NODs信号通路在RAW264.7细胞抗烟曲霉菌刺激中的作用

【目的】通过培养RAW264.7细胞,并运用siRNA沉默NOD2基因来研究NODs信号通路在体外抗烟曲霉中的作用。【方法】体外培养RAW264.7细胞,接种2×105个/孔细胞于六孔板中,分为正常对照组(N)和正常沉默组[NOD2(RNAi),正常+烟曲霉孢子刺激组(N+Af)和正常沉默+烟曲霉孢子刺激组[NOD2(RNAi)+Af],每组三复孔。通过RT-PCR法检测细胞中NOD1、NOD2、RIP2 mRNA表达;Western blot法检测细胞中分泌蛋白TNF-α表达。【结果】与N组比较,N+Af组NOD1、NOD2 mRNA和TNF-α蛋白表达显著上升。与阴性对照组(Nctrol)相比,NOD2(RNAi)组NOD2 mRNA表达明显受到抑制,沉默效果达到80%以上,说明RAW264.7细胞中NOD2基因被成功沉默。与NOD2(RNAi)组比较,NOD2(RNAi)+Af组NOD1、RIP2 mRNA和TNF-α蛋白表达小幅上升,但无显著性差异(P>0.05)。与NOD2基因沉默前比较发现:与N组比较,NOD2(RNAi)组,TNF-α蛋白表达显著性升高(P<0.05)。与N+Af组比较,NOD2(RNAi)+Af组,TNF-α蛋白显著性降低(P<0.05);NOD1、RIP2 mRNA在各组中表达均未见显著性差异。【结论】NODs信号通路在RAW264.7细胞抗烟曲霉中发挥作用,尤以NOD2的作用较突出。     

胞浆识别受体NODs及其信号通路在侵袭性肺曲霉病中的作用

【目的】研究天然免疫系统中胞浆识别受体NODs及其信号通路在小鼠侵袭性肺曲霉病(IPA)中的作用。【方法】小鼠随机分为正常对照组、正常+接种烟曲霉菌组(正常感染组)和免疫抑制+接种烟曲霉菌组(IPA组),经鼻吸入烟曲霉孢子后在不同时相点处死小鼠,无菌取肺组织分别进行病理切片,烟曲霉菌落计数,RT-PCR法、Western blot法动态检测小鼠感染烟曲霉菌过程中肺组织NOD1、NOD2、RIP2 mRNA表达,促炎细胞因子TNF-α含量的变化规律。【结果】鼻吸入烟曲霉菌后72 h时,IPA组肺组织出现严重炎症反应,并有大量的菌丝生成,同时各时相点的烟曲霉菌负荷均高于正常感染组;与正常感染组比较,IPA组NOD1、RIP2 mRNA持续低表达,而NOD2 mRNA则在感染最早期(24 h)异常高表达,而在随后的感染过程中一直处于低表达状态;正常小鼠感染烟曲霉菌后,肺组织中促炎细胞因子TNF-α在感染前期皆呈高表达,且最高表达量均出现在48 h或72 h,之后下降并恢复至正常水平。而IPA小鼠促炎症细胞因子TNF-α缓慢且低水平释放。【结论】NOD1、RIP2的表达受到长期抑制,NOD2在感染最早期的过度激活以及随后的抑制表达,引起促炎细胞因子低表达,可能导致了侵袭性肺曲霉的发生发展。     

烟曲霉孢子对肥大细胞活化作用的研究

目的研究烟曲霉孢子对人肥大细胞系HMC-1的活化作用。方法用加热灭活的方法制备烟曲霉孢子抗原,体外培养人肥大细胞系HMC-1细胞,检测热灭活烟曲霉孢子诱导HMC-1细胞脱颗粒β-氨基己糖苷酶释放比,酶联免疫吸附测定(ELISA)法检测HMC-1细胞培养上清中白细胞介素-5(IL-5)的释放,Realtime-PCR检测热灭活烟曲霉孢子诱导的HMC-1细胞IL-5mRNA的表达变化。结果与阴性对照组相比,热灭活烟曲霉孢子刺激后HMC-1细胞的β-氨基己糖苷酶释放比升高[(11.3%±1.2%)VS(0.5%±0.1%),P0.05],IL-5释放增加[(11.96±1.09)VS(9.00±1.36),P0.05],IL-5mRNA表达上调[(2.47±0.12)VS(0.00±0.26),P0.05]。结论热灭活烟曲霉孢子诱导HMC-1肥大细胞活化,引起细胞活化脱颗粒、合成和释放IL-5增加。     

板蓝根对内毒素致HL-60细胞释放TNF-α和IL-8的影响

目的:探讨板蓝根抗内毒素活性部位对内毒素(LPS)致HL-60细胞释放肿瘤坏死因子(TNF-α)和白细胞介素8(IL-8)的影响.方法:MTT法确定最适细胞浓度和供试液浓度;ELISA法定量检测LPS预刺激、板蓝根预刺激、LPS与板蓝根同时刺激等三种给药方式作用后TNF-α和IL-8的浓度,观察三种给药方式对内毒素诱导TNF-α、IL-8释放的抑制强度.结果:细胞密度在0.25～2×105cell·mL-1范围时,吸光度与细胞数呈良好的线性关系;供试液无毒界限为7.812mg·mL-1;三种给药方式均能显著抑制LPS诱导HL-60细胞释放TNF-α和IL-8,其中供试液与LPS共育时抑制作用最强.结论:板蓝根可能通过抑制炎性因子过度释放发挥其抗内毒素作用.     

细菌脂多糖诱导人单核细胞株对细菌脂蛋白的耐受性及其与肌动蛋白骨架关系

细菌脂多糖(LPS)可诱导宿主对LPS的耐受,但对细菌脂蛋白(BLP)是否存在交叉耐受,目前报道不一。采用人单核细胞株(THP-1),建立小剂量LPS诱导THP-1对LPS耐受的细胞模型;观察细胞肌动蛋白骨架、炎症因子TNF-α、IL-1β、IL-6的浓度及NF-κB的DNA结合活力的变化情况;探讨BLP交叉耐受及细胞骨架在其中的作用。结果显示,THP-1细胞经小剂量(10ng/ml)LPS、大剂量(100ng/ml)LPS或BLP刺激后,细胞形态严重变形,肌动蛋白重组,细胞周边肌动蛋白丝带消失,出现明显的肌动蛋白收缩团块及伪足,细胞核内NF-κB的DNA结合活性显著升高,培养上清液中炎症因子(TNF-α、IL-1β及IL-6)的释放显著增加;而小剂量LPS预刺激12h后,再用大剂量的LPS或BLP刺激6h,上述指标明显改善;采用细胞骨架肌动蛋白聚集破坏剂鬼笔环肽预处理后的THP-1细胞,可取消由小剂量LPS诱导的自身耐受及对BLP的交叉耐受;可见,细菌LPS、BLP(100ng/ml)可诱导THP-1细胞肌动蛋白骨架的改变,激活NF-κB信号通路,诱导炎性细胞因子TNF-α、IL-1、IL-6过度释放,激活宿主炎症细胞的炎症反应;而小剂量LPS预刺激后可诱导出THP-1细胞对LPS的自身耐受和对BLP的交叉耐受;细胞骨架肌动蛋白参与了小剂量LPS诱导THP-1细胞对LPS自身耐受和对BLP交叉耐受的形成。     

EGb761对LPS诱导THP-1细胞释放HMGB1蛋白表达的调节

目的:探讨EGb761对LPS诱导THP-1细胞释放HMGB1蛋白表达的调节,为EGb761的临床运用提供可行的依据。方法:LPS(1μg/m L)诱导不同时间后,western blotting检测THP-1细胞上清液中HMGB1蛋白含量变化及不同浓度EGb761对LPS诱导THP-1细胞释放HMGB1蛋白的表达和NF-κB的活性;酶联免疫吸附法(ELISA)检测细胞中IL-1β、IL-6、TNF-α的含量。共聚焦显微镜观察EGb761对LPS诱导THP-1细胞释放HMGB1蛋白核转位变化。结果:(1)LPS组IL-1β、IL-6、TNF-α的含量在刺激6-12 h后明显高于空白对照组,而EGb761+LPS组IL-1β、IL-6、TNF-α的含量均显著低于LPS组(P0.05)。(2)EGb761处理LPS诱导THP-1细胞6 h后细胞上清液NF-κB活性表达量较空白对照组低,随着处理时间延长至12 h,NF-κB的活性表达量呈明显下降趋势(P0.05)。(3)LPS诱导THP-1细胞18 h后,细胞上清液中HMGB1蛋白含量呈明显升高趋势(P0.05)。(4)不同浓度EGb761对LPS诱导THP-1细胞18 h后,HMGB1蛋白含量较空白对照组有下降趋势,HMGB1蛋白含量随着EGB761浓度增加至100μg/m L呈下降趋势并呈浓度依赖效应(P0.05)。(5)LPS诱导THP-1细胞后,在共聚焦显微镜下可见胞浆中大量HMGB1蛋白标记分布,而EGb761+LPS共同诱导THP-1细胞后胞浆中可见少量HMGB1蛋白分布。结论:LPS可诱导THP-1细胞IL-1β、IL-6、TNF-α表达增多及NF-κB活化,导致HMGB1蛋白表达增多及核转位,而EGB761能抑制THP-1细胞IL-1β、IL-6、TNF-α表达及NF-κB活化,调节HMGB1蛋白的表达及核转位。     

黄芩苷对脂多糖诱导的巨噬细胞NF-κB活化和炎症因子表达的影响

目的:研究黄芩苷对脂多糖(LPS)诱导小鼠巨噬细胞核因子κB(NF-κB)及肿瘤坏死因子α(TNF-α)、白介素6(IL-6)表达的影响.方法:分别用LPS(终浓度1μgomL-1)和LPs+黄芩苷(终浓度10,50,100μmol moloL-1)处理生长良好的小鼠巨噬细胞RAW264.7,用RT-PCR法和Elisa法检测细胞及其上清液中TNF-α、IL-6 mRNA和蛋白的表达变化,用Western Blot法检测细胞核内NF-κB p65蛋白含量变化.结果:LPS刺激RAW264.7细胞可导致NF-κB激活,上调TNF-α、IL-6表达;黄芩苷预处理能降低LPS诱导的NF-κB出活化和TNF-α、IL-6表达.结论:黄芩苷可通过抑制NF-κB活化,下调LPS诱导的巨噬细胞TNF-α、IL-6的生成,发挥抗炎作用.这可能是其抗动脉粥样硬化的作用机制之一.     

适宜浓度短链脂肪酸混合物对小胶质细胞炎症 抑制及机制研究

本研究的主要目的是探讨适宜浓度短链脂肪酸(short chain fatty acids,SCFAs)混合物对炎症环境下小胶质细胞的抑炎作用及其机制.采用脂多糖(LPS)刺激小鼠小胶质细胞系BV-2细胞建立神经炎症模型,并利用CCK8试剂盒检测不同浓度单一的乙酸钠、丙酸钠、丁酸钠处理后的细胞活力.设计选取这三种SCFAs对细胞活力无影响、且有抑炎效果的特定浓度进行组合(SCFAs mix),进一步检测SCFAs mix对LPS刺激下BV-2细胞炎症反应的影响及机制,包括:a.用一氧化氮(NO)试剂盒检测NO的释放;b.用ELISA检测炎症因子TNF-α、IL-6的释放;c.用qRT-PCR和Western blot检测炎症因子TNF-α、IL-6、炎症小体NLRP3、炎症通路相关蛋白TLR4、NF-κB等的表达变化.结果表明LPS刺激BV-2细胞4 h后,在体系中添加特定浓度的单一SCFA处理12 h后,不能缓解BV-2细胞的炎症反应,而将上述SCFAs配制成同等终浓度的SCFAs mix处理12 h却能显著降低细胞培养上清液中NO、TNF-α和IL-6 (均P0.001)的量,还能抑制BV-2细胞内iNOS、TNF-α、IL-6和NLRP3 mRNA的升高(均P0.001);通过对炎症信号通路关键分子的检测发现,SCFAs mix可以抑制LPS诱导的BV-2细胞内TLR4、MyD88、TRAF6和NF-κB蛋白的表达升高.综上可见:适宜浓度的混合SCFAs可通过调控TLR4/MyD88/TRAF6/NF-κB炎症通路抑制LPS诱导的小胶质细胞的炎症反应,而起到抗炎的保护作用.     

SCARF1 在人THP-1 单核源性巨噬细胞抗烟曲霉菌刺激中的作用

目的:运用干扰腺病毒沉默THP1细胞中SCARF1基因研究其在体外抗烟曲霉中的作用。方法:用灭活的烟曲霉分生孢子(1×105 CFU/m L)于不同时间点处理THP-1细胞,RT-PCR分别检测SCARF1和TNF-αm RNA的表达;将Ad-si RNA-SCARF1转导细胞24 h后给予烟曲霉孢子刺激24 h,通过RT-PCR法检测细胞中TNF-αm RNA表达,Western blot法检测细胞中SCARF1表达以及NF-κB通路相关信号分子的活性。结果:RT-PCR证实烟曲霉孢子刺激能时间依赖性增强THP1细胞中SCARF1和TNF-α表达;Western法证实与Ad-GFP组比较Ad-si RNA-SCARF1组SCARF1的表达量显著降低(P0.05),沉默效率为71%;与Ad-GFP组比较,Ad-GFP+Af组NF-κB亚单位p65的磷酸化水平明显升高(P0.05),在Ad-si RNA-SCARF1+Af组,磷酸化p65的产生明显减少,SCARF1沉默后细胞因子TNF-α的分泌明显减少。结论:烟曲霉孢子刺激能诱导巨噬细胞SCARF1的表达增加,诱导信号分子NF-κB的活化,导致相应的细胞因子分泌增加,从而在巨噬细胞抗烟曲霉中发挥作用。     

球形孢子丝菌刺激小鼠树突状细胞表达前炎症细胞因子的研究

目的本研究旨在观察分离于新疆的球形孢子丝菌临床株刺激小鼠树突状细胞(Dendritic cells,DCs)后不同炎症因子分泌表达的特征,初步预测这些炎症因子的功能。方法菌株来源于淋巴管型孢子丝菌病患者。将该菌配置成不同浓度的菌悬液(1×10~4个/mL～1×10~7个/mL),刺激小鼠DC(细胞悬浮液浓度1×10~6细胞/mL),分别收集6 h、24 h、48 h、72 h时细胞培养上清液,采用酶免法检测IL-1β、IL-6、IL-4、TNF-α、IFN-γ的含量表达。结果以最低浓度菌液(1×10~4个/mL)刺激DC,被刺激后的DC分泌了IL-1β、IL-6和TNF-α,不同时间点分泌量分别为:IL-1β(6 h:21.26±3.03;24 h:24.04±4.25;48 h:24.90±4.31;72 h:27.29±6.09)、IL-6(6 h:44.38±3.73;24 h:101.72±12.28;48 h:133.10±8.67;72 h:180.38±13.84)、TNF-α(6 h:860.36±20.64;24 h:356.03±11.46;48 h:457.43±17.39;72 h:1454.53±19.46),但是IFN-γ和IL-4未见分泌表达。IL-1β和IL-6分泌水平有随时间和剂量依赖而逐渐增高,但是TNF-α释放量呈现不规律表达。结论 DC参与了球形孢子丝菌感染的天然免疫应答,分泌的关键炎症因子是IL-1β、IL-6、和TNF-α,表达量为TNF-α IL-6 IL-1β。其中IL-1β和IL-6分泌表达量具有时间和剂量依赖性。     

Peroxiredoxin-1, a possible target in modulating inflammatory cytokine production in macrophage like cell line RAW264.7

Peroxiredoxin (PRX), a scavenger of H₂O₂ and alkyl hydroperoxides in living organisms, protects cells from oxidative stress. Contrary to its known anti‐oxidant roles, the involvement of PRX‐1 in the regulation of lipopolysaccharide (LPS) signaling is poorly understood, possible immunological functions of PRX‐1 having been uncovered only recently. In the present study, it was discovered that the PRX‐1 deficient macrophage like cell line (RAW264.7) has anti‐inflammatory activity when stimulated by LPS. Treatment with LPS for 3 hrs resulted in increased gene expression of an anti‐inflammatory cytokine, interleukin‐10 (IL‐10), in PRX‐1 knock down RAW264.7 cells. Gene expression of pro‐inflammatory cytokines IL‐1β and tumor necrosis factor‐ α (TNF‐α) did not show notable changes under the same conditions. However, production of these cytokines significantly decreased in PRX‐1 knock down RAW264.7 cells with 12 hrs of stimulation. Production of IL‐10 was also increased in PRX‐1 knock down RAW264.7 cells with 12 hrs of stimulation. We predicted that higher concentrations of IL‐10 would result in decreased expression of IL‐1β and TNF‐α in PRX‐1 knock‐down cells. This was confirmed by blocking IL‐10, which reestablished IL‐1β and TNF‐α secretion. We also observed that increased concentrations of IL‐10 do not affect the NF‐κB pathway. Interestingly, STAT3 phosphorylation by LPS stimulation was significantly increased in PRX‐1 knockdown RAW264.7 cells. Up‐regulation of IL‐10 in PRX‐1 knockdown cells and the resulting downregulation of proinflammatory cytokine production seem to involve the STAT3 pathway in macrophages. Thus, down‐regulation of PRX‐1 may contribute to the suppression of adverse effects caused by excessive activation of macrophages through affecting the STAT3 signaling pathway.     

Macrophage-adipocyte interaction: marked interleukin-6 production by lipopolysaccharide

Objective: Recent studies suggested macrophages were integrated in adipose tissues, interacting with adipocytes, thereby exacerbating inflammatory responses. Persistent low‐grade infection by gram‐negative bacteria appears to promote atherogenesis. We hypothesized a ligand for toll‐like receptor 4 (TLR4), bacterial lipopolysaccharide (LPS), would further exaggerate macrophage‐adipocyte interaction. Research Methods and Procedures: RAW264.7 macrophage cell line and differentiated 3T3‐L1 preadipocytes were co‐cultured using transwell system. As a control, each cell was cultured independently. After incubation of the cells with or without Escherichia coli LPS, tumor necrosis factor (TNF)‐α and interleukin (IL)‐6 production was evaluated. Results: Co‐culture of macrophages and adipocytes with low concentration of Escherichia coli LPS (1 ng/mL) markedly up‐regulated IL‐6 production (nearly 100‐fold higher than that of adipocyte culture alone, p < 0.01), whereas TNF‐α production was not significantly influenced. This increase was partially inhibited by anti‐TNF‐α neutralizing antibody. Recombinant TNF‐α and LPS synergistically up‐regulated IL‐6 production in adipocytes. However, this increase did not reach the level of production observed in co‐cultures stimulated with LPS. Discussion: A ligand for TLR‐4 stimulates macrophages to produce TNF‐α. TNF‐α, thus produced, cooperatively up‐regulates IL‐6 production with other soluble factors secreted either from adipocytes or macrophages in these cells. Markedly up‐regulated IL‐6 would greatly influence the pathophysiology of diabetes and its vascular complications.     

Tumor necrosis factor release from lipopolysaccharide-stimulated human monocytes: Lipopolysaccharide tolerance in vitro

Human peripheral blood monocytes secrete tumor necrosis factor (TNF) in response to stimulation with bacterial lipopolysaccharide (LPS). We have shown that isolated human monocytes pretreated with LPS for 24 h secrete lower levels of TNF on a second stimulation with LPS than monocytes that have been stimulated with a single dose of LPS either immediately after isolation or 24 h after isolation. The levels of TNF released by monocytes after the second stimulation with LPS are proportional to the LPS concentration over a range from 1 ng/mL to 10 micrograms/mL. Increasing concentrations of LPS used during the first 24-h stimulation induce greater suppression of TNF release after a second stimulation with LPS. After an initial stimulus of 10 micrograms/mL LPS, a second stimulation of monocytes even with 10 micrograms/mL LPS will result in TNF secretion similar to that of unstimulated cells. This in vitro tolerance apparently can be overcome by stimulating previously activated cells with phorbol myristate acetate. We have also shown that neither prostaglandin E2 nor dexamethasone added during the initial stimulation with LPS had an effect on the subsequent reduction in TNF release on a second stimulation of monocytes with LPS.     

Age‐0 striped bass,Morone saxatilis (Walbaum, 1792), response to immunostimulation

Young‐of‐the‐year (age‐0) striped bass, Morone saxatilis, were studied to characterize their responses to inflammatory stimuli. There were two studies, with the hypotheses that (i) <5 g striped bass would respond to inflammatory insult within 6 h, and (ii) response to antigens would be maintained for >24 h in larger fish. Study I was conducted to understand the cytokine expression pattern (IL‐1β, TNF‐α, Nramp and TGF‐β) in response to lipopolysaccharide (LPS) or Freund's complete adjuvant (FCA) stimulation in age‐0 striped bass (3.44 ± 1.68 g, 70.6 ± 10.3 mm fork length) up to 24 h post injection (hpi). Study II was similar to Study I, but striped bass were sampled over a longer time frame (by 48 hpi) and larger age‐0 striped bass were used (20.6 ± 5.9 g, 129.2 ± 10.9 mm fork length). It was confirmed that immunostimulants such as LPS and FCA induce production of inflammatory cytokines and Nramp, which are important in innate immune response to bacterial infection. The responses were rapidly stimulated with LPS (IL‐1β, TNF‐α, TGF‐β >3‐fold increase, compared to PBS) or FCA (IL‐1β >3‐fold and TGF‐β >2‐fold, compared to PBS) within 6 hpi and maintained in most cases 48 hpi (spleen Nramp and TGF‐β 2‐fold >PBS, at 24 and 48 h), similar to other teleosts. Intraperitoneal injection with PBS also simulated inflammatory gene expression, but was delayed (IL‐1β, TNF‐α, TGF‐β and Nramp, FCA and LPS< at 6 h; 24 h >LPS and PBS) in comparison to LPS and FCA, suggesting that this procedure and possibly the volume used can be stimulatory and potentially harmful in age‐0 fish. Therefore, this study suggests that age‐0 striped bass are capable of strong cytokine induction in response to immunological stimulation within a very short period of time.     

Extracellular heat shock protein-70 induces endotoxin tolerance in THP-1 cells

Recent data suggest that heat shock protein-70 (HSP-70), an intracellular protein, can exist in the extracellular compartment and signal through the CD14/TLR4 pathway. In this study, we tested the hypothesis that extracellular HSP-70 induces endotoxin (LPS) tolerance. Using human monocyte cell line (THP-1), initial dose-response experiments were conducted to determine a subthreshold concentration of HSP-70 that does not induce NF-kappaB activity. Differentiated THP-1 cells were preconditioned with subthreshold concentration (0.03 microg/ml HSP-70) for 18 h, followed by LPS stimulation (1 microg/ml) for 4 h. Preconditioning with HSP-70 decreased subsequent LPS-mediated NF-kappaB-dependent promoter activity and was accompanied by significant decreases of supernatant TNF levels. Furthermore, human monocytes isolated from human volunteers, subsequently preconditioned with HSP-70, demonstrated LPS tolerance as evidenced by abrogated supernatant TNF levels. Additional experiments were conducted to exclude the possibility of endotoxin contamination of HSP-70 by boiling HSP-70 at 100 degrees C for 1 h or preconditioning with equivalent concentrations of endotoxin as present in the HSP-70 preparation. These experiments indicated that induction of tolerance was not secondary to endotoxin contamination. Neutralization experiments with an anti-HSP-70 Ab confirmed the specificity of HSP-70 in tolerance induction. Preconditioning with HSP-70 attenuated cytosolic degradation of inhibitor kappaB-alpha and inhibited activation of inhibitor kappaB kinase following LPS stimulation. HSP-70 preconditioning decreased phosphorylation of the p65 subunit of NF-kappaB following LPS stimulation. These data suggest a novel role for extracellular HSP-70 in modifying mononuclear cell responses to subsequent LPS challenge.     

Tanshinone IIA alleviates lipopolysaccharide‐induced acute lung injury by downregulating TRPM7 and pro‐inflammatory factors

The study aimed to investigate the role of Tanshinone IIA (Tan IIA) in lipopolysaccharide (LPS)‐induced acute lung injury (ALI) in its regulation of TRPM7. Wistar male rats were randomly divided into the normal saline (NS), LPS, knockout (KO) + LPS, low‐dose Tan IIA (Tan‐L), middle‐dose Tan IIA (Tan‐M), high‐dose Tan IIA (Tan‐H) and KO + high‐dose Tan IIA (KO + Tan‐H) groups. The level of tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐1β, IL‐6, TRPM7 protein expression, current density‐voltage curve and Ca²⁺ concentration were detected through ELISA, Western blotting, electrophysiological experiment and a calcium‐imaging technique, respectively. The rats in the KO + LPS, Tan‐L, Tan‐M, Tan‐H and KO + Tan‐H groups all displayed lower levels of TNF‐α, IL‐1β and IL‐6 than the LPS group. Rats in the KO + Tan‐H group exhibited lower levels of NF‐α, IL‐1β and IL‐6 than rats in the Tan‐H group. Elevated levels of TRPM7 protein expression in the LPS and Tan groups were detected in comparison with the NS group. However, TRPM7 protein expression in Tan‐M and Tan‐H groups was notably lower than in that of the LPS group. In comparison with the NS group, the LPS and Tan groups had a greater PIMs cell density and a higher concentration of Ca²⁺. Contrary results were observed in the KO + LPS, Tan‐H and KO + Tan‐H groups. Tan IIA decreases calcium influx in PIMs and inhibits pro‐inflammatory factors which provide an alleviatory effect in regards to LPS‐induced ALI by suppressing TRPM7 expression.     

Salidroside suppressing LPS‐induced myocardial injury by inhibiting ROS‐mediated PI3K/Akt/mTOR pathway in vitro and in vivo

The purpose of the present study was to investigate the effect of salidroside (Sal) on myocardial injury in lipopolysaccharide (LPS)‐induced endotoxemic in vitro and in vivo. SD rats were randomly divided into five groups: control group, LPS group (15 mg/kg), LPS plus dexamethasone (2 mg/kg), LPS plus Sal groups with different Sal doses (20, 40 mg/kg). Hemodynamic measurement and haematoxylin and eosin staining were performed. Serum levels of creatine kinase (CK), lactate dehydrogenase, the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH‐px), glutathione, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), and interleukin‐1β (IL‐1β) were measured after the rats were killed. iNOS, COX‐2, NF‐κB and PI3K/Akt/mTOR pathway proteins were detected by Western blot. In vitro, we evaluated the protective effect of Sal on rat embryonic heart‐derived myogenic cell line H9c2 induced by LPS. Reactive oxygen species (ROS) in H9c2 cells was measured by flow cytometry, and the activities of the antioxidant enzymes CAT, SOD, GSH‐px, glutathione‐S‐transferase, TNF‐α, IL‐6 and IL‐1β in cellular supernatant were measured. PI3K/Akt/mTOR signalling was examined by Western blot. As a result, Sal significantly attenuated the above indices. In addition, Sal exerts pronounced cardioprotective effect in rats subjected to LPS possibly through inhibiting the iNOS, COX‐2, NF‐κB and PI3K/Akt/mTOR pathway in vivo. Furthermore, the pharmacological effect of Sal associated with the ROS‐mediated PI3K/Akt/mTOR pathway was proved by the use of ROS scavenger, N‐acetyl‐l ‐cysteine, in LPS‐stimulated H9C2 cells. Our results indicated that Sal could be a potential therapeutic agent for the treatment of cardiovascular disease.     

Sodium salicylate modulates inflammatory responses through AMP‐activated protein kinase activation in LPS‐stimulated THP‐1 cells

Sodium salicylate (NaSal) is a nonsteroidal anti‐inflammatory drug. The putative mechanisms for NaSal's pharmacologic actions include the inhibition of cyclooxygenases, platelet‐derived thromboxane A2, and NF‐κB signaling. Recent studies demonstrated that salicylate could activate AMP‐activated protein kinase (AMPK), an energy sensor that maintains the balance between ATP production and consumption. The anti‐inflammatory action of AMPK has been reported to be mediated by promoting mitochondrial biogenesis and fatty acid oxidation. However, the exact signals responsible for salicylate‐mediated inflammation through AMPK are not well‐understood. In the current study, we examined the potential effects of NaSal on inflammation‐like responses of THP‐1 monocytes to lipopolysaccharide (LPS) challenge. THP‐1 cells were stimulated with or without 10 ug/mL LPS for 24 h in the presence or absence of 5 mM NaSal. Apoptosis was measured by flow cytometry using Annexin V/PI staining and by Western blotting for the Bcl‐2 anti‐apoptotic protein. Cell proliferation was detected by EdU incorporation and by Western blot analysis for proliferating cell nuclear antigen (PCNA). Secretion of pro‐inflammatory cytokines (TNF‐α, IL‐1β, IL‐6) was determined by enzyme‐linked immunosorbent assay (ELISA). We observed that the activation of AMPK by NaSal was accompanied by induction of apoptosis, inhibition of cell proliferation, and increasing secretion of TNF‐α and IL‐1β. These effects were reversed by Compound C, an inhibitor of AMPK. In addition, NaSal/AMPK activation inhibited LPS‐induced STAT3 phosphorylation, which was reversed by Compound C treatment. We conclude that AMPK activation is important for NaSal‐mediated inflammation by inducing apoptosis, reducing cell proliferation, inhibiting STAT3 activity, and producing TNF‐α and IL‐1β.