中文摘要：

目的 :研究虾青素(astaxanthin,AST)对过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptor gamma,PPAR-γ)通路的激活作用及对脂多糖/干扰素-γ(lipopolysaccharide/interferon gamma,LPS/IFN-γ)诱导C6细胞炎症反应的影响。方法:应用Western Blot、实时定量PCR技术检测不同浓度AST对PPAR-γ表达的影响;采用C6细胞炎症刺激模型,通过实时定量聚合酶链反应(polymerase chain reaction,PCR)检测AST对诱导型一氧化氮合酶(inducible nitric oxide synthase,i NOS)m RNA表达的影响;利用Western Blot检测AST对i NOS蛋白表达的影响;利用总一氧化氮(nitric oxide,NO)试剂盒检测AST对NO释放的影响;通过PPAR-γ的选择性抑制剂GW9662探讨AST的抗炎作用与PPAR-γ的相关性;采用免疫荧光标记研究AST对核转录因子kappa B(nuclear transcription factor-kappa B,NF-κB)p65亚基核转位的影响;构建NF-κB质粒,双荧光素酶报告基因法研究AST对NF-κB转录激活的影响。结果:AST以剂量依赖和时间依赖性方式上调C6细胞中PPAR-γm RNA和蛋白水平;AST对LPS/IFN-γ所诱导的C6细胞炎症反应有明显的抑制作用,表现为抑制p65核转位和NF-κB的转录激活,下调i NOS的表达,减少NO的释放,而且这种抑制作用与PPAR-γ相关。结论:AST是一种新的PPAR-γ激动剂,对炎症反应的抑制作用与激活PPAR-γ通路有关。

英文摘要：

Objective: To investigate the effect of astaxanthin(AST) on peroxisome proliferator activated receptor gamma ( PPAR-γ) pathway and on interferon gamma/lipopolysaccharide(IFN-γ/LPS)-induced inflammatory responses in C6 cells. Methods: The expression of PPAR-γ was detected by Western Blot and real time-polymerase chain reaction(PCR) after C6 cells were treated with different concentration of AST. C6 cells were pretreated with AST and subsequently incubated with IFN-γ/LPS. The level of NO was detected by total nitric oxide assay kit, iNOS mRNA and protein expression were measured by real time-PCR and Western Blot respectively. P65 nuclear translocation was observed by immunocytochemistry. Moreover, the transcriptional activity of NF-κB was analyzed by luciferase assay. GW9662, a PPAR-γ antagonist, was used to explore the correlation between anti-inflammatory effects of AST and PPAR-γ. Results:Treatment of C6 cells with AST increased the expression of PPAR-γ in a dose- and time-dependent manner. Furthermore, AST inhibited LPS/IFN-γ-induced iNOS expression, NO production, p65 nuclear translocation and transcriptional activity of NF-κB. The inhibitory effects of AST on LPS/IFN-γ-induced inflammatory responses in C6 cells were blocked by GW9662, a PPAR-γ antagonist. These results suggested that AST exhibited anti-inflammatory effects on C6 cells induced by IFN-γ/LPS which involved the activation of PPAR-γpathway. Conclusion:AST is a novel PPAR-γagonist,which is associated with its anti-inflammatory effects.