消退素D1(resolvin D1)抑制小鼠激活型小胶质细胞对PC12细胞的损伤及机制

目的探讨消退素D1(Rv D1)在小鼠活化BV-2小胶质细胞介导PC12神经元损伤中所起的作用及相关机制。方法BV-2细胞分为对照组、脂多糖(LPS)处理组、Rv D1联合LPS处理组和Rv D1组。各组BV-2细胞处理12 h、24 h,ELISA检测上清液中白细胞介素1β(IL-1β)、IL-6、肿瘤坏死因子α(TNF-α)的水平;收集以上各组细胞培养24 h的上清液培养PC12细胞24 h后,MTT法检测PC12细胞存活率,Western blot法检测各组BV-2细胞核因子κB p65(NF-κB p65)蛋白的水平。结果与对照组比较,LPS处理的PC12细胞存活率降低,BV-2细胞上清液中IL-1β、IL-6、TNF-α的水平均升高,NF-κB p65核转位增加;而与LPS处理组相比,Rv D1联合LPS处理组PC12细胞存活率升高,BV-2细胞上清液中IL-1β、IL-6、TNF-α的含量均降低,NF-κB p65核转位减少。结论 Rv D1可通过抑制NF-κB p65核转位,抑制LPS激活的BV-2细胞对PC12神经元的损伤。     

草木犀流浸液片对脓毒症大鼠肺组织VEGF及肺血管通透性的影响

探讨草木犀流浸液片对盲肠结扎穿孔术(CLP)脓毒症大鼠肺VEGF及肺血管通透性的影响。将80只雄性SD大鼠随机分为四组:①正常对照组20只;②假手术组20只;③对照组20只;④治疗组20只。假手术组只开腹,不行CLP;对照组和治疗组建立CLP脓毒症模型。术前2h治疗组给予草木犀流浸液片20mg/kg,每8h一次,24h处死各组大鼠大鼠,观察肺组织VEGF mRNA、NF-κB mRNA、NF-κB p65及血清VEGF-a、TNF-α、IL-6、IL-1β、IL-8、IFN-γ、IL-10、IL-12的变化;同时测定肺组织通透性(EB)、湿/干重比(W/D)及肺组织病理变化。研究发现:与正常对照组比较,VEGFmRNA、NF-κB p65mRNA、NF-κB p65、VEGF、TNF-α、IL-6、IL-1β、IL-8、IFN-γ、IL-10、IL-12在假手术者无明显变化,差异无统计学意义P>0.05;对照组、治疗组显著升高,差异有非常显著意义P<0.01;与对照组比较,治疗组VEGF mRNA、NF-κB p65mRNA、NF-κB p65、VEGF、TNF-α、IL-6、IL-1β、IL-8显著降低,IFN-γ、IL-10、IL-12显著升高,差异有统计学意义P<0.05。VEGF mRNA与NF-κB mRNA、VEGF与NF-κB p65分别具有正相关性(r=0.852,P<0.05;r=0.794,P<0.05)。病检也发现,治疗组肺病病理损伤较对照组明显减轻。结果提示:草木犀流浸液片能够抑制CLP脓毒症大鼠肺组织NF-κB mRNA、VEGF mRNA的表达,降低血清VEGF、TNF-α、IL-6、IL-1β、IL-8水平,促进IFN-γ、IL-10、IL-12的产生,显著降低脓毒症大鼠肺组织微血管通透性,对脓毒症大鼠肺组织具有保护作用。     

miR-410-3p通过介导HMGB1的表达调控NF-κB信号通路调控缺氧缺血性脑损伤北大核心CSCD

目的:探究miR-410-3p通过介导HMGB1的表达调控NF-κB信号通路调控缺氧缺血性脑损伤的机制。方法:进行PC12细胞培养并分组:Normal组(正常PC12细胞)、NC组(缺血性处理的PC12细胞,转染阴性对照质粒)、Model组(缺血性处理的PC12细胞)、miR-410-3p mimic组(缺血性处理的PC12细胞,转染miR-410-3p过表达质粒)、HMGB1 vector组(缺血性处理的PC12细胞,转染HMGB1过表达质粒)、miR-410-3p mimic+HMGB1 vector组(缺血性处理的PC12细胞,共染miR-410-3p过表达和HMGB1过表达质粒)。双荧光素酶报告实验验证miR-410-3p和HMGB1靶向关系。Western blot检测各组细胞中HMGB1、NF-κB p65的蛋白表达情况,qRT-PCR检测miR-410-3p表达情况。CCK8和流式细胞术分别检测各组细胞增殖和凋亡情况。ELISA检测各组细胞炎症因子IL-8、IL-6、TNF-α含量。结果:miR-410-3p与HMGB1存在靶向关系。与Normal组相比,其余组细胞中miR-410-3p表达显著降低,HMGB1表达显著升高(均P<0.05)。与Normal组对比,其余各组细胞的增殖率明显下降,细胞凋亡率,炎症因子IL-8、IL-6、TNF-α含量,HMGB1、NF-κB p65水平均明显升高(均P<0.05)。miR-410-3p可促进细胞增殖,降低细胞凋亡率、炎症因子IL-8、IL-6、TNF-α含量及NF-κB p65水平,且miR-410-3p可通过负向调控HMGB1的表达,从而影响HMGB1/NF-κB通路对缺血性神经元的调控。结论:miR-410-3p过表达后,可通过抑制HMGB1/NF-κB通路表达,从而影响脑缺血性神经元细胞增殖、凋亡以及炎症损伤。     

雷公藤甲素对去势小鼠骨质疏松模型破骨细胞分化的影响

目的 探究雷公藤甲素（TP）对去势小鼠骨质疏松模型破骨细胞分化的影响，并探讨其可能的分子机制。方法 建立去势小鼠骨质疏松模型，分为假手术组（Sham组）、卵巢切除去势组（OVX组）、雷公藤甲素组（TP组）、利维爱组（Livial组），造模后第3天给予对应药物处理。治疗6周后，采用TRAP染色检测左侧股骨干骺端的破骨细胞数量。Micro-CT重建三维骨结构图像，检测左侧胫骨干骺端的骨密度（BMD）、骨小梁数目（Tb.N）、骨体积分数（BV/TV）、骨表面积组织体积比（BS/TV）、骨小梁分离度（Tb.Sp），ELISA检测外周血中IL-6、TNF-α、骨形成标志物骨钙素（OC）、骨吸收标志物抗酒石酸酸性磷酸酶（TRAcp5b）含量。Western Blot检测右侧股骨组织中p65、p-p65、IκBα、p-IκBα蛋白表达水平。结果 骨小梁周围破骨细胞数量比较：OVX组与Sham组相比明显增加；TP组与OVX组相比明显减少；TP组与Livial组比较，差异无统计学意义。骨参数分析：OVX组与Sham组相比，小鼠骨组织的BMD、Tb.N、BV/TV、BS/TV均显著下降，而Tb.Sp显著升高（P＜0.01）；与OVX组相比，TP组和Livial组骨组织的BMD、Tb.N、BV/TV、BS/TV均显著升高，而Tb.Sp显著下降（P＜0.01）；TP组与Livial组比较，差异无统计学意义（P＞0.05）。IL-6、TNF-α、OC、TRAcp5b含量比较：OVX组的IL-6、TNF-α含量显著高于Sham组（P＜0.01）；各组间OC水平比较，差异无统计学意义（P＞0.05）；OVX组的TRAcp5b水平显著高于Sham组（P＜0.01）。蛋白表达水平：与Sham组相比，OVX组的p65、IκBα表达水平不变，而p-p65和p-IκBα表达水平显著升高（P＜0.01）；TP处理后，p65、IκBα表达水平不变，而p-p65和p-IκBα表达水平却显著降低（P＜0.01）；TP组与Livial组比较，两者间p65、IκBα、p-p65和p-IκBα表达水平差异无统计学意义（P＞0.05）。结论 TP抑制破骨细胞分化，改善了去势小鼠的骨量丢失，其分子机制可能与抑制炎症因子IL-6、TNF-α的表达及NF-κB信号通路的磷酸化水平有关。     

ox-LDL对巨噬细胞内皮脂肪酶表达的影响

目的: 探讨氧化低密度脂蛋白(ox-LDL)对鼠源RAW264.7巨噬细胞内皮脂肪酶(EL)表达的影响。方法: 用ox-LDL(0~100 mg/L)孵育RAW264.7细胞24 h使其活化,或者用PDTC (NF-κB抑制剂)预孵育RAW264.7细胞30 min再与ox-LDL(50 mg/L)共同孵育24 h;应用Western blotting 检测EL和NF-κB p65的表达。结果: ox-LDL孵育RAW264.7细胞明显增加EL表达(P<0.05);ox-LDL(50 mg/L)孵育RAW264.7细胞15~30 min可激活NF-κB,用NF-κB 抑制剂PDTC处理后则明显抑制ox-LDL诱导的EL表达增加(P<0.05)。结论: ox-LDL可明显增加RAW264.7细胞EL的表达,可能与NF-κB活化有关。     

RNAi沉默NF-κB p65对小鼠巨噬细胞细胞因子表达的影响

目的:探讨RNA干扰(RNAi)技术在抑制NF-κB p65表达、调控LPS活化后巨噬细胞细胞因子表达中的应用.方法:利用阳离子脂质体将NF-κB p65小干扰RNA(siRNA)瞬时转染入Ana-1细胞,RT-PCR及Western blotting法检测其沉默效率,ELISA法检测LPS(1 mg/L)刺激下0 h、4 h、12 h和24 h Ana-1细胞培养上清中TNF-α、IL-1β、IL-6和IL-10浓度.结果:NF-κB p65 siRNA转染24 h后,NF-κB p65在基因水平及蛋白水平表达均被明显抑制(P<0.05).RNA干扰组Ana-1细胞培养上清中细胞因子TNF-α、IL-1β和IL-6表达在相应时点内均较对照组明显降低(P<0.05),IL-10表达显著升高,在12 h和24 h差异显著(P<0.05).结论:体外实验初步证实RNAi技术能有效沉默小鼠巨噬细胞NF-κB p65基因的表达,下调其下游调控的促炎症细胞因子TNF-α、IL-1β、IL-6及上调抑炎症细胞因子IL-10的表达,从而抑制过度的炎症反应.     

核因子-κB对TNF-α诱导的大鼠气道平滑肌细胞增殖、凋亡及TGF-β1表达的影响

目的: 探讨核因子-κB(NF-κB)对TNF-α诱导的大鼠气道平滑肌细胞（ASMCs）增殖、凋亡和转化生长因子β₁（TGF-β₁）表达的影响。方法: 体外培养ASMCs，以肿瘤坏死因子-α（TNF-α）及NF-κB特异性抑制剂二硫代氨基甲酸吡咯烷(PDTC)作为工具药,将ASMCs分为对照组、TNF-α组和TNF-α+PDTC组。逆转录聚合酶链式反应(RT-PCR)检测TGF-β₁ mRNA表达，Western blotting检测NF-κB、TGF-β₁的表达，免疫细胞化学染色法检测PCNA、Bcl-2蛋白表达及定位，四甲基偶氮唑蓝(MTT)微量比色法测定ASMCs增殖，Annexin V/PI双标记流式细胞仪分析法检测细胞凋亡。结果: （1）TNF-α组ASMCs的NF-κB活性显著高于对照组(P<0.01),TNF-α+PDTC组NF-κB活性显著低于TNF-α组 (P<0.01)。（2）TNF-α组ASMCs增殖显著高于对照组(P<0.01),TNF-α＋PDTC组的增殖反应显著低于TNF-α组(P<0.01)；TNF-α+PDTC组细胞凋亡率显著高于TNF-α组及对照组(P<0.01)。（3）TNF-α组ASMCs的PCNA、Bcl-2蛋白表达量均显著高于对照组(P<0.01)，TNF-α+PDTC组的PCNA、Bcl-2蛋白表达量均显著低于TNF-α组(P<0.01)。（4）TNF-α组ASMCs的TGF-β₁的mRNA及蛋白表达水平均显著高于对照组及TNF-α＋PDTC组（P<0.01）。结论: NF-κB活化可能参与调控TNF-α诱导的大鼠气道平滑肌细胞的增殖、凋亡及TGF-β₁的表达和分泌。     

乌司他丁对心肺复苏后兔脑组织氧化应激损伤的影响

目的: 观察乌司他丁(ulinastatin,UTI)对心肺复苏(cardiopulmonary resuscitation, CPR)后新西兰兔脑组织氧化应激损伤的影响。方法: (1)建立新西兰兔心脏停搏(cardiac arrest,CA)模型,自主循环恢复(return of spontaneous circulation,ROSC)后24 h内连续采血监测血浆丙二醛(malondialdehyde, MDA)和还原型谷胱甘肽 (glutathione, GSH)的水平;(2) 48只新西兰兔建立CA模型,ROSC后随机分为模型组(model组)和UTI治疗组,观察UTI对大脑皮层和海马内MDA、GSH含量和神经元凋亡的影响,观察UTI对大脑皮层核因子E2 相关因子2(nuclear factor E2-related factor 2, Nrf2)表达的影响。结果: ROSC后2 h 血浆MDA达高峰,GSH降低到较低水平;UTI显著抑制ROSC后大脑皮层和海马MDA水平的升高,提高GSH含量。UTI促进了ROSC后脑组织Nrf2的表达。Model组大脑皮层及海马CA1~CA3区的凋亡神经元数明显多于UTI组。结论: UTI可升高ROSC后兔脑组织GSH水平,降低MDA含量,增加Nrf2的表达,减少神经元的凋亡。     

沙立度胺对大鼠肝纤维化核因子-κB和肿瘤坏死因子-α表达的影响

目的： 观察沙立度胺抗大鼠肝纤维化的疗效和对NF-κB和TNF-α表达的影响。方法： 四氯化碳腹腔注射诱导大鼠肝纤维化模型，治疗组于造模同时用沙立度胺10 mg·kg^-1·d^-1和100 mg·kg^-1·d^-1灌胃8周。观察肝组织病理学改变，检测肝功能、血清肝纤维化指标及肝组织羟脯氨酸含量，免疫组化检测NF-κB p65、α-SMA 在肝内的表达和分布，Western blotting检测肝组织NF-κB p65、IκBα、TNF-α蛋白的表达，RT-PCR检测肝组织TNF-α mRNA表达。结果： 高剂量沙立度胺治疗组肝脏炎症及纤维化程度低于模型组；其ALT、AST水平,HA、LN及羟脯氨酸含量，肝组织细胞核NF-κB p65和肝组织α-SMA蛋白表达，以及肝组织TNF-α mRNA和蛋白表达均低于模型组(P<0.01）；而PA水平和细胞质中IκBα蛋白表达高于模型组(P<0.01)。结论： 沙立度胺可有效地抑制实验性大鼠肝纤维化的发展，通过抑制IκB解离和降解从而减弱NF-κB通路对TNF-α表达的诱导可能是它发挥疗效的机制之一。     

醛糖还原酶抑制剂抑制屋尘螨诱导的人支气管上皮细胞系BEAS-2氧化应激反应

目的 探究醛糖还原酶抑制剂ARIs抑制屋尘螨诱导的人支气管上皮细胞系BEAS-2B氧化应激反应。方法 将BEAS-2B分为对照组、模型组、NF-κB抑制剂组(PDTC组)和ARIs干预组(ARIs组)。检测氧化应激指标(MDA和ROS含量、SOD活性);ELISA检测IL-5、IL-13、IFN-γ含量;MTT法检测细胞存活率;流式细胞仪检测细胞凋亡;蛋白质印迹检测细胞内NF-κB、NF-κB p65和p38 MAPK蛋白表达。结果 模型组细胞中SOD活性、IFN-γ含量及细胞存活率均低于对照组(P<0.05),MDA、IL-5、IL-13含量及细胞凋亡率高于对照组(P<0.05);与模型组相比,PDTC组和ARIs组细胞中SOD活性、IFN-γ含量及细胞存活率升高(P<0.05),MDA、IL-5、IL-13含量及细胞凋亡率降低(P<0.05);和对照组相比,模型组细胞中NF-κB、NF-κB p65和p38 MAPK蛋白表达均显著增加(P<0.05);和模型组相比,PDTC组和ARIs组细胞中NF-κB、NF-κB p65和p38 MAPK蛋白表达均明...     

Resveratrol protects BV2 mouse microglial cells against LPS-induced inflammatory injury by altering the miR-146a-5p/TRAF6/NF-κB axis

Abstract

Objective: To investigate the role of miR-146a-5p in the effects of resveratrol (RSV) on inflammatory response in BV2 mouse microglial cells.

Materials and methods: BV2 cells were pretreated by RSV and stimulated with lipopolysaccharide (LPS). Cell Viability was checked using a MTT assay. Real-Time PCR was performed to detect the levels of pro-inflammatory cytokines (tumor necrosisfactor-α－TNF-α, interleukin-1β－IL-1β and interleukin-6 － IL-6) and miR-146a-5p expression. Western blot was used to analyze the protein expression of TNF receptor associated factor 6 (TRAF6) and phospho-nuclear factor kappa B (pNF-κB). Gain-of-function and loss-of-function analysis of miR-146a-5p was performed using transfection of miR-146a-5p mimic and miR-146a-5p inhibitor, respectively.

Results: Pretreatment with RSV significantly and dose dependently inhibited LPS-induced production of TNF-α, IL-1β and IL-6 in BV2 cells. MiR-146a-5p was significantly upregulated after LPS treatment, and further increased in RSV and LPS-co-treated cells. MiR-146a-5p overexpression via miR-146a-5p mimic transfection downregulated the mRNA level of TNF-α, IL-1β and IL-6, as well as abrogated the protein expression of TRAF6 and pNF-κB in BV2 cells exposed to LPS. More importantly, the reducion of TNF-α, IL-1β and IL-6 level by RSV were reversed by miR-146a-5p silence via miR-146a-5p inhibitor transfection. Furthermore, silencing miR-146a-5p attenuated the inhibitory effect of RSV on the TRAF6/NF-κB pathway which was activated after induction with LPS. Conclusions: RSV can suppress LPS-induced inflammatory injury via modulating the miR-146a-5p/TRAF6/NF-κB axis in BV2 mouse microglial cells.     

Biphasic activation of nuclear factor kappa B and expression of p65 and c-Rel after traumatic brain injury in rats

Background and object

Nuclear factor kappa B (NF-κB) functions as a key regulator in the central nervous system and regulates the inflammatory pathway. There are two peaks of cerebral NF-κB activation after neonatal hypoxia–ischemia and subarachnoid hemorrhage. Our previous studies found that NF-κB activity was up-regulated at an early stage and remained elevated at day 7 after traumatic brain injury (TBI). However, data are lacking regarding an overview of NF-κB activity and expression of NF-κB subunits after TBI. Hence, the current study was designed to detect the time course of NF-κB activation and expression of NF-κB p65 and c-Rel subunits around the contused cortex following TBI.

Methods

Adult Sprague–Dawley rats were randomly divided into sham and TBI groups at different time points. A TBI model was induced, and then the NF-κB DNA-binding activity in the surrounding areas of injured brain was detected by electrophoretic mobility shift assay. Western blotting was used to measure the protein levels of p65 and c-Rel in the nucleus. The concentrations of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected by enzyme-linked immunosorbent assay. Moreover, the distribution of c-Rel and p65 was examined by immunohistochemical studies.

Results

There were double peaks of cerebral cortical NF-κB activity, at 3 and 10 days post-injury. Additionally, protein levels of p65 were found to be elevated and peaked at 3 days after TBI, while levels of c-Rel were elevated significantly during the later phase of injury. Furthermore, TNF-α and IL-1β concentrations also showed a biphasic increase.

Conclusions

Biphasic activation of NF-κB could be induced after experimental TBI in rats. NF-κB p65 and c-Rel subunits were elevated at different post-TBI time periods, leading to a hypothesis that different NF-κB subunits might be involved in different pathophysiological processes after TBI.     

Regulatory effect of IL-38 on NF-κB pathway in systemic lupus erythematosus

BackgroundIL-38 is a newly identified cytokine that exhibits immunosuppression effects. However, there are few studies focusing on the effects and mechanisms of IL-38 in the systemic lupus erythematosus (SLE).AimWe investigated the effects and mechanisms of IL-38 on NF-κB signaling pathway in SLE.MethodsLevels of IL-38, IL-36R, IL-1RAcP, IKKα/β, NF-κB, TNF-α and anti-dsDNA antibody levels in peripheral blood of SLE patients, and in peripheral blood and kidney tissues of MRL/lpr mice, were examined with real-time PCR, ELISA, Western blot and immunohistochemistry. Pathological changes of kidney were detected with PAS staining. Recombinant human IL-38 protein and IL-38 siRNA were used to intervene the PBMCs of SLE patients and MRL/lpr mice.ResultsThe mRNA and protein levels of IL-38 in peripheral blood of SLE patients decreased and were positively correlated. The mRNA and protein levels of IKKα/β, NF-κB, and TNF-α increased, especially in patients with active SLE. There was a negative correlation between IL-38 and the levels of IKKα/β, NF-κB and TNF-α in SLE patients. In vitro experiments showed that the levels of IKKα/β, NF-κB and TNF-α, and anti-dsDNA antibodies decreased in PBMCs of SLE patients after treatment with human recombinant IL-38 protein. These effects were reversed after IL-38 siRNA intervention. Consistent results were obtained on IL-38, IKKα/β, NF-κB, and TNF-α in MRL/lpr lupus mice after treatment with IL-38 protein or IL-38 shRNA. Additionally, kidney function (reflected by creatinine and blood urea nitrogen), anti-dsDNA antibody, complement C3, and urinary protein levels decreased after treatment with IL-38 protein but increased after IL-38 shRNA treatment. PAS staining showed IL-38 protein treatment induced mild hyperplasia of glomerular mesangial cells and a small amount of lymphocyte infiltration. However, these were aggravated after IL-38 shRNA treatment.ConclusionIL-38 may be involved in the occurrence and development of SLE by regulating the NF-κB signaling pathway. This study only discussed the relationship between IL-38 and NF-κB, and more biological functions of IL-38 need to be further studied.     

沉默NF-κB p65基因下调TNF-α诱导的肺泡上皮细胞的炎症反应

目的建立急性肺损伤体外细胞炎症模型,探讨NF-κB p65基因沉默减轻细胞炎症、保护肺结构细胞的可行性。方法以TNF-α(10 ng/ml)刺激肺泡Ⅱ型上皮细胞(A549),运用RNA干扰技术沉默NF-κB p65基因,采用RT-PCR及Westernblotting法检测沉默效率,ELISA法检测细胞培养上清中IL-1β、IL-8、IL-10等炎症因子浓度。结果 TNF-α刺激A549细胞可在基因水平上调NF-κB p65的表达,并增加NF-κB蛋白的核转位,上调细胞培养上清中IL-1β、IL-8、IL-10的浓度;预转染NF-κB p65 siRNA可在基因水平及蛋白水平有效沉默NF-κB p65表达,降低上述各炎症因子浓度(P<0.05)。结论急性肺损伤体外细胞炎症模型构建成功,RNA干扰技术能有效沉默该模型NF-κB p65基因,下调炎症反应水平,保护肺泡上皮细胞,为急性肺损伤免疫调控机制的研究和基因靶向治疗提供实验依据。     

Inflammatory factor-specific sumoylation regulates NF-κB signalling in glomerular cells from diabetic rats

Objective

The activation of nuclear factor (NF)-κB by cytokines under hyperglycaemic conditions is a potential mechanism for complications in diabetes. We investigated whether small ubiquitin-like modifier 4 (SUMO4) regulates renal NF-κB signalling in diabetic rats.

Methods

Histological changes in kidney were analysed in diabetic GK rats. The expressions of tumour necrosis factor (TNF)-α, NF-κB (p65), IκBα and SUMO4 in renal tissues were examined by immunohistochemistry and Western blotting. Primary cultured glomerular endothelial cells from rats were stimulated by TNF-α or interleukin (IL)-2.

Results

The renal expression of TNF-α, NF-κB (p65), IκBα and SUMO4 was significantly higher in diabetic GK rats than in control rats. In control rats, no nuclear translocation was observed for IκBα or NF-κB (p65). However, in diabetic GK rats, translocation of NF-κB (p65) and IκBα into the nucleus was observed, and the expression of SUMO4 and IκBα was up-regulated in the glomerular endothelial cells. SUMO4 was localised in both the cytoplasm and nucleus, while IκBα was predominantly located in the nucleus after stimulation with TNF-α. In contrast, SUMO4 was localised in the nucleus, and increased cytoplasm SUMO4 localisation was found after stimulation with IL-2.

Conclusions

SUMO4 plays a role in regulating NF-κB signalling in glomerular cells. Cytokines have a unique effect in regulating the sumoylation of NF-κB.     

Hyperlipidemia Modifies Innate Immune Responses to Lipopolysaccharide via the TLR-NF-κB Signaling Pathway

The objective of this study was to investigate the effect of hyperlipidemia (HLP) on innate immune responses to lipopolysaccharide (LPS). Male New Zealand white rabbits were fed a normal diet (ND) or a high-fat diet (HFD) for 8 weeks. In vivo, the rabbits were injected intravenously with LPS for 24 h. In vitro, peripheral mononuclear cells were collected and stimulated (or unstimulated) with LPS for 24 h. Assay results were analyzed with one-way ANOVA or an equivalent non-parametric test. A P value of 0.05 was considered statistically significant. Despite having no influence in body weight, the HFD intake significantly increased serum lipids, C-reactive protein (CRP), nuclear factor (NF)-κB subunit p65, Toll-like receptor (TLR)-4, SR-A and FAS. Although we found increased circulating tumor necrosis factor (TNF)-α, interleukin (IL)-6, CRP, IL-1β, and IL-10 in the ND-fed rabbits, no significant difference was found in the LPS-stimulated production of TNF-α, IL-6, and CRP in the HFD-fed rabbits. The macrophages harvested from the HFD-fed rabbits developed a blunted inflammatory response, with lower mRNA expression of TNF-α, IL-6, CRP, TLR-4, SR-A, FAS, and Bcl-2 than that expressed by the ND group. In the HFD-fed animals, LPS incubation decreased NF-κB subunit p65 expression, whereas the cytoplasmic phosphorylation of the inhibitor of NF-κB protein was enhanced. These data indicate that HLP displayed a form of innate immune paralysis, including reduced pro- and anti-inflammatory cytokine release to external stimulus, which was related to the altered TLR-NF-κB signaling pathway and altered pro- and anti-apoptotic processes in macrophages.     

A Novel Gain-of-Function IKBA Mutation Underlies Ectodermal Dysplasia with Immunodeficiency and Polyendocrinopathy

Purpose

This study reports the identification of a novel heterozygous IKBA missense mutation (p.M37K) in a boy presenting with ectodermal dysplasia with immunodeficiency (EDA-ID) who had wild type IKBKG gene encoding NEMO. Our aim was to characterize the clinical course of this IκB-α gain-of-function mutant and to investigate if the p.M37K substitution affects NF-κB activation by interfering with IκB-α degradation, thus impairing NF-κB signaling and causing the EDA-ID phenotype.

Methods

NF-κB signaling was evaluated by measuring IκB-α degradation in patient fibroblasts. In addition, transiently transfected HeLa cells expressing either the M37K-mutant IκB-α allele, the previously characterized S36A-mutant IκB-α allele, or wild type IκB-α were evaluated for IκB-α degradation and NF-κB nuclear translocation following stimulation with TNF-α.

Results

Clinical findings revealed a classical ectodermal dysplasia phenotype complicated by recurrent mucocutaneous candidiasis, hypothyroidism, hypopituitarism, and profound combined immunodeficiency with decreased numbers of IL-17 T cells. IκB-α degradation after TNF-α and TLR agonist stimulation was abolished in patient fibroblasts as well as in HeLa cells expressing M37K-IκB-α similar to cells expressing S36A-IκB-α resulting in impaired nuclear translocation of NF-κB and reduced NF-κB dependent luciferase activity compared to cells expressing wild type IκB-α. Patient whole blood cells failed to secrete IL-6 in response to IL-1ß, Pam₂CSK₄, showed reduced responses to LPS and PMA/Ionomycin, and lacked IL-10 production in response to TNF-α.

Conclusion

The novel heterozygous mutation p.M37K in IκB-α impairs NF-κB activation causing autosomal dominant EDA-ID with an expanded clinical phenotype.     

NF-κB抑制剂减低LPS致兔腰椎间盘髓核细胞锌指蛋白A20表达升高

目的观察脂多糖(LPS)刺激退变兔椎间盘髓核细胞前后,锌指蛋白A20(A20)、NF-κB及相关炎性因子的表达及其相互关系。方法获取正常和退变兔腰椎间盘髓核细胞,分为正常组、退变组、LPS刺激组和NF-κB抑制剂组,HE染色观察椎间盘髓核及纤维环的形态,免疫组化检测椎间盘A20、NF-κB p65蛋白及Ⅱ型胶原(COL-Ⅱ)的表达。Real-time PCR分别检测各组A20、IL-1β、TNF-α、NF-κB和COL-ⅡmRNA的表达。Western blot观察A20、p65和COL-Ⅱ的表达。ELISA检测细胞培养上清液中IL-1β、TNF-α的表达。结果退变组髓核细胞数量明显减少,髓核细胞聚集成团,COL-Ⅱ表达下降,A20和p65蛋白表达升高;与正常组相比,退变组A20、TNF-α、IL-1β和p65表达在mRNA及蛋白水平均明显升高,COL-Ⅱ表达降低(P0.05);LPS刺激组中A20、TNF-α、IL-1β和p65表达较退变组更显著,COL-Ⅱ降低明显(P0.05);NF-κB抑制剂组较LPS刺激组A20、TNF-α、IL-1β和p65表达回降,COL-Ⅱ表达回升(P0.05)。结论髓核细胞炎性反应与兔椎间盘退变的发生和发展密切相关,其中A20可能发挥了重要作用。     

TNF-α抗体对Sp1和NF-κ B p65在兔粘连腹膜表达的影响

目的探讨TNF-α抗体对实验兔腹膜损伤粘连修复演变过程中核转录因子Sp1和NF-κB p65活化的影响。方法实验兔随机分3组:正常对照组(不做任何处理)、模型组(腹膜腔内注入生理盐水)、TNF-α抗体组(造模后后腹膜腔内注入TNF-α抗体),每组30只,共90只。建立实验兔腹膜回盲部手术动物模型,ELISA检测腹水Sp1、NF-κB p65的表达,Masson染色检测Sp1在腹膜的表达、免疫组化SP法检测NF-κB p65在腹膜的表达,监测腹膜粘连分级变化。结果 TNF-α抗体导致Sp1和NF-κB p65在损伤腹膜和腹水中的表达水平显著减低(0.01),并有效减轻腹膜粘连形成。结论 TNF-α抗体有效减轻腹膜粘连形成可能与其下调Sp1和NF-κB p65表达相关。     

Protective effect of gossypol on lipopolysaccharide-induced acute lung injury in mice

Objective

Gossypol has been reported to have anti-inflammatory properties. The purpose of this study was to evaluate the effect of gossypol on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice.

Methods

Male BALB/c mice were pretreated with gossypol 1 h before intranasal instillation of LPS. Then, 7 h after LPS administration, the myeloperoxidase in histology of lungs, lung wet/dry ratio and inflammatory cells in the bronchoalveolar lavage fluid (BALF) were determined. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in the BALF were measured by ELISA. The extent of phosphorylation of IκB-α, p65 NF-κB, p46–p54 JNK, p42–p44 ERK, and p38 were detected by western blot.

Results

Gossypol markedly attenuated the LPS-induced histological alterations in the lung and inhibited the production of TNF-α, IL-1β and IL-6. Additionally, gossypol reduced the inflammatory cells in BALF, decreased the wet/dry ratio of lungs and inhibited the phosphorylation of IκB-α, p65 NF-κB, p46–p54 JNK, p42–p44 ERK, and p38 caused by LPS.

Conclusion

The data suggest that anti-inflammatory effects of gossypol against the LPS-induced ALI may be due to its ability of inhibition of the NF-κB and MAPKs signaling pathways. Gossypol may be a promising potential therapeutic reagent for ALI treatment.