Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, 142290 Pushchino, Russia.
Department of Biochemistry, Cell Biology and Microbiology, Mari State University, pl. Lenina 1, 424001 Yoshkar-Ola, Russia.
Biomolecules. 2024 Sep 15;14(9):1159. doi: 10.3390/biom14091159.
Hyperlipidemia is a major risk factor for vascular lesions in diabetes mellitus and other metabolic disorders, although its basis remains poorly understood. One of the key pathogenetic events in this condition is mitochondrial dysfunction associated with the opening of the mitochondrial permeability transition (MPT) pore, a drop in the membrane potential, and ROS overproduction. Here, we investigated the effects of bongkrekic acid and carboxyatractyloside, a potent blocker and activator of the MPT pore opening, respectively, acting through direct interaction with the adenine nucleotide translocator, on the progression of mitochondrial dysfunction in mouse primary lung endothelial cells exposed to elevated levels of palmitic acid. Palmitate treatment (0.75 mM palmitate/BSA for 6 days) resulted in an 80% decrease in the viability index of endothelial cells, which was accompanied by mitochondrial depolarization, ROS hyperproduction, and increased colocalization of mitochondria with lysosomes. Bongkrekic acid (25 µM) attenuated palmitate-induced lipotoxicity and all the signs of mitochondrial damage, including increased spontaneous formation of the MPT pore. In contrast, carboxyatractyloside (10 μM) stimulated cell death and failed to prevent the progression of mitochondrial dysfunction under hyperlipidemic stress conditions. Silencing of gene expression of the predominate isoform ANT2, similar to the action of carboxyatractyloside, led to increased ROS generation and cell death under conditions of palmitate-induced lipotoxicity in a stably transfected HEK293T cell line. Altogether, these results suggest that targeted manipulation of the permeability transition pore through inhibition of ANT may represent an alternative approach to alleviate mitochondrial dysfunction and cell death in cell culture models of fatty acid overload.
高脂血症是糖尿病和其他代谢紊乱血管病变的一个主要危险因素，尽管其基础仍知之甚少。在这种情况下，一个关键的发病机制事件是与线粒体通透性转换（MPT）孔开放、膜电位下降和 ROS 过度产生相关的线粒体功能障碍。在这里，我们研究了分别通过与腺嘌呤核苷酸转运蛋白直接相互作用而作为 MPT 孔开放的有效抑制剂和激活剂的博克酮酸和羧基阿托力霉素对暴露于高浓度棕榈酸的小鼠原代肺内皮细胞中线粒体功能障碍进展的影响。棕榈酸盐处理（0.75 mM 棕榈酸盐/BSA 处理 6 天）导致内皮细胞活力指数下降 80%，同时伴有线粒体去极化、ROS 过度产生以及线粒体与溶酶体的共定位增加。博克酮酸（25 µM）减弱了棕榈酸盐诱导的脂毒性和所有线粒体损伤的迹象，包括增加 MPT 孔的自发形成。相比之下，羧基阿托力霉素（10 μM）刺激细胞死亡，并且在高脂血症应激条件下未能阻止线粒体功能障碍的进展。与羧基阿托力霉素的作用相似，主要同工型 ANT2 的基因表达沉默在棕榈酸盐诱导的脂毒性条件下导致 ROS 生成和细胞死亡增加在稳定转染的 HEK293T 细胞系中。总之，这些结果表明，通过抑制 ANT 靶向操纵通透性转换孔可能代表一种减轻脂肪酸过载细胞培养模型中线粒体功能障碍和细胞死亡的替代方法。
