The Role of miR-326-3p in Regulating Differentiation and Thermogenesis Genes in Goat Brown Adipocytes

Background: Brown adipose tissue (BAT) is indispensable for producing heat and contributes critically to the survival of neonatal mammals. MicroRNAs (miRNAs) are small noncoding RNAs that serve as key post-transcriptional regulators, playing a crucial role in regulating BAT development and thermogenesis. However, the role of miR-326-3p in goat brown adipocytes remains largely unclear. Methods: Primary brown adipocytes were isolated from goat perirenal adipose tissue and subjected to gain and loss-of-function assays using miR-326-3p mimics and inhibitors. Lipid accumulation, thermogenic-related genes, and mitochondrial gene expression were quantified by Oil Red O staining and qRT-PCR. Target prediction and dual-luciferase reporter assays were performed to validate direct interaction between miR-326-3p and FGF11. Results: Expression profiling demonstrated that miR-326-3p is more enriched in brown adipose tissue (BAT) than in white adipose tissue (WAT), and the expression level gradually decreases with adipocyte differentiation. miR-326-3p overexpression significantly inhibited lipid droplet accumulation and the expression of genes associated with differentiation, thermogenesis, and mitochondria, including PPARγ, FABP4, UCP1, and PGC1α, whereas inhibition produced the opposite effect. Bioinformatic prediction and dual-luciferase reporter assays further identified fibroblast growth factor 11 (FGF11) as a direct target of miR-326-3p. Conclusions: These findings reveal that miR-326-3p negatively regulates the differentiation and expression of thermogenic-related genes of goat brown adipocytes, uncovering a novel miR-326-3p-FGF11 regulatory axis.