The expression characteristics of miR-206-3p in musculoskeletal tissue and its clinical significance.

Abstract

Osteosarcopenia, a comorbidity of osteoporosis and sarcopenia in the elderly, involves bone-muscle crosstalk, but its core molecular mechanism remains unclear. miR-206 is traditionally considered muscle-specific; this study explores miR-206-3p's expression in musculoskeletal tissue and correlation with clinical parameters. A prospective cohort of 158 elderly hip fracture patients (79 osteosarcopenia, 79 controls) was enrolled. qRT-PCR, in situ hybridization, and scRNA-seq were used to analyze miR-206-3p's expression, distribution, and cell specificity. Correlations with grip strength, gait speed, and BMD were assessed. miR-206-3p was significantly downregulated in both tissues of the osteosarcopenia group (P < 0.001), highly expressed in Myod1⁺ muscle satellite cells and Runx2⁺ osteoprogenitor cells (> 82%), and weakly in mature cells (< 12%). It positively correlated with grip strength, gait speed, and BMD (r = 0.562-0.682, P < 0.001). miR-206-3p is co-expressed in bone-muscle progenitor cells, with synchronous downregulation linked to functional decline, challenging its "muscle-specific" notion and serving as a key molecular hub for bone-muscle crosstalk.