title: Identification of differentially expressed genes in mouse kidney after irradiation using microarray analysis.
abstract: Irradiation of the kidney induces dose-dependent, progressive renal functional impairment, which is partly mediated by vascular damage. The molecular mechanisms underlying the development of radiation-induced nephropathy are unclear. Given the complexity of radiation-induced responses, microarrays may offer new opportunities to identify a wider range of genes involved in the development of radiation injury. The aim of the present study was to determine whether microarrays are a useful tool for identifying time-related changes in gene expression and potential mechanisms of radiation-induced nephropathy. Microarray experiments were performed using amplified RNA from irradiated mouse kidneys (1 x 16 Gy) and from sham-irradiated control tissue at different intervals (1-30 weeks) after irradiation. After normalization procedures (using information from straight-color, color-reverse and self-self experiments), the differentially expressed genes were identified. Control and repeat experiments were done to confirm that the observations were not artifacts of the array procedure (RNA amplification, probe synthesis, hybridizations and data analysis). To provide independent confirmation of microarray data, semi-quantitative PCR was performed on a selection of genes. At 1 week after irradiation (before the onset of vascular and functional damage), 16 genes were significantly up-regulated and 9 genes were down-regulated. During the period of developing nephropathy (10 to 20 weeks), 31 and 42 genes were up-regulated and 9 and 4 genes were down-regulated. At the later time of 30 weeks, the vast majority of differentially expressed genes (191 out of 203) were down-regulated. Potential genes of interest included TSA-1 (also known as Ly6e) and Jagged 1 (Jag1). Increased expression of TSA-1, a member of the Ly-6 family, has previously been reported in response to proteinuria. Jagged 1, a ligand for the Notch receptor, is known to play a role in angiogenesis, and is particularly interesting in the context of radiation-induced vascular injury. The present study demonstrates the potential of microarrays to identify changing patterns of gene expression in irradiated kidney. Further studies will be required to evaluate functional involvement of these genes in vascular-mediated normal tissue injury.
authors.affiliation: The Netherlands Cancer Institute, Division of Experimental Therapy (H6),Amsterdam, The Netherlands.
authors.forename: Jacqueline J C M
authors.initials: JJ
authors.lastname: Kruse
authors.forename: Johannes A M
authors.initials: JA
authors.lastname: te Poele
authors.forename: Arno
authors.initials: A
authors.lastname: Velds
authors.forename: Ron M
authors.initials: RM
authors.lastname: Kerkhoven
authors.forename: Liesbeth J
authors.initials: LJ
authors.lastname: Boersma
authors.forename: Nicola S
authors.initials: NS
authors.lastname: Russell
authors.forename: Fiona A
authors.initials: FA
authors.lastname: Stewart
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D002135:Calcium-Binding Proteins; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation / Q000528:radiation effects*; D036341:Intercellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D007668:Kidney / Q000378:metabolism* / Q000528:radiation effects*; D007674:Kidney Diseases / Q000209:etiology / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods; D000072099:Serrate-Jagged Proteins; D014965:X-Rays / Q000009:adverse effects
chemical_list: D002135:Calcium-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D011506:Proteins; D000072099:Serrate-Jagged Proteins; C084839:thymic shared antigen-1