miR-216a rescues dexamethasone suppression of osteogenesis, promotes osteoblast differentiation and enhances bone
1Department of Cell Biology, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Peking Union Medical College Hospital, Center of Excellence in Tissue Engineering Chinese Academy of Medical Sciences, Beijing, China.
Abstract:
Osteoporosis is a disease marked by reduced bone mass, leading to an increased risk of fractures or broken bones. Bone formation is mediated by recruiting mesenchymal stem cells (MSCs). Elucidation of the molecular mechanisms that regulate MSC differentiation into osteoblasts is of great importance for the development of anabolic therapies for osteoporosis and other bone metabolism-related diseases. microRNAs (miRNAs) have been reported to have crucial roles in bone development, osteogenic differentiation and osteoporosis pathophysiology. However, to date, only a few miRNAs have been reported to enhance osteogenesis and regulate the suppressive effect of glucocorticoids on osteogenic differentiation. In this study, we discovered that miR-216a, a pancreatic-specific miRNA, was significantly upregulated during osteogenic differentiation in human adipose-derived MSCs (hAMSCs). The expression of miR-216a was positively correlated with the expression of bone formation marker genes in clinical osteoporosis samples. Functional analysis demonstrated that miR-216a can markedly promote osteogenic differentiation of hAMSCs, rescue the suppressive effect of dexamethasone (DEX) on osteogenic differentiation in vitro and enhance bone formation in vivo. c-Cbl, a gene that encodes a RING finger E3 ubiquitin ligase, was identified as a direct target of miR-216a. Downregulation of c-Cbl by short hairpin RNAs can mimic the promotion effects of miR-216a and significantly rescue the suppressive effects of DEX on osteogenesis. Pathway analysis indicated that miR-216a regulation of osteogenic differentiation occurs via the c-Cbl-mediated phosphatidylinositol 3 kinase (PI3K)/AKT pathway. The recovery effects of miR-216a on the inhibition of osteogenesis by DEX were attenuated after blocking the PI3K pathway. Thus, our findings suggest that miR-216a may serve as a novel therapeutic agent for the prevention and treatment of osteoporosis and other bone metabolism-related diseases.
Insights
A novel microRNA, miR-216a, promotes bone formation by enhancing osteoblast differentiation. This discovery offers a potential new therapy for osteoporosis and related bone diseases, even counteracting drug-induced bone loss.
Area of Science:
- Molecular Biology
- Stem Cell Biology
- Endocrinology
Background:
- Osteoporosis is characterized by low bone mass and increased fracture risk.
- Mesenchymal stem cell (MSC) differentiation into osteoblasts is key to bone formation.
- MicroRNAs (miRNAs) play critical roles in bone metabolism, but few are known to promote osteogenesis or counteract glucocorticoid effects.
Purpose of the Study:
- To investigate the role of miR-216a in osteogenic differentiation and its therapeutic potential for osteoporosis.
- To elucidate the molecular mechanisms underlying miR-216a's function in bone formation.
Main Methods:
- Expression analysis of miR-216a in human adipose-derived MSCs (hAMSCs) during osteogenic differentiation and in clinical osteoporosis samples.
- In vitro functional assays to assess miR-216a's effect on hAMSC osteogenic differentiation and its interaction with dexamethasone (DEX).
- In vivo studies to evaluate miR-216a's impact on bone formation.
- Identification of miR-216a targets and pathway analysis using molecular biology techniques.
Main Results:
- miR-216a was upregulated during osteogenic differentiation and positively correlated with bone formation markers in osteoporosis patients.
- miR-216a significantly promoted osteogenic differentiation of hAMSCs, rescued DEX-induced suppression in vitro, and enhanced bone formation in vivo.
- c-Cbl was identified as a direct target of miR-216a, and its downregulation mimicked miR-216a's effects.
- miR-216a's mechanism involves the c-Cbl-mediated phosphatidylinositol 3 kinase (PI3K)/AKT pathway.
Conclusions:
- miR-216a promotes osteogenic differentiation and bone formation.
- miR-216a can counteract the negative effects of glucocorticoids on bone metabolism.
- miR-216a represents a promising therapeutic target for osteoporosis and other bone diseases.
