It has long been thong that c in human joints cannot repair itself. New research finds that this is not the case, and that this is not the case and that cartilage can be re-grown through a process that closely follows the self-repair abilities of salamanders and zebrafish. These animals can to regenerate limbs, which is not something that humans can do. However, the mechanisms used can trigger cartilage re-growth, according to scientists working at Duke University Medical Center.
With the research, the scientists developed a means to assess the age of proteins by examining the internal molecular clocks integral to amino acids (which can convert one form to another). This showed that newly created proteins in tissue have very few amino acid conversions. In contrast, older proteins have many conversions.
By learning about this process, the scientists were able to deploy mass spectrometry in order to identify when key proteins in human cartilage, such as collagens, were young compared to when they were old. This is regulated by molecules called microRNA.
This revealed that the age of cartilage was dependent upon where it was located in the body. For example, the cartilage found in the ankles is young, older in the knee and very old in the hips. This aligns with how limb repair occurs in certain animals, such as salamanders, where regeneration is easier at the furthest tips, as with the ends of legs or tails. It is thought that the cells from the salamander’s different tissues retain the “memory” of the original tissues when they regenerate, which explains why only to the same type of tissue develops.
This insight explains why injuries to a person’s knees and hips takes a long time to recover and why there is a risk of developing arthritis in these areas.
According to lead researcher Dr. Virginia Byers Kraus: “We believe that an understanding of this ‘salamander-like’ regenerative capacity in humans, and the critically missing components of this regulatory circuit, could provide the foundation for new approaches to repair joint tissues and possibly whole human limbs.”
Based on the finding it appears possible that microRNAs can be developed as medicines that might prevent, slow or reverse arthritis.
The research has been published in the journal Science Advances, with the research paper titled “Analysis of “old” proteins unmasks dynamic gradient of cartilage turnover in human limbs.”
In relation to the creatures that provided inspiration for the research, salamanders are at risk in China due to the animals being favored for food. It now stands that Chinese giant salamanders are classified as critically endangered, where the animals were once widespread throughout central, southern and eastern China.
