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     

肾上腺髓质素参与大鼠急性肺损伤的发病

急性肺损伤(acute lung injury,ALI)是指由不同原因引起的包括肺泡上皮、肺毛细血管内皮和肺间质的急性弥漫性损害,临床治疗困难。ALI发病机制十分复杂,近年研究发现,血管内皮细胞及相关因子在ALI发病中起着重要的作用。肾上腺髓质素(adrenomedullin,Adm)是一种新的血管     

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。     

慢性酗酒与急性肺损伤/急性呼吸窘迫综合征

急性肺损伤/急性呼吸窘迫综合征(acute lung injury/accute respiratory distress syndrome,ALI/ARDS)是在非心源性疾病过程中.     

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...     

NOD样受体蛋白3炎症小体在急性肺损伤/急性呼吸窘迫综合征中的作用机制研究进展

急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)是由多种非心源性肺内外因素引起的急性进行性呼吸衰竭,发病核心为过度放大或失控的炎症反应,目前没有特效的治疗药物.NOD样受体蛋白3(nucleotide-binding domain (NOD)-like receptor protein 3,NLRP3)炎症小体是细胞受到刺激时形成的多蛋白复合体,活化后导致细胞焦亡及IL-1β、IL-18等产生,在多种感染性、炎症性疾病中起重要作用.引起肺损伤的多种因素均可导致NLRP3炎症小体形成、活化,有研究提示,与ALI/ARDS中的过度炎症反应有关.因而深入研究NLRP3炎症小体在ALI/ARDS中的作用,对于进一步阐明ALI/ARDS的发病机制有重要意义,甚至有望成为治疗ALI/ARDS的新靶点.     

凝血和纤溶失衡在急性肺损伤中的作用

急性肺损伤(acute lung injury,ALI),以肺泡上皮细胞和血管内皮屏障损伤、急性炎症反应、富含蛋白的肺水肿为特征,是一种临床常见的危重病症,可进一步发展为急性呼吸窘迫综合症(acute respiratory distress syndrome,ARDS).     

早期无创正压通气对重症急性胰腺炎合并肺损伤的保护作用机制

重症急性胰腺炎（SAP）所致急性肺损伤（ALI）/急性呼吸窘迫综合征（ARDS）是SAP早期死亡的主要原因,是肺外型 ARDS 的典型代表,已有研究证实早期无创正压通气对 SAP所致 ARDS是一种行之有效治疗方法。本文主要就早期无创正压通气对重症急性胰腺炎合并肺损伤的保护作用及其作用机制研究情况进行综述,为早期无创正压通气用于重症急性胰腺炎合并肺损伤治疗提供依据。     

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。     

硫辛酸对急性肺损伤保护作用

目的：探讨代谢性抗氧化剂硫辛酸(LA)对内毒素(LPS)诱发大鼠急性肺损伤/急性呼吸窘迫综合征(ALI/ARDS)模型的保护机制,为急性肺损伤的治疗提供新的思路和方法。方法将ALI/ARDS大鼠分为正常对照组(生理盐水(NS)组)、ALI/ARDS模型组(脂多糖(LPS组)、LA干预组(LA组)和谷胱甘肽干预组(GSH组),每组各10只。注射后1、2、4和6h观察血清肿瘤坏死因子(TNF-A)水平,6 h后处死大鼠,测定动脉血氧分压(PaO2)、血清脂过氧化物水平(LPO)、肺湿干比(W/D)、肺泡灌洗液(BALF)中蛋白浓度和TNF-水平。结果LA组和GSH组PaO2水平较LPS组明显增高(<0.05);血清LPO水平、W/D、BALF中蛋白浓度明显下降(<0.05);LA组TNF-水平呈进行性下降,在注射后各时点与LPS组比较均明显降低(<0.05)。结论 LA对LPS诱发的大鼠ALI/ARDS模型的损伤有一定保护作用。     

Systemic Inflammation and Disseminated Intravascular Coagulation in Early Stage of ALI and ARDS: Role of Neutrophil and Endothelial Activation

To determine the existence of a close link between inflammation and coagulation in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and to examine their prognostic value in the development of ARDS and clinical outcome, we made a prospective cohort study. The study subjects consisted of 57 patients: 19 patients with ARDS and 38 patients with ALI as defined by a Lung Injury Score of > or =2.5 and 1.0 to less than 2.5, respectively. According to the outcome, the patients were subdivided into the survivors and the nonsurvivors. Ten normal healthy volunteers served as control subjects. Plasma levels of soluble L-, P-, and E-selectins, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), thrombomodulin (sTM), and neutrophil elastase were measured within 24 h after the diagnosis of ALI or ARDS. The number of systemic inflammatory response syndrome (SIRS) criteria being met by the patients and the disseminated intravascular coagulation (DIC) scores were determined simultaneously. The number of SIRS criteria and the DIC scores of the patients with ALI or ARDS showed high values, and more than half of the patients were complicated by DIC. The levels of sL-selectin in both groups of the patients were significantly lower than those of the control subjects. All other soluble adhesion molecules, neutrophil elastase, and sTM in the patients with ALI and ARDS were markedly elevated than those in the control subjects. The levels sICAM-1, sVCAM-1, and sTM in the ARDS patients significantly increased compared with the ALI patients. The number of SIRS criteria and the DIC scores in the nonsurvivors showed higher values than those in the survivors. In addition, we found significant differences in the levels of soluble adhesion molecules, neutrophil elastase, and sTM between the survivors and the nonsurvivors. In conclusion, we found a concurrent activation of both inflammation and coagulation in the patients with ALI or ARDS. The results also suggest that systemic activation of inflammation and coagulation associated with endothelial injury has prognostic value for the development of ARDS and poor outcome.     

Endothelial progenitor cells: the promise of cell-based therapies for acute lung injury

Background

Endothelial progenitor cells (EPCs) are defined as a special type of stem cell that have been found to directly incorporate into injured vessels and that participate in angiogenesis and reconstruction by differentiation into endothelial cells. EPCs are widely used to therapeutically treat cardiovascular disease, limb ischemia and vascular repair. However, the role of EPCs in inflammatory diseases, especially in lung injury, is less studied.

Objective

To investigate the application of EPCs to vascular repair, and the role of EPCs in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).

Methods

A computer-based online search was performed in the PubMed database and Web of Science database for articles published, concerning EPCs, angiogenesis, ALI/ARDS and stem cell transplantation

Conclusion

EPCs have a therapeutic potential for vascular regeneration and may emerge as novel strategy for the diseases that are associated with ALI/ARDS.     

CD44 as a novel target for treatment of staphylococcal enterotoxin B-induced acute inflammatory lung injury

Exposure to bacterial superantigens, such as staphylococcal enterotoxin B (SEB), can lead to the induction of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). In the current study, we investigated the role of CD44 in ALI/ARDS. Intranasal exposure of CD44 wild-type mice to SEB led to a significant increase in the expression of CD44 on lung mononuclear cells. CD44 knockout mice developed significantly reduced SEB-induced ALI/ARDS, through reduced inflammatory cytokine production and reduced lung inflammatory cells, compared to similarly treated CD44 wild-type mice. Mechanistically, deletion of CD44 altered SEB-induced cytokine production in the lungs and reduced the ability of SEB-exposed leukocytes to bind to lung epithelial cells. Finally, treatment of SEB-exposed mice with anti-CD44 mAbs led to significant reduction in vascular permeability, reduction in cytokine production, and prevented inflammatory cell infiltration in the lungs. Together, these results suggest the possibility of targeting CD44 for the treatment of SEB-induced ALI/ARDS.     

Soluble endothelial selectin in acute lung injury complicated by severe pneumonia

Background: Pneumonia is still one of the most frequent causes of death in the elderly. Complication of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by pneumonia makes patients very ill due to severe respiratory failure. Biomarkers that can discriminate the presence of complicating ALI/ARDS are required for early detection. The aim of this research was to investigate whether soluble endothelial selectin (sES) could be a biomarker for ALI.Methods: Serum sES levels were measured in 27 pneumonia patients, who were enrolled between April 2006 and September 2007. Among these patients, six had ALI or a condition that was clinically comparable to ALI (cALI). All patients who were enrolled were successfully treated and survived.Results: Circulating sES levels were elevated in pneumonia patients with ALI/cALI, and sES levels decreased following treatment of their pneumonia. Univariate and multivariate logistic regression analyses showed that sES was the only significant factor for identifying complicating ALI/cALI, independently of C-reactive protein (CRP) and lactate dehydrogenase (LDH). By receiver operating characteristic (ROC) curve analysis, the cut-off value for sES was 40.1 ng/mL, with a sensitivity of 0.8 and a specificity of 0.8.Conclusion: sES may be a useful biomarker for discriminating complicating ALI/cALI in patients with severe pneumonia.     

Concise review: Mesenchymal stem cells for acute lung injury: role of paracrine soluble factors

Morbidity and mortality have declined only modestly in patients with clinical acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), despite extensive research into the pathophysiology. Current treatment remains primarily supportive with lung-protective ventilation and a fluid conservative strategy. Pharmacologic therapies that reduce the severity of lung injury in preclinical models have not yet been translated to effective clinical treatment options. Consequently, further research in translational therapies is needed. Cell-based therapy with mesenchymal stem cells (MSCs) is one attractive new therapeutic approach. MSCs have the capacity to secrete multiple paracrine factors that can regulate endothelial and epithelial permeability, decrease inflammation, enhance tissue repair, and inhibit bacterial growth. This review will focus on recent studies, which support the potential therapeutic use of MSCs in ALI/ARDS, with an emphasis on the role of paracrine soluble factors.     

Vascular immunotargeting of glucose oxidase to the endothelial antigens induces distinct forms of oxidant acute lung injury: targeting to thrombomodulin, but not to PECAM-1, causes pulmonary thrombosis and neutrophil transmigration

Oxidative endothelial stress, leukocyte transmigration, and pulmonary thrombosis are important pathological factors in acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Vascular immunotargeting of the H(2)O(2)-generating enzyme glucose oxidase (GOX) to the pulmonary endothelium causes an acute oxidative lung injury in mice.(1) In the present study we compared the pulmonary thrombosis and leukocyte transmigration caused by GOX targeting to the endothelial antigens platelet-endothelial cell adhesion molecule (PECAM) and thrombomodulin (TM). Both anti-PECAM and anti-TM delivered similar amounts of (125)I-GOX to the lungs and caused a dose-dependent, tissue-selective lung injury manifested within 2 to 4 hours by high lethality, vascular congestion, polymorphonuclear neutrophil (PMN) sequestration in the pulmonary vasculature, severe pulmonary edema, and tissue oxidation, yet at an equal dose, anti-TM/GOX inflicted more severe lung injury than anti-PECAM/GOX. Moreover, anti-TM/GOX-induced injury was accompanied by PMN transmigration in the alveolar space, whereas anti-PECAM/GOX-induced injury was accompanied by PMN degranulation within vascular lumen without PMN transmigration, likely because of PECAM blockage. Anti-TM/GOX caused markedly more severe pulmonary thrombosis than anti-PECAM/GOX, likely because of TM inhibition. These results indicate that blocking of specific endothelial antigens by GOX immunotargeting modulates important pathological features of the lung injury initiated by local generation of H(2)O(2) and that this approach provides specific and robust models of diverse variants of human ALI/ARDS in mice. In particular, anti-TM/GOX causes lung injury combining oxidative, prothrombotic, and inflammatory components characteristic of the complex pathological picture seen in human ALI/ARDS.