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Carbohydrates downregulates sodium‐dependent neutral amino acid transporter‐2 expression (946.5)
Author(s) -
OrtizOrtega Vicor,
MendezGarcia Ana Luisa,
Noriega Lilia Guadalupe,
Torres Nimbe,
Tovar Armando Roberto
Publication year - 2014
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.28.1_supplement.946.5
Subject(s) - sucrose , carbohydrate responsive element binding protein , carbohydrate , gene expression , chemistry , biochemistry , messenger rna , transporter , glucose transporter , transfection , medicine , microbiology and biotechnology , biology , endocrinology , gene , insulin , transcription factor
SNAT has an important physiological role in the provision of amino acids that may enter the gluconeogenic pathway in liver. However, SNAT2 transcriptional regulation by carbohydrates has not been studied. The objective of this study was to determine the acute response to 70% sucrose diet (high sucrose diet, HSD) or 10% sucrose diet (low sucrose diet, LSD) on hepatic SNAT2 expression. Wistar rats fed HSD showed a decrease of hepatic SNAT2 mRNA and protein expression compared with rats fed LSD or fasted rats. Also, we found a decrease SNAT2 mRNA expression in rat hepatocytes primary culture or HepG2 cells incubated with 25 mM versus 5 mM glucose. SNAT2 promoter mapping showed a putative carbohydrate response element (ChoRE). A construct containing this site was ligated in a luciferase vector for functional studies in HepG2 cell line. Promoter activity was decreased when transfection was performed with 25 mM versus 5 mM glucose. Specific protein‐DNA complexes were detected by EMSA indicating that the carbohydrate response element‐binding protein (ChREBP) binds to ChoRE in the SNAT2 promoter. These results showed that sucrose‐fed rats decrease hepatic SNAT2 expression through ChREBP. Grant Funding Source : Supported by CONACyT 183037