Gambhir Lokesh
Department of Life Sciences, Shri Guru Ram Rai Institute of Technology & Sciences.
Drug Discov Ther. 2016;10(2):93-102. doi: 10.5582/ddt.2016.01028. Epub 2016 Apr 13.
Detrimental effects of ionizing radiation (IR) are observed at the doses above 1 Gy. Treatment modalities are available up to doses of 6 Gy including bonemarrow transplantation and administration of antibiotics. However, exposure to IR doses above 8 Gy results in gastro-intestinal (GI) syndrome characterised by denudated villi, apoptosis of crypt cells and elevated inflammatory responses. Multiple strategies have been employed to investigate novel agents to protect against IR induced injury. Since cellular redox homeostasis plays a pivotal role in deciding the cell fate, present study was undertaken to explore the potential of 1,4-naphthoquinone (NQ), a pro-oxidant, to ameliorate IR induced GI syndrome. NQ protected INT 407 cells against IR induced cell death of intestinal epithelial cells in vitro. NQ induced perturbation in cellular redox status and induced the activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway. Thiol antioxidant and inhibitors of Nrf2 pathway abrogated the radioprotection offered by NQ. Further, knocking down Nrf2 rescind the NQ mediated protection against IR induced cell death. In conclusion, NQ protects against IR radiation induced GI syndrome in vitro by perturbing cellular redox and activating Nrf2 pathway. This is the first report highlighting the potential of a pro-oxidant to ameliorate IR induced GI injury.
在剂量高于1 Gy时可观察到电离辐射(IR)的有害影响。在剂量高达6 Gy时可采用多种治疗方式,包括骨髓移植和使用抗生素。然而,暴露于高于8 Gy的IR剂量会导致胃肠道(GI)综合征,其特征为绒毛剥脱、隐窝细胞凋亡和炎症反应加剧。人们已采用多种策略来研究新型药物以预防IR诱导的损伤。由于细胞氧化还原稳态在决定细胞命运中起关键作用,因此开展了本研究以探索促氧化剂1,4-萘醌(NQ)改善IR诱导的GI综合征的潜力。NQ在体外保护INT 407细胞免受IR诱导的肠上皮细胞死亡。NQ诱导细胞氧化还原状态紊乱并诱导核因子红细胞2相关因子2(Nrf2)途径的激活。硫醇抗氧化剂和Nrf2途径抑制剂消除了NQ提供的辐射防护作用。此外,敲低Nrf2可消除NQ介导的对IR诱导细胞死亡的保护作用。总之,NQ通过扰乱细胞氧化还原并激活Nrf2途径在体外预防IR辐射诱导的GI综合征。这是首份强调促氧化剂改善IR诱导的GI损伤潜力的报告。