ERK和cAMP-PKA信号通路互作在Myostatin/miR-130b/PPAR-γ轴调控梅山猪肌内脂肪沉积中的作用与机制研究

肌内脂肪(IMF)含量是影响猪肉品质的关键因素之一，然而IMF沉积被肌肉因子特异性调控的作用及机制尚不明晰。本研究继续以梅山猪肌内前体脂肪细胞为材料，以课题组前期研究发现的在肌内前体脂肪细胞成脂分化中起关键作用的MSTN/miR-130b轴为对象，深入探讨该轴介导梅山猪IMF沉积的分子机制。首先通过生物信息学分析、双荧光素酶报告基因、“过表达”和“干扰”等方法阐明MSTN/miR-130b与下游基因PPAR-γ之间的靶向关系，然后以猪IMF细胞和小鼠为模型，研究MSTN通过外泌体包裹的miR-130b调控IMF沉积的分子机制，重点围绕脂滴融合、ERK和cAMP-PKA信号通路及其“crosstalk”进行深入探讨。研究结果可明确MSTN/miR-130/PPAR-γ轴在特异性调控IMF沉积中的作用及ERK和cAMP-PKA信号通路互作介导的分子机制，从而为实现猪肉品质调控提供理论基础。

Intramuscular fat (IMF) content is one of the critical factors affecting pork quality. However, the molecular mechanism by which the IMF deposition is specifically regulated by muscle-derived factors is still unclear. In this project, we continue to use the intramuscular preadipocytes of Meishan pigs as experimental materials, and use the MSTN/miR-130b axis as the research object, which has been found to play key roles in the intramuscular preadipocytes adipogenic differentiation of Meishan pigs in our previous project, to further investigate the molecular mechanism of this axis in affecting the IMF deposition of Meishan pigs. We firstly clarify the targeting relationship between MSTN/miR-130b and its potential target gene PPAR-γ through bioinformatics software prediction, dual luciferase reporter gene assay, "gain-of-function" and "loss-of-function" methods. Then, using porcine intramuscular preadipocytes and mice as models, we further demonstrate the molecular mechanisms of MSTN in the regulation of the IMF deposition through microvesicle-packaged miR-130b, especially focus on the lipid droplet fusion and the "crosstalk" of ERK and cAMP-PKA signaling pathways. These research results can clarify the role of MSTN/miR-130/PPAR-γ axis in the specific regulation of IMF deposition and the molecular mechanism mediated by the interaction of ERK and cAMP-PKA signaling pathway, thus providing a theoretical basis for the regulation of pork quality.