| 摘要: |
| 目的 观察小鼠在慢性应激时及应激停止后下丘脑食欲调节因子的变化，并初步探索应激依赖性的食欲变化机制。方法 将32只雄性C57BL/6小鼠随机分为对照（Ctrl）组及慢性不可预知温和应激（CUMS）组，每组16只。CUMS组小鼠予以CUMS（持续11周）建立应激模型，Ctrl组正常饲养。记录小鼠摄食量和体重。通过悬尾实验和强迫游泳实验验证CUMS模型是否构建成功。第12周时从两组各随机取8只小鼠收集全脑、下丘脑组织待测；两组各剩余的8只小鼠重新编组为应激停止（C-CUMS）组和应激停止对照（C-Ctrl）组，继续观察3周后，取全脑、下丘脑组织待测。通过qPCR和免疫组织化学染色方法检测小鼠下丘脑中食欲调节因子食欲素1型受体（OX1R）、瘦素受体（LEPR）和刺鼠相关蛋白（AgRP）的表达情况。结果 应激第2～11周，CUMS组小鼠累积摄食量高于Ctrl组（均P＜0.05），11周内两组小鼠体重差异无统计学意义（均P＞0.05）。11周后CUMS组小鼠悬尾不动时间和水中漂浮时间均长于Ctrl组小鼠（均P＜0.01），提示造模成功。造模成功后，CUMS组小鼠下丘脑组织中促食欲因子AgRP mRNA、OX1R mRNA表达量高于Ctrl组（均P＜0.01），抑食欲因子LEPR mRNA表达量低于Ctrl组（P＜0.01）；CUMS组小鼠下丘脑弓状核中AgRP蛋白表达水平高于Ctrl组（P＜0.05），LEPR蛋白表达水平低于Ctrl组（P＜0.01）。应激停止3周后，C-CUMS组小鼠累积摄食量少于C-Ctrl组（P＜0.05），体重低于C-Ctrl组（P＜0.05）。C-CUMS组小鼠LEPR mRNA表达量高于C-Ctrl组（P＜0.01），AgRP mRNA、OX1R mRNA表达量与C-Ctrl组相比差异无统计学意义（均P＞0.05）；C-CUMS组小鼠AgRP蛋白表达水平与C-Ctrl组比较差异无统计学意义（P＞0.05），LEPR蛋白表达水平高于C-Ctrl组（P＜0.01）。结论 CUMS导致小鼠食欲增加，其机制可能与LEPR和AgRP的功能调节有关；应激停止后其食欲下降，机制可能涉及LEPR的功能调节。 |
| 关键词: 慢性不可预知温和应激 食欲调节因子 下丘脑 食欲素1型受体 瘦素受体 刺鼠相关蛋白 |
| DOI：10.16781/j.CN31-2187/R.20220935 |
| 投稿时间：2022-12-16修订日期：2023-03-07 |
| 基金项目:国家科技创新2030—“脑科学与类脑研究”重大项目（2022ZD0208100）;海军军医大学（第二军医大学）“远海领航”军事医学人才项目（2019YH02）. |
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| Effects of chronic stress on hypothalamic appetite-regulating factors in mice |
| YIN Lifeng1,2,LIU Qing2,ZHU Jian2,WANG Chenxu2,ZHENG Tianyu2,ZHU Yongheng1*,MO Fengfeng2* |
(1. College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China;
2. Department of Naval Nutrition and Food Hygiene, Faculty of Naval Medicine, Naval Medical University (Second Military Medical University), Shanghai 200433, China
*Corresponding authors) |
| Abstract: |
| Objective To explore the effects of chronic stress and stress cessation on hypothalamic appetite regulators in mice, and to explore the stress-dependent mechanism of appetite change. Methods A total of 32 male C57BL/6 mice were randomly divided into control (Ctrl) group (n＝16) and chronic unpredictable mild stress (CUMS) group (n＝16). The mice in the CUMS group were given CUMS to establish the stress model, and those in the Ctrl group were fed normally. The food intake and weight of mice were recorded. The CUMS model was verified through tail suspension experiments and forced swimming experiments. Eight mice in the Ctrl group and 8 mice in the CUMS group were randomly sacrificed at the 12th week. The Ctrl group was re-grouped into the cessation-control (C-Ctrl) group (n＝8), the CUMS group was re-grouped into the cessation-stress (C-CUMS) group (n＝8), and the mice were sacrificed at the 15th week. The mRNA and protein levels of appetite-regulating factors, including orexin 1 receptor (OX1R), leptin receptor (LEPR) and agouti-related protein (AgRP) in the hypothalamus, were detected by quantitative polymerase chain reaction and immunochemistry. Results From week 2 to week 11 of stress, the food intake of the mice in the CUMS group was significantly higher than that in the Ctrl group (all P＜0.05), while there was no significant difference in body weight between the 2 groups within 11 weeks (all P＞0.05). Compared with the Ctrl group, the immobility durations of forced swimming and tail suspension of the CUMS group were markedly longer after 11 weeks (both P＜0.01), indicating successful modeling. AgRP and OX1R mRNA expression in the hypothalamus of the CUMS group was significantly increased (both P＜0.01), while LEPR mRNA expression was significantly decreased (P＜0.01); AgRP protein in the hypothalamic arcuate nucleus of the CUMS group was significantly higher than that of the Ctrl group (P＜0.05), and LEPR protein was markedly lower than that of the Ctrl group (P＜0.01). However, after 3 weeks of stress cessation, the C-CUMS group had less food intake and lower body weight than the C-Ctrl group (both P＜0.05). The LEPR mRNA of the C-CUMS group was significantly increased (P＜0.01), while AgRP and OX1R mRNA were not significantly different (both P＞0.05). There was no significant difference in AgRP protein levels between the C-CUMS group and the C-Ctrl group (P＞0.05), while LEPR protein level of the C-CUMS group was significantly higher than that of the C-Ctrl group (P＜0.01). Conclusion CUMS can lead to increased appetite in mice, which may involve the functional regulation of LEPR and AgRP. After the stress cessation, the appetite decreases, which may involve the functional regulation of LEPR. |
| Key words: chronic unpredictable mild stress appetite regulating factors hypothalamus orexin 1 receptor leptin receptor agouti-related protein |
