Effect of icariin on the H2O2-induced proliferation of mouse airway smooth muscle cells through miR-138-5p regulating SIRT1/AMPK/PGC-1α axis

Icariin exerts antioxidative and anti-inflammatory effects and is used in the treatment of bronchial asthma. However, the specific modes of action are uncertain. In this study, we investigated whether icariin could modulate the silencing information regulator 2-related enzyme 1 (SIRT1)/adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor gamma co-activator 1 alpha (PGC-1 alpha) axis by regulating miR-138-5p during H2O2-induced proliferation of mouse airway smooth muscle cells (ASMCs). Primary BALB/c mouse ASMCs were cultured using the tissue block adherence method and were induced with hydrogen peroxide (H2O2; 200 mu mol/L) to establish a bronchial asthma ASMC proliferation model. With the aid of Western Blot and quantitative real-time polymerase chain reaction (qRT-PCR) in H2O2-induced ASMCs, the expression of miR-138-5p, SIRT1, AMPK, PGC-1 alpha, alpha-smooth muscle actin (alpha-SMA), transforming growth factor-beta 1 (TGF-beta 1), collagen I, and collagen III protein and mRNA were investigated. The proliferation rate and activities of superoxide dismutase1 (SOD1), reduced glutathione (GSH), malonaldehyde (MDA), and reactive oxygen species (ROS) in ASMCs were determined. The results suggest Compared with the H2O2-induced group, icariin inhibited the miR-138-5p expression; enhanced SIRT1, p-AMPK, and PGC-1 alpha expression; attenuated MDA activity and ROS level; lowered TGF-beta 1, collagen I, and collagen III expression levels; and decreased the proliferation of ASMCs induced by H2O2. The dual-luciferase reporter gene assay results showed that SIRT1 is a regulatory target of miR-138-5p.The results suggest that Icariin could improve the H2O2-induced proliferation of ASMCs. The mechanism may be related to the increase of activation of SIRT1/AMPK/PGC-1 alpha axis by suppressing the expression of miR-138-5p. Thus, SIRT1 is the regulatory target of miR-138-5p.