MicroRNA expression analysis of human skin fibroblasts treated with high-fluence light-emitting diode-red light.

Skin fibrosis is a chronic debilitating feature of several skin diseases that lead to characteristic increases in dermal fibroblast proliferation and collagen deposition through upregulation in components of the transforming growth factor beta (TGF-B)/SMAD pathway. In contrast to ultraviolet phototherapy, high-fluence light-emitting diode-generated red light (HF-LED-RL, 633 ± 15 nm) is a safe, economic and non-invasive therapy with in vitro evidence that supports modulation of the key cellular characteristics involved in the pathogenesis of skin fibrosis. Limited data exists pertaining to the effects of HF-LED-RL on human skin fibroblast microRNA (miRNA). Herein, we explored the effects of HF-LED-RL on fibroblast miRNA levels using RNA-seq and miRNA expression analysis. Using RNA-seq analysis we found that HF-LED-RL at 320 and 640 J/cm2 increased transcription of key miRNA that are involved in skin fibrosis including miRNA-29, miRNA-196a and Let-7a, and decreased transcription of miRNA-21, miRNA-23b and miRNA-31. These microRNA findings provide insight into the molecular underpinnings of HF-LED-RL and highlight potential therapeutic targets of interest for the treatment of skin fibrosis. Additional research on the specific molecular mechanisms underlying HF-LED-RL effects on fibroblasts may provide further mechanistic insight into this therapy and may reveal additional future therapeutic targets for skin fibrosis.