miR‐196b‐5p Regulates Osteoblast and Osteoclast Differentiation and Bone Homeostasis by Targeting SEMA3A

Abstract

ABSTRACTmiR‐196b‐5p plays a role in various malignancies. We have recently reported its function in regulating adipogenesis. However, it remains to be clarified whether and how miR‐196b‐5p affects bone cells and bone homeostasis. In this study, in vitro functional experiments showed an inhibitory effect of miR‐196b‐5p on osteoblast differentiation. Mechanistic explorations revealed that miR‐196b‐5p directly targeted semaphorin 3a (Sema3a) and inhibited Wnt/β‐catenin signaling. SEMA3A attenuated the impaired osteogenesis induced by miR‐196b‐5p. Osteoblast‐specific miR‐196b transgenic mice showed significant reduction of bone mass. Trabecular osteoblasts were reduced and bone formation was suppressed, whereas osteoclasts, marrow adipocytes, and serum levels of bone resorption markers were increased in the transgenic mice. The osteoblastic progenitor cells from the transgenic mice had decreased SEMA3A levels and exhibited retarded osteogenic differentiation, whereas those marrow osteoclastic progenitors exhibited enhanced osteoclastogenic differentiation. miR‐196b‐5p and SEMA3A oppositely regulated the expression of receptor activator of nuclear factor‐κB ligand and osteoprotegerin. The calvarial osteoblastic cells expressing the transgene promoted osteoclastogenesis, whereas the osteoblasts overexpressing Sema3a inhibited it. Finally, in vivo transfection of miR‐196b‐5p inhibitor to the marrow reduced ovariectomy‐induced bone loss in mice. Our study has identified that miR‐196b‐5p plays a key role in osteoblast and osteoclast differentiation and regulates bone homeostasis. Inhibition of miR‐196b‐5p may be beneficial for amelioration of osteoporosis. © 2023 American Society for Bone and Mineral Research (ASBMR).

Histone demethylase KDM7A regulates bone homeostasis through balancing osteoblast and osteoclast differentiation

“…Primary BMSCs were isolated from the marrow of 6-week-old mice and cultured following a previously described procedure [ 41 ]. Pre-osteoblastic cells were isolated from the calvaria of 3-day-old mice.…”

“…The cells were passaged at 80% confluence and those at passages 3–5 were induced to allow osteogenic and adipogenic differentiation following a previously published protocol [ 41 ]. In certain experiments aimed at investigating the underlying mechanisms, cells were treated with 200 ng/ml recombinant FAP (Sino Biological), or TC-E 5002 (MedChemExpress, USA), a selective inhibitor of the KDM2/7 subfamily, at doses of 10, 20 and 40 μmol/l.…”

“…Differentiated osteoblasts were subjected to ALP staining after 14 days of osteogenic induction, or to alizarin red staining after 21 days of induction as per a previously published procedure [ 41 ]. To quantify the intensity of the alizarin red staining, the stained cultures were destained with a solution containing 0.5 mol/L HCl and 5% SDS for 10 min, and the absorbance of the solution was read at 415 nm.…”

The effects of semaphorin 3A in bone and cartilage metabolism: fundamental mechanism and clinical potential

“…A recent investigation by Xie and colleagues has shed light on the regulatory role of miR-196b-5p, implicated in various malignancies, in osteoblast and osteoclast differentiation. Their findings suggest that miR-196b-5p exerts its influence by targeting Sema3A and impeding the Wnt-β-catenin signaling pathway (Xie et al, 2023). However, the role of the Wnt signaling system in osteogenic differentiation remains a subject of debate.…”