小檗碱干预脂多糖诱导小鼠肺泡巨噬细胞MH-S 分泌NO、IL-6 等炎性 介质的机制研究

目的:观察小檗碱对脂多糖(LPS)诱导小鼠肺泡巨噬细胞分泌炎性介质的影响,并探讨其可能的机制。方法:体外培养小鼠肺泡巨噬细胞MH-S,用终浓度为0.5μg/ml的LPS刺激后,加入不同浓度的小檗碱作用24 h。MTT法检测小檗碱对MH-S活力的影响;采用NO测定试剂盒检测NO的含量,ELISA和RT-PCR法检测TNF-α、IL-6、IL-1及IL-12的蛋白和mRNA水平;Western blot法检测MH-S细胞中iNOS、TLR4、MyD88、IRAK-4及NF-κB p65的水平。结果:小檗碱在浓度不超过5μmol/L时,在24 h内对MH-S细胞的活力几乎无影响,在10μmol/L的浓度下对巨噬细胞的活力有抑制作用,并呈一定的时-效性。小檗碱能够显著降低MH-S细胞中NO的分泌量(P0.05),并在蛋白和基因层面上剂量依赖性地降低TNF-α、IL-6、IL-1及IL-12的水平。小檗碱能够显著下调iNOS、TLR4、MyD88、IRAK-4及NF-κB p65的表达量(P0.05)。结论:小檗碱能够抑制iNOS的活性,从而减少NO的分泌,同时通过抑制TLR4/MyD88/IRAK-4通路而抑制NF-κB的激活,进而发挥抗炎作用。     

DEN2对鼠源性DC TLR7、MyD88、NF-κB的表达与细胞因子分泌的影响

目的:观察登革2型病毒(DEN2)感染鼠源性DC后TLR7、MyD88、NF-κB的表达及IFN-α、IP-10的分泌变化,探讨MyD88依赖型信号通路在DEN2感染中的作用.方法:rmGM-CSF和rmIL-4联合诱导C57BL/6小鼠骨髓源性树突状细胞(BMDC),常规方法增殖鉴定DEN2,利用DEN2(MOI =0.4)感染BMDC,直接免疫荧光检测DEN2吸附鼠源性BMDC:Western blot检测感染后不同时间TLR7、MyD88、NF-κB蛋白表达.双抗体夹心ELISA法检测感染后不同时间细胞培养上清IP-10、IFN-α的水平,RT-PCR检测相应时间点被感染DC内DEN2 NS5核酸水平.结果:rmGM-CSF和rmIL-4联合诱导C57BL/6小鼠BMDC,5天后获得纯度为70％的相对未成熟DC;与对照组相比DEN2感染BMDC后24小时TLR7、MyD88、NF-κB的表达升高;48小时TLR7表达低于正常对照组,但MyD88、NF-κB的表达高于正常对照组;72小时DEN2感染组TLR7、MyD88、NF-κB的表达均较前降低,且TLR7、MyD88的表达低于正常对照组.DEN2感染组细胞培养上清IFN-α、IP-10的水平明显高于正常对照组,IFN-α逐渐升高,72小时分泌量达最高,可分泌(933.94 ±29.02) pg/ml; IP-10在48小时分泌达高峰,分泌量为(834.44 ±43.60) pg/ml,结果具有统计学意义(P＜0.05),且被感染DC内DEN2 NS5病毒核酸水平48小时达最高,72小时有所降低.结论:DEN2可影响小鼠BMDC TLR7、MyD88、NF-κB的表达,促进其分泌IFN-α、IP-10进而影响病毒复制.     

川芎嗪抑制TLR4/MyD88/NF-κB信号通路减轻子宫内膜异位症大鼠炎症反应北大核心CSCD

目的探讨川芎嗪抑制Toll样受体4(TLR4)/髓样分化因子88(MyD88)/核因子κB(NF-κB)信号通路减轻子宫内膜异位症(EMs)大鼠炎症反应的作用。方法自体子宫移植法构建EMs大鼠模型,随机分为EMs组、川芎嗪(低、中、高)剂量组、阳性药物组,每组各12只;进行假手术的12只大鼠作为假手术组。游标卡尺测定异位病灶体积,HE染色检测异位内膜组织病理学改变,ELISA检测血清性激素及炎症因子水平,qRT-PCR、Western blot、免疫荧光染色分别检测异位内膜组织中炎症因子mRNA表达、TLR4/MyD88/NF-κB信号通路相关蛋白表达及NF-κB p65入核情况。结果与假手术组比较,EMs组大鼠异位内膜组织出现明显病理损伤,血清雌二醇(E2)、孕激素(P)含量、肿瘤坏死因子-α(TNF-α)、白介素(IL)-1β、IL-6水平及异位内膜组织中TNF-α、IL-1β、IL-6 mRNA、总蛋白TLR4、MyD88、p-NF-κB p65和核蛋白NF-κB p65表达水平升高,血清促卵泡激素(FSH)、促黄体生成素(LH)含量降低(P<0.05),同时NF-κB p65蛋白大量入核;与EMs组比较,川芎嗪(低、中、高)剂量组和阳性药物组可缓解EMs模型大鼠的上述改变并降低异位病灶体积,且川芎嗪高剂量组和阳性药物组对EMs大鼠的作用效果较好且相近。结论川芎嗪可能通过抑制TLR4/MyD88/NF-κB信号通路激活减轻EMs大鼠炎症反应。     

贞芪扶正胶囊介导TLR4/MyD88/NF-κB信号通路抑制慢性湿疹小鼠炎症反应

目的 探讨贞芪扶正胶囊对慢性湿疹小鼠炎症反应的抑制作用.方法 SPF级C57BL/6小鼠30只,按随机数字表法随机分为对照组(control组)、模型组(CAD组)与贞芪扶正胶囊组(ZQFZ组).观察各组小鼠双耳肿胀程度、双耳变应评分;HE染色观察病灶处皮肤病理学变化;ELISA法检测血清炎性因子TNF-α、IL-6及IL-1β水平;RT-PCR检测皮肤中TNF-α、IL-6及IL-1β mRNA表达;Western blot检测TLR4、MyD88及NF-κB蛋白表达;RT-PCR检测皮肤中TLR4、MyD88及NF-κB mRNA表达.结果 ZQFZ可以显著改善小鼠双耳肿胀程度,降低小鼠双耳变应评分(P＜0.05);减轻小鼠皮肤炎症浸润并降低血浆及皮肤中TNF-α、IL-6及IL-1β蛋白与mRNA表达(P＜0.05);同时ZQFZ还可显著下调小鼠皮肤组织中TLR4、MyD88、NF-κB蛋白与mRNA表达(P＜0.05).结论 贞芪扶正胶囊可以通过抑制炎性反应达到治疗慢性湿疹作用,其作用机制可能与其调控TLR4/MyD88/NF-κB信号通路有关.     

干扰素-γ水平影响系统性红斑狼疮小鼠体TLR9/MyD88/NF-κB p65信号通路的初步研究

目的 探究干扰素-γ(IFN-γ)水平对系统性红斑狼疮(SLE)小鼠体内Toll样受体9/髓样分化因子88/核因子κB亚基p65(TLR9/MyD88/NF-κB p65)信号通路的影响.方法 将30只SLE MRL/lpr小鼠随机分为模型组、空质粒组和IFN-γ siRNA组,空质粒组和IFN-γsiRNA组采用活体电转染技术分别转入空质粒、IFN-γsiRNA质粒,并鉴定转染后SLE小鼠外周血IFN-γγ的表达;另取10只C57BL/6小鼠作为正常组,ELISA检测IL-6、TNF-α和自身抗体[抗双链DNA(ds-DNA)抗体、抗组蛋白抗体(IgM)]水平,观察各组小鼠肾组织病理变化及肾功能情况[血清肌酐(SCr)、尿素氮(BUN)],Western blot检测肾组织中TLR9、MyD88、NF-κB p65蛋白表达.结果 与正常组比较,模型组血清IFN-γγ、 IL-6、TNF-α、抗ds-DNA抗体、抗IgM抗体、SCr、BUN、肾组织TLR9、MyD88、NF-κB p65磷酸化水平显著升高(P＜0.05);与模型组比较,IFN-γsiRNA组IFN-γγ、IL-6、TNF-α、抗ds-DNA抗体、抗IgM抗体、SCr、BUN、肾组织TLR9、MyD88、NF-κB p65磷酸化水平显著降低(P＜0.05);但空质粒组与模型组上述指标的比较,差异无统计学意义(P＞0.05).结论 转染IFN-γγsiRNA质粒后,可减轻SLE小鼠炎症反应与肾损伤,可能与抑制TLR9/MyD88/NF-κB p65信号通路有关.     

栀子苷抑制甲型流感病毒感染细胞中Toll样受体7/核因子-κB信号通路

目的 研究栀子苷对甲型流感病毒H3N2感染所致的Toll样受体7(Toll-like receptors7,TLR7)及其介导的细胞内转录因子核因子-κB(nuclear factor-kappa B,NF-κB)活性及前炎症细胞因子TNF-α和IL-6释放的影响,以探讨栀子苷干预甲型流感病毒作用的分子生物学机制.方法 甲型流感病毒H3N2作为刺激因素,利用双荧光素酶顺式报告系统和免疫荧光实验检测栀子苷对NF-κB转录活性及NF-κB核转位的影响.RT-PCR法进一步验证栀子苷对NF-κB上下游靶基因TLR7、TNF-α和IL-6 mRNA表达水平的影响.结果 通过NF-κB双萤光素酶报告系统检测发现,与正常对照组比较,病毒感染的细胞中NF-κB荧光素酶报告活性明显升高;与病毒损伤组比较,栀子苷治疗组NF-κB荧光素酶报告活性明显受到抑制.荧光倒置显微镜下观察NF-κB p65磷酸化水平及核转位变化结果显示,病毒感染的细胞中NF-κB磷酸化水平及人核率明显升高;与病毒损伤组比较,栀子苷治疗组NF-κB磷酸化水平及入核率明显受到抑制.RT-PCR结果显示栀子苷能明显抑制病毒诱导的TLR7、TNF-α和IL-6 mRNA的高表达.结论 栀子苷可拮抗甲型流感病毒H3N2感染细胞中TLR7介导的细胞内转录因子NF-κB信号转导通路的活化,并可抑制其下游靶基因TNF-α和IL-6 mRNA的高表达水平来发挥抗病毒感染的作用.     

生殖支原体脂质相关膜蛋白诱导宫颈上皮细胞表达人β防御素2

目的观察生殖支原体脂质相关膜蛋白(LAMP)能否诱导宫颈上皮细胞表达人β防御素2(hBD-2),并探讨其可能的调控机制。方法体外培养End1/E6E7人宫颈上皮细胞,用不同浓度的LAMP作用细胞48 h,反转录PCR检测hBD-2 mRNA的表达,Western blot法检测hBD-2蛋白的表达;用Toll样受体2(TLR2)和TLR6中和抗体孵育End1/E6E7细胞,并用TLR2、TLR6和MyD88负显性突变体转染细胞,以明确TLR2、TLR6和MyD88在介导hBD-2表达中的作用;Western blot法检测核因子κB(NF-κB)p65亚基核转位情况,电泳迁移率实验(EMSA)分析LAMP处理前后NF-κB的DNA结合活性;采用NF-κB抑制剂二硫代氨基甲酸吡咯烷(PDTC)处理,观察对hBD-2表达的影响。结果生殖支原体LAMP可诱导End1/E6E7细胞表达hBD-2mRNA和蛋白。TLR2和TLR6中和抗体以及其负显性突变体转染后,能降低hBD-2表达;MyD88负显性突变体也能显著抑制LAMP诱导的hBD-2表达。Western blot结果显示,LAMP处理后可诱导p65核转位,并能增强NF-κB的DNA结合活性。而NF-κB抑制剂PDTC处理后,hBD-2表达降低。结论生殖支原体LAMP可诱导End1/E6E7细胞表达hBD-2,可能受TLR2、TLR6/MyD88/NF-κB调控。     

生殖支原体脂质相关膜蛋白诱导宫颈上皮细胞表达人β防御素2北大核心CSCD

目的观察生殖支原体脂质相关膜蛋白(LAMP)能否诱导宫颈上皮细胞表达人β防御素2(hBD-2),并探讨其可能的调控机制。方法体外培养End1/E6E7人宫颈上皮细胞,用不同浓度的LAMP作用细胞48 h,反转录PCR检测hBD-2 mRNA的表达,Western blot法检测hBD-2蛋白的表达;用Toll样受体2(TLR2)和TLR6中和抗体孵育End1/E6E7细胞,并用TLR2、TLR6和MyD88负显性突变体转染细胞,以明确TLR2、TLR6和MyD88在介导hBD-2表达中的作用;Western blot法检测核因子κB(NF-κB)p65亚基核转位情况,电泳迁移率实验(EMSA)分析LAMP处理前后NF-κB的DNA结合活性;采用NF-κB抑制剂二硫代氨基甲酸吡咯烷(PDTC)处理,观察对hBD-2表达的影响。结果生殖支原体LAMP可诱导End1/E6E7细胞表达hBD-2mRNA和蛋白。TLR2和TLR6中和抗体以及其负显性突变体转染后,能降低hBD-2表达;MyD88负显性突变体也能显著抑制LAMP诱导的hBD-2表达。Western blot结果显示,LAMP处理后可诱导p65核转位,并能增强NF-κB的DNA结合活性。而NF-κB抑制剂PDTC处理后,hBD-2表达降低。结论生殖支原体LAMP可诱导End1/E6E7细胞表达hBD-2,可能受TLR2、TLR6/MyD88/NF-κB调控。     

山柰酚通过下调NF-κB信号通路减轻猪源甲型H9N2流感病毒所致小鼠急性肺损伤

目的:探讨山柰酚是否通过下调转录因子NF-κB信号通路的表达而保护感染猪源甲型H9N2流感病毒引起急性肺损伤的小鼠。方法:猪源甲型H9N2流感病毒感染BALB/c小鼠建立急性肺损伤模型,山柰酚干预后检测肺湿重与干重比,观察肺组织的病理学变化,检测支气管肺泡灌洗液内炎性细胞数量以及肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)和白细胞介素1β(IL-1β)含量同时检测肺组织匀浆中超氧化物歧化酶(SOD)和髓过氧化物酶(MPO)活性以及丙二醛(MDA)含量,Western blot检测小鼠肺内NF-κB P65的表达,ELISA检测小鼠肺组织匀浆细胞核提取物中NF-κB P65和NF-κB P50的核转位。结果:山柰酚能降低小鼠死亡率,改善肺组织的病理学变化和肺水肿程度,并能降低肺内巨噬细胞、淋巴细胞和中性粒细胞等炎性细胞的数量同时降低TNF-α、IL-6、IL-1β和MDA的含量,抑制MPO的活性并升高SOD的活性。另外,山柰酚可以下调NF-κB P65的表达增加细胞核提取物中NF-κB P65和NF-κB P50的核转位。结论:山柰酚通过下调NF-κB信号通路的表达从而降低猪源甲型H9N2流感病毒所致急性肺损伤小鼠的炎症程度和氧化应激损伤,最终减轻流感病毒所致的急性肺损伤。     

甘草酸对LPS 诱导的IEC-6 细胞NF-κB 通路及炎症因子表达的影响

目的:研究甘草酸(GA)对脂多糖(LPS)诱导肠上皮细胞IEC-6发生炎症应激的影响,并进一步探讨其炎症调控的作用机制。方法:以IEC-6细胞株为研究对象,实验分Control组、LPS模型组、LPS+GA组、GA组,Western blot法检测TLR4、CD14、MyD88、IκBα、p-IκBα、NF-κB p65表达变化; RT-qPCR和Western blot检测下游炎症基因的mRNA水平及蛋白表达。结果:与Control组相比,LPS诱导后IEC-6细胞中TLR4、CD14、MyD88的蛋白表达水平上调,IκBα的磷酸化水平显著升高及NF-κB p65的核转位增加(P0. 05),同时上调ICAM-1、COX-2、i NOS和IL-6炎症相关基因表达,并减少IL-10表达(P0. 05),甘草酸干预后可显著逆转上述改变,结果均具有统计学意义(P0. 05)。结论:甘草酸能抑制LPS活化的TLR4/NF-κB信号通路,进而下调LPS诱导的促炎基因表达,减轻肠上皮细胞的炎症性损伤。     

Effect of chlorogenic acid on LPS-induced proinflammatory signaling in hepatic stellate cells

Objective and design

This study was aimed at investigating the effect of chlorogenic acid (CGA) on lipopolysaccharide (LPS)-induced proinflammatory signaling in hepatic stellate cells (HSCs).

Methods

An immortalized rat HSC line was cultured in vitro and treated with LPS in the absence or presence of CGA. Reactive oxygen species (ROS) production in the HSCs was monitored by flow cytometer using DCFH-DA. The protein expression levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB), and p-IκB-α were determined by Western blot. The mRNA expression levels of TLR4, MyD88, monocyte chemotactic protein 1(MCP-1), and interleukin 6 (IL-6) were detected by RT-PCR. The levels of MCP-1 and IL-6 in the culture supernatant of HSCs were measured by ELISA.

Results

CGA had no effect on expression of TLR4 and MyD88. However, the treatment of CGA can inhibit LPS-induced production of ROS in HSCs. Meanwhile, CGA can inhibit LPS-induced nuclear translocation of NF-κB and IκB-α phosphorylation in HSCs, as well as NAC (a ROS scavenger). The mRNA expression and the levels of MCP-1 and IL-6 in the culture supernatant of the HSCs in this study were elevated by LPS stimulation and inhibited by CGA treatment, as well as NAC and PDTC (a NF-κB inhibitor).

Conclusion

Our results indicate that CGA can efficiently inhibit LPS-induced proinflammatory responses in HSCs and the anti-inflammatory effect may be due to the inhibition of LPS/ROS/NF-κB signaling pathway.     

TLR4／NF-κB信号通路在SiO2所致矽肺模型肺泡巨噬细胞脂质代谢调控中的作用#br#

目的 探讨Toll样受体4（Toll like receptor 4,TLR4）/核转录因子κB（nuclear factor-κB,NF-κB）通路在二氧化硅（SiO2）所致大鼠矽肺模型肺泡巨噬细胞的脂质代谢中的作用。 方法 按随机数字表法将36只SD大鼠分为正常组、模型组、抑制剂组。模型组、抑制剂组采用一次性气管内缓慢滴注1 mL SiO2悬浮液进行造模。造模成功后抑制剂组大鼠每天定时耳缘静脉注射TAK-242（TLR4/NF-κB信号特异性抑制剂）,剂量为0.5 mg/kg,正常组和模型组注射等剂量生理盐水。4周后处死大鼠收集支气管灌洗液（bronchial lavage fluid,BALF）,ELISA测定各组大鼠BALF中白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）的含量;提取BALF中的肺泡巨噬细胞进行培养,油红O染色观察各组大鼠肺泡巨噬细胞的脂滴形成;Western blot检测各组肺泡巨噬细胞中TLR4、MyD88、NF-κB的表达水平。 结果 与正常组相比,模型组、抑制剂组大鼠BALF中IL-6和TNF-α的含量,巨噬细胞中油红O阳性比例,巨噬细胞中TLR4、MyD88、NF-κB的表达升高,差异具有统计学意义（均P<0.05）;与模型组相比,抑制剂组大鼠上述指标降低,差异具有统计学意义（均P<0.05）。 结论 在SiO2所致大鼠矽肺模型中,TLR4/NF-κB信号参与肺泡巨噬细胞的脂质代谢的调控,抑制该信号的表达,能明显抑制矽肺的病理损伤。     

黄芪总皂苷对脂多糖诱导的BV2小胶质细胞的抗炎机制

目的:探讨黄芪总皂苷(TAS)对脂多糖(LPS)诱导的BV2小胶质细胞炎症损伤的抗炎作用机制.方法:用CCK-8法筛选出对细胞活力无抑制的药物浓度;用浓度为1 mg/L的LPS刺激BV2细胞24 h,建立细胞炎症模型;实验分为正常组、LPS组、高剂量(75 mg/L)TAS组和低剂量(50 mg/L)TAS组;应用流式...     

MD-2 regulates LPS-induced NLRP3 inflammasome activation and IL-1beta secretion by a MyD88/NF-κB-dependent pathway in alveolar macrophages cell line

Myeloid differentiation protein 2 (MD-2) is required in the recognition of lipopolysaccharide (LPS) by toll-like receptor 4 (TLR4), and participates in LPS-induced alveolar macrophage (AM) inflammation during acute lung injury (ALI). Activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome aggravates inflammation in LPS-induced ALI. However, there is currently little known about the relationship between MD-2 signaling and the NLRP3 inflammasome. This study showed that NLRP3 expression, IL-1beta (IL-1β) secretion, and pyroptosis were up-regulated after LPS stimulation in the NR8383 AM cell-line. MD-2 gene knock-down reduced LPS-induced mRNA and protein expression of NLRP3 and IL-1β secretion in NR8383 cells, and inhibited the MyD88/NF-κB signaling pathway. Conversely, over-expression of MD-2 not only heightened NLRP3, MyD88, and NF-κB p65 protein expression, it also aggravated the LPS-induced inflammatory response. Furthermore, the NF-κB inhibitor SN50 had a beneficial role in decreasing NLRP3 and caspase-1 mRNA and protein expression. The observations suggest that MD-2 helps to regulate LPS-induced NLRP3 inflammasome activation and the inflammatory response in NR8383 cells, and likely does so by affecting MyD88/NF-κB signaling.     

TLR4-MyD88-TRAF6-TAK1 Complex-Mediated NF-κB Activation Contribute to the Anti-Inflammatory Effect of V8 in LPS-Induced Human Cervical Cancer SiHa Cells

The synthetic compound 7-4-[Bis-(2-hydroxyethyl)-amino]-butoxy-5-hydroxy-8-methoxy-2-phenylchromen-4-one (V8) is a novel flavonoid-derived compound. In this study, we investigated the effects of V8 on Toll-like receptor 4 (TLR4)-mediated inflammatory reaction in human cervical cancer SiHa cells and lipopolysaccharide (LPS)-induced TLR4 activity in cervical cancer SiHa (HPV16+) cells, but not in HeLa (HPV18+) and C33A (HPV?) cells. In addition, V8 inhibited LPS-induced expression of TLR4, MyD88, TRAF6 and phosphorylation of TAK1, and their interaction with TLR4 in SiHa cells, resulting in an inhibition of TLR4-MyD88-TRAF6-TAK1 complex. Moreover, V8 blocked LPS-induced phosphorylation of IκB and IKK, resulting in inhibition of the nuclear translocation of P65-NF-κB in SiHa cells. We also found that V8 reduced the expression of NF-κB target genes, such as those for COX-2, iNOS, IL-6, IL-8, CCL-2, and TNF-α in LPS-stimulated SiHa cells. These results suggested that V8 exerted an anti-inflammatory effect on SiHa cells by inhibiting the TLR4-MyD88-TRAF6-TAK1 complex-mediated NF-κB activation.     

Potential autocrine regulation of interleukin-33/ST2 signaling of dendritic cells in allergic inflammation

This study identified a novel phenomenon that dendritic cells (DCs) produced interleukin (IL)-33 via Toll-like receptor (TLR)-mediated innate pathway. Mouse bone marrow–derived DCs were treated with or without microbial pathogens or recombinant murine IL-33. IL-33 mRNA and protein were found to be expressed by DCs and largely induced by several microbial pathogens, highly by lipopolysaccharide (LPS) and flagellin. Using two mouse models of topical challenge by LPS and flagellin and experimental allergic conjunctivitis, IL-33-producing DCs were observed in ocular mucosal surface and the draining cervical lymph nodes in vivo. The increased expression levels of myeloid differentiation primary-response protein 88 (MyD88), nuclear factor (NF)-κB1, NF-κB2, and RelA accompanied by NF-κB p65 nuclear translocation were observed in DCs exposed to flagellin. IL-33 induction by flagellin was significantly blocked by TLR5 antibody or NF-κB inhibitor quinazoline and diminished in DCs from MyD88 knockout mice. IL-33 stimulated the expression of DC maturation markers, CD40 and CD80, and proallergic cytokines and chemokines, OX40L, IL-4, IL-5, IL-13, CCL17 (C-C motif chemokine ligand 17), TNF-α (tumor necrosis factor-α), and IL-1β. This stimulatory effect of IL-33 in DCs was significantly blocked by ST2 antibody or soluble ST2. Our findings demonstrate that DCs produce IL-33 via TLR/NF-κB signaling pathways, suggesting a molecular mechanism by which local allergic inflammatory response may be amplified by DC-produced IL-33 through potential autocrine regulation.     

黄芪甲苷通过toll样受体4/核因子κB通路介导辐射所致肾损伤的防护作用

目的 探讨黄芪甲苷（AS-Ⅳ）是否通过toll样受体4（TLR4）/核因子κB（NF-κB）介导的信号通路对辐射诱导肾脏损伤起到保护作用。 方法 将小鼠分为正常对照组、DMSO溶剂组、辐射组(IR)、IR + AS-Ⅳ 20 mg/kg 组和IR + AS-Ⅳ 40 mg/kg 组。小鼠给予AS-Ⅳ腹腔注射1个月后,以8Gy的60Coγ进行全身辐射。测定血清肌酐（Cr）和尿酸（BUA）的含量,进行肾组织HE和免疫组织化学染色,并检测肾脏TLR4/NF-κB信号通路相关蛋白的表达情况。 结果 与对照组相比,辐射组小鼠血清中Cr和BUA含量明显升高（P<0.001）,肾小球萎缩,肾小管扩张,TLR4和髓样分化因子88（MyD88）阳性表达明显增多(P<0.001),且TLR4/NF-κB信号通路相关蛋白［TLR4、MyD88、NF-κB、白细胞介素1β（IL-1β）和肿瘤坏死因子α（TNF-α）］表达极显著升高（P<0.01）;AS-Ⅳ预处理能降低血清中Cr和BUA的含量（P<0.05, P<0.01或 P<0.001）,明显改善辐射所致的病理反应,降低TLR4/NF-κB 信号通路相关蛋白的表达（P<0.05或 P<0.01）。 结论 AS-Ⅳ可能通过TLR4/NF-κB信号通路下调炎症因子的释放,从而改善辐射诱导的小鼠肾损伤,发挥保护作用。     

TNF-α诱导类风湿关节炎滑膜细胞NF-κB信号通路活化的探讨

目的研究TNF-α对类风湿关节炎(rheumatoid arthritis,RA)滑膜细胞NF-κB信号转导通路活化的影响。方法原代培养类风湿性关节炎滑膜细胞;应用Western blot检测滑膜细胞p65-NF-κB和ΙκBα蛋白的表达变化;应用免疫荧光技术分析NF-κB核移位的变化。结果 TNF-α刺激不同时间后p65-NF-κB蛋白在滑膜细胞核内表达增加,而在胞浆表达减少,30 min时最明显;同时,免疫荧光显示TNF-α可促使NF-κB向滑膜细胞核内移位;TNF-α刺激20 min后ΙκBα蛋白降解明显增加。结论TNF-α诱导类风湿关节炎滑膜细胞NF-κB信号通路活化,可能与类风湿关节炎炎症进程有关。     

TLR4、MyD88、NF-κBmRNA在实验性自身免疫性肌炎小鼠淋巴结中的表达及意义

目的:研究TLR4、MyD88、NF-κB mRNA在实验性自身免疫性肌炎小鼠淋巴结中的表达情况,探讨TLR4在肌炎发病中的作用。方法:将30只雌性BALB/c小鼠随机分为5组(每组6只):第1组为正常对照组,其它4组分别为肌炎模型1周处理组、2周处理组、3周处理组和4周处理组,后4组均应用肌球蛋白诱导实验性自身免疫性肌炎模型(EAM)。采用实时荧光定量PCR方法检测各组小鼠淋巴结TLR4、MyD88、NF-κB mRNA表达水平。结果:(1)与正常小鼠相比,肌炎各组小鼠淋巴结中TLR4、MyD88、NF-κB mRNA表达均有统计学差异,表现为不同程度升高(P<0.01),第3组升高最为显著(P<0.01),第4组较第5组升高(P<0.01);(2)各组淋巴结中TLR4 mRNA表达水平与MyD88 mRNA、NF-κBmRNA表达水平均呈正相关(r=0.906,r=0.967,P<0.01),MyD88 mRNA表达水平与NF-κB mRNA表达水平呈正相关(r=0.919,P<0.01)。结论:TLR4在自身免疫性肌炎发生发展过程中发挥重要作用,且以MyD88依赖型信号途径为主,并通过激活NF-κB促进炎性因子释放。