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

• Published in: The Journal of biological chemistry Vol. 279; no. 28; pp. 29670 - 29680
• Main Authors: Sadlier, Denise M, Connolly, Susan B, Kieran, Niamh E, Roxburgh, Sarah, Brazil, Derek P, Kairaitis, Lukas, Wang, Y, Harris, David C H, Doran, Peter, Brady, Hugh R
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 09.07.2004
• Subjects: Animals; Antibiotics, Antineoplastic - toxicity; Cells, Cultured; Cluster Analysis; Disease Models, Animal; Doxorubicin - toxicity; Epithelial Cells - cytology; Epithelial Cells - metabolism; Extracellular Matrix - metabolism; Extracellular Matrix Proteins - genetics; Extracellular Matrix Proteins - metabolism; Fibrosis - chemically induced; Fibrosis - genetics; Fibrosis - metabolism; Fibrosis - pathology; Gene Expression Profiling; Gene Expression Regulation; Kidney Diseases - chemically induced; Kidney Diseases - genetics; Kidney Diseases - metabolism; Kidney Diseases - pathology; Kidney Tubules - cytology; Kidney Tubules - metabolism; Kidney Tubules - pathology; Male; Mice; Mice, Inbred BALB C; Oligonucleotide Array Sequence Analysis; Transcription, Genetic
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M313408200

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 β1-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-1β) 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-β 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.