中国组织工程研究 ›› 2024, Vol. 28 ›› Issue (28): 4469-4476.doi: 10.12307/2024.340

• 组织构建实验造模 experimental modeling in tissue construction • 上一篇    下一篇

二甲双胍预处理诱导心脏自噬减轻脓毒症小鼠的心肌损伤

田  勇1,2,周  颖1,古雍翔1,杨国辉3   

  1. 1贵州医科大学,贵州省贵阳市  550004;2铜仁市人民医院重症医学科,贵州省铜仁市  554300;3贵州医科大学附属医院,贵州省贵阳市  550004
  • 收稿日期:2023-04-18 接受日期:2023-06-01 出版日期:2024-10-08 发布日期:2023-11-27
  • 通讯作者: 杨国辉,主任医师,教授,贵州医科大学附属医院,贵州省贵阳市 550004
  • 作者简介:田勇,贵州省印江县人,土家族,贵州医科大学在读硕士,铜仁市人民医院重症医学科主治医师,主要从事重症感染、自噬的相关研究。
  • 基金资助:
    贵州医科大学国家自然科学基金培育项目(gyfynsfc-2021-54),项目负责人:杨国辉;贵州省卫生健康委科学技术基金项目(gzwjkj2020-1-026),项目负责人:杨国辉

Metformin pretreatment induces cardiac autophagy to reduce myocardial injury in septic mice

Tian Yong1, 2, Zhou Ying1, Gu Yongxiang1, Yang Guohui3   

  1. 1Guizhou Medical University, Guiyang 550004, Guizhou Province, China; 2Intensive Care Unit, Tongren City People’s Hospital, Tongren 554300, Guizhou Province, China; 3Affiliated Hospital of Guizhou Medical University, Guiyang 550004, Guizhou Province, China
  • Received:2023-04-18 Accepted:2023-06-01 Online:2024-10-08 Published:2023-11-27
  • Contact: Yang Guohui, Professor, Chief physician, Affiliated Hospital of Guizhou Medical University, Guiyang 550004, Guizhou Province, China
  • About author:Tian Yong, Master candidate, Guizhou Medical University, Guiyang 550004, Guizhou Province, China; Intensive Care Unit, Tongren City People’s Hospital, Tongren 554300, Guizhou Province, China
  • Supported by:
    Culture Program for the Affiliated Hospital of Guizhou Medical University, The National Natural Science Foundation of China, No. gyfynsfc-2021-54 (to YGH); Guizhou Provincial Health Commission Science and Technology Fund Project, No. gzwjkj2020-1-026 (to YGH)

摘要:


文题释义:

二甲双胍:一种从山羊豆中提取的胍类化合物,作为2型糖尿病的一线用药,可通过激活腺苷单磷酸激酶影响神经和内分泌系统,发挥降低血脂、减轻体质量、参与抗炎、减轻氧化应激、调控自噬等作用,从而对心血管疾病发挥保护作用。
自噬:是一种进化上保守的细胞内消化过程,细胞通过自噬将胞质中的物质运送到溶酶体中进行降解,根据降解方式将自噬分为3 种类型:巨自噬、微自噬、分子伴侣介导的自噬,文中所讲的自噬为巨自噬,适当的自噬有利于维持细胞内环境稳态及生存。


背景:脓毒症并发心肌损伤具有高死亡率的特点,二甲双胍可通过抗炎、改善氧化应激、减少细胞凋亡等多种方式对脓毒症器官功能障碍发挥保护作用,而二甲双胍诱导的自噬在脓毒症心肌损伤中是否扮演重要的角色尚不清楚。

目的:探究二甲双胍预处理对脓毒症小鼠心肌损伤的作用。
方法:雄性昆明小鼠40只,随机分为假手术组、模型组、二甲双胍组、二甲双胍+3-甲基腺嘌呤组,每组10 只,后2 组在每日固定时间予二甲双胍连续腹腔注射14 d,二甲双胍+3-甲基腺嘌呤组在建模前1 h腹腔注射自噬抑制剂3-甲基腺嘌呤;在末次注射二甲双胍后24 h,采用盲肠结扎穿孔术构建脓毒症小鼠心肌损伤模型,假手术组不结扎及穿孔。所有小鼠在术后24 h处死并留取血液及心肌标本。ELISA检测血清中炎症因子及心肌损伤标志物水平,RT-qPCR检测心肌组织自噬标志物LC3B、p62的mRNA表达,Western blot检测心肌组织中LC3B、Beclin-1、p62、p-AMPK及AMPK的蛋白表达,苏木精-伊红染色观察心肌组织的病理变化。

结果与结论:①脓毒症小鼠心肌损伤模型中自噬处于抑制状态;②与假手术组相比,模型组血清肿瘤坏死因子α、白细胞介素1β、白细胞介素6、肌酸激酶同工酶、肌钙蛋白T水平均升高(P < 0.05),p62、LC3Ⅱ/LC3Ⅰ、p-AMPK/AMPK无显著变化(P > 0.05);③与模型组相比,二甲双胍组肿瘤坏死因子α、白细胞介素6、肌酸激酶同工酶、肌钙蛋白T、p62水平均下降(P < 0.05),LC3Ⅱ/LC3Ⅰ、p-AMPK/AMPK、Beclin-1均升高(P < 0.05);④与二甲双胍组相比,二甲双胍+3-甲基腺嘌呤组肿瘤坏死因子α、白细胞介素6、肌酸激酶同工酶、肌钙蛋白T、p62均升高(P < 0.05),LC3Ⅱ/LC3Ⅰ、Beclin-1均下降(P < 0.05);⑤假手术组心肌纤维正常,模型组心肌纤维排列紊乱,间质水肿,见大量炎症细胞浸润;二甲双胍组局部见少量空泡状改变;二甲双胍+3-甲基腺嘌呤组心肌纤维排列稍紊乱,见较多空泡状改变;⑥以上结果表明,二甲双胍预处理可能通过激活AMPK信号通路诱导自噬减轻脓毒症小鼠心肌损伤。

https://orcid.org/0009-0000-5657-6744(田勇)

中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程

关键词: 二甲双胍, 自噬, 脓毒症, 炎症反应, 心肌损伤

Abstract: BACKGROUND: Sepsis complicated by myocardial injury is characterized by a high mortality. Metformin can prevent sepsis-induced myocardial dysfunction by exerting anti-inflammatory effects, improving oxidative stress, and reducing apoptosis. However, it is unclear whether metformin-induced autophagy plays an important role in the protective effect against sepsis-induced myocardial injury.
OBJECTIVE: To explore the effect of metformin pretreatment on myocardial injury in septic mice.
METHODS: A total of 40 male Kunming mice were randomly divided into sham operation group, model group, metformin group, and metformin+3-methyladenine group, with 10 mice in each group. The latter two groups were intraperitoneally injected with metformin for 14 days at a fixed time every day, and the metformin+3-methyladenine group was intraperitoneally injected with 3-methyladenine 1 hour before modeling. Twenty-four hours after the last injection of metformin, cecal ligation and perforation were used to construct a model of myocardial injury in septic mice. The sham operation group was not ligated and perforated. All mice were sacrificed 24 hours after surgery, and blood and myocardial specimens were collected. The levels of inflammatory factors and myocardial injury markers in serum were detected by ELISA. The mRNA expression of autophagy markers LC3B and p62 in myocardial tissue was detected by RT-qPCR. The protein expression of LC3B, Beclin-1, p62, p-AMPK, and AMPK in myocardial tissue was detected by western blot. The pathological changes in myocardial tissue were detected by hematoxylin-eosin staining.
RESULTS AND CONCLUSION: Autophagy was inhibited in septic mice with myocardial injury. Compared with the sham operation group, the levels of serum tumor necrosis factor-α, interleukin-1β, interleukin-6, creatine kinase isoenzyme, and troponin T were increased in the model group (P < 0.05), but there was no significant difference in p62, LC3II/LC3I, and p-AMPK/AMPK between the two groups (P > 0.05). Compared with the model group, the levels of tumor necrosis factor-α, interleukin-6, creatine kinase isoenzyme, troponin T, and p62 were decreased in the metformin group (P < 0.05), while LC3II/LC3I, p-AMPK/AMPK and Beclin-1 level were increased (P < 0.05). Compared with the metformin group, the levels of tumor necrosis factor-α, interleukin-6, creatine kinase isoenzyme, troponin T, and p62 were increased in the metformin+3-methyladenine group (P < 0.05), while LC3II/LC3I and Beclin-1 level were decreased (P < 0.05). Myocardial hematoxylin-eosin staining indicated that myocardial fibers arranged normally in the sham operation group, but disorderedly in the model group, with interstitial edema and a large number of infiltrated inflammatory cells. A small amount of vacuolar changes were observed in the metformin group. The arrangement of myocardial fibers in the metformin+3-methyladenine group was slightly disordered, with more vacuolar changes. To conclude, metformin pretreatment may reduce myocardial injury in septic mice by activating the AMPK signaling pathway and inducing autophagy.

Key words: metformin, autophagy, sepsis, inflammatory response, myocardial injury

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