Circulating MiR-181c-5p and MiR-497-5p Are Potential Biomarkers for Prognosis and Diagnosis of Osteoporosis

Context: Osteoporosis is a degenerative bone disease in aging men and women. MiRNAs associated with progressive bone loss in osteoporosis had not been clearly demonstrated.

Objective: The evaluation of the differentially expressed miRNAs in the bone tissue and serum of osteoporotic women with aging.

Methods: MiRNAs GeneChip and real-time PCR were used to screen differently expressed miRNAs in bone tissues of 21 osteoporotic women ages 60-69 years and 80-89 years. Identified miRNAs were detected in the serum of the validation cohort, which consisted of 14 healthy premenopausal women and 86 postmenopausal women with osteopenia or osteoporosis. MiR-181c-5p and miR-497-5p expression were validated in aging and OVX mice models, and osteoblasts. Their role in osteogenesis was validated in vitro.

Results: Twenty-four miRNAs showed the highest differential expression in bone tissues of osteoporotic women in initial screening. Among them, four miRNAs were identified both in the bone tissue and serum in the validation cohort. The levels of miR-181c-5p and miR-497-5p were decreased in the serum of postmenopausal women with osteopenia or osteoporosis, but increased in subjects treated with bisphosphonate plus calcitriol. MiR-181c-5p and miR-497-5p were significantly downregulated in the bone tissue of aging and OVX mice models, and upregulated during the osteogenic differentiation of hFOB1.19 and MC3T3-E1 cells. Overexpression of miR-181c-5p and miR-497-5p promoted the differentiation and mineralization of osteoblasts.

Conclusions: MiR-181c-5p and miR-497-5p are involved in bone metabolism and associated with progressive bone loss of due to osteoporosis, suggesting that circulating miR-181c-5p and miR-497-5p might act as potential biomarkers for monitoring the effects of antiosteoporotic therapies or the diagnostic approach.