Study for the etiology of polycystic ovary using a rat model

多囊卵巢综合征（PCOS）的特征之一是在生长和闭锁的各个阶段存在囊性卵泡，已知闭锁是细胞凋亡和组织重塑的结果。为了进一步探讨卵泡闭锁的过程中，我们比较了卵巢Fas，Fas配体（FasL），Casapse-8和膜型1基质金属蛋白酶（MT 1-MMP）的表达和定位在大鼠脱氢表雄酮（DHEA）作为PCOS模型，并在对照组大鼠。我们发现，TdT介导的dUTP-生物素缺口末端标记（TUNEL）阳性卵泡的数量从PCOS大鼠卵巢显著高于对照组大鼠，卵巢的FasL mRNA和蛋白，加工caspase-8蛋白和MT 1-MMP mRNA的水平。相应地，我们还观察到MTI-MMP催化活性水平的增加和caspase-8蛋白水平的降低。此外，免疫组化分析显示，MT 1-MMP和F ...更多信息 asL与PCOS卵巢闭锁卵泡内TUNEL阳性凋亡颗粒细胞共定位。我们的研究结果表明，在DHEA诱导的PCOS样条件下，Fas/FasL/Caspase-8（死亡受体依赖性）途径是卵泡闭锁的关键，MT 1-MMP水平的增加可能在结构性黄体溶解过程中的组织重塑中起重要作用。胰岛素抵抗在生殖功能中的作用已引起人们的关注。但脂联素在卵巢中的表达及其在生殖功能中的作用尚不完全清楚。未成熟Zucker fa/fa大鼠的卵巢显示与瘦大鼠相比闭锁卵泡数量、总卵泡数量和闭锁卵泡/总卵泡的百分比显著增加。fa/fa大鼠血清脂联素表达随年龄增长而显著降低。脂联素及其受体在大鼠卵巢颗粒细胞、Thaca细胞和黄体中均有表达。Western blot和实时荧光定量RT-PCR分析显示，高胰岛素血症时，卵巢脂联素及其受体的表达与脂肪组织、肝脏和骨骼肌一样均降低。总之，本研究首次提供了胰岛素抵抗大鼠卵巢形态学改变及脂联素及其受体表达和调节的改变。因此，胰岛素抵抗可能与生殖功能障碍密切相关，低脂联素水平也可能是Zucker肥胖大鼠不孕和PCOS样状态的主要原因之一。我们研究了促性腺激素释放激素激动剂（GnRHa）影响卵巢过度刺激综合征（OHSS）大鼠模型卵巢血管分布、血管通透性和紧密连接蛋白claudin-5表达的机制。卵巢血管密度和血管内皮面积（百分比）通过免疫组织化学分析血管性血友病因子的分布进行评估，而血管通透性根据伊文思蓝的泄漏进行评估。高剂量PMSG和hCG显著增加卵巢重量、血管通透性、血管密度和血管内皮面积，并显著降低claudin-5蛋白和mRNA的表达。所有这些作用均被GnRHa给药显著且呈剂量依赖性抑制。这表明，claudin-5的表达减少在OHSS中观察到的卵巢血管通透性增加中起着至关重要的作用，并且其表达可以通过GnRHa治疗来调节。事实上，防止紧密连接蛋白在内皮细胞中的重新分布以及由此导致的内皮屏障结构的丧失可能是保护患者在OHSS病例中免受大量血管外液体积聚的关键。少

One of the characteristics of polycystic ovary syndrome (PCOS) is the presence of cystic follicles in various stages of growth and atresia, the latter of which is known to be the result of apoptosis and tissue remodeling. To further investigate the process of follicular atresia, we compared ovarian expression and localization of Fas, Fas ligand (FasL), casapse-8 and membrane-type1 matrix metalloproteinase (MT1-MMP) in rats treated with dehydroepiandrosterone (DHEA) as a model of PCOS, and in control rats. We found that the numbers of TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive follicles were significantly higher in ovaries from PCOS rats than in those from control rats, as were ovarian levels of FasL mRNA and protein, processed caspase-8 protein and MT1-MMP mRNA. Correspondingly, we also observed an increase in the level of MTI-MMP catalytic activity and a decrease in the level of pro-caspase-8 protein. In addition, immunohistochemical analyses showed that MT1-MMP and F … More asL co-localize with TUNEL-positive apoptotic granulosa cells within atretic follicles of PCOS ovaries. Our results suggest that under the PCOS-like conditions induced by DHEA, the Fas/FasL/Caspase-8 (death receptor dependent) pathway is pivotal for follicular atresia, and that increased levels of MT1-MMP likely play an important role in tissue remodeling during structural luteolysisRecently adiponectin has been suggested to play important role in insulin sensitivity. And insulin resistance has been attracted attention in reproductive function. But the expression of adiponectin in ovaries and adiponectin function in reproductive function are not fully understood. Ovaries of immature Zucker fa/fa rats showed significantly increased number of atretic follicles, number of total follicles and the percentage of atretic follicels/total follicles compared to lean rats. Serum adiponectin expression in fa/fa rats was significantly decreased as they became older. Adiponectin and its receptors are expressed in rat ovaries of granulosa cells, thaca cells and colupus luteums. Furthermore western blot and realtime RT-PCR analysis showed the expression of adiponectin and its receptors in ovaries were decreased under hyperinsulinemia condition like adipose tissue, liver and skeletal muscle. Overall our present data firstly provide the altered ovarian morphology and altered expression and regulation of adiponectin and its receptors in insulin resistant rat ovaries. Thus insulin resistant might closely related to reproductive dysfunction and low adiponectin profile also might be one one of the main causes of infertility and PCOS like condition in Zucker fatty rats.We investigated the mechanism by which a GnRH agonist (GnRHa) affects ovarian vascularity, vascular permeability, and expression of the tight junction protein claudin-5 in a rat model of ovarian hyperstimulation syndrome (OHSS). Ovarian vascular density and vessel endothelial area (percent) were assessed by immunohistochemical analysis of the distribution of von Willebrand factor, whereas vascular permeability was evaluated based on leakage of Evans blue. High doses of PMSG and hCG significantly increased ovarian weight, vascular permeability, vascular density, and the vessel endothelial area and significantly reduced expression of claudin-5 protein and mRNA. All of these effects were significantly and dose-dependently inhibited by administration of GnRHa. This suggests that reduced expression of claudin-5 plays a crucial role in the increased ovarian vascular permeability seen in OHSS and that its expression can be modulated by GnRHa treatment. Indeed, preventing redistribution of tight junction proteins in endothelial cells and the resultant loss of endothelial barrier architecture might be the key to protecting patients against massive extravascular fluid accumulation in cases of OHSS. Less