吡格列酮对脂多糖诱导星形胶质细胞诱导型一氧化氮合酶表达的抑制作用

目的 研究吡格列酮(Pio)对脂多糖 (LPS) 诱导星形胶质细胞(AC)诱导型一氧化氮合酶(iNOS)的抑制作用及其作用机制。方法 AC分别加入Pio 0.1, 1.0和10.0 μmol·L^-1, c-Jun氨基端激酶(JNK)抑制剂SP600125 20.0 μmol·L^-1, p38丝裂原活化蛋白激酶(p38MAPK)抑制剂SB203580 20.0 μmol·L^-1或过氧化物酶体增殖物激活受体γ(PPARγ)抑制剂GW9662 10.0 μmol·L^-1,1 h以后加入LPS 10.0 mg·L^-1, 继续作用24 h。Griess法测定培养AC上清液中一氧化氮(NO)含量。免疫印迹法和免疫荧光法检测iNOS的表达水平。结果 与正常对照组相比,LPS 10.0 mg·L^-1组iNOS表达水平和NO分泌水平均显著增高(P<0.01)。Pio 0.1, 1.0和10.0 μmol·L^-1可明显抑制LPS诱导的iNOS表达上调及NO分泌增加(P<0.05),Pio 10.0 μmol·L^-1组iNOS蛋白表达水平由LPS组1.711±0.283下降到0.157±0.082(P<0.01),NO分泌量由LPS组(16.63±2.25)μmol·L^-1下降到(6.92±1.30)μmol·L^-1(P<0.01)。GW9662 10.0 μmol·L^-1可抑制Pio 1.0 μmol·L^-1的上述作用,iNOS蛋白表达水平由Pio 1.0 μmol·L^-1组0.562±0.100增加到0.847±0.088(P<0.01),NO分泌量由(9.27±1.23)μmol·L^-1增加到(15.54±2.30)μmol·L^-1(P<0.01)。SB203580 20.0 μmol·L^-1和SP600125 20.0 μmol·L^-1的作用与Pio作用相似,使iNOS蛋白表达水平降低到0.434±0.082和0.434±0.076,NO分泌量下降到(11.53±2.40)μmol·L^-1和(8.81±0.58)μmol·L^-1;而单独应用SB203580 20.0 μmol·L^-1和SP600125 20.0 μmol·L^-1对AC的iNOS表达和NO分泌没有影响。结论 Pio能通过抑制LPS诱导的大鼠皮质AC的iNOS表达,从而减少NO的分泌,这种抑制作用可能与其激活PPARγ和阻断JNK和p38MARK信号转导通路有关。     

钩藤碱对缺血再灌注诱导大鼠星形胶质细胞损伤的作用

目的:以原代培养的大鼠大脑星形胶质细胞进行缺血再灌注损伤处理,观察钩藤碱(Rsy)对星形胶质细胞损伤的保护作用.方法:1～3 d龄SD大鼠乳鼠大脑星形胶质细胞原代培养,含连二亚硫酸钠的无糖Earle's液进行缺血缺氧处理造模,MTT法测定细胞存活率,Hoechst 33258荧光显微镜观察细胞形态学变化,流式细胞仪检测细胞坏死、凋亡率,用LDH试剂盒测定LDH漏出率.结果:与模型组比较,钩藤碱0.02、0.2 mg·mL-1均能显著提高细胞存活率,显著降低细胞坏死率和细胞凋亡率,也能显著降低细胞LDH漏出率.结论:钩藤碱对缺血再灌注损伤后星形胶质细胞的坏死凋亡具有显著抑制作用,提示钩藤碱可能通过抑制星形胶质细胞凋亡和坏死而对脑缺血损伤产生保护作用.     

知母皂苷对脂多糖引起星形胶质细胞炎症因子释放的影响及机制

目的研究知母皂苷(SAaB)对脂多糖(LPS)诱导的星形胶质细胞(AC)炎症因子释放的抑制作用及JNK信号传导通路对其的影响。方法实验设对照组、LPS组、SAaB组和阻断剂组。ELISA法和Griess法分别测定各组AC培养液中TNF-α和NO的含量;Western blot检测AC磷酸化JNK和磷酸化c-Jun蛋白表达水平的改变;免疫荧光染色法观察AC的磷酸化ATF-2蛋白表达水平。结果 AC在LPS(10mg.L-1)刺激下TNF-α和NO的分泌、磷酸化JNK1、磷酸化c-Jun和磷酸化ATF-2蛋白表达水平与正常对照组比较均明显增高。特异性JNK特异性阻断剂SP600125(10μmol.L-1)可明显抑制LPS引起的TNF-α和NO产生增加以及磷酸化ATF-2蛋白表达水平;SAaB(1、10、100μmol.L-1)则可明显降低TNF-α和NO产生,下调磷酸化JNK、磷酸化c-Jun和磷酸化ATF-2的蛋白表达水平。结论 SAaB能明显抑制LPS诱导的大鼠皮层AC炎症因子的释放,这种作用可能与其下调JNK信号转导通路有关。     

雌激素上调小鼠长骨c-fos和c-jun表达水平

目的　考察雌酚酮对骨组织c fos和c jun表达的影响 ,为研究雌激素对骨的作用机制积累资料。方法　用体外培养胎鼠长骨考察了雌酚酮对骨生长的作用 ,并采用免疫组织化学方法测定了其对骺板静止区、增殖区和肥大区c fos和c jun蛋白质表达的影响。结果　雌酚酮在体外能促进长骨生长 ,并在 10 -9mol·L-1～ 10 -7mol·L-1浓度范围内以剂量依赖的方式上调 3个区c fos和c jun蛋白质表达水平。结论　提示雌酚酮可能通过上调c fos和c jun在软骨细胞的表达而促进含有AP 1结合位点的、与骨生长发育有关的基因转录和表达 ,从而促进骨生长     

芍药苷通过调控硫氧还蛋白结合蛋白表达对脂多糖诱导的肾小球系膜细胞氧化应激及凋亡的影响

目的 探讨芍药苷对脂多糖(LPS)诱导的肾小球系膜细胞氧化应激及凋亡的影响及其作用机制.方法 研究起止时间为2018年1月至2019年7月,体外培养人肾小球系膜细胞(HMCL),用不同浓度的(5、10、20μmol/L)芍药苷处理LPS诱导的HMCL细胞.采用流式细胞仪检测细胞凋亡率;应用试剂盒检测细胞中丙二醛(MDA)量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性;实时荧光定量聚合酶链反应(qRT-PCR)与蛋白质迹法(Western blotting)分别检测硫氧还蛋白结合蛋白(Thioredoxin-interacting protein,TXNIP)表达;观察干扰TXNIP的表达对LPS诱导的HMCL细胞氧化应激与凋亡的影响.结果 与对照组(Con)比较,LPS组细胞凋亡率升高[(6.58±0.66)％比(28.41±2.83)％](P<0.05),MDA含量增加[(1.26±0.13)nmol/L比(5.06±0.49)nmol/L](P<0.05),SOD[(26.41±2.31)U/mL比(12.46±1.21)U/mL]、GSH-Px[(45.61±4.13)U/mL比(8.12±0.83)U/mL]活性下降(P<0.05),TXNIP信使RNA(mRNA)及蛋白表达升高[(1.02±0.09)vs(2.54±0.25);(0.42±0.04)比(0.87±0.05)](P<0.05);与LPS组比较,芍药苷不同剂量组细胞凋亡率降低[(28.41±2.83)％比(22.16±2.17)/(16.48±1.03)/(11.25±1.12)％](P<0.05),MDA含量下降[(5.06±0.49)nmol/L比(4.12±0.41)/(2.94±0.29)/(1.68±0.17)nmol/L](P<0.05),SOD[(12.46±1.21)U/mL比(15.46±1.52)/(18.24±1.63)/(22.54±2.03)U/mL]、GSH-Px[(8.12±0.83)U/mL比(17.62±1.74)/(26.14±2.63)/(39.44±3.25)U/mL]活性升高(P<0.05),TXNIP mRNA及蛋白表达降低[(2.54±0.25)比(2.13±0.21)/(1.84±0.17)/(1.46±0.15);(0.87±0.05)比(0.72±0.05)/(0.61±0.04)/(0.49±0.03)](P<0.05);干扰TXNIP的表达可减轻LPS诱导的HMCL细胞氧化应激损伤,降低细胞凋亡率;TXNIP过表达可逆转芍药苷对LPS诱导的HMCL细胞氧化应激及凋亡的作用.结论 芍药苷可通过抑制TXNIP的表达对LPS诱导的HMCL细胞氧化应激发挥保护作用,抑制细胞凋亡.     

Inhibitory effect of trilinolein on endothelin-1-induced c-fos gene expression in cultured neonatal rat cardiomyocytes

Trilinolein, isolated from the traditional Chinese herb Sanchi (Panax notoginseng), has been shown to have myocardial protective effects via its antioxidant ability. However, the cellular and molecular mechanisms of the protective effect of trilinolein in the heart remain to be elucidated. Oxidative mechanisms have been implicated in neonatal cardiomyocyte hypertrophy. We previously reported that ET-1 induces ROS generation via the ET_A receptor and ROS modulates c-fos gene expression. We have therefore examined whether trilinolein attenuates ROS production and ET-1-induced c-fos gene expression in cardiomyocytes. Cultured neonatal rat cardiomyocytes were stimulated with ET-1 (10 nM), and c-fos gene expression was examined. Trilinolein (1 and 10 μM) inhibited ET-1-induced c-fos gene expression in cardiomyocytes. We also examined the effects of trilinolein on ET-1- increased NADPH oxidase activity and superoxide formation. Trilinolein inhibited ET-1-increased NADPH oxidase activity and superoxide formation in a concentration-dependent manner. This increase in superoxide production by ET-1 was significantly inhibited by trilinolein, diphenyleneiodonium, or N-acetylcysteine. Trilinolein also decreased ET-1- or H₂O₂-induced extracellular signal-regulated kinase (ERK) phosphorylation, c-Jun NH₂-terminal kinase (JNK) phosphorylation, and activator protein-1 activation. These data indicate that trilinolein inhibits ET-1-induced ERK phosphorylation, JNK phosphorylation, and c-fos gene expression via attenuating superoxide production in cardiomyocytes. Hung-Yu Yang and Ju-Chi Liu equally contributed to this work     

白细胞介素1β及肿瘤坏死因子α对大鼠肝星状细胞c-jun基因表达的调节作用

目的 探讨白细胞介素-1β(IL-1β)、肿瘤坏死因子α(TNFα)对大鼠鼠肝星状细胞c-jun基因表达的影响。方法在培养的肝星状细胞系中加入IL-1βg/L、TNFα30μ/L，于8h、24h、48h、72h4个时间点收集细胞，提取总RNA；用逆转录定量PCR方法测定c-jun的基因表达水平。结果IL-1β组肝星状细胞c-jun基因表达水平在8h、24h、48h3个时间点均明显高于对照组；8h最高，为对照组的3倍。TNFα组肝星状细胞c-jun的基因表达水平在8h、24h、48h、72h均明显高于对照组：8h最高，为对照组的4倍。结论IL-1β、TNFα可增强肝星状细胞c-jun基因的表达。     

Regulation of the hepatic multidrug resistance gene expression by endotoxin and inflammatory cytokines in mice

P-glycoprotein (PGP), an ATP-dependent membrane transporter is found in epithelial tissues of the liver, kidneys, intestine and blood-brain barrier. In tumor cells, PGP is often overexpressed and confers multidrug resistance toward cancer chemotherapeutics. It has been previously shown in rats that induction of an inflammatory response evokes a decrease in hepatic expression of PGP. In order to identify the inflammatory mediators involved in this phenomenon, we examined the influence of experimentally induced inflammation and pro-inflammatory cytokines (interleukin (IL)-6, IL-1beta and tumor necrosis factor (TNF)-alpha) on the hepatic expression of PGP in mice. A significant reduction in the hepatic expression of mdr1a, mdr1b, mdr2 and spgp genes were seen in endotoxin (lipopolysaccharide (LPS)) and turpentine-treated mice. Similarly, IL-6-treated mice displayed a 70% reduction in protein expression and a 40-70% reduction in the mRNA levels of all PGP mdr isoforms. Administration IL-1beta caused an increase in both mdr1b mRNA and protein expression, however, mRNA levels of mdr1a, mdr2 and spgp were significantly reduced. Administration of TNF-alpha also caused increases in mdr1b mRNA. These findings indicate that IL-6 plays a principal role in the downregulation of PGP that is observed in the livers of mice during an inflammatory response.     

“益肝康”大鼠药物血清对HSCsc-fos、c-jun基因表达的影响

目的观察＂益肝康＂药物血清对HSCsc-fos、c-jun基因表达的影响,试图从基因转录水平探讨＂益肝康＂的抗肝纤维化作用机制。方法制备肝纤维化模型鼠,造模成功后,药物组以每天20ml/kg剂量分2次灌服＂益肝康＂;对照组灌以等量0.9%氯化钠溶液。连续给药6d后经下腔静脉取血并分离血清。采用盲法,用上述10%药物血清培养HSCs24h后,采用RT-PCR技术检测c-fos、c-junmRNA的表达情况。结果①电泳条带的光密度扫描显示,B、D组c-fosmRNA的表达与C组比较有差异有统计学意义（P〈0.05）;B、D组与A组比较,c-fosmRNA的表达亦明显下降（P〈0.05）;②光密度扫描显示,B、D组c-junmRNA的表达同C组比较,差异有统计学意义（P〈0.05）;B、D组与A组比较,c-junmRNA的表达亦明显受到抑制（P〈0.05）。结论活化的HSCs表达较高水平的c-fos与c-junmRNA,表明c-fos与c-jun立早基因可能参与了其增殖过程;＂益肝康＂药物血清均能显著下调c-fos与c-junmRNA的表达,在转录水平对c-fos与c-jun的调节可能是两者发挥其抗肝纤维化作用靶点之一。     

Regulation of gene expression by tobacco product preparations in cultured human dermal fibroblasts

Skin fibroblasts comprise the first barrier of defense against wounds, and tobacco products directly contact the oral cavity. Cultured human dermal fibroblasts were exposed to smokeless tobacco extract (STE), total particulate matter (TPM) from tobacco smoke, or nicotine at concentrations comparable to those found in these extracts for 1 h or 5 h. Differences were identified in pathway-specific genes between treatments and vehicle using qRT-PCR. At 1 h, IL1α was suppressed significantly by TPM and less significantly by STE. Neither FOS nor JUN was suppressed at 1 h by tobacco products. IL8, TNFα, VCAM1, and NFκB1 were suppressed after 5 h with STE, whereas only TNFα and NFκB1 were suppressed by TPM. At 1 h with TPM, secreted levels of IL10 and TNFα were increased. Potentially confounding effects of nicotine were exemplified by genes such as ATF3 (5 h), which was increased by nicotine but suppressed by other components of STE. Within 2 h, TPM stimulated nitric oxide production, and both STE and TPM increased reactive oxygen species. The biological significance of these findings and utilization of the gene expression changes reported herein regarding effects of the tobacco product preparations on dermal fibroblasts will require additional research.     

硝普钠抑制脂多糖诱导的大鼠原代培养肝细胞表面细胞间粘附分子-1的表达

目的　评价模拟肝脏急性炎症期一氧化氮与细胞间粘附分子 1(ICAM 1)表达的关系。方法　用免疫细胞化学技术检测加入不同浓度NO供体硝普钠 (SNP)和 (或 )细菌内毒素 (LPS)后 ,原代培养大鼠肝细胞ICAM 1的表达情况。结果　当培养时间达4h ,各组肝细胞均未见ICAM 1显著表达 ;但当培养至 8,2 4h ,LPS组的肝细胞ICAM 1表达强度明显升高 (P <0 .0 5 ) ,SNP则可呈浓度依赖性地抑制LPS诱导的大鼠肝细胞ICAM 1的表达。结论　SNP可显著抑制LPS诱导的原代培养大鼠肝细胞ICAM 1表达。     

Calcineurin and Erk1/2-signaling pathways are involved in the antiapoptotic effect of cyclosporin A on astrocytes exposed to simulated ischemia in vitro

The present study focused on mechanisms involved in the anti-apoptotic effect of cyclosporin A (CsA) towards ischemic injured astrocytes in vitro [under combined oxygen glucose deprivation (OGD)]. We investigated whether this action might be mediated through activation of extracellular signal regulated kinases 1 and 2 (Erk1/2) or attenuation of calcineurin (CaN) by immunosuppressant in ischemic astrocytes. Additionally, the influence of CsA on phosphorylation of Akt kinase was determined. After 21 days of in vitro culture, astrocytes were subjected to OGD (for 8 h) and CsA (0.25–10 μM); 0.25 μM CsA distinctly stimulated the Erk1/2 pathway in astrocytes exposed to OGD. This protective effect of CsA was strongly associated with CaN inhibition, increased expression of anti-apoptotic factors such as Bcl-X_L and NF-κB, as well as suppression of caspase-3 activity. Maximum p-Akt kinase expression was observed following treatment with 1 μM CsA. Finally, we also demonstrated that the beneficial effect of CsA at a concentration of 10 μM is related mainly to strong CaN inhibition. The results obtained suggest that, depending on the concentration used, CsA might act as a protective agent towards ischemia-injured astroglial cells through alternative intracellular pathways associated with increased p-Erk1/2 and p-Akt expression or CaN inactivation.     

In vitro effect of vanadyl sulfate on cultured primary astrocytes: cell viability and oxidative stress markers.

Exposure to vanadium has been associated with deleterious effects on the central nervous system in animals and humans. Although vanadium-derived pro-oxidant species were reported to be involved in vanadium-mediated neurotoxicity, the ability of this metal to induce oxidative stress markers in glial cells remains to be elucidated. In this study, we investigated the cytotoxicity and the generation of reactive oxygen species (ROS) and nitric oxide (NO) by mouse primary astrocytes after treatment with vanadyl sulfate (VOSO₄) at concentrations of 20, 50, 100, 200, and 500 μM. The resazurin assay revealed that treatment with VOSO₄ for 24 and 48 h at concentrations of 50 and 100 μM, respectively, or higher substantially induced astrocytic cytotoxicity. Intracellular ROS increased after 6-h exposure to the lowest concentration tested (20 μM VOSO₄) and tended to intensify after 24- and 48-h treatments reaching significant values for 20 and 500 μM VOSO₄. In turn, NO production in the examined cells was elevated after exposure to all concentrations at the 6-, 24-, and 48-h incubation periods. Our study demonstrated the ability of VOSO₄ to induce H₂O₂ generation in cell-free DMEM/F12 medium. The H₂O₂ levels were in the micromolar range (up to 5 μM) and were detected mostly during the first few minutes after VOSO₄ addition, suggesting that the generated H₂O₂ could not induce toxic effects on the cells. Taken together, these results show VOSO₄ induced cytotoxicity in primary astrocyte cells, which may have resulted from vanadyl-stimulated intracellular ROS and NO generation in these cells.     

Regulation of expression of drug-metabolizing enzymes by oncogenic signaling pathways in liver tumors: a review

Mutations in genes encoding key players in oncogenic signaling pathways trigger specific downstream gene expression profiles in the respective tumor cell populations. While regulation of genes related to cell growth, survival, and death has been extensively studied, much less is known on the regulation of drug-metabolizing enzymes (DMEs) by oncogenic signaling. Here, a comprehensive review of the available literature is presented summarizing the impact of the most relevant genetic alterations in human and rodent liver tumors on the expression of DMEs with a focus on phases I and II of xenobiotic metabolism. Comparably few data are available with respect to DME regulation by p53-dependent signaling, telomerase expression or altered chromatin remodeling. By contrast, DME regulation by constitutive activation of oncogenic signaling via the RAS/RAF/mitogen-activated protein kinase (MAPK) cascade or via the canonical WNT/β-catenin signaling pathway has been analyzed in greater depth, demonstrating mostly positive-regulatory effects of WNT/β-catenin signaling and negative-regulatory effects of MAPK signaling. Mechanistic studies have revealed molecular interactions between oncogenic signaling and nuclear xeno-sensing receptors which underlie the observed alterations in DME expression in liver tumors. Observations of altered DME expression and inducibility in liver tumors with a specific gene expression profile may impact pharmacological treatment options.     

Evaluation of toxicity indicators in rat primary astrocytes, C6 glioma and human 1321N1 astrocytoma cells: can gliotoxicity be distinguished from cytotoxicity?

A comparison was made of rat primary astrocytes, C6 glioma cells pre-treated with dibutyryl cyclic AMP, and the human astrocyte 132N1 cell line using a range of 40 compounds and the neutral red (NR) assay. The 40 chemicals included substances known to be toxic to astrocytes or neurons, to be generally cytotoxic or not thought to be toxic to nervous tissue. For those compounds which were toxic, changes in glial fibrillary acidic protein (GFAP) levels were measured in the primary and C6 cultures, and changes in vimentin and S-100 measured in the C6 cells. The number of compounds with EC₅₀ values <2000 μg/ml for the NR assay for the different cell cultures were as follows: primary astrocytes, 19; C6 cells, 15; and 1321N1 cells, 11. The log of the EC₅₀ values for the NR assay for the test compounds between the three cell types was not significantly different at the 5% level by paired Student's t-test. For the toxic substances the correlation coefficients of the EC₅₀ values between primary cells and the C6 or 1321N1 cells were r>0.5, and between the C6 and 1321N1 cells r>0.9. For GFAP there was a similar degree of correlation in EC₅₀ values between the different cell types. The GFAP, vimentin and S-100 levels showed similar EC₅₀ values for the toxicants, but were not as sensitive as the NR assay. The toxic substances caused altered morphology in the primary, C6 and 1321N1 cells, with increased branching of cell processes. The combined astrocyte systems identified 8 out of 9 substances reported to be toxic to astrocytes in vivo, together with substances which have general cytotoxic properties. A␣number of substances (including the 1 out of 9 reported gliotoxic substances), which may primarily affect neurons, which may affect nervous tissue after long-term exposure, or which are not thought to be toxic to nervous tissue, were not detected. The astrocyte systems positively identify gliotoxic and cytotoxic substances and will allow detailed mechanistic studies to be made on the different underlying mechanisms. Received: 26 January 1998 / Accepted: 3 February 1998     

Regulation of CYP2B6 and CYP3A expression by hydroxymethylglutaryl coenzyme A inhibitors in primary cultured human hepatocytes.

The effects of treatment with the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) inhibitors lovastatin, simvastatin, pravastatin, fluvastatin, and atorvastatin on the contents of cytochrome p450 mRNAs were examined in primary cultures of human hepatocytes prepared from three different livers. Treatment of 2- to 3-day-old human hepatocyte cultures with 3 x 10(-5) M lovastatin, simvastatin, fluvastatin, or atorvastatin for 24 h increased the amounts of CYP2B6 and CYP3A mRNA by an average of 3.8- to 9.2-fold and 24- to 36-fold, respectively. In contrast, pravastatin treatment had no effect on the mRNA level of either CYP2B6 or CYP3A, although treatment with pravastatin did produce the expected compensatory increase in HMG-CoA reductase mRNA content, indicating effective inhibition of cholesterol biosynthesis. Although treatment with the active (+), but not the inactive (-), enantiomer of atorvastatin increased the amount of HMG-CoA reductase mRNA, treatment with each enantiomer significantly induced both CYP2B6 and CYP3A mRNA levels. Treatment of primary cultured rat hepatocytes with the atorvastatin enantiomers effectively increased the amount of CYP3A mRNA, but had no effect on CYP2B or CYP4A mRNA levels, in contrast to fluvastatin, which increased both. Findings for p450 proteins by Western blotting were consistent with the mRNA results. These findings indicate that the ability of a drug to inhibit HMG-CoA reductase activity does not predict its ability to produce p450 induction in primary cultured human hepatocytes, and demonstrate that some, but not all, of the effects of these drugs that occur in primary cultured rat hepatocytes are conserved in human hepatocyte cultures.