PLIN1对奶牛脂肪细胞脂代谢及炎性细胞因子合成的影响

发布时间：2018-03-22 05:13

本文选题：能量负平衡　切入点：脂肪细胞　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：围产期是奶牛酮病和脂肪肝等能量代谢障碍性疾病的高发期,由于奶牛干物质摄入减少而能量需求增加导致能量负平衡,进而引起脂肪大量动员,造成酮病、脂肪肝等能量代谢障碍性疾病。所以能量负平衡所引起的脂肪动员是奶牛围产期能量代谢障碍性疾病的重要环节。此外,脂肪组织作为机体重要的内分泌器官,分泌多种细胞因子如肿瘤坏死因子(TNFα)、白介素1β(IL-1β)和白介素6(IL-6)等,而这些细胞因子与酮病和脂肪肝等能量代谢障碍性疾病及乳房炎和子宫内膜炎等感染性疾病的发生发展密切相关。PLIN1是在脂肪细胞中大量表达的一种脂滴包被蛋白,在脂代谢过程中起着关键的作用。明确围产期能量负平衡奶牛脂肪组织的脂代谢特征,特别是脂代谢酶表达和活性的改变是缓解脂肪动员,防治围产期能量代谢障碍性疾病的关键。同时,PLIN1对脂肪细胞炎性因子的表达分泌可能也有着特别的作用。因此,本题拟通过围产期病牛在体实验和原代培养脂肪细胞过表达及沉默PLIN1体外实验,以期揭示PLIN1对脂肪组织脂代谢的调节机制以及炎性反应的发生机制,为采用缓解脂肪动员防治奶牛围产期能量负平衡性疾病奠定理论基础。体外分离培养奶牛原代脂肪细胞,转染PLIN1过表达腺病毒和沉默si RNA。结果表明PLIN1能显著上调SREBP-1c m RNA和蛋白表达并增强其下游脂肪酸合成关键酶ACC、FAS、SCD以及DGAT1和DGAT2的表达,同时下调PPARγm RNA和蛋白表达,且抑制脂肪分解关键酶HSL和ATGL的表达,最终导致脂肪细胞中脂质的积累和脂滴的增大;沉默PLIN1能显著下调SREBP-1c m RNA和蛋白表达并抑制其下游脂肪酸合成关键酶ACC、FAS、SCD以及DGAT1和DGAT2的表达,同时上调PPARγm RNA和蛋白表达,且促进脂肪分解关键酶HSL和ATGL的表达,最终导致脂肪细胞中脂质的消耗和脂滴的减少。体外分离培养奶牛原代脂肪细胞,转染PLIN1过表达腺病毒和沉默si RNA并添加LPS刺激。结果表明,过表达PLIN1可以抑制NF-κB炎症信号通路的激活,使TNFα、IL-1β和IL-6等炎性因子的表达量下降,起到抗炎作用;沉默PLIN1后,NF-κB炎症信号通路的激活增强,TNFα、IL-1β和IL-6等炎性因子的表达量显著增加,促进炎症反应的发生及发展。以上体外实验结果表明,PLIN1促进TG在脂肪细胞的积累和脂滴的增多增大,同时可以抑制由NF-κB炎症信号通路引起的炎症反应。
[Abstract]:Perinatal period is the period of high incidence of energy metabolic disorders such as ketosis and fatty liver in dairy cows. The decrease of dry matter intake and the increase of energy demand in dairy cows lead to negative energy balance, which leads to fat mobilization and ketosis. Fatty liver and other disorders of energy metabolism. Therefore, fat mobilization caused by negative energy balance is an important part of energy metabolic disorders in dairy cows during perinatal period. In addition, adipose tissue is an important endocrine organ of the body. Many cytokines, such as tumor necrosis factor TNF- 伪, interleukin-1 尾 interleukin-1 尾 (IL-1 尾) and interleukin-6 (IL-6), are secreted. These cytokines are closely related to the development of energy metabolic disorders such as ketosis and fatty liver, as well as the occurrence and development of infectious diseases such as mastitis and endometritis. PLIN1 is a lipid coated protein that is widely expressed in adipocytes. It is important to understand the characteristics of lipid metabolism in adipose tissue of cow during perinatal negative energy balance, especially the changes in the expression and activity of lipid metabolism enzymes to alleviate fat mobilization. The key to prevent and cure perinatal disorders of energy metabolism is that PLIN1 may also play a special role in the expression and secretion of inflammatory factors in adipocytes. In order to reveal the mechanism of PLIN1 regulating lipid metabolism and inflammatory response of adipose tissue, the in vivo experiment and primary cultured adipocyte overexpression and silencing of PLIN1 were carried out in perinatal infected cattle in order to reveal the mechanism of regulation of PLIN1 on lipid metabolism in adipose tissue. In order to establish the theoretical foundation for the prevention and treatment of negative energy balance disease in the perinatal period, the primary adipocytes were isolated and cultured in vitro. The results showed that PLIN1 could significantly up-regulate the expression of SREBP-1c m RNA and protein and enhance the expression of key fatty acid synthase ACC-FAS-SCD, DGAT1 and DGAT2, and down-regulate the expression of PPAR 纬 m RNA and protein. Inhibiting the expression of HSL and ATGL resulted in the accumulation of lipid and the increase of lipid droplets in adipocytes. Silencing PLIN1 could significantly down-regulate the expression of SREBP-1c m RNA and protein and inhibit the expression of ACC-FAS-SCD, DGAT1 and DGAT2, and up-regulate the expression of PPAR 纬 m RNA and protein, and promote the expression of HSL and ATGL. In vitro, the primary adipocytes of dairy cattle were isolated and cultured, transfected with PLIN1 overexpression of adenovirus and silencing of si RNA, and then stimulated by LPS. Overexpression of PLIN1 could inhibit the activation of NF- 魏 B inflammatory signaling pathway, decrease the expression of inflammatory factors such as TNF 伪, IL-1 尾 and IL-6, and play an anti-inflammatory role, and after silencing PLIN1, the activation of NF- 魏 B inflammatory signaling pathway enhanced the expression of inflammatory factors such as TNF- 伪, IL-1 尾 and IL-6. The results showed that PLIN1 promoted the accumulation of TG in adipocytes and the increase of lipid droplets, and inhibited the inflammatory response induced by NF- 魏 B inflammatory signaling pathway.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.23

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