The Molecular Mechanism by Which miR-211-5p Regulates the Proliferation and Differentiation of Preadipocytes in Meat Rabbits by Targeting TPK1.

miR-211-5p exhibits dysregulated expression in various malignant tumors and has been implicated in the regulation of tumor cell proliferation, apoptosis, inflammation, and neurogenic processes. Previous studies have demonstrated that miR-211 negatively regulates ELOVL6, suggesting its involvement in lipid metabolism and lipogenesis within bovine adipose tissue. Our prior transcriptomic analysis revealed upregulated miR-211-5p expression in rabbits fed a high-fat diet, indicating its potential role in lipid metabolism regulation. However, the precise functions of miR-211-5p in lipid deposition and lipogenesis in rabbit preadipocytes remain unclear. To address this knowledge gap, this study utilized rabbit preadipocytes as experimental models to investigate the molecular mechanisms by which miR-211-5p regulates preadipocyte proliferation and differentiation. The findings aim to provide a theoretical basis for improving rabbit meat quality. The main findings of this study are summarized as follows: (1) The EdU proliferation assay, RT-qPCR detection, and CCK-8 cell viability assay revealed that overexpression of miR-211-5p inhibits the proliferation of rabbit preadipocytes, while inhibition of miR-211-5p expression promotes the proliferation of preadipocytes. (2) The precursor adipocytes were transfected and induced to differentiate. RT-qPCR, western blot (WB), and Oil Red O staining assays showed that overexpression of miR-211-5p promotes the maturation and differentiation of precursor adipocytes in meat rabbits, while inhibition of miR-211-5p expression inhibits the maturation and differentiation of precursor adipocytes in rabbits. (3) Through transcriptome sequencing, a total of 147 differentially expressed genes were identified. Among them, TPK1 is the target gene of miR-211-5p and is also the newly identified important gene involved in lipid synthesis. (4) After silencing the target gene TPK1, a series of experiments, including RT-qPCR, WB, Oil Red O staining, and CCK-8 cell viability assay, were conducted. The results showed that interfering with the expression of the TPK1 gene can inhibit the proliferation of rabbit preadipocytes and promote their differentiation. (5) After co-transfection of miR-211-5p inhibitor and si-TPK1, experiments such as EdU assay, RT-qPCR, western blot (WB), Oil Red O staining, and CCK-8 cell viability detection were conducted. It was found that miR-211-5p inhibits the proliferation and promotes the differentiation of rabbit preadipocytes by targeting TPK1.