Abstract：
Understanding of central nervous system mechanisms underlying age-related infertility remains limited. Fibril α-synuclein, distinct from its monomeric form, is implicated in age-related diseases. Notably, fibril α-synuclein spreads among neurons, similar to prions, from damaged old neurons in cortex and hippocampus to healthy neurons. However, less is known whether α-synuclein propagates into oxytocin neurons, which play crucial roles in reproduction. We compared α-synuclein expression in the oxytocin neurons in suprachiasmatic nucleus (SCN), supraoptic nucleus (SON), paraventricular hypothalamic nucleus (PVN), and posterior pituitary (PP) gland of healthy heifers and aged cows to determine its role in age-related infertility. We analyzed mRNA and protein expression, along with Congo red histochemistry and fluorescent immunohistochemistry for oxytocin and α-synuclein, followed by confocal microscopy with Congo red staining. Both mRNA and protein expressions of α-synuclein were confirmed in the bovine cortex, hippocampus, SCN, SON, PVN, and PP tissues. Significant differences in α-synuclein mRNA expressions were observed in the cortex and hippocampus between young heifers and old cows. Western blots showed five bands of α-synuclein, probably reflecting monomers, dimers, and oligomers, in the cortex, hippocampus, SCN, SON, PVN, and PP tissues, and there were significant differences in some bands between the young heifers and old cows. Bright-field and polarized light microscopy did not detect obvious amyloid deposition in the aged hypothalami; however, higher-sensitive confocal microscopy unveiled strong positive signals for Congo red and α-synuclein in oxytocin neurons in the aged hypothalami. α-synuclein was expressed in oxytocin neurons, and some differences were observed between young and old hypothalami.
摘要：
对年龄相关性不孕症的中枢神经系统机制的理解仍然有限。原纤维α-突触核蛋白，与其单体形式不同，与年龄相关的疾病有关。值得注意的是,原纤维α-突触核蛋白在神经元中传播，类似于朊病毒,从皮层和海马中受损的旧神经元到健康的神经元。然而,鲜为人知的是α-突触核蛋白是否传播到催产素神经元，在繁殖中起着至关重要的作用。我们比较了视交叉上核（SCN）中催产素神经元中α-突触核蛋白的表达，视上核(SON),下丘脑室旁核(PVN),以及健康母牛和老年母牛的垂体后叶（PP）腺以确定其在与年龄相关的不育症中的作用。我们分析了mRNA和蛋白质的表达，随着刚果红组织化学和荧光免疫组织化学催产素和α-突触核蛋白，然后用刚果红染色共聚焦显微镜。牛皮质中α-突触核蛋白的mRNA和蛋白表达均得到证实，海马体,SCN,儿子,PVN,和PP组织。在幼小母牛和老牛的皮质和海马中观察到α-突触核蛋白mRNA表达的显着差异。Western印迹显示5条α-突触核蛋白带,可能是反射单体，二聚体,和低聚物，在大脑皮层，海马体,SCN,儿子,PVN,和PP组织，小母牛和老母牛之间的某些条带存在显着差异。明亮的视野和偏振光显微镜未检测到老年下丘脑中明显的淀粉样蛋白沉积；然而，高灵敏的共聚焦显微镜显示了老年下丘脑催产素神经元中刚果红和α-突触核蛋白的强烈阳性信号。α-突触核蛋白在催产素神经元中表达，并且在年轻和老年下丘脑之间观察到一些差异。
