Most notably, these molecules are commonly found in animals known for being able to regrow limbs and other body parts, including salamanders, lizards, and zebrafish.
Scientists have discovered that humans have an innate or "salamander-like" ability to regenerate cartilage, which could lead to treatments for diseases such as osteoarthritis - and possibly provide a starting point for human limb regeneration.
"We believe we could boost these regulators to fully regenerate degenerated cartilage of an arthritic joint", says Kraus.
The study says that researchers can determine the missing regenerative factors in humans.
Salamanders, axolotls, and other animals with regenerative abilities have a type of molecule called microRNA that helps regulate joint tissue fix. "We suddenly started noticing that the ankle proteins tended by and large to be much younger than the same proteins in the knee and the same proteins in the hip", Kraus tells The Guardian.
The study also found that the "age" of cartilage - meaning whether proteins have changed structure or undergone amino acid conversions - depends on its location in the body.
Using mass spectrometry techniques on 18 specimens, researchers were able to identify a mechanism by which we fix tissue around our ankles, knees and hips - and it's similar to the mechanism amphibians use to sprout new legs.
The discovery of the cartilage fix mechanism was surprising in that it is found to be more effective in ankle joints, but less so in hips. "We call it our "inner salamander" capacity". Interestingly, it also matches up with animals with regenerative abilities, where regeneration usually happens more easily at the tips of the body, not the core.
Contrary to what scientists previously thought, a new study has found that humans can actually "counteract cumulative damage" in their joints through a process that's similar to the one used by animals that can re-grow limbs, according to a new study published on Wednesday in the journal Science Advances. Potentially, she suggests, microRNAs could be "injected directly into a joint to boost fix to prevent osteoarthritis after a joint injury or even slow or reverse osteoarthritis once it has developed". These microRNAs could be developed as medicines that might prevent, slow or reverse arthritis. This correlation between the age of human cartilage and its location in the body is similar to limb fix that occurs in certain animals, which regenerates faster at its furthest reaches.
The next step is to figure out what regulators humans lack that salamanders have - and then see if it's possible to "add the missing components back", said Duke professor Virginia Byers Kraus, one of the lead authors in the study.
"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 fix joint tissues and possibly whole human limbs", said senior author Virginia Byers Kraus, M.D., Ph.D., a professor in the departments of Medicine, Pathology and Orthopedic Surgery at Duke.