The protective effect of N-acetylcysteine on apoptotic lung injury in cecal ligation and puncture-induced sepsis model

Apoptotic loss of parenchymal cells may lead to organ dysfunctions in critically ill patients with septic states. As an antioxidant, the protective effects of N-acetylcysteine (NAC) are documented in many experimental and clinical studies. In this experimental study, we investigated the role of chronically used NAC in septic lung injury on a cecal ligation and puncture (CLP) model. To evaluate this, 30 male Wistar rats were randomly divided into four groups as sham (n = 7), CLP (n = 8), sham + NAC (n = 7) and CLP + NAC (n = 8) groups. NAC was administered 150 mg kg(-1) day through intramuscular route beginning 6 h after the operations and lasting for a period of 1 week. One week later, histopathology and epithelial apoptosis were assessed by hematoxylin-eosin and immunohistochemically by M30 and caspase 3 staining to demonstrate septic lung injury. Additionally, lung tissue myeloperoxidase (MPO) activity, malondialdehyde (MDA), and nitrite/nitrate levels were measured. The MPO activity and MDA levels in lung homogenates were found to be increased in CLP group and the administration of NAC prevented their increase significantly (P < 0.05). However, there were no significant differences among the groups regarding nitrite/nitrate levels. The number of apoptotic cells was significantly lower in CLP+NAC group than CLP group, and this finding was supported by M30 and caspase 3 expression in lung (P < 0.05). Lung histopathology was also protected by NAC in CLP-induced sepsis. In conclusion, the chronic use of NAC inhibited MPO activity and lipid peroxidation, which resulted in reduction of apoptosis in lung in this CLP model. Because lung tissue nitrite/nitrate levels did not change significantly, organs other than the lungs may be responsible for producing the increased nitric oxide during sepsis. The chronic use of NAC needs further investigation for its possible antiapoptotic potential in septic states besides its documented antioxidant and antiinflammatory effects.     

Role of IFN-gamma in bacterial containment in a model of intra-abdominal sepsis.

Interferon-gamma (IFN-gamma) is a specific activator of macrophage function and plays a critical role in the host immune defense to bacterial infection. In this study we examined the role of IFN-gamma in the regulation of bacterial load in the cecal ligation and puncture (CLP) model of intra-abdominal sepsis in the rat. In initial studies, levels of IL-12, MCP-1, and IFN-gamma were measured in the peritoneal lavage fluid 24 and 48 h after CLP. IL-12 and MCP-1 levels were both significantly increased at 24 h after CLP compared to sham controls and this difference was maintained at 48 h after CLP. Interestingly, IFN-gamma levels were not significantly increased 24 h after CLP, but were increased at 48 h after CLP. These results clearly suggest that although an inflammatory response had occurred 24 h post-surgery, with increases in the proinflammatory cytokine IL-12 and the potent chemotactic agent MCP-1, levels of IFN-gamma in CLP rats were similar to sham controls. To further investigate the role of IFN-gamma on the development of sepsis we examined the effect(s) of administering anti-IFN-gamma antibody on bacterial load after CLP. We show that use of anti-IFN-gamma antibody can significantly decrease bacterial load in the peritoneum. The mechanism of the effect(s) of anti-IFN-gamma is probably by increasing intestinal adhesions to seal the cecum and reduce bacterial movement into the peritoneum.     

Resistance to acute septic peritonitis in poly(ADP-ribose) polymerase-1-deficient mice

Sepsis is associated with a widespread production of proinflammatory cytokines and various oxidant species. Activation of the enzyme poly(ADP-ribose) polymerase (PARP) has been shown to contribute to cell necrosis and organ failure in various diseases associated with inflammation and reperfusion injury. The aim of the current study was to elucidate the role of PARP activation in the multiple organ dysfunction complicating sepsis in a murine model of polymicrobial sepsis induced by cecal ligation and puncture (CLP). Mice genetically deficient in PARP (PARP-/-) and their wild-type littermates (PARP+/+) were subjected to CLP. After 12 and 24 h, the proinflammatory cytokines TNF-alpha and IL-6, as well as the anti-inflammatory cytokine IL-10, and nitrite/nitrate were measured in plasma samples. Organs were harvested for the measurement of myeloperoxidase (MPO) and malondialdehyde (MDA) levels, and immunohistochemical staining for nitrotyrosine and poly(ADP ribose) was performed in gut sections. PARP-/- mice, and their wild-type littermate showed a similar time-dependent increase in plasma nitrite/nitrate and in gut and lung MDA content, as well as the presence of nitrotyrosine in the gut. In contrast to wild-type mice showing a PARP activation in the gut, PARP-/- mice had no staining for poly(ADP ribose). PARP-/- mice had significantly lower plasma levels of TNF-alpha, IL-6, and IL-10, and they exhibited a reduced degree of organ inflammation, indicated by decreased MPO activity in the gut and lung. These effects were associated with a significant improvement in the survival of CLP in PARP-/- mice. Thus, PARP activation has an important role in systemic inflammation and organ damage in the present model of polymicrobial septic shock.     

Cecal ligation and double puncture impairs heat shock protein 70 (HSP-70) expression in the lungs of rats

Induction of the heat shock response may improve outcome from pathophysiological disturbances. This improvement is associated with and believed to result from expression of heat shock protein (HSP)-70. Therefore, we examined the temporal expression of HSP-70 in an animal model of acute respiratory distress syndrome (ARDS) secondary to fecal peritonitis. Specifically, we hypothesize that sepsis in rats impairs pulmonary HSP-70 expression. ARDS was induced in adolescent rats via cecal ligation and double puncture (2CLP). Sham-operated animals served as controls. Lung tissue was collected 0, 3, 6, 16, 24, and 48 h after 2CLP and sham operation. Northern blot hybridization analysis was performed to detect steady-state HSP-70 messenger ribonucleic (mRNA) levels. HSP-70 protein levels were determined via immunoblotting and immunohistochemistry. Mortality after 2CLP was 50% at 24 h and 75% at 48 h. Northern blot hybridization analysis revealed no significant change in steady-state HSP-70 mRNA levels in lung at any time after 2CLP. HSP-70 steady-state mRNA levels increased after sham operation and was higher than values in 2CLP at 6, 16, and 24 h. HSP-70 protein levels did not change over time in either group. Thus, the expression of HSP-70 does not change after 2CLP. Although lack of an increase in protein levels may be adaptive after sham operation, it is not appropriate after 2CLP. Therefore, failed HSP-70 expression represents a form of pulmonary epithelial dysfunction that may contribute to lung injury in sepsis.     

持续静脉泵注利多卡因对脓毒症大鼠急性肺损伤及炎症反应的影响

目的探讨利多卡因对脓毒症大鼠肺损伤及炎症因子表达的影响。 方法采用随机数字表法将60只雄性成年Sprague Dawley大鼠分为假手术组、盲肠结扎穿孔（CLP）组、利多卡因组和乌司他丁组,每组各15只。假手术组大鼠打开腹腔后缝合,其他各组采用CLP法制备脓毒症模型。利多卡因组大鼠在给予10 mg/kg的负荷剂量后,以10 mg·kg^-1·h^-1的剂量通过尾静脉持续泵注利多卡因3h;乌司他丁组大鼠进行CLP的同时,以100 000 U·kg^-1·h^-1的剂量通过尾静脉持续泵注乌司他丁3 h;假手术组和CLP组用等量等渗NaCl溶液代替。于CLP后24 h处死大鼠,采用酶联免疫吸附实验（ELISA）法测定血清中肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）及高迁移率族蛋白B1（HMGB1）表达水平;实时荧光定量PCR检测肺组织HMGB1 mRNA表达水平;苏木素-伊红（HE）染色法观察各组大鼠肺组织病理变化。另取40只大鼠（每组10只）用于观察4组大鼠72 h死亡情况。 结果4组大鼠血清中TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平比较,差异均有统计学意义（F = 189.886、237.952、175.999、179.491,P均< 0.001）。进一步两两比较发现,与假手术组比较,CLP组、利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著升高（P均< 0.05）;与CLP组比较,利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著降低（P均< 0.05）;与利多卡因组比较,乌司他丁组IL-6表达水平显著升高（P < 0.05）。HE染色结果显示,假手术组大鼠肺泡大小均匀、结构完整,肺泡上皮细胞形态正常;CLP组大鼠肺泡间隔增厚、间质充血水肿、炎症细胞浸润、肺泡塌陷;而利多卡因组和乌司他丁组病理学改变较CLP组均明显减轻,肺组织轻度水肿,肺泡及肺间质出现少量炎症。四组大鼠死亡构成比（0 /10、9/1、4/6、3/7）比较,差异有统计学意义（χ²=17.500,P < 0.001）。CLP组、利多卡因组和乌司他丁组大鼠死亡构成比均较假手术组显著升高（P均<0.008）;利多卡因组和乌司他丁组大鼠死亡构成比均较CLP组显著降低（P均<0.008）;而利多卡因组和乌司他丁组大鼠死亡构成比比较,差异无统计学意义（P > 0.008）。 结论持续静脉泵注利多卡因可以有效降低脓毒症大鼠炎症因子TNF-α、IL-6及HMGB1的表达,抑制肺组织中HMGB1 mRNA表达量,减轻脓毒症对肺组织的损伤,有效提高动物存活率,其减轻脓毒症炎症反应及肺保护作用疗效与乌司他丁相似。     

Beta-glucan attenuates inflammatory cytokine release and prevents acute lung injury in an experimental model of sepsis

Sepsis is one of the most important risk factors in acute respiratory distress syndrome (ARDS). beta-Glucan is a potent reticuloendothelial modulating agent, the immunobiological activity of which is mediated in part by an increase in the number and function of macrophages. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced lung injury. Sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. The control group received saline, and the treatment groups received beta-glucan or beta-glucan + beta-1,3-D-glucanase. Five hours thereafter, plasma tumor necrosis factor (TNF) alpha, interleukin (IL) 1beta, and IL-6 levels were determined. Presence of lung injury was determined via lung tissue myeloperoxidase (MPO) activity, intercellular adhesion molecule (ICAM) 1 levels, and histopathological examination at 18 h after CLP. In a separate set of experiments, survival was monitored for 7 days after CLP. beta-Glucan treatment led to a significant increase in survival rate (63% in glucan-treated rats vs 38% in saline-treated rats). Administration of the beta-glucan inhibitor abrogated beta-glucan's survival benefit (50%). After CLP, plasma TNF-alpha, IL-1beta, and IL-6 concentrations were increased in control animals. When beta-glucan was administered, it completely blocked the elevation of TNF-alpha, IL-1beta, and IL-6. Administration of beta-1,3-D-glucanase suppressed glucan-induced decrease in cytokines. Animals treated with beta-glucan showed a significant reduction in lung injury score, a marked decrease in ICAM-1 expression, and a significant decrease in MPO levels. In contrast, beta-1,3-D-glucanase caused a significantly increased MPO and ICAM-1 levels in the lung. These data reveal that beta-glucan treatment improved the course of CLP-induced peritonitis and attenuated the lung injury. Administration of beta-glucanase inhibited the beta-glucan activity and resulted in enhanced lung injury.     

Lipoxin a4 increases survival by decreasing systemic inflammation and bacterial load in sepsis

Sepsis is characterized by systemic inflammation with release of a large amount of inflammatory mediators. If sustained, this inflammatory response can lead to multiple organ failure and/or immunoparalysis. In the latter condition, the host may be susceptible to opportunistic infections or be unable to clear existing infections. Therefore, it is potentially beneficial to resolve inflammation by reducing inflammation without compromising host defense. We examined the effect of lipoxin A4 (LXA4), a compound with inflammatory resolution properties, in the cecal ligation and puncture (CLP) model of sepsis. Cecal ligation and puncture rats were given either saline or LXA4 (40 μg/kg, i.p.) 5 h after surgery. Lipoxin A4 administration increased 8-day survival of CLP rats, which lived longer than 48 h, and attenuated tissue injury after 8 days. Therefore, we investigated the effects of LXA4 on systemic inflammation and bacterial load 48 h after CLP sepsis. Plasma IL-6, monocyte chemotactic protein 1, and IL-10 levels were reduced in LXA4-treated rats compared with CLP rats given saline vehicle. Lipoxin A4 reduced phosphorylation of the p65 subunit of nuclear factor κB (NF-κB) at serines 536 and 468 in peritoneal macrophages, suggesting that LXA4 reduced production of proinflammatory mediators through an NF-κB-mediated mechanism. Lipoxin A4 reduced blood bacterial load and increased peritoneal macrophage number without affecting phagocytic ability, suggesting that LXA4 reduced blood bacterial load by enhancing macrophage recruitment. It also suggests that LXA4 reduced systemic inflammation and NF-κB activation without compromising host defense. Increased macrophage recruitment was in part due to a direct effect of LXA4 as LXA4 increased peritoneal macrophage recruitment in sham controls and partly due to reduced production of IL-10 as LXA4 decreased macrophage IL-10 release (a known inhibitor of macrophage migration) after CLP. The results suggest that LXA4 increased survival in sepsis by simultaneously reducing systemic inflammation as well as bacterial spread.     

Sequential changes in in vivo muscle and liver protein synthesis and plasma and tissue glutamine levels in sepsis in the rat

We have investigated sequential changes in skeletal muscle and hepatic protein synthesis following sepsis, and their relationship to changes in circulating and tissue glutamine concentrations. Male Wistar rats underwent caecal ligation and puncture (CLP) or sham operation, with starvation, and were killed 24, 72 or 96 h later. A group of non-operated animals were killed at the time of surgery. Protein synthesis was determined using a flooding dose of L-[4-(3)H] phenylalanine, and glutamine concentrations were measured by an enzymic fluorimetric assay. Protein synthesis in gastrocnemius muscle fell in all groups. Gastrocnemius total protein content was reduced after CLP and at 72 and 96 h after sham operation. After CLP, protein synthesis was lower at 24 h, and total protein content was lower at 72 and 96 h, than in sham-operated animals. CLP was associated with increased liver protein synthesis at all time points, whereas there was no change after sham operation. Liver protein content did not change after CLP, but was lower at 72 and 96 h after sham operation than in non-operated animals. Plasma glutamine concentrations were reduced at 24 h after sham operation, and at 72 and 96 h after CLP. Muscle glutamine concentrations were reduced in all groups, with the decrease being greater following CLP than after sham operation. In the liver, glutamine concentrations were unchanged after CLP, but increased after sham operation. In rats with sepsis, decreases in muscle protein synthesis and content are associated with markedly reduced muscle glutamine concentrations. Plasma glutamine concentrations are initially maintained, but fall later. In liver, protein synthesis is increased, while glutamine concentrations are preserved. These results support a peripheral-to-splanchnic glutamine flux in sepsis.     

N-acetylcysteine protects the rats against phrenic nerve dysfunction in sepsis

This study investigates the association of oxidative stress with the function of the phrenic nerve and inquires whether N-acetylcysteine (NAC) may counteract the possible detrimental effects. Thirty rats were divided into three groups: sham, cecal ligation and puncture (CLP), and CLP plus NAC treatment. Sepsis was produced by the CLP procedure. NAC was administered at 70 mg/day for 7 days. Electrophysiology was evaluated by the needle electromyography of the diaphragm and phrenic nerve conduction study. Oxidative stress was evaluated by malondialdehyde (MDA), nitrite/nitrate (NN), and reduced-glutathione (ReGSH) levels and myeloperoxidase (MPO) and catalase (CAT) activities in the phrenic nerve. In the CLP group, ReGSH and CAT were decreased (P = 0.0001, P = 0.07, respectively); and MDA, MPO, and NN were increased (P = 0.02, P = 0.0001, P = 0.043, respectively), compared with the sham group. NAC administration increased the ReGSH (P = 0.036) and decreased the MDA, MPO, and NN (P = 0.008, P = 0.01, P = 0.032, respectively), compared with the CLP group. In the CLP group, electrophysiology revealed reductions in the number of motor unit action potentials (P = 0.0001) and prolongations in the latency of the compound nerve action potential (P = 0.0001), indicating phrenic nerve neuropathy. NAC administration significantly ameliorated these electrophysiological alterations (P = 0.011, P = 0.0001, respectively), compared with the CLP group. The present results showed that intraabdominal sepsis is closely associated with phrenic nerve neuropathy. In addition, NAC administration protects the rats against the detrimental events of sepsis.     

Caffeic acid phenethyl ester reduces mortality and sepsis-induced lung injury in rats

OBJECTIVE: Sepsis and ensuing multiorgan failure continue to be the major causes of mortality in intensive care units. Nuclear factor (NF)-kappaB activation is supposed to be one of the targets in the treatment of sepsis. We studied the effectiveness of caffeic phenethyl ester (CAPE), a known NF-kappaB inhibitor, in cecal ligation and puncture (CLP)-induced sepsis and lung injury. DESIGN: Randomized, controlled animal study. SETTING: Research laboratory of an academic institution. SUBJECTS: Female Sprague-Dawley rats. INTERVENTIONS: CLP was performed in all rats except the rats in control and sham+CAPE groups. CAPE was administered to rats at the time of operation in sham+CAPE and CAPE+sepsis 0 groups. CAPE was administered to rats in the CAPE+sepsis12 group 12 hrs after CLP. Eight rats from each group were killed 24 hrs after CLP. Blood was taken for assessment of interleukin-1, interleukin-6, interleukin-10, and tumor necrosis factor-alpha; the right lung was removed for histopathologic examination and the left lung for biochemical examination. Apoptosis, inducible nitric oxide synthase, heat shock protein 70, malondialdehyde, catalase, superoxide dismutase, and glutathione peroxidase were studied. The rest of the rats were observed for mortality. MEASUREMENTS AND MAIN RESULTS: Mortality was significantly decreased in groups that received CAPE compared with the sepsis group. All cytokine levels were similar to control levels only in the CAPE+sepsis12 group. Apoptosis, inducible nitric oxide synthase, and heat shock protein 70 evaluation were significantly changed between all groups in the following order: control < sham+CAPE< CAPE+sepsis12 < CAPE+sepsis 0 < sepsis. Malondialdehyde and catalase were increased in the sepsis group. CONCLUSIONS: CAPE reduced mortality in sepsis and improved histopathologic variables best when it was administered after the onset of sepsis.     

内源性一氧化碳对感染性休克大鼠器官保护作用及机制研究

目的探讨内源性一氧化碳（CO）对感染性休克大鼠肺、肝组织的保护作用及其机制。方法采用盲肠结扎穿孔术（CLP）复制感染性休克模型，按随机数字表法将96只大鼠分为假手术对照组、CLP组、CLP＋氯血红素（Hm）组和CLP＋锌原卟啉（ZnPP）组。各组分别在制模后2、4和6h测定出入肺血中碳氧血红蛋白（COHb）水平；肺、肝组织及血液中丙二醛（MDA）含量及超氧化物歧化酶（SOD）活性；光镜下观察肺、肝组织形态学改变；免疫组化分析血红素加氧酶-1（HO-1）在肺、肝组织中的蛋白表达和分布。结果与假手术对照组比较，CLP组大鼠不同时间点的出入肺血中COHb水平以及肺、肝组织和全血中MDA含量均显著增高（P〈0．05或P〈0．01），SOD活性显著下降（P〈0．05或P〈0．01）；光镜下肺、肝组织损伤严重，HO-1蛋白表达增多。给予Hm后不同时间点，出、入肺血中的COHb水平均较CLP组进一步升高，肺、肝组织及全血中MDA含量均显著下降，SOD活性显著增高；光镜下肺、肝组织损伤明显缓解，HO-1蛋白表达进一步增多。结论感染性休克时内源性CO产生增多可能对肺、肝组织发挥了保护作用。     

Comparative study of glucocorticoids, cyclosporine A, and JTE-607 [(-)-Ethyl-N[3,5-dichloro-2-hydroxy-4-[2-(4-methylpiperazin-1-yl)ethoxy]benzoyl]-L-phenylalaninate dihydrochloride] in a mouse septic shock model

Actions of glucocorticoids, cyclosporine A, and JTE-607 [(-)-ethyl-N-[3,5-dichloro-2-hydroxy-4-[2-(4-methylpiperazin-1-yl)ethoxy]benzoyl]-L-phenylalaninate dihydrochloride], a proinflammatory cytokine inhibitor that does not inhibit interleukin (IL)-2 or interferon-gamma, were compared in a mouse septic shock model induced by cecal ligation and puncture (CLP). CLP caused elevation of macrophage inflammatory protein (MIP)-2 in lung, and MIP-2 and IL-6 in plasma and peritoneal fluid, reaching a peak 4 to 8 h after CLP. Myeloperoxidase (MPO) activity in lung increased and reached a peak 8 to 12 h after CLP. Acute treatment (subcutaneous injections 1 h before and 2 h after CLP) of mice with JTE-607 and methylprednisolone showed significant inhibition of elevated cytokine levels and MPO activity, plus increased survival rate. Similar treatment with cyclosporine A and prednisolone was ineffective. Chronic treatment (subcutaneous injection for seven consecutive days before CLP) of mice with JTE-607 also showed an inhibitory effect on cytokine production, MPO activity and mortality. In contrast, chronic treatment with cyclosporine A and prednisolone did not inhibit cytokine production or MPO activity, but rather exacerbated mortality. These results indicate that JTE-607 has protective effect on mouse mortality induced by CLP, correlating with inhibition of proinflammatory cytokines, whereas the immunosuppressants cyclosporine A and prednisolone do not. This suggests that JTE-607, a multiple cytokine inhibitor that does not cause adverse immunosuppression, is useful for treatment of septic shock.     

Interferon-gamma inhibition attenuates lethality after cecal ligation and puncture in rats: implication of high mobility group box-1

Interferon (IFN)-gamma is an important immunomodulatory agent that is stimulated during infection to aid in host defense. However, increased IFN-gamma levels have been implicated as a mediator in various models of tissue injury and endotoxemia. We have previously shown that inhibition of IFN-gamma decreased bacterial load by accelerating peritoneal fibrin deposition in the cecal ligation and puncture (CLP) model of peritonitis. In addition, circulating inflammatory mediators such as interleukin (IL)-6 were reduced by IFN-gamma inhibition. In the present study, we show that administration of IFN-gamma antibody (1.2 mg/kg, i.v.) attenuated mortality after CLP. Administration of this antibody was able to reduce mortality when given immediately after CLP or 24 h after CLP surgery. Mortality in sepsis has been closely associated with increased release of high mobility group box-1 (HMGB1). Furthermore, it has been reported that IFN-gamma stimulates the release of HMGB1 from macrophages. Our studies showed that inhibition of IFN-gamma activity in vivo reduced the levels of HMGB1 in peritoneal fluid and serum of CLP rats 24 h after surgery. In addition, the decrease in HMGB1 was associated with an increase in tissue repair as evidenced by histological analyses. These results suggest that the attenuation of mortality in IFN-gamma antibody-treated rats was associated with a decrease in HMGB1 release.     

Adenoviral transfer of HSP-70 into pulmonary epithelium ameliorates experimental acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) provokes three pathologic processes: unchecked inflammation, interstitial/alveolar protein accumulation, and destruction of pulmonary epithelial cells. The highly conserved heat shock protein HSP-70 can limit all three responses but is not appropriately expressed in the lungs after cecal ligation and double puncture (2CLP), a clinically relevant model of ARDS. We hypothesize that restoring expression of HSP-70 using adenovirus-mediated gene therapy will limit pulmonary pathology following 2CLP. We administered a vector containing the porcine HSP-70 cDNA driven by a CMV promoter (AdHSP) into the lungs of rats subjected to 2CLP or sham operation. Administration of AdHSP after either sham operation or 2CLP increased HSP-70 protein expression in lung tissue, as determined by immunohistochemistry and Western blot hybridization. Administration of AdHSP significantly attenuated interstitial and alveolar edema and protein exudation and dramatically decreased neutrophil accumulation, relative to a control adenovirus. CLP-associated mortality at 48 hours was reduced by half. Modulation of HSP-70 production reduces pathologic changes and may improve outcome in experimental ARDS.     

基于STAT3信号通路探讨艾司洛尔对脓毒症大鼠急性肝损伤的保护作用

目的探讨艾司洛尔(ES)对脓毒症大鼠急性肝损伤的保护作用及相关信号通路。方法48只雄性SPF级大鼠随机分为假手术(Sham)组、盲肠结扎穿孔(CLP+NS)组和艾司洛尔干预(CLP+ES)组(每组16只)。Sham组采用盲肠探查术,CLP+NS组、CLP+ES组采用CLP法建立脓毒症大鼠模型。CLP+ES组经颈内静脉微量泵入ES稀释液6 h,Sham组和CLP+NS组给予等质量生理盐水。术后6 h、24 h各组分别处死8只大鼠。采用HE染色,观察脓毒症大鼠肝组织形态学变化,生化分析仪检测血清肝功能指标,酶联免疫吸附法(ELISA)检测肝组织中炎性细胞因子水平,Western blot检测肝组织中STAT3信号通路标志蛋白的表达。结果CLP+NS组脓毒症大鼠肝组织炎性细胞浸润明显,而CLP+ES组炎性细胞减少,肝细胞坏死程度好转。术后6 h、24 h,CLP+NS组血清天冬氨酸转氨酶(AST)、丙氨酸转氨酶(ALT)和肝组织匀浆中高迁移率族蛋白B-1(HMGB-1)、白细胞介素-6(IL-6)均升高(P<0.05);而CLP+ES组较CLP+NS组均降低(P<0.05)。术后6 h,与CLP+NS组比较,CLP+ES组脓毒症大鼠肝组织中磷酸化信号转导和转录激活因子3(p-STAT3)表达水平明显下降(P<0.05),细胞因子信号转导抑制因子3(SOCS3)表达明显上升(P<0.05)。术后24 h,CLP+ES组上述蛋白表达与CLP+NS组比较差异无统计学意义(P>0.05)。结论艾司洛尔通过抑制STAT3信号通路,抑制炎性细胞因子释放,从而发挥对脓毒症大鼠急性肝损伤的保护作用。     

丹参酮ⅡA对脓毒症急性肺损伤小鼠多糖包被的保护作用

目的探讨丹参酮ⅡA对脓毒症急性肺损伤小鼠多糖包被的作用及机制。方法将8周龄雄性昆明小鼠随机分为3组:假手术组(S组)、脓毒症组(CLP组)及丹参酮ⅡA治疗组(TSN组)。采用盲肠结扎穿孔法建立脓毒症模型;TSN组于术后3h和12h用丹参酮ⅡA(15mg/kg,腹腔内注射)干预,S组和CLP组于同时间点给予等量生理盐水。观察CLP组及TSN组术后7d生存率。于术后24h时收集BALF及肺组织,采用ELISA法测定BALF中炎症因子及多糖包被标志物水平;HE染色观察肺部病理变化;采用比色法检测肺组织MDA含量及SOD活性。结果与S组比较,CLP组BALF中TNF-α及IL-6水平升高(P<0.01),肺损伤评分增加(P<0.01),肺组织MDA含量增加、SOD活性下降(P<0.01),肺组织syndecan-1、heparin sulfate及thrombomodulin水平明显升高(P<0.01);与CLP组比较,TSN组7d生存率升高(P<0.05),BALF中TNF-α和IL-6水平降低(P<0.05),肺损伤评分下降(P<0.05),肺组织MDA含量下降(P<0.01),SOD活性增加(P<0.05),肺组织syndecan-1、heparin sulfate及thrombomodulin水平下降(P<0.01)。结论丹参酮ⅡA可减轻肺脏多糖包被损伤,其机制可能与抑制炎症反应及氧化应激有关。     

Cyclooxygenase-2-mediated regulation of Kupffer cell interleukin-6 production following trauma-hemorrhage and subsequent sepsis

Studies indicate that trauma-hemorrhage results in activation of Kupffer cells to release inflammatory mediators and it leads to immunosuppression and increased susceptibility to subsequent sepsis. The cyclooxygenase (COX) product prostaglandin (PG) E2 appears to be central to this process, however, non-selective inhibition of COX activity with non-steroidal anti-inflammatory agents that block both the constitutive (COX-1) and inducible (COX-2) isoforms of cyclooxygenase has not yielded promising results in trauma patients. Nonetheless, it remains unknown whether selective inhibition of COX-2 activity has any salutary effect following trauma-hemorrhage and subsequent induction of sepsis. To study this, male C3H/HeN mice were subjected to laparotomy (i.e., soft-tissue trauma) and hemorrhagic shock (35 +/- 5 mmHg for 90 min, then resuscitated) or to sham operation. Twenty-four hours later, the mice were subjected to sepsis by cecal ligation and puncture (CLP) or to sham CLP. The mice were treated with the COX-2 inhibitor NS-398 (10 mg/kg body weight, intraperitoneally) or vehicle immediately after trauma-hemorrhage or sham operation, 12 h thereafter, and following CLP or sham CLP. At 5 h after CLP, plasma PGE2, Interleukin-(IL) 6, and TNF-alpha levels were determined along with Kupffer cell IL-6 and TNF-alpha production in vitro. NS-398 treatment markedly suppressed the elevation in plasma PGE2 levels following CLP. The increase in plasma IL-6 levels after CLP were also significantly attenuated by NS-398 treatment. In vitro Kupffer cell IL-6 production after CLP was significantly reduced by in vivo NS-398 treatment. However, NS-398 had no effect on TNF-alpha levels, in vivo and in vitro. These findings indicate that activation of COX-2 following trauma-hemorrhage and subsequent sepsis up-regulates Kupffer cell IL-6 production. Thus, selective inhibition of COX-2 activity may reduce the deleterious consequences of sepsis under such conditions.