MicroRNAs in osteoporosis: current evidence and clinical perspectives

Osteoporosis, a widespread skeletal disorder, is defined by low bone mineral density and elevated fracture risk. Although dual-energy X-ray absorptiometry is the diagnostic standard, its limitations drive the search for novel biomarkers. MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression at the post-transcriptional level, play important roles in bone remodelling and the pathogenesis of osteoporosis. They influence cell differentiation, proliferation, and apoptosis, and their dysregulation contributes to bone metabolism disorders. MiR-133a promotes osteoclastogenesis and inhibits osteogenesis, while miR-214-3p suppresses osteogenesis by targeting factors such as osterix. MiR-125b is upregulated in osteoporosis, negatively affecting osteogenic markers, and miR-21-5p shows complex, context-dependent effects on bone cells. Emerging candidates include miR-483-5p, miR-497-5p, and miR-422. These molecules provide insight into osteoporosis mechanisms and hold potential as diagnostic and therapeutic targets. Although miRNA-based therapies are promising, further studies are required to validate the findings and improve delivery strategies. Advances in miRNA research may enable earlier diagnosis and more effective osteoporosis treatment.