Regulation of secondary hair follicle cycle in cashmere goats by miR-877-3p targeting IGFBP5 gene

Cashmere, a highly valuable animal product derived from cashmere goats, holds significant economic importance. MiRNAs serve as crucial regulators in the developmental processes of mammalian hair follicles. Understanding the regulation of miRNAs during the hair follicle cycle is essential for enhancing cashmere quality. In this investigation, we employed high-throughput sequencing technology to analyze the expression profiles of miRNAs in the secondary hair follicles of Jiangnan cashmere goats at different stages. Through bioinformatics analysis, we identified differentially expressed miRNAs (DE miRNAs). The regulatory relationships between miRNAs and their target genes were verified using multiple techniques, including RT-qPCR, western blot, Dual-Luciferase Reporter, and CKK-8 assays. Our findings revealed the presence of 193 DE miRNAs during various stages of the hair follicle cycle in Jiangnan cashmere goats. Based on the previously obtained mRNA data, the target genes of DE miRNA were predicted, and 1,472 negative regulatory relationships between DE miRNAs and target genes were obtained. Notably, the expression of chi-miR-877-3p was down-regulated during the telogen (Tn) phase compared to the anagen (An) and catagen (Cn) phases, while the IGFBP5 gene exhibited up-regulation. Further validation experiments confirmed that overexpression of chi-miR-877-3p in dermal papilla cells suppressed IGFBP5 gene expression and facilitated cell proliferation. The results of this study provide novel insights for analyzing the hair follicle cycle. This study reports a miRNA that regulates hair follicle cycle in cashmere goats. Lay Summary Cashmere goats, known for their diverse range of animal products including delectable meat, soft sheepskin, and high-quality natural fiber, offer an excellent opportunity to explore hair regeneration as they represent a heterogenous fur mammal. MicroRNAs (miRNAs) are small non-coding RNA molecules encoded by approximately 3% of mammalian genes. Remarkably, they have the ability to regulate around 30% of protein-coding genes. Given that a single miRNA can target multiple genes, they exert control over various biological functions such as metabolism, growth, development, and immunity. In this study, we found that miR-877-3p is able to regulate the expression of insulin-like growth factor binding protein 5 (IGFBP5), a key gene involved in the development of the hair follicle cycle. Investigating the regulatory role of miRNAs in the hair follicle cycle of cashmere goats provides a novel perspective for unraveling the mechanisms underlying hair follicle growth and development in mammals.