Research Status of HIF-1α at Cartilage Level

Abstract

Regulation of hypoxic cell survival and function requires adaptation to hypoxia, which is primarily mediated by hypoxia-inducible factor-1α(HIF-1α). Cartilage and chondrocytes are exposed to a physiological hypoxic environment and studies have revealed that HIF-1α primarily involves in chondrocyte survival, cartilage metabolism, cartilage osteogenesis and maintenance of chondrocyte homeostasis as well as cartilage disease. HIF-1α is a cellular oxygen receptor that detects changes in cellular oxygen levels in an acute manner. HIF-1α can regenerate chondrocytes among patients with osteoarthritis. Moreover, the fibrous ring and nucleus pulposus in the intervertebral disc can be renovated by HIF-1α. In this paper, activation of HIF-1α through mechanical factors and metal ions is discussed. Its ability of boosting oxygen levels in hypoxic surroundings and decreasing them in enriched conditions is reviewed, which is carried out via some downstream genes. In addition, participation of HIF-1α in chondrocyte survival, cartilage metabolism, cartilage osteogenesis and maintenance of chondrocyte homeostasis as well as cartilage disease is introduced.