Hypoxic regulation of ADAMTS-2 and-3 (a disintegrin and matrix metalloproteinase with thrombospondin motifs 2 and 3) procollagen N proteinases by HIF-1α in endothelial cells

ADAMTS-2 and ADAMTS-3, known as procollagen amino proteases (PNP), are primarily responsible for processing the amino ends of the fibrillar collagen precursors. ADAMTS-2 is a highly expressed gene in type I collagen-rich tissues, such as skin, bones, tendons, and aorta. ADAMTS-3 is mainly expressed in cartilage, where it colocalizes with type II procollagen and in the nervous system. Studies about ADAMTS-2 and ADAMTS-3 enzymes primarily focused on their collagen processing activity. Knowledge about the transcriptional regulations of these genes is rather limited. Here we analyzed the transcriptional regulations of ADAMTS-2 and ADAMTS-3 genes under chemically induced hypoxic conditions in endothelial cell model, HUVECs. We elucidated that hypoxia is the potent positive regulator of ADAMTS-2 and ADAMTS-3 genes. qRT-PCR and western blotting studies revealed that ADAMTS-2 and ADAMTS-3 expressions were increased at mRNA and protein levels under chemically induced hypoxic conditions in HUVECs. In addition, Transient transfection experiments of ADAMTS-2 and ADAMTS-3 promoter-reporter constructs indicated that low oxygen conditions increased ADAMTS-2 and ADAMTS-3 promoter activities. Furthermore, the DNA-protein interaction assay provided evidence of the functional binding of HIF-1 alpha on bioinformatically determined HRE regions on the ADAMTS-2 and ADAMTS-3 promoters.

Automated summary

ADAMTS-2 and ADAMTS-3 are essential enzymes involved in the processing of fibrillar collagen precursors. This study reveals that under hypoxic conditions, ADAMTS-2 and ADAMTS-3 gene transcription and protein expression are upregulated, and the binding of HIF-1α to their promoter regions is functionally significant.