SIRT3调控奶牛卵巢颗粒细胞高酮损伤的分子机制研究

酮病是高产奶牛围产期易发性疾病，在诱发奶牛减产的同时还损伤卵巢颗粒细胞，引起产后繁殖障碍，但损伤机制不明。申请人前期研究发现，酮病主要代谢产物β-羟基丁酸可引起颗粒细胞去乙酰化酶3（SIRT3）低表达，造成线粒体功能障碍，提示SIRT3可能通过影响线粒体功能调控酮病诱导的颗粒细胞损伤。本项目针对高酮造成颗粒细胞损伤这一科学问题，重点研究：①SIRT3在酮病奶牛颗粒细胞中的表达和定位以及对线粒体功能的影响；②构建敲降和过表达SIRT3的颗粒细胞模型，探究高酮应激下SIRT3对酮体代谢、激素合成和线粒体功能的调节作用；③激活PINK1-Parkin信号通路，解析高酮应激下SIRT3对线粒体自噬和凋亡的影响，以及与PINK1-Parkin信号通路的靶向关系。初步阐明SIRT3调控奶牛卵巢卵泡颗粒细胞高酮损伤的分子机制。预期研究结果将为研究开发缓解酮病奶牛低繁殖力的分子干预新技术提供理论支撑。

Ketosis is a common metabolic disease in high-yielding dairy herds during the perinatal period. It not only reduces lactation, but also damages ovarian granulosa cells (GCs), which ultimately caused postnatal reproductive disorders. However, the mechanism of ketosis-induced injury is still unclear. The results of our previous studies showed that β-hydroxybutyric acid (BHBA), the main metabolite of ketosis, led to a low expression of SIRT3 in GCs, and the mitochondrial function was also damaged. The results suggest that SIRT3 appears to regulate ketosis-induced GCs injury by affecting mitochondrial function. The present study aims at the important scientific issue of ketosis-induced GCs injury, focusing on: (1) the expression and localization of SIRT3 in GCs and effect of SIRT3 on mitochondrial function in cows with ketosis; (2) effect of SIRT3 on ketone metabolism, hormone synthesis and mitochondrial function under ketosis stress by constructing SIRT3 knockdown and overexpression models; (3) analyzing the influence of SIRT3 on mitochondrial autophagy and apoptosis under ketosis stress upon activation of PINK1-parkin signaling pathway, as well as the targeting relationship between them. The results will preliminarily illustrate the molecular mechanism of SIRT3 in mediating high ketone body-induced damage to GCs in dairy cattle. Furthermore, the findings will provide a theoretical basis for developing new technologies to alleviate ketosis-associated low fecundity in dairy herds.