these regulators to fully regenerate degenerated cartilage of an arthritic joint. If we can figure out what regulators we are missing compared with salamanders, we might even be able to add the missing components back and develop a way someday to regenerate part or all of an injured human limb,” Kraus said. “We believe this is a fundamental mechanism of repair that could be applied to many tissues, not just cartilage.”

Till the research can actually benefit the OA knee sufferer, exercises for knee pain is most important and safest way out. In one of my articles, I have shared the list of 6 effective OA knee pain exercises which you may refer to.

Journal Reference:

1. Ming-Feng Hsueh, Patrik Önnerfjord, Michael P. Bolognesi, Mark E. Easley, Virginia B. Kraus. Analysis of “old” proteins unmasks dynamic gradient of cartilage turnover in human limbs. Science Advances, 2019; 5 (10): eaax3203 DOI: 10.1126/sciadv.aax3203