糖皮质激素损伤卵子发育能力及着床前束缚应激增加后代焦虑行为的机制研究

发布时间：2018-01-25 02:03

本文关键词： 着床前束缚应激糖皮质激素后代焦虑卵母细胞发育能力胚胎培养凋亡 Fas/FasL 小鼠　出处：《山东农业大学》2016年博士论文　论文类型：学位论文

【摘要】：PART I:研究表明应激可以导致糖皮质激素过量分泌并损伤卵母细胞发育能力。我们实验室前期工作发现注射糖皮质激素(皮质醇)同样导致小鼠卵母细胞发育能力下降,但体外成熟过程中添加应激生理浓度的糖皮质激素并不影响卵母细胞的成熟和胚胎的发育。本实验主要通过检测注射皮质醇后小鼠卵母细胞的发育能力,卵巢细胞凋亡情况,Fas/Fas L信号通路的激活来探索糖皮质激素损伤卵母细胞发育能力的具体机制。结果显示注射糖皮质激素(皮质醇)显著降低雌性小鼠(a)卵母细胞发育能力,(b)血清和卵巢中E2/P4的比例,(c)壁颗粒细胞中胰岛素样生长因子1(IGF1)、脑源性营养因子(BDNF)及糖皮质激素受体(GR)的表达。同时显著升高(a)血清和卵巢中皮质醇的含量,(b)壁颗粒细胞和卵丘细胞的凋亡比例,(c)体外成熟培养过程中卵丘细胞分泌的Fas L,(d)壁颗粒细胞、卵丘细胞和卵母细胞中Fas的表达。当给Fas L基因突变小鼠(gld小鼠)注射皮质醇后,发现其卵母细胞发育能力的削弱程度、壁颗粒细胞和卵丘细胞的凋亡比例与野生型相比都有很大幅度的缓解。由此可以得出以下结论:糖皮质激素是通过激活Fas系统导致卵巢细胞凋亡进而损伤卵母细胞发育潜能。到目前为止,本实验是首次揭示糖皮质激素降低卵母细胞发育能力的机制,这将有助于进一步理解糖皮质激素在应激相关疾病中作用。PART II:人类流行病学研究表明产前应激可能会损伤情感发育,增加后代患抑郁症、焦虑症、精神分裂症、自闭症的机率。但是产前应激影响后代行为和神经内分泌系统的机制尚不十分清楚。另外,大多数这方面的研究都集中于妊娠晚期。关于着床前应激对后代影响的研究很少,而有关这方面的体外试验更是缺乏。本实验主要研究着床前心理应激是否影响后代焦虑行为,并且运用体内和体外外两种模型研究后代行为的改变是否是通过应激增加糖皮质激素的分泌引起的。结果表明着床前应激和体外培养胚胎过程中添加糖皮质激素(皮质酮)都可以增加后代焦虑行为,导致后代海马区糖皮质激素受体(GR)和脑源性营养因子(BDNF)的下调,并促进糖皮质激素的分泌。而且体外培养过程中添加皮质酮会下调胚胎内糖皮质激素受体的表达。由此可以得出以下结论:着床前心理应激是通过促进妊娠母鼠糖皮质激素的分泌,进而引起胚胎内糖皮质激素受体表达下降,最终导致后代焦虑水平上升。本研究是首次报道着床前应激和体外培养胚胎时添加糖皮质激素会增加后代的焦虑行为,这些实验结果可以帮助我们进一步理解产前应激影响后代行为的具体机制。
[Abstract]:PART I: studies have shown that stress can cause hypersecretion of glucocorticoids and damage oocyte development. Our laboratory work found that injecting glucocorticoid (cortisol). The development ability of mouse oocytes was also decreased. However, glucocorticoids added to stress physiological concentration during in vitro maturation did not affect the maturation of oocytes and the development of embryos. Apoptosis of ovarian cells. Activation of Fas/Fas L signaling pathway to explore the specific mechanism of glucocorticoid injury on oocyte development. Oocyte development. The ratio of E _ 2 / P _ 4 in serum and ovary was found in parietal granulosa cells, and insulin-like growth factor-1 (IGF1) was found in parietal granulosa cells. The expression of brain-derived nutrition factor (BDNF) and glucocorticoid receptor (GRG) increased significantly (P < 0.05). Meanwhile, the content of cortisol in serum and ovary was significantly higher than that in parietal granulosa cells and cumulus cells. (C) parietal granulosa cells secreted by cumulus cells during maturation in vitro. The expression of Fas in cumulus cells and oocytes. After injecting cortisol into Fas L mutant mice (GLD mice), it was found that the oocyte development ability was weakened. The percentage of apoptosis in parietal granulosa cells and cumulus cells was significantly alleviated compared with wild-type cells. Glucocorticoid induces ovarian cell apoptosis by activating the Fas system and thus impairs oocyte developmental potential. This experiment is the first to reveal the mechanism of glucocorticoid decreasing oocyte development ability. This will help to further understand the role of glucocorticoids in stress-related diseases .PART II: human epidemiological studies have shown that prenatal stress may damage emotional development and increase depression in offspring. The risk of anxiety, schizophrenia, and autism. But the mechanisms by which prenatal stress affects offspring's behavior and neuroendocrine system are not well understood. Most of these studies have focused on late pregnancy, and little research has been done on the effects of pre-implantation stress on offspring. However, there is a lack of in vitro experiments in this field. This study mainly studied whether pre-implantation psychological stress affects the anxiety behavior of offspring. Two models in vivo and in vitro were used to study whether the behavior change of offspring was caused by stress increasing the secretion of glucocorticoid. The results showed that preimplantation stress and in vitro embryo culture were supplemented with glucocorticoid. (. Corticosterone) can increase anxiety behavior in offspring. This results in down-regulation of glucocorticoid receptor (GRG) and brain-derived nutrition factor (BDNF) in hippocampal area of offspring. And to promote the secretion of glucocorticoids. Moreover, adding corticosterone in vitro can down-regulate the expression of glucocorticoid receptors in embryos. Preimplantation psychological stress promotes the secretion of glucocorticoid in pregnant rats. In turn, the expression of glucocorticoid receptor in embryos decreased. This is the first study to report that pre-implantation stress and glucocorticoid supplementation in vitro embryo culture can increase anxiety behavior in offspring. These results can help us to further understand the specific mechanism of prenatal stress affecting offspring behavior.
【学位授予单位】：山东农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：Q492

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