Cardioprotective role of cardiotrophin-1 gene transfer in a murine model of myocardial infarction

We observed the effect of cardiotrophin-1 (CT-1) gene transfer on cardiomyocytes in a murine model of myocardial infarction. Sixty male CD-1 mice weighing approximately 40 g were used in the study. Forty mice were subjected to left coronary artery ligation and randomized to receive AdCT-1 vector (treated group) or AdLacZ vector (control group) treatment, with 20 mice for each group. AdCT-1 or AdLacZ vector was directly injected into the border zone of the ischemic myocardium at six sites, 10 min after ligation (10 microl/site, 2.5 x 10(6) PFU/100 microl). Twenty mice undergoing thoracotomy and injection of an equal volume of phosphate-buffered saline solution but not coronary ligation served as sham group. Hemodynamics, histopathology and cardiomyocyte apoptosis were detected at 2 weeks after injection. Four animals in sham, nine in control, and six in treated groups died during the experiment. The remaining 41 mice were included in the study. Mean arterial pressure, left ventricular systolic pressure, and the maximum rate of left ventricular pressure rise or fall were significantly higher in treated group than in control group (P < 0.01 for all), whereas left ventricular end-diastolic pressure, infarct size, the ratio of right ventricle or lung weight to body weight, and apoptotic index were significantly lower in treated group than in control group (P < 0.01 for all). The caspase-3 activation and mitochondrial cytochrome c release were also lower in treated group than in control group (P < 0.01 for each). AdCT-1 injection significantly inhibited Fas, Bax and p53, and increased CT-1 and Bcl-2 expression in myocardium. Our results suggest that AdCT-1 vector can be effectively transfected and continued to express bioactive CT-1 protein in myocardium. CT-1 plays an important cardioprotective effect on myocardial damage in the murine model of myocardial infarction.     

Cardioprotective role of cardiotrophin-1 gene transfer in a murine model of myocardial infarction

We observed the effect of cardiotrophin-1 (CT-1) gene transfer on cardiomyocytes in a murine model of myocardial infarction. Sixty male CD-1 mice weighing approximately 40 g were used in the study. Forty mice were subjected to left coronary artery ligation and randomized to receive AdCT-1 vector (treated group) or AdLacZ vector (control group) treatment, with 20 mice for each group. AdCT-1 or AdLacZ vector was directly injected into the border zone of the ischemic myocardium at six sites, 10 min after ligation (10 μl/site, 2.5 × 10⁶ PFU/100 μl). Twenty mice undergoing thoracotomy and injection of an equal volume of phosphate-buffered saline solution but not coronary ligation served as sham group. Hemodynamics, histopathology and cardiomyocyte apoptosis were detected at 2 weeks after injection. Four animals in sham, nine in control, and six in treated groups died during the experiment. The remaining 41 mice were included in the study. Mean arterial pressure, left ventricular systolic pressure, and the maximum rate of left ventricular pressure rise or fall were significantly higher in treated group than in control group (P < 0.01 for all), whereas left ventricular end-diastolic pressure, infarct size, the ratio of right ventricle or lung weight to body weight, and apoptotic index were significantly lower in treated group than in control group (P < 0.01 for all). The caspase-3 activation and mitochondrial cytochrome c release were also lower in treated group than in control group (P < 0.01 for each). AdCT-1 injection significantly inhibited Fas, Bax and p53, and increased CT-1 and Bcl-2 expression in myocardium. Our results suggest that AdCT-1 vector can be effectively transfected and continued to express bioactive CT-1 protein in myocardium. CT-1 plays an important cardioprotective effect on myocardial damage in the murine model of myocardial infarction.     

The role of aquaporin-1 (AQP1) expression in a murine model of lipopolysaccharide-induced acute lung injury

A murine model of lipopolysaccharide (LPS)-induced acute lung injury (ALI) was used to evaluate whether aquaporin-1 (AQP1) is involved in lung inflammation and lung edema formation. Swiss strain mice (n = 122) had LPS (5 mg/kg) instilled intratracheally (IT), and were then treated with either 0.9 % saline or dexamethasone (5 mg/kg/day). Mice were euthanized at 2 days and 7 days after treatment. Inflammatory cytokines (TNF-alpha, IL-6), protein concentration in bronchoalveolar lavage (BAL) fluid, lung wet-to-dry weight ratio, histology, immunohistochemistry, and AQP1 Western blot were performed. Lung wet-to-dry weight ratio and lung vascular permeability were also measured in the AQP1 knockout mice (n = 9) that received IT LPS (5 mg/kg) at 2 days. Intratracheal instillation of LPS produced a severe lung injury at 2 days, characterized by elevation of TNF-alpha, IL-6 in the BAL fluid, and by histological changes consistent with increased lung vascular permeability and neutrophil infiltration. AQP1-immunoreactivity in the pulmonary capillary endothelium was reduced at 2 days and 7 days. Administration of dexamethasone improved LPS-induced ALI and retained expression of AQP1. However, depletion of AQP1 did not affect lung edema formation, lung vascular permeability, or lung histology. The results suggest that although AQP1 expression is decreased after lung injury, depletion of AQP1 does not alter lung inflammation and lung edema induced by LPS.     

Insulin promotes T cell recovery in a murine model of autoimmune myocarditis

Glucose‐insulin‐potassium (GIK) is a useful adjunct to myocarditis. Besides its essential action in energy metabolism, insulin also exerts an anti‐inflammatory effect. This study investigated the effect of insulin on myocardial inflammation in experimental autoimmune myocarditis (EAM) in mice and its potential role in T cell regulation. Mice were divided randomly into a normal control group, a saline‐treated EAM group and an insulin‐treated EAM group. The histopathological changes of myocardium, α‐myosin heavy chain (MyHCα)_614–629 antigen‐specific autoantibody titre, the serum level of cardiac troponin I (cTnI), mitogen‐activated protein kinase (MAPK) family members' activity and content were measured. Furthermore, the phenotype of T lymphocyte subsets in splenocytes was analysed to evaluate the immune status of mice. Insulin reduced serum cTnI of EAM mice on days 14 and 21 (P < 0·05) after immunization, with no changes in blood glucose and autoantibody production. Western blot revealed that extracellular signal‐regulated protein kinase (ERK1/2) may be a determining factor in this process. Total ERK1/2 and phospho‐ERK1/2 (p‐ERK1/2) were both up‐regulated in insulin‐treated mice after immunization. We also found that insulin treatment promoted T cell recovery without changing the naive‐to‐memory T‐cell ratio; in particular, CD3⁺ T cells in insulin‐treated mice proliferated more vigorously than in control mice (P < 0·05). We report here for the first time that insulin alleviates myocarditis in the EAM model. These data show that insulin has a direct effect on T cell proliferation in EAM. It is possible that GIK or insulin may assist T cell recovery towards normal in myocarditis, especially for diabetic or hyperglycaemic patients.     

早期生长反应基因-１在急性胰腺炎大鼠肝组织的表达

目的： 观察早期生长反应基因-１(Egr-1)在大鼠不同程度急性胰腺炎（AP）及AP发病后不同时间在肝组织的表达，并研究EGR-1与AP肝脏损害的关系。方法: 先将24只雄性Wistar大鼠随机均分为4组，即A、B、C、D 4组，分别于胆总管内逆行注入生理盐水或不同浓度牛磺胆酸钠溶液，3 h后处死动物，留取血清、肝脏及胰腺组织。另将30只雄性Wistar大鼠随机均分为５组，即E、F、G、H、I组，5%牛磺胆酸钠溶液（0.75 mL/kg）胆管内逆行注射，分别于注射后1 h、3 h、6 h、12 h、24 h处死动物同上留取标本。检测血清AST、LDH、TNF-α、IL-1β水平，对胰腺组织病理评分，并对肝组织进行EGR-1免疫组化染色。结果: (1)通过注射不同浓度牛磺胆酸钠溶液，成功地复制出不同严重程度的AP动物模型，A、B、C、D 4组动物胰腺病理评分、炎性细胞因子水平、AST及LDH水平均随着牛磺胆酸钠浓度的升高而逐渐上升；(2)肝组织EGR-1免疫组化染色显示，在不同程度AP组，EGR-1表达量随AP病情加重而逐渐增加，并与反映AP病情各指标如肝实质酶、炎性细胞因子浓度、胰腺病理评分均呈显著正相关，且表达部位也有所不同。EGR-1在AP发病后不同时间肝组织的表达，具有极明显的细胞种类与部位的差异。在观察时间内，以发病后3 h表达量最高。结论: EGR-1可能与AP时伴发的肝脏损害严重程度有关，其机制可能与其介导的炎性细胞因子生成有关。     

Decreased surfactant protein-B expression and surfactant dysfunction in a murine model of acute lung injury

This study examines the relationships between inflammation, surfactant protein (SP) expression, surfactant function, and lung physiology in a murine model of acute lung injury (ALI). 129/J mice received aerosolized endotoxin lipopolysaccharide [LPS] daily for up to 96 h to simulate the cytokine release and acute inflammation of ALI. Lung elastance (E(L)) and resistance, lavage fluid cell counts, cytokine levels, phospholipid and protein content, and surfactant function were measured. Lavage and lung tissue SP content were determined by Western blot and immunohistochemistry, and tissue messenger RNA (mRNA) levels were assessed by Northern blot and in situ hybridization. Tumor necrosis factor-alpha and neutrophil counts in bronchoalveolar lavage fluid increased within 2 h of LPS exposure, followed by increases in total protein, interleukin (IL)-1beta, IL-6, and interferon-gamma. E(L) increased within 24 h of LPS exposure and remained abnormal up to 96 h. SP-B protein and mRNA levels were decreased at 24, 48, and 96 h. By contrast, SP-A protein and mRNA levels and SP-C mRNA levels were not reduced. Surfactant dysfunction occurred coincident with changes in SP-B levels. This study demonstrates that lung dysfunction in mice with LPS-ALI corresponds closely with abnormal surfactant function and reduced SP-B expression.     

Prox1 expression patterns in the developing and adult murine brain.

Prox1, a homeobox gene related to the Drosophila gene prospero, is necessary for retina, lens, liver, pancreas, and lymphatics development. However, not much is yet known about Prox1 expression during central nervous system development. Here we provide a detailed analysis of Prox1 mRNA and protein expression during prenatal and postnatal murine brain development. Prenatally, Prox1 is expressed in the subventricular zone or in early differentiating regions of the brain. At these stages, Prox1 mRNA, but not Prox1 protein, was also detected in several regions of the prethalamus and hypothalamus. At an early postnatal stage, Prox1 expression is mainly detected in several nuclei of the thalamus, the cerebellum, and the hippocampus. In adulthood, Prox1 expression remains only in the hippocampus and cerebellum. These complex patterns of expression suggest that Prox1 activity is differentially required during brain development and adulthood.     

T-helper-cell cytokines in the early evolution of murine Lyme arthritis.

Genetic susceptibility to murine Lyme arthritis has been correlated with the dominance of T-helper (Th1)- or Th2-cell-associated cytokines. To determine when commitment of the Th cell phenotype occurs, we examined the kinetics of gamma interferon (IFN-gamma) and interleukin-4 (IL-4) production by lymph node T cells of disease-susceptible C3H/HeN and disease-resistant BALB/c mice from days 2 through 30 of infection, a period encompassing the evolution of disease and early regression. BALB/c mice produced more IFN-gamma on day 2 of infection than did C3H/HeN mice, whereas IL-4 was first detected on day 14. In contrast, only IFN-gamma could be detected in C3H/HeN mice, and the levels steadily increased from day 2 to surpass those seen in BALB/c mice by day 14 of infection. Despite the difference in cytokine profiles, both BALB/c and C3H/HeN mice developed comparable arthritis assessed at 14 days of infection. Arthritis regressed by day 30 in BALB/c mice but persisted in C3H/HeN mice. These studies are the first to demonstrate that the Th2 response to Borrelia burgdorferi infection of BALB/c mice is preceded by a Th1 cytokine response. Moreover, the timing of the appearance of IL-4 suggests that its primary effect is not in preventing disease, as suggested by others, but, rather, in hastening the resolution of inflammation. The implications of these findings for the orchestration of host defense against B. burgdorferi infection are discussed.     

Therapeutic benefits of cardiotrophin-1 gene transfer in a mouse model of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a recessive autosomal disorder characterized by degeneration of lower motor neurons caused by mutations of the survival motor neuron gene (SMN1). No curative treatment is known so far. Mutant mice carrying homozygous deletion of Smn exon 7 directed to neurons display skeletal muscle denervation, moderate loss of motor neuron cell bodies and severe axonal degeneration. These features, similar to those found in human SMA, strongly suggest the involvement of a dying back process of motor neurons and led us to test whether neurotrophic factors might have a protective role in SMA. We report here the therapeutic benefits of systemic delivery of cardiotrophin-1 (CT-1), a neurotrophic factor belonging to the IL-6 cytokine family. Intra-muscular injection of adenoviral vector expressing CT-1, even at very low dose, improves median survival, delays motor defect of mutant mice and exerts protective effect against loss of proximal motor axons and aberrant cytoskeletal organization of motor synaptic terminals. In spite of the severity of SMA phenotype in mutant mice, CT-1 is able to slow down disease progression. Neuroprotection could be regarded as valuable therapeutic approach in SMA.     

Dynamics of expression of the mRNA for cytokines and inducible nitric synthase in a murine model of the Parkinson's disease

The inflammatory reaction and oxidative stress has been linked with PD. Proinflammatory cytokines promote neurodegeneration or neuroprotection in different animal models. In addition, these cytokines have been reported to increase iNOS expression. With the RT-PCR method we evaluated mRNA levels for IL 1beta, IL6, TNF, IFNgamma, IL-10 and iNOS in the striatum of C57BL/6 mice after MPTP intoxication. The IL1beta mRNA expression rapidly increased and peaked at 6 h. The first increase of mRNA for TNFalpha and IFNgamma was noticed at 6-24 h and the second at the 7th day after MPTP intoxication. Two peaks of IL10 mRNA were seen, immediately (6 h) and at the 3 day post MPTP injection. The peak of mRNA level for IL6 was observed at the 7th day. Expression of mRNA for iNOS peaked at 24 h, started decreasing on the 3rd day, but was still present till the 14th day. Those findings suggest that cytokine network and iNOS may be involved in the development of immune changes accompanying degeneration of the nigrostriatal system.     

肿瘤坏死因子α mRNA在小鼠病毒性心肌炎中的表达及意义

目的　研究病毒性心肌炎 (VMC)小鼠肿瘤坏死因子α(TNF α)的动态变化及mRNA的表达及其在VMC小鼠发病中的意义。方法　用逆转录 聚合酶链反应 (RT PCR)方法检测小鼠VMCTNF αmRNA的表达 ,同时用酶联免疫吸附试验法 (ELISA)检测VMC小鼠在接种病毒后 3、5、7、9、15、35d血清TNF α的变化 ,并分析了TNF α与VMC发病的可能关系。结果　实验发现VMC小鼠TNF αmRNA表达量明显增加 ,而且接种病毒后 7d的表达量 (1 94 )大于 3d(1 0 9)和对照组 (0 0 7)。VMC小鼠在接种病毒后 3～ 35d各时点的血清TNF α水平 (分别为D3组 15 9 7± 4 0 8;D5组 2 12 7± 4 6 0 ;D7组 2 96 7± 34 3;D9组 2 6 7 3± 4l 4 ;D15组 187 8± 4 9 6 ;D35组 15 5 4± 35 9)均明显高于对照组 (12 7 2± 13 8,P <0 0 5或 0 0 1)。结论　小鼠VMC血清TNF α及其mRNA水平升高 ,TNF α可能参与了VMC的发病     

Monoclonal anti-idiotypic antibodies regulate the expression of virus-induced murine myocarditis.

A monoclonal anti-idiotypic antibody (anti-Id), produced by electrofusion and designated anti-Id88, was able to modulate expression of murine autoimmune myocarditis mediated by coxsackievirus B3 (CVB3). The anti-Id was characterized as an immunoglobulin G2b species possessing kappa light chains and was able to reduce expression of inflammatory myocarditis in anti-Id-pretreated mice challenged with CVB3. Anti-Id88 was able to stimulate specific cell-mediated immunity against anti-Id88, as well as CVB3, and exerted a suppressive effect on the proliferation of mixed spleen cell populations from virus-exposed mice. Anti-Id stimulated an anti-anti-Id antibody 3 population able to bind antibody 2 F(ab')2 fragments or virus antigen in an indirect enzyme-linked immunosorbent assay. Western blot (immunoblot) analysis of anti-Id88 exhibited binding of syngeneic anti-Id antibody to idiotypes present on immunoglobulin G molecules from virus-immunized mice.     

Effect of clindamycin in a model of acute murine toxoplasmosis

Objective: To characterize the antitoxoplasma activity of clindamycin in a murine model of acute toxoplasmosis.
Method: Rates of survival and mean survival times of Swiss Webster mice infected intraperitoneally with 10⁶-10² tachyzoites of the RH strain of Toxoplasma gondii treated with clindamycin or sulfamethoxazole (positive control) or untreated (negative control) were compared. Survivors were submitted to examination of untreated brain tissue preparations, intraperitoneal and peroral subinoculations of brain tissue homogenates into fresh mice, and to patho-histology, including immunohistochemistry, of brain and lungs.
Results: The effect of clindamycin treatment (400 mg/kg/day) on infected Swiss Webster mice was inoculum size dependent, ranging from no survivals in animals infected with 10⁶ parasites, to 100% survivals with an inoculum of 10². Treatment initiated 24 h before and at time of infection prolonged mean survival times comparably to sulfamethoxazole, and significantly when compared to untreated controls. In contrast, treatment initiated 48 h postinfection with an inoculum of 10⁶ did not postpone death. In the clindamycin-treated survivors, there was no biological or histologic evidence for the persistence of toxoplasma.
Conclusions: The results obtained show that at an appropriate parasite dose/drug dose ratio, clindamycin is strongly toxoplasmacidal in a murine model of acute toxoplasmosis.     

Endogenous MCP-1 influences systemic cytokine balance in a murine model of acute septic peritonitis

Sepsis and septic syndrome represent an intense systemic response with multiple physiologic and immunologic abnormalities, leading to multiple organ failure. Recent investigations suggest that the critical conditions are balanced by endogenous cytokines. In the present study, we examined the involvement of endogenous monocyte chemoattractant protein (MCP)-1 in the regulation of cytokine production in tissue/organs in a murine model of acute septic peritonitis induced by cecal ligation and puncture (CLP). Initial studies showed that CLP induced elevated levels of MCP-1 in tissues, such as liver, lung, and kidney. To neutralize endogenous MCP-1, either anti-MCP-1 antibodies or control antibodies were intraperitoneally administered 2 h prior to CLP. Administration of anti-MCP-1 antibodies resulted in a decrease in the level of interleukin (IL)-13 in tissues, while increasing the level of tumor necrosis factor-alpha, compared to control. In addition, anti-MCP-1 treatment decreased the level of IL-12 and, in contrast, increased the level of IL-10 in specific tissues. These findings suggest that endogenous MCP-1 influences the cytokine balance in tissues in favor of anti-inflammatory and immune-enhancing cytokines, probably protecting the host from tissue/organ damage during sepsis.     

CpG oligodeoxynucleotides do not require TH1 cytokines to prevent eosinophilic airway inflammation in a murine model of asthma

BACKGROUND: Oligodeoxynucleotides (ODNs) containing the dinucleotide CpG in a specific sequence context (CpG-ODNs) have the ability to prevent the development of eosinophilic airway inflammation and bronchial hyperreactivity in a murine model of asthma. We have previously demonstrated that CpG-ODNs stimulate expression of the T(H1)-inducing cytokines IFN-gamma and IL-12 in a murine model of asthma and that this stimulation is associated with the protection against asthmatic inflammation. OBJECTIVE: The purpose of this study was to examine whether the protection conferred by CpG-ODNs in a schistosome egg-egg antigen murine model of asthma is dependent on the induction of IFN-gamma, IL-12, or both. METHODS: C57BL/6 mice were sensitized to schistosome eggs in the presence or absence of CpG-ODNs or control ODNs and then stimulated with soluble egg antigen in the airway. The protection offered by CpG-ODNs in these mice was compared with the protection induced by CpG-ODNs in IL-12 and IFN-gamma knockout mice and in mice treated with anticytokine blocking antibodies. Double-knockout mice (IL-12/IFN-gamma) were also generated and used in these studies. Determinations included airway eosinophilic inflammation and bronchial hyperreactivity to inhaled methacholine. RESULTS: We found that CpG-ODNs confer protection against both airway eosinophilia and bronchial hyperreactivity in the absence of IFN-gamma or IL-12 or in the presence of both cytokines together. However, in the absence of either IL-12 or IFN-gamma, mice require 10 times as much CpG-ODNs to be protected against the induction of airway eosinophilia. The T(H2) cytokines IL-4 and IL-5 were reduced in all of the CpG-treated mice, although less in the absence of IL-12 and IFN-gamma. CONCLUSION: These data indicate that CpG-ODNs prevent the generation of T(H2)-like immune responses by multiple mechanisms, which involve, but do not require, IL-12 and IFN-gamma. A direct suppressive effect of CpG-ODNs on T(H2) responses is suggested by their reduction in IFN-gamma and IL-12 knockout mice.     

Inactivation of LGI1 expression accompanies early stage hyperplasia of prostate epithelium in the TRAMP murine model of prostate cancer

The LGI1 gene has been implicated in tumor cell invasion through regulation of the ERK pathway. To determine whether human prostate cancer cells (PC3, 22RV, Du145) are similarly affected by exposure to LGI1, we conducted scratch wound assays and demonstrated that the secreted LGI1 protein can reduce cell motility, an essential component of invasion and metastasis. These studies have now been extended to an in vivo mouse model of prostate cancer. Using a BAC transgenic mouse expressing a GFP reporter gene under the control of cis regulatory elements, we demonstrated that LGI1 is highly expressed in the normal prostate epithelium. To determine whether loss of LGI1 expression is associated with development and progression of murine prostate cancer, we bred the GFP reporter BAC transgenic mice with TRAMP mice which undergo early hyperplasia and progressive stages of prostate cancer. In the F1 animals, although the surrounding normal prostate epithelium expressed high levels of LGI1 in the double transgenic mice, the LGI1 gene had been inactivated even at the earliest stages of hyperplasia. This observation supports the suggestion that inactivation of LGI1 in certain cell types is related to tumor progression. Taken together these results suggest that LGI1 may be an important molecule for the arrest of prostate cancer cell invasion and possibly as a biomarker for early detection of prostate hyperplasia.     

Role of cytokines in autoimmune myocarditis and cardiomyopathy

Cellular as well as humoral autoimmune responses are critically associated with the pathogenesis and progression of myocarditis and cardiomyopathy. Cytokines appear to play critical roles in accentuating or regulating autoimmune mechanisms in these disorders. However, depending on the triggers of autoimmune responses against the heart, such as viral or parasitic infections and experimental immunization with cardiac myosin, the effect of each cytokine on autoimmune myocardial disease may vary. Cytokines may represent new therapeutic targets in the treatment and prevention of autoimmunity-mediated myocarditis and cardiomyopathy, though the etiology and variability in the type of autoimmune responses should be taken into account in the development of cytokine/anti-cytokine treatment of these disorders.     

Bile acids modulate colonic MAdCAM-1 expression in a murine model of combined cholestasis and colitis

Primary sclerosing cholangitis (PSC) is a progressive fibrosing cholestatic liver disease that is strongly associated with inflammatory bowel disease (IBD). PSC-associated IBD (PSC-IBD) displays a unique phenotype characterized by right-side predominant colon inflammation and increased risk of colorectal cancer compared to non-PSC-IBD. The frequent association and unique phenotype of PSC-IBD suggest distinctive underlying disease mechanisms from other chronic liver diseases or IBD alone. Multidrug resistance protein 2 knockout (Mdr2^−/−) mice develop spontaneous cholestatic liver injury and fibrosis mirroring human PSC. As a novel model of PSC-IBD, we treated Mdr2^−/− mice with dextran sulfate sodium (DSS) to chemically induce colitis (Mdr2^−/−/DSS). Mdr2^−/− mice demonstrate alterations in fecal bile acid composition and enhanced colitis susceptibility with increased colonic adhesion molecule expression, particularly mucosal addressin-cell adhesion molecule 1 (MAdCAM-1). In vitro, ursodeoxycholic acid (UDCA) co-treatment resulted in a dose dependent attenuation of TNF-α-induced endothelial MAdCAM-1 expression. In the combined Mdr2^−/−/DSS model, UDCA supplementation attenuated colitis severity and downregulated intestinal MAdCAM-1 expression. These findings suggest a potential mechanistic role for alterations in bile acid signaling in modulating MAdCAM-1 expression and colitis susceptibility in cholestasis-associated colitis. Together, our findings provide a novel model and new insight into the pathogenesis and potential treatment of PSC-IBD.     

紧密连接蛋白-1、闭锁蛋白、白细胞介素-18在急性重症心肌炎心脏粘膜中的表达

目的 观察急性重症心肌炎大鼠心脏粘膜紧密连接蛋白(ZO-1)、闭锁蛋白(occludin)及白细胞介素(IL)-18的表达变化,探讨急性重症心肌炎时心脏屏障功能损伤的机制.方法 选择SD大鼠60只,随机分为三组,分别为对照组、假手术组、心肌炎组,每组各20只.心肌炎组制作急性重症心肌炎模型,假手术组大鼠麻醉后手术进腹,仅翻动心脏组织.对照组不进行腹部手术.术后24h处死各组大鼠,取心脏组织.光镜下观察心脏组织病理学改变,免疫组化检测各组心脏粘膜ZO-1、Occludin、IL-18蛋白的表达,实时荧光定量PCR检测各组心脏粘膜ZO-1、Occludin、IL-18 mRNA的表达.结果 光镜下可见心肌炎组心脏黏膜绒毛上皮坏死脱落,血管充血扩张,大量中性粒细胞浸润.对照组、假手术组、心肌炎组ZO-1阳性率分别为85％、70％、15％,心肌炎组ZO-1阳性率低于对照组及假手术组(P＜0.05).对照组、假手术组、心肌炎组Occludin阳性率分别为75％、65％、20％,心肌炎组Occludin阳性率低于对照组及假手术组(P＜0.05).对照组、假手术组、心肌炎组IL-18阳性率分别为15％、15％、80％,心肌炎组IL-18阳性率高于对照组及假手术组(P＜0.05).心肌炎组ZO-1、Occludin mRNA表达水平均低于对照组及假手术组(P＜0.05);,IL-18高于对照组及假手术组(P＜0.05).结论 急性重症心肌炎时,紧密连接相关蛋白Z0-1、Occludin表达降低,IL-18表达增加,可能共同参与了急性心肌炎心脏粘膜屏障功能损伤的病理过程.