biostudies-literatureJiang SBLiaoning Province Natural Science FundNational Natural Science Fund10027-10041https://www.ebi.ac.uk/biostudies/studies/S-EPMC7520305biostudies-literatureUnknown24(17)Both SIRT1 and UVA radiation are involved in cellular damage processes such as apoptosis, senescence and ageing. MicroRNAs (miRNAs) have been reported to be closely related to UV radiation, as well as to SIRT1. In this study, we investigated the connections among SIRT1, UVA and miRNA in human skin primary fibroblasts. Our results showed that UVA altered the protein level of SIRT1 in a time point-dependent manner. Using miRNA microarray, bioinformatics analysis, we found that knocking down SIRT1 could cause up-regulation of miR-27a-5p and the latter could down-regulate SMAD2, and these results were verified by qRT-PCR or Western blot. Furthermore, UVA radiation (5 J/cm² ), knocking down SIRT1 or overexpression of miR-27a-5p led to increased expression of MMP1, and decreased expreJournal of cellular and molecular medicineUVA influenced the SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in human skin primary fibroblasts.PMC7520305819729402019-ZD-0763Lu YSChen HDGao XHLi LMJiang SBLiu TWang HXWu YfalseUVA influenced the SIRT1-miR-27a-5p-SMAD2-MMP1/COL1/BCL2 axis in human skin primary fibroblasts.Both SIRT1 and UVA radiation are involved in cellular damage processes such as apoptosis, senescence and ageing. MicroRNAs (miRNAs) have been reported to be closely related to UV radiation, as well as to SIRT1. In this study, we investigated the connections among SIRT1, UVA and miRNA in human skin primary fibroblasts. Our results showed that UVA altered the protein level of SIRT1 in a time point-dependent manner. Using miRNA microarray, bioinformatics analysis, we found that knocking down SIRT1 could cause up-regulation of miR-27a-5p and the latter could down-regulate SMAD2, and these results were verified by qRT-PCR or Western blot. Furthermore, UVA radiation (5 J/cm² ), knocking down SIRT1 or overexpression of miR-27a-5p led to increased expression of MMP1, and decreased expre2020-01-01T00:00:00Z2020 Sep2026-05-03T07:14:11.055Z2020-10-08T07:14:55ZS-EPMC75203053279021010.1111/jcmm.15610