Abstract：
In this study, A549/PQ cells with moderate resistance to paraquat (PQ) were obtained by treating A549 cells with PQ, their growth rate was slowed down, the accumulation concentration of PQ and the levels of growth inhibition, injury and early apoptosis induced by PQ were significantly lower than those of parental A549 cells. Microarray screening and RT-qPCR detection found that Synaptotagmin-1 (SYT1) expression in drug-resistant cells was significantly increased, and PQ further enhanced its expression. After inhibiting SYT1 expression in A549/PQ cells, cell viability, intracellular PQ concentration and the expression of Bcl-2, SNAP25 and RAB26 were significantly reduced, while the mortality, early apoptosis rate and Bax expression were significantly increased. In vivo experiments also further showed that PQ promoted the expression of SYT1, SNAP25 and RAB26 in PQ-poisoned mice; when inhibiting SYT1 expression, PQ concentration in lung tissues was significantly increased, and the levels of lung injury and apoptosis were also significantly enhanced, while the expression of SNAP25 and RAB26 was significantly reduced. This indicates that PQ poisoning leads to compensatory up-regulation of vesicle transport related proteins such as SYT1 in vivo, thereby promoting PQ transmembrane transport, and then reducing the pulmonary accumulation of PQ and PQ-caused lung injury.
摘要：
在这项研究中,用PQ处理A549细胞,获得对百草枯(PQ)有中等抗性的A549/PQ细胞,他们的增长速度放缓了，PQ的积累浓度和生长抑制水平，PQ诱导的损伤和早期凋亡显著低于亲本A549细胞。基因芯片筛选和RT-qPCR检测发现,耐药细胞中Synaptotagmin-1(SYT1)的表达显著增加,和PQ进一步增强其表达。在A549/PQ细胞中抑制SYT1表达后，细胞活力，细胞内PQ浓度和Bcl-2、SNAP25和RAB26的表达显著降低,而死亡率，早期细胞凋亡率和Bax表达显著升高。体内实验还进一步表明，PQ促进PQ中毒小鼠SYT1、SNAP25和RAB26的表达；当抑制SYT1表达时，肺组织中PQ浓度显著增高，肺损伤和细胞凋亡水平也显著增强，而SNAP25和RAB26的表达显著降低。这表明PQ中毒导致囊泡转运相关蛋白如SYT1在体内的代偿性上调,从而促进PQ跨膜运输，然后减少PQ的肺积累和PQ引起的肺损伤。
