Seeking Molecular Signatures of Ectopic Bone Formation
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Impact Science, in response to an article in the November 4, 2020 JBJS.
Among military personnel who sustain blast-related injuries, physicians have observed a dramatic increase in the incidence of heterotopic ossification (HO), a pathology in which bone grows abnormally within soft tissues. This condition is frequently observed in association with burns and nonmilitary orthopaedic trauma, and combat-related HO is now occurring at an exceptionally high frequency of approximately 60%.
HO can range from an asymptomatic, incidental finding to a debilitating condition causing chronic pain and impaired movement. Although symptomatic HO is usually treated with surgical excision, identifying HO early in its development could go a long way toward improving quality of life for those with combat injuries.
Previous studies have suggested that certain microRNAs (miRNAs) play an important role in the formation of post-traumatic HO. A group of US researchers recently hypothesized that specific miRNA “signatures” might be present in the tissues of military personnel soon after a blast injury.
The authors collected 10 tissue samples from injured servicemembers during the surgical debridement of their wounds, about 8 days after the initial injuries occurred. The miRNA profiling of the samples, performed using a real-time polymerase chain reaction array, revealed that the tissues from patients who developed HO had upregulated levels of 6 miRNAs previously thought to take part in various bone-formation processes. Moreover, when some of those miRNAs were introduced into cultures of mesenchymal progenitor cells, the researchers found that 2 specific miRNAs (miR-1 and miR-206) were the most robust osteogenic “enhancers.” Interestingly, those same 2 miRNAs were found to target the downstream transcription factor SOX9, a deficiency of which can lead to a skeletal malformation syndrome.
These findings show that there are indeed early molecular signatures in the tissues of patients whose injuries progress to HO. While these novel insights into the molecular mechanisms underlying the development of HO may open doors to new therapeutic possibilities, Takamitsu Maruyama, PhD, in a commentary on the findings, cautions that modulating miR-1 and miR-206 “could affect not only HO formation but also the bone-healing process.”
Impact Science is a team of highly specialized subject-area experts (Life Sciences, Physical Sciences, Medicine & Humanities) who collaborate with authors, societies, libraries, universities, and various other stakeholders for services to enhance research impact. Through research engagement and science communication, Impact Science aims at democratizing science by making research-backed content accessible to the world.