title: Translational repression of SLC26A3 by miR-494 in intestinal epithelial cells.
abstract: SLC26A3 [downregulated in adenoma (DRA)] is a Cl(-)/HCO3(-) exchanger involved in electroneutral NaCl absorption in the mammalian intestine. Altered DRA expression levels are associated with infectious and inflammatory diarrheal diseases. Therefore, it is critical to understand the regulation of DRA expression. MicroRNAs (miRNAs) are endogenous, small RNAs that regulate protein expression via blocking the translation and/or promoting mRNA degradation. To investigate potential modulation of DRA expression by miRNA, five different in silico algorithms were used to predict the miRNAs that target DRA. Of these miRNAs, miR-494 was shown to have a highly conserved putative binding site in the DRA 3'-untranslated region (3'-UTR) compared with other DRA-targeting miRNAs in vertebrates. Transfection with pmirGLO dual luciferase vector containing DRA 3'-UTR (pmirGLO-3'-UTR DRA) resulted in a significant decrease in relative luciferase activity compared with empty vector. Cotransfection of the DRA 3'-UTR luciferase vector with a miR-494 mimic further decreased luciferase activity compared with cells transfected with negative control. The transfection of a miR-494 mimic into Caco-2 and T-84 cells significantly increased the expression of miR-494 and concomitantly decreased the DRA protein expression. Mutation of the seed sequences for miR-494 in 3'-UTR of DRA abrogated the effect of miR-494 on 3'-UTR. These data demonstrate a novel regulatory mechanism of DRA expression via miR-494 and indicate that targeting this microRNA may serve to be a potential therapeutic strategy for diarrheal diseases.
authors.affiliation: Division of Gastaroenterology and Hepatology, Dept. of Medicine, UIC Senior Research Career Scientist, Jesse Brown VAMC, 820 South Damen Ave., Chicago, IL 60612. pkdudeja@uic.edu.
authors.forename: Arivarasu N
authors.initials: AN
authors.lastname: Anbazhagan
authors.forename: Shubha
authors.initials: S
authors.lastname: Priyamvada
authors.forename: Anoop
authors.initials: A
authors.lastname: Kumar
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Maher
authors.forename: Alip
authors.initials: A
authors.lastname: Borthakur
authors.forename: Waddah A
authors.initials: WA
authors.lastname: Alrefai
authors.forename: Jaleh
authors.initials: J
authors.lastname: Malakooti
authors.forename: John H
authors.initials: JH
authors.lastname: Kwon
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Dudeja
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D015153:Blotting, Western; D018938:Caco-2 Cells; D027963:Chloride-Bicarbonate Antiporters / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D003001:Cloning, Molecular; D019295:Computational Biology; D003967:Diarrhea / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D035683:MicroRNAs / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D000076988:Sulfate Transporters
chemical_list: D020413:3' Untranslated Regions; D027963:Chloride-Bicarbonate Antiporters; C547168:MIRN494 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger; C081011:SLC26A3 protein, human; D000076988:Sulfate Transporters
keywords: 3′-UTR; DRA; microRNA