亚低温减少大鼠短暂性全脑缺血后皮质iNOS诱导的神经元凋亡

为研究亚低温对大鼠脑缺血再灌注后皮质iNOS表达、NO产生及神经元凋亡的影响及探讨亚低温的神经保护机制,用大鼠短暂全脑缺血模型,采用Nissl染色观察存活神经元、免疫组化法检测iNOS、硝酸还原酶法检测NOx-水平和TUNEL染色结合电子显微镜观察检测凋亡神经元。结果显示:常温缺血组额叶皮质iNOS表达、NOx-水平增高,出现凋亡神经元;低温缺血组iNOS表达、NOx-水平明显低于常温缺血组,未检测到凋亡神经元。上述结果提示,脑缺血后iNOS来源的NO参与了神经元的凋亡过程,亚低温可减少大鼠短暂性全脑缺血后iNOS诱导的神经元凋亡。     

PCT、CRP动力学评估脓毒血症预后及诊断意义的研究

目的 观察血清降钙素原(PCT)、C反应蛋白(CRP)及其动力学变化,评估其在严重脓毒症/感染性休克患者的诊断及预后价值.方法 本研究采用回顾性分析方法,2014年9月1日至2016年4月30日选择184例ICU中被诊断为严重脓毒症/感染性休克疾病患者,检测入院时血清PCT、CRP水平和治疗后第2,第3和第5天的PCT、CRP水平.结果 通过△PCT、△CRP评估PCT、CRP的动力学在存活者与死亡组中有显著性统计学意(△PCT2/0,P=0.0001;△PCT3/0,P=0.0001;△PCT5/0,P=0.0001;△CRP2/0,P=0.0069;△CRP3/0,P=0.0001;△CRP5/0,P=0.0001),在严重脓毒症和感染性休克组中也存在显著差异(PCT5,P=0.007;△PCT5/0,P=0.007).受试者工作特征曲线(ROC)模型显示,△PCT3/0(AUC=0.721)、△PCT5/0(AUC=0.77)、△CRP5/0(AUC=0.766)水平判断严重脓毒症/感染性休克患者预后有较好的临床意义.△PCT5/0 (0.619)对严重脓毒症或感染性休克有一定的辅助诊断效果,其在ROC曲线上灵敏度、特异性均较高的临界点为0.624,所以,以第5天的血清△PCT5/0水平＞0.624可作为预测感染性休克的临界点.结论 血清中PCT、CRP对严重脓毒症/感染性休克早期有较好的临床诊断及预后价值,其动力学研究可以提高对严重脓毒症/感染性休克诊断及预后评估的敏感性及准确性.     

Apoptosis and expression of inducible nitric oxide synthase are mutually exclusive in renal mesangial cells.

Nitric oxide (NO) is a multipurpose messenger molecule, important for blood vessel relaxation, neuronal communication, and antimicrobial activities. The generation of NO from L-arginine is catalyzed by NO synthase (NOS). An inducible form of NOS, iNOS, was first characterized in macrophages and then in many other tissues and cells, including renal mesangial cells. Mesangial cells play a crucial role in the regulation of the glomerular filtration rate as well as in the pathophysiology of certain forms of glomerulonephritis in which mesangial cells and macrophages produce NO in high amounts. Because reports have associated NO production with apoptotic cell death in macrophages and we recently demonstrated NO-mediated apoptosis in mesangial cells, we searched for the relationship between in situ iNOS induction and apoptosis by iNOS immunocytochemistry and terminal desoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining. RAW 264.7 macrophages exhibited homogeneous iNOS expression and apoptotic nuclei in the iNOS-containing cells upon stimulation with interferon-gamma and lipopolysaccharide. In contrast, stimulated rat mesangial cells stained heterogeneously for iNOS, depending on cell passage and iNOS-stimulating pathway. Mesangial cells expressing iNOS did not display signs of apoptosis and, vice versa, cells showing characteristic features of apoptosis did not stain for iNOS. Thus, our study suggests that mesangial cells react to stimulation by interleukin-1 and/or cAMP-elevating compounds with mutually exclusive responses, either by expression of iNOS or by undergoing programmed cell death.     

The microRNA miR-181c controls microglia-mediated neuronal apoptosis by suppressing tumor necrosis factor

ABSTRACT: BACKGROUND: Post-ischemic microglial activation may contribute to neuronal damage through the release of large amounts of pro-inflammatory cytokines and neurotoxic factors. The involvement of microRNAs (miRNAs) in the pathogenesis of disorders related to the brain and central nervous system has been previously studied, but it remains unknown whether the production of pro-inflammatory cytokines is regulated by miRNAs. METHODS: BV-2 and primary rat microglial cells were activated by exposure to oxygen-glucose deprivation (OGD). Global cerebral ischemia was induced using the four-vessel occlusion (4-VO) model in rats. Induction of pro-inflammatory and neurotoxic factors, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and nitric oxide (NO), were assessed by ELISA, immunofluorescence, and the Griess assay, respectively. The miRNA expression profiles of OGD-activated BV-2 cells were subsequently compared with the profiles of resting cells in a miRNA microarray. BV-2 and primary rat microglial cells were transfected with miR-181c to evaluate its effects on TNF-alpha production after OGD. In addition, a luciferase reporter assay was conducted to confirm whether TNF-alpha is a direct target of miR-181c. RESULTS: OGD induced BV-2 microglial activation in vitro, as indicated by the overproduction of TNF-alpha, IL-1beta, and NO. Global cerebral ischemia/reperfusion injury induced microglial activation and the release of pro-inflammatory cytokines in the hippocampus. OGD also downregulated miR-181c expression and upregulated TNF-alpha expression. Overproduction of TNF-alpha after OGD-induced microglial activation provoked neuronal apoptosis, whereas the ectopic expression of miR-181c partially protected neurons from cell death caused by OGD-activated microglia. RNAinterference-mediated knockdown of TNF-alpha phenocopied the effect of miR-181c-mediated neuronal protection, whereas overexpression of TNF-alpha blocked the miR-181c-dependent suppression of apoptosis. Further studies showed that miR-181c could directly target the 3[prime]-untranslated region of TNF-alpha mRNA, suppressing its mRNA and protein expression. CONCLUSIONS: Our data suggest a potential role for miR-181c in the regulation of TNF-alpha expression after ischemia/hypoxia and microglia-mediated neuronal injury.     

败血症休克大鼠血管L-精氨酸/一氧化氮途径的变化

目的:观察败血症休克大鼠主动脉内膜、中膜和外膜一氧化氮合成途径的改变。方法:雄性Wistar大鼠盲肠结扎并穿孔复制败血症休克模型,分别测定假手术组、早期休克组和晚期休克组大鼠主动脉内膜、中膜和外膜的亚硝酸盐(NO^-₂)含量、一氧化氮合酶(NOS)活性及L-精氨酸(L-Arg)转运;免疫组化染色检测诱导型一氧化氮合酶(iNOS)在主动脉各层的分布。结果:早期及晚期败血症休克大鼠主动脉内膜产生的NO^-₂含量、NOS活性及L-Arg转运速率均低于假手术组,而中膜和外膜的NO^-₂、NOS活性及L-Arg转运速率则显著高于假手术组,外膜增加的程度尤为显著。免疫组织化学染色显示,败血症休克时血管中膜和外膜尤其是外膜iNOS阳性染色明显较强。结论:败血症休克时血管内膜NO合成受到抑制,而中膜和外膜NO合成显著增强,这一改变与休克状态下血管中L-Arg转运、iNOS表达及其活性的变化有关。     

Protective role of hematopoietic prostaglandin D synthase in transient focal cerebral ischemia in mice

Cerebral ischemia/reperfusion injury is characterized by the development of inflammatory response, in which vascular macrophages and endogenous microglia are involved. Recent studies showed marked induction of hematopoietic prostaglandin D synthase (HPGDS) after ischemic/reperfusion injury and its localization in microglia, but the molecular mechanism(s) of HPGDS actions in cerebral ischemia is not clear. To clarify the role of HPGDS in cerebral ischemia, C57BL/6 mice and bone marrow chimera mice with cerebral ischemia/reperfusion injury were treated with (4-benzhydryloxy-(1) {3-(1H-tetrazol-5-yl)-propyl}piperidine (HQL-79), a specific inhibitor of HPGDS. The bone marrow chimera mice exhibit expression of enhanced green fluorescent protein (EGFP) in bone marrow/blood-derived monocytes/macrophages. Mice were subjected to ischemia/reperfusion and either treated with HQL-79 (n=44) or vehicle (n=44). Brain sections prepared at 72 h and 7 days after reperfusion were analyzed for neuronal nuclei (NeuN), HPGDS, ionized calcium-binding adapter molecule 1 (Iba1), inducible NO synthase (iNOS), nitrotyrosine, nuclear factor kappa B (NF-kB) and cyclooxygenase-2 (COX-2). The mortality rate (80%) and infarct size were larger in HQL-79- than vehicle-treated mice (58.7±8.5 versus 45.2±4.9 mm³; mean±SEM, P<0.0001) at 7 days after reperfusion. HQL-79 reduced NeuN expression in the transition area and Iba1 expression (P<0.0001) in the ischemic peri- and penumbra area, but increased COX-2 (P<0.05) and NF-kB expression (P<0.05) in ischemic penumbra and increased formation of nitrotyrosine (P<0.0001) and iNOS (P<0.0001) in the ischemic core area at 72 h and 7 days after reperfusion. In EGFP chimera mice, HQL-79 increased the migration of Iba1/EGFP-positive bone marrow-derived monocytes/macrophages, and simultaneously upregulated iNOS expression in the ischemic core area (P<0.0001), but increased intrinsic microglia/macrophages in ischemic peri-area and penumbra (P<0.0001) at 72 h and 7 days after reperfusion, suggesting involvement of monocytes/macrophages in HQL-79-induced expansion of ischemic injury. Our results demonstrated that the neuroprotective effects of HPGDS in our model are mediated by suppression of activation and infiltration of inflammatory cells.     

Effects of fibronectin and group B streptococci on tumour necrosis factor-alpha production by human culture-derived macrophages.

Group B streptococci (GBS) are an important cause of sepsis and shock in the new-born. We have previously reported that GBS induce the production of tumour necrosis factor-alpha (TNF-alpha) by human monocytes and culture-derived macrophages. We have also shown that fibronectin (FN) promotes interaction between GBS and human phagocytes. In the present study, we investigated the effect of FN and GBS on the production of TNF-alpha by adult and neonatal culture-derived macrophages. We report that soluble FN alone was a strong stimulus for the production of TNF-alpha by culture-derived macrophages (FN 50 micrograms/ml = 623.33 +/- 47 pg/ml TNF, versus media alone 3 +/- 1.5 pg/ml; P < 0.0001). While GBS also induce the production of TNF-alpha by macrophages, the addition of FN to GBS had more than an additive effect on TNF-alpha levels. FN-mediated TNF-alpha production by macrophages was inhibited by both soluble arginine-glycine-aspartic acid (RGD) peptide (71%; P < 0.0001) and anti-beta 3-integrin monoclonal antibody 7G2 (54%; P < 0.0001). Neonatal culture-derived macrophages produced significantly more TNF-alpha in response to GBS (356.4 pg/ml +/- 27.7) than adult cells did (222.0 pg/ml +/- 21.0; P = 0.037), and dramatically more in response to FN alone (neonatal 1931.0 pg/ml +/- 23.0 versus adult 463.5 43.5 pg/ml; P < 0.0001). FN may contribute to the high levels of TNF-alpha production implicated in the pathophysiology of GBS sepsis and shock.     

右冠状动脉急性缺血/再灌注时窦房结细胞凋亡与iNOS蛋白的表达

目的 观察在体兔右冠状动脉急性缺血/再灌注(L/R)时窦房结细胞凋亡与诱导型一氧化氮合酶(iNOS)蛋白表达的关系。方法 在体兔右冠状动脉根部结扎或放松制作窦房结缺血/再灌注模型,健康成年新西兰兔70只分7组:假手术对照组、I2h组、I2hR2h组、I2h+NS(生理盐水)组、I2h+SMT(iNOS抑制剂Smethylisothiourea,SMT)组、I2hR2h+NS组和I2hR2h+SMT组。采用末端标记TUNEL法、SP免疫组化法结合彩色图像分析技术,检测窦房结细胞凋亡指数(AI)及iNOS蛋白表达的积分光密度(A)值。结果 ①I2hR2h组AI及iNOS A值明显高于12h组(P<0.01);②应用iNOS抑制剂后,I2h+SMT组、I2hR2h+SMT组AI及iNOS A值均明显低于I2h组和I2hR2h。组(P<0.05或P<0.01)。结论 缺血诱导窦房结细胞凋亡,再灌注加重细胞凋亡和增加iNOS表达,且细胞凋亡指数与iNOS表达变化相一致。提示iNOS生成增多可能与缺血再灌注窦房结细胞凋亡密切相关。     

SHR和WKY大鼠心肌细胞凋亡、HSP70、iNOS水平的比较研究

目的:检测自发性高血压大鼠(SHR)和正常血压大鼠(WKY)心肌细胞凋亡和诱导型一氧化氮合成酶、热休克蛋白70水平变化,并探讨其机制。方法:透射电镜、TUNEL法检测SHR和WKY大鼠心肌细胞凋亡;免疫组化检测其iNOS、HSP70蛋白表达。结果:透射电镜示SHR组可见凋亡特征的心肌细胞;TUNEL法示SHR组凋亡明显高于WKY组(P<0.01);免疫组化示SHR组iNOS、HSP70蛋白表达明显高于WKY组(P<0.01)。结论:SHR心肌细胞凋亡在自发性高血压病发病过程中起重要作用;SHR的iNOS、HSP70蛋白表达增加与细胞凋亡同时存在,可能也参与自发性高血压心肌细胞凋亡的调控。     

Effects and Mechanism of Action of Inducible Nitric Oxide Synthase on Apoptosis in a Rat Model of Cerebral Ischemia‐Reperfusion Injury

Inducible nitric oxide synthase (iNOS) is a key enzyme in regulating nitric oxide (NO) synthesis under stress, and NO has varying ability to regulate apoptosis. The aim of this study was to investigate the effects and possible mechanism of action of iNOS on neuronal apoptosis in a rat model of cerebral focal ischemia and reperfusion injury in rats treated with S‐methylisothiourea sulfate (SMT), a high‐selective inhibitor of iNOS. Seventy‐two male Sprague‐Dawley (SD) rats were randomly divided into three groups: the sham, middle cerebral artery occlusion (MCAO) + vehicle, and MCAO + SMT groups. Neurobehavioral deficits, infarct zone size, and cortical neuron morphology were evaluated through the modified Garcia scores, 2,3,5‐triphenyltetrazolium chloride (TTC), and Nissl staining, respectively. Brain tissues and serum samples were collected at 72 hr post‐reperfusion for immunohistochemical analysis, Western blotting, Terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin Nick End Labeling assay (TUNEL) staining, and enzyme assays. The study found that inhibition of iNOS significantly attenuated the severity of the pathological changes observed as a result of ischemia‐reperfusion injury: SMT reduced NO content as well as total nitric oxide synthase (tNOS) and iNOS activities in both ischemic cerebral hemisphere and serum, improved neurobehavioral scores, reduced mortality, reduced the infarct volume ratio, attenuated morphological changes in cortical neurons, decreased the rate of apoptosis (TUNEL and caspase‐3‐positive), and increased phospho (p)‐AKT expression in ischemic penumbra. These results suggested that inhibition of iNOS might reduce the severity of ischemia‐reperfusion injury by inhibiting neuronal apoptosis via maintaining p‐AKT activity. Anat Rec, 299:246–255, 2016. © 2015 Wiley Periodicals, Inc.     

Inducible nitric oxide synthase expression in human colorectal cancer: correlation with tumor angiogenesis

To investigate the potential involvement of the nitric oxide (NO) pathway in colorectal carcinogenesis, we correlated the expression and the activity of inducible nitric oxide synthase (iNOS) with the degree of tumor angiogenesis in human colorectal cancer. Tumor samples and adjacent normal mucosa were obtained from 46 surgical specimens. Immunohistochemical expression of iNOS, vascular endothelial growth factor (VEGF), and CD31 was analyzed on paraffin-embedded tissue sections. iNOS activity and cyclic GMP levels were assessed by specific biochemical assays. iNOS protein expression was determined by Western blot analysis. iNOS and VEGF mRNA levels were evaluated using Northern blot analysis. Both iNOS and VEGF expressions correlated significantly with intratumor microvessel density (r(s) = 0.31, P = 0.02 and r(s) = 0.67, P < 0.0001, respectively). A significant correlation was also found between iNOS and VEGF expression (P = 0.001). iNOS activity and cyclic GMP production were significantly higher in the cancer specimens than in the normal mucosa (P < 0.0001 and P < 0.0001, respectively), as well as in metastatic tumors than in nonmetastatic ones (P = 0.002 and P = 0.04, respectively). Western and Northern blot analyses confirmed the up-regulation of the iNOS protein and gene in the tumor specimens as compared with normal mucosa. NO seems to play a role in colorectal cancer growth by promoting tumor angiogenesis.     

Induction of inducible nitric oxide synthase is an essential part of tumor necrosis factor-alpha-induced apoptosis in MCF-7 and other epithelial tumor cells

TNF-alpha-induced cytotoxicity is mediated by the intracellular "death domain" of the 55-kDa TNF-alpha receptor and has been demonstrated to be coupled with induction of inducible nitric oxide synthase (iNOS), leading to generation of nitric oxide radicals (NO*). Because it is still widely unknown, to what extent NO* participates in the execution of TNF-alpha-induced apoptosis, NO* production, iNOS expression, and enzyme activity in relation to TNF-alpha-induced apoptotic cell death were investigated in the human breast cancer cell line MCF-7 and various other malignant cell lines. Incubation with TNF-alpha led to induction of iNOS mRNA and protein as well as enhancement of NOS activity. Augmented synthesis of NO2, the stable end product of NO* generation, was significantly correlated with augmented rates of cell death. Measurement of TNF-alpha-triggered production of reactive oxygen species (ROS) suggested a major role for NO* within the generated oxygen radicals. Dying cells showed characteristic features of apoptosis. Addition of cycloheximide (CX) enhanced apoptotic cell death by increasing iNOS activity. L-Nitro-arginine-methylester (L-NAME), a competitive NOS-inhibitor, and iNOS antisense oligonucleotides effectively prevented NO2 generation and apoptosis. Evaluation of iNOS expression during TNF-alpha-induced cell death in various malignant cell lines demonstrated iNOS positivity for all TNF-alpha-sensitive cells. The only primarily resistant line was iNOS negative. In a resistant variant of MCF-7, iNOS mRNA was still detectable; however, treatment with TNF-alpha did not enhance NOS activity. TNF-alpha sensitivity and NO2 production were completely restored by the addition of CX. Taken together, iNOS induction plays an essential role in TNF-alpha-induced apoptosis of the investigated cell lines. Further studies are necessary to define the impact of NO* in relation to other specific effectors of apoptosis such as the caspases.     

豚鼠耳蜗缺血再灌注损伤后iNOS活性与细胞凋亡关系

目的：探讨椎基底动脉缺血再灌注耳蜗组织损伤方式及可能的损伤机制。方法：健康豚鼠72只，随机分成正常组、假手术组、模型组，每组各8只。用组织化学方法观察缺血再灌注不同时间耳蜗各部位的组织改变；用免疫组织化学法（ABC）检测各组动物耳蜗中诱导型一氧化氮合酶的表达和变化；用原位凋亡法（TUNEL法）观察耳蜗的细胞凋亡情况。结果：缺血再灌注的内外毛细胞变形缺损、血管纹变薄等；诱导型一氧化氮合酶在缺血及再灌注的表达增强；正常组及假手术组没有或仅有个别部位出现细胞凋亡，缺血及再灌注各组内外毛细胞及螺旋神经节部位凋亡细胞明显增多。结论：再灌注期间细胞凋亡数较缺血期间明显增多，其原因为包括一氧化氮在内的多种氧自由基表达增高所致。     

Monoclonal ribosomal P autoantibody inhibits the expression and release of IL-12, TNF-alpha and iNOS in activated RAW macrophage cell line

Monoclonal ribosomal P protein antibody (anti-P mAb) may bind to the cell surface, penetrate into cells, and induce apoptosis of Jurkat T cells. Recently, modulation of cytokines has been considered to be important in the pathogenesis of systemic lupus erythematous (SLE). In this study, effects of anti-P mAbs (9B6) on gene expression of cytokines, apoptosis, and reactive oxygen species in murine macrophage RAW 264.7 were analyzed by RT-PCR and ELISA and those on IL-12 promoter activity was determined in an IL-12p40 promoter-reporter gene transfected cell line RAW (IL-12p40-SEAP). After treating LPS-activated RAW 264.7 with 9B6 for 6 or 24 h, the levels of mRNA and protein expression of IL-12, TNF-alpha, and iNOS were significantly inhibited by 25%, 16%, and 13%, respectively. The IL-12 promoter activity of RAW (IL-12p40-SEAP) was also inhibited by 13-22%. However, inhibitory effects were not observed in cells pre-treated with IgG1 for 1 h. The productions of IL-10 in LPS-activated RAW 264.7 and human macrophages were potentiated by 9B6 up to 65% and 51%, respectively. Since anti-P Abs inhibit productions of IL-12 and TNF-alpha and enhance IL-10 production in macrophages, these autoantibodies may augment Th2 responses and amplify lupus manifestations by causing immunological polarity and lymphocyte dysfunction.     

Morphological changes of c-Fos-like immunoreactivity in rat cerebral cortex after cerebral ischemia and reperfusion with special reference to vasoactive intestinal polypeptide

We investigated morphological changes in neurons with c-Fos-like immunoreactivity (c-Fos-LI) after cerebral ischemia by light and electron microscopic immunocytochemistry. Strong c-Fos-LI was observed in layers II–VI of the cerebral cortex with an especially abundant distribution in the nuclei of layers II, IV, and VI ipsilateral to the lesioned side. Reperfusion after ischemia had a greater effect on the expression of c-Fos-LI than did permanent ischemia. Vasoactive intestinal peptide (VIP)-positive neurons were seen scattered in layers II–V of the cerebral cortex. Some VIP-positive neurons showed c-Fos-LI after ischemia. Electron microscopy revealed c-Fos-LI in euchromatin in the nuclei of c-Fos-positive cells. Dilatation of the cisternae of the rough endoplasmic reticulum and the presence of numerous secondary lysosomes were found in neurons on the lesioned side after 12h of reperfusion. Some VIP-containing neurons revealed c-Fos-LI with reperfusion after ischemia by a double immunostaining method on the same tissue section. These findings suggest that ischemia potentiates c-fos expression in VIP- or other transmitter- or modulator-containing neurons, thereby protecting from neuronal cell death.     

Role of superantigenic strains in the prognosis of community-acquired methicillin-susceptible Staphylococcus aureus bacteraemia

Methicillin-susceptible Staphylococcus aureus (MSSA) strains can produce superantigenic toxins that may trigger a massive release of pro-inflammatory cytokines, which are involved in the onset of septic shock. This 1-year prospective pilot study assessed the role of the production of superantigenic toxins in the outcome of immunocompetent patients hospitalised for community-acquired MSSA bacteraemia. Thirty-seven patients were enrolled, of whom 14 died in hospital. Fourteen patients had septic shock, and the mortality rate in this subgroup was 56%. Twenty-seven (73%) isolates produced at least one superantigenic toxin, but this did not influence the rate of occurrence of septic shock or death.     

黄芪注射液腹腔注射脑缺血再灌注模型大鼠海马组织神经元凋亡及半胱氨酸天冬氨酸蛋白酶3的表达*

背景：有研究表明黄芪注射液可抑制脑缺血再灌注大鼠海马神经元凋亡。 目的：观察黄芪注射液腹腔注射脑缺血再灌注大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3的表达。 方法：采用四血管阻断法制备全脑缺血再灌注大鼠模型,建模后给予质量浓度2,4,6,8和10 mL/kg的黄芪注射液腹腔注射,并设立假手术组。分别采用原位末端标记法染色和蛋白免疫印迹方法检测各组大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白表达。 结果与结论：模型组大鼠海马神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达明显增多(P < 0.05);与模型组相比,黄芪注射液4,6,8,10 mL/kg组海马神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达明显减少(P < 0.05);与黄芪注射液4 mL/kg组比,黄芪注射液6,8,10 mL/kg 组神经元凋亡指数及半胱氨酸天冬氨酸蛋白酶3蛋白表达减少(P < 0.05),且呈剂量依赖性。结果证实,黄芪注射液可抑制脑缺血再灌注大鼠海马神经元凋亡及半胱氨酸天冬氨酸蛋白酶3蛋白表达。关键词：黄芪注射液;脑缺血再灌注;不同剂量;半胱氨酸天冬氨酸蛋白酶3;细胞凋亡;中医药;组织构建 doi:10.3969/j.issn.1673-8225.2012.20.031     

Overexpression of inducible nitric oxide synthase and accumulation of 8-OHdG in nasopharyngeal carcinoma

Aims:  Nitric oxide (NO), produced by inducible NO synthase (iNOS), has been suggested to cause oxidative stress, leading to 8-hydroxydeoxyguanosine (8-OHdG) accumulation and subsequent transversion mutation of DNA. The aim was to evaluate iNOS expression and the status of oxidative stress in nasopharyngeal carcinoma (NPC).
Methods and results:  Seventy-three cases of NPC were investigated to examine the immunohistochemical expression of iNOS, 8-OHdG and latent membrane protein-1 (LMP-1) and Epstein–Barr virus-encoded small RNA (EBER) expression using in situ hybridization. iNOS mRNA expression and p53 gene mutations were also assessed. Overexpression of iNOS, LMP-1 and EBER was observed in 62 (84.9%), 28 (38.4%) and 53 (72.6%) cases respectively. p53 gene mutation was found in 10 of 73 (13.7%) cases. Immunohistochemical iNOS expression was associated with the 8-OHdG labelling index, iNOS mRNA expression and p53 gene alteration ( P  < 0.0001, P  = 0.016 and 0.0082 respectively).
Conclusions:  Our present findings suggest that the expression of iNOS induces oxidative stress in NPC. Although the presence of p53 mutation was associated with iNOS overexpression, the type of acid–base change of p53 was transition, but not transversion, which suggests that the p53 gene is not the direct target of DNA damage by 8-OHdG accumulation.