应激通过FATP1影响肉鸡骨骼肌脂肪沉积的作用机制

发布时间：2018-04-22 09:09

本文选题：肉仔鸡 + 糖皮质激素　；参考：《山东农业大学》2017年硕士论文

【摘要】：FATP1作为脂肪酸转运蛋白,在机体脂肪酸转运摄取方面发挥着重要作用。本论文从"脂肪酸转运影响脂肪沉积"的角度出发,利用活体和离体试验,在核酸、蛋白、细胞、组织等水平系统研究了FATP1在糖皮质激素(DEX)调控肉鸡骨骼肌脂肪异位沉积中的作用及机制。1.FATP1在应激肉鸡骨骼肌脂肪代谢中的作用。处理组根据肉鸡体重注射DEX。结果表明,DEX处理会导致肉鸡肌肉组织FATP1的mRNA水平升高,脂肪沉积量增多,血液中VLDL和INS含量显著升高。腿肌糖皮质激素受体(GR)、脂联素受体(ADPNR)、过氧化物酶体增殖物激活受体α(PPARα)的mRNA水平也升高。由这些结果推测,DEX调控骨骼肌的FATP1促进脂肪摄取可能是通过GR-ADPNR-PPARα通路实现的。2.脂肪水平对糖皮质激素调控FATP1的影响。分别用不同脂肪水平的日粮饲喂肉鸡,35日龄时用DEX处理。试验结果表明,低脂日粮饲喂肉鸡组用DEX处理后肌肉组织TG沉积量增多,但高脂日粮饲喂肉鸡组用DEX处理后各组织脂肪沉积量无显著变化;低脂日粮饲喂肉鸡并用DEX处理后,肉鸡肌肉组织GR、ADPNR、PPARα和FATP1的mRNA水平与组织TG沉积量有相同变化趋势。但是,这种趋势在饲喂高脂日粮并用DEX处理后的肉鸡腿肌上表现不明显。由此可以推出,不同日粮处理下DEX对肌肉GR-ADPNR-PPARα-FAPT1通路基因水平的影响并不一致。3.脂肪酸类型对糖皮质激素调控FATP1的影响。利用添加了相同浓度油酸和棕榈酸的条件培养基分别培养成肌细胞,细胞分化至80%左右分别用不同浓度的DEX处理。结果表明,用饱和脂肪酸培养的细胞用DEX处理后,细胞脂肪沉积增多,而不饱和脂肪酸培养的细胞用DEX处理后细胞脂肪沉积量有所下降;检测细胞AKT蛋白的磷酸化水平,结果显示DEX处理对其无显著影响;油酸培养细胞DEX处理后检测到相关基因的mRNA水平无显著差异,而棕榈酸培养的成肌细胞用DEX处理后检测到GR、ADPNR、PPARα和FATP1的mRNA水平变化趋势与细胞中TG沉积量的变化趋势基本一致。这说明不同脂肪酸类型会影响DEX对FATP1的调控作用,进而影响细胞TG的沉积量。4.糖皮质激素通过FATP1调控成肌细胞脂肪沉积的途径。单独DEX处理成肌细胞,发现FATP1和PPARα的mRNA水平无显著变化;利用添加了相同浓度油酸和棕榈酸的条件培养基分别培养成肌细胞,细胞分化至80%左右分别利用特异性抑制剂RU486、U0126、GW6471特异性抑制GR、ERK2/MAPK和PPARα在细胞中的作用,并用DEX处理。发现油酸培养的成肌细胞用抑制剂和DEX处理后脂肪酸摄取无显著差异,棕榈酸培养的成肌细胞用抑制剂处理后脂肪酸摄取能力下降。这说明DEX会通过GR-PPARα途径或ERK2/MAPK-PPARα途径调控细胞对饱和脂肪酸的摄取。综上所述,糖皮质激素可能通过升高FATP1的mRNA水平促进细胞对脂肪酸的转运摄取,进而导致脂肪沉积。日粮不同脂肪水平会影响到糖皮质激素通过FATP1对肉鸡骨骼肌脂肪沉积的调控作用,细胞培养底物的脂肪酸类型也会影响到糖皮质激素通过FATP1对成肌细胞脂肪沉积的调控作用。糖皮质激素应激条件下,细胞倾向于通过GR-PPARα或ERK2/MAPK-PPARα通路摄取饱和脂肪酸。本研究揭示了应激导致骨骼肌脂肪异位沉积的调控靶点,阐明了日粮脂肪与糖皮质激素的相互作用。
[Abstract]:FATP1, as a fatty acid transporter, plays an important role in the transport of fatty acid in the body. From the point of view of "fatty acid transport affecting adipose deposition", this paper studies the regulation of FATP1 by Glucocorticoid (DEX) in the skeletal muscle of Broilers by living and in vitro experiments at the level of nucleic acid, protein, cell and tissue. The role of.1.FATP1 in the lipid metabolism in the skeletal muscle of broilers. The results of the treatment group by injection of DEX. according to the body weight of broiler showed that DEX treatment could lead to the increase of mRNA level in the muscle tissue of the broiler, the increase of the fat deposition, the increase of the content of VLDL and INS in the blood. The leg muscle glucocorticoid receptor (GR) and the adiponectin were affected. The mRNA level of the peroxisome proliferator activated receptor alpha (PPAR alpha) is also elevated in the body (ADPNR). From these results, it is speculated that the DEX regulation of the FATP1 of skeletal muscle may be the effect of the.2. fat level on the glucocorticoid regulated FATP1 through the GR-ADPNR-PPAR alpha pathway. The diets of broilers were fed on the diet of different fat levels, 35 DEX treatment was used at the age of age. The results showed that the amount of TG deposition in the muscle tissue was increased after DEX treatment in the low fat diet diet, but there was no significant change in the fat deposition in the tissues of the broiler group fed with DEX. The mRNA levels of GR, ADPNR, PPAR A and FATP1 in broiler muscle tissues were compared with those of low fat diet fed broilers and DEX treated with DEX. TG deposition in tissue has the same trend of change. However, this trend is not obvious on the meat chicken leg muscles treated with high fat diet and DEX treatment. Therefore, the effect of DEX on the GR-ADPNR-PPAR alpha -FAPT1 pathway gene level in different diets does not agree with the effect of.3. fatty acid type on the regulation of FATP1 in glucocorticoids. The myocytes were cultured with the condition medium added with the same concentration of oleic acid and palmitic acid. The cell differentiation to about 80% was treated with different concentrations of DEX. The results showed that after the cells cultured with saturated fatty acids were treated with DEX, the cell fat deposition was increased, and the cells cultured in unsaturated fatty acid were treated with DEX after DEX treatment. The deposition of AKT protein was decreased, and the results showed that the DEX treatment had no significant effect on it. The mRNA level of the related genes was not significantly different after DEX treatment in oleic acid culture cells, and the mRNA level of GR, ADPNR, PPAR A and FATP1 in the myoblast cultured by palmitic acid was detected by DEX. The change trend of TG deposition is basically the same. This shows that different types of fatty acids can affect the regulation of DEX on FATP1, and then influence the deposition of TG,.4. glucocorticoid, through FATP1 regulation of myoblast fat deposition. The single DEX treatment of myoblasts, found that FATP1 and PPAR alpha mRNA levels have no significant changes; use of addition to the use of addition. The condition medium with the same concentration of oleic acid and palmitic acid were cultured into myocytes, and the cells differentiated to about 80% by specific inhibitors RU486, U0126, GW6471, the role of GR, ERK2/MAPK and PPAR alpha in the cells, and DEX treatment. The fatty acid uptake of the myoblasts cultured by oleic acid and after DEX treatment was found. There is no significant difference between the palmitic acid cultured myoblasts and the decrease in fatty acid uptake by inhibitors. This suggests that DEX regulates the uptake of saturated fatty acids through the GR-PPAR alpha pathway or ERK2/MAPK-PPAR alpha pathway. To sum up, glucocorticoids may promote the uptake of fatty acids by increasing the mRNA level of FATP1. And then lead to fat deposition. Different levels of dietary fat may affect the regulation of glucocorticoid through FATP1 on the fat deposition of skeletal muscle in broilers. The type of fatty acids in cell culture substrates also affects the regulation of glucocorticoid through FATP1 on the adipose deposition of myoblasts. Under glucocorticoid stress conditions, cell tendencies This study reveals the regulatory target of stress induced adipose deposition in skeletal muscle and elucidates the interaction between dietary fat and glucocorticoid through the uptake of saturated fatty acids through the GR-PPAR alpha or ERK2/MAPK-PPAR alpha pathway.

【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S831

【参考文献】