AKT/FOXO1信号通路在心力衰竭小鼠骨骼肌萎缩中的作用

目的:探讨AKT/FOXO1信号通路在心力衰竭(HF)小鼠骨骼肌萎缩中的作用。方法:采用主动脉弓横向结扎8周,复制小鼠HF动物模型。采用实时定量-聚合酶链式反应和Western blot技术检测HF小鼠胫骨前肌内,E3连接酶的2个肌肉萎缩特异性指标Atrogin-1和MuRF1,对胫骨前肌中转录因子FOXO1和激酶AKT的磷酸化水平和总蛋白水平进行测定,并比较磷酸化蛋白和总蛋白的比率。结果:与对照组小鼠相比,TAC 8周诱导HF小鼠的胫骨前肌肌纤维变小,质量减轻。RT-PCR分析结果显示,HF小鼠胫骨前肌内的Atrogin-1和MuRF1的mRNA表达明显上调(P0.01)。Western blot分析结果显示,HF小鼠胫骨前肌组织中Atrogin-1和MuRF1的蛋白相对表达量HF组较对照组明显增加(P0.01)。HF组小鼠胫骨前肌中p-FOXO1的表达水平较对照组增加,FOXO1的总蛋白水平显著下降;p-AKT的蛋白表达较对照组增加(P0.05),AKT的总蛋白水平差异无统计学意义。p-FOXO1/FOXO1和p-AKT/AKT比率HF组明显高于对照组(P0.01)。结论:AKT/FOXOs信号通路参与HF后骨骼肌萎缩的过程并发挥重要作用。     

过氧化物酶增殖体激活受体γ辅助激活子-1α在脓毒症肺损伤大鼠肺组织中的表达

目的探讨脓毒症肺损伤大鼠过氧化物酶增殖体激活受体γ辅助激活子-1α(PGC-1α)在急性肺损伤(ALI)发病中的作用。方法将54只SD大鼠随机分为9组:正常对照组(6只);假手术组3、6、12、24 h(各6只);盲肠结扎穿孔组3、6、12、24 h(各6只)。利用盲肠结扎穿孔手术复制大鼠急性肺损伤模型。HE染色观察大鼠肺组织病理情况;ELISA检测血浆炎症因子(IL-1β、TNFα、IL-6)表达变化;real-time PCR检测肺组织PGC-1αmRNA表达;Western blot检测肺组织PGC-1α蛋白表达情况。结果大鼠经盲肠结扎穿孔后,肺组织显示出血、肺泡塌陷、肺泡间隔增厚、肺间质水肿及大量炎症细胞浸润等肺部炎症的表现。与正常对照组比较,假手术组各时间点大鼠血浆炎症因子(IL-1β、TNFα、IL-6)、肺组织PGC-1αmRNA及蛋白表达水平均无统计学差异(P>0.05);盲肠结扎穿孔组各时间点血浆炎症因子(IL-1β、TNFα、IL-6)表达水平较正常对照组明显升高(P<0.05),且成时间效应关系;肺组织PGC-1αmRNA及蛋白表达水平较正常对照组明显降低(P<0.05),并随着术后时间的延长逐渐降低(P<0.05)。结论正常大鼠肺组织可表达PGC-1α,脓毒症肺损伤大鼠肺组织内PGC-1α的mRNA和蛋白表达水平下降,提示PGC-1α可能参与ALI的发生发展过程。     

硫化氢对血管性痴呆大鼠缺血再灌注损伤中NLRP3表达的影响

目的探讨硫化氢(H₃S)对血管性痴呆(VaD)大鼠缺血再灌注损伤(IRI)中NLRP3表达的影响。方法采用改良四血管法(4-VO)制作VaD大鼠IRI模型,随机数字表法将大鼠分为假手术组、模型组、抑制剂组(CY-09组)、NaHS组,每组各6只,共24只大鼠。应用Morris水迷宫实验评价大鼠学习记忆能力,收集各组大鼠脑组织标本,采用苏木素-伊红(HE)染色,观察海马区形态。各组大鼠血清H₃S含量采用亚甲蓝法检测;白细胞介素(IL)-1β、IL-18采用酶联免疫吸附试验(ELISA)检测;用Western印迹检测各组大鼠海马组织中炎症小体NLRP3、Caspase-1表达水平。结果VaD大鼠模型构建成功;模型组大鼠海马区神经元细胞损伤明显,海马组织NLRP3、Caspase-1蛋白相对表达量显著增加(P<0.05)。NaHS组大鼠海马区神经元细胞损伤减轻,血清H₃S含量较模型组明显升高(P<0.05),海马组织NLRP3、Caspase-1蛋白较模型组降低(P<0.05);CY-09组大鼠海马区神经元细胞损伤减轻,海马组织NLRP3、Caspase-1蛋白较模型组降低(P<0.05),血清IL-1β、IL-18显著低于模型组(P<0.05)。结论VaD大鼠IRI可引起NLRP3表达增加;H₃S能够通过降低NLRP3表达,减轻大鼠IRI。     

Foxo1及泛素溶酶体系统在慢性肾脏病致骨骼肌萎缩作用中的初步观察

 目的 观察终末期肾病患者骨骼肌萎缩表现,并初步探讨腹直肌中转录因子Foxo1及泛素溶酶体系统活性变化与骨骼肌萎缩的关系。方法 对慢性肾脏病(CKD)5期的22例尿毒症患者在腹膜透析置管术中行腹直肌活检。并将8例诊断为子宫腺肌病并拟行经腹全子宫切除术患者及6例确诊为腹壁疝并拟行腹壁疝修补术患者设为对照组,于手术时留取少许腹直肌标本。观察肌纤维形态、计算肌纤维横截面积,并检测Foxo1及泛素溶酶体系统标志物Atrogin-1及MuRF1的mRNA和蛋白的表达情况。结果 CKD组患者腹直肌肌纤维的横截面面积较对照组明显缩小(P<0.01),CKD组Foxo1、Atrogin-1及MuRF1的mRNA含量及蛋白表达量均较对照组明显增加(P<0.05),而p-Foxo1蛋白表达量较对照组降低(P<0.05)。结论 CKD患者存在肌萎缩现象,推测其与Foxo1表达上调、磷酸化程度降低以及泛素溶酶体系统活性亢进有关。     

结肠灵通过调节NLRP3炎性小体活化对感染后肠易激综合征大鼠内脏敏感性的机制研究

目的探讨核苷酸结合寡聚化结构域样受体3(NLRP3)炎症小体在结肠灵调节感染后肠易激综合征(PI-IBS)内脏高敏感性中的作用及分子机制。方法选取SPF级雄性SD大鼠40只随机分配到4组:正常对照组、模型组、结肠灵组和阳性对照组。HE染色检测大鼠结肠组织中性粒细胞等炎症细胞浸润情况及黏膜损伤状况;利用腹壁回缩反射(AWR)评分和粪便含水量评估大鼠的内脏敏感性。ELISA检测大鼠血清中IL-18和IL-1β表达;Western blotting检测NLRP3、ASC、Caspase-1、IL-18、IL-1β及NF-κB表达。结果正常对照组大鼠结肠黏膜完整,无炎症细胞浸润;模型组大鼠结肠黏膜受损,有大量炎症细胞(中性粒细胞等)浸润,AWR评分值显著升高(P0.01),粪便含水量也显著增加(P0.01);给予药物干预后黏膜组织完整性恢复,降低了炎症细胞浸润,AWR评分值和大鼠粪便含水量显著降低(P0.05)。结肠灵干预降低了大鼠血清中IL-18和IL-1β含量(P0.05),显著抑制NLRP3、ASC、Caspase-1、IL-18、IL-1β及NF-κB蛋白表达(P0.05)。结论结肠灵可能通过NF-κB通路抑制NLRP3炎症小体活化,降低大鼠结肠黏膜炎症,改善PI-IBS大鼠内脏敏感性。     

白果内酯通过NLRP3相关通路发挥对乙醇致大鼠胃溃疡的保护作用

背景白果内酯对胃溃疡胃黏膜损伤有一定的保护作用,但其具体的作用机制尚不清楚.目的探讨白果内脂通过NOD样受体热蛋白结构域相关蛋白3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)通路改善乙醇诱导胃溃疡的分子机制.方法将60只SD大鼠随机分为空白组(A组,不做处理),模型组(B组,乙醇诱导的急性胃溃疡模型),对照组(C组,20 mg/mL奥美拉唑),低剂量组(D组,1 mg/mL白果内酯)、中剂量组(E组,2.5 mg/mL白果内酯)和高剂量组(F组,5 mg/mL白果内酯),每组10只,比较不同组别大鼠的胃液pH值、胃泌素、胃蛋白酶以及溃疡指数(ulcer index,UI)等,采用Elisa方法检测大鼠腹主动脉血清以及眼眶血清中的NLRP3、半胱氨酸蛋白酶-1(Caspase-1)、IL-18和IL-1β、超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)和还原型谷胱甘肽(reduced glutathione,GSH)含量.采用实时荧光定量PCR、免疫印迹(WB)法以及免疫荧光法检测胃组织中NLRP3相关通路中NLRP3、白介素-18(IL-1β)、IL-1β、Caspase-1和调亡相关斑点样蛋白(apoptosis associated blotch-like protein,ASC)的表达量变化.结果B组UI、胃泌素、总酸度和胃蛋白酶总活性均明显高于A组(P<0.01),C组,E组和F组的UI、总酸度和胃蛋白酶总活性均低于B组(P<0.01).C组,D组,E组和F组大鼠血清中SOD值和GSH值较B组明显升高(P<0.01).B组大鼠MDA值、NLRP3、Caspase-1、IL-18、IL-1β、Caspase-1和ASC蛋白的mRNA水平和蛋白表达量均明显高于A组(P<0.01).C组,D组,E组和F组大鼠胃组织中MDA值、NLRP3、Caspase-1、IL-18、IL-1β、Caspase-1和ASC蛋白的mRNA水平和蛋白表达量均低于B组(P<0.01).结论白果内脂可通过NLRP3通路抗炎机制达到胃溃疡的保护作用.     

双氢青蒿素对AngⅡ诱导的心肌成纤维细胞及NLRP3炎性小体活性的影响

目的:探讨双氢青蒿素(DHA)对血管紧张素Ⅱ(AngⅡ)诱导的心肌成纤维细胞增殖、转分化及激活NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎性小体的作用,分析DHA拮抗心肌纤维化的分子机制。方法:采用胰酶消化新生大鼠的心肌组织,分离出成纤维细胞并进行免疫鉴定。实验分为正常组、DHA对照组、AngⅡ组、DHA处理组。比较各组细胞的数量变化;采用酶联免疫吸附试验检测各组细胞孵育液中Ⅰ型胶原和Ⅲ型胶原含量;蛋白免疫印迹法(Western Blot)检测各组细胞表型分子α-平滑肌肌动蛋白(α-SMA)的表达,细胞内NLRP3、半胱氨酸蛋白酶-1(Caspase-1)和白细胞介素-1β(IL-1β)的含量。结果:与正常组比较,DHA对照组吸光度值、Ⅰ型胶原和Ⅲ型胶原含量、细胞表型分子α-SMA表达、细胞内NLRP3、Caspase-1和IL-1β表达水平,差异均无统计学意义(P>0.05),AngⅡ组吸光度值增加,孵育液中Ⅰ型胶原和Ⅲ型胶原含量、细胞表型分子α-SMA表达升高,细胞内NLRP3、Caspase-1和IL-1β表达增加,差异均有统计学意义(P<0.05或P<0...     

白介素15与慢性阻塞性肺疾病大鼠骨骼肌降解的相关性研究

目的 研究慢性阻塞性肺疾病(COPD)大鼠模型骨骼肌降解途径——泛素-蛋白酶体途径与白介素15(IL-15)的相关关系,为有效防治COPD患者骨骼肌蛋白高分解提供理论与依据.方法 成年雄性SD大鼠45只,分为模型组30只,健康组15只,采用反复熏香烟加气管内注入脂多糖法复制COPD大鼠动物模型.实时荧光定量PCR法和Western blot法分别检测大鼠膈肌、腓肠肌和肋间肌中E2-14K、MAFbx、Ub基因和蛋白表达.ELISA法检测大鼠血清、膈肌、腓肠和肋间肌中IL-15和肿瘤坏死因子α(TNF-α)的含量.结果 COPD模型大鼠膈肌、腓肠肌和肋间肌中E2 14K、MAFbx、Ub基因和蛋白表达分别较健康组升高.COPD模型组大鼠血清、膈肌、腓肠肌和肋间肌中IL-15、TNF-α的水平较健康组升高.大鼠血清、膈肌、腓肠肌和肋间肌中IL-15和TNF-α水平呈正相关(血清r=0.75;膈肌r =0.81;腓肠肌r=0.82;肋间肌r=0.78,P值均＜0.05).膈肌、腓肠肌和肋间肌中IL-15均与E2-14K、MAFbx、Ub相对表达量呈正相关(膈肌r=0.88、r=0.86、r=0.87;腓肠肌r=0.85、r=0.87、r=0.76;肋间肌r=0.85、r =0.80、r=0.84,P值均＜0.05).大鼠造模结束后体质量净增长与血清、膈肌、腓肠肌和肋间肌中IL-15呈负相关(血清r=-0.90,膈肌r=-0.85,腓肠肌r=-0.82,肋间肌r=-0.82,P＜0.05).结论 在COPD模型大鼠中,IL-15可能通过TNF-α共同作用于泛素-蛋白酶体途径影响骨骼肌降解的作用.     

NLRP3炎症小体在高脂诱导大鼠冠状动脉硬化性心脏病形成中的表达水平及意义

目的探讨NLRP3炎症小体在冠状动脉硬化性心脏病(冠心病,CAD)大鼠心肌组织和冠状动脉(冠脉)组织中的表达水平,并初步探索NLRP3炎症小体致大鼠冠心病形成中的作用。方法通过高脂饮食诱导制备大鼠冠心病动物模型,分析各组实验动物血液中总胆固醇(TC),三酰甘油(TG)水平;通过RT-qPCR及Western Blot等方法对NLRP3炎症小体及其作用蛋白白介素1β(IL-1β)心肌组织中的m RNA及蛋白表达水平进行测定;通过心脏超声检查、心肌及冠状动脉组织病理切片评价NLRP3炎症小体对CAD形成的影响。结果血清学检测发现高脂饮食大鼠与正常饮食大鼠相比较TC与TG水平明显增高(P0.05);通过RT-qPCR及Western Blot检测NLRP3炎症小体及作用蛋白IL-1β在高脂饮食组大鼠心肌组织中表达水平明显上调(P0.05);通过大鼠冠状动脉、心肌组织病理切片及心脏超声发现,高脂饮食组大鼠冠状动脉出现明显粥样斑块并伴管腔内径缩小,心脏增大明显且心功能下降明显(P0.05);心脏结构和功能改变与NLRP3炎症小体及作用蛋白IL-1β表达上调有关。结论 NLRP3炎症小体参与了CAD的发生发展过程。     

NLRP3炎症小体在海水吸入性急性肺损伤中的表达和作用

目的探讨海水吸入型急性肺损伤大鼠肺组织中NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎症小体表达的变化及介导的炎性因子在急性肺损伤(ALI)发生发展中的作用。 方法将50只健康雄性SD大鼠随机分为5组,对照组,海水吸入1 h组,海水吸入3 h组,海水吸入6 h组,海水吸入9 h组,每组10只。采用经气管缓慢滴注(3 ml/kg)海水的方法制作大鼠损伤模型。制作大鼠肺脏石蜡切片并HE染色观察病理形态学变化。检测大鼠肺组织湿干比。ELISA检测测定各组肺组织中IL-1β和IL-18水平,RT-PCR检测肺组织中IL-1β、IL-18和NLRP3mRNA的表达。Western-blot检测肺组织中NLRP3蛋白表达。 结果气管滴注海水后成功复制海水吸入性急性肺损伤模型。肺组织湿干比较对照组显著升高。病理形态学观察可见肺组织大量炎细胞浸润、水肿、间质增厚。各组大鼠血清中IL-1β和IL-18的水平随着时间增加逐渐升高,且在3～6 h达到顶峰,随后炎症因子的表达逐渐降低。与空白对照组比较,差异均有统计学意义(均P<0.05)。各组大鼠肺组织中IL-1β和IL-18的mRNA的表达水平与大鼠肺组织中IL-1β和IL-18的表达基本一致。与空白对照组比较,差异均有统计学意义(均P<0.05)。肺组织匀浆中NLRP3转录和翻译结果显示海水吸入刺激后,肺组织中NLRP3的mRNA和NLRP3蛋白含量变化含量随着时间明显逐渐增加,差异均有统计学意义(均P<0.05)。 结论海水刺激下,NLRP3炎症小体介导的炎症反应参与了急性肺损伤发病过程并加重了肺损伤的程度,可能是海水急性肺损伤的发病机制之一,但其作用有待进一步证实。     

Suppression of atrogin-1 and MuRF1 prevents dexamethasone-induced atrophy of cultured myotubes

Objective

The mechanistic role of the ubiquitin ligases atrogin-1 and MuRF1 in glucocorticoid-induced muscle wasting is not fully understood. Here, we tested the hypothesis that glucocorticoid-induced muscle atrophy is at least in part linked to atrogin-1 and MuRF1 expression and that the ubiquitin ligases are regulated by compensatory mechanisms.

Methods

The expression of atrogin-1 and MuRF1 was suppressed individually or in combination in cultured L6 myotubes by using siRNA technique. Myotubes were treated with dexamethasone followed by determination of mRNA and protein levels for atrogin-1 and MuRF1, protein synthesis and degradation rates, and myotube morphology.

Results

Suppression of atrogin-1 resulted in increased expression of MuRF1 and vice versa, suggesting that the ubiquitin ligases are regulated by compensatory mechanisms. Simultaneous suppression of atrogin-1 and MuRF1 resulted in myotube hypertrophy, mainly reflecting stimulated protein synthesis, and prevented dexamethasone-induced myotube atrophy, mainly reflecting inhibited protein degradation.

Conclusions

The results provide evidence for a link between upregulated atrogin-1 and MuRF1 expression and glucocorticoid-induced muscle atrophy. The study also suggests that atrogin-1 and MuRF1 levels are regulated by compensatory mechanisms and that inhibition of both ubiquitin ligases may be needed to prevent glucocorticoid-induced muscle proteolysis and atrophy.     

Short-term growth hormone or IGF-I administration improves the IGF-IGFBP system in arthritic rats

ObjectiveAdjuvant-induced arthritis is an experimental model of rheumatoid arthritis that inhibits the GH-IGF-I axis and decreases body weight gain and muscle mass. Although chronic GH or IGF-I treatment increases body weight gain in arthritic rats, muscle resistance to GH and IGF-I is a very common complication in inflammatory diseases. In this study we examine the effect of short-term administration of rhGH and rhIGF-I on liver and muscle IGF-I, IGFBP-3 and ? 5 as well as on the ubiquitin-ligases MuRF1 and atrogin-1 in the muscle of arthritic rats.DesignArthritis was induced in adult male Wistar rats by an intradermal injection of 4 mg of Freund's adjuvant. Fifteen days after adjuvant injection, 300 μg/kg of rhGH or 200 μg/kg of rhIGF or saline was administrated 18 and 3 h before decapitation. A pair-fed group injected with saline was included in order to discard a possible effect of decreased food intake. Gene expression of IGF-I, GHR, IGFBP-3, IGFBP-5, atrogin-1 and MuRF1 were quantified using RT-PCR. In serum, IGF-I was measured by radioimmunoassay (RIA) and IGFBP-3 by ligand blot.ResultsArthritis decreased serum IGF-I and IGF mRNA in liver (P < 0.05), but not in skeletal muscle. In arthritic rats, rhGH increased serum IGF-I and liver IGF-I mRNA similar to the levels of pair-fed rats. Arthritis increased atrogin-1, MuRF1, IGFBP-3 and IGFBP-5 mRNA in muscle (P < 0.01). IGFBP-3 mRNA was downregulated by rhIGF-I, but not by rhGH, administration in control and arthritic rats (P < 0.05). Administration of rhGH and rhIGF-I increased IGFBP-5 in the gastrocnemius of arthritic rats.ConclusionsShort-term rhGH and rhIGF-I administration was found to increase muscle IGFBP-5 mRNA, whereas only rhIGF-I administration decreased muscle IGFBP-3 mRNA in control and arthritic rats. These data suggest that arthritis does not induce GH or IGF-I resistance in skeletal muscle.     

不同频率神经肌肉电刺激对ARDS相关性ICU-AW小鼠肌肉萎缩防治及临床意义

目的 不同频率下神经肌肉电刺激(neuromuscular electrical stimulation,NMES)在ARDS相关性ICU获得性衰弱(ICU-acquired weakness,ICU-AW)中的作用及机制。方法 健康雄性C57BL/6小鼠88只随机分为11组,每组8只。分为:空白对照组(C1)、气管内注入无菌水组(C2)、ICU-AW模型组(ICU-AW)、ICU-AW+AMPK激动剂A-769662组(ICU-AW-A)、ICU-AW+A-769662溶剂对照组(ICU-AWV)、NMES 20 Hz组(ICU-AW-20)、NMES 40 Hz组(ICU-AW-40)、NMES 60 Hz组(ICU-AW-60)、NMES80 Hz组(ICU-AW-80)、ICU-AW-40+AMPK抑制剂Compound C组(ICU-AW-40-C)、ICU-AW-40+Compound C溶剂对照组(ICU-AW-40-V)。检测小鼠四肢抓力和存活状态,7 d后收集小鼠肺组织和腓肠肌标本,采用HE染色观察肺和肌肉病理学变化,采用western blot以及qRT-PCR的方...     

Plasma levels of 6-keto PGF1 alpha but not TxB2 increase in rats with peritonitis due to cecal ligation

Acute, overwhelming sepsis or endotoxemia in experimental animals is associated with increased circulating levels of thromboxane (Tx)B2 (stable metabolite of TxA2) and 6-keto PGF1 alpha (stable metabolite of prostacyclin). The purpose of the present investigation was to determine the plasma prostanoid response to sepsis using an animal paradigm in which the septic process evolved more slowly than in previous similar studies. Bacterial peritonitis was induced in rats by cecal ligation (group B) or cecal ligation plus puncture with a 22-gauge needle (group C). Compared to sham-operated controls (group A), levels of immunoreactive 6-keto PGF1 alpha were significantly (p less than .05) elevated in group C rats at 6, 12, and 24 hr after surgery. At 48 hr after surgery, levels of this prostanoid were significantly (p less than .05) elevated in group B animals. In contrast, TxB2 levels were never significantly increased in septic (groups B and C) as compared to control (group A) rats. These data are consistent with results from several clinical studies and emphasize an important difference between the cecal ligation model and other experimental sepsis paradigms.     

NLRP3炎症小体在大鼠严重烫伤早期心肌内的表达及意义

目的 探讨严重烫伤大鼠早期心肌组织内NLRP3炎症小体信号通路的表达及意义。方法 采用大鼠95℃热水浴18 s,制成40%总体表面积Ⅲ度烫伤模型,将24只健康雄性SD大鼠按随机数表法分为对照组、烫伤组、干预组。烫伤组大鼠立即腹腔注射10 ml生理盐水补液;干预组大鼠注射10 ml生理盐水+(BAY11-7082) 10 μl(0.2 mg/ml,10 mg/kg);对照组动物背部置于25℃温水浴18 s模拟烫伤过程。伤后8 h分别取各组大鼠心肌组织及血清,采用蛋白免疫印迹法和实时荧光定量RT-PCR法检测心肌组织中NLRP3、半胱氨酸天冬氨酸蛋白酶（caspase）-1蛋白表达水平和NLRP3、caspase-1、IL-1β、TNF-α mRNA表达水平,同时观察HE染色组织大体形态,酶联免疫吸附试验法检测血清肌酸激酶同工酶（CK-MB）、乳酸脱氢酶（LDH）含量。结果 ①烫伤组大鼠心肌组织内NLRP3、caspase-1蛋白表达量显著高于对照组（P<0.01）;与烫伤组比较,干预组大鼠心肌组织内NLRP3、caspase-1明显降低（P<0.01）;②烫伤组大鼠心肌组织中NLRP3、caspase-1、IL-1β和TNF-α的mRNA表达量分别为3.15±0.46,2.47±0.24,3.26±0.22和2.17±0.32,显著高于对照组的1.00±0.09,1.00±0.06,1.00±0.08和1.00±0.07（均P<0.01）;干预组大鼠心肌组织中NLRP3、caspase-1、IL-1β和TNF-α的mRNA表达量分别为1.68±0.37,1.55±0.17,1.21±0.15和1.38±0.23,显著低于烫伤组（均P<0.01）;③对照组大鼠心肌组织呈不规则圆柱形、排列整齐、横纹清晰,结构完整。烫伤组大鼠部分心肌纤维排列紊乱,细胞和间质可见水肿,见点片状溶解灶及炎性细胞浸润。BAY11-7082干预组部分心肌纤维排列紊乱,心肌细胞和间质水肿、心肌纤维溶解及炎细胞浸润程度均较烫伤组减轻;④烫伤组大鼠血清CK-MB、LDH含量分别为(2753±825)U/L,(2618±238)U/L,显著高于对照组的(247±76)U/L,(721±59)U/L（均P<0.01）;干预组大鼠血清CK-MB、LDH含量分别为(1267±248)U/L,(1982±183)U/L,显著低于单纯烫伤组（均P<0.01）。结论 NLRP3炎症小体在严重烫伤大鼠早期心肌组织内活性增高,使用BAY11-7082干预后,可抑制NLRP3炎症小体的活化,减轻心肌组织损伤,降低心肌炎症反应。     

Role of NLRP3 and NLRP1 inflammasomes signaling pathways in pathogenesis of rheumatoid arthritis

Objective:To investigate the role of NLRP3 and NLRP1 inflammasomes signaling pathways in rheumatoid arthritis(RA).Methods:A total of 36 patients with RA were selected,peripheral blood mononuclear cell(PBMC)and granulocyte were separated from venous blood.RT-qPCR method was used to detect the expression level and diversity of NLRP3 and NLRP1 in PBMC and granulocyte mRNA in patieuts with RA.and detect the mRNA expression of downstream factor IL-1β.The correlation between RA and the expression of NLRP3 aud NLRP1 was analyzed.Normal 30 cases were set as control group.Results:Expression levels of NLRP1.and caspase-1mRNA in PBMC of RA group were significautly lower than those of control group(P0.05).while there was no significant differeuee in expression levels of NLRP3,ASC.IL-1βmRNA between these two groups(P0.05);NLRP3,caspase-1,and ASC mRNA expression in granulocyte of RA patients were significantly lower than those in control group(P0.05).There was no currelation between rheumatoid factor and expression levels of NLRP3.ASC.caspase-1 mRNA in RA group(P0.05);NLRP1,IL-1βmRNA expression level had a negative corrlation with anti-rheunatoid factor antibody(P=0.0332,0.0340).Conclusions:NLRP3 and NLRP1 inflammasomes signaling pathways are involved in RA inflammatory reaction process as protective factors,and play an important role in RA inflammatory mechanisms.     

Upregulated NLRP3 inflammasome activation is attenuated by anthocyanins in patients with nonalcoholic fatty liver disease: A case-control and an intervention study

ObjectivesDespite the recent attention focused on the roles of the NLRP3 inflammasome in the pathogenesis of metabolic and inflammatory diseases, little is known about the activation status of NLRP3 inflammasome in patients with nonalcoholic fatty liver disease (NAFLD). The present study aimed to investigate whether inflammasomes activation is upregulated in patients with NAFLD and the upregulation can be attenuated by anthocyanins, which are polyphenols with known anti-inflammatory activities.MethodsThis study included a case-control study and a randomized controlled intervention trial. In the first part, NAFLD patients and healthy controls were recruited from a cohort of railroad workers. In the second part, NAFLD patients were randomly assigned to receive either capsules of anthocyanins (320 mg daily) or placebo for 12 weeks. A series of genes and factors associated with activation of NLRP3 inflammasome in subjects’ plasma and peripheral blood mononuclear cells (PBMCs) were analyzed.ResultsCompared with healthy controls, the mRNA levels of NLRP3 inflammasome components (NLRP3, caspase-1, interleukin (IL)-1β, and IL-18) were significantly upregulated in the PBMCs of NAFLD patients. Consistently, plasma levels of mature IL-1β and IL-18 in NAFLD patients were significantly higher than in controls. After anthocyanin administration, both mRNA expression of NLRP3 inflammasome components (caspase-1, IL-1β, and IL-18) in PBMCs and plasma levels of IL-1β and IL-18 decreased dramatically in NAFLD patients compared with controls.ConclusionsThis study has demonstrated that the activation of NLRP3 inflammasome is highly increased in NAFLD patients, but it can be markedly suppressed by anthocyanins, which provides a rationale for the development of anti-inflammatory therapies in NAFLD.     

MG132-mediated inhibition of the ubiquitin–proteasome pathway ameliorates cancer cachexia

Purpose

To evaluate the effect of proteasome inhibitor MG132 in cancer cachexia and to delineate the molecular mechanism underlying.

Methods

We established an experimental cancer cachexia model by subcutaneously implanting colon 26 cells into the armpits of BALB/c mice. Following administration of MG132 at various time points, body weight, food intake, gastrocnemius muscle weight, spontaneous activity and survival of tumor-bearing mice were examined along with tumor growth. Moreover, cachectic markers including glucose, triglyceride, albumin and total proteins as well as levels of the proinflammatory cytokines TNF-α and IL-6 in serum and gastrocnemius tissue were measured. Finally, mRNA and protein levels of p65, IκBα, and ubiquitin E3 ligases MuRF1 and MAFbx in gastrocnemius muscle were assessed.

Results

MG132 treatment significantly alleviated cancer cachexia as demonstrated by attenuated weight loss, altered carbohydrate metabolism and muscle atrophy and increased spontaneous activity and survival time of tumor-bearing mice. MG132 reduced tumor growth and the levels of TNF-α and IL-6 in serum and gastrocnemius tissue. NF-κB, MuRF1 and MAFbx were also inhibited by MG132. Unexpectedly, MG132 was more efficient when administrated during the early stages of cachexia. MG132 had no effect on food intake of tumor-bearing mice.

Conclusion

Our results demonstrate that MG132-induced inhibition of the ubiquitin–proteasome pathway in cancer cachexia decreased the activity of NF-κB and the degradation of IκBα, and reduced the levels of TNF-α and IL-6 in serum and gastrocnemius tissue, accompanied by downregulation of MuRF1 and MAFbx. These data suggest that MG132 is a potential therapeutic and preventive agent for cancer cachexia.