Hypoxia and HIF-1α Regulate Collagen Production in Keloids.

Keloids are reactive or spontaneous fibroproliferative dermal tumors characterized by the exaggerated and uncontrolled accumulation of extracellular collagen. Current approaches to mitigate keloidogenesis are largely procedural in nature. However, a better understanding of its biological drivers may lead to novel targeted treatments for keloids. Through whole-genome expression analysis, we found that a HIF-1α transcriptional footprint is preferentially upregulated (activation score=2.024; p=1.05E-19) in keloid fibroblasts (KFs) compared to normal dermal fibroblasts (NFs). We verified that HIF-1α protein is more strongly expressed in keloid specimens compared to normal skin (p=0.035) and that hypoxia (1% O₂) leads to increased collagen, especially in the extracellular compartment. Collagen levels were uniformly reduced by selective HIF-1α inhibitor CAY10585. Our results indicate that collagen secretion may be intimately linked to a hypoxic microenvironment within keloid tumors and that HIF-1α blockade could be a novel avenue of treatment for these tumors.