The effect of Q-switched 1064-nm dymium-doped yttrium aluminum garnet laser on the skin barrier and collagen synthesis through miR-24-3p.

Due to the increase of the world's population aging, how to restore youthfulness to the skin has attracted much attention. It is well known that collagen synthesis and changes in skin barrier play an important role in the process of skin aging. However, whether Q-switched 1064-nm Nd:YAG laser (1064-QSNYL) determines the involvement of miRNAs in skin collagen synthesis and skin barrier changes remains to be elucidated. Upstream miRNAs of p38 molecular pathway have been predicted by bioinformatic database and the relationship between miRNAs and p38 verified by dual-luciferase reporter gene and Western blotting. RT-qPCR analysis detected the expression of miR-24-3p and mRNA for collagen and skin barrier-related molecules, such as keratin 10 (K10), filaggrin, and Aquaporin 4 (APQ4), in mice back skin and in the keratinocyte cell line HaCaT. Western blotting and immunofluorescence (IF) have been used to detect collagen expression and to localize, as well as quantify K10, filaggrin, and APQ4, respectively. In this study, we show that p38 is the main target gene of miRNA-24-3p, and laser irradiation at 1.5 J/cm2 inhibits miR-24-3p expression. Irradiation treatment upregulates the moisture, elasticity, hydroxyproline, and superoxide dismutase content of mice skin, as well as inhibits trans-epidermal water loss. Irradiation also increases collagen, K10, filaggrin, and APQ4 in both mice skin and HaCaT cells. Interestingly, we found that miR-24-3p overexpression inhibits the effect of irradiation on collagen synthesis and skin barrier. We show for the first time that 1064-QSNYL promotes collagen synthesis and protective effects on skin barrier by downregulating miR-24-3p.

The effect of Q-switched 1064-nm Nd: YAG laser on skin barrier and collagen synthesis via miR-663a to regulate TGFß1/smad3/p38MAPK pathway.

BACKGROUND: Our previous research found that Q-switched 1064-nm Nd: YAG laser (1064-QSNYL) induces skin collagen synthesis by activating TGFß1/Smad3/p38MAPKs pathway. Moreover, a lot of studies shown that MicroRNAs (miRNAs) contribute to regulate collagen synthesis and skin barrier. Therefore, we intend to explore the mechanism of 1064-QSNYL on collagen synthesis and skin barrier through miRNAs. METHODS: We predicted the upstream miRNAs of TGFß1 by bioinformatics databases, and verified them through dual-luciferase reporter genes and Western blotting. The expression of collagen, skin barrier-related protein K10 and filaggrin, TIMP-1, and MMP-2 were detected by RT-qPCR and Western blotting, respectively. Moreover, we detected moisture content, elasticity value, TEWL value, SOD vitality, and hydroxyproline content to evaluate skin barrier of mice. H&E staining to observe the change of dermis thickness and inflammation and infiltration of mice skin. RESULTS: The results shown that TGFß1 was target gene of miR-663a. Moreover, we found that 1064-QSNYL activated TGFß1/smad3/p38MAPK pathway by down-regulating the expression of miR-663a in HaCaT, HDF cells, and mice, thereby promoting expression of Collagen I, Collagen IV, TIMP-1, K10, and filaggrin and inhibiting MMP-2. Furthermore, 1064-QSNYL contributed to moisture content, elasticity, SOD vitality, and hydroxyproline content via miR-663a to activate TGFß1/smad3/p38MAPK pathway. CONCLUSIONS: In summary, this study found for the first time that 1064-QSNYL contributed to collagen synthesis and skin repair via miR-663a to regulate TGFß1/smad3/p38MAPK pathway, thereby achieving skin rejuvenation.