白藜芦醇减轻脂多糖诱导的小鼠急性肺损伤

目的观察白藜芦醇在脂多糖(LPS)诱导的急性肺损伤(ALI)小鼠中的作用,以及白藜芦醇对小鼠肺组织NOD样受体蛋白3(NLRP3)表达的影响。方法将小鼠分为对照组,ALI模型组(经气管滴注5 mg/kg的LPS建立小鼠ALI模型),白藜芦醇干预组(经腹腔注射30 mg/kg白藜芦醇,2 h后,经气管滴注5 mg/kg的LPS)。检测小鼠呼吸功能;HE染色及病理评分观察小鼠肺组织形态的变化;检测支气管肺泡灌洗液(BALF)中总蛋白、总细胞数及中性粒细胞数目,并观察中性粒细胞的活化; ELISA检测BALF中IL-1β和IL-18的蛋白水平;real-time PCR检测小鼠肺组织IL-1β、IL-18、nlrp3、asc及pro-caspase-1 mRNA的表达;Western blot检测肺组织IκB的蛋白表达。结果白藜芦醇可改善ALI小鼠的呼吸功能;减轻LPS诱导的肺部病理损伤;降低ALI小鼠BALF中IL-1β和IL-18的蛋白水平(P0.05);减少ALI小鼠肺组织NLRP3、ASC、pro-caspase-1的表达,增加IκB的蛋白表达(P0.05)。结论白藜芦醇可能抑制NLPR3炎性反应小体活化后产物的表达,最终可减轻LPS诱导的小鼠ALI。     

TXNIP/NLRP3在脓毒症所致ALI/ARDS患者外周血中的表达

为探讨硫氧还蛋白互作蛋白(thioredoxin interacting protein, TXNIP)/NOD样受体家族含pyrin结构域蛋白3(NOD-like receptor family pyrin domain-containing protein 3, NLRP3)炎症小体通路在急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS)发病机制中的作用,收集2017年1月—2018年12月因脓毒症导致急性肺损伤(acute lung injury, ALI)/ARDS重症住院的患者及同期健康体检者各40例为研究对象,其中病例组按照采血时间分为治疗D0、D3、D7组。采用qRT-PCR测定研究对象PBMC中NLRP3和TXNIP mRNA表达水平,同时采用Western blotting测定PBMC中NLRP3和TXNIP的蛋白表达水平。结果显示,病例治疗D0组、D3组、D7组的TXNIP、NLRP3 mRNA和TXNIP、NLRP3蛋白表达水平均显著高于对照组(均P0.05);病例治疗D7组TXNIP、NLRP3 mRNA表达水平较治疗D0组显著降低(均P0.05);治疗D3组的TXNIP、NLRP3 mRNA表达水平较治疗D0组显著降低(均P0.05);病例组TXNIP、NLRP3 mRNA水平均与序贯器官衰竭估计评分(sequential organ failure assessment, SOFA)呈正相关(r≥0.782)。由此,TXNIP/NLRP3炎症小体通路可能参与脓毒症所致ALI/ARDS的发生、发展。     

NLRP3炎性小体在缺血再灌注损伤治疗中作用的研究进展

NLRP3 (NLRP3)炎性小体作为组成先天免疫系统的蛋白复合体，可通过调节IL-1β和IL-18的成熟释放介导炎性反应，是机体发生多种病理损伤的基础。缺血/再灌注损伤(I/RI)时产生的多种损伤因子均可激活NLRP3炎性小体，导致IL-1β和IL-18的过度释放，进而引起炎性级联反应使各组织器官的损伤加重。而抑制NLRP3炎性小体活化已成为减轻器官I/RI的有效方法。因此，探究NLRP3炎性小体介导I/RI的详细作用机制，可以为器官I/RI的防治提供理论依据。     

急性肺损伤/急性呼吸窘迫综合征相关微RNA研究进展

微RNA(miRNA)是一组高度保守的长度约22个核苷酸的非编码RNA,通过靶定相应的互补序列导致mRNA的沉默或者抑制翻译以调节基因和蛋白的表达。急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)的发病机制错综复杂,涉及失控性炎症反应、细胞凋亡及肺泡液体清除异常等多个层面,而且各个层面相互影响形成复杂的细胞网络和细胞因子网络,其通过不同的信号转导通路调控机体炎症反应。ALI发病过程中miRNA表达异常,miRNA可通过与靶mRNA部分结合在转录和转录后水平调节靶基因表达,参与ALI的整个发病过程。本文总结了国内外ALI发病过程中相关miRNA的研究进展,旨在寻找和验证miRNA在ALI炎症激活和信号转导途径中的作用,为ALI的诊疗提供新靶点。     

急性呼吸窘迫综合征的药物治疗

急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的防治是多途径、综合性的救治过程.目前尚无治疗急性肺损伤(acute lung injury,ALI)/ARDS的特效药物,对其有缓解作用的药物主要针对其的急性渗出期、炎症反应或氧化损伤以及纤维增生期.联合多种药理因素...     

Toll 样受体信号转导通路与急性肺损伤的研究进展

急性肺损伤(ALI)是由感染性和非感染性的炎症刺激因子启动的细胞内“瀑布式”反应所产生的,是一种具有高发病率和死亡率的急性炎症性疾病,其进一步发展将演变为急性呼吸窘迫综合征(ARDS)。ALI作为一种复杂的临床综合征,发病率和病死率很高,目前发病机制仍不完全明确,大量研究表明细胞因子的过度表达及其相互作用是发生ALI的根本原因。Toll样受体(TLRs)是一类在先天免疫系统中起重要作用并参与炎症过程的跨膜蛋白,可识别外源性病原体或细胞损伤。近年来研究发现,TLRs在调节ALI后的炎症和修复机制方面扮演着重要的角色,是一个潜在的治疗靶点。本文将就TLRs在急性肺损伤中的研究进展作一综述。     

干细胞旁分泌效应在ALI/ARDS治疗中的研究进展

急性肺损伤(acute lung injury,ALI)以及它的严重形式——急性呼吸窘迫综合征(acute respiratorydistress syndrome,ARDS)是危重病人发病和死亡的重要原因之一,最近2个世纪以来,死亡率仍在36%～44%左右。ALI/ARDS的病因众多,发病机制十分复杂,涉及的环节多,受损的靶细胞多,主要涉及的环节有:炎症反应失控、细胞损伤与修复、细胞凋     

肺血管内皮细胞分泌功能的改变与急性肺损伤/急性呼吸窘迫综合征

急性肺损伤(acute lung injury,ALI)/急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS)是临床上常见的急危重症,病死率高达25%~45%,治疗上主要限于器官功能与全身支持治疗,尤其是呼吸支持治疗,“等待”肺损伤的缓解。在ARDS发病机制中肺血管内皮细胞(pulmonary vascular endothelial cell,PVEC)既是受损的主要靶细胞,更是活跃的炎症和效应细胞,血管内皮细胞(vascular endothelial cell,VEC)的激活和损伤程度与ARDS预后密切相关。本文将主要阐述ALI/ARDS发病机制中PVEC部分分泌功能的改变。     

急性肺损伤/急性呼吸窘迫综合征与NF-κB信号转导关系的研究进展

急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)是临床上最常见的急危重症,其发病机制错综复杂,缺乏主动性治疗措施,病死率高。研究表明,核因子κB(NF-κB)为一种诱导型核转录因子,在ALI/ARDS发展过程中发挥极为广泛的功能,并与炎症反应具有密切的关系。现就ALI/ARDS、NF-κB信号转导通路及两者的关系作一简要的论述。     

NLRP3炎性小体在动脉粥样硬化发生发展中的作用

NLRP3炎性小体是一种包含胞内受体(主要是NOD样受体)、半胱天冬氨酸前体和凋亡相关斑点样蛋白的蛋白质复合体.该复合体最初只是被描述为一种影响感染和炎症过程的复合体,它的活化引起半胱天冬氨酶-1的激活并剪切加工底物白细胞介素-1β(interleukin-1β,IL-1β)和白细胞介素-18(interleukin-18,IL-18),从而引起炎症反应;此外,炎性小体的激活过程对有氧糖酵解(瓦伯格效应,Warburg effect)有着重要的影响,这同样可以促进炎症的发生.随后的证据表明炎性小体的活化还影响很多代谢紊乱包括动脉粥样硬化(atherosclerosis, AS)、2型糖尿病、痛风和肥胖等.本综述将探讨AS与炎症、NLRP3炎性小体活化的关联性,以及瓦伯格效应如何关联炎症反应及炎性小体的激活.     

MiR-24 inhibits inflammatory responses in LPS-induced acute lung injury of neonatal rats through targeting NLRP3

Inflammation plays an important role in the development of acute lung injury (ALI) in preterm infants. Despite the critical role of microRNA in inflammatory response, little is known about its function in ALI. In this study, we investigate the role of MicroRNA-24 (miR-24) in lipopolysaccharide (LPS) induced neonatal rats ALI and its potential mechanism. LPS was used to induce ALI neonatal animal model. miR-24 expression in the lung tissues of LPS-challenged neonatal rats was detected by qPCR. Proinflammatory factors, including tumor necrosis factor-alpha (TNF-α), IL-1β, IL-18 in the bronchoalveolar lavage fluid and lung tissues of LPS-challenged neonatal rats were measured by qRT-PCR and western blot, respectively. The mRNA levels of surfactant protein A (SP-A) and D (SP-D) was measured by qRT-PCR. Direct binding of miR-24 and pyrin domain-containing 3(NLRP3) were determined by dual luciferase assay. The levels of NLRP3, apoptosis-associated speck-like protein containing a C?terminal caspase recruitment domain (ASC) and caspase-1 protein expression were detected by immunohistochemistry (IHC) staining and western blot, respectively. Our data indicated that LPS-induced lung injury in neonatal rats and resulted in significant downregulated of miR-24 expression. Overexpression of miR-24 significantly reduced LPS-induced lung damage and decreased the release of proinflammatory cytokine TNF-α, IL-6, IL-1β and SP-A, SP-D expression induced by LPS. In addition, miR-24 inhibited the expression of NLRP3 by directly targeting to the CDS region of NLRP3 mRNA. Furthermore, miR-24 overexpression attenuated lung inflammation and deactivated the NLRP3/caspase-1/IL-1β pathway in LPS-challenged neonatal rats. These data show that miR-24 alleviated inflammatory responses in LPS-induced ALI via targeting NLRP3.     

MD-2 regulates LPS-induced NLRP3 inflammasome activation and IL-1beta secretion by a MyD88/NF-κB-dependent pathway in alveolar macrophages cell line

Myeloid differentiation protein 2 (MD-2) is required in the recognition of lipopolysaccharide (LPS) by toll-like receptor 4 (TLR4), and participates in LPS-induced alveolar macrophage (AM) inflammation during acute lung injury (ALI). Activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome aggravates inflammation in LPS-induced ALI. However, there is currently little known about the relationship between MD-2 signaling and the NLRP3 inflammasome. This study showed that NLRP3 expression, IL-1beta (IL-1β) secretion, and pyroptosis were up-regulated after LPS stimulation in the NR8383 AM cell-line. MD-2 gene knock-down reduced LPS-induced mRNA and protein expression of NLRP3 and IL-1β secretion in NR8383 cells, and inhibited the MyD88/NF-κB signaling pathway. Conversely, over-expression of MD-2 not only heightened NLRP3, MyD88, and NF-κB p65 protein expression, it also aggravated the LPS-induced inflammatory response. Furthermore, the NF-κB inhibitor SN50 had a beneficial role in decreasing NLRP3 and caspase-1 mRNA and protein expression. The observations suggest that MD-2 helps to regulate LPS-induced NLRP3 inflammasome activation and the inflammatory response in NR8383 cells, and likely does so by affecting MyD88/NF-κB signaling.     

NLRP3炎症小体在MS/EAE发病机制中的作用及其靶向治疗

多发性硬化症(multiple sclerosis,MS)是由免疫细胞攻击中枢神经系统(central nervous system,CNS)而造成的一种自身免疫性疾病,其具有神经元脱髓鞘、神经胶质细胞增生和轴突损伤等病理特征[1]。NLRP3炎症小体作为一种能识别病原体和危险信号的传感器,近年来被发现与许多自身免疫性疾病的发病关系密切[2]。本文从NLRP3炎症小体激活的主要途径出发,综述了NLRP3炎症小体在MS及其动物模型——实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)发病中的作用以及靶向治疗研究进展。     

Ginsenoside Rg1 alleviates acute liver injury through the induction of autophagy and suppressing NF-κB/NLRP3 inflammasome signaling pathway

Background: Severe hepatitis is a common cause of chronic or acute liver disease and autophagy might play an important role in cellular response to inflammation and injury. It has been reported that Ginsenoside-Rg1 (G-Rg1) has strong hepatoprotective effects for acute liver injury, but its protective mechanisms have not yet been elucidated. This study aims to explore the detailed molecular mechanisms of G-Rg1 on acute liver injury via autophagy.Methods: The role of G-Rg1 by autophagic induction was studied in the mouse model of acute liver injury which induced by carbon tetrachloride (CCl4). Liver function, inflammatory reaction and apoptosis were detected when autophagy has been inhibited by 3-MA or stimulated by RPA. MCC950 and ATP were applied to investigate the role of NLRP3 inflammasome in acute liver injury. The differential expression of NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β, IL-18, LC3-I, LC3-II, Beclin-1, PINK1 and Parkin have been detected by the quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.Results: G-Rg1 could decrease ALT, AST, TNF-α, IL-1β and IL-6 in mice with CCl4-induced acute liver injury. The change of autophagy and apoptosis after the treatment of 3-MA or RPA demonstrated that the autophagy played a key role in the protective effect of G-Rg1 in acute liver injury. The enhancement of G-Rg1 promoted-autophagy resulted in the significant decrease in NF-κB, NLRP3 inflammasome, caspase 1, caspase 3, IL-1β and IL-18, which suggesting that NF-κB/NLRP3 inflammasome signaling pathway was associated with the autophagy induced by G-Rg1 in acute liver injury.Conclusion: G-Rg1 ameliorated acute liver injury via the autophagy, which may be related to NF-κB/NLRP3 inflammasome signaling pathway.     

Sensing damage by the NLRP3 inflammasome

The NLRP3 inflammasome is activated in response to a variety of signals that are indicative of damage to the host including tissue damage, metabolic stress, and infection. Upon activation, the NLRP3 inflammasome serves as a platform for activation of the cysteine protease caspase-1, which leads to the processing and secretion of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18. Dysregulated NLRP3 inflammasome activation is associated with both heritable and acquired inflammatory diseases. Here, we review new insights into the mechanism of NLRP3 inflammasome activation and its role in disease pathogenesis.     

IL-27 is Elevated in Acute Lung Injury and Mediates Inflammation

Cytokines play a critical role in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Here we investigated whether IL-27 was elevated in patients with ALI/ARDS and its potential clinical significance. Bronchoalveolar lavage (BAL) and serum samples were obtained from 58 ALI/ARDS patients, and 25 control healthy volunteers. IL-27 and other inflammatory mediators were measured in BAL and serum by ELISA. Besides, a mouse model of cecal ligation and puncture (CLP)-induced lung inflammation/injury was established, and serum, BAL fluid and tissues were collected for analyses in the presence or absence of IL-27 neutralizing antibodies. BAL IL-27 was found to be significantly higher in patients with ALI/ARDS than that in controls, particularly of pulmonary origin; serum IL-27 was also significantly higher. Increased IL-27 was associated with markers of inflammation, and correlated with disease severity of patients in ALI/ARDS. In a mouse model of CLP-induced lung inflammation/injury, elevated IL-27 levels were observed in the lung, serum, and BAL fluids. IL-27 neutralizing antibody treatment reduced pulmonary inflammation and lung injury and improved mouse survival in response to CLP. Therefore, IL-27 is a critical cytokine in ALI/ARDS and inhibition of IL-27 may open a promising approach for ALI/ARDS patients.     

The NLRP3/ASC/Caspase-1 axis regulates IL-1β processing in neutrophils

Neutrophils play a pivotal role in the defense against bacterial, viral and fungal infections and are important mediators in the acute inflammatory response. At the same time, neutrophils are also in volved in sterile inflammatory responses that are triggered by endogenous ligands. A series of immediate effector functions and the expression of proinflammatory genes enable neutrophils to initiate the immune response against the injurious agent. Among these, interleukin-1β (IL-1β) plays a key role in the orchestration of the inflammatory response. Induction of IL-1β expression leads to production of cytosolic pro-IL-1β, which requires further processing by a proteolytic cleavage event. Caspase-1 was initially identified as the main IL-1β-converting enzyme, and the upstream events leading to caspase-1 activation were identified as so-called inflammasome complexes. Up to now, the inflammasome system has mainly been studied in macrophages, whereas the inflammasome was thought to play a redundant or no role in the cell intrinsic processing of pro-IL-1β in neutrophils. Here, we identify the expression of the components of the NLRP3 inflammasome complex in neutrophils and show that the NLRP3 inflammasome pathway is indeed operational in neutrophils. Our findings establish the NLRP3 inflammasome as a key step in the secretion of matured IL-1β by neutrophils.     

ALI/ARDS抗炎治疗研究的策略与展望

急性肺损伤(acute lung injury, ALI)既是呼吸道重大疫病(如SARS、禽流感)的病理基础,也是全身炎症反应综合征(systemic inflammatory response syndrome,SIRS)时最易出现的组织损伤[1].ALI进一步发展即为急性呼吸窘迫综合征(acute respiratory distress syndrome, ARDS).随着失控性的炎症反应(uncontrolled inflammatory response)引发多器官功能障碍综合征(multipile organs disfunction syndrome, MODS)学说的提出,人们对ALI／ARDS 认识转向对炎症发生、调控的认识,参与炎症反应的炎症细胞和细胞因子则成为研究的热点[2-5].     

NLRP3 inflammasome activation regulated by NF-κB and DAPK contributed to paraquat-induced acute kidney injury

Paraquat can result in dysfunction of multiple organs after ingestion in human. However, the mechanisms of nucleotide-binding domain and leucine-rich repeat containing protein 3 (NLRP3) inflammasome activation in acute kidney injury have not been clearly demonstrated. The aim of this study was to determine the effect of NLRP3 inflammasome activation and its regulation by nuclear factor-kappa B (NF-κB) and death-associated protein kinase (DAPK). Male Wistar rats were treated with intraperitoneal injection of paraquat at 20 mg/kg, and NF-κB inhibitor BAY 11-7082 was pretreated at 10 mg/kg 1 h before paraquat exposure. Additionally, rat renal tubular epithelial cells (NRK-52E) were transfected with small interfering RNA (siRNA) against DAPK to evaluate its role in NLRP3 inflammasome activation. DAPK and NLRP3 inflammasome were evaluated by immunohistochemistry staining or Western blot; the pro-inflammatory cytokines including tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were measured via ELISA. The results showed that NF-κB, DAPK, and NLRP3 inflammasome were activated in paraquat (PQ)-treated rat kidney; the secretion of pro-inflammatory cytokines was significantly increased. These toxic effects were attenuated by NF-κB inhibitor. Besides, the activation of NLRP3 inflammasome and secretion of IL-1β and IL-18 in paraquat-treated rat renal tubular epithelial cells were inhibited by siRNA against DAPK. In conclusion, NLRP3 inflammasome activation regulated by NF-κB and DAPK played an important role in paraquat-induced acute kidney injury.