TGF-β3介导的凋亡细胞清除障碍对酮病奶牛乳腺TLR4介导的局部天然免疫功能调节作用及分子机制

酮病奶牛存在严重的糖脂代谢紊乱导致乳腺组织细胞不同程度的凋亡。凋亡细胞清除障碍可导致乳腺组织天然免疫功能紊乱，TGF-β3作为调节凋亡细胞清除的重要分子，极有可能参与到酮病奶牛乳腺天然免疫功能紊乱这一病理过程。据此，我们提出酮病奶牛严重的代谢应激扰乱TGF-β3/Smads信号通路，导致凋亡的乳腺上皮细胞清除障碍，进而诱导乳腺局部天然免疫功能紊乱的科学假设。拟通过酮病奶牛体内实验，及体外培养奶牛乳腺上皮细胞分别转染过表达TGF-β3的腺病毒及沉默TGF-β3、Smad3和TLR4的腺病毒，检测凋亡细胞清除及TLR4介导的天然免疫功能变化，明确TGF-β3对奶牛乳腺上皮凋亡细胞清除功能及TLR4介导的天然免疫功能的影响，从维持乳腺局部天然免疫功能的角度，为防治酮病奶牛代谢紊乱诱发的乳腺炎性疾病提供理论依据和实验基础。

Severe metabolic disorders of glucose and lipid induce severe apoptosis in the mammary gland of ketotic dairy cows. Impaired clearance of apoptotic cells results in dysfunction of innate immune function. As an important molecule regulating the clearance of apoptotic cells, TGF-β3 is likely to be involved in the dysfunction of local innate immune function in mammary gland of ketotic dairy cows. Therefore, we hypothesize that severe metabolic stress disrupts the TGF-β3/Smads signaling pathway and leads to impaired clearance of apoptotic mammary epithelial cells, which induces local innate immune function in mammary gland of ketotic dairy cows. In vivo, ketotic dairy cows were used as animal model. In vitro, cultured bovine mammary epithelial cells were transfected with TGF-β3 overexpression adenovirus and TGF-β3, Smad3 or TLR4 silencing adenovirus. The TGF-β3-mediated clearance of apoptotic cell and TLR4-mediated innate immune function changes were detected to investigate the effect of TGF-β3 on the clearance of apoptotic cell and TLR4-mediated innate immune function and to lay groundwork for the prevention and treatment of inflammatory disease of mammary induced by metabolic disorders in ketotic cows through maintaining the local natural immune function.