PBX1 attenuates MeHg-induced apoptosis by reducing ROS accumulation, mitigating double-strand DNA breaks, and enhancing homologous recombination DNA repair in SH-SY5Y cells

Given the critical role of PBX1 in maintaining genomic stability and the well-documented DNA damage effects of methylmercury (MeHg) in SH-SY5Y cells, we hypothesize that PBX1 overexpression may alleviate MeHg-induced ROS accumulation, DNA damage, and apoptosis in SH-SY5Y cells by enhancing the homologous recombination (HR) repair pathway. To test this hypothesis, we generated PBX1-overexpressing cells via lentiviral packaging. Cell viability was assessed using MTT assay, while ROS levels and apoptosis were measured by flow cytometry. DNA damage was evaluated through comet assay, and the binding of PBX1 to the BRCA1 promoter region was examined using dual-luciferase reporter assay. The expression of damage repair and apoptosis-related proteins was detected by Western blotting.

鉴于PBX1在维持基因组稳定性中的关键作用，以及甲基汞（methylmercury, MeHg）在SH-SY5Y细胞中已被证实的DNA损伤效应，本研究提出假设：PBX1过表达可通过增强同源重组（homologous recombination, HR）修复通路，缓解甲基汞诱导的SH-SY5Y细胞活性氧（reactive oxygen species, ROS）积累、DNA损伤与细胞凋亡。为验证该假设，本研究通过慢病毒包装技术构建了PBX1过表达细胞模型。采用MTT法检测细胞活力，通过流式细胞术测定活性氧水平与细胞凋亡率，利用彗星实验评估DNA损伤程度，采用双荧光素酶报告基因实验检测PBX1与BRCA1启动子区域的结合情况，最后通过蛋白质印迹（Western blotting）检测损伤修复及凋亡相关蛋白的表达水平。