Overexpression of miR-133a-3p inhibits fibrosis and proliferation of keloid fibroblasts by regulating IRF5 to inhibit the TGF-β/Smad2 pathway.

•We first researched and confirmed that miR-133a-3p can prevent the development of keloids.•MiR-133a-3p can promote keloid fibroblast (KFs) apoptosis, reduce KFs proliferation and collagen deposition in cells.•MiR-133a-3p inhibits fibrosis by down-regulating the expression of TGFBR1 and phosphorylated-Smad2.•IRF5 is a target gene of miR-133a-3p, which can be negatively regulated by miR-133a-3p.