251. High glucose increases metallothionein expression in renal proximal tubular epithelial cells.
- Author
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Ogawa D, Asanuma M, Miyazaki I, Tachibana H, Wada J, Sogawa N, Sugaya T, Kitamura S, Maeshima Y, Shikata K, and Makino H
- Subjects
- Animals, Antioxidants metabolism, Cell Line, Diabetic Nephropathies metabolism, Epithelial Cells drug effects, Epithelial Cells metabolism, Gene Expression drug effects, Glucose metabolism, Kidney Tubules, Proximal cytology, Male, Metallothionein genetics, Mice, Oxidative Stress drug effects, Rats, Rats, Sprague-Dawley, Vitamin E pharmacology, Glucose pharmacology, Kidney Tubules, Proximal drug effects, Kidney Tubules, Proximal metabolism, Metallothionein metabolism
- Abstract
Metallothionein (MT) is an intracellular metal-binding, cysteine-rich protein, and is a potent antioxidant that protects cells and tissues from oxidative stress. Although the major isoforms MT-1 and -2 (MT-1/-2) are highly inducible in many tissues, the distribution and role of MT-1/-2 in diabetic nephropathy are poorly understood. In this study, diabetes was induced in adult male rats by streptozotocin, and renal tissues were stained with antibodies for MT-1/-2. MT-1/-2 expression was also evaluated in mProx24 cells, a mouse renal proximal tubular epithelial cell line, stimulated with high glucose medium and pretreated with the antioxidant vitamin E. MT-1/-2 expression was gradually and dramatically increased, mainly in the proximal tubular epithelial cells and to a lesser extent in the podocytes in diabetic rats, but was hardly observed in control rats. MT-1/-2 expression was also increased by high glucose stimulation in mProx24 cells. Because the induction of MT was suppressed by pretreatment with vitamin E, the expression of MT-1/-2 is induced, at least in part, by high glucose-induced oxidative stress. These observations suggest that MT-1/-2 is induced in renal proximal tubular epithelial cells as an antioxidant to protect the kidney from oxidative stress, and may offer a novel therapeutic target against diabetic nephropathy.
- Published
- 2011
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