Overexpression of Cu2+/Zn2+ Superoxide Dismutase Protects Against Early Diabetic Glomerular Injury in Transgenic Mice

• Published in: Diabetes (New York, N.Y.) Vol. 50; no. 9; pp. 2114 - 2125
• Main Authors: CRAVEN, Patricia A, MELHEM, Mona F, PHILLIPS, Stephen L, DERUBERTISL, Frederick R
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01-09-2001
• Subjects: Aconitate Hydratase - metabolism; Animals; Associated diseases and complications; Biological and medical sciences; Breath tests; Cells, Cultured; Collagen; Collagen - antagonists & inhibitors; Creatinine - blood; Diabetes; Diabetes Mellitus, Experimental - complications; Diabetes Mellitus, Experimental - pathology; Diabetes. Impaired glucose tolerance; Diabetic Nephropathies - etiology; Diabetic Nephropathies - prevention & control; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Enzymes; Glomerular Mesangium - drug effects; Glomerular Mesangium - metabolism; Glomerular Mesangium - pathology; Glucose; Glucose - pharmacology; Growth factors; Hemoglobin; Humans; Kidney Cortex - enzymology; Kidney Glomerulus - drug effects; Lipid peroxidation; Lipids; Medical sciences; Mice; Mice, Inbred C57BL; Mice, Transgenic - genetics; Oxidation; Oxidation-Reduction - drug effects; Oxidative stress; Pathogenesis; Protein synthesis; Reference Values; Superoxide Dismutase - genetics; Superoxide Dismutase - metabolism; Transgenic animals; Endocrinopathy; Kidney disease; Urinary system disease; Enzyme; Mesangial cell; Diabetes mellitus; Rodentia; Transgenic animal; Gene overexpression; Superoxide dismutase; In vitro; Kidney; Renal glomerulus; Vertebrata; Mammalia; Nephropathy; Urinary system; Mouse; Complication; Oxidoreductases; Protection
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/diabetes.50.9.2114

Overexpression of Cu 2+ /Zn 2+ Superoxide Dismutase Protects Against Early Diabetic Glomerular Injury in Transgenic Mice
Patricia A. Craven 1 ,
Mona F. Melhem 2 ,
Stephen L. Phillips 3 and
Frederick R. DeRubertis 1
1 Medicine
2 Pathology, and
3 Molecular Genetics and Biochemistry, VA Medical Center and University of Pittsburgh, Pittsburgh, Pennsylvania
Abstract
Ex vivo and in vitro observations implicate superoxide as a mediator of cell injury in diabetes, but in vivo evidence is lacking.
In the current studies, parameters of glomerular injury were examined in hemizygous nondiabetic transgenic mice (SOD) and
streptozotocin-diabetic (D) transgenic mice (D-SOD), which overexpress human cytoplasmic Cu 2+ /Zn 2+ superoxide dismutase (SOD-1), and in corresponding wild-type littermates (WT, D-WT) after 4 months of diabetes. In both SOD
and D-SOD mice, renal cortical SOD-1 activity was twofold higher than values in the WT mice; blood glucose and glycosylated
hemoglobin (GHb) levels did not differ in the two diabetic groups. Urinary albumin excretion, fractional albumin clearance,
urinary transforming growth factor-β (TGF-β) excretion, glomerular volume, glomerular content of immunoreactive TGF-β, and
collagen α1 (IV) and renal cortical malondialdehyde (MDA) levels were significantly higher in D-WT mice compared with corresponding
values in D-SOD mice. Glomerular volume, glomerular content of TGF-β and collagen IV, renal cortical MDA, and urinary excretion
of TGF-β in D-SOD mice did not differ significantly from corresponding values in either the nondiabetic SOD or WT mice. In
separate groups of mice studied after 8 months of diabetes, mesangial matrix area, calculated as a fraction of total glomerular
tuft area, and plasma creatinine were significantly higher in D-WT but not in D-SOD mice, compared with corresponding values
in the nondiabetic mice. In vitro infection of mesangial cells (MC) with a recombinant adenovirus encoding human SOD-1 increased
SOD-1 activity threefold over control cells and prevented the reduction of aconitase activity, an index of cellular superoxide,
and the increase in collagen synthesis that otherwise occurred in control MC in response to culture with 300 or 500 mg/dl
glucose. Thus, increases in cellular SOD-1 activity attenuate diabetic renal injury in vivo and also prevent stimulation of
MC matrix protein synthesis induced in vitro by high glucose.
Footnotes
Address correspondence and reprint requests to Frederick R. DeRubertis, MD, VA Medical Center, University Drive C, Pittsburgh,
PA 15240. E-mail frederick.derubertis{at}med.va.gov .
Received for publication 27 July 2000 and accepted in revised form 25 May 2001.
ACE, angiotensin-converting enzyme; C IN , inulin clearance; CMV, cytomegalovirus; ELISA, enzyme-linked immunosorbent assay; GHb, glycosylated hemoglobin; MC, mesangial
cells; MDA, malondialdehyde; SOD-1, cytoplasmic Cu 2+ /Zn 2+ superoxide dismutase; STZ, streptozotocin; TGF-β, transforming growth factor-β.