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Modulation of αENaC mRNA expression under different stresses: Implication of its 3′UTR.
Author(s) -
Migneault Francis,
Pascariu Mihai,
Dagenais André,
Berthiaume Yves
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.914.6
Subject(s) - epithelial sodium channel , messenger rna , microbiology and biotechnology , untranslated region , cycloheximide , chemistry , transfection , transcription (linguistics) , biology , protein biosynthesis , gene , sodium , biochemistry , linguistics , philosophy , organic chemistry
Active sodium transport by the epithelial Na+ channel (ENaC) is important for fluid movement across the alveolar epithelium in the lungs and for the resolution of pulmonary oedema in acute respiratory distress syndrome (ARDS). It was shown that cellular stress induced by lipopolysaccharides (LPS) or cycloheximide (Chx) downregulate αENaC mRNA via different molecular mechanisms. The purpose of this project was to investigate the importance of the αENaC 3′UTR in the mRNA modulation of ENaC. Alveolar epithelial cells were co‐transfected with 3′UTR mutants (V5/ENaC±3′UTR and Luc±3′UTR) inserted in pTRE‐tight vector along with the Tet‐Off vector. The cells were treated with Chx (1.0μM), LPS (15μg/mL) or Actinomycin D (5μg/mL) along with Dox (1μg/mL) to inhibit transcription. We found that 3′UTR deletion caused a ~60% decrease of luciferase activity and expression compared to the complete recombinant. The T 1/2 of V5‐αENaC mRNA was 60 min and the deletion of 3′UTR reduced T 1/2 to 37min. Chx reduced αENaC mRNA T 1/2 to 33min whereas LPS had no effect. Actinomycin D, a transcription inhibitor, increased T 1/2 >; 120min. These results suggest that the αENaC mRNA half‐life is shorter then previously estimated and that 3′UTR seems to be important for the stability of αENaC mRNA. Supported by FRSQ, CFC and CIHR.