Q-Switched 1064nm Nd:YAG Laser Rejuvenates Photoaging Skin of Rats by Downregulating miR-196b-5p

Background: Q-switched 1064nm Nd:YAG laser (1064-QSNYL) is efficient in rejuvenating photoaging skin, and microRNAs (miRNAs) participate in this process. Objective: In this study, we aimed to explore the effects of 1064-QSNYL on miR-196b-5p, TGF-beta receptor II (TGFBR2), and SMAD7 in the photoaging skin of rats. Methods: The relationship between miR-196b-5p and TGFBR2 in HaCaT cells was detected by real-time PCR and western blotting. A skin photoaging model was established in Wistar rats using ultraviolet (UV) radiation (UVR). Dermoscopy, hematoxylin-eosin (HE) staining, Sirius red staining, and hydroxyproline content were used to observe the effect of UVR on rat skin. The 1064-QSNYL was used for skin rejuvenation. The expression of COL3A1, TGFB1, TGFBR2, SMAD2, SMAD3, and SMAD7 was detected by real-time PCR and/or western blotting. Results: TGFBR2 was a specific target of miR-196b-5p in the skin. In HaCaT cells and the photoaging skin of rats, 1064-QSNYL treatment upregulated COL3A1 and TGFBR2 and downregulated SMAD7 and miR-196b-5p. Conclusions: We showed for the first time that 1064-QSNYL treatment rejuvenates photoaging rat skin by regulating TGFBR2 and SMAD7. Downregulation of miR-196b-5p assists in this process by targeting and upregulating TGFBR2.