MFN2 knockdown promotes osteogenic differentiation of iPSC-MSCs through aerobic glycolysis mediated by the Wnt/β-catenin signaling pathway

Stem Cell Res Ther. 2022 Apr 12;13(1):162. doi: 10.1186/s13287-022-02836-w.

Abstract

Background: Mitofusin-2 (MFN2) is a kind of GTPase that participates in the regulation of mitochondrial fusion, which is related to a variety of physiological and pathological processes, including energy metabolism, cell differentiation, and embryonic development. However, it remains unclear whether MFN2 is involved in the metabolism and osteogenic differentiation of mesenchymal stem cells (MSCs).

Methods: MFN2 knockdown (MFN2-KD) and MFN2-overexpressing (MFN2-OE) induced pluripotent stem cell-derived mesenchymal stem cells (iPSC-MSCs) were constructed by lentivirus. The commercial kits were utilized to detect the glycolysis and oxidative phosphorylation (OXPHOS) rate. Flow cytometry, Western blot, quantitative real-time polymerase chain reaction (qRT-PCR), RNA-seq, immunofluorescence, and immunoprecipitation were employed for phenotype and molecular mechanism assessment.

Results: We demonstrated that MFN2 and Wnt/β-catenin signaling pathway regulated glycolysis of iPSC-MSCs. The lack of MFN2 promoted the osteogenic differentiation of iPSC-MSCs, and aerobic glycolysis in the presence of sufficient oxygen, which increased glucose consumption and lactic acid production, as well as the glycolytic enzyme activity and gene expression. Inhibiting the Wnt/β-catenin signaling pathway normalized the enhanced glycolytic rate and osteogenic differentiation of MFN2-KD iPSC-MSCs. MFN2-OE iPSC-MSCs displayed the opposite phenotype.

Conclusions: Downregulating MFN2 promotes osteogenic differentiation of iPSC-MSCs through aerobic glycolysis mediated by the Wnt/β-catenin signaling pathway. Our research reveals the new function of MFN2 in regulating the osteogenic differentiation and energy metabolism of MSCs, which will provide a new therapeutic target and theoretical basis for alveolar bone repair and periodontal regenerative treatment.

Keywords: Aerobic glycolysis; Induced pluripotent stem cells; Mesenchymal stem cells; Mitofusin-2; Osteogenic differentiation; Wnt/β-catenin signaling pathway.

MeSH terms

  • Cell Differentiation / genetics
  • Cells, Cultured
  • Female
  • GTP Phosphohydrolases* / genetics
  • GTP Phosphohydrolases* / metabolism
  • Glycolysis / genetics
  • Humans
  • Induced Pluripotent Stem Cells* / metabolism
  • Mesenchymal Stem Cells* / metabolism
  • Mitochondrial Proteins* / genetics
  • Mitochondrial Proteins* / metabolism
  • Osteogenesis
  • Pregnancy
  • Wnt Signaling Pathway / genetics
  • beta Catenin / metabolism

Substances

  • Mitochondrial Proteins
  • beta Catenin
  • GTP Phosphohydrolases
  • MFN2 protein, human