title: Expression profiling of selected genes of toxication and detoxication pathways in peripheral blood lymphocytes as a biomarker for predicting toxicity of environmental chemicals.
abstract: To develop a rapid and sensitive tool for determining gene expression profiles of peripheral blood lymphocytes (PBL) as a surrogate for predicting toxicity associated with environmental exposures, studies were initiated using Taqman Low Density Array (TLDA), a medium throughput method for real time PCR (RT-PCR), for selected genes involved in toxication and detoxication processes. Total RNA was prepared from PBL and liver samples isolated from young rats treated with inducers of drug metabolizing enzymes, e.g. phenobarbital (PB, 80mg/kg i.p. X5 days) or methylcholanthrene (30mg/kg, i.p. X5 days) or ethanol (0.8ml/kg, i.p. X1 day). TLDA data showed that PBL expressed drug metabolizing enzymes (DMEs), though the level of expression was several folds lower when compared to liver. Treatment with different inducers of DMEs produced a similar pattern of an increase in the expression of various phase I and phase II DMEs and their respective transcription factors in liver and PBL. While treatment with MC increased the expression of MC inducible cytochrome P450 (CYP) 1A1, 1A2, 1B1, 2A2 & 3A1 and their associated transcription factors in PBL, an increase in the expression of CYP2B1, 2B2, 2C11 & 3A1 and their transcription factor was observed in PBL after PB treatment. Similarly, treatment of ethanol increased the expression of CYP2E1 and 3A1 along with transcription factors in PBL. These inducers were found to increase the expression of various phase II enzymes such as glutathione S-transferases, GSTs (GSTM1, GSTA1, GSTP1 and GSTK1), NQO1, Ephx1 and Sod1, genes involved in inflammation and apoptosis (p53, BCl2, Apaf1 and Caspase9) in both PBL and liver. The data suggests that the low-density array of selected genes in PBL has the potential to be developed as a rapid and sensitive tool for monitoring of individuals exposed to environmental chemicals as well as in clinical studies.
authors.affiliation: Developmental Toxicology Division, Indian Institute of Toxicology Research (Council of Scientific and Industrial Research), M.G. Marg, Lucknow 226 001, UP, India; Department of Biotechnology, Jamia Hamdard, Hamdard Nagar, New Delhi 110 062, India.
authors.forename: Amit
authors.initials: A
authors.lastname: Sharma
authors.forename: Kumar
authors.initials: K
authors.lastname: Saurabh
authors.forename: Sanjay
authors.initials: S
authors.lastname: Yadav
authors.forename: Swatantra K
authors.initials: SK
authors.lastname: Jain
authors.forename: Devendra
authors.initials: D
authors.lastname: Parmar
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015415:Biomarkers / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D004785:Environmental Pollutants / Q000009:adverse effects / Q000494:pharmacology*; D000431:Ethanol / Q000494:pharmacology; D007249:Inflammation / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008214:Lymphocytes / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D050216:Metabolic Detoxication, Phase I / Q000235:genetics*; D050217:Metabolic Detoxication, Phase II / Q000235:genetics*; D008748:Methylcholanthrene / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology; D012313:RNA / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome / Q000187:drug effects
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D014157:Transcription Factors; D000431:Ethanol; D008748:Methylcholanthrene; D012313:RNA; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital