title: Genes regulated by Nkx2-3 in siRNA-mediated knockdown B cells: implication of endothelin-1 in inflammatory bowel disease.
abstract: Nkx2-3 gene variants are strongly associated with inflammatory bowel disease (IBD) and its expression is up-regulated in Crohn's disease (CD). However, the nature of its role underlying IBD pathogenesis is unknown. We investigated the genes regulated by Nkx2-3 using cDNA microarray. A small interfering RNA (siRNA)-mediated knockdown of Nkx2-3 in a B cell line from a CD patient was generated. Gene expression was profiled on high-density cDNA microarrays representing over 25,000 genes. Ingenuity pathway analysis (IPA) was used to identify gene networks according to biological functions and associated pathways. Expression profiling analysis by cDNA microarray showed that 125 genes were regulated by Nkx2-3 knockdown (fold change >or=3.0, p<0.01), among which 51 genes were immune and inflammatory response genes. Microarray results were validated by RT-PCR and further confirmed in a B cell line expressing siRNA of Nkx2-3 from an additional CD patient. The results showed that Nkx2-3 was up-regulated (p<0.05) and EDN1 was down-regulated (p<0.05) in B cell lines from CD patients. mRNA expression levels of Nkx2-3 were negatively correlated with those of EDN1 (r=-0.6044, p<0.05). EDN1 was also down-regulated in intestinal tissues from UC patients (p<0.05). Our present results demonstrate that a decrease in Nkx2-3 gene expression level can profoundly alter the expression of genes and cellular functions relevant to the pathogenesis and progression of IBD, such as EDN1.
authors.affiliation: Department of Surgery, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA. ZLIN@hmc.psu.edu
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.forename: Zhenwu
authors.initials: Z
authors.lastname: Lin
authors.forename: John P
authors.initials: JP
authors.lastname: Hegarty
authors.forename: Gerrit
authors.initials: G
authors.lastname: John
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.forename: Pieter W
authors.initials: PW
authors.lastname: Faber
authors.forename: Ashley A
authors.initials: AA
authors.lastname: Kelly
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Wang
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Poritz
authors.forename: Stefan
authors.initials: S
authors.lastname: Schreiber
authors.forename: Walter A
authors.initials: WA
authors.lastname: Koltun
mesh_terms: D001402:B-Lymphocytes / Q000502:physiology*; D003424:Crohn Disease / Q000235:genetics / Q000503:physiopathology; D015536:Down-Regulation; D019332:Endothelin-1 / Q000235:genetics* / Q000502:physiology; D020869:Gene Expression Profiling; D018398:Homeodomain Proteins / Q000502:physiology*; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D034741:RNA, Small Interfering / Q000235:genetics; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D019332:Endothelin-1; D018398:Homeodomain Proteins; C534957:NKX2-3 protein, human; D034741:RNA, Small Interfering; D014157:Transcription Factors