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Co‐immunolocalizing proteins involved in fructose metabolism and calcitriol regulation in the rat kidney
Author(s) -
Dorcinvil Marline,
Douard Veronique,
Fritzky Luke,
Lagunoff David,
Sabbagh Yves,
Ferraris Ronaldo P.
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.703.3
Subject(s) - fructose , medicine , endocrinology , fructokinase , chemistry , calcitriol , klotho , metabolism , carbohydrate metabolism , cotransporter , kidney , biology , biochemistry , vitamin d and neurology , organic chemistry , sodium
In rodents chronically consuming high fructose diets, serum calcitriol levels decrease markedly and may be linked to increases in serum levels of FGF23 known to regulate expression of CYP27B1 and CYP24A1 that metabolize this active form of vitamin D. To determine the cell types involved in this complex interaction, we used immunohistochemistry of renal biomarkers of fructose metabolism (its transporter GLUT5 and fructokinase (FK)), of FGF23 effects (klotho, the obligate renal FGF23 coreceptor) as well as established biomarkers of proximal (the phosphate cotransporter NaPi2a) and distal (peanut agglutinin (PNA)) tubule cells. NaPi2a but not PNA colocalized with GLUT5 and FK, while GLUT5 colocalized also with FK. Compared to glucose or starch, fructose‐feeding markedly increased expression of GLUT5 and decreased that of NaPi2a. Thus dietary fructose regulates renal fructose transport and metabolism occurring primarily in proximal and not distal tubule cells. In contrast, PNA, but not NaPi2a, GLUT5 and FK, colocalized with klotho, suggesting that klotho and FGF23 regulation occurs mainly in the distal tubule, contrary to most findings, and that fructose metabolism in the proximal tubule may not directly interact with klotho‐regulated calcitriol metabolism. (NSF‐IOS1121049)