硫化氢在臭氧诱导的小鼠氧化应激模型中的作用机制

发布时间：2018-08-05 16:39

【摘要】：背景与目的急性臭氧暴露可导致气道炎症,气道上皮细胞损伤,氧化应激和气道高反应性(Airway hyperresponsiveness,AHR)。硫化氢(Hydrogen sulfide,H2S)作为新发现的气体信号分子,在炎症反应和氧化应激反应中具有重要作用。内源性H2S主要由胱硫醚-β-合成酶(Cystathionine-β-synthase,CBS)和胱硫醚-γ-裂解酶(Cystathionine-γ-yase,CSE)催化产生。本研究的目的是探讨H2S能否预防急性臭氧暴露的危害。研究方法小鼠随机分为空气暴露组和臭氧暴露组。臭氧暴露浓度为3ppm,持续3小时。每次暴露前给予小鼠腹腔注射硫氢化钠(Na HS,H2S供体)或炔丙基甘氨酸(PPG,H2S生成酶CSE抑制剂)。对照组给予磷酸盐缓冲液(PBS)。暴露结束24小时后进行研究。在另一个体外实验中,通过膜片钳技术观察Na HS对小鼠气道平滑肌细胞大电导钙激活钾通道(Large-conductance calcium activated K+channels,BKCa)的作用。结果急性臭氧暴露下调H2S/CSE、CBS体系,降低血清H2S水平和CBS、CSE m RNA及蛋白的表达。给予外源性H2S供体Na HS可抑制臭氧诱导的AHR和气道炎症,降低氧化应激水平,减少气道上皮细胞凋亡,抑制H2S/CSE、CBS体系的下调。不仅如此,Na HS可抑制臭氧诱导的p38丝裂原活化蛋白激酶(p38 MAPK)和热休克蛋白27(HSP27)的磷酸化,但Na HS可促进Akt(亦被称为蛋白激酶B)的磷酸化。给予H2S生成酶CSE抑制剂PPG将减少内源性H2S水平,并导致臭氧对肺组织的损伤进一步恶化。体外实验显示Na HS可增加小鼠气道平滑肌细胞Ca2+依赖性外向钾电流。结论本研究结果表明,H2S在臭氧诱导的氧化应激模型中具有保护作用。这种保护作用与H2S抑制p38 MAPK和HSP27的磷酸化,以及激活Akt的磷酸化有关。此外,H2S可激活小鼠气道平滑肌细胞的BKCa通道。H2S可望成为气道炎症性疾病新的治疗手段。
[Abstract]:Background & objective Acute ozone exposure can lead to airway inflammation, airway epithelial cell injury, oxidative stress and Airway hyperresponsiveness (AHR). As a newly discovered gas signal molecule, hydrogen sulfide (Hydrogen sulfide H2S) plays an important role in inflammatory reaction and oxidative stress reaction. Endogenous H 2S is mainly produced by Cystathionine- 尾 -synthase (CBS) and cystathionine- 纬 -lyase (CSE). The purpose of this study was to investigate whether H 2S can prevent acute ozone exposure. Methods mice were randomly divided into air exposure group and ozone exposure group. The ozone exposure concentration was 3 ppm and lasted for 3 hours. Mice were given intraperitoneal injection of sodium sulphide (NaHSH _ 2S donor) or propargyl glycine (CSE inhibitor) before each exposure. The control group was given phosphate buffer solution (PBS). The study was conducted 24 hours after exposure. In another experiment in vitro, the effects of NaHS on Large-conductance calcium activated K channels activated potassium channels (BK Ca) in mouse airway smooth muscle cells were observed by patch clamp technique. Results Acute ozone exposure down-regulated the CBS system of H _ 2S / CSE, decreased serum H _ 2S level and the expression of CSE m RNA and protein in serum. Exogenous H 2S donor NaHS inhibited ozone induced AHR and airway inflammation, decreased oxidative stress, reduced airway epithelial cell apoptosis, and inhibited the downregulation of H 2S / CSE / CBS system. Moreover, NaHS inhibited the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and heat shock protein 27 (HSP27) induced by ozone, but NaHS promoted the phosphorylation of Akt (also known as protein kinase B). Administration of CSE inhibitor of H2S-producing enzyme PPG could reduce endogenous H2S level and lead to further deterioration of ozone damage to lung tissue. In vitro experiments showed that NaHS could increase Ca2 dependent outward potassium currents in mouse airway smooth muscle cells. Conclusion the results suggest that H2S has protective effect on oxidative stress induced by ozone. This protective effect is related to the inhibition of phosphorylation of p38 MAPK and HSP27 and activation of phosphorylation of Akt by H 2S. In addition, H2S can activate the BKCa channel of mouse airway smooth muscle cells. H2S may be a new therapy for airway inflammatory diseases.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R-332;R56

【参考文献】