IFI27L2慢病毒稳定干涉细胞系的建立以及其在炎症小体激活中的功能鉴定

通过构建IFI27L2分子的慢病毒干涉表达载体,建立IFI27L2表达下调的THP1、U937稳定细胞系。将携带特异性干涉IFI27L2的DNA片段克隆插入p LKO.1载体中,并制备携带不同干涉序列的慢病毒颗粒。将获得的慢病毒颗粒感染THP1、U937细胞,建立稳定干涉细胞系,经Real-time PCR和Western blot法分别从mRNA和蛋白质水平检测THP1、U937细胞中内源IFI27L2的干涉效果。构建的重组质粒经酶切鉴定shRNA正确插入慢病毒载体,测序鉴定序列正确;并有干涉效果。成功制备了稳定干涉IFI27L2的慢病毒颗粒,建立IFI27L2稳定下调的THP1、U937两种细胞系;并初步证明稳定干涉IFI27L2能够抑制NLRP3炎症小体的激活。     

NLRP3炎症小体在肾脏疾病中的作用机制与干预策略

NOD样受体家族核苷酸结合寡聚化结构域样受体3(NLRP3)炎症小体是胞质中的一种多蛋白复合体,由NLRP3、凋亡相关的斑点样蛋白(ASC)及半胱氨酸天冬氨酸蛋白酶-1(Caspase-1)组成,可识别病原微生物感染或细胞损伤信号,启动固有免疫应答,促进炎症反应.随着对炎症小体的深入研究发现,NLRP3炎症小体活化失调与肾脏疾病密切相关.有研究显示,以BAY11-7082、MCC950为代表的小分子化合物抑制剂可通过减轻炎性反应而改善肾脏损伤.此外,一些口服中药、中药复方及中药提取物在一定程度上也能经过多种途径干预NLRP3炎症小体的活化,达到治疗肾脏疾病的目的.因此,针对肾脏疾病中NLRP3炎症小体相关的作用机制及其干预性的研究可能是今后重点发展的方向之一.     

磷酸化在NLRP3炎症小体活化中的调控作用（英文）

NLRP3是位于细胞质中的模式识别受体,属于NOD样受体家族.在多种危险相关分子模式和病原体相关分子模式的激活下,NLRP3受体通过招募接头蛋白ASC和半胱氨酸蛋白酶原caspase-1形成一个多聚蛋白复合物,称之为NLRP3炎症小体.NLRP3炎症小体的主要功能是通过促进免疫应答清除病原微生物和危险信号,维持体内平衡.但是,NLRP3炎症小体异常活化又会引发多种炎症性疾病.因此,其活化必须受到严格调控.近期,多种激酶和磷酸酶被报道调控NLRP3炎性小体活化,这表明磷酸化在调控炎症小体活化中起着至关重要的作用.在本文中,我们概述了多种激酶和磷酸酶如何调控NLRP3炎症小体活化,并概述了磷酸化在NLRP3炎症小体活化中的调控作用.此外,我们还总结了靶向NLRP3相关激酶或磷酸酶治疗炎症小体相关疾病的潜在药用化合物.     

NLRP3炎症小体在牛种布鲁氏菌2308和RB51侵染人巨噬细胞THP-1过程中作用的初步研究

为了探索NLRP3炎症小体在布鲁氏菌侵染宿主细胞过程中的作用,以牛种布鲁氏菌强毒株2308、弱毒株RB51侵染人巨噬细胞THP-1,用实时荧光定量PCR方法探索布鲁氏菌引起宿主细胞中NLRP3炎症小体及相关细胞因子的变化情况。结果表明:在布鲁氏菌侵染THP-1细胞后0-24 h,NLRP3炎症小体在转录水平上总体呈现先下降后上升的趋势,THP-1细胞形态随着侵染时间的延长变得不规则,且出现聚集现象。强毒株2308对NLRP3炎症小体相关基因转录水平和THP-1细胞形态变化的影响均强于弱毒株RB51。这表明布鲁氏菌在感染初期有短暂抑制炎症小体的能力,这可能是布鲁氏菌逃避巨噬细胞杀灭作用的一种策略。     

布鲁氏菌感染诱发巨噬细胞炎症反应的初步研究

为研究NLRP3炎症小体在布鲁氏菌侵染小鼠巨噬细胞过程中活化介导的炎症反应,建立牛种布鲁氏菌2308株侵染小鼠巨噬细胞RAW264.7的模型,侵染比例100∶1(细菌∶细胞),RT-PCR技术检测细菌侵染过程中NLRP3炎症小体相关分子NLRP3和Caspase-1 m RNA的变化水平;Western blot分析NLRP3和Caspase-1在蛋白水平的变化;ELISA检测感染细胞上清中炎症因子IL-18和IL-1β的释放量。结果表明:与对照组相比布鲁氏菌感染小鼠巨噬细胞后NLRP3和Caspase-1 m RNA和蛋白表达水平显著增加(P0.05),炎性因子IL-1β和IL-18的含量也显著升高(P0.05)。结论:布鲁氏菌感染可激活NLRP3炎症小体,为进一步研究布鲁氏菌感染引发致病机制奠定理论基础。     

NLRP3炎症小体抑制剂研究进展

NLRP3是一种重要的胞内模式识别受体,可以与ASC及pro-caspase-1形成炎症小体,促进IL-1β和IL-18等炎性介质的成熟和分泌,从而促进炎症反应.NLRP3炎症小体活化失调与多种人类重大疾病密切相关,如痛风、动脉粥样硬化、神经退行性疾病和2型糖尿病等.因此NLRP3炎症小体是上述疾病的潜在干预靶点,许多NLRP3炎症小体抑制剂对相关疾病表现出良好的预防或者治疗效果.本文对NLRP3炎症小体抑制剂最近的研究进展进行简要综述.     

NLRP3、AIM2、IFI16炎症小体在慢性乙型病毒性肝炎患者PBMC中的活化水平和与HBV感染的相关性分析

目的:探讨乙肝病毒(HBV)是否激活了慢性乙型病毒性肝炎(CHB)患者外周血单个核细胞(PBMCs)内核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、黑色素瘤缺乏因子2(AIM2)和干扰素诱导蛋白16(IFI16)炎症小体,分析HBV影响炎症小体活化的可能机制.方法:收集感染内科临床确诊CHB患者35例.同时选取健康住院医师28例为对照.以常规淋巴细胞分层液密度梯度离心法分离健康对照组和CHB患者组静脉血得到PBMCs,采用逆转录、实时荧光定量PCR检测CHB患者组和健康对照组PBMCs NLRP3、AIM2、IFI16、凋亡相关的斑点样蛋白(ASC)、半胱天冬酶1(CASP1)、IL-1β、IL-18 mRNA表达水平,ELISA法检测两组血清中IL-1β蛋白分泌水平.结果:CHB患者组和健康对照组PBMCs ASC、NLRP3、AIM2、IL-1β、IL-18 mRNA表达水平及两组血清IL-1β蛋白分泌水平无显著性差异.CHB患者组PBMCs IFI16、CASP1 mRNA表达水平显著上调,且IFI16 mRNA表达水平与患者血清HBV DNA载量显著正相关(r=0.699 8,P0.01).结论:慢性HBV感染未导致CHB患者PBMCs NLRP3、AIM2炎症小体的活化;尽管HBV DNA可能诱导了CHB患者IFI16炎症小体的高表达,但通过抑制pro-caspase-1的活化、IL-1β的表达,HBV阻断了IFI16炎症小体的活化效应.     

慢病毒感染方法构建稳定干涉PDRG1的HeLa细胞系

PDRG1(p53 and DNA-damage regulated 1)是实验室通过文库筛选发现的参与NF-kB信号通路调控的一个新基因。已知PDRG1在多种肿瘤中高表达,并参与p53信号通路;同时该基因受UV以及基因毒性等刺激调控。但其在NF-κB信号通路中作用尚未见报道,为了深入研究PDRG1对NF-κB信号通路的调控机理,构建了稳定干涉PDRG1的HeLa细胞系。选择了基于慢病毒载体pLKO.1的感染体系,该慢病毒体系可以同时感染分裂期与非分裂期的细胞,将目的基因干涉序列稳定整合至靶细胞基因组中;再经过抗生素压力筛选后在短时间内获得稳定干涉目的基因表达的细胞株。设计合成PDRG1干涉序列并克隆至pLKO.1载体,转染病毒包装细胞293TN后收集慢病毒上清感染HeLa细胞系,进一步经过嘌呤霉素压力筛选成功获得稳定表达PDRG1干涉序列的细胞株。该稳定细胞株的建立为PDRG1的功能研究提供了必要的实验工具。     

NLRP3参与PGE2诱导的宫颈癌发生

宫颈癌是最常见的妇科恶性肿瘤之一,在全球女性恶性肿瘤中其发病率仅次于乳腺癌,其中80%确诊时已是浸润癌。炎症是机体细胞受到多因素刺激后产生的局部或全身性应答反应。目前对炎症-肿瘤相互影响的研究成为人类恶性肿瘤研究中不可忽视的重要环节。文章就炎症小体NLRP3参与了PGE2诱导的宫颈癌发生的机制研究做一综述。     

GNL3对脑胶质瘤干细胞的调控研究

肿瘤干细胞是一小群特异的肿瘤细胞,被认为是肿瘤发生,耐药和复发的主要原因。GNL3(Guanine nucleotide-binding protein-like 3) 是MMR1/HSR1 GTP结合蛋白家族成员,在干细胞增殖中发挥重要作用。本实验室通过质谱筛选,发现GNL3蛋白在脑胶质瘤干细胞(Glioma stem cell,GSC)中特异性高表达。目前关于GNL3在脑胶质瘤干细胞中的功能及其作用机制未见文献报道。为了研究GNL3在GSC中的功能,我们利用慢病毒感染细胞体系,在GSC中应用3个不同的靶序列对GNL3基因的表达进行稳定干涉;利用Western Blot对GNL3的干涉效果进行检测。实验结果表明,在稳定敲低GNL3表达的GSC中,胶质瘤干细胞的细胞活力和肿瘤细胞球(Tumor sphere)的形成能力明显受到抑制,表明GNL3蛋白对GSC的增殖能力及自我更新能力具有重要调控,提示GNL3在胶质母细胞瘤的肿瘤发生过程中发挥一定作用。     

IITZ-01 activates NLRP3 inflammasome by inducing mitochondrial damage

NLRP3 inflammasome can be activated by a variety of pathogen activators (including components of bacteria, viruses and fungi) or “danger signals” (including abnormal metabolites and environmental components), so its activation mechanism is extremely complex. IITZ-01 is a lysosomotropic molecule that can disrupt lysosomal functions. We found that IITZ-01 can activate inflammasome at a low concentration. Then, we determined that IITZ-01 is a specific activator of NLRP3 inflammasome through inflammasome stimulation, ELISA, Western blot and other experiments. Mechanistically, NLRP3 inflammasome activation induced by IITZ-01 is independent of direct binding and ion flow but dependent on mitochondrial damage and mROS accumulation. This study suggests that a lysosomotropic compound can activate NLRP3 inflammasome by impairing mitochondrial functions.     

沉默SEMA3A基因对胶质瘤细胞U251增殖和转移的影响

探讨了SEMA3A基因在恶性胶质瘤细胞U251迁移和侵袭能力中的作用, 及其用于胶质瘤临床治疗的可行性. 用特异识别SEMA3A基因的短发卡RNA(short hairpin RNA,shRNA)片段与真核表达载体pFH-GFP-L连接, 再与辅助质粒联用来包装慢病毒. 通过荧光显微镜观察感染胶质瘤细胞U251的感染效率. 通过实时定量PCR技术和Western-blot技术验证了U251细胞中SEMA3A基因的沉默效果. 通过MTT法、PI染色法和Transwell小室分别检测了U251细胞增殖、细胞周期和运动能力的变化. 结果表明, SEMA3A-shRNA慢病毒感染U251能有效下调SEMA3A基因的表达水平(P <0.01), 使U251细胞的增殖能力、迁移和侵袭能力明显降低(P <0.05), 细胞大量阻滞在G2/M期, 并促进了细胞凋亡(P <0.05).     

A role for mitochondria in NLRP3 inflammasome activation

An inflammatory response initiated by the NLRP3 inflammasome is triggered by a variety of situations of host 'danger', including infection and metabolic dysregulation. Previous studies suggested that NLRP3 inflammasome activity is negatively regulated by autophagy and positively regulated by reactive oxygen species (ROS) derived from an uncharacterized organelle. Here we show that mitophagy/autophagy blockade leads to the accumulation of damaged, ROS-generating mitochondria, and this in turn activates the NLRP3 inflammasome. Resting NLRP3 localizes to endoplasmic reticulum structures, whereas on inflammasome activation both NLRP3 and its adaptor ASC redistribute to the perinuclear space where they co-localize with endoplasmic reticulum and mitochondria organelle clusters. Notably, both ROS generation and inflammasome activation are suppressed when mitochondrial activity is dysregulated by inhibition of the voltage-dependent anion channel. This indicates that NLRP3 inflammasome senses mitochondrial dysfunction and may explain the frequent association of mitochondrial damage with inflammatory diseases.     

Novel role of PKR in inflammasome activation and HMGB1 release

The inflammasome regulates the release of caspase activation-dependent cytokines, including interleukin (IL)-1β, IL-18 and high-mobility group box 1 (HMGB1). By studying HMGB1 release mechanisms, here we identify a role for double-stranded RNA-dependent protein kinase (PKR, also known as EIF2AK2) in inflammasome activation. Exposure of macrophages to inflammasome agonists induced PKR autophosphorylation. PKR inactivation by genetic deletion or pharmacological inhibition severely impaired inflammasome activation in response to double-stranded RNA, ATP, monosodium urate, adjuvant aluminium, rotenone, live Escherichia coli, anthrax lethal toxin, DNA transfection and Salmonella typhimurium infection. PKR deficiency significantly inhibited the secretion of IL-1β, IL-18 and HMGB1 in E. coli-induced peritonitis. PKR physically interacts with several inflammasome components, including NOD-like receptor (NLR) family pyrin domain-containing 3 (NLRP3), NLRP1, NLR family CARD domain-containing protein 4 (NLRC4), absent in melanoma 2 (AIM2), and broadly regulates inflammasome activation. PKR autophosphorylation in a cell-free system with recombinant NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC, also known as PYCARD) and pro-caspase-1 reconstitutes inflammasome activity. These results show a crucial role for PKR in inflammasome activation, and indicate that it should be possible to pharmacologically target this molecule to treat inflammation.     

Inflammasomes in health and disease

Inflammasomes are a group of protein complexes built around several proteins, including NLRP3, NLRC4, AIM2 and NLRP6. Recognition of a diverse range of microbial, stress and damage signals by inflammasomes results in direct activation of caspase-1, which subsequently induces secretion of potent pro-inflammatory cytokines and a form of cell death called pyroptosis. Inflammasome-mediated processes are important during microbial infections and also in regulating both metabolic processes and mucosal immune responses. We review the functions of the different inflammasome complexes and discuss how aberrations in them are implicated in the pathogenesis of human diseases.     

羟基磷灰石纳米粒子运载Stat3 shRNA对鼠胶质瘤C6细胞的促凋亡效应

目的探讨羟基磷灰石纳米粒子运载Stat3 shRNA对鼠胶质瘤C6细胞的促凋亡作用,并探讨相关机制.方法羟基磷灰石纳米粒子包被的Stat3 shRNA转染到C6胶质瘤细胞内,MTT法检测细胞增殖情况,应用流式细胞术及吖啶橙染色观察细胞周期分布及凋亡情况,TUNEL染色观察细胞的凋亡及增殖情况.结果羟基磷灰石纳米粒子运载Stat3 shRNA转染C6细胞后,呈时间依赖性抑制C6细胞生长和增殖.通过流式细胞术检测证实:该质粒可使细胞阻滞在细胞周期的G0/G1期,细胞凋亡率明显增加(P<0.05),与对照组比较差异有统计学意义;吖啶橙及TUNEL染色发现其明显促进细胞凋亡(P<0.05),与对照组比较差异有统计学意义;结论羟基磷灰石纳米粒子运载Stat3 shRNA体外可明显抑制胶质瘤C6细胞增殖,并促进其凋亡,是治疗胶质瘤较理想的方法.     

NLRP6 negatively regulates innate immunity and host defence against bacterial pathogens

Members of the intracellular nucleotide-binding and oligomerization domain (NOD)-like receptor (NLR) family contribute to immune responses through activation of nuclear factor-κB (NF-κB), type I interferon and inflammasome signalling. Mice lacking the NLR family member NLRP6 were recently shown to be susceptible to colitis and colorectal tumorigenesis, but the role of NLRP6 in microbial infections and the nature of the inflammatory signalling pathways regulated by NLRP6 remain unclear. Here we show that Nlrp6-deficient mice are highly resistant to infection with the bacterial pathogens Listeria monocytogenes, Salmonella typhimurium and Escherichia coli. Infected Nlrp6-deficient mice had increased numbers of monocytes and neutrophils in circulation, and NLRP6 signalling in both haematopoietic and radioresistant cells contributed to increased susceptibility. Nlrp6 deficiency enhanced activation of mitogen-activated protein kinase (MAPK) and the canonical NF-κB pathway after Toll-like receptor ligation, but not cytosolic NOD1/2 ligation, in vitro. Consequently, infected Nlrp6-deficient cells produced increased levels of NF-κB- and MAPK-dependent cytokines and chemokines. Thus, our results reveal NLRP6 as a negative regulator of inflammatory signalling, and demonstrate a role for this NLR in impeding clearance of both Gram-positive and -negative bacterial pathogens.     

Crucial role for the Nalp3 inflammasome in the immunostimulatory properties of aluminium adjuvants

Aluminium adjuvants, typically referred to as 'alum', are the most commonly used adjuvants in human and animal vaccines worldwide, yet the mechanism underlying the stimulation of the immune system by alum remains unknown. Toll-like receptors are critical in sensing infections and are therefore common targets of various adjuvants used in immunological studies. Although alum is known to induce the production of proinflammatory cytokines in vitro, it has been repeatedly demonstrated that alum does not require intact Toll-like receptor signalling to activate the immune system. Here we show that aluminium adjuvants activate an intracellular innate immune response system called the Nalp3 (also known as cryopyrin, CIAS1 or NLRP3) inflammasome. Production of the pro-inflammatory cytokines interleukin-1beta and interleukin-18 by macrophages in response to alum in vitro required intact inflammasome signalling. Furthermore, in vivo, mice deficient in Nalp3, ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain) or caspase-1 failed to mount a significant antibody response to an antigen administered with aluminium adjuvants, whereas the response to complete Freund's adjuvant remained intact. We identify the Nalp3 inflammasome as a crucial element in the adjuvant effect of aluminium adjuvants; in addition, we show that the innate inflammasome pathway can direct a humoral adaptive immune response. This is likely to affect how we design effective, but safe, adjuvants in the future.