HSP70在多囊卵巢综合征发病机制中的研究

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. However, the etiology and pathology are still unclear. Nevertheless, there are hints showed insulin resistance, chronic inflammation and oxidative stress are at least partially responsible for the PCOS. Furthermore, multi-dysfunctions of granulosa cells are also considered as another potential reason for PCOS. All those pathological changes and dysfunctions are related to heat shock protein70 (HSP70). .Our previous study found that HSP70 levels were abnormal in the ovaries of PCOS rats and increased in granulosa cells of PCOS. Therefore, HSP70 is proposed to play an important role in the pathology of PCOS through insulin resistance, chronic inflammation or oxidative stress. Moreover, the abnormal apotosis, steroid hormone synthesis and insulin resistance of the granulosa cells should be possible to be altered by changing the expression of HSP70. The purpose of this progect is: (1) by changing the HSP70 expression level induced by chemicals in vivo in PCOS rats, the connection between the pathology of PCOS and pathways of HSP70 could be studied through the levels of steroid hormone, insulin resistance, inflammatory cytokins and oxidative stress indicators. (2) to find out the role of HSP70 in the functionality of granulosa cells through overexpression/knockdown of HSP70 and unveil how HSP70 participate in apotosis, steroid hormone synthesis and insulin resistance in the granulosa cells.

多囊卵巢综合征（PCOS）是育龄期妇女无排卵最常见的病因，但目前发病机制仍不清楚。胰岛素抵抗、慢性炎症、氧化应激是PCOS主要特征，同时PCOS的颗粒细胞存在多方面功能障碍，上述病理变化及功能障碍均涉及HSP70。我们前期研究发现HSP70在PCOS大鼠卵巢中异常表达，颗粒细胞中表达升高。因此我们推断HSP70在PCOS的发病机制中可能具有重要作用，改变PCOS颗粒细胞中的HSP70的表达水平将有可能改变颗粒细胞功能。本研究拟：①通过改变PCOS大鼠体内HSP70的表达水平，观察甾体激素、胰岛素抵抗、炎症因子水平及氧化应激水平的变化，分析HSP70与其相关性，推测HSP70在PCOS发病机制中的可能途径及作用机理；②通过改变PCOS大鼠颗粒细胞的HSP70的表达水平，观察颗粒细胞甾体激激素合成能力、胰岛素抵抗水平及颗粒细胞凋亡水平，探讨HSP70对PCOS颗粒细胞功能的影响。

多囊卵巢综合征(PCOS)是育龄期妇女无排卵最常见的病因，但目前发病机制仍不清楚。胰岛素抵抗、慢性炎症、氧化应激是PCOS主要特征,同时PCOS的颗粒细胞存在多方面功能障碍，上述病理变化及功能障碍均涉及HSP70。本研究通过皮下注射脱氢表雄酮（DHEA）0.6mg/100g方法构建PCOS模型大鼠，观察PCOS大鼠体内HSP70的与炎症因子水平、氧化应激水平及激素水平的相关性，并通过给予谷氨酰胺（Gln）干预，观察Gln对PCOS模型大鼠炎症状态和氧化应激状态的调节作用及HSP70的水平变化。结果发现PCOS模型组大鼠卵巢组织形态呈现多囊样改变，血清性激素水平与PCOS患者类似，表现为睾酮、黄体生成素浓度明显升高。与正常对照组相比，PCOS组大鼠血清MDA、NO、NOS浓度均明显升高，SOD浓度下降，差异有统计学意义(P＜0.05)；与PCOS组相比，PCOS+Gln组大鼠血清MDA、NO、NOS浓度均明显下降，而SOD浓度升高，差异有统计学意义(P＜0.05)。PCOS组和PCOS+Gln组大鼠血清IL-6、IL-18、CRP、TNF-α浓度均明显升高，差异有统计学意义（P＜＝0.05）；与PCOS组相比，PCOS+Gln组大鼠血清IL-6、IL-18、CRP、TNF-α浓度均明显下降，差异有统计学意义（P＜＝0.05）。免疫组化显示PCOS组HSP70表达水平明显高于正常对照组（P＜0.01），然而血清中HSP70的浓度则低于正常对照组(P=0.002)，Gln则可明显明显降低PCOS大鼠血清中HSP70的水平（P＜0.01）。Spearman相关分析发现血清HSP70与血清雄激素、LH及所有检测的炎症因子均呈强负相关关系。 说明DHEA可诱导比较稳定的PCOS大鼠动物模型。PCOS大鼠血清和卵巢组织炎症因子IL-6、IL-18、CRP、TNF- α水平异常升高，谷氨酰胺能够缓解PCOS大鼠炎症状态。PCOS大鼠血清氧化应激状态增强，MDA、NO、NOS水平显著升高，SOD水平显著下降，谷氨酰胺能够缓解PCOS大鼠体内氧化应激状态。谷氨酰胺可改变大鼠体内HSP70的表达水平，而HSP70的异常表达与睾酮和炎症因子有关，提示HSP70可能在PCOS的病理过程中起重要作用。