Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013.
Shanghai Pharmaceutical Clinical Research Center Co., Ltd., Shanghai 200032.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2022 Apr 28;47(4):443-452. doi: 10.11817/j.issn.1672-7347.2022.210231.
During pregnancy, pregnant women are prone to stress reactions due to external stimuli, affecting their own health and fetal development. At present, there is no good treatment for the stress reactions from pregnant women during pregnancy. This study aims to explore the effect of probiotics on abnormal behavior and hippocampal injury in pregnant stressed offspring.
SD pregnant rats were divided into a control group, a stress group, and a probiotics group, with 6 rats in each group. The control group was untreated; the stress group was given restraint stress on the 15th-20th day of pregnancy; the probiotics group was given both bifidobacterium trisporus capsules and restraint stress on the 15th-20th day of pregnancy, and the offspring continued to be fed with probiotics until 60 days after birth (P60). The offspring rats completed behavioral tests such as the open field test, the elevated plus maze test, the new object recognition test, and the barnes maze test at 60-70 d postnatally. Nissl's staining was used to reflect the injury of hippocampal neurons; immunohistochemical staining was used to detect the expression of microglia marker ionized calcium binding adapter molecule 1 (IBA-1) which can reflect microglia activation; ELISA was used to detect the content of plasma TNF-α and IL-1β; Western blotting was used to detect the expression of Bax, Bcl-2, and caspase-3.
The retention time of offspring rats in the stress group in the central area of the open field was significantly less than that in the control group (<0.01), and the retention time of offspring rats in the probiotic group in the central area of the open field was significantly more than that in the stress group (<0.05). The offspring rats in the stress group stayed in the open arm for a shorter time than the control group (<0.05) and entered the open arm less often than the control group (<0.01); the offspring rats in the probiotic group stayed in the open arm for a longer time than the stress group and entered the open arm more often than the stress group (both <0.05). The discrimination ratio for new to old objects in the offspring rats of the stress group was significantly lower than that of the control group (<0.01), and the discrimination ratio for new to old objects in the offspring rats of the probiotic group was significantly higher than that of the stress group (<0.05). The offspring rats in the stress group made significantly more mistakes than the control group (<0.05), and the offspring rats in the probiotic group made significantly fewer mistakes than the stress group (<0.05). Compared with the control group, the numbers of Nissl bodies in CA1, CA3, and DG area were significantly reduced in the offspring rats of the stress group (all <0.001), the number of activated microglia in DG area of hippocampus was significantly increased (<0.01), the contents of TNF-α and IL-1β in peripheral blood were significantly increased (<0.05 or <0.01), the protein expression level of Bcl-2 was significantly down-regulated, and the protein expression levels of Bax and caspase-3 were significantly up-regulated (all <0.001). Compared with the stress group, the numbers of Nissl bodies in CA1, CA3, and DG area were significantly increased in the probiotic group offspring rats (<0.001, <0.01, <0.05), the number of activated microglia in the DG area of hippocampus was significantly reduced (<0.05), and the TNF-α and IL-1β levels in peripheral blood were significantly decreased (both <0.05), the protein expression level of Bcl-2 was significantly up-regulated, and the protein expression levels of Bax and caspase-3 were significantly down-regulated (all <0.001).
Probiotic intervention partially ameliorated anxiety and cognitive impairment in rats offspring of pregnancy stress, and the mechanism may be related to increasing the number of neurons, inhibiting the activation of hippocampal microglia, and reducing inflammation and apoptosis.
孕妇在妊娠期间易受到外界刺激产生应激反应，影响自身健康和胎儿发育。目前，针对孕妇妊娠期间的应激反应尚无良好的治疗方法。本研究旨在探讨益生菌对孕鼠应激后代异常行为和海马损伤的影响。
将 SD 孕鼠分为对照组、应激组和益生菌组，每组 6 只。对照组不做处理；应激组于妊娠第 15-20 天给予束缚应激；益生菌组于妊娠第 15-20 天给予双歧杆菌三联活菌胶囊并给予束缚应激，后代继续给予益生菌喂养至出生后 60 天（P60）。子代大鼠在生后 60-70 日龄完成旷场实验、高架十字迷宫实验、新物体识别实验和巴恩斯迷宫实验等行为学测试。尼氏染色反映海马神经元损伤；免疫组织化学染色检测小胶质细胞标志物离子钙结合接头分子 1（IBA-1）的表达，反映小胶质细胞激活；ELISA 检测血浆 TNF-α和 IL-1β含量；Western blot 检测 Bax、Bcl-2 和 caspase-3 的表达。
应激组子代大鼠在旷场中央区域的停留时间明显少于对照组（<0.01），益生菌组子代大鼠在旷场中央区域的停留时间明显多于应激组（<0.05）。应激组子代大鼠在开放臂停留时间短于对照组（<0.05），进入开放臂的次数少于对照组（<0.01）；益生菌组子代大鼠在开放臂停留时间长于应激组，进入开放臂的次数多于应激组（均<0.05）。应激组子代大鼠对新物体与旧物体的辨别率明显低于对照组（<0.01），益生菌组子代大鼠对新物体与旧物体的辨别率明显高于应激组（<0.05）。应激组子代大鼠犯错明显多于对照组（<0.05），益生菌组子代大鼠犯错明显少于应激组（<0.05）。与对照组相比，应激组子代大鼠 CA1、CA3 和 DG 区的尼氏小体数量明显减少（均<0.001），DG 区海马小胶质细胞激活数量明显增加（<0.01），外周血 TNF-α和 IL-1β含量明显升高（均<0.05 或 <0.01），Bcl-2 蛋白表达水平明显下调，Bax 和 caspase-3 蛋白表达水平明显上调（均<0.001）。与应激组相比，益生菌组子代大鼠 CA1、CA3 和 DG 区的尼氏小体数量明显增加（均<0.001、<0.01、<0.05），DG 区海马小胶质细胞激活数量明显减少（<0.05），外周血 TNF-α和 IL-1β水平明显降低（均<0.05），Bcl-2 蛋白表达水平明显上调，Bax 和 caspase-3 蛋白表达水平明显下调（均<0.001）。
益生菌干预部分改善了孕鼠应激后代的焦虑和认知障碍，其机制可能与增加神经元数量、抑制海马小胶质细胞激活、减轻炎症和凋亡有关。
