ABSTRACT
BACKGROUND: Recent studies indicate that light-emitting diodes (LED) may represent a novel and effective anti-aging light source for the skin. Among many candidate molecules known to control collagens, caveolin-1 (Cav-1) is known to play an inhibitory role in cutaneous collagen metabolism. OBJECTIVE: This study aimed to evaluate the effects of LED irradiation on the expression levels of Cav-1 and procollagens (proCOLs) in human dermal fibroblasts (HDFs). METHODS: Cultured HDFs were irradiated with 630 nm LED at different doses, and the mRNA and protein expression levels of Cav-1 and proCOLs I/III were analyzed. RESULTS: In LED-irradiated HDFs, mRNA and protein levels of Cav-1 were found to be down-regulated, whereas those of proCOLs I/III were up-regulated in a dose-dependent manner. A negative correlation between Cav-1 and proCOLs was verified in Cav-1 siRNA transfected HDFs. LED was moreover found to result in up-regulation of transforming growth factor (TGF)-beta1 and its receptors (TbetaRI, TbetaRII), SMAD1, and SMAD2 mRNA levels, indicating that LED may activate the TGF-1/TbetaR/SMAD pathway in HDFs. CONCLUSION: The anti-aging effects of 630 nm LED on human skin are likely mediated by up-regulation of proCOLs I/III and inhibition of Cav-1 expression levels in HDFs.