title: Sequential extracellular matrix-focused and baited-global cluster analysis of serial transcriptomic profiles identifies candidate modulators of renal tubulointerstitial fibrosis in murine adriamycin-induced nephropathy.
abstract: Transcriptome analysis using microarray technology represents a powerful unbiased approach for delineating pathogenic mechanisms in disease. Here molecular mechanisms of renal tubulointerstitial fibrosis (TIF) were probed by monitoring changes in the renal transcriptome in a glomerular disease-dependent model of TIF (adriamycin nephropathy) using Affymetrix (mu74av2) microarray coupled with sequential primary biological function-focused and secondary "baited"-global cluster analysis of gene expression profiles. Primary cluster analysis focused on mRNAs encoding matrix proteins and modulators of matrix turnover as classified by Onto-Compare and Gene Ontology and identified both molecules and pathways already implicated in the pathogenesis of TIF (e.g. transforming growth factor beta1-CTGF-fibronectin-1 pathway) and novel TIF-associated genes (e.g. SPARC and Matrilin-2). Specific gene expression patterns identified by primary extracellular matrix-focused cluster analysis were then used as bioinformatic bait in secondary global clustering, with which to search the renal transcriptome for novel modulators of TIF. Among the genes clustering with ECM proteins in the latter analysis were endoglin, clusterin, and gelsolin. In several notable cases (e.g. claudin-1 and meprin-1beta) the pattern of gene expression identified in adriamycin nephropathy in vivo was replicated during transdifferentiation of renal tubule epithelial cells to a fibroblast-like phenotype in vitro on exposure to transforming growth factor-beta and epidermal growth factor suggesting a role in fibrogenesis. The further exploration of these complex gene networks should shed light on the core molecular pathways that underpin TIF in renal disease.
authors.affiliation: Department of Medicine and Therapeutics, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Mater Misericordiae University Hospital and Dublin Molecular Medicine Centre, Dublin, Ireland. dsadlier.genome@mater.ie
authors.forename: Denise M
authors.initials: DM
authors.lastname: Sadlier
authors.forename: Susan B
authors.initials: SB
authors.lastname: Connolly
authors.forename: Niamh E
authors.initials: NE
authors.lastname: Kieran
authors.forename: Sarah
authors.initials: S
authors.lastname: Roxburgh
authors.forename: Derek P
authors.initials: DP
authors.lastname: Brazil
authors.forename: Lukas
authors.initials: L
authors.lastname: Kairaitis
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: David C H
authors.initials: DC
authors.lastname: Harris
authors.forename: Peter
authors.initials: P
authors.lastname: Doran
authors.forename: Hugh R
authors.initials: HR
authors.lastname: Brady
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000633:toxicity*; D002478:Cells, Cultured; D016000:Cluster Analysis; D004195:Disease Models, Animal; D004317:Doxorubicin / Q000633:toxicity*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005355:Fibrosis / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007674:Kidney Diseases / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D007684:Kidney Tubules / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020411:Oligonucleotide Array Sequence Analysis; D014158:Transcription, Genetic
chemical_list: D000903:Antibiotics, Antineoplastic; D016326:Extracellular Matrix Proteins; D004317:Doxorubicin