Hypoxia-inducible factor-2alpha is a catabolic regulator of osteoarthritic cartilage destruction.
Osteoarthritic cartilage destruction is caused by an imbalance between anabolic and catabolic factors. Here, we show that hypoxia-inducible factor-2alpha (HIF-2alpha, encoded by EPAS1) is a catabolic transcription factor in the osteoarthritic process. HIF-2alpha directly induces the expression in chondrocytes of genes encoding catabolic factors, including matrix metalloproteinases (MMP1, MMP3, MMP9, MMP12 and MMP13), aggrecanase-1 (ADAMTS4), nitric oxide synthase-2 (NOS2) and prostaglandin-endoperoxide synthase-2 (PTGS2). HIF-2alpha expression was markedly increased in human and mouse osteoarthritic cartilage, and its ectopic expression triggered articular cartilage destruction in mice and rabbits. Moreover, mice transgenic for Epas1 only in chondrocytes showed spontaneous cartilage destruction, whereas heterozygous genetic deletion of Epas1 in mice suppressed cartilage destruction caused by destabilization of the medial meniscus (DMM) or collagenase injection, with concomitant modulation of catabolic factors. Our results collectively demonstrate that HIF-2alpha causes cartilage destruction by regulating crucial catabolic genes.
Yang
Siyoung
S
Cell Dynamics Research Center, School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, Korea.
Kim
Jonghwan
J
Ryu
Je-Hwang
JH
Oh
Hwanhee
H
Chun
Churl-Hong
CH
Kim
Byoung Ju
BJ
Min
Byoung Hyun
BH
Chun
Jang-Soo
JS
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000502:physiology*; D002356:Cartilage / Q000378:metabolism* / Q000503:physiopathology; D019902:Chondrocytes / Q000378:metabolism / Q000502:physiology; D017364:Collagenases / Q000378:metabolism / Q000502:physiology; D002373:Cyclic AMP Receptor Protein / Q000235:genetics / Q000502:physiology; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D055785:Gene Knockdown Techniques; D005796:Genes / Q000235:genetics / Q000502:physiology; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D010003:Osteoarthritis / Q000378:metabolism* / Q000503:physiopathology; D011817:Rabbits; D014157:Transcription Factors / Q000502:physiology*; D000099162:Endothelial PAS Domain-Containing Protein 1
D051792:Basic Helix-Loop-Helix Proteins; D017364:Collagenases; D002373:Cyclic AMP Receptor Protein; D014157:Transcription Factors; D000099162:Endothelial PAS Domain-Containing Protein 1