Abstract：
The developmental activation of the corpus luteum (CL) structurally and functionally is critical for the temporally regulated establishment, maintenance, and termination of pregnancy in rats. In this study, we have investigated the possible involvement of autophagy in the regulation of the CL during pregnancy in rats. The expression ratio of microtubule-associated protein light chain 3 (LC3)-II/-I, a widely used indicator of autophagic activity, in the CL remained relatively stable until day 15 of pregnancy. Subsequently, it progressively increased until day 21, and then declined until day 3 postpartum. This fluctuation was closely associated with the tissue weight of the CL rather than progesterone (P4) production activity. Light and electron microscopy revealed the presence of immunoreactive LC3 aggregates and irregularly shaped autolysosome-like microstructures in the cytoplasm of luteal cells during late pregnancy. Notably, a bolus intrabursal injection of the autophagy inhibitor bafilomycin A1 on day 15 of pregnancy resulted in a significant reduction in luteal cell size and disrupted the normal alteration of circulating P4 levels. Consequently, treatment with this inhibitor increased the likelihood of the varied timing (both advanced and delayed) of delivery and led to reduced body weight in neonates when compared with the vehicle-treated control group. Our findings suggest that autophagy in the rat CL contributes to luteal tissue growth, influences P4 production, and thereby fine-tunes the regulation of gestation length in rats.
摘要：
黄体（CL）结构和功能的发育激活对于时间调节的建立至关重要，维护,并终止大鼠的妊娠。在这项研究中,我们研究了自噬可能参与大鼠妊娠期间CL的调节。微管相关蛋白轻链3(LC3)-II/-I的表达率,一种广泛使用的自噬活性指标，在妊娠第15天之前，CL保持相对稳定。随后，它逐渐增加，直到第21天，然后下降，直到产后第3天。这种波动与CL的组织重量而不是孕酮（P4）产生活性密切相关。光镜和电子显微镜显示，在妊娠晚期，黄体细胞质中存在免疫反应性LC3聚集体和不规则形状的自溶酶体样微结构。值得注意的是,在妊娠第15天进行自噬抑制剂巴弗洛霉素A1的囊内推注,可显著减少黄体细胞大小,破坏循环P4水平的正常改变.因此,与媒介物治疗的对照组相比,使用该抑制剂的治疗增加了不同分娩时机(提前和延迟)的可能性,并导致新生儿体重减轻.我们的发现表明，大鼠CL中的自噬有助于黄体组织生长，影响P4生产，从而微调大鼠妊娠长度的调节。
