Purinergic 2X7Receptor is Involved in the Podocyte Damage of Obesity-Related Glomerulopathy via Activating Nucleotide-Binding and Oligomerization Domain-Like Receptor Protein 3 Inflammasome

Background:The nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome composed of NLRP3,apoptosis-associated speck-like protein containing CARD (ASC),and caspase-1 is engaged in the inflammatory response of many kidney diseases and can be activated by purinergic 2X7 receptor (P2X7R).This study was conducted to explore whether P2X7R plays a pathogenic role in the podocyte damage of obesity-related glomerulopathy (ORG) and whether this role is mediated by the activation ofNLRP3 inflammasome.Methods:A mouse model of ORG was established by high-fat diet feeding.The conditionally immortalized mouse podocytes were cultured with leptin or with leptin and P2X7R antagonist (KN-62 or A438079).The mRNA and protein expression of the P2X7R and NLRP3 inflammasome components including NLRP3,ASC,and caspase-1,as well as the podocyte-associated molecules including nephrin,podocin,and desmin in mouse renal cortex or cultured mouse podocytes were tested by real-time-polymerase chain reaction and Westem blot analysis,respectively.Results:The significantly upregulated expression of P2X7R and NLRP3 inflammasome components and the NLRP3 inflammasome activation were observed in the renal cortex (in fact their location in podocytes was proved by confocal microscopy) of ORG mice in vivo,which were accompanied with the morphological changes of podocyte damage and the expression changes of podocyte-associated molecules.Similar changes in the expression of P2X7R and NLRP3 inflammasome components as well as in the expression ofpodocyte-associated molecules were also observed in the cultured podocyte studies treated by leptin in vitro,and all of the above changes were significantly attenuated by the P2X7R antagonist KN-62 or A438079.Conclusions:P2X7R could trigger the activation ofNLRP3 inflammasome,and the activated P2X7R/NLRP3 inflammasome in podocytes might be involved in the podocyte damage of ORG.

N-methyl-D-aspartic acid receptor 1 （NMDAR1） aggravates secondary inflammatory damage induced by hemin-NLRP3 pathway after intracerebral hemorrhage

Objective： Inflammation plays a critical role in secondary brain damage after intracerebral hemorrhage （ICH）. However, the mechanisms of inflammatory injury following ICH are still unclear, particularly the involvement of NLRP3 inflammasome, which are crucial to sterile inflammatory responses. In this study, we aim to test the hypothesis that NLRP3 signaling pathway takes a vital position in ICH-induced sec- ondary inflammatory damage and detect the role of N-methyl-D-aspartic acid receptor 1 （NMDARI） in this progress. Methods： ICH was induced in mice by microinjection of heroin into the striatum. The protein levels of NMDAR1, NMDAR1 phosphorylation, NLRP3 and IL-113 were measured by Western blot. The binding of NMDARI to NLRP3 was detected by immunoprecipitation. Results： The expression of NMDARI, NMDAR1 phosphorylation, NLRP3 and IL-I ~ were rapidly increased after ICH. Heroin treatment enhanced NMDAR1 expression and NMDAR1 phosphorylation, as well in cultured microglial cells treated by hemin. Hemin up-regulated NLRP3 and IL-I]3 level, which was reversed by MK801 （NMDAR antagonist） in vitro. Hemin also promoted the binding of NMDAR1 to NLRP3. Conclusion： Our findings suggest that NMDARI plays a pivotal role in hemin-induced NLRP3-mediated inflammatory damage through synergistic activation.

当归补血汤及其活性成分通过抑制NLRP3炎症小体活化改善糖尿病肾病的实验研究

目的:探究不同剂量的当归补血汤及其活性成分黄芪甲苷改善糖尿病肾病的作用机制及与NOD样受体蛋白3(nod-like receptor protein 3,NLRP3)炎症小体的相关性。方法:5 w~8 w的雄性GK大鼠分为模型对照组、阳性药格列喹酮10 mg/kg、盐酸贝那普利片10 mg/kg、当归补血汤2、4、8 g/kg组、黄芪甲苷40 mg/kg组,每组10只;10只雄性Wistar大鼠作为正常对照组。各组灌胃相应药物,正常对照组和模型对照组灌胃生理盐水,连续8 w。检测随机血糖、空腹血糖;计算肾脏系数;Elisa法检测大鼠尿液中白蛋白含量;HE染色观察肾脏组织病理改变;Western Blot法检测大鼠肾脏NLRP3、ASC、Caspase-1蛋白的表达。结果:与正常对照组相比,模型对照组大鼠的血糖、肾脏系数、尿白蛋白含量、炎症蛋白表达量均显著升高(P<0.01);与模型对照组比较,当归补血汤4、8 g/kg及其活性成分黄芪甲苷0.04 g/kg均可改善GK大鼠的体质量、血糖、肾脏肥大的情况,显著降低尿白蛋白含量,能有效抑制NLRP3小体的活化,其中8 g/kg组对调节血糖、降低尿白蛋白含量效果最为显著(P<0.01)。结论:不同剂量当归补血汤及其活性成分黄芪甲苷对GK大鼠肾脏均具有一定的保护作用,其机制与抑制NLRP3炎症小体密切相关。

PANoptosis-like cell death in ischemia/reperfusion injury of retinal neurons

PANoptosis is a newly identified type of regulated cell death that consists of pyroptosis,apoptosis,and nec roptosis,which simultaneously occur during the pathophysiological process of infectious and inflammatory diseases.Although our previous lite rature mining study suggested that PANoptosis might occur in neuronal ischemia/repe rfusion injury,little experimental research has been reported on the existence of PANoptosis.In this study,we used in vivo and in vitro retinal neuronal models of ischemia/repe rfusion injury to investigate whether PAN optosis-like cell death(simultaneous occurrence of pyroptosis,apo ptosis,and necroptosis)exists in retinal neuronal ischemia/repe rfusion injury.Our results showed that ischemia/repe rfusion injury induced changes in morphological features and protein levels that indicate PANoptosis-like cell death in retinal neurons both in vitro and in vivo.Ischemia/repe rfusion inju ry also significantly upregulated caspase-1,caspase-8,and NLRP3 expression,which are important components of the PANoptosome.These results indicate the existence of PANoptosis-like cell death in ischemia/reperfusion injury of retinal neurons and provide preliminary experimental evidence for future study of this new type of regulated cell death.

Maraviroc promotes recovery from traumatic brain injury in mice by suppression of neuroinflammation and activation of neurotoxic reactive astrocytes

Neuroinflammation and the NACHT,LRR,and PYD domains-containing protein 3 inflammasome play crucial roles in secondary tissue damage following an initial insult in patients with traumatic brain injury(TBI).Maraviroc,a C-C chemokine receptor type 5 antagonist,has been viewed as a new therapeutic strategy for many neuroinflammatory diseases.We studied the effect of maraviroc on TBI-induced neuroinflammation.A moderate-TBI mouse model was subjected to a controlled cortical impact device.Maraviroc or vehicle was injected intraperitoneally 1 hour after TBI and then once per day for 3 consecutive days.Western blot,immunohistochemistry,and TUNEL(terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling)analyses were performed to evaluate the molecular mechanisms of maraviroc at 3 days post-TBI.Our results suggest that maraviroc administration reduced NACHT,LRR,and PYD domains-containing protein 3 inflammasome activation,modulated microglial polarization from M1 to M2,decreased neutrophil and macrophage infiltration,and inhibited the release of inflammatory factors after TBI.Moreover,maraviroc treatment decreased the activation of neurotoxic reactive astrocytes,which,in turn,exacerbated neuronal cell death.Additionally,we confirmed the neuroprotective effect of maraviroc using the modified neurological severity score,rotarod test,Morris water maze test,and lesion volume measurements.In summary,our findings indicate that maraviroc might be a desirable pharmacotherapeutic strategy for TBI,and C-C chemokine receptor type 5 might be a promising pharmacotherapeutic target to improve recovery after TBI.

丁苯酞通过下调NF-κB信号通路抑制细胞焦亡减轻大鼠肾缺血-再灌注损伤

目的探讨丁苯酞对大鼠肾缺血-再灌注损伤(IRI)的作用机制。方法将40只SD大鼠随机分为假手术组(Sham组)、模型组(IRI组)、NF-κB抑制剂吡咯烷二硫代氨基甲酸酯(PDTC)组、丁苯酞低剂量组(NBP-L组)及丁苯酞高剂量组(NBP-H组),每组8只。检测各组大鼠血清肌酐(Scr)、血清胱抑素C(Cys-C)、血尿素氮(BUN)和血清白细胞介素(IL)-1β、IL-18水平,苏木素-伊红(HE)染色观察各组肾组织病理损伤情况,采用蛋白质印迹法和免疫组织化学法检测肾组织中炎症因子、核因子(NF)-κB信号通路及细胞焦亡相关蛋白表达水平。结果与Sham组比较,IRI组肾组织损伤较为严重,Scr、Cys-C、BUN和血清IL-1β、IL-18水平均升高,蛋白质印迹法结果显示NOD样受体蛋白(NLRP3)、Gasdermin D(GSDMD)、半胱氨酸天冬氨酸蛋白酶(Caspase)-1、IL-18、IL-1β、NF-κB p65、p-NF-κB p65蛋白相对表达量均增加,免疫组织化学染色结果显示NF-κB p65、p-NF-κB p65、IL-1β、IL-18和NLRP3蛋白表达均增多。与IRI组比较,PDTC组、NBP-L组和NBP-H组肾组织的损伤程度均减轻,Scr、Cys-C、BUN和血清IL-18、IL-1β水平均下降,蛋白质印迹法结果显示NLRP3、GSDMD、Caspase-1、IL-1β、IL-18、NF-κB p65、p-NF-κB p65蛋白表达均减少,免疫组织化学染色结果显示NF-κB p65、p-NF-κB p65、IL-1β、IL-18和NLRP3蛋白表达均下降。与NBP-L组比较,NBP-H组肾组织的损伤程度减轻,Scr、Cys-C、BUN和血清IL-18、IL-1β水平均下降,蛋白质印迹法结果显示NLRP3、GSDMD、Caspase-1、IL-1β、IL-18、NF-κB p65、p-NF-κB p65蛋白表达均减少,免疫组织化学染色结果显示NF-κB p65、p-NF-κB p65、IL-1β、IL-18和NLRP3蛋白表达均下降。结论丁苯酞可下调NF-κB/NLRP3信号通路的活性,降低肾IRI后焦亡相关蛋白的表达水平及炎症因子水平,进而抑制细胞焦亡,减轻肾IRI。

针灸改善DDP化疗致肾脏损伤模型小鼠的作用机制

目的从肾脏炎症反应角度探讨针灸改善顺铂(DDP)化疗致小鼠肾脏损伤的机制和保护作用。方法40只SPF级雄性KM小鼠,随机分为4组,每组10只。空白组采用0.9%NaCl溶液腹腔注射,余下3组注射同等剂量10 mg/kg的DDP溶液,24 h后模型复制成功。针刺组选用0.18 mm×13 mm毫针直刺3 mm,留针6 min。艾灸组选用0.4 cm×12 cm细艾条垂直穴位上2 cm悬灸6 min,穴位均选用“大椎”“肝俞”(双穴)“肾俞”(双穴)“足三里”(双穴),其余两组仅陪同固定,1次/d,连续5 d。禁食1 d后取材,酶联免疫吸附试验(ELISA)检测各组血清尿素氮(BUN)和血肌酐(Scr)含量,免疫荧光法观察髓样分化因子(MyD)88、IκB激酶(IKK)α、NOD样受体蛋白(NLRP)3表达,Western印迹和RT-聚合酶链反应(PCR)法检测MyD88、IKKα、NLRP3蛋白和mRNA表达。结果与空白组比较,模型组血清BUN、Scr含量明显升高,肾组织中MyD88、IKKα、NLRP3蛋白和mRNA表达明显升高(P<0.05),荧光表达均增强。与模型组比较,针刺组和艾灸组血清BUN、Scr含量明显降低,肾组织中MyD88、IKKα、NLRP3蛋白和mRNA表达明显降低(P<0.05),荧光表达均减弱。结论针灸可能通过下调MyD88、IKKα及NLRP3表达水平,减轻模型小鼠肾脏损伤,改善肾功能,对化疗所致肾脏损伤有明显的增效保护作用。