Background:In the mammalian ovary, 99% of follicles are removed through follicular atresia caused by granulosa cell apoptosis. Results: Bim EL can induce porcine granulosa cell apoptosis, and its expression is regulated by FSH via the PI3K/Akt/FoxO3a pathway. Conclusion:The pro-apoptotic protein Bim EL is involved in porcine granulosa cell apoptosis. Significance: This provides novel insights into the molecular mechanisms underlying follicular atresia.

Oxidative stress is emerging as a crucial contributor to the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD), but the molecular mechanisms underlying the disturbed redox homeostasis in cystic cells remain elusive. Here, we identified the impaired activity of the NRF2 (nuclear factor erythroid 2–related factor 2) antioxidant pathway as a driver of oxidative damage and ADPKD progression. Using a quantitative proteomic approach, together with biochemical analyses, we found that increased degradation of NRF2 protein suppressed the NRF2 antioxidant pathway in ADPKD mouse kidneys. In a cohort of patients with ADPKD, reactive oxygen species (ROS) frequently accumulated, and their production correlated negatively with NRF2 abundance and positively with disease severity. In an orthologous ADPKD mouse model, genetic deletion of Nrf2 further increased ROS generation and promoted cyst growth, whereas pharmacological induction of NRF2 reduced ROS production and slowed cystogenesis and disease progression. Mechanistically, pharmacological induction of NRF2 remodeled enhancer landscapes and activated NRF2-bound enhancer-associated genes in ADPKD cells. The activation domain of NRF2 formed phase-separated condensates with MEDIATOR complex subunit MED16 in vitro, and optimal Mediator recruitment to genomic loci depended on NRF2 in vivo. Together, these findings indicate that NRF2 remodels enhancer landscapes and activates its target genes through a phase separation mechanism and that activation of NRF2 represents a promising strategy for restoring redox homeostasis and combatting ADPKD.

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Endothelial cells regulate vascular tone by producing both relaxing and contracting factors to control the local blood flow. Hypertension is a common side effect of mTORC1 (mammalian target of rapamycin complex 1) inhibitors. However, the role of endothelial mTORC1 in hypertension remains elusive. The present study aimed to determine the role of endothelial mTORC1 in Ang II (angiotensin II)–induced hypertension and the underlying mechanism. Endothelial mTORC1 activity was increased by Ang II both in vitro and in vivo. Blood pressure was higher in Tie-2-Cre –mediated regulatory associated protein of mTOR (mammalian target of rapamycin; Raptor ) heterozygous-deficient ( Tie2Cre-Raptor KD ) mice than control mice both before and after Ang II infusion. Acetylcholine-evoked endothelium-dependent relaxation of mesenteric arteries was impaired in Tie2Cre-Raptor KD mice. Treatment with indomethacin or a specific COX (cyclooxygenase)-2 inhibitor, NS-398, but not L-NG-nitroarginine methyl ester reduced endothelium-dependent relaxation in Raptor flox /− mice to a similar extent as in Tie2Cre-Raptor KD mice. Metabolomic profiling revealed that the plasma content of prostaglandin E 2 was reduced in Tie2Cre-Raptor KD mice with or without Ang II infusion. In endothelial cells, reduction of the protein level of YAP (yes-associated protein) with siRNA -mediated RPTOR deficiency was autophagy dependent and transcriptionally regulated the expression of COX-2 and mPGES-1 (microsomal prostaglandin E synthase-1). Hence, overexpression of YAP in endothelial cells enhanced the mRNA and protein levels of COX-2 and mPGES-1 and reversed the endothelial dysfunction and hypertension in Tie2Cre-Raptor KD mice. The present results demonstrate that suppression of mTORC1 activity in endothelial cells reduces prostaglandin E 2 production and causes hypertension by reducing YAP-mediated COX-2/mPGES-1 expression.

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