【摘要】 目的:通过体外实验探讨硫醚环化B螺旋肽(thioether-cyclized helix B peptide,CHBP)对肾小管上皮细胞的保护作用及机制。方法:体外培养人近端肾小管上皮细胞(human renal proximal tubular cell line,HK-2)并分为Control组、H2O2组和CHBP组。H2O2组和CHBP组均通过500μmol/L H2O2刺激4 h建立氧化应激损伤模型。CHBP组在建立氧化应激损伤模型1 h前加入20 nmol/L的CHBP。500μmol/L H2O2刺激4 h后,检测细胞的活性、凋亡情况以及氧化应激损伤程度。采用Western blotting和PCR技术检测连接免疫球蛋白(binding immunoglobulin protein,BiP)、C/EBP同源蛋白(C/EBP homologous protein,CHOP)以及下游NFE2相关因子2(NF-E2-related factor 2,Nrf2)信号通路中的分子表达水平,判断内质网应激水平。结果:CHBP预处理可以减轻氧化应激导致的细胞毒性损伤;CCK-8试剂盒和原位末端标记法(TUNEL)检测发现,CHBP预处理后细胞活性增加,凋亡减少,氧化应激和内质网应激水平下降。CHBP组Nrf2和血红素氧合酶1(heme oxygenase-1,HO-1)水平较H2O2组显著升高。结论:CHBP预处理可以减轻HK-2细胞的氧化应激损伤,这一保护作用可能是通过抑制内质网应激和激活下游Nrf2信号通路实现的。更多还原

【Abstract】 Objective:To explore the protective effect of thioether-cyclized helix B peptide(CHBP)on renal tubular epithelial cells and its mechanism by experiment in vitro.Methods:Human renal proximal tubular epithelial cell line HK-2 cells were cultured in vitro and divided into control group,H2O2 group and CHBP group.Oxidative stress damage models were established by stimulation with 500μmol/L H2O2 for 4 h.In CHBP group,20 nmol/L CHBP was added to the culture medium1 h prior to the establishment of oxidative stress model.After 4 h stimulation with500μmol/L H2O2,cell viability,situation of apoptosis,and severity of oxidative stress damage were measured.The expressions of Binding immunoglobulin protein(BiP),C/EBP homologous protein(CHOP),and the molecular in downstream NF-E2-related factor 2(Nrf2)signaling pathway were detected by Western blotting and real-time PCR analysis,so as to evaluate the level of endoplasmic reticulum(ER)stress.Results:Oxidative stress induced cytotoxic injury could be alleviated by CHBP pretreatment.Kit-8(CCK-8)assay and TUNEL showed that,after CHBP pretreatment,cell viability increased,while cell apoptosis,oxidative stress and ER stress decreased.The levels of Nrf2 and heme oxygenase-1(HO-1)were significantly higher in CHBP group than those in H2O2 group.Conclusions:CHBP pretreatment could alleviate oxidative stress damage of HK-2 cells,and the protective effect may be achieved by inhibiting ER stress and activating downstream Nrf2 signaling pathway.更多还原