RESUMEN
BACKGROUND AND AIMS: Interferon regulatory factor-1 (IRF-1) is a transcription factor with antiviral, proinflammatory and tumor suppressor properties. We examined the role of IRF-1 in dextran sulfate sodium colitis, a murine model of inflammatory bowel disease, to determine if absence of the gene would protect against colitis. METHODS: C57BL/6J mice with a targeted disruption of IRF-1 and wild-type C57BL/6J controls received five 7-day cycles of 2% dextran sulfate sodium alternating with five 7-day cycles of water. Colonic tissue was formalin fixed for histological analysis and total RNA extracted for gene chip and SYBR green real-time polymerase chain reaction (PCR) analysis. RESULTS: Histological analysis revealed increased distortion of crypt architecture in the dextran sulfate sodium-treated, IRF-1 -/- animals as compared to dextran sulfate sodium-treated wild-type animals. Five of 15 dextran sulfate sodium-treated IRF-1 -/- mice, but only one of 14 dextran sulfate sodium-treated wild-type mice, developed colonic dysplasia. Microarray analysis comparing colonic gene expression in IRF-1 -/- and wild-type animals revealed decreased expression of caspases, genes involved in antigen presentation, and tumor suppressor genes in the IRF-1 -/- animals. Increased expression of genes involved in carcinogenesis and immunoglobulin and complement genes was also noted in the knock-out animals. CONCLUSIONS: Absence of IRF-1 is not protective in dextran sulfate sodium colitis.
Asunto(s)
Colitis Ulcerosa/genética , Proteínas de Unión al ADN/genética , Sulfato de Dextran/toxicidad , Fosfoproteínas/genética , ARN/genética , Adenocarcinoma/etiología , Adenocarcinoma/genética , Adenocarcinoma/patología , Animales , Enfermedad Crónica , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/metabolismo , Colon/efectos de los fármacos , Colon/patología , Neoplasias del Colon/etiología , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Estudios de Seguimiento , Expresión Génica , Factor 1 Regulador del Interferón , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Análisis por Micromatrices , Fenotipo , Fosfoproteínas/metabolismo , Reacción en Cadena de la Polimerasa , Lesiones Precancerosas , Espectrometría de FluorescenciaRESUMEN
OBJECTIVES: Discovery of Nod2 as the inflammatory bowel disease 1 (IBD1) susceptibility gene has brought to light the significance of mononuclear cells in inflammatory bowel disease pathogenesis. The purpose of this study was to examine changes in gene expression in peripheral blood mononuclear cells in patients with untreated Crohn's disease (CD) and ulcerative colitis (UC) as compared to patients with other inflammatory gastrointestinal disorders and to healthy controls. METHODS: We used a 2400 gene cDNA glass slide array (MICROMAX) to examine gene expression in peripheral blood mononuclear cells from seven patients with Crohn's disease, five patients with ulcerative colitis, 10 patients with other inflammatory gastrointestinal disorders, and 22 age- and sex-matched controls. Results. Novel categories of genes differentially expressed in Crohn's disease and ulcerative colitis patients included genes regulating hematopoietic cell differentiation and leukemogenesis, lipid raft-associated signaling, the actin cytoskeleton, and vesicular trafficking. CONCLUSIONS: Altered gene expression in mononuclear cells may contribute to inflammatory bowel disease pathogenesis.
Asunto(s)
Colitis Ulcerosa/sangre , Colitis Ulcerosa/genética , Enfermedad de Crohn/sangre , Enfermedad de Crohn/genética , Leucocitos Mononucleares/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Perfilación de la Expresión Génica , Humanos , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , ARN Mensajero/metabolismoRESUMEN
BACKGROUND: Polymorphisms in several genes (NOD2, MDR1, SLC22A4) have been associated with susceptibility to Crohn's disease. Identification of the remaining Crohn's susceptibility genes is essential for the development of disease-specific targets for immunotherapy. Using gene expression analysis, we identified a differentially expressed gene on 5q33, the colony stimulating factor 1 receptor (CSF1R) gene, and hypothesized that it is a Crohn's susceptibility gene. The CSF1R gene is involved in monocyte to macrophage differentiation and in innate immunity. METHODS: Patients provided informed consent prior to entry into the study as approved by the Institutional Review Board at LSU Health Sciences Center. We performed forward and reverse sequencing of genomic DNA from 111 unrelated patients with Crohn's disease and 108 controls. We also stained paraffin-embedded, ileal and colonic tissue sections from patients with Crohn's disease and controls with a polyclonal antibody raised against the human CSF1R protein. RESULTS: A single nucleotide polymorphism (A2033T) near a Runx1 binding site in the eleventh intron of the colony stimulating factor 1 receptor was identified. The T allele of this single nucleotide polymorphism occurred in 27% of patients with Crohn's disease but in only 13% of controls (X2 = 6.74, p < 0.01, odds ratio (O.R.) = 2.49, 1.23 < O.R. < 5.01). Using immunohistochemistry, positive staining with a polyclonal antibody to CSF1R was observed in the superficial epithelium of ileal and colonic tissue sections. CONCLUSIONS: We conclude that the colony stimulating factor receptor 1 gene may be a susceptibility gene for Crohn's disease.
