Therapeutic potential of microRNA in tendon injuries

Introduction: The regulatory role of microRNA (miRNA) in several conditions has been studied, but their function in tendon healing remains elusive. This review summarizes how miRNAs are related to the pathogenesis of tendon injuries and highlights their clinical potential, focusing on the issues related to their delivery for clinical purposes. Sources of data: We searched multiple databases to perform a systematic review on miRNA in relation to tendon injuries. We included in the present work a total of 15 articles. Areas of agreement: The mechanism of repair of tendon injuries is probably mediated by resident tenocytes. These maintain a fine equilibrium between anabolic and catabolic events of the extracellular matrix. Specific miRNAs regulate cytokine expression and orchestrate proliferation and differentiation of stromal cell lines involved in the composition of the extracellular matrix. Areas of controversy: The lack of effective delivery systems poses serious obstacles to the clinical translation of these basic science findings. Growing point: In vivo studies should be planned to better explore the relationship between miRNA and tendon injuries and evaluate the most suitable delivery system for these molecules. Areas timely for developing research: Investigations ex vivo suggest therapeutic opportunities of miRNA for the management of tendon injuries. Given the poor pharmacokinetic properties of miRNAs, these must be delivered by an adequate adjuvant transport system.