Abstract

Simple SummaryThe quality of wool is directly related to the development of hair follicles. The effect of hair follicles on hair growth is related to the processes of proliferation, differentiation and apoptosis of hair follicle stem cells (HFSCs). Therefore, research on HFSCs in agricultural animals is rapidly gaining attention. The microRNA miR-27a has been shown to be involved in several diseases, such as lung cancer, ischemic stroke, neurofibromatosis and acute myocardial infarction, but the role of miR-27a in hair follicle development has not been studied. Here, we revealed that miR-27a is involved in the proliferation and apoptosis of HFSCs through its inhibition of the AKT/MTOR signaling pathway by targetingPIK3R3. We identified an miR-27a/PIK3R3regulatory network with potential implications for hair follicle development and wool quality.AbstractMicro RNAs are regulatory factors in tissue development, organ formation, cell growth, apoptosis and other biological processes. In particular, several miRNAs are related to the development of hair follicles. Here, we investigated the effect of the targeting ofPIK3R3by miR-27a on the AKT/MTOR pathway and on the proliferation and apoptosis of hair follicle stem cells (HFSCs) in sheep. Knockdown of the expression ofPIK3R3was found to significantly inhibit the proliferation and promote the apoptosis of HFSCs. Similarly, a miR-27a mimic significantly inhibited the proliferation and promoted the apoptosis of HFSCs. The miR-27a mimic was also shown to significantly inhibit the expression ofPIK3R3, AKT, and MTOR and the phosphorylation of AKT and MTOR, while a miR-27a inhibitor increased the expression of these genes. The presence of an miR-27a binding site in the 3′ UTR ofPIK3R3was identified by a bioinformatics analysis, and the interaction was verified with a dual-luciferase reporter assay. The expression ofPIK3R3mRNA and protein was negatively correlated with the presence of miR-27a, which suggests that this interaction