腺苷酸环化酶抑制剂和激动剂在脂多糖诱导的急性肺损伤中的作用

目的探讨腺苷酸环化酶抑制剂(SQ22536)和激动剂(Forskolin)在脂多糖(LPS)诱导的急性肺损伤(acute lung injury,ALI)中的作用。方法 ICR小鼠随机分为生理盐水组(N组)、模型组(L组)、地塞米松组(D组)、SQ22536组(SQ组)和Forskolin组(F组),气道内滴入LPS制备ALI模型。6 h后观察肺组织病理改变,测定肺泡灌洗液(BALF)中白细胞、中性粒细胞和白蛋白含量,检测肺组织中髓过氧化物酶(MPO)、肿瘤坏死因子-α(TNF-α)、白介素-1β(IL~(-1)β)、白介素-6(IL-6)和c AMP含量。结果 Forskolin可明显改善肺组织病理变化,降低BALF中白细胞、中性粒细胞和蛋白含量,MPO活性和TNF-α含量明显降低,c AMP含量升高;SQ22536与M组相比差异均无显著性。结论 Forskolin对ALI的保护机制可能与升高c AMP水平、抑制中性粒细胞黏附和趋化及降低TNF-α等相关炎症因子含量有关。     

cAMP/PKA信号通路在肾上腺肿瘤中的作用

目的：探讨cAMP/PKA信号通路在肾上腺肿瘤中的作用。方法将人肾上腺肿瘤H295R细胞随机分为对照组、实验组A及实验组B,对照组不进行处理,实验组A加入cAMP衍生物db-cAMP,实验组B加入db-cAMP及cAMP/PKA信号通路抑制剂H-89,分别检测细胞PKA活性;应用Western Blot方法检测cAMP/PKA信号通路下游CREB蛋白的磷酸化水平;CCK8实验检测细胞72 h的增殖水平;糖皮质激素分泌实验检测3组H295R的激素分泌能力。结果实验组A的PKA活性水平、CREB蛋白的磷酸化水平、细胞增殖水平、糖皮质激素分泌水平均较对照组和实验组B显著升高(P<0．05);而实验组B与对照组比较差异无统计学意义(P<0．05)。结论 cAMP/PKA信号通路的异常活化能够促进肾上腺肿瘤的形成与功能的发挥。     

cAMP/Epac信号通路调控慢性咳嗽及中药干预作用研究进展

慢性咳嗽属于临床疑难杂症,气道炎症、咳嗽神经通路敏感性增强以及炎性疼痛是其主要病理学基础。环磷酸腺苷(cyclic adenosine monophosphate,cAMP)/cAMP直接激活的交换蛋白分子(exchange protein activated by cAMP,Epac)信号通路广泛参与气道炎症(特别是气道神经源性炎症)、咳嗽神经兴奋性以及炎性疼痛等生理病理过程。本文就近年来cAMP/Epac信号通路调控气道炎症、咳嗽通路增敏、炎性疼痛而影响慢性咳嗽以及中药干预作用研究进行综述,为研究慢性咳嗽以及镇咳药的开发应用提供理论基础。     

急性肺损伤发病机制的研究进展

急性肺损伤/急性呼吸窘迫综合征发病机制复杂,病死率高,是临床常见的危重症。各种肺内外因素引起多种炎性介质的释放,参与炎症的细胞和细胞因子成为研究的热点,这些细胞和细胞因子、炎症介质构成的炎症反应和免疫调节的"细胞网络"和"细胞因子网络"在其发病过程中发挥重要作用。以下将对近年来参与急性肺损伤的主要炎症细胞及炎症因子的研究进展做一综述。     

急性肺损伤发病机制的研究进展

目的急性肺损伤/急性呼吸窘迫综合征发病机制复杂,病死率高,是临床常见的危重症。各种肺内外因素引起多种炎性介质的释放,参与炎症的细胞和细胞因子成为研究的热点,这些细胞和细胞因子、炎症介质构成的炎症反应和免疫调节的"细胞网络"和"细胞因子网络"在其发病过程中发挥重要作用。以下将对近年来参与急性肺损伤的主要炎症细胞及炎症因子的研究进展做一综述。     

脂多糖诱导大鼠急性肺损伤的机制研究进展

在最近几年的治疗中发现,急性肺损伤（ALI）发病过程中,通过对大鼠肺部上皮细胞中的核因子-κB（NF-κB）因子传导通路实施阻断,能够对脂多糖诱导引发的大鼠急性肺损伤中肺部组织出现的炎症以及水肿起到减轻的效果[1、2].因此可以证明NF-κB在急性肺损伤的发病过程中具有相应的作用.并且,因为急性肺损伤属于肺部炎症,白细胞出现聚集,由于亲环素A对白细胞起到趋化作用,因此在急性肺损伤的病变过程也是具有一定作用的[3、4].     

低氧诱导因子1α在急性肺损伤发病机制中的研究进展

低氧诱导因子1a（HIF-1a)能与β亚基结合形成二聚体复合物,调节下游基因的表达参与低氧适应、机体炎症反应、免疫调节等,在急性肺损伤中发挥重要作用。本文就NF-kB/HIF-1a、ROS/HIF-1a、腺苷A2/HIF-1a途径与急性肺损伤发病机制的研究进展进行综述。     

通过环磷酸腺苷信号通路治疗焦虑症的研究进展

目的:综述近年来国内外通过第二信使环磷酸腺苷(c AMP)信号通路治疗焦虑症的相关研究进展,寻找治疗焦虑症新的潜在靶点。方法:以AnxietyCyclic adenosine monophosphateAdenylate cyclasePhosphodiesteraseProtein kinase A等组合作为关键词,查阅2000-2014年Pub Med、Science Direct、Springer等数据库,检索药物通过作用第二信使c AMP通路治疗焦虑症的研究文献,对其相关研究进展进行汇总分析。结果与结论:共检索到相关文献236篇,其中有效文献33篇。c AMP信号通路治疗抑郁症的潜在靶点可能位于腺苷酸环化酶(AC)、磷酸二酯酶(PDE)和c AMP依赖的蛋白激酶A(PKA)。通过敲除Ca2+调节的AC基因、抑制或激活相关G蛋白偶联受体、抑制AC活性、降低细胞内c AMP水平可产生一定的抗焦虑样作用;而PDE抑制剂和PKA激动药则可通过增加特定脑区内的c AMP水平产生抗焦虑样作用,但其治疗焦虑症的作用机制有待更深入的研究。     

TLR9信号通路参与急性肺损伤的作用机制研究

目的研究Toll样受体-9在急性肺损伤中的作用机制,为临床诊疗提供理论依据。方法分离40例急性肺损伤患者的外周血单个核细胞,采用RT—PCR检测Toll样受体-9mRNA表达,外周血单个核细胞（PBMC）经过非甲基化胞嘧啶-鸟嘌呤二核苷酸序列的寡脱氧核苷酸（CpGODN）和不含非甲基化胞嘧啶-鸟嘌呤二核苷酸序列的寡脱氧核苷酸（non—CpGODN）、空白培养三种形式培养72h。采用3H—TdR掺入法测定PBMC增值变化,采用流式细胞仪检测T细胞亚群比例、T细胞表面CD69分子变化及CD8＋T细胞内IFN-γ和IL-4的表达。采用ELISA法对PBMC上清液IFN-α的浓度,并评价其对氯喹和抑制性ODN的反应程度。结果急性肺损伤患者PBMC表达TLR9mRNA的表达强度为（0．75±0．08）,与健康组（0．76±0．09）比较差异无统计学意义（P〉0．05）;CpGODN诱导急性肺损伤患者PBMC增殖（P〈0．05）,增加CD3＋T细胞表面CD69分子的表达（P〈0．05）;增强CD8＋T细胞产生IFN-γ的能力（P〈0．05）;增强CD4＋T／CD8＋T比值（P〈0．05）;CpGODN可促进IFN-α的分泌（P〈0．05）;氯喹和抑制性ODN会抑制CpGODN产生IFN—α。结论TLR9参与急性肺损伤患者的免疫调节,其激活效应包括促进PMBC活化、增加PBMC中CD4＋T的比例,诱导并增殖IFN-α产生,促进CD8＋T分泌IFN-γ。     

羟乙基淀粉130/0.4对大鼠内毒素性急性肺损伤ICAM-1表达的影响及MAPK信号通路在其中的作用

目的探讨不同剂量羟乙基淀粉溶液(hydroxyethylstarch,HES)130.04对大鼠内毒素性急性肺损伤(acute lunginjury,ALI)肺组织细胞间粘附分子1(intercellular adhesionmolecule1,ICAM-1)表达的影响及丝裂原活化蛋白激酶(mi-togen activated protein kinase,MAPK)通路在其中的作用。方法36只♂SD大鼠,随机分为6组,每组6只,N组(对照组)不给予脂多糖(lipopolysaccharide,LPS),H1、H2、H3、H4组给予LPS后分别按照3.75,7.5,15,30ml.kg-1的剂量持续输入HES130/0.4,L组给予LPS后持续输入生理盐水。于LPS注射4h后处死大鼠,测定肺组织中性粒细胞髓过氧化物酶(MPO)活性、肺湿干重比(W/D)、ICAM-1蛋白和mRNA表达、MAPK激酶活性以及支气管肺泡灌洗液(BALF)中总蛋白和白细胞数。结果与N组比较,L组肺组织MPO活性、W/D比、ICAM-1蛋白和mRNA、p-ERK、p-p38、p-JNK表达以及BALF中总蛋白和白细胞数升高;与L组比较,H1和H2组肺组织和BALF中上述指标降低,其中以7.5ml.kg-1剂量最为明显。结论中小剂量使用HES130/0.4可改善内毒素性急性肺损伤炎症反应,这种作用可能与通过MAPK通路抑制ICAM-1蛋白和mRNA的表达有关。     

急性肾损伤诱导急性肺损伤的研究进展

急性肾损伤是一种ICU患者中常见的疾病,致死率较高,当合并肺损伤时,致死率显著提高,可达到80%。急性肾损伤可导致全身体液灌注量增加,血浆渗透压升高进而引起肺水肿和急性呼吸衰竭。同时,炎症反应,氧化应激,细胞凋亡和可溶性调节因子代谢异常等也可能参与急性肾损伤诱导的肺损伤。对急性肾损伤诱导肺损伤的临床认识和可能发病机制的研究,将有助于临床疾病的治疗和死亡率的降低,同时也将有助于对其它肾脏疾病发病机制的认识。     

Expression and functional role of the RhoA/Rho-kinase pathway in rat coeliac artery

1. Rho-kinase (ROK) stimulation represents a key step in the maintenance of agonist-induced contraction, an effect counteracted by nitric oxide (NO) released from the endothelium. The aim of the present study was to characterize the involvement of ROK in smooth muscle contraction of the rat coeliac artery using functional and expression studies. 2. Rings of rat coeliac artery were mounted in 5 mL myographs containing warmed and oxygenated Krebs' solution. Rings were connected to isometric transducers and data were recorded in a PowerLab system (ADInstruments, Colorado Springs, CO, USA). After a 60 min equilibration period, preparations were precontracted with phenylephrine (1 micromol/L). Endothelial integrity was assessed by treating the vessels with acetylcholine (1 micromol/L). Expression of ROKalpha, ROKbeta and RhoA was analysed using western blot, whereas Rho guanine nucleotide exchange factors (RhoGEF) were measured at the mRNA level. 3. The addition of Y-27632 (0.01-30 micromol/L) caused sustained relaxation of rings contracted with phenylephrine (PE; 1 micromol/L), with intact or denuded endothelium (pEC50 = 6.38 +/- 0.03 and 5.65 +/- 0.02, respectively). NG-Nitro-L-arginine methyl ester (100 micromol/L) or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (10 micromol/L), but not indomethacin (10 micromol/L), caused marked rightward shifts of the concentration-response curves to Y-27632. The contractile response to KCl (80 mmol/L) was significantly reduced by Y-27632, with a maximal inhibition of 57 +/- 6%. Nifedipine (0.1-100 nmol/L) fully blocked KCl-evoked contractions, but only marginally affected those in response to PE (27 +/- 2% maximal inhibition). At 1 micromol/L, Y-27632 also significantly enhanced relaxations to sodium nitroprusside (SNP; 0.0001-1 micromol/L). 4. At 1 micromol/L, SNP (but not 1 micromol/L Y-27632) significantly elevated the cGMP content above basal levels. Coincubation with SNP and Y-27632 increased cGMP levels, but the results were not significantly different from those in the presence of SNP alone. 5. Western blot analysis revealed the protein expression of RhoA, ROKalpha and ROKbeta. The PDZ-RhoGEF, p115RhoGEF and leukaemia-associated RhoGEF (LARG) mRNA expression in coeliac artery was visualized by electrophoresis on agarose gels. 6. The results clearly demonstrate a role for the RhoA/ROK signalling pathway in the regulation of rat coeliac artery smooth muscle contraction. The findings of the present study suggest that endogenous nitric oxide-induced relaxation is mediated, in part, by inhibition of RhoA/ROK signalling in this tissue.     

Functional characterization of the cAMP-binding proteins Epac in cardiac myocytes

The cyclic AMP (cAMP)-binding proteins, Epac, are guanine nucleotide exchange factors for the Ras-like small GTPases. Since their discovery in 1998 and with the development of specific Epac agonists, many data in the literature have illustrated their critical role in multiple cellular events mediated by the second messenger cAMP. Given the importance of cAMP in cardiovascular physiology and physiopathology, there is a growing interest to delineate the role of these multi-domain Epac in the cardiovascular system. This review will focus on recent pharmacological and biochemical studies aiming at understanding the role of Epac in cardiomyocyte signaling and hypertrophy     

The role of Epac proteins,novel cAMP mediators,in the regulation of immune,lung and neuronal function

Chronic degenerative inflammatory diseases, such as chronic obstructive pulmonary disease and Alzheimer''s dementia, afflict millions of people around the world, causing death and debilitation. Despite the global impact of these diseases, there have been few innovative breakthroughs into their cause, treatment or cure. As with many debilitating disorders, chronic degenerative inflammatory diseases may be associated with defective or dysfunctional responses to second messengers, such as cyclic adenosinemonophosphate (cAMP). The identification of the cAMP-activated guanine nucleotide exchange factors for Ras-like GTPases, Epac1 (also known as cAMP-GEF-I) and Epac2 (also known as cAMP-GEF-II), profoundly altered the prevailing assumptions concerning cAMP signalling, which until then had been solely associated with protein kinase A (PKA). Studies of the molecular mechanisms of Epac-related signalling have demonstrated that these novel cAMP sensors regulate many physiological processes either alone and/or in concert with PKA. These include calcium handling, cardiac and smooth muscle contraction, learning and memory, cell proliferation and differentiation, apoptosis, and inflammation. The diverse signalling properties of cAMP might be explained by spatio-temporal compartmentalization, as well as A-kinase anchoring proteins, which seem to coordinate Epac signalling networks. Future research should focus on the Epac-regulated dynamics of cAMP, and, hopefully, the development of compounds that specifically interfere with the Epac signalling system in order to determine the precise significance of Epac proteins in chronic degenerative inflammatory disorders.     

Therapeutic inhibition of CXCR2 by Reparixin attenuates acute lung injury in mice

Background and purpose:

Acute lung injury (ALI) remains a major challenge in critical care medicine. Both neutrophils and chemokines have been proposed as key components in the development of ALI. The main chemokine receptor on neutrophils is CXCR2, which regulates neutrophil recruitment and vascular permeability, but no small molecule CXCR2 inhibitor has been demonstrated to be effective in ALI or animal models of ALI. To investigate the functional relevance of the CXCR2 inhibitor Reparixin in vivo, we determined its effects in two models of ALI, induced by either lipopolysaccharide (LPS) inhalation or acid instillation.

Experimental approach:

In two ALI models in mice, we measured vascular permeability by Evans blue and evaluated neutrophil recruitment into the lung vasculature, interstitium and airspace by flow cytometry.

Key results:

Pharmacological inhibition of CXCR2 by Reparixin reduced CXCL1-induced leukocyte arrest in the microcirculation of the cremaster muscle, but did not influence arrest in response to leukotriene B₄ (LTB₄) demonstrating specificity. Reparixin (15 μg g⁻¹) reduced neutrophil recruitment in the lung by approximately 50% in a model of LPS-induced ALI. A higher dose did not provide additional reduction of neutrophil recruitment. This dose also reduced accumulation of neutrophils in the interstitial compartment and vascular permeability in LPS-induced ALI. Furthermore, both prophylactic and therapeutic application of Reparixin improved gas exchange, and reduced neutrophil recruitment and vascular permeability in a clinically relevant model of acid-induced ALI.

Conclusions and implications:

Reparixin, a non-competitive allosteric CXCR2 inhibitor attenuates ALI by reducing neutrophil recruitment and vascular permeability.     

前列腺素E1对急性肺损伤患者的作用

目的观察前列腺素E1对ALI患者的疗效.方法ICU收治的ALI患者46例,随机分为对照组和治疗组,在常规治疗的基础上,治疗组加用前列腺素E1,观测两组患者治疗前、治疗后72h的血气分析指标并分别计算氧合指数,比较1周后的有效率.结果前列腺E1能明显提高ALI患者的PaO2、SaO2和氧合指数(P＜0.01).总有效率达82.6%.结论前列腺素E1能有效提高ALI患者的氧合功能,为一种治疗ALI的理想药物.     

Glutamine attenuates hyperoxia-induced acute lung injury in mice

1. Glutamine is an amino acid that is used to treat various diseases. Glutamine has been reported to have protective effects in human pulmonary epithelia-like cells exposed to hyperoxia. However, the effects of glutamine in hyperoxia-induced lung injury have not been investigated in vivo .
2. Mice treated with saline or glutamine [(750 mg/kg) intravenously] were randomly exposed to hyperoxia for 48 or 72 h. Control mice treated with saline or glutamine were exposed to room air. Cytokine levels in bronchoalveolar lavage fluid (BALF), heat shock protein (HSP) 70, the wet/dry (W/D) weight ratio, malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity and pathoglogical findings in lung tissue were evaluated to determine the effects of glutamine on acute lung injury. In addition, survival was monitored.
3. Lung expression of HSP70 was significantly enhanced in both the control (room air) and 48 and 72 h hyperoxic glutamine-treated mice. The W/D ratio, BALF concentrations of tumour necrosis factor-α and interleukin-6, MDA levels, MPO activity, neutrophil infiltration and interstitial oedema in lung tissue were significantly lower at 48 and 72 h of hyperoxia in glutamine-treated mice compared with saline-treated mice.
4. In a separate series of experiments evaluating survival, after 96 h continuous exposure to hyperoxia, all saline-treated mice died. In contrast, all glutamine-treated mice died after 108 h exposure to hyperoxia.
5. The data suggest that glutamine administered to mice during hyperoxia has a protective effect against hyperoxia-induced acute lung injury and improves survival.     

热休克蛋白70在大鼠急性肺损伤中的表达

目的:探讨急性肺损伤(ALI)大鼠肺组织热休克蛋白70(HSP70)的表达。方法:雌性Wistar大鼠36只,随机分为两组:急性肺损伤组(A组)、对照组(B组),大鼠尾静脉注射脂多糖(LPS)复制ALI模型。所有的动物于注射LPS后2,4,6 h处死,测定肺组织HSP70的表达、超氧化物歧化酶(SOD)活性及丙二醛(MDA)的含量。结果:A组同B组相比,各时间点肺组织HSP70表达均增多,以2,6 h升高明显(P<0.01),MDA含量增高(P<0.05),SOD活性明显降低(P<0.05)。结论:HSP70在ALI后的表达增多可能与其参与LPS所致肺损伤后的组织保护有关。     

Maresin 1 mitigates LPS-induced acute lung injury in mice

BACKGROUND AND PURPOSE

Acute lung injury (ALI) is a severe illness with a high rate of mortality. Maresin 1 (MaR1) was recently reported to regulate inflammatory responses. We used a LPS-induced ALI model to determine whether MaR1 can mitigate lung injury.

EXPERIMENTAL APPROACH

Male BALB/c mice were injected, intratracheally, with either LPS (3 mg·kg⁻¹) or normal saline (1.5 mL·kg⁻¹). After this, normal saline, a low dose of MaR1 (0.1 ng per mouse) or a high dose of MaR1 (1 ng per mouse) was given i.v. Lung injury was evaluated by detecting arterial blood gas, pathohistological examination, pulmonary oedema, inflammatory cell infiltration, inflammatory cytokines in the bronchoalveolar lavage fluid and neutrophil–platelet interactions.

KEY RESULTS

The high dose of MaR1 significantly inhibited LPS-induced ALI by restoring oxygenation, attenuating pulmonary oedema and mitigating pathohistological changes. A combination of elisa and immunohistochemistry showed that high-dose MaR1 attenuated LPS-induced increases in pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), chemokines [keratinocyte chemokine, monocyte chemoattractant protein-5, macrophage inflammatory protein (MIP)-1α and MIP-1γ], pulmonary myeloperoxidase activity and neutrophil infiltration in the lung tissues. Consistent with these observations, flow cytometry and Western blotting indicated that MaR1 down-regulated LPS-induced neutrophil adhesions and suppressed the expression of intercellular adhesion molecule (ICAM)-1, P-selection and CD24.

CONCLUSIONS AND IMPLICATIONS

High-dose MaR1 mitigated LPS-induced lung injury in mice by inhibiting neutrophil adhesions and decreasing the levels of pro-inflammatory cytokines.