In vitro toxicology最新文献

Benzene and Its Principal Metabolites Modulate Proinflammatory Cytokines and Growth Factors in Human Epidermal Keratinocyte Cultures. 苯及其主要代谢物可调节人类表皮角质细胞培养物中的促炎细胞因子和生长因子。

In vitro toxicology Pub Date : 1997-12-01

James L Wilmer, Petia P Simeonova, Dori R Germolec, Michael I Luster

{"title":"Benzene and Its Principal Metabolites Modulate Proinflammatory Cytokines and Growth Factors in Human Epidermal Keratinocyte Cultures.","authors":"James L Wilmer, Petia P Simeonova, Dori R Germolec, Michael I Luster","doi":"","DOIUrl":"","url":null,"abstract":"Benzene is an established leukemogen and hematotoxin in humans. However, the finding that benzene is a multiple-site carcinogen in rodents raises the possibility that other tissues could be susceptible to benzene-induced carcinogenicity, especially since a significant excess of squamous cell carcinomas and papillomas arise from epidermal and oral keratinocytes in benzene-exposed rats. Since inflammation and sustained hyperplasia are two integral components in carcinogenesis, the elaboration of proinflammatory cytokines and growth factors by keratinocytes might provide a mechanistic link between tumor initiation and promotion in benzene-induced cancers. We observed that the principal benzene metabolites, represented by hydroquinone, 1,4-benzoquinone, phenol, 1,2,4-benzenetriol, and catechol, significantly alters the production of transforming growth factor of (TGF)-α and interleukin (IL)-8 in human epidermal keratinocyte cultures. These cytokines represent the primary growth promoting factor and neutrophil chemotactant in the skin, respectively. Cytokine secretion correlated with the known redox potential of individual benzene metabolites and antioxidants, including dimethyl sulfoxide, 1,1,3,3-tetramethylthiourea, and N-acetylcysteine, attenuated the response. Binary combinations of selected benzene metabolites synergized in the induction of IL-8, while benzene, by itself, induced about a three-fold increase in IL-8 production. Taken together, our studies suggest that benzene and many of its phase I metabolites induce inflammatory cytokines and growth factors and this occurs through direct covalent binding or the generation of reactive oxygen species by autooxidation and reduction. The elaboration of proinflammatory cytokines and growth factors by keratinocytes in response to benzene and its principal metabolites may participate in benzene-induced skin carcinogenesis.","PeriodicalId":89152,"journal":{"name":"In vitro toxicology","volume":"10 4","pages":"429-436"},"PeriodicalIF":0.0,"publicationDate":"1997-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001413/pdf/nihms232237.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29537440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of Cytochrome P450 mRNA in Tissue Sections and Cell Lines Using Enzyme-Labeled Fluorescence In Situ Hybridization. 酶标记荧光原位杂交技术检测组织切片和细胞系细胞色素P450 mRNA。

In vitro toxicology Pub Date : 1997-01-01

Catherine Villaroman, Federico M Farin, Jaspreet S Sidhu, Dolphine Oda, Curtis J Omiecinski

{"title":"Detection of Cytochrome P450 mRNA in Tissue Sections and Cell Lines Using Enzyme-Labeled Fluorescence In Situ Hybridization.","authors":"Catherine Villaroman, Federico M Farin, Jaspreet S Sidhu, Dolphine Oda, Curtis J Omiecinski","doi":"","DOIUrl":"","url":null,"abstract":"Cytochrome P450s (P450s) constitute a superfamily of enzymes that metabolize a broad array of xenobiotics. The ability to measure basal and induced levels of P450 mRNA in specific cells and tissues should provide valuable insight regarding the functional role and heterogeneous expression of these enzymes in chemically related diseases. Methodologies for detecting cell-specific mRNA expression patterns typically rely on radiolabeled probes and photographic emulsions, often coupled with long exposure times. These studies were conducted to evaluate an enzyme-labeled fluorescence (ELF) in situ hybridization technique to detect specific P450 mRNA. Deparaffinized, formalin-fixed tissue sections and cells from culture were incubated for 12 hours with 5'-biotinylated 20-base DNA oligomer probes (20-mer). Specific hybridization was detected using a streptavidin alkaline-phosphatase conjugate followed by incubation with the ELF substrate, yielding a bright, yellow-green fluorescent signal. In this study, utility of the technique was demonstrated using cultured rat hepatorna cells, and tissue sections from rat liver and human oral epithelium. Ribonuclease A pretreatment of the sample, omission of the probe, competition with a nonbiotinylated oligomer, and the use of only partially homologous probes served as negative controls to demonstrate the specificity of the hybridization signal. Our results clearly demonstrated the ability of ELF in situ hybridization to discriminately detect cell-specific P450 mRNA in tissue sections and cultured cells. This technique eliminates the use of radioactivity and enables in situ detection of mRNAs with relative ease, efficiency, specificity, and high sensitivity.","PeriodicalId":89152,"journal":{"name":"In vitro toxicology","volume":"10 3","pages":"295-308"},"PeriodicalIF":0.0,"publicationDate":"1997-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3360469/pdf/nihms-374868.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30649097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Tissue-Culture Substratum and Extracellular Matrix Overlay on Liver-Selective and Xenobiotic Inducible Gene Expression in Primary Rat Hepatocytes. 组织培养基质和细胞外基质覆盖层对大鼠原代肝细胞肝脏选择性和外源诱导基因表达的影响。

In vitro toxicology Pub Date : 1994-01-01

J S Sidhu, F M Farin, T J Kavanagh, C J Omiecinski

{"title":"Effect of Tissue-Culture Substratum and Extracellular Matrix Overlay on Liver-Selective and Xenobiotic Inducible Gene Expression in Primary Rat Hepatocytes.","authors":"J S Sidhu, F M Farin, T J Kavanagh, C J Omiecinski","doi":"","DOIUrl":"","url":null,"abstract":"In a previous study (Sidhu et al., 1993), we demonstrated that a combination of certain cell culture media, hormone addition, and extracellular matrix (ECM) overlay coordinately modulated the expression of certain liver-selective genes in primary rat hepatocyte cultures, including the responsiveness of genes to phenobarbital. However, little is known about the interactions between the type of substratum upon which hepatocytes are adhered and the ECM overlay, as codeterminants of liver-selective gene expression. The present study was undertaken to compare specific substrata, including tissue culture-grade plastic, Primaria, and type 1 collagen-coated plastic, in combination with the presence or absence of standard ECM or a growth-factor-reduced ECM overlay. Hepatocyte cultures were assessed either as control cultures or subsequent to treatment for 24 h with phenobarbital (0.1 or 1 mM), or beta-naphthoflavone (22 μM), to monitor responses of hepatocytes to two prototypic gene-inducing agents. Analyses of maintenance and induction of cytochrome P450 and liver-selective gene expression included measures of mRNA levels using Northern blot and slot-blot hybridization and single cell immunofluorescence assays to measure levels of specific cytochrome P450 proteins. The results of these experiments demonstrated that hepatocyte-selective expression, including the absolute level of induction response (relative to those observed in the rat liver in vivo) was highly dependent on the presence of ECM overlay but independent of the substratum employed. As studied herein, the establishment of optimal conditions for primary hepatocyte culture, enabling reproduction of responses observed in vivo, is important to further prospects for in vitro toxicity testing and for investigating molecular mechanisms of phenobarbital-mediated gene regulation.","PeriodicalId":89152,"journal":{"name":"In vitro toxicology","volume":"7 3","pages":"225-242"},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4012392/pdf/nihms-242111.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32333964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

DIFFERENT PATTERNS OF DNA REPLICATION INHIBITION BY BENZO(A)PYRENE AND 3-METHYLCHOLANTHRENE IN MAMMALIAN CELLS IN VITRO. 苯并(a)芘和3-甲基胆蒽对体外哺乳动物细胞DNA复制抑制的不同模式

In vitro toxicology Pub Date : 1991-01-01

J S Lee, J K Park, H H Lee, I S Choi, S D Park

{"title":"DIFFERENT PATTERNS OF DNA REPLICATION INHIBITION BY BENZO(A)PYRENE AND 3-METHYLCHOLANTHRENE IN MAMMALIAN CELLS IN VITRO.","authors":"J S Lee, J K Park, H H Lee, I S Choi, S D Park","doi":"","DOIUrl":"","url":null,"abstract":"TWO METABOLIC ACTIVATION SYSTEMS, EXEMPLI GRATIA S15 FRACTION AND MOUSE EMBRYONIC FIBROBLAST (MEF) FEEDER LAYER, HAVE BEEN SHOWN TO HAVE EFFECTS ON THE PATTERN CHANGE OF BENZO(A)PYRENE (BP)- AND 3-METHYLCHOLANTHRENE (MC)-INDUCED DNA REPLICATION INHIBITION. THE PRESENT STUDIES WERE PERFORMED IN ORDER TO ELUCIDATE THE MECHANISM OF SUCH EFFECTS IN CHINESE HAMSTER OVARY CELLS (CHO-K1) USING ALKALINE SUCROSE GRADIENT SEDIMENTATION ANALYSIS. WHEN CHO-K1 CELLS WERE TREATED WITH BP IN THE ABSENCE OF METABOLIC ACTIVATION SYSTEM, INHIBITION OF REPLICON INITIATION AND CHAIN ELONGATION WAS OBSERVED AT 12 HR AND AT 24 HR, RESPECTIVELY, REGARDLESS OF THE DOSE, EVEN THOUGH THE LEVEL OF THE OVERALL REPLICATION INHIBITION WAS VERY LOW. HOWEVER, WHEN THESE CELLS WERE TREATED WITH BP OR MC IN THE PRESENCE OF THE S15 FRACTION FOR 1 HR, THE RATE OF DNA SYNTHESIS WAS GREATLY DECREASED. AT LOW DOSES BELOW 10(-6) M WHEREAS THE CHAIN ELONGATION WAS MARKEDLY INTERRUPTED AT 10(-4) M. THESE RESULTS SUGGEST THAT THE PATTERN OF DNA REPLICATION INHIBITION INDUCED BY MC OR BP COULD BE INFLUENCED TO A GREATER DEGREE BY THE CHOICE OF METABOLIC ACTIVATION SYSTEM EMPLOYED THAN BY THE DOSE OR THE DURATION OF EXPOSURE.","PeriodicalId":89152,"journal":{"name":"In vitro toxicology","volume":"4 2","pages":"113-20"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"36527224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

POTENTIATION EFFECTS OF 3-AMINOBENZAMIDE ON DIVALENT CATION-DEPENDENT DNA FRAGMENTATION IN MAMMALIAN CELLS EXPOSED TO METHYL METHANESULFONATE. 3-氨基苯甲酰胺对暴露于甲磺酸甲酯的哺乳动物细胞中二价阳离子依赖性DNA片段的增强作用。

In vitro toxicology Pub Date : 1991-01-01

J K Park, I S Park, J S Lee, S D Park

引用次数: 0