Much work is being done on human limb regeneration concentrating on the specific microRNA circuit used by zebrafish, bichirs, and axolotls to regulate the regrowth of amputated extremities. Unfortunately, humans cannot regenerate whole limbs and are also believed to be unable to counteract the breakdown or damage of cartilage and the development of osteoarthritis. Now, a study from Duke University shows cartilage in human joints can repair itself through a process similar to the limb-regenerating mechanism possessed by salamanders and zebrafish. The team states they identified a mechanism for human cartilage repair more robust in ankle joints and less so in hips. The opensource study is published in the journal of Science Advances.
Previous studies have shown for animals with the capacity of whole-limb regeneration, blastema formation at the site of limb injury is critical. Also called Regeneration Bud, a blastema is a mass of undifferentiated cells with the capability to develop into an organ or a limb. Most recently, an important blastema miRNA regulatory circuit shared by three highly regenerative animal systems has been shown to control limb regeneration. The current study investigates whether miRNA, critical for blastema formation during limb regeneration across species, plays a role in articular cartilage protein turnover in humans.
The current study extracts RNA from the human ankle, knee, and hip cartilages to assess whether humans share any of the evolutionarily conserved miRNA essential for limb regeneration in highly regenerative animals. The group devised a way to test for regeneration by determining the age of proteins, and by extension the cartilage they form, based on how many conversions their amide group has gone through, also known as deamidation. Results show newly created proteins in tissue have few or no amino acid conversions, whereas older proteins have many; with this cartilage regeneration regulated by microRNA.
Data findings show the age of cartilage largely depends on where it resides in the body; cartilage in ankles is young, it’s middle-aged in the knee and old in the hips. The lab states this correlates with how limb repair occurs in certain animals, which more readily regenerate at the ends of legs or tails. They go on to add they quantified the blastema-relevant miRNA, namely miR-21, miR-31, and miR-181c, expression in cartilage, with miR-21 shown to be the most highly expressed miRNA of the three.
The team surmises they have successfully profiled the regional patterns of protein turnover and miRNA expressions responsible for human joint cartilage regeneration. For the future, the researchers state an understanding of this ‘salamander-like’ regenerative capacity in humans could provide the foundation for new approaches to repair joint tissues and possibly whole human limbs.
Source: Duke University Medical Center
Get Healthinnovations delivered to your inbox:
Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.
Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.
Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio, BioPortfolio.com, the life science, pharmaceutical and healthcare portal.
Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.
Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.
An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.