1343 Altered metabolism of elastic fibers and collagen fibers derived from TGF-β1 mediated inflammation in atrophic acne scarring

Abstract

This study was conducted to reveal the process of atrophic acne scar formation in histological and molecular views. Thirty subjects with acne were divided into two groups; fifteen were prone to acne scar (APS) and the others were not prone to acne scar (ANS). Skin samples of acne lesions were obtained on day 1, 3 and 7 after their onset. Elastic fibers, collagen 1 and collagen 3 were significantly decreased and their recovery was delayed in APS compared to those in ANS. On the other hand, the production of neutrophil elastase, matrix metalloproteinases (MMP)-1, MMP-2 and MMP-3 was substantially increased in APS compared to that in ANS. More severe inflammation with elevated various proinflammatory cytokines including IL-1α, IL-1β, IL-6 and TNF-α was observed in APS than in ANS, implicating that excessive inflammation contributes to the aberrant ECM degradation and healing. In this process, it was found that increased TGF-β1 in APS may play a crucial role in aggravating inflammation via activating phospho-TAK1 and NF-κB p65. These results propose the detailed pathogenesis of atrophic acne scarring and ultimately provide a basis of a new therapeutic approach in atrophic acne scar.