SNPs in microRNA Seed Region and Impact of miR-375 in Concurrent Regulation of Multiple Lipid Accumulation-related Genes

Bovine intramuscular fat (IMF), commonly referred to as marbling, is regulated by lipid metabolism, which includes adipogenesis, lipogenesis, glycerolipid synthesis, and lipolysis. In recent years, breeding researchers have identified single nucleotide polymorphisms (SNPs) as useful marker-assisted selection tools for improving marbling scores in national breeding programs. These included causal SNPs that induce phenotypic variation. MicroRNAs (miRNAs) are small highly conserved non-coding RNA molecules that bind to multiple non-coding regions. They are involved in post-transcriptional regulation. Multiple miRNAs may regulate a given target. Previously, three SNPs in the GPAM 3' UTR and four miRNAs were identified through in silico assays. This study aimed to verify the binding ability of the four miRNAs to the 3' UTR of the GPAM gene and identify their multifunctional role in adipocytes. We verified that the four miRNAs bound to the GPAM 3'UTR and identified that the miR-375 sequence is highly conserved. Furthermore, we found that miR-375 upregulated the GPAM gene and other lipid metabolism-related genes and promoted lipid droplet accumulation in 3T3-L1 cells. In conclusion, these results suggest that miR-375 is a multifunctional regulator of multiple lipid metabolism-related genes and may aid in obesity research as a biomarker.