Unfractionated heparin suppresses lipopolysaccharide-induced monocyte chemoattractant protein-1 expression in human microvascular endothelial cells by blocking Krüppel-like factor 5 and nuclear factor-κB pathway

Unfractionated heparin (UFH) and low-molecular-weight heparins (LMWH), apart from anticoagulant activities, contain a variety of biological properties such as anti-inflammatory actions possibly affecting sepsis. Chemokines are vital for promoting the movement of circulating leukocytes to the site of infection and are involved in the pathogenesis of sepsis. The purpose of this study was to investigate the effects and potential mechanisms of UFH on lipopolysaccharide (LPS)-induced chemokine production in human pulmonary microvascular endothelial cells (HPMECs). HPMECs were pretreated with UFH (0.1 U/ml and 1 U/ml), 15 min prior to stimulation with LPS (10 μg/ml). Cells were cultured under various experimental conditions for 2 h and 6 h for analysis. UFH markedly decreased LPS-induced interleukin (IL)-8 and monocyte chemoattractant protein-1 (MCP-1) mRNA and protein expression in HPMECs. UFH also attenuated the secretion of these chemokines in culture supernatants. In addition, UFH blocked the chemotactic activities of LPS-stimulated HPMECs supernatants on monocytes migration as expected. UFH inhibited LPS-induced Krüppel-like factor 5 (KLF-5) mRNA and protein levels. Concurrently, UFH reduced nuclear factor (NF)-κB nuclear translocation. Importantly, transfection with siRNA targeting KLF-5 reduced NF-κB activation and chemokines expression. These results demonstrate that interfering with KLF-5 mediated NF-κB activation might contribute to the inhibitory effects of chemokines and monocytes migration by UFH in LPS-stimulated HPMECs.     

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.     

PGE2 和 NF-κB信号途径在骨再生中的相互作用

目的　本研究旨在利用MC3T3-E1 成骨细胞株与大鼠骨折模型来研究骨折愈合过程中PGE2和NF-κB信号途径的相互作用。 方法　利用PGE2与NF-κB 抑制剂 BAY 11-7082处理MC3T3-E1成骨细胞和大鼠骨折模型，采用碱性磷酸酶活性测定、Western blot 分析、EMSA分析以及ELISA测定等研究手段，研究PGE2、NF-κB、BMP-7、 Id2以及SOD2在骨再生中的作用。 结果　利用10 μmol/l PGE2处理MC3T3-E1细胞10 min, 30 min 和2h后，能够显著地促进成骨细胞增殖与分化，当细胞用5 μmol/L BAY 11-7082处理后，PGE2诱导作用受到抑制，表明 PGE2 增加ALP的表达是通过NF-κB 途径来介导。局部注射NF-κB 抑制剂后 PGE2 的生物合成明显减少；此外，抑制骨折部位ALP的活性，在骨折的损伤修复过程中，NF-κB、BMP-7以及SOD2 的表达均明显上升，而Id2的表达明显下降；加入NF-κB活性抑制剂后，BMP-7与Id2的表达恢复到正常水平，而SOD2的表达没有改变。　结论 　PGE2能够同时通过抑制Id2细胞因子和激活NF-κB信号途径诱导成骨细胞分化。     

NF-κB介导大鼠肾小球系膜细胞Visfatin对肾素血管紧张素系统mRNA表达的影响

目的观察大鼠肾小球系膜细胞中内脏脂肪素（Visfatin）对肾素血管紧张素系统（RAS）mRNA表达的影响及探讨其机制。方法分别构建Visfatin表达载体质粒及Visfatin RNAi表达载体质粒,将细胞分为8组：正常糖对照组、正常糖＋NF-κB特异性抑制剂吡咯烷二硫基甲酸酯（PDTC）组、过表达Visfatin组、过表达Visfatin＋PDTC组、空白过表达载体组、空白过表达载体＋PDTC组、Visfatin RNAi组及空白沉默载体组,用Realtime-PCR方法检测血管紧张素原（AGT）、血管紧张素转化酶（ACE）、血管紧张素Ⅱ1型受体（AT1R）、血管紧张素Ⅱ2型受体（AT2R）等RAS相关基因表达,使用电泳迁移率变动分析法（EMSA）检测NF-κB活性,比较各组间基因表达及NF-κB活性的差异;以及通过观察PDTC处理对照组、过表达Visfatin组、空白过表达载体组前后上述指标的变化。结果细胞过表达Visfatin后,NF-κB活性、Visfatin、AGT、AT1R mRNA表达量显著升高,分别为正常糖对照组的1.52、11.42、2.85、1.25倍（P均〈0.01）;转染RNAi质粒pSIREN-Visfatin/sh RNA后,NF-κB活性、Visfatin、AGT、AT1R mRNA表达量显著降低,分别为正常糖对照组的10.90%、26.83%、30.00%、73.47%（P均〈0.01）。经PDTC处理的各组NF-κB活性、AGT mRNA表达量与相应的未经PDTC处理组相比显著降低（P〈0.01）,正常糖＋PDTC干预组NF-κB活性、AGT mRNA表达量是正常糖对照组的21.60%、34.59%;过表达Visfatin＋PDTC干预组的NF-κB活性、AGT mRNA表达量是过表达Visfatin组的37.96%、19.72%;空白过表达载体＋PDTC干预组NF-κB活性、AGT mRNA表达量是空白表达载体组的52.53%、33.08%,差异均具有统计学意义（P〈0.01）。结论在大鼠肾小球系膜细胞中,Visfatin可通过NF-κB引起RAS相关基因表达的变化。     

α7烟碱型乙酰胆碱受体激动剂抑制骨水泥微粒刺激小鼠外周血单核细胞分泌炎性因子

目的探讨α7烟碱型乙酰胆碱受体(α7n AChR)激动剂PNU282987对骨水泥微粒刺激小鼠外周血单核细胞分泌炎性反应因子的影响及其分子机制。方法分离培养小鼠外周血单核细胞,使用聚甲基丙烯酸甲酯(PMMA)微粒刺激后,ELISA检测培养上清液中TNF-α、IL-1β和IL-6的含量;RT-PCR检测细胞TNF-α、IL-1β和IL-6的mRNA表达;Western blot检测p-p65、p65、p-JAK2、JAK2、p-STAT3、STAT3及β-actin的表达;ELISA检测NF-κB DNA结合活力。结果单核细胞经PMMA微粒刺激后,上清液中TNF-α、IL-1β和IL-6的含量明显增高(P0.05);细胞TNF-α、IL-1β和IL-6 mRNA表达明显增高(P0.05);p65、JAK2和STAT3磷酸化明显增强(P0.05);NF-κB DNA结合活力明显增高(P0.05)。不同浓度PNU282987作用后,上清液中TNF-α、IL-1β和IL-6的含量呈浓度依耐性下降(P0.05);细胞TNF-α、IL-1β和IL-6 mRNA表达呈浓度依耐性下降(P0.05);总p65、JAK2和STAT3的表达不变;p-p65、p-JAK2和p-STAT3的表达呈浓度依耐性下降(P0.05);NF-κB DNA结合活力也呈浓度依耐性下降(P0.05)。结论α7n AChR激动剂PNU282987能显著抑制PMMA骨水泥微粒所诱导的小鼠血单核细胞炎性反应因子的分泌。     

核转录因子κB在中药金叶败毒制剂抗人巨细胞病毒感染中的作用

目的研究核转录因子NF-κB在金叶败毒制剂（简称中药）抗人巨细胞病毒（HCMV）感染中的作用。方法分别应用原位杂交和半定量RT-PCR方法检测中药和更昔洛韦（GCV）干预HCMV感染的细胞NF-κBp65mRNA及HCMV晚期mRNA的表达水平,观察两种药物对HCMV感染致人胚胎成纤维细胞（HEL）病变（CPE）的影响。结果两种药物对HCMV晚期mRNA的表达和HCMV致细胞病变CPE均有抑制作用,但中药能显著抑制NF-κBp65mRNA的水平,而GCV对此影响不明显。结论中药可能通过抑制核转录因子NF-κB而拮抗HCMV感染,NF-κB信号通路激活可能为HCMV致病机制之一。     

WDR5在大鼠肾脏缺血再灌注损伤中的作用及机制研究

目的:探讨WDR5基因在肾脏缺血再灌注损伤中的作用及机制.方法:成年雄性SD大鼠48只,按照随机数表法分为对照组、缺血再灌注损伤组(IR组)、药物溶剂组(DMSO组)、WDR5-0103低剂量组(1mg/kg)、WDR5-0103中剂量组(5mg/kg)、WDR5-0103高剂量组(25mg/kg).对照组:仅切除大鼠...     

肾癌病理组织中核转录因子κB的表达及其意义

目的：探讨核转录因子κB（NF-κB）表达在肾癌发生、发展中的意义。方法：采用免疫组化方法检测66例肾癌病理标本（肾癌组）中NF-κB的表达情况,并与40例非癌肾组织病理标本（对照组）中NF-κB的表达情况比较。结果：肾癌组NF-κB阳性表达率为75.8%,对照组NF-κB阳性表达率为15.0%,肾癌组明显高于对照组（P〈0.05）。NF-κB的表达与肾癌病理组织学分级之间无明显的相关性（P〉0.05）;NF-κB的表达与肾癌的TNM分期之间呈显著的正相关（P〈0.05）。结论：肾癌病程中存在NF-κB的异常激活,NF-κB的表达与肾癌病理组织学分级之间无明显的相关性;NF-κB的表达与肾癌的TNM分期之间呈显著的正相关关系。     

ATP1B3 cooperates with BST-2 to promote hepatitis B virus restriction

Increasing evidence indicates ATP1B3, one of the regulatory subunits of Na⁺/K⁺-ATPase, is involved in numerous viral propagations, such as HIV and EV71. However, the function and mechanism of ATP1B3 on hepatitis B virus (HBV) propagation is unknown. Here, we demonstrated that ATP1B3 overexpression reduced the quantity of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in supernatants of HBV expression plasmids cotransfected HepG2 cells. Correspondingly, small interfering RNA and short hairpin RNA mediated ATP1B3 silencing promoted HBsAg and HBeAg expression in the supernatants of HBV expression plasmids transfected HepG2 cells. Mechanically, we reported that ATP1B3 expression could activate nuclear factor-κB (NF-κB) pathway by inducing the expression, phosphorylation, and nuclear import of P65 for the first time. And NF-κB inhibitor (Bay11) impaired the restraint of ATP1B3 on HBV replication. This counteraction effect of Bay11 proved that ATP1B3-induced NF-κB activation was crucial for HBV restriction. Accordingly, we observed that anti-HBV factors interferon-α (IFN-α) and interleukin-6 (IL-6) production were increased in HepG2 cells after the NF-κB activation. It suggested that ATP1B3 suppressed HBsAg and HBeAg by NF-κB/IFN-α and NF-κB/IL-6 axis. Further experiments proved that ATP1B3 overexpression induced anti-HBV factor BST-2 expression by NF-κB/IFN-α axis in HepG2 cells but not HEK293T cells, and ATP1B3 silencing downregulated BST-2 messenger RNA level in HepG2 cells. As an HBV restriction factor, BST-2 cooperated with ATP1B3 to antagonize HBsAg but not HBeAg in HepG2 cells. Our work identified ATP1B3 as a novel candidate of HBV restrictor with unrevealed mechanism and we highlighted it might serve as a potential therapeutic molecule for HBV infection.     

Calpain inhIbitorⅠ对烧伤小鼠肝脏NF-κB转录及炎性细胞因子分泌的影响

探讨Calpain inhibitor I(CI-I)对严重烧伤小鼠肝脏IκBa表达,NF-κB转录及炎性细胞因子分泌的影响。将CI-Ⅰ腹腔给药预处理小鼠1 h后背部行20%全身体表面积(TBSA)Ⅲ度烧伤,收集肝组织,检测其IκBa表达,NF-κB转录和血清TNF-a、IL-1B、IL-6分泌水平。与烧伤对照组比较,CI-Ⅰ预处理后肝脏NF-κB转录活性和炎性细胞因子分泌有所降低。提示CI-Ⅰ预处理可有效抑制严重烧伤小鼠肝细胞NF-κB活化和血清炎性细胞因子分泌,从而有利于烧伤后的炎症调节。     

NF-κB与肝缺血再灌注损伤

NF-κB是一个重要的核转录调控因子，具有多种转录活性，它介导的跨膜信号转导能够引发多种生物学效应。在肝缺血再灌注损伤过程中，NF-κB能够通过对多种细胞因子的转录调节，从基因水平参与肝组织炎症反应。NF-κB也参与调控肝细胞周期进程，它在肝细胞再生和分化过程中也扮演重要的角色。此外，NF-κB还具有抑制肝细胞凋亡的作用。     

通路抑制剂对Tax诱导的Bcl-3的影响及其在NF-κB激活中作用的研究

目的:通过研究不同通路的抑制剂在TaxP细胞(稳定表达Tax的Jurkat亚细胞系)中对Bcl-3(Human B-cellleukemia protein 3)表达的影响和shRNA Bcl-3对NF-κB转录激活作用的影响,探讨Tax阳性细胞中调控Bcl-3的通路及Bcl-3在NF-κB通路中的作用。方法:将TaxP细胞分别用NF-κB(Nuclear factor-κB)抑制剂、GSK(Glycogen synthase kinase)抑制剂和蛋白酶抑制剂处理后,Western blot检测Bcl-3蛋白的表达情况;将Bcl-3的shRNA质粒转入TaxP细胞中,RT-PCR检测Bcl-3mRNA的表达抑制情况;共转染Bcl-3的shRNA和pNF-κB-luc质粒至Jurkat和TaxP细胞中,检测抑制Bcl-3表达后对NF-κB转录活性的影响。结果:Bcl-3的表达不受GSK抑制剂的影响,但在蛋白酶抑制后有明显的升高;RT-PCR的结果表明,在转染Bcl-3 shRNA质粒后,Bcl-3的mRNA表达有明显的下降,荧光素酶活性结果显示Bcl-3在Jurkat和TaxP细胞中被抑制后NF-κB的转录活性明显下降(P0.05)。结论:Tax诱导的Bcl-3表达不依赖于GSK通路,而NF-κB通路参与了Bcl-3的调控,说明Bcl-3在NF-κB的激活中发挥着促进作用。     

NF-κB与COX-2的正相互作用诱导子宫颈癌细胞生长及抗凋亡

目的探讨NF—κB和COX-2通路之间的相互作用对人子宫颈癌细胞株（Hela细胞）的生长及细胞凋亡的影响。方法应用细胞计数盒（CCK-8）检测细胞存活率;Hoechst33258核染色检测凋亡细胞的形态及数量的改变：Westernblot法检测Caspase-3、NF-κB和COX-2蛋白的表达。结果应用NF．KB抑制剂（PDTC）或COX-2抑制剂（NS-398）处理Hela细胞36h能明显地抑制细胞存活率,PDTC或NS-398处理Hela细胞24h能明显地促进Caspase-3表达,并增加凋亡细胞数量。PDTC处理Hela细胞能显著地抑制COX-2表达,另方面,NS-398处理Hela细胞能抑制NF-κB的表达。结论NF-κB和COX-2通路之间的正相互作用诱导Hela细胞生长及抑制细胞凋亡。     

Early viral protein synthesis is necessary for NF-κB activation in modified vaccinia Ankara (MVA)-infected 293 T fibroblast cells

Modified vaccinia Ankara (MVA) is an attenuated vaccinia virus, and is a promising vaccine vector for variola and monkeypox viruses, as well as for other pathogens. The MVA determinants important for vaccine efficacy and immunogenicity are poorly defined. MVA infection of fibroblast cells activates NF-κB, a characteristic not ascribed to wild-type vaccinia viruses. Thus, NF-κB activation, and the subsequent upregulation of host immune molecules, could be one of the determinants for MVA's immunogenicity. We report that ERK2 phosphorylation, an event preceding and required for NF-κB activation, occurred rapidly after virus infection. ERK2 and NF-κB remained inert when virus endocytosis was prevented, suggesting that virus-host cell interactions were insufficient for activating NF-κB. Inhibition of viral protein synthesis decreased NF-κB activation, and elimination of intermediate and late gene expression did not alter MVA-induced NF-κB activation. Thus, early gene expression activates NF-κB.     

Acute rejection of experimental lung allografts: characterization of intravascular mononuclear leukocytes

Leukocytes interacting with endothelia of lung allografts probably play a seminal role in acute rejection, but have not been characterized before. Transplantation was performed in the Lewis to Lewis and in the Dark Agouti to Lewis rat strain combinations. DNA replication was detected in T-cells on day 2 after pulse-labelling in vivo with 5-bromo-2'-deoxyuridine (BrdU). On day 5, leukocytes were isolated by intensive perfusion the graft, subject to flow cytometry and to quantitative RT-PCR. About 34 million leukocytes accumulated in allograft vessels, but only 10 and 6 million cells in isografts and control lungs, respectively. During rejection, IFN-gamma, IL-1beta and IL-10 mRNA expression increased, IL-12 mRNA decreased, whereas IL-2, IL-6, TNF-alpha, and TGF-beta mRNA did not change. The phenotype of graft monocytes was partially activated and intravascular T-cells proliferated. In conclusion, during rejection, monocytes with unusual properties accumulate and T-lymphocytes are activated in lung allograft blood vessels.     

NF-κB signaling pathway-enhanced complement activation mediates renal injury in trichloroethylene-sensitized mice

Both NF-κB pathway and complement activation appear to be involved in kidney damage induced by trichloroethylene (TCE). However, any relationship between these two systems has not yet been established. The present study aimed to clarify the role of NF-κB in complement activation and renal injury in TCE-sensitized BALB/c mice. Mice were sensitized by an initial subcutaneous injection and repeated focal applications of TCE to dorsal skin at specified timepoints. NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) was injected (intraperitoneal) before the final two focal TCE challenges. In the experiments, mice had their blood and kidneys collected. Kidney function was evaluated via blood urea nitrogen (BUN) and creatinine (Cr) content; renal histology was examined using transmission electron microscopy (TEM). Kidney levels of phospho-p65 were assessed by Western blot and kidney mRNA levels of interleukin (IL)-1β, IL-6, IL-17, tumor necrosis factor (TNF)-α, and p65 by real-time quantitative PCR. Presence of C3 and C5b-9 membrane attack complexes in the kidneys was evaluated via immunohistochemistry. The results showed there was significant swelling, vacuolar degeneration in mitochondria, shrinkage of microvilli, disappearance of brush borders, segmental foot process fusion, and glomerular basement membrane thickening (or disrobing) in kidneys from TCE-sensitized mice. In conjunction with these changes, serum BUN and Cr levels were increased and IL-1β, IL-6, IL-17, and TNFα mRNA levels were elevated. Levels of p65 and phospho-p65 protein were also up-regulated, and there was significant C3 and C5b-9 deposition. PDTC pretreatment attenuated TCE-induced up-regulation of p65 and its phosphorylation, complement deposition, cytokine release, and renal damage. These results provide the first evidence that NF-κB pathway has an important role in TCE-induced renal damage mediated by enhanced complement activation in situ.