A modest decrease in endothelial NOS in mice comparable to that associated with
human NOS3 variants exacerbates diabetic nephropathy.
Authors Wang CH, Li F, Hiller S, Kim HS, Maeda N, Smithies O, Takahashi N
Submitted By Nobuyuki Takahashi on 1/24/2011
Status Published
Journal Proceedings of the National Academy of Sciences of the United States of America
Year 2011
Date Published 2/1/2011
Volume : Pages 108 : 2070 - 5
PubMed Reference 21245338
Abstract Polymorphisms in the human endothelial nitric oxide synthase (eNOS) gene (NOS3)
have been associated with advanced nephropathy in diabetic patients and with
decreased expression in tissue culture. However, direct proof that modest
genetic decreases in eNOS expression worsen diabetic nephropathy is lacking. To
investigate this effect, we took advantage of the hybrid vigor and genetic
uniformity of the F1 progeny (eNOS(+/+), eNOS(+/-), or eNOS(-/-) with or without
diabetes) of a cross between heterozygous 129S6/SvEvTac eNOS(+/-) inbred females
and heterozygous C57BL/6J eNOS(+/-) inbred males carrying the dominant Akita
diabetogenic mutation Ins2(C96Y/+). Whereas all C57BL/6J inbred eNOS(-/-) and
eNOS(+/-) diabetic mice died before 5 mo, almost half of the F1 hybrid eNOS(-/-)
and eNOS(+/-) diabetic mice lived until killed at 7 mo. Heterozygous eNOS(+/-)
diabetic mice expressed ~35% eNOS mRNA in the kidney and ~25% glomerular eNOS
protein relative to their eNOS(+/+) diabetic littermates. These decreases in
eNOS elevated blood pressure (BP) but not blood glucose. Urinary albumin
excretion, mesangial expansion, glomerulosclerosis, mesangiolysis, and
glomerular filtration rate increased in the order: eNOS(+/+) Akita < eNOS(+/-)
Akita < eNOS(-/-) Akita, independently of BP. Glomerular basement membrane
thickening depended on increased BP. Renal expression of tissue factor and other
inflammatory factors increased with the nephropathy; Nos2 also increased.
Surprisingly, however, decreased eNOS expression ameliorated the increases in
oxidative stress and tubulointerstitial fibrosis caused by diabetes. Our data
demonstrate that a modest decrease in eNOS, comparable to that associated with
human NOS3 variants, is sufficient to enhance diabetic nephropathy independently
of its effects on BP.

Investigators with authorship
Nobuyo MaedaUniversity of North Carolina
Oliver SmithiesUniversity of North Carolina
Nobuyuki TakahashiTohoku University