Stabilization of HIF-1α alleviates osteoarthritis via enhancing mitophagy

Cell Death Dis. 2020 Jun 25;11(6):481. doi: 10.1038/s41419-020-2680-0.

Abstract

Mitochondrial dysfunction leads to osteoarthritis (OA) and disc degeneration. Hypoxia inducible factor-1α (HIF-1α) mediated mitophagy has a protective role in several diseases. However, the underlying mechanism of HIF-1α mediated mitophagy in OA remains largely unknown. This current study was performed to determine the effect of HIF-1α mediated mitophagy on OA. Therefore, X-ray and tissue staining including HE staining, safranin O-fast green (S-O) and Alcian Blue were used to assess imageology and histomorphology differences of mouse knee joint. Transcriptional analysis was used to find the possible targets in osteoarthritis. Western blot analysis, RT-qPCR and immunofluorescence staining were used to detect the changes in gene and protein levels in the vitro experiment. The expression of HIF-1α was increased in human and mouse OA cartilage. HIF-1α knockdown by siRNA further impair the hypoxia-induced mitochondrial dysfunction; In contrast, HIF-1α mediated protective role was reinforced by prolylhydroxylase (PHD) inhibitor dimethyloxalylglycine (DMOG). In addition, HIF-1α stabilization could alleviate apoptosis and senescence via mitophagy in chondrocytes under hypoxia condition, which could also ameliorate surgery-induced cartilage degradation in mice OA model. In conclusion, HIF-1α mediated mitophagy could alleviate OA, which may serve as a promising strategy for OA treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Dicarboxylic / pharmacology
  • Animals
  • Apoptosis / drug effects
  • Autophagy / drug effects
  • Cartilage, Articular / metabolism
  • Cartilage, Articular / pathology
  • Cell Hypoxia / drug effects
  • Cell Hypoxia / genetics
  • Cellular Senescence / drug effects
  • Cellular Senescence / genetics
  • Chondrocytes / drug effects
  • Chondrocytes / metabolism
  • Chondrocytes / pathology
  • Cytoprotection / drug effects
  • Disease Models, Animal
  • Extracellular Matrix / genetics
  • Extracellular Matrix / metabolism
  • Female
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Male
  • Meniscus / pathology
  • Mice, Inbred C57BL
  • Middle Aged
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Mitophagy* / drug effects
  • Mitophagy* / genetics
  • Osteoarthritis / metabolism*
  • Osteoarthritis / pathology*
  • Protein Stability / drug effects
  • Reactive Oxygen Species / metabolism

Substances

  • Amino Acids, Dicarboxylic
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Reactive Oxygen Species
  • oxalylglycine