食品科学 ›› 2020, Vol. 41 ›› Issue (3): 111-119.doi: 10.7506/spkx1002-6630-20181101-010

• 营养卫生 • 上一篇    下一篇

蛋氨酸限制对高脂饮食诱导的肥胖小鼠胰岛功能损伤的改善作用

罗婷玉,杨玉辉,许云聪,高秋丽,施用晖,吴国卿,乐国伟   

  1. (1.江南大学 食品科学与技术国家重点实验室,江苏 无锡 214122;2.江南大学食品学院,江苏 无锡 214122)
  • 出版日期:2020-02-15 发布日期:2020-02-26
  • 基金资助:
    国家自然科学基金面上项目(31571841);江南大学食品科学与技术国家重点实验室基金项目(SKLF-ZZB-201609); “十二五”国家科技支撑计划项目(2012BAD33B05)

Effect of Dietary Methionine Restriction on Islet Function Injury in Obese Mice Induced by High-Fat Diet

LUO Tingyu, YANG Yuhui, XU Yuncong, GAO Qiuli, SHI Yonghui, WU Guoqing, LE Guowei   

  1. (1. State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; 2. School of Food Science and Technology, Jiangnan University, Wuxi 214122, China)
  • Online:2020-02-15 Published:2020-02-26

摘要: 目的:研究饮食蛋氨酸限制(methionine restriction,MR)对高脂饮食诱导的肥胖小鼠胰腺损伤的缓解作用。方法:将210 只雄性C57BL/6J小鼠随机分为对照组(CON,0.86%(质量分数,下同)蛋氨酸+4%脂肪)30 只和高脂饮食组(HF,0.86%蛋氨酸+20%脂肪)180 只。10 周后,120 只成功诱导肥胖模型的小鼠随机分为HF组、高脂饮食+蛋氨酸限制组(HF+MR,0.17%蛋氨酸+20%脂肪)、恢复正常饮食组(C*,0.86%蛋氨酸+4%脂肪)、恢复正常饮食+蛋氨酸限制组(C*+MR,0.17%蛋氨酸+4%脂肪)。干预第24周时测定糖耐量,分别在8、16、24 周后处死小鼠,测定空腹血糖水平、胰岛素水平、血浆及胰腺H2S水平、血浆及胰腺氧化还原状态相关指标;实时荧光定量聚合酶链式反应测定胰腺胰岛素分泌相关基因以及内质网应激相关基因表达量。结果:饮食蛋氨酸限制显著降低了小鼠体质量,增加了食物摄入和能量摄入(P<0.05);显著降低了空腹血糖水平、空腹胰岛素水平、糖耐量和胰岛素抵抗指数(P<0.05);显著增加了血浆和胰腺H2S水平,改善了血浆和胰腺的氧化还原状态(P<0.05);显著上调了胱硫醚-γ-裂解酶、胱硫醚-β-合成酶、肌腱膜纤维肉瘤肿瘤基因同系物A、十二指肠同源框因子-1和B细胞淋巴瘤基因2(B-cell lymphoma 2,Bcl-2)的表达(P<0.05),显著下调了Bcl-2同源促凋亡基因、转录因子X盒结合蛋白-1、C/EBP同源蛋白、肌醇需求激酶1α的表达(P<0.05);且以上指标在HF+MR组和C*+MR组小鼠中表现出相似的变化趋势。结论:饮食蛋氨酸限制可能是通过改善高脂饮食诱导肥胖小鼠胰腺组织内质网应激和氧化还原状态,进而起到保护胰腺和促进胰岛素分泌的作用。

关键词: 蛋氨酸限制, 胰腺, 肥胖, 胰岛素抵抗, 内质网应激

Abstract: Purpose: To evaluate the protective effect of dietary methionine restriction (MR) on the pancreas of obese mice induced by high-fat diet. Methods: Totally 210 male C57BL/6J mice were divided into a control group (CON: 0.86% methionine + 4% fat; n = 30) and a high-fat diet group (HF: 0.86% methionine + 20% fat; n = 180). Obesity was successfully induced in 120 of the HF diet fed mice, and the obese mice were further randomly divided into an HF group, an HF + MR group (0.17% methionine + 20% fat), a control diet group (C*: 0.86% methionine + 4% fat) and a C* + MR group ( 0.17% methionine + 4% fat). A subset of animals in each of the four groups were euthanized at 8, 16 and 24 weeks. Glucose tolerance was determined at 24 weeks. Fasting blood glucose and plasma insulin levels, hydrogen sulfide (H2S) levels and redox indicators in plasma and pancreas were investigated. Quantitative real-time polymerase chain reaction (PCR) was used to determine the expression of genes related to insulin secretion and endoplasmic reticulum stress. Results: MR significantly reduced body mass and increased feed and energy intakes in mice (P < 0.05); decreased fasting blood glucose and plasma insulin levels, glucose tolerance and insulin resistance index (P < 0.05); increased H2S levels in plasma and pancreas and improved redox status (P < 0.05); up-regulated the mRNA expression of cystathionine-caseo-lyase (CSE), cystathie-base-synthase (CBS), v-maf musculoaponeurotic fibrosarcoma oncogene homologue (MafA), pancreatic duodenal homeobox-1 (Pdx-1) and B-cell lymphoma 2 (Bcl-2), and down-regulated the mRNA expression of Bcl-2 associated protein X (Bax), X-box binding protein-1 (Xbp-1), C/EBP homologous protein (CHOP), and inositol requiring enzyme 1α (IRE1α) (P < 0.05). Interestingly, the HF + MR and C* + MR groups showed similar trends in all the above indicators. Conclusion: MR can protect the pancreas and promote insulin secretion by improving endoplasmic reticulum stress and redox status in pancreatic tissue of obese mice.

Key words: methionine restriction, pancreas, obesity, insulin resistance, endoplasmic reticulum stress

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