急性肺损伤保护作用机制研究进展

急性肺损伤(acute lung injury,ALI)是临床常见危重症,病死率极高,其发病机制极为复杂,临床上针对急性肺损伤缺乏有效的治疗药物及治疗手段。现从抗炎、抗氧化、内皮细胞保护及改善微循环等方面对急性肺损伤保护作用机制作一综述。     

间充质干细胞移植治疗急性肺损伤的研究进展

急性肺损伤是一种临床常见的危重病症,临床上传统的治疗方法一般以尽早去除诱因、控制感染、机械通气及器官功能支持治疗为主。间充质干细胞属于成体干细胞的一种,能主动归巢至肺损伤部位,并通过向肺泡和支气管上皮细胞分化参与组织修复,同时间充质干细胞能够调节急性肺损伤时局部和全身炎症反应和免疫紊乱,从而发挥治疗作用,可能是治疗急性肺损伤的一个很有前景的方法。作者就间充质干细胞移植治疗急性肺损伤的研究进展进行综述。     

L-精氨酸对实验性大鼠急性肺损伤的保护作用

目的 探讨一氧化氮(NO)前体物质L-精氨酸(L-Arg)在内毒素(LPS)致大鼠急性肺损伤中的作用.方法 SD大鼠24只随机分为空白对照组、LPS组和L-Arg(500 mg/kg)组.腹腔注射LPS(100 μg/kg)复制急性肺损伤动物模型.在LPS注射2 h后,取大鼠肺称其湿重与干重,计算肺湿干比,测定肺灌洗液蛋白含量和白细胞数量,并进行肺组织病理学检查.结果 与对照组相比,LPS组肺湿干比、肺灌洗液蛋白含量和白细胞计数显著增高(P<0.01,n=8),病理学切片见急性肺损伤性变化;与LPS组相比,L-Arg组肺湿干比、肺灌洗液蛋白含量和白细胞计数显著降低(P<0.01,n=8),肺组织急性损伤显著减轻.结论 L-Arg具有抗LPS致急性肺损伤的作用.     

氨溴索注射液对急性肺损伤患者保护作用的研究

目的 探讨氨溴索对急性肺损伤患者预后的影响,对进一步发展至急性呼吸窘迫综合征（ARDS）的作用.方法 选择77例病情程度基本相同的急性肺损伤患者作为研究对象,随机分为氨溴索治疗组38例,常规治疗组39例.比较治疗7天后两组患者动脉血气的差异;比较两组患者的预后,包括ARDS发生率、病死率、存活患者的住院时间、SIRS评分及肺损伤评分.结果 治疗7天后两组患者动脉血气分析指标均有明显改善（P〈0.01）,氨溴索治疗组比常规治疗组改善更明显（P〈0.01）;氨溴索治疗组患者ARDS发生率（28.95%）低于常规治疗组（53.85%）（P〈0.05）,氨溴索治疗组存活患者的SIRS评分（1.71±1.61）低于常规治疗组（2.73±1.41）（P〈0.05）;肺损伤评分（0.24±0.16）明显低于常规治疗组（0.79±0.21）,住院时间（14.01±7.16）天,明显短于常规治疗组（19.14±6.25）天（均P〈0.01）.结论氨溴索对急性肺损伤有保护作用,可降低急性肺损伤患者ARDS的发生率,缩短患者住院时间,改善预后.     

不同浓度hUCMSCs对重度烧伤大鼠急性肺损伤的保护作用初探

目的:通过气管内给药的方法比较不同浓度人脐带间充质干细胞气管内移植对重度烧伤致急性肺损伤大鼠的保护作用。方法:建立50%面积全层烫伤大鼠模型,将75只成熟雄性Wistar大鼠随机分为正常对照组(A组)、生理盐水组(B组)、1×10~5HUCMSCs移植组(C)、5×10~5HUCMSCs移植组(D)、1×10~6HUCMSCs移植组(E),每组15只,B组及移植组(C、D、E组)烫伤后立即液体复苏,B组烫伤后气管内滴注0.2 m L生理盐水,移植组气管内滴注不同浓度h UCMSCs,分别在移植后的天第1、3、7天留取大鼠肺组织标本,HE染色观察肺组织病理变化,MPO、CD68免疫组化染色观察肺组织中性粒细胞及肺巨噬细胞阳性表达情况。结果:肺组织病理切片可见:A组各时间点肺泡腔清晰,肺泡结构完整,偶见少量炎性细胞。烫伤后第1天,B组及移植组(C、D、E组)肺泡间隔增厚,大量红细胞漏出及炎性细胞浸润。烫伤后第3天,各组肺泡结构较前清晰,炎性细胞浸润及红细胞漏出较第一天减少,与B组相比移植组肺泡结构清晰,间隔变薄,移植组各组间改变不明显。烫伤后第7天,移植组肺组织损伤较B组明显减轻,E组损伤肺组织恢复最为明显。MPO染色显示:与A组相比,阳性细胞数在烫伤后第1天明显增加(P0.05),但各组之间无明显差异。在烫伤后第3天,与B组相比,移植组阳性细胞数减少明显(P0.05),E组阳性细胞减少明显(P0.05);在烫伤后第7天E组阳性细胞数量较其他组显著减少(P0.05)。CD68染色显示在烫伤后第1天各组阳性细胞显著增多(P0.05),在烫伤后第3天移植组阳性细胞数减少(P0.05),但各移植组间无明显差异,烫伤后第7天移植组阳性细胞数量较B组明显减少(P0.05),E组较C、D组阳性细胞减少有显著差异(P0.05)。结论:气管内移植HUCMSCs能修复重度烧伤后损伤的肺组织,减少肺组织中性粒细胞及巨噬细胞的浸润,且1×10~6HUCMSCs移植效果更明显。     

褪黑素对内毒素致大鼠急性肺损伤的保护作用

目的:研究内毒素(LPS)致大鼠急性肺损伤(ALI)时,p-p38蛋白激酶(p-p38MAPK)在肺组织的表达及褪黑素(MT)对肺组织的保护作用及其机制。方法:将72只健康雄性SD大鼠随机分为3组,每组24只,对照组(Control)、模型组(LPS)和褪黑素干预组(LPS+MT),采用气管内滴注LPS的方法建立大鼠ALI的模型,通过免疫组织化学染色和Western blot技术检测大鼠肺组织中p-p38蛋白激酶的表达变化,并在光镜下观察大鼠肺组织形态学变化。结果:Control组气道和肺组织可见反应极弱的p-p38蛋白激酶阳性细胞,散在分布于气道上皮细胞和肺泡上皮细胞;LPS组p-p38蛋白激酶阳性细胞较对照组明显增多(P0.05或P0.01),主要分布于浸润的炎症细胞、气道上皮细胞、肺泡上皮细胞和血管内皮细胞;LPS+MT组气道和肺组织中阳性细胞数较LPS组明显减少(P0.05或P0.01),Western blot结果与免疫组织化学一致。结论:LPS致大鼠急性肺损伤模型中,肺内炎性、非炎性细胞均有p38MAPK信号通路的激活;MT对急性肺损伤的保护机制可能与其抑制p38 MAPK信号通路的过度激活有关。     

一氧化碳吸入对脂多糖诱导大鼠急性肺损伤的保护作用

血红素氧合酶(heme oxygenase,HO)降解血红素的主要代谢产物一氧化碳(carbon monoxide,CO)具有抗氧化、抗炎症和抑制细胞凋亡作用,而脂多糖(lipopolysaccharide,LPS)诱导的肺组织过氧化、炎症性损伤及大量肺泡上皮和血管内皮细胞凋亡正是导致肺损伤(lung injury,LI)的关键.由此我们猜想,CO有可能通过上述机制对LI起保护作用.通过静脉注入LPS(5 mg/kg体重)诱导大鼠LI,观察吸入室内空气或2.5×10-4(V/V)CO 3 h后,肺氧化酶学、炎症细胞因子、细胞凋亡、HO-1表达及组织形态学变化.结果显示,静脉注入LPS诱导LI后,CO吸入组大鼠肺肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白细胞介素6(interlukin-6,IL-6)、丙二醛(maleic dialdehyde,MDA)、髓过氧化物酶(myeloperoxidase,MPO)和细胞凋亡分别为(0.91±0.25)pg/mg蛋白、(0.64±0.05)pg/mg蛋白、(1.02±0.23)nmol/mg蛋白、(7.18±1.62)U/mg蛋白、(1.60±0.34)%,均显著低于LI组的(1.48±0.23)pg/mg蛋白、(1.16±0.26)pg/mg蛋白、(1.27+0.33)nmol/mg蛋白、(8.16+1.49)U/mg蛋白、(3.18±0.51)%(P＜0.05).CO吸入组HO-1、白细胞介素10(interlukin-10,IL-10)表达和超氧化物歧化酶(superoxide dismutase,SOD)活性分别为(5.43±0.92)、(0.26±0.07)pg/mg蛋白、(60.09±10.21)U/mg蛋白,它们均显著高于LI组的(3.08±0.82)、(0.15±0.03)pg/mg蛋白、(50.98±6.88)U/mg蛋白(P＜0.05).与LI组相比,CO吸入组肺损伤减轻.研究结果表明,低浓度CO吸入通过抗氧化、抗炎症、抑制细胞凋亡、上调HO-1表达而减轻LPS诱导的肺损伤.     

原儿茶酸对脂多糖诱导的急性肺损伤小鼠的保护作用

目的:探索原儿茶酸(protocatechuicacid,PCA)对脂多糖(lipopolysaccharide,LPS)诱导的急性肺损伤(acute lung injury,ALI)小鼠的保护作用,探讨其保护机制。方法:将40只昆明小鼠按随机数字表法均分为空白对照组(NC组)、LPS模型组、原儿茶酸预处理组(PCA+LPS组)、地塞米松阳性对照组(Dex+LPS组),每组10只,模型组以5mg·kg-1脂多糖腹腔内注射诱导急性肺损伤。6h后处死小鼠,HE染色观察肺组织病理学变化;BCA法检测肺泡灌洗液中总蛋白浓度;ELISA检测肺泡灌洗液炎症因子TNF-α、IL-1β含量;Western Blot检测肺组织中p38MAPK、p-p38MAPK、p-ATF2蛋白的表达水平。结果:与对照组相比,模型组小鼠肺损伤明显,肺泡内出血、水肿、炎细胞浸润,肺泡灌洗液中TNF-α、IL-1β的含量及总蛋白浓度增加,肺组织中p38MAPK/p-p38MAPK、p-ATF2表达均明显增加(均P0.01)。与模型组相比,原儿茶酸预处理组、地塞米松阳性对照组肺组织病理损伤程度明显减轻,肺泡灌洗液中TNF-α、IL-1β的含量及总蛋白浓度、肺组织中p38MAPK/p-p38MAPK、p-ATF2表达均明显降低(均P0.01)。结论:PCA对LPS诱导的急性肺损伤有保护作用,其作用机制可能与其抑制p38MAPK-p-ATF2信号通路的活化、降低肺组织炎症反应有关。     

生地黄对内毒素诱导的急性肺损伤的保护作用

目的:以中医辨证论治为基础,研究生地黄对急性肺损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)的干预作用。方法:将大鼠分为对照组、模型组、生地黄预防组、生地黄治疗组,通过气管注射脂多糖(LPS)制备大鼠ALI/ARDS模型,酶联免疫法(ELISA)测定支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和白细胞介素-6(interleukin-6,IL-6)含量的变化,考马斯亮蓝法测定BALF中总蛋白含量,BALF细胞悬浮液离心涂片Giemsa染色后光镜下细胞分类计数,H.E.染色肺部组织并通过光镜观察其形态学变化,分析生地黄水提物对ALI的保护作用。结果:生地黄干预组BALF中TNF-α、IL-6含量明显降低(P0.0),蛋白含量明显降低(P0.0),中性粒细胞数(Polymorphonuclear cells,PMN)和炎症细胞总数明显降低(P0.0),肺部病理损伤减轻。结论:生地黄对ALI可能具有保护作用,对ALI/ARDS可能具有潜在的治疗价值。     

环孢菌素A对脂多糖诱导的小鼠急性肺损伤的保护作用

目的：探讨线粒体渗透性转换孔道抑制剂环孢菌素A（CsA）对脂多糖（LPS）诱导的小鼠急性肺损伤可能的保护作用。方法：LPS 4 mg/kg气管内滴入复制小鼠急性肺损伤模型,实验随机分为5组（n=24）：分别为正常对照组、LPS组、地塞米松组、CsA组和CsA＋苍术苷组。6 h后小鼠处死,测定各组支气管肺泡灌洗液乳酸脱氢酶（LDH）的含量,酶联免疫吸附法测定肺组织匀浆液TNF-α浓度,测定肺组织湿/干重比和肺毛细血管通透性指数。结果：气管内滴入LPS 6 h后,CsA组与LPS组相比,肺泡灌洗液中LDH活性降低,肺组织匀浆液TNF-α浓度下降,肺组织湿/干重比、肺毛细血管通透性指数均明显下降,但CsA＋Atr组与LPS组相比无明显区别。结论：环孢菌素A对脂多糖诱导的小鼠急性肺损伤有保护作用,其机制可能与其抑制线粒体渗透性转换孔道的开放有关。     

膝关节内干细胞/祖细胞在软骨再生中作用研究进展

关节软骨(AC)由于缺乏血管、神经和淋巴,一旦损伤无法自我修复.虽然以外源性细胞为基础的治疗策略在一定程度上能够再生关节软骨,但仍然存在手术间隔长、供体有限、细胞体外培养易去分化和病原体传播等风险.成人膝关节存在许多类型干细胞/祖细胞(SCPCs),当软骨损伤时,就会被动员,迁移到损伤部位,参与再生修复.因此,基于趋化...     

Characteristics of bone marrow-derived endothelial progenitor cells in aged mice

Evidence for dysfunction of endothelial repair in aged mice was sought by studying the pattern of induced differentiation, quantity, and function of bone marrow-derived endothelial progenitor cells (EPCs) in aged mice. The CD117-positive stem cell population was separated from bone marrow by magnetic activated cell-sorting system (MACS), and EPCs were defined by demonstrating the expression of CD117+CD34+Flk-1+ by flow cytometry. After 7 days of culture, the number of clones formed was counted, and proliferation and migration of EPCs were analyzed by MTT[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay and modified Boyden chamber assay. The results demonstrated that compared to the control group, the quantity of bone marrow-derived CD117+ stem cells and EPCs, as well as the proliferation, migration, the number of clones formed, and phagocytotic function of EPCs were significantly reduced in aged mice. There were no significant differences in the morphology and induced differentiation pattern of EPCs between the aged mouse group and the control group. Authors suggest that the dysfunction of EPCs may serve as a surrogate parameter of vascular function in old mice.     

炎症和氧化应激对内皮祖细胞动员及其功能的影响

内皮祖细胞对于维持血管内皮完整性和血管稳态具有重要作用.增强EPC的数量和功能可使心血管疾病患者获益.炎症、氧化应激对内皮祖细胞动员及其功能发挥具有重要影响,本文着重综述炎症和氧化应激对内皮祖细胞动员的调控,并探讨增进内皮祖细胞数量和功能的相关治疗策略.     

Anti-inflammatory effects of novel curcumin analogs in experimental acute lung injury

Background

Acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) have been the leading cause of morbidity and mortality in intensive care units (ICU). Currently, there is no effective pharmacological treatment for acute lung injury. Curcumin, extracted from turmeric, exhibits broad anti-inflammatory properties through down-regulating inflammatory cytokines. However, the instability of curcumin limits its clinical application.

Methods

A series of new curcumin analogs were synthesized and screened for their inhibitory effects on the production of TNF-α and IL-6 in mouse peritoneal macrophages by ELISA. The evaluation of stability and mechanism of active compounds was determined using UV-assay and Western Blot, respectively. In vivo, SD rats were pretreatment with c26 for seven days and then intratracheally injected with LPS to induce ALI. Pulmonary edema, protein concentration in BALF, injury of lung tissue, inflammatory cytokines in serum and BALF, inflammatory cell infiltration, inflammatory cytokines mRNA expression, and MAPKs phosphorylation were analyzed. We also measured the inflammatory gene expression in human pulmonary epithelial cells.

Results

In the study, we synthesized 30 curcumin analogs. The bioscreeening assay showed that most compounds inhibited LPS-induced production of TNF-α and IL-6. The active compounds, a17, a18, c9 and c26, exhibited their anti-inflammatory activity in a dose-dependent manner and exhibited greater stability than curcumin in vitro. Furthermore, the active compound c26 dose-dependently inhibited ERK phosphorylation. In vivo, LPS significantly increased protein concentration and number of inflammatory cells in BALF, pulmonary edema, pathological changes of lung tissue, inflammatory cytokines in serum and BALF, macrophage infiltration, inflammatory gene expression, and MAPKs phosphorylation . However, pretreatment with c26 attenuated the LPS induced increase through ERK pathway in vivo. Meanwhile, compound c26 reduced the LPS-induced inflammatory gene expression in human pulmonary epithelial cells.

Conclusions

These results suggest that the novel curcumin analog c26 has remarkable protective effects on LPS-induced ALI in rat. These effects may be related to its ability to suppress production of inflammatory cytokines through ERK pathway. Compound c26, with improved chemical stability and bioactivity, may have the potential to be further developed into an anti-inflammatory candidate for the prevention and treatment of ALI.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0199-1) contains supplementary material, which is available to authorized users.     

Anti-inflammatory effects of anethole in lipopolysaccharide-induced acute lung injury in mice

Aims

Anethole, the major component of the essential oil of star anise, has been reported to have antioxidant, antibacterial, antifungal, anti-inflammatory, and anesthetic properties. In this study, we investigated the anti-inflammatory effects of anethole in a mouse model of acute lung injury induced by lipopolysaccharide (LPS).

Main methods

BALB/C mice were intraperitoneally administered anethole (62.5, 125, 250, or 500 mg/kg) 1 h before intratracheal treatment with LPS (1.5 mg/kg) and sacrificed after 4 h. The anti-inflammatory effects of anethole were assessed by measuring total protein and cell levels and inflammatory mediator production and by histological evaluation and Western blot analysis.

Key findings

LPS significantly increased total protein levels; numbers of total cells, including macrophages and neutrophils; and the production of inflammatory mediators such as matrix metalloproteinase 9 (MMP-9), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nitric oxide (NO) in bronchoalveolar lavage fluid. Anethole (250 mg/kg) decreased total protein concentrations; numbers of inflammatory cells, including neutrophils and macrophages; and the inflammatory mediators MMP-9, TNF-α and NO. In addition, pretreatment with anethole decreased LPS-induced histopathological changes. The anti-inflammatory mechanism of anethole in LPS-induced acute lung injury was assessed by investigating the effects of anethole on NF-κB activation. Anethole suppressed the activation of NF-κB by blocking IκB-α degradation.

Significance

These results, showing that anethole prevents LPS-induced acute lung inflammation in mice, suggest that anethole may be therapeutically effective in inflammatory conditions in humans.     

mTOR and autophagy in regulation of acute lung injury: a review and perspective

The mammalian target of rapamycin (mTOR) is a central regulator of many major cellular processes including protein and lipid synthesis and autophagy, and is also implicated in an increasing number of pathological conditions. Emerging evidence suggests that both mTOR and autophagy are critically involved in the pathogenesis of pulmonary diseases including acute lung injury (ALI). However, the detailed mechanisms of these pathways in disease pathogenesis require further investigations. In certain cases within the same disease, the functions of mTOR and autophagy may vary from different cell types and pathogens. Here we review recent advances about the basic machinery of mTOR and autophagy, and their roles in ALI. We further discuss and propose the likelihood of cell type- and pathogen-dependent functions of these pathways in ALI pathogenesis.     

胃饥饿素对小鼠急性肺损伤的保护作用及其机制研究

目的 探讨胃饥饿素对小鼠急性肺损伤的保护作用和机制.方法 将60只小鼠采用随机数字表法分为6组:对照组、模型组、胃饥饿素低、中、高剂量组和地塞米松组.对照组和模型组腹腔注射0.2 mL生理盐水,胃饥饿素各组分别注射400、200、100 μg/kg溶液,地塞米松组注射2 mg/kg.给药后1h,对照组滴注等体积生理盐水...