脱氟烷通过ERK/P~(90RSK)信号通路诱导HO-1-mRNA表达抑制缺血/再灌注损伤神经元的凋亡

目的探讨脱氟烷(desflurane)的脑保护作用及其与神经元缺血/再灌注损伤后血红素氧合酶-1(HO-1)表达的信号转导通路的关系。方法将96孔和6孔培养板上培养7d的海马神经元随机分为7组:正常培养组(C组)、缺血/再灌注组(I/R组)、缺血/再灌注+6%desflurane组(D6组)、缺血/再灌注+12%desflurane组(D12组)、缺血/再灌注+12% desflurane+tin-protoporphyrin(HO-1抑制剂)组(T组)、缺血/再灌注+12% desflurane+U-0126(ERK抑制剂)组(U组)、缺血/再灌注+12% desflurane+rapamycin(RS6K抑制剂)组(R组)。C组神经元按正常培养方法培养。I/R组神经元进行缺糖缺氧后复糖复氧处理。D6组和D12组在神经元缺糖缺氧的同时接受6%或12%desflurane麻醉。T组、U组和R组在神经元进行缺糖同时分别加入tin-protoporphyrin、U-0126或Rapamycin使其终浓度均为10μmol·L-1后同D12组处理。96孔培养板的神经元进行细胞存活力的检测。6孔培养板的神经元进行神经元纯度鉴定、神经元凋亡、HO-1-mRNA表达、磷酸化ERK1/2和P90RSK蛋白表达的检测。结果缺血/再灌注后神经元存活率降低,凋亡率增加,HO-1-mRNA的表达增加,PERK1/2和PP90RSK蛋白表达增加(vsC组,P<0.01)。D6组PERK1/2和PP90RSK蛋白表达增加,HO-1-mRNA表达增加,神经元存活率增加、神经元凋亡率降低(vsI/R组,P<0.01)。D12组PERK1/2和PP90RSK蛋白表达增加,HO-1-mRNA表达增加,神经元存活率增加、神经元凋亡率降低(vsI/R组或D6组,P<0.01或P<0.05)。T组PERK1/2和PP90RSK蛋白表达变化不明显(vsD12组,P>0.05),HO-1-mRNA表达降低,神经元存活率降低、神经元凋亡率增加(vsD12组,P<0.01)。U组PERK1/2和PP90RSK表达降低,HO-1-mRNA表达降低,神经元存活率降低、神经元凋亡率增加(vsD12组,P<0.05或P<0.01)。R组PERK1/2蛋白表达变化不明显(vsD12组,P>0.05),PP90RSK表达降低,HO-1-mRNA表达降低,神经元存活率降低,神经元凋亡率增加(vsD12组,P<0.05或P<0.01)。结论Desflurane通过ERK1/2/P90RSK信号转导通路激活HO-1,在海马神经元缺血/再灌注时抑制了神经元凋亡,保护了神经元。     

Salvianolic acid B protects human endothelial progenitor cells against oxidative stress-mediated dysfunction by modulating Akt/mTOR/4EBP1, p38 MAPK/ATF2, and ERK1/2 signaling pathways

The vascular endothelium is specifically sensitive to oxidative stress, and this is one of the mechanisms that causes widespread endothelial dysfunction in most cardiovascular diseases and disorders. Protection against reactive oxygen species (ROS)-mediated oxidative damage via antioxidant mechanisms is essential for tissue maintenance and shows therapeutic potential for patients suffering from cardiovascular and metabolic disorders. Salvianolic acid B (SalB), a natural bioactive component known from Traditional Chinese Medicine, has been reported to exert cellular protection in various types of cells. However, the underlying mechanisms involved are not fully understood. Here, we showed that SalB significantly promoted the migratory and tube formation abilities of human bone marrow derived-endothelial progenitor cells (BM-EPCs) in vitro, and substantially abrogated hydrogen peroxide (H₂O₂)-induced cell damage. SalB down-regulated Nox4 and eNOS, as well as nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase expression upon H₂O₂ induction that in turn prevents oxidative-induced endothelial dysfunction. Moreover, SalB suppressed the Bax/Bcl-xL ratio and caspase-3 activation after H₂O₂ induction. Furthermore, our results provide mechanistic evidence that activation of the mTOR/p70S6K/4EBP1 pathways is required for both SalB-mediated angiogenic and protective effects against oxidative stress-induced cell injury in BM-EPCs. Suppression of MKK3/6-p38 MAPK-ATF2 and ERK1/2 signaling pathways by SalB significantly protected BM-EPCs against cell injury caused by oxidative stress via reduction of intracellular ROS levels and apoptosis. Taken together, by providing a mechanistic insight into the modulation of redox states in BM-EPCs by SalB, we suggest that SalB has a strong potential of being a new proangiogenic and cytoprotective therapeutic agent with applications in the field of endothelial injury-mediated vascular diseases.