Armendariz Lois, Chan Alicia, Tjahjono Elissa, Wang Meggie, Kirienko Natalia V
Department of BioSciences, Rice University, 6100 Main St, MS140, Houston, TX, 77005, USA.
bioRxiv. 2025 May 28:2025.05.26.656193. doi: 10.1101/2025.05.26.656193.
Multicellular organisms constantly encounter biotic and abiotic stressors that threaten to disrupt their homeostasis. To counteract this, they have evolved a series of conserved defense networks which monitor organellar function and the accumulation of aberrant molecular signals. As mitochondrial dysfunction can lead to a variety of pathologies, including metabolic impairment, neurodegeneration, cardiovascular disease, cancer, and sensitivity to bacterial infections, understanding these mitochondrial surveillance pathways is crucial. Previous research in our lab established that one such pathway, the Ethanol Stress and Response Element (ESRE), was activated by a broad range of stresses, including exposure to the Gram-negative, opportunistic human pathogen . In this report we show that MDT-15 and its downstream effectors, fatty acid desaturases FAT-6 and FAT-7, were required for ESRE activation. Interestingly, supplementation with fatty acids downstream of FAT-6/FAT-7 activity, from ' PUFA pathway, rescued ESRE activation in their knockdowns. Additionally, disruption of , or its downstream effector by RNAi diminished worm survival during exposure to , indicating that these genes play a role in host defense. Notably, box C/D snoRNPs complex that we previously identified as an activator of ESRE, is required for upregulation of fatty acid metabolism under ESRE-activating conditions. Our results provide insight into a novel interplay between box C/D snoRNPs, lipids, and MDT-15/Mediator in the regulation of mitochondrial surveillance and innate immunity.
多细胞生物不断面临着威胁其体内平衡的生物和非生物应激源。为了应对这一情况,它们进化出了一系列保守的防御网络,这些网络监测细胞器功能以及异常分子信号的积累。由于线粒体功能障碍可导致多种病理状况,包括代谢损伤、神经退行性变、心血管疾病、癌症以及对细菌感染的易感性,了解这些线粒体监测途径至关重要。我们实验室之前的研究表明,其中一条途径,即乙醇应激和反应元件(ESRE),会被多种应激激活,包括暴露于革兰氏阴性的机会性人类病原体。在本报告中,我们表明MDT-15及其下游效应物脂肪酸去饱和酶FAT-6和FAT-7是ESRE激活所必需的。有趣的是,从“PUFA途径”补充FAT-6/FAT-7活性下游的脂肪酸,可挽救其敲低时的ESRE激活。此外,通过RNA干扰破坏 或其下游效应物 会降低线虫在暴露于 期间的存活率,表明这些基因在宿主防御中发挥作用。值得注意的是,我们之前鉴定为ESRE激活剂的盒C/D小核仁核糖核蛋白复合物(box C/D snoRNPs complex),在ESRE激活条件下脂肪酸代谢上调中是必需的。我们的结果为盒C/D小核仁核糖核蛋白、脂质和MDT-15/中介体在调节线粒体监测和先天免疫中的新型相互作用提供了见解。