METTL3‐m⁶A methylase regulates the osteogenic potential of bone marrow mesenchymal stem cells in osteoporotic rats via the Wnt signalling pathway

Abstract

Objectives Bone marrow mesenchymal stem cells (BMSCs) hold a high osteogenic differentiation potential, but the mechanisms that control the osteogenic ability of BMSCs from osteoporosis (OP‐BMSCs) need further research. The purpose of this experiment is to discuss the osteogenic effect of Mettl3 on OP‐BMSCs and explore new therapeutic target that can enhance the bone formation ability of OP‐BMSCs. Materials and Methods The bilateral ovariectomy (OVX) method was used to establish the SD rat OP model. Dot blots were used to reveal the different methylation levels of BMSCs and OP‐BMSCs. Lentiviral‐mediated overexpression of Mettl3 was applied in OP‐BMSCs. QPCR and WB detected the molecular changes of osteogenic‐related factors and Wnt signalling pathway in vitro experiment. The staining of calcium nodules and alkaline phosphatase detected the osteogenic ability of OP‐BMSCs. Micro‐CT and histological examination evaluated the osteogenesis of Mettl3 in OP rats in vivo. Results The OP rat model was successfully established by OVX. Methylation levels and osteogenic potential of OP‐BMSCs were decreased in OP‐BMSCs. In vitro experiment, overexpression of Mettl3 could upregulate the osteogenic‐related factors and activate the Wnt signalling pathway in OP‐BMSCs. However, osteogenesis of OP‐BMSCs was weakened by treatment with the canonical Wnt inhibitor Dickkopf‐1. Micro‐CT showed that the Mettl3(+) group had an increased amount of new bone formation at 8 weeks. Moreover, the results of histological staining were the same as the micro‐CT results. Conclusions Taken together, the methylation levels and osteogenic potential of OP‐BMSCs were decreased in OP‐BMSCs. In vitro and in vivo studies, overexpression of Mettl3 could partially rescue the decreased bone formation ability of OP‐BMSCs by the canonical Wnt signalling pathway. Therefore, Mettl3 may be a key targeted gene for bone generation and therapy of bone defects in OP patients.

Methyltransferase‐like 3 modulates osteogenic differentiation of adipose‐derived stem cells in osteoporotic rats

“…53 BMSCs. 54 Yao et al found that METTL3 played a significant role in BMSC differentiation and that low expression of METTL3 can promote the differentiation of BMSCs into adipose cells. 55 The osteogenic differentiation and adipogenic differentiation of BMSCs are in a dynamic balance, with enhanced adipogenic differentiation and reduced osteogenic differentiation.…”

“…Wu et al found that the methylation levels and osteogenic potential of OP‐BMSCs were reduced in OP‐BMSCs. Overexpression of Mettl3 could partially save the reduced bone formation ability of OP‐BMSCs 54 . Yao et al found that METTL3 played a significant role in BMSC differentiation and that low expression of METTL3 can promote the differentiation of BMSCs into adipose cells 55 .…”

Comprehensive analysis of the m6A-related molecular patterns and diagnostic biomarkers in osteoporosis

“…In particular, the m6A targets were significantly enriched in module brown, then an m6A regulator–target gene–pathway network in module brown was constructed, which contained two m6A regulators (METTL3 and YTHDF2), four m6A targets (SMAD4, HIPK3, MAP4K3, and EGFR), and 19 signaling pathways, such as MAPK, Foxo, PI3K-Akt, focal adhesion, Rap1 signaling pathway, Ras, calcium, cellular senescence, and TGF-beta signaling pathways. METTL3 promotes the osteogenic potential of mesenchymal stem cells in OP ( 28 , 56 , 57 ), while YTHDF2 has rarely been found in OP. SAMD4 and EGFR play critical roles in osteoprogenitor maintenance and bone formation ( 58 , 59 ).…”

Wnt10b regulates osteogenesis of adipose‐derived stem cells through Wnt/β‐catenin signalling pathway in osteoporosis

“…The Wnt pathway is thought to be an essential regulator of bone homeostasis. 16,17 and is composed of different ligands, coreceptors, receptors, and inhibitors. In a previous study, we performed GeneChip on OP-ASCs and ASCs and found that compared with ASCs, the expression of the Wnt10b RNA was significantly reduced in OP-ASCs (Figure 1D).…”

“…β-catenin is essential for Wnt10b, Wnt10a and Wnt6 to regulate osteoblastogenesis and adipogenesis. 17,18 Thus, β-catenin as a downstream factor is required for these Wnt ligands to regulate MSC fate. 19 Therefore, Wnt10b is an important gene in the Wnt ligand family that encodes a secreted protein to regulate the bone metabolism.…”