engleski

Cytokine regulation of the TFF binding protein GKN2(GDDR/TFIZ1/blottin) in human GI epithelial cells

INTRODUCTION: Trefoil factor family (TFF) peptides are major secretory products of mucous epithelia and play a multifunctional role in cytoprotection, apoptosis, and immune response. Recently, a TFF2-binding protein was discovered in mice and named blottin. It is down-regulated in gastric cancer (GDDR), abundant in human gastric surface (TFIZ1) and its similarity to gastrokine-1 led to the gene&#8217; s name gastrokine 2 (GKN2). The aim of our study was to see how the GKN2 gene is regulated by different cytokines. METHOD: GKN2 gene promoter (position &#8211; 1906 to -20) was cloned into luciferase reporter gene plasmid (pGL3 basic vector) and introduced into gastrointestinal cell lines (HT-29, KATO III, AGS). The expression of reporter gene controlled by GKN2 promoter was monitored (Dual Luciferase Assay system) upon treatment with various pro-inflammatory (TNF-&#945; , IL1-&#946; , IL-6, INF-&#947; ) and anti-inflammatory (TGF-&#946; ) cytokines. To assess direct role of transcription factors in regulating GKN2 (NF-&#954; B, p65, HNF-3&#946; , hGATA6) we performed transient co-expression of their expression plasmids and the reporter gene vector. Statistical analysis was performed by using one way ANOVA (*p < 0.05, **p < 0.01). CONCLUSION: Statistically significant down-regulation of GKN2 transcription was observed by TNF-&#945; , IL1-&#946; and IL-6 (Fig 1a, b). Transcription factor NF-&#954; B also inhibits transcription of GKN2 gene (Fig 2). TGF-&#946; and transcription factors hGATA6 and HNF3-&#946; caused an up-regulation of the GKN2 gene (Fig 1a and 3). Various cytokines regulate GKN2 gene expression, suggesting the crosstalk of GKN2 as an TFF interacting protein with immune response.

TFF proteins; blottin; GDDR; TFIZ1; gastrointestinal epithelial cells

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