醒脑静注射液对内毒素诱导大鼠肺泡巨噬细胞核转录因子-κB激活和细胞因子产生的影响

目的 探讨内毒素诱导大鼠肺泡巨噬细胞（AMs）核转录因子-κB（NF—κB）的激活和细胞因子的释放以及醒脑静注射液（XNJ）的干预作用。方法 通过支气管肺泡灌洗获取大鼠AMs。先用XNJ（10ml／L）孵育AMs2h后，加入内毒素（10μg／L）分别刺激2、4和6h。用逆转录-聚合酶链反应（RT—PCR）检测AMs中肿瘤坏死因子-α（TNF—α）基因表达水平；用酶联免疫吸附法（ELISA）检测培养上清液中TNF—α和白细胞介素-8（IL-8）含量；蛋白质免疫印迹法（Western blotting）检测AMs中NF—κB抑制蛋白-α（κB-a）、磷酸化κB-α（IκB—α）和NF—κB的水平变化。结果内毒素能增加AMs中TNF—κ基因表达水平和培养上清液中TNF—α、IL-8的水平，同时能促进IκB—α降解和NF—κB激活。与内毒素组比较，XNJ能减少AMs中TNF—α基因表达水平和培养上清液中TNF—α和IL-8的水平；抑制内毒素诱导的IκB-α降解和NF—κB激活（P均〈0．05）。结论 XNJ通过抑制AMs中IκB-α的降解，减少了NF—κB的激活，减少了内毒素诱导大鼠AMs细胞因子的产生。     

Nicorandil attenuates NF-kappaB activation, adhesion molecule expression, and cytokine production in patients with coronary artery bypass surgery

Nicorandil (NCR), a KATP channel opener, has been reported to preserve microvascular integrity in patients with reperfused myocardial infarction. We tested the hypothesis that NCR suppresses myocardial ischemia and reperfusion injury via the attenuation of cytokine production. Forty patients who underwent coronary artery bypass graft surgery were studied. The patients were randomly divided into two groups, i.e., the patients with NCR (4-6 mg/h; N group, n = 20) or without NCR (C group, n = 20). Cardiac surgery was performed under anesthesia using fentanyl and propofol. Blood were sampled at the time of induction of anesthesia, pre-cardiopulmonary bypass, 60 min after aortic occlusion, and 60, 120, and 180 min after declamping the aorta. The activation of NF-kappaB, expression of adhesion molecules, and cytokine production were evaluated in blood samples from the control volunteers by flow cytometric analysis with or without lipopolysaccharide (LPS) stimulation in vitro. Serum IL-6 and IL-8 levels in both groups increased 60 min after declamping the aorta compared with the preoperative value (P < 0.001); the increases of these parameters in N group were lower than those in C group (P < 0.05). Serum creatine kinase with muscle and brain subunits and troponin-T levels increased 60 min after declamping the aorta in two groups (P < 0,001), but the increases of both parameters in N group were lower than those in C group (P < 0.05). NF-kappaB activation, CD11b/CD18 expression, and the production of TNF-alpha, IL-8, and IL-6 in monocytes and granulocytes were inhibited by NCR in vitro. NCR suppressed the increase of inflammatory cytokines such as IL-6 and IL-8 levels, and reduced myocardial reperfusion injury. The inhibition on NF-kappaB activation, adhesion molecule expression, and cytokine production may be one of the important mechanisms of myocardial protection of NCR.     

P38 MAPK mediates myocardial proinflammatory cytokine production and endotoxin-induced contractile suppression

Cardiac myocytes are capable of synthesizing tumor necrosis factor alpha (TNF-alpha), interleukin-1, and interleukin-6 (IL-1 and IL-6). p38 mitogen-activated protein kinase (MAPK) has been implicated in oxidant-stress-induced myocardial TNF-alpha production; however, the extent to which this kinase contributes to endotoxin-induced contractile dysfunction, as well as TNF-alpha, IL-1alpha, IL-1beta, and IL-6 production, in a bloodless model of endotoxin-induced myocardial dysfunction is unknown. Isolated rat hearts were perfused (Langendorff), and myocardial contractile function continuously recorded, during direct antegrade endotoxin infusion, with and without prior p38 MAPK inhibition. Ventricular p38 MAPK activation (phospho-p38 MAPK Western), cytokine mRNA (RT-PCR), and protein (ELISA) were determined. Endotoxin resulted in progressive decline in left ventricular developed pressure and coronary flow that was attenuated with prior p38 MAPK inhibition (SB 203580). p38 MAPK inhibition significantly decreased endotoxin-induced cardiac TNF-alpha, IL-1alpha, IL-1beta, and IL-6 mRNA levels. To determine the relative effect of TNF-alpha in inducing IL-1alpha, IL-1beta, and IL-6 production, TNF-alpha was sequestered during endotoxin infusion, and TNF-alpha, IL-1beta, and IL-6 protein levels were measured. Interestingly, TNF-alpha sequestration alone significantly decreased myocardial IL-1beta and IL-6 production. We conclude that p38 MAPK is involved in endotoxin-induced myocardial contractile dysfunction and myocardial TNF-alpha production; however, p38 MAPK's involvement in IL-1 and IL-6 production may be indirectly mediated by TNF-alpha.     

Luteolin inhibits an endotoxin-stimulated phosphorylation cascade and proinflammatory cytokine production in macrophages

Flavonoids are naturally occurring polyphenolic compounds with a wide distribution throughout the plant kingdom. In the present study, we compared the ability of several flavonoids to modulate the production of proinflammatory molecules from lipopolysaccharide (LPS)-stimulated macrophages and investigated their mechanism(s) of action. Pretreatment of RAW 264.7 with luteolin, luteolin-7-glucoside, quercetin, and the isoflavonoid genistein inhibited both the LPS-stimulated TNF-alpha and interleukin-6 release, whereas eriodictyol and hesperetin only inhibited TNF-alpha release. From the compounds tested luteolin and quercetin were the most potent in inhibiting cytokine production with an IC(50) of less than 1 and 5 microM for TNF-alpha release, respectively. To determine the mechanisms by which flavonoids inhibit LPS signaling, we used luteolin and determined its ability to interfere with total protein tyrosine phosphorylation as well as Akt phosphorylation and nuclear factor-kappaB activation. Pretreatment of the cells with luteolin attenuated LPS-induced tyrosine phosphorylation of many discrete proteins. Moreover, luteolin inhibited LPS-induced phosphorylation of Akt. Treatment of macrophages with LPS resulted in increased IkappaB-alpha phosphorylation and reduced the levels of IkappaB-alpha. Pretreatment of cells with luteolin abolished the effects of LPS on IkappaB-alpha. To determine the functional relevance of the phosphorylation events observed with IkappaB-alpha, macrophages were transfected either with a control vector or a vector coding for the luciferase reporter gene under the control of kappaB cis-acting elements. Incubation of transfected RAW 264.7 cells with LPS increased luciferase activity in a luteolin-sensitive manner. We conclude that luteolin inhibits protein tyrosine phosphorylation, nuclear factor-kappaB-mediated gene expression and proinflammatory cytokine production in murine macrophages.     

山莨菪碱对急性肺损伤时肺泡巨噬细胞分泌细胞因子的干预探讨

目的观察山莨菪碱(654-2)对急性肺损伤(ALI)大鼠肺泡巨噬细胞(AM)分泌肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)的影响,探讨其对ALI治疗作用的可能机制。方法复制ALI大鼠模型。实验动物随机分为ALI模型组、654-2治疗组、对照组,进行各组大鼠动脉血气、肺湿／干(W／D）值测定及肺组织病理学光镜检查。分离培养各组大鼠肺泡巨噬细胞,采用生物活性法进行AM上清液TNF-α、IL-6测定。结果654-2治疗组大鼠AM分泌TNF-α［（38．98±4.51)KU/L］和IL-6［（20．82±6.3)kU/L］的水平明显低于ALI组［TNF-α为(68.27±9.13)kU/L,P＜0.001;IL-6为(33.84±9.02)kU/L,P＜0.01］,并能使血气改善(P＜0.05)、W／D值下降(P＜0.05),肺组织损伤程度减轻。结论654-2对ALI大鼠肺泡巨噬细胞过度活化、分泌TNF-α、IL-6具有显著抑制作用,在一定程度上防止ALI的发生和发展。     

Erythromycin modulates eosinophil chemotactic cytokine production by human lung fibroblasts in vitro

Recent studies suggest that erythromycin can suppress the production of some cytokines and may be an effective treatment for asthma. Eosinophil chemotactic cytokines have been suggested to contribute to the pathogenesis of asthma by the recruitment of eosinophils. We hypothesized that erythromycin modulates eosinophil chemotactic cytokine production. To test the hypothesis, we evaluated the potential of erythromycin to modulate the release of eosinophil chemoattractants from the human lung fibroblast cell line HFL-1. HFL-1 released eotaxin, granulocyte-macrophage colony-stimulating factor, and regulated and normal T-cell expressed and presumably secreted (RANTES) in response to interleukin-1beta or tumor necrosis factor alpha. Erythromycin attenuated the release of these cytokines and eosinophil chemotactic activity by the HFL-1. The suppressive effect on eotaxin was the most marked of these cytokines. Erythromycin therapy also suppressed eotaxin mRNA significantly. These results suggest a mechanism that may account for the apparent beneficial action of macrolide antibiotics in the treatment of allergic airway disorders.     

High frequency oscillatory ventilation attenuates the activation of alveolar macrophages and neutrophils in lung injury

BACKGROUND: Recent investigations have shown that leukocyte activation is involved in the pathogenesis of ventilator-associated lung injury. This study was designed to investigate whether the inflammatory responses and deterioration of oxygenation in ventilator-associated lung injury are attenuated by high-frequency oscillatory ventilation (HFO). We analyzed the effects of HFO compared with conventional mechanical ventilation (CMV) on the activation of pulmonary macrophages and neutrophils in 10 female rabbits. RESULTS: After surfactant depletion, the rabbits were ventilated by CMV or HFO at the same mean airway pressure. Surfactant-depletion followed by 4 h mechanical ventilation hindered pulmonary oxygenation in both groups. Impairment of oxygenation was less severe in the HFO group than in the CMV group. In the HFO group the infiltration of granulocytes into alveolar spaces occurred more readily than in the CMV group. Compared with CMV, HFO resulted in greater attenuation of beta2-integrin expression, not only on granulocytes, but also on macrophages. CONCLUSIONS: In the surfactant-depleted lung, the activation of leukocytes was attenuated by HFO. Reduced inflammatory response correlated with decreased impairment of oxygenation. HFO may reduce lung injury via the attenuation of pulmonary inflammation.     

Co-infection of macrophages modulates interferon gamma and tumor necrosis factor-induced activation against intracellular pathogens

Co-infection of macrophages (M phi) with Toxoplasma gondii and Mycobacterium avium-intracellulare complex (MAC) has been observed in patients with acquired immunodeficiency syndrome (AIDS). In this study we have demonstrated that co-infected murine M phi respond differently to cytokine stimulation than M phi infected with either of the microorganisms alone. Whereas treatment with interferon gamma (IFN-gamma) activated both single and co-infected groups of M phi to kill T. gondii, treatment with TNF did not influence the rate of MAC growth in co-infected M phi, in contrast with the inhibition of growth observed in MAC-infected M phi. These results suggest that in AIDS patients suffering infection with multiple intracellular pathogens, the ability of cytokines to stimulate microbicidal or static activity in mononuclear phagocytes can be impaired by the presence of more than one of the intracellular organisms.     

Hck tyrosine kinase activity modulates tumor necrosis factor production by murine macrophages

The hematopoietic cell kinase (hck) is a member of the src family of tyrosine kinases, and is primarily expressed in myeloid cells. Hck expression increases with terminal differentiation in both monocyte/macrophages and granulocytes and is further augmented during macrophage activation. Recent evidence has implicated src-related tyrosine kinases in critical signaling pathways in other hematopoietic lineages. Herein we demonstrate that manipulation of the level of hck expression in the murine macrophage cell line BAC1.2F5 alters the responsiveness of these cells to activation by bacterial lipopolysaccharide (LPS) but does not affect survival or proliferation. Overexpression of an activated mutant of hck in BAC1.2F5 cells augments tumor necrosis factor (TNF) production in response to LPS, whereas inhibition of endogenous hck expression, by antisense oligonucleotides, interferes with LPS-mediated TNF synthesis. Together, these observations suggest that hck is an important component of the signal transduction pathways in activated macrophages.     

Effects of extracellular pH on tumour necrosis factor-alpha production by resident alveolar macrophages

Aging reduces cardiac baroreflex sensitivity. Our primary aim in the present study was to assess the effects of aging on cardiac baroreflex sensitivity, as determined by power spectral analysis (alpha index), in a large population of healthy subjects. We also compared the alpha indexes determined by power spectral analysis with cardiac baroreflex sensitivity measured by the phenylephrine method (BS(phen)). We studied 142 subjects (79 males/63 females; age range 9-94 years), who were subdivided into five groups according to percentiles of age (25, 50, 75 and 95). Power spectral analysis yields three alpha indexes: an alpha low-frequency (LF) index of cardiac baroreflex sensitivity that ranges around 0.1 Hz; an alpha high-frequency (HF) index reflecting cardiac baroreflex sensitivity corresponding to the respiratory rate; and alpha total frequency (alpha TF), a new index whose spectral window includes all power in the range 0.03-0.42 Hz. Spectra were recorded during controlled and uncontrolled respiration. Under both conditions, all three alpha indexes were higher in the youngest age group (< or =34 years old) than in the three oldest groups. Notably, alpha TF was significantly higher in younger subjects than in the three oldest groups [14+/-1 ms/mmHg compared with 9+/-1 (P<0.05), 8.1+/-1 (P<0.001) and 8.1+/-1 (P<0.05) ms/mmHg respectively]. BS(phen) showed a similar pattern [12+/-1 ms/mmHg compared with 8+/-0.5 (P<0.001), 6+/-0.5 (P<0.05) and 6+/-1 (P<0.05) ms/mmHg respectively]. No significant differences were found for cardiac baroreflex sensitivity among the three oldest groups. All alpha indexes were correlated inversely with age. The index yielding the closest correlation with BS(phen) was alpha TF (r=0.81, P<0.001). Cardiac baroreflex sensitivity in normotensive individuals declines with age. It falls predominantly in middle age (from approx. 48 years onwards) and remains substantially unchanged thereafter. The elderly subjects we selected for this study probably had greater resistance to cardiovascular disease that is manifested clinically, with preserved cardiac baroreceptor sensitivity.     

Complement activation and cytokine production as consequences of immunological bioincompatibility of extracorporeal circuits

The use of devices which result in exposure of blood to artificial surface has gained increasing importance in routine medical and surgical practice. In the field of biocompatibility, attention has long been directed at the mechanisms of thrombus formation of surfaces. In recent years however, a special interest has emerged for the study of the immunological consequences of blood-artificial surface interactions, thus broadening the concept of hemocompatibility. The contact of blood with artificial devices results in the activation of a number of humoral and cellular processes involved in natural and in specific immunological recognition of foreign surfaces by the host, and in the secondary occurrence of acute and chronic adverse reactions in patients undergoing extracorporeal circulation. The purpose of this review is to discuss the mechanisms involved in immunological bioincompatibility of extracorporeal circuits, with particular emphasis on the molecular basis of the activation of the complement system, the role of endotoxins, and the induction of cytokine production by activated monocytes.     

Ultrasonic effects on alveolar macrophages in suspension

Rabbit alveolar macrophages in suspension were exposed to 5 or 10 min of continuous 2-MHz ultrasound with 5, 10, and 15 W/cm² spatial average intensities. Viability as determined by dye exclusion decreased with increasing intensity. Pressure experiments indicated that this was a result of acoustic cavitation. Ultrasound induced clumping of cells and often reduced membrane ruffling. Some cells were disintegrated. Cells that appeared to be otherwise intact had swollen mitochondria with ruptured cristae.     

蜂胶对慢性阻塞性肺疾病患者肺泡巨噬细胞胞浆游离钙浓度及其生成细胞因子的影响

目的:观察蜂胶对慢性阻塞性肺疾病患者(chronicobstructivepulmonarydisease,COPD)肺泡肺泡巨噬细胞(alveolarmacrophage,AM)游离钙浓度及其生成的白细胞介素8(IL-8)、一氧化氮的影响。方法:采用支气管肺泡灌洗、细胞培养和荧光指示剂方法,测定AM内钙浓度其生成的IL-8和NO。结果:COPD组患者AM内钙浓度犤(68.26±7.24)nmol/L犦,IL-8犤(29.11±9.78)ng/L犦,一氧化氮犤(27.61±8.64)μg/L犦均高于对照组犤(60.61±6.26)nmol/L,(15.42±6.78)ng/L,(13.99±7.40)μg/L犦(t=11.38～36.42,P<0.01)。脂多糖刺激以后,胞内游离钙浓度、IL-8和一氧化氮均较刺激前增高(t=12.65～32.58,P<0.01)。先加蜂胶孵育AM再加入脂多糖,胞浆内游离钙浓度、IL-8和一氧化氮较仅加脂多糖时减少(t=14.72～25.02,P<0.01)。结论:蜂胶可抑制脂多糖引起的犤Ca2+犦i增加,对脂多糖刺激的IL-8和一氧化氮升高也有抑制作用;可调节AM激活,抑制IL-8、一氧化氮分泌。     

肺泡上皮细胞功能特性与内毒素性急性肺损伤

大量的研究表明，内毒素(LPS)是存在于革兰阴性细菌细胞壁外膜中以脂多糖为主的成分。LPS可以引起急性肺损伤(acute lung injury，ALI)／急性呼吸窘迫综合征(acute respiratory distress syndrome，ARDS)，其病理变化为肺泡上皮细胞的弥散性损害，肺泡表面活性物质(pulmonary surfactant，PS)减少，大量多形核白细胞(polymorphonuclear leukocyte，PMN)聚集于肺循环，造成肺脏实质细胞损伤和肺间隙水肿，肺泡上皮细胞和血管内皮细胞受损导致大量PMN和蛋白渗漏到肺泡腔内，支气管肺泡灌洗液(bronchoalveolar lavage fluid，BALF)中蛋白含量和PMN显著升高。