摘要
Oxidative stress (OS) is regarded as a major contributor to granulosa cellapoptosis in ovarian disease. 1-Deoxynojirimycin (1-DNJ), a naturally occurring plant alkaloid, exhibits antioxidant, anti-inflammatory, and metabolism-modulating properties. Mitochondria and endoplasmic reticulum (ER), crucial organelles regulating oxidative balance, interact through mitochondria-associated endoplasmic reticulum membranes (MAMs) for signaling and molecular exchange. However, it remains unclear whether 1-DNJ attenuates oxidative damage in ovarian granulosa cells (GCs) via MAMs-mediated ER–mitochondria crosstalk, which needs further exploration. This study aimed to investigate the mechanisms by which 1-DNJ affects oxidative damage and apoptosis induced by OS in porcine follicular GCs by regulating mitochondrial function, MAMs, and ER interactions. Here, we found that GCs suffered from OS, accompanied by the up-regulation of ROS and MDA, alongside reduced activity of antioxidant enzymes (CAT and T-SOD). Further studies revealed that the up-regulation of MAMs proteins (MFN2, MCU, and VDAC1) and pro-apoptosis proteins (BAX and Cleaved-capase3), along with increased mitochondrial ROS and Ca2+ levels, led to the down-regulation of MMP and ATP content. These, in turn, triggered mitochondrial dysfunction, and MAMs destabilization, and subsequent apoptosis. Additionally, the up-regulation of the protein levels of P-PERK/PERK, GRP78, ATF4, and CHOP protein expression activated the PERK-ATF4 signaling pathway, which triggered endoplasmic reticulum stress (ERS). Conversely, 1-DNJ alleviated H2O2-induced mitochondrial and MAMs dysfunction and ERS, which in turn attenuated apoptosis. Further, ATF4 knockdown inhibited MFN2 protein expression, which attenuated H2O2-induced MMP inhibition, Ca2+ overload, ROS production, and mitochondrial damage. In summary, 1-DNJ mitigated OS-induced mitochondrial dysfunction in GCs and regulated ER–mitochondrial communication through MAMs, reducing OS-induced apoptosis. The present study demonstrates that 1-DNJ protects ovarian GCs from OS-induced damage by modulating ER and mitochondrial homeostasis through MAMs, offering new perspectives and a theoretical basis for the treatment of ovarian diseases.
摘要译文
氧化应激（OS）被认为是卵巢疾病中颗粒细胞凋亡的主要因素。1-脱氧诺霉素（1-DNJ）是一种天然存在的植物生物碱，具有抗氧化剂，抗炎和代谢调节特性。线粒体和内质网（ER），调节氧化平衡的关键细胞器，通过线粒体相关的内质网膜（MAMS）进行信号传导和分子交换。但是，目前尚不清楚1-DNJ是否通过MAMS介导的ER-蒙膜章节串扰来减弱卵巢颗粒细胞（GC）的氧化损伤，这需要进一步探索。这项研究旨在研究1-DNJ通过调节线粒体功能，MAM和ER相互作用来影响OS在猪卵泡GC中诱导的氧化损伤和凋亡的机制。在这里，我们发现GC患有OS，伴随着ROS和MDA的上调，以及抗氧化酶的活性降低（CAT和T-SOD）。进一步的研究表明，MAMS蛋白（MFN2，MCU和VDAC1）和促凋亡蛋白（Bax和Cleaved-Capase3）的上调，以及线粒体ROS和Ca2+水平的增加，导致MMP和ATP含量下调。这些反过来触发了线粒体功能障碍，妈妈不稳定以及随后的凋亡。另外，P-Perk/Perk，Grp78，ATF4和Chop蛋白表达的蛋白质水平的上调激活了PERK-ATF4信号通路，这触发了内质网应激（ERS）。相反，1-DNJ减轻了H2O2诱导的线粒体和MAMS功能障碍和ER，这又减弱了凋亡。此外，ATF4敲低抑制了MFN2蛋白的表达，后者减弱了H2O2诱导的MMP抑制作用，Ca2+过载，ROS产生和线粒体损伤。总而言之，1-DNJ减轻了OS诱导的GCS中的线粒体功能障碍，并通过MAMS调节了ER - 蒙上软骨通信，从而减少了OS诱导的凋亡。本研究表明，1-DNJ通过通过MAMS调节ER和线粒体稳态来保护卵巢GC免受OS诱导的损害，从而提供新的观点和治疗卵巢疾病的理论基础。