天山堇菜提取物基于NLRP3/caspase-1/IL-1β信号通路改善哮喘小鼠气道炎症的作用及机制

目的 探究天山堇菜提取物(Viola tianshanica Maximextract, VTME)改善哮喘小鼠气道炎症的作用及机制。方法 BALB/c雌性小鼠,随机分为正常对照组、卵清白蛋白(OVA)模型组、VTME低、中、高剂量(80、160、320 mg·kg^-1)组、阳性对照药地塞米松组(Dex, 80 mg·kg^-1)组。采用OVA致敏、激发的方法诱导哮喘模型。收集小鼠肺泡灌洗液(BALF)并对炎症细胞进行分类计数;采用ELISA法检测BALF中调节活化的正常T细胞表达和分泌因子(RANTES)、IFN-γ及TNF-α含量,肺组织中TNF-α、MCP-1、IFN-γ、IL-17含量以及血清中IgE、嗜酸性粒细胞趋化因子(eotaxin)水平;采用HE染色观察肺组织病理改变;采用qRT-PCR法和Western blot法分别检测肺组织NLRP3 mRNA表达水平及GSDMD、caspase-1、IL-1β、NLRP3蛋白表达水平。结果 VTME能明显降低哮喘小鼠BALF中各类炎症细胞数量及TNF-α、IFN-γ、Rantes的含量,...     

隐丹参酮通过TWEAK/Fn14和TGF-β1/Smads信号通路缓解OVA诱导哮喘小鼠气道炎症

目的探究隐丹参酮对哮喘小鼠气道重塑模型的治疗作用,以及其机制是否与TWEAK/Fn14和TGF-β1/Smads信号通路相关。方法选取♀BALB/c小鼠40只,分为5组(每组8只),分别为control组、OVA模型组、隐丹参酮低、高剂量组(20、40 mg·kg~(-1))、地塞米松阳性对照组(1 mg·kg-1)。HE及PAS染色法观察小鼠肺组织的炎症情况及杯状细胞变化; Diff-Quick染色法对小鼠BALF中各类细胞计数; ELISA法检测小鼠BALF中炎性及促炎细胞因子的含量; Western blot检测肺组织TWEAK、Fn14、TGF-β1、Smad2/3、Smad4表达;免疫组化法检测小鼠肺组织中TWEAK、TGF-β1的表达水平。结果隐丹参酮能减少OVA诱导的炎症细胞渗出及杯状细胞增生;隐丹参酮抑制哮喘小鼠BALF中总细胞及EOS、NEU、LYM的生成,并降低促炎细胞因子的水平; Western blot结果显示,隐丹参酮抑制TWEAK、Fn14、TGF-β1、Smad2/3、Smad4的蛋白表达;免疫组化结果显示,隐丹参酮可减少肺组织中TWEAK、TGF-β1蛋白表达。结论隐丹参酮通过TWEAK/Fn14和TGF-β1/Smads信号通路改善OVA诱导的小鼠气道炎症。     

牛蒡子苷元通过抑制PI3-K/Akt信号通路诱导肝癌细胞凋亡

目的 探讨天然木脂素类化合物牛蒡子苷元对肝癌细胞生长的抑制作用及其可能机制。方法 采用不同浓度的牛蒡子苷元处理HepG2 和Hep3B 细胞,通过MTT 法检测细胞增殖情况,流式细胞术检测细胞凋亡及细胞周期,免疫印迹检测细胞中caspase-9 和caspase-3 的活化情况以及抗凋亡蛋白的表达。进一步通过转染Akt 质粒以及使用PI3K 抑制剂,探讨牛蒡子苷元对肝癌细胞PI3K/Akt 信号通路的影响。结果 牛蒡子苷元能以浓度依赖性方式显著抑制肝癌细胞增殖并促进其凋亡,同时抑制肝癌细胞中PI3K/Akt 信号通路活化,降低抗凋亡蛋白Bcl-xL、Mcl-1 和survivin 的表达,抑制mTOR 和S6K 的磷酸化;细胞过表达Akt 活化蛋白后可抑制牛蒡子苷元的上述效应,而PI3K 抑制剂联合作用可增强上述效应。结论 牛蒡子苷元可通过抑制PI3K/Akt 信号通路下调抗凋亡蛋白的表达进而促进肝癌细胞凋亡。     

荆芥挥发油抗内毒素中毒小鼠NLRP3炎症小体通路的机制研究

目的以NLRP3炎症小体通路为切入点,探究荆芥挥发油抗炎效应的分子机制。方法荆芥挥发油低、高剂量(0.226、0.452 g·kg~(-1))连续灌胃给药5 d,末次给药后30 min,小鼠腹腔注射LPS (0.015 g·kg~(-1),10 mL·kg~(-1))构建内毒素中毒小鼠模型,造模后12 h取材,测定相关指标。Griess法测定肺组织NO含量;qPCR法检测肺组织中NLRP3、ASC、caspase-1、IL-1β、iNOS、p65 mRNA的表达;免疫组化法检测肺组织中P2X7R、Cathepsin B的表达;Western blot法测定肺组织中NLRP3、caspase-1(p20)、pro-IL-1β、COP1蛋白表达。结果 0.226 g·kg~(-1)荆芥挥发油明显降低模型小鼠肺组织Cathepsin B、NLRP3蛋白表达;0.452 g·kg~(-1)荆芥挥发油明显降低模型小鼠肺组织中NO水平,明显下调小鼠肺组织中NLRP3、iNOS、p65、IL-1βmRNA的表达及P2X7R蛋白表达;荆芥挥发油(0.226、0.452 g·kg~(-1))均能明显下调caspase-1(p20)蛋白水平,升高COP1蛋白水平。结论荆芥挥发油对内毒素中毒小鼠的保护作用与其抗炎效应密切相关,抗炎机制与抑制NLRP3炎症小体的激活有关。     

热打击通过活化NLRP3炎性小体增加肺毛细血管的通透性

目的 验证热打击通过活化 NLRP3炎性小体增加肺毛细血管通透性的机制。方法 C57BL/6小鼠和肺微血管内皮细胞,用 42 ℃热打击。体内实验分组包括：对照组和热打击组,每组 12只小鼠;体外实验分组包括：对照组、热打击组、热打击+2,2,6,6-四甲基哌啶氧化物（TEMPO）组、热打击+半胱氨酸的天冬氨酸蛋白水解酶（caspase）抑制剂（Z-VAD-FMK）组、热打击+白细胞介素-1受体拮抗剂（IL-1Ra）组,每组 4例。检测肺组织和肺微血管内皮细胞活性氧（ROS）表达;Western blot 和（或）免疫荧光检测 caspase-1、白细胞介素-1β（IL-1β）、紧密连接蛋白 ZO-1、occludin、claudin-5的表达;用伊文氏蓝检测小鼠肺毛细血管的通透性。结果 体内实验结果显示,与对照组比较,热打击组小鼠肺组织伊文氏蓝浓度明显升高、ROS表达上调、NLRP3炎性小体活化、IL-1β表达上调和紧密连接蛋白的表达下调（P＜0.01）。体外实验结果显示,用 TEMPO 清除 ROS 后,NLRP3炎性小体活化被抑制（P＜0.01）;用 ZVAD-FMK抑制 caspase-1作用后,IL-1β表达显著下调（P＜0.01）;用 IL-1Ra阻断 IL-1β作用后,紧密连接蛋白表达显著上调（P＜0.01）。结论 热打击可通过活化 NLRP3炎性小体促进 IL-1β的表达,进而下调紧密连接蛋白的表达,导致肺微血管通透性增加。     

儿茶素抑制NF-κB-TSLP通路缓解过敏性哮喘小鼠炎症反应

目的探讨儿茶素(catechin)对过敏性哮喘小鼠炎症反应的治疗作用及其机制。方法采用BALB/c♀小鼠建立鸡卵清蛋白(OVA)致敏和激发的过敏性哮喘模型,给药组分别给予儿茶素(75、150、300 mg·kg^-1)干预。记录外周血白细胞分类及计数;HE染色观察肺组织病理学改变;ELISA法检测血清OVA特异性Ig E水平及肺组织TSLP、IL-5、IL^-13的含量;Western blot检测肺组织NF-κB p65、IκB蛋白表达情况;免疫荧光检测NF-κB p65核转录情况。结果儿茶素可明显减少外周血白细胞总数,降低血清OVA特异性Ig E含量,减少肺组织中TSLP以及Th2型炎症因子IL-5、IL^-13的含量,抑制NF-κB p65核转录。结论儿茶素可有效缓解OVA所致的过敏性哮喘小鼠的Th2型炎症反应,其作用可能是通过调控NF-κB通路,抑制TSLP表达而实现的。     

瓜子金皂苷己抑制IL-1β的释放及其机制研究

目的研究瓜子金皂苷己(polygalasaponin F,PS-F)对LPS诱导的BV2小胶质细胞炎症反应中炎性因子IL-1β释放的影响及其作用机制。方法实验分为空白组、LPS模型组、LPS+PS-F (0.10、1.00、10.00μmol·L~(-1))给药组。运用ELISA法检测培养液上清中IL-1β的分泌量;real-time PCR检测IL-1βmRNA的表达;Western blot检测IL-1β、NLRP3、caspase-1、ASC、caspase-11的蛋白表达量。结果 ELISA、real-time PCR和Western blot结果均表明,PS-F能有效抑制LPS诱导BV2小胶质细胞释放炎性因子IL-1β(P<0.01,P<0.05);Western blot结果表明,PS-F可以下调NLRP3、caspase-1、ASC、caspase-11的蛋白表达,其中ASC、caspase-11所得结果差异有统计学意义(P<0.05)。结论 PS-F可以有效抑制LPS诱导BV2细胞炎症反应中炎性因子IL-1β的释放,且与下调NLRP3炎性小体、抑制caspase-11的激活有关。     

骨形态构建蛋白 2型受体下调单核细胞趋化蛋白 1/CC类趋化因子受体 2通路对哮喘小鼠气道炎症和 Th1/Th2平衡的影响

目的探究骨形态构建蛋白 2型受体( BMPR2)对小鼠哮喘模型气道炎症和 Th1/Th2平衡的影响及其机制。方法2021年 9月至 2022年 11月选用 24只 C57BL/6小鼠尾静脉注射 BMPR2腺病毒,随后卵清蛋白( OVA)致敏和激发建立哮喘小鼠于模型;采用随机数字表法分为对照组(生理盐水替代 OVA造模)、 OVA模型组( OVA诱导小鼠哮喘模型)、 OVA+载体( Vector)组(空载慢病毒处理的 OVA哮喘模型小鼠)OVA+BMPR2组( BMPR2过表达慢病毒处理的 OVA哮喘模型小鼠),每组 6只。收集支气管肺泡灌洗液( BALF)和肺组织。免疫、组织化学检测肺组织 BMPR2表达水平;苏木精 -伊红染色观察肺组织病理学改变;瑞氏染色后计数 BALF中各类炎症细胞数目;酶联免疫吸附测定( ELISA)试剂盒检测 BALF中白细胞介素( IL)-4,IL-5和 IL-13炎症因子水平;蛋白质印迹法检测肺组织和气道上皮细胞 16HBE中 BMPR2、单核细胞趋化蛋白 -1(MCP1)及其受体 CC类趋化因子受体 2(CCR2)蛋白表达水平。免疫共沉淀实验检测 BMPR2与 MCP1相互作用。结果与对照组相比, OVA模型组肺组织 BMPR2(0.36±0.05比 1.04±0.04)显著降低(P<0.01);小鼠肺泡破坏程度严重,肺组织有大量的淋巴细胞浸润; BALF中炎症细胞总数［(93.25±9.32)×104个/毫升比( 4.79±0.41)×104个/毫升, P<0.001］、嗜酸性粒细胞、中性粒细胞和淋巴细胞均升高; Th1相关炎症因子 γ干扰素( IFN-γ)水平降低, Th2相关炎症因子 IL-4,IL-5和 IL-13水平升高。过表达 BMPR2可降低肺泡破坏程度和淋巴细胞浸润程度。与 OVA+Vector组相比, OVA+BMPR2组 BALF中炎症细胞总数、嗜酸性粒细胞、中性粒细胞和淋巴细胞均降低; ELISA结果表明, OVA+BMPR2组 BALF中 IFN-γ水平升高, IL-4,IL-5和 IL-13水平降低,提示过表达 BMPR2可上调 Th1百分比,下调 Th2细胞百分比。进一步研究表明, BMPR2过表达显著下调了 MCP1及其受体 CCR2的表达水平,且 BMPR2与MCP1存在相互作用。结论 BMPR2可通过下调 MCP1/CCR2通路降低哮喘小鼠气道炎症,并调节 Th1/Th2平衡。     

牛蒡子苷元与顺铂联合对人肺癌H460细胞系增殖和凋亡的影响

目的研究牛蒡子苷元与顺铂联合对人肺癌H460细胞系增殖和凋亡的影响。方法将不同浓度的牛蒡子苷元作用于肺癌H460细胞,应用MTT法测定牛蒡子苷元单独或联合顺铂对H460细胞的影响。应用Annexin V-FITC/PI双染法检测细胞凋亡。应用蛋白免疫印迹法检测切割型Caspase-3和切割型PARP的表达水平。结果与对照细胞相比较,牛蒡子苷元处理可显著抑制H460细胞增殖,并且这种抑制作用具有剂量依赖性。牛蒡子苷元在10μM时可增强顺铂介导的抑制H460细胞增殖(P<0.05)。牛蒡子苷元处理后显著诱导H460细胞凋亡发生,较对照细胞,牛蒡子苷元处理H460细胞具有更高水平的切割型caspase-3和PARP表达(P<0.05)。2和10μM顺铂处理H460细胞48h后分别诱导(8.4±1.9)%和(15.6±2.3)%细胞发生凋亡。当2μM顺铂和10μM牛蒡子苷元联合后,H460细胞发生凋亡的比率增加为(27.2±3.1)%,这表明牛蒡子苷元可增强顺铂对H460细胞凋亡的诱导作用(P<0.05)。结论牛蒡子苷元通过增强切割型caspase-3和PARP的表达,剂量依赖性地抑制H460细胞增殖和促进其凋亡。与顺铂联合后,牛蒡子苷元增强H460细胞对顺铂诱导的细胞增殖抑制和凋亡促进作用。因而,牛蒡子苷元可能在基于铂制剂抗NSCLC治疗中有临床应用价值。     

牛磺酸对小鼠酒精性肝损伤的保护作用及其作用机制的研究

目的观察牛磺酸对小鼠酒精性肝损伤的保护作用,并对其保护机制进行初步探讨。方法采用慢性乙醇灌胃法诱导小鼠酒精性肝损伤模型。将40只C57BL/6J雄性小鼠随机分为4组:对照组、模型组、牛磺酸给药组和牛磺酸单独处理组,每组小鼠10只。运用H&E染色及Masson染色观察各组小鼠肝组织形态改变情况及纤维化情况,检测各组小鼠肝组织中丙二醛(MDA)的水平,Western blot检测各组小鼠肝脏中炎症小体(NLRP3)及相关炎性因子IL-1β蛋白表达情况。利用Hep G2细胞构造肝细胞酒精性损伤模型,分为4组,对照组、模型组、牛磺酸给药组和牛磺酸单独处理组,利用DCFH-DA染色检测肝细胞活性氧(ROS)水平,利用Western blot检测各组细胞中NLRP3及IL-1β蛋白表达情况。结果与模型组相比,牛磺酸给药组小鼠肝脏组织炎症及纤维化情况明显减轻,肝组织中MDA的含量明显减少(P<0.05),肝组织中NLRP3及IL-1β蛋白表达明显降低(P <0.01)。体外实验结果显示,牛磺酸给药组细胞中ROS水平较模型组明显降低(P <0.05);Western blot结果显示,牛磺酸给药组NLRP3及IL-1β蛋白表达较模型组相比表达明显降低(P <0.01)。结论牛磺酸在一定程度上抑制小鼠酒精性肝损伤的发生及发展,其保护机制主要可能与其抑制ROS的生成及抑制NLRP3和IL-1β炎症因子的表达相关。     

Dexamethasone alleviate allergic airway inflammation in mice by inhibiting the activation of NLRP3 inflammasome

Dexamethasone (DEX) is the mainstay treatment for asthma, which is a common chronic airway inflammation disease. However, the mechanism of DEX resolute symptoms of asthma is not completely clear. Here, we aimed to analyze the effect of DEX on airway inflammation in OVA-induced mice and whether this effect is related to the inhibition of the activation of NLRP3 inflammasome. Female (C57BL/6) mice were used to establish the allergic airway inflammation model by inhalation OVA. The number of inflammatory cells in the bronchi alveolar lavage fluid (BALF) was counted by Swiss-Giemsa staining, and the contents of IL-1β, IL-18, IL-5 and IL-17 were detected by ELISA. The degree of inflammatory cells infiltration and mucous cells proliferation in lung tissue were separately observed by H&E and PAS staining. The proteins expression of NLRP3, pro-caspase-1, caspase-1, IL-1β, IL-6 and IL-17 in lung tissue were detected by Western blotting. We found that DEX significantly inhibited OVA-induced inflammatory cells infiltration, airway mucus secretion and goblet cell proliferation in mice. The total and classified numbers of inflammatory cells and the levels of IL-1β, IL-18, IL-5 and IL-17 in the BALF of the experimental group were significantly lower than those of the model group after DEX treatment. DEX also significantly inhibited the activity of NLRP3 inflammasome and reduced the protein contents of Pro-Caspase-1, Caspase-1, Capase-1/Pro-Caspase-1, IL-1β, IL-6 and IL-17 in lung tissues. Our study suggested that DEX alleviates allergic airway inflammation by inhibiting the activity of NLRP3 inflammasome and the levels of IL-1β and IL-18.     

Protective effects of ethyl acetate extracts of Rimulus Cinnamon on systemic inflammation and lung injury in endotoxin-poisoned mice

Rimulus cinnamon is the dried twig of Cinnamomum cassia Presl. It is widely used in China for the treatment of inflammatory processes, amenorrhea, and other diseases. We aimed to study the protective effects of ethyl acetate extracts of R. cinnamon (EAE) on systemic inflammation and lung injury in endotoxin-poisoned mice. EAE was administered 5 d prior to lipopolysaccharide (LPS) challenge with 15?mg/kg LPS. The administration of EAE increased the levels of interferon-γ (IFN-γ) and decreased the levels of interleukin-18 (IL-18) and tumor necrosis factor-α (TNF-α) in the serum. Additionally, EAE relieved the pathological changes in the tissues of the lungs and spleen, and significantly reduced the number of neutrophils in the lung tissues. In addition, treatment with EAE decreased the mRNA expression of the NLR family, pyrin domain-containing protein 3 (NLRP3), caspase-1, and interleukin-1β (IL-1β) in the lungs, as well as the expression of NLRP3, caspase-1 (p20), and pro-IL-1β proteins. These results demonstrated the promising anti-inflammatory effects of EAE in endotoxin-poisoned mice. Furthermore, EAE could alleviate the lung injury of endotoxin-poisoned mice by antagonizing the activation of the NLRP3 inflammasome.     

Genipin alleviates LPS-induced acute lung injury by inhibiting NF-κB and NLRP3 signaling pathways

Genipin has been reported to have anti-inflammatory effect. However, its role on lipopolysaccharide (LPS)-induced acute lung injury (ALI) has not been explored. This study aimed to evaluate the effect of genipin on murine model of acute lung injury induced by LPS. The mice were treated with genipin 1 h before LPS administration. 12 h later, the myeloperoxidase (MPO) in lung tissues and lung wet/dry ratio were detected. The levels of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured by ELISA. Apart from this, we use western blot to detect the protein expression in the NF-κB and NLRP3 signaling pathways. The results showed that the treatment of genipin markedly attenuated the lung wet/dry ratio and the MPO activity. Moreover, it also inhibited the levels of TNF-α, IL-1β, IL-6 in the BALF. In addition, genipin significantly inhibited LPS-induced NF-κB and NLRP3 activation. In conclusion, these results demonstrate that genipin protected against LPS-induced ALI through inhibiting NF-κB and NLRP3 signaling pathways.     

Rhapontin ameliorates colonic epithelial dysfunction in experimental colitis through SIRT1 signaling

Rhapontin (3, 3′, 5-trihydroxy-4′-methoxystilbene-3-O-glucoside) has anti-thrombotic, anti-allergic and anti-diabetic activities. This study aimed to assess the protective effects of rhapontin on intestinal damage in vivo and in vitro. In a dextran sodium sulfate (DSS)-induced mouse model, oral administration of rhapontin (100 mg/kg) significantly attenuated colonic pathological damage and remarkably inhibited infiltration by inflammatory cells, myeloperoxidase (MPO) activity, NLRP3 inflammasome activation and SIRT1 expression in the colon. Moreover, rhapontin prevented DSS-induced impairment in the colon epithelium barrier by increasing the expression of tight junction proteins, such as zonula occludens-1(ZO-1) and occludin, and reduced apoptosis-associated protein (cyt-c, the ratio of bcl-2/bax and cleaved-capase9) expression in the colon. The in vitro results showed that rhapontin significantly reduced NLRP3 inflammasome activation and cleaved caspase-1 expression as well as lowered IL-1β secretion in LPS-stimulated human-THP-1-derived macrophages. Further study revealed that compound EX257 (an SIRT1 inhibitor) blocked the inhibitory effects of rhapontin on NLRP3-dependent caspase-1 activation and IL-β production in activated macrophages. In addition, in TNF-α-stimulated intestinal epithelial NCM460 cells, rhapontin significantly increased the expressions of occludin and ZO-1 and notably reduced the ratio of bcl-2/bax and cleaved-capase9 expression through SRIT1 signaling. In sum, the protective effect of rhapontin is from blocking the NLRP3 priming cascade reaction and is dependent on SIRT1 activation. Our findings demonstrate that rhapontin might be a potential agent for the treatment of colitis by targeting SIRT1.     

Arctigenin inhibits lipopolysaccharide-induced iNOS expression in RAW264.7 cells through suppressing JAK-STAT signal pathway

Arctigenin has been demonstrated to have an anti-inflammatory function, but the precise mechanisms of its action remain to be fully defined. In the present study, we determined the effects of arctigenin on lipopolysaccharide (LPS)-induced production of proinflammatory mediators and the underlying mechanisms involved in RAW264.7 cells. Our results indicated that arctigenin exerted its anti-inflammatory effect by inhibiting ROS-dependent STAT signaling through its antioxidant activity. Arctigenin also significantly reduced the phosphorylation of STAT1 and STAT 3 as well as JAK2 in LPS-stimulated RAW264.7 cells. The inhibitions of STAT1 and STAT 3 by arctigenin prevented their translocation to the nucleus and consequently inhibited expression of iNOS, thereby suppressing the expression of inflammation-associated genes, such as IL-1β, IL-6 and MCP-1, whose promoters contain STAT-binding elements. However, COX-2 expression was slightly inhibited at higher drug concentrations (50 μM). Our data demonstrate that arctigenin inhibits iNOS expression via suppressing JAK-STAT signaling pathway in macrophages.     

Involvement of endoplasmic reticulum stress in angiotensin II-induced NLRP3 inflammasome activation in human renal proximal tubular cells in vitro

Aim:

NLRP3 inflammasome plays an important role in renal injury and may be a therapeutic target in the treatment of patients with progressive chronic kidney disease. In this study we investigated whether angiotensin II (Ang II)-induced NLRP3 inflammasome activation was linked to endoplasmic reticulum stress (ERS) in human renal proximal tubular cells in vitro.

Methods:

Human kidney proximal epithelial cells (HK-2) were pretreated with telmisartan or 4-PBA, and then treated with Ang II. The expression levels of mRNAs and proteins related to NLRP3 inflammasomes and ERS was examined by real-time PCR, Western blot and immunofluorescence.

Results:

Treatment with Ang II (10, 100, and 1000 nmol/L) increased the expression of the inflammasome markers NLRP3 and ASC, as well as caspase-1, IL-1β, and IL-18 in dose- and time-dependent manners with peak levels detected at 100 nmol/L and 12 h. Ang II-induced increases in the expression of NLRP3, ASC, caspase-1, IL-1β, and IL-18 were significantly reduced by pretreatment with telmisartan (1 μmol/L). Immunofluorescence studies showed that Ang II increased the expression of NLRP3 and ASC, which was inhibited by telmisartan. Furthermore, Ang II treatment increased the expression of ERS markers GRP78 and p-eIF2α in dose- and time-dependent manners, which was significantly reduced by telmisartan. Moreover, Ang II-induced increases in the expression of NLRP3, ASC, caspase-1, IL-1β, and IL-18 were significantly inhibited by pretreatment with the ERS inhibitor 4-PBA (5 mmol/L).

Conclusion:

Ang II treatment induces NLRP3 inflammasome activation in HK-2 cells in vitro and ER stress is involved in this process, which may represent a new mechanism for the renal rennin-angiotensin system to induce tubulointerstitial inflammation.     

Apolipoprotein E negatively regulates murine allergic airway inflammation via suppressing the activation of NLRP3 inflammasome and oxidative stress

Apolipoprotein E (ApoE) has been reported as a steroid unresponsive gene and functions as a negative regulator of airway hyperreactivity (AHR) and goblet cell hyperplasia in house dust mite (HDM)-challenged mice. However, the role of ApoE in Ovalbumin (OVA)-induced allergic airway inflammation disease and the underlying mechanism are still unknown. In the present study, murine allergic airway inflammation was induced by inhaled OVA for consecutive 7 days in wild type (WT) and ApoE^−/− mice. In the OVA-induced model, the ApoE level in the bronchoalveolar lavage fluid (BALF) and lung tissues was significantly higher than that of control mice. And ApoE deficiency aggravated airway inflammation including leukocytes infiltration, goblet cell hyperplasia and IgE production as compared to those of WT mice after OVA- challenged, suggesting ApoE servers as an endogenous negative regulator of airway inflammation. Furthermore, OVA challenge elevated the activation of NLRP3 inflammasome with higher protein expression of NLRP3, caspase1 and IL-1β, enhanced oxidative stress with higher expression of 8-OHdG, nitrotyrosine and SOD2, increased the expression of mitochondrial fusion/fission markers including Optic Atrophy 1 (OPA1), Mitofusion 2 (Mfn2), dynamin-related protein 1 (DRP1) and Fission 1 (Fis1). However, these OVA-induced changes were augmented in ApoE^−/− mice. Collectively, our results demonstrated that the OVA-induced airway inflammation was aggravated in ApoE^−/− mice, and suggested that the underlying mechanism may be associated with the augmented activation of NLRP3 inflammasome and oxidative stress in ApoE^−/− mice, therefore targeting ApoE pathway might be a novel therapy approach for allergic airway diseases such as asthma.     

Puerarin protects against myocardial ischemia/reperfusion injury by inhibiting inflammation and the NLRP3 inflammasome: The role of the SIRT1/NF-κB pathway

AimsThe purpose of this study was to investigate the protective effects of puerarin and elucidate the underlying mechanisms of puerarin in myocardial ischemia/reperfusion (MI/R) injury.Main methodsC57BL/6 mice were exposed to puerarin (100 mg/kg) with or without the SIRT1 inhibitor nicotinamide (500 mg/kg) and then subjected to MI/R operation. Myocardial infarct size, serum creatine kinase-MB (CK-MB) activity, apoptotic cell death, and cardiac structure and function were examined to evaluate MI/R injury. RT-PCR and western blotting were used to determine the inflammatory response and inflammasome activation, as well as activation of SIRT1/NF-κB pathway.ResultsPuerarin significantly reduced myocardial infarct size, serum CK-MB activity, and apoptotic cell death, and improved cardiac structural damage and dysfunction. Moreover, puerarin notably decreased the mRNA and protein levels of TNF-α, IL-6, and IL-1β, indicating that puerarin attenuated MI/R-induced inflammation. Furthermore, puerarin markedly decreased the protein levels of Ac-NF-κB, NLRP3, cleaved caspase-1, cleaved IL-1β, and cleaved IL-18 and increased the protein level of SIRT1. More importantly, the SIRT1 inhibitor nicotinamide prevented these puerarin-induced cardioprotective effects and regulation of the SIRT1/NF-κB pathway, as well as the NLRP3 inflammasome activation.ConclusionPuerarin protected against MI/R injury by inhibiting inflammatory responses probably via the SIRT1/NF-κB pathway, and inhibition of the NLRP3 inflammasome was also involved in puerarin-induced cardioprotective effects. These results suggest that puerarin may be a novel candidate for the treatment of ischemic heart disease.