The effects of the metformin on inhibition of UVA-induced expression of MMPs and COL-I in human skin fibroblasts

Abstract

This study was to investigate the effects of metformin (MF) on ultraviolet A (UVA)-induced expression of matrix metalloproteinases (MMPs) and type I collagen (COL-I) in human skin fibroblasts (HSFs). HSFs were cultured in vitro and divided into control group, UVA group, and UVA + MF group. Cell proliferation was detected by CCK-8 method, and intracellular reactive oxygen species (ROS) level was detected by flow cytometry with fluorescent probe 2′,7′-dichlorofluorescein diacetate (DCF-DA) staining. Meanwhile, real-time polymerase chain reaction (PCR) was used to examine the relative messenger RNA (mRNA) expression of aging-related genes, including MMP1, MMP3, and COL-I. Moreover, the expression of MMP1, MMP3, and COL-I proteins was further detected by western blot. Compared with the control group, the ROS content in the UVA group was increased significantly (P < 0.05), while the ROS content in the UVA + MF group was evidently lower than that in the UVA group (P < 0.05). In addition, the MMP1 and MMP3 mRNA levels were significantly elevated, while the COL-I mRNA was significantly decreased in UVA-induced HSF cells compared with the control cells. However, MF could significantly inhibit the improved MMP1 and MMP3 mRNA level and increase the COL-I mRNA level. Moreover, MF could significantly reverse the increasing MMP1 and MMP3 protein level and decreasing COL-I protein level induced by UVA. In conclusion, MF can increase the antioxidant capacity of cells and increase the synthesis of COL-I by inhibiting the level of intracellular ROS and the expression of related MMPs, thereby inhibiting the UVA-induced photoaging effect of HSF.