Perilipin1对酮病奶牛脂肪组织脂稳态和炎性通路的调节机制

Adipose tissue is not only the main organization for storing energy, but also an important inflammatory cytokines secretion organ. Ketotic dairy cows displayed disordered lipid metabolism in adipose tissue and elevated inflammatory levels. The study found that the disorders of lipid metabolism is closely related to the secretion of inflammatory cytokines in adipocytes. Perilipin1 (Plin1) is an important molecule that maintains lipid homeostasis. Therefore, we hypothesize that Plin1 could regulate the lipid metabolism and the secretion of inflammatory cytokines mediated by NLRP3 inflammasome in adipose tissue of ketotic dairy cows. In vivo, ketotic dairy cows were used as animal model. In vitro, the bovine adipocytes were cultured and treated with LPS, and transfected with Plin1 overexpression adenovirus and Plin1, ATF6, PERK and IRE-1α silencing adenovirus, respectively. The key molecules in the lipid metabolism, endoplasmic reticulum stress and inflammatory pathway were detected to investigate the effect of Plin1 on the lipid metabolism, endoplasmic reticulum stress and inflammatory pathway, and to lay groundwork for the prevention of negative energy balance diseases in perinatal dairy cows through controlling fat mobilization.

脂肪组织既是储存能量的主要组织，又是重要的炎性因子分泌器官。酮病奶牛存在脂肪组织脂代谢紊乱和炎性水平升高。研究发现脂肪组织的脂代谢紊乱与脂肪细胞炎性因子的分泌密切相关。Perilipin1（Plin1）是维持脂肪细胞脂稳态的重要分子。据此，本项目提出Plin1可调节酮病奶牛脂肪组织脂代谢及NLRP3炎性小体介导的炎性因子分泌的科学假设。通过酮病奶牛体内实验，及体外培养奶牛脂肪细胞添加LPS实验，并分别转染过表达Plin1的腺病毒及沉默Plin1、ATF6、PERK和IRE-1α的腺病毒，检测脂代谢酶、内质网应激和炎性信号通路关键分子变化，明确Plin1对奶牛脂肪细胞脂代谢、内质网应激和炎性信号通路的影响，可从缓解脂肪动员的角度预防奶牛围产期能量负平衡性疾病提供理论依据。

脂肪组织既是储存能量的主要组织，又是重要的炎性因子分泌器官。酮病奶牛存在脂肪组织脂代谢紊乱和炎性水平升高，并且有研究发现脂肪组织的脂代谢紊乱与脂肪细胞炎性因子的分泌密切相关。Perilipin1（PLIN1）是维持脂肪细胞脂稳态的重要分子。然而，PLIN1对酮病奶牛脂肪组织脂代谢和炎性因子的关键调节作用并不清楚。因此，本项目通过酮病奶牛体内实验，以及体外培养奶牛原代脂肪细胞添加LPS实验，并分别转染过表达PLIN1的腺病毒及沉默PLIN1的腺病毒，检测脂代谢和炎性信号通路的关键分子变化，明确PLIN1对奶牛脂肪细胞脂代谢和炎性信号通路的影响，从缓解脂肪动员的角度预防奶牛围产期能量负平衡性疾病提供理论依据。.结论：（1）过表达PLIN1可以激活SREBP-1c并促进其下游脂合成相关酶ACC、FAS、SCD等的表达，同时抑制PPARγ及HSL和ATGL等脂解酶的表达，进而起到促进TG在脂肪细胞内的积累。沉默PLIN时，脂合成代谢受到抑制，而脂解途径关键酶ATGL、HSL表达得到增强，进而造成脂肪细胞内脂解加强，TG大量分解。（2）PLIN1沉默时，NF-κB炎症信号通路被激活，其关键分子p65和IκB的磷酸化水平增强，进而促进其下游的炎性因子IL-1β、IL-6和TNF-α等的表达，最终诱使炎性反应的发生。过表达 PLIN1时可以通过阻止NF-κB炎症信号通路被激活进而逆转脂肪细胞炎性反应的发生。