Biochemistry and molecular cell biology of diabetic complications
NATURE |VOL 414|13 DECEMBER 2001|
https://www.wendangku.net/doc/717294015.html,
813
? 2001 Macmillan Magazines Ltd
Toxic aldehydes Increased glucose
of the main AGE-modified proteins in endothelial cells 29. Proteins involved in macromolecular endocytosis are also modified by AGEs,as the increase in endocytosis induced by hyperglycaemia is prevent-ed by overexpression of the methylglyoxal-detoxifying enzyme glyoxalase I (ref. 30). Overexpression of glyoxalase I also completely tumour necrosis factor-?, TGF-factor, granulocyte–macrophage colony-stimulating factor and platelet-derived growth factor), and expression of pro-coagulatory and pro-inflammatory molecules by endothelial cells (thrombo-modulin, tissue factor and the cell adhesion molecule VCAM-1)NATURE |VOL 414|13 DECEMBER 2001|https://www.wendangku.net/doc/717294015.html,
815
Intr a cellul a r tr a n s d uce r s
P r o t e in s
Intr a cellul a r p r o t e in g l y c a ti o n
A G E p r ecu r so r s
ROS
NF-κB
E n d o t h el i a l cell
Ma c r o p h a g e /m R N A
R N A
D N A
T r a n sc ri p ti o n f a c t o r s
T r a n sc ri p ti o n
A G E A G E ece p t o r
c t o r s in es
? 2001 Macmillan Magazines Ltd
816NATURE|VOL 414|13 DECEMBER 2001|https://www.wendangku.net/doc/717294015.html,
?2001 Macmillan Magazines Ltd
Q .
e-
e-
e-
e-
H +
H +
ATP
synthas e
UC P
l
l II
II
l V
H +
H +
H 20
C yt c
H e at
O 2
+
N
818NATURE|VOL 414|13 DECEMBER 2001|https://www.wendangku.net/doc/717294015.html,
?2001 Macmillan Magazines Ltd
during post-hyperglycaemic periods of normal glycaemia. Hyper-glycaemia-induced increases in superoxide would not only increase polyol pathway flux, AGE formation, PKC activity and hexosamine pathway flux, but might also induce mutations in mitochondrial DNA. Defective subunits of the electron-transport complexes encoded by mutated mitochondrial DNA could eventually cause increased superoxide production at physiological concentrations of glucose, with resulting continued activation of the four pathways despite the absence of hyperglycaemia.
The second general area concerns the genetic determinants of susceptibility to both microvascular and macrovascular complica-tions. Their role in microvascular complications is supported by familial clustering of diabetic nephropathy and retinopathy. In two studies of families in which two or more siblings had type 1 diabetes, if one diabetic sibling had advanced diabetic nephropathy, the other diabetic sibling had a nephropathy risk of 83% or 72%, whereas the risk was only 17% or 22% if the index case did not have diabetic nephropathy93. The DCCT reported familial clustering of retinopa-thy with an odds ratio of 5.4 for the risk of severe retinopathy in diabetic relatives of retinopathy-positive subjects from the conventional treatment group compared with subjects with no retinopathy94. For macrovascular complications, coronary artery calcification (an indicator of subclinical atherosclerosis) also shows familial clustering, with an estimated heritability of at least 40% (ref.
95). Thus, gene-mapping studies designed to identify genes that predispose to complications, as well as the interaction of these genes with metabolic factors, are warranted.
Finally, the paradigm discussed in this review suggests that interrupting the overproduction of superoxide by the mitochondrial electron-transport chain would normalize polyol pathway flux, AGE formation, PKC activation, hexosamine pathway flux and NF-?B activation. But it might be difficult to accomplish this using conventional antioxidants, as these scavenge reactive oxygen species in a stoichiometric manner. Thus, although long-term administra-tion of a multi-antioxidant diet inhibited the development of early diabetic retinopathy in rats96, and vitamin C improved endothelium-dependent vasodilation in diabetic patients97, low-dose vitamin E failed to alter the risk of cardiovascular and renal disease in patients with diabetes98. New, low-molecular-mass compounds that act as SOD or catalase mimetics have the theoretical advantage of scavenging reactive oxygen species continuously by acting as catalysts with efficiencies approaching those of the native enzymes99. Such compounds normalize diabetes-induced inhibition of aortic prosta-cyclin synthetase in animals (M. B. et al., unpublished results), and significantly improve diabetes-induced decreases in endoneurial blood flow and motor nerve conduction velocity100. These and other agents discovered using high-throughput chemical and biological methods might have unique clinical efficacy in preventing the development and progression of diabetic complications.s 1.The Diabetes Control and Complications Trial Research Group. The effect of intensive treatment of
diabetes on the development and progression of long-term complications in insulin-dependent
diabetes mellitus. N. Engl. J. Med.329,977–986 (1993).
https://www.wendangku.net/doc/717294015.html, Prospective Diabetes Study (UKPDS) Group. Intensive blood-glucose control with
sulphonylureas or insulin compared with conventional treatment and risk of complications in
patients with type 2 diabetes (UKPDS 33). Lancet352,837–853 (1998).
3.Wei, M., Gaskill, S. P., Haffner, S. M. & Stern, M. P. Effects of diabetes and level of glycemia on all-cause
and cardiovascular mortality. The San Antonio Heart Study. Diabetes Care7,1167–1172 (1998).
4.Ebara, T. et al.Delayed catabolism of apoB-48 lipoproteins due to decreased heparan sulfate
proteoglycan production in diabetic mice. J. Clin. Invest.105,1807–1818 (2000).
5.Ginsberg, H. N. Insulin resistance and cardiovascular disease. J. Clin. Invest.106,453–458 (2000).
6.Lusis, A. J. Atherosclerosis. Nature407,233–241 (2000).
7.Hsueh, W. A. & Law, R. E. Cardiovascular risk continuum: implications of insulin resistance and
diabetes. Am. J. Med.105,4S–14S (1998).
8.Jiang, Z. Y. et al.Characterization of selective resistance to insulin signaling in the vasculature of obese
Zucker (fa/fa) rats. J. Clin. Invest.104,447–457 (1999).
9.Williams, S. B. et al.Acute hyperglycemia attenuates endothelium-dependent vasodilation in
humans in vivo. Circulation97,1695–1701 (1998).
10.Du, X. L. et al.Hyperglycemia-induced mitochondrial superoxide overproduction activates the
hexosamine pathway and induces plasminogen activator inhibitor-1 expression by increasing Sp1
glycosylation. Proc. Natl Acad. Sci. USA97,12222–12226 (2000).
11.Temelkova-Kurktschiev, T. S. et al.Postchallenge plasma glucose and glycemic spikes are more
strongly associated with atherosclerosis than fasting glucose or HbA1c levels. Diabetes Care12, 1830–1834 (2000).
12.Wilson, D. K., Bohren, K. M., Gabbay, K. H. & Quiocho, F. A. An unlikely sugar substrate site in the
1.65 A structure of the human aldose reductase holoenzyme implicated in diabetic complications.
Science257,81–84 (1992).
13.Xia, P., Kramer, R. M. & King, G. L. Identification of the mechanism for the inhibition of Na,K-
adenosine triphosphatase bv hyperglycemia involving activation of protein kinase C and cytosolic phospholipase A2. J. Clin. Invest.96,733–740 (1995).
14.Williamson, J. R. et al.Hyperglycemic pseudohypoxia and diabetic complications. Diabetes42,
801–813 (1993).
15.Garcia Soriano, F. et al.Diabetic endothelial dysfunction: the role of poly(ADP-ribose) polymerase
activation. Nature Med.7,108–113 (2001).
16.Lee, A. Y. & Chung, S. S. Contributions of polyol pathway to oxidative stress in diabetic cataract.
FASEB J.13,23–30 (1999).
17.Engerman, R. L., Kern, T. S. & Larson, M. E. Nerve conduction and aldose reductase inhibition
during 5 years of diabetes or galactosaemia in dogs. Diabetologia37,141–144 (1994).
18.Sorbinil Retinopathy Trial Research Group. A randomized trial of sorbinil, an aldose reductase
inhibitor, in diabetic retinopathy. Arch. Ophthalmol.108,1234–1244 (1990).
19.Greene, D. A., Arezzo, J. C. & Brown, M. B. Effect of aldose reductase inhibition on nerve conduction
and morphometry in diabetic neuropathy. Zenarestat Study Group. Neurology53,580–591 (1999).
20.Stitt, A. W. et al.Advanced glycation end products (AGEs) co-localize with AGE receptors in the
retinal vasculature of diabetic and of AGE-infused rats. Am. J. Pathol.150,523–528 (1997).
21.Horie, K. et al.Immunohistochemical colocalization of glycoxidation products and lipid
peroxidation products in diabetic renal glomerular lesions. Implication for glycoxidative stress in the pathogenesis of diabetic nephropathy. J. Clin. Invest.100,2995–2999 (1997).
22.Degenhardt, T. P., Thorpe, S. R. & Baynes, J. W. Chemical modification of proteins by methylglyoxal.
Cell Mol. Biol.44,1139–1145 (1998).
23.Wells-Knecht, K. J. et al.Mechanism of autoxidative glycosylation: identification of glyoxal and
arabinose as intermediates in the autoxidative modification of proteins by glucose. Biochemistry34, 3702–3709 (1995).
24.Thornalley, P. J. The glyoxalase system: new developments towards functional characterization of a
metabolic pathway fundamental to biological life. Biochem J.269,1–11 (1990).
25.Suzuki, K. et al.Overexpression of aldehyde reductase protects PC12 cells from the cytotoxicity of
methylglyoxal or 3-deoxyglucosone. J. Biochem.123,353–357 (1998).
26.Soulis-Liparota T., Cooper, M., Papazoglou, D., Clarke, B. & Jerums, G. Retardation by
aminoguanidine of development of albuminuria, mesangial expansion, and tissue fluorescence in streptozocin-induced diabetic rat. Diabetes40,1328–1334 (1991).
27.Nakamura, S. et al.Progression of nephropathy in spontaneous diabetic rats is prevented by OPB-
9195, a novel inhibitor of advanced glycation. Diabetes46,895–899 (1997).
28.Hammes, H-P. et al.Aminoguanidine treatment inhibits the development of experimental diabetic
retinopathy. Proc. Natl Acad. Sci. USA88,11555–11559 (1991).
29.Giardino, I., Edelstein, D. & Brownlee, M. Nonenzymatic glycosylation in vitro and in bovine
endothelial cells alters basic fibroblast growth factor activity. A model for intracellular glycosylation in diabetes. J. Clin. Invest.94,110–117 (1994).
30.Shinohara, M. et al.Overexpression of glyoxalase-I in bovine endothelial cells inhibits intracellular
advanced glycation endproduct formation and prevents hyperglycemia-induced increases in
macromolecular endocytosis. J. Clin. Invest.101,1142–1147 (1998).
31.Maisonpierre, P. C. et al.Angiopoietin-2, a natural antagonist for Tie2 that disrupts in vivo
angiogenesis. Science277,55–60 (1997).
32.Tanaka, S., Avigad, G., Brodsky, B. & Eikenberry, E. F. Glycation induces expansion of the molecular
packing of collagen. J. Mol. Biol.203,495–505 (1988).
33.Huijberts, M. S. P. et al.Aminoguanidine treatment increases elasticity and decreases fluid filtration
of large arteries from diabetic rats. J. Clin. Invest.92,1407–1411 (1993).
34.Tsilbary, E. C. et al.The effect of nonenzymatic glucosylation the binding of the main noncollagenous
NC1 domain to type IV collagen. J. Biol. Chem.263,4302–4308 (1990).
35.Charonis, A. S. et https://www.wendangku.net/doc/717294015.html,minin alterations after in vitro nonenzymatic glucosylation. Diabetes39,
807–814 (1988).
36.Haitoglou, C. S., Tsilibary, E. C., Brownlee, M. & Charonis, A. S. Altered cellular interactions between
endothelial cells and nonenzymatically glucosylated laminin/type IV collagen. J. Biol. Chem.267, 12404–12407 (1992).
37.Federoff, H. J., Lawrence, D. & Brownlee, M. Nonenzymatic glycosylation of laminin and the laminin
peptide CIKV AVS inhibits neurite outgrowth. Diabetes42,509–513 (1993).
38.Li, Y. M. et al.Molecular identity and cellular distribution of advanced glycation endproduct
receptors: relationship of p60 to OST-48 and p90 to 80K-H membrane proteins. Proc. Natl Acad. Sci.
USA93,11047–11052 (1996).
39.Smedsrod, B. et al.Advanced glycation end products are eliminated by scavenger-receptor-mediated
endocytosis in hepatic sinusoidal kupffer and endothelial cells. Biochem J.322,567–573 (1997). 40.Vlassara, H. et al.Identification of galectin-3 as a high-affinity binding protein for advanced glycation
end products (AGE): a new member of the AGE-receptor complex. Mol. Med.1,634–646 (1995). 41.Neeper, M. et al.Cloning and expression of RAGE: a cell surface receptor for advanced glycosylation
end products of proteins. J. Biol. Chem.267,14998–15004 (1992).
42.Vlassara, H. et al.Cachectin/TNF and IL-1 induced by glucose-modified proteins: role in normal
tissue remodeling. Science240,1546–1548 (1988).
43.Kirstein, M., Aston, C., Hintz, R. & Vlassara, H. Receptor-specific induction of insulin-like growth
factor I in human monocytes by advanced glycosylation end product-modified proteins. J. Clin.
Invest.90,439–446 (1992).
44.Abordo, E. A., Westwood, M. E. & Thornalley, P. J. Synthesis and secretion of macrophage colony
stimulating factor by mature human monocytes and human monocytic THP-1 cells induced by human serum albumin derivatives modified with methylglyoxal and glucose-derived advanced glycation endproducts. Immunol. Lett.53,7–13 (1996).
45.Skolnik, E. Y. et al.Human and rat mesangial cell receptors for glucose-modified proteins: potential
role in kidney tissue remodelling and diabetic nephropathy. J. Exp. Med.174,931–939 (1991).
46.Doi, T. et al.Receptor specific increase in extracellular matrix productions in mouse mesangial cells
by advanced glycosylation end products is mediated via platelet derived growth factor. Proc. Natl Acad. Sci. USA89,2873–2877 (1992).
NATURE|VOL 414|13 DECEMBER 2001|https://www.wendangku.net/doc/717294015.html,819
?2001 Macmillan Magazines Ltd
47.Schmidt, A. M. et al.Advanced glycation endproducts interacting with their endothelial receptor
induce expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured human endothelial cells and in mice: a potential mechanism for the accelerated vasculopathy of diabetes. J. Clin. Invest.
96,1395–1403 (1995).
48.Lu, M. et al.Advanced glycation end products increase retinal vascular endothelial growth factor
expression. J. Clin. Invest.101,1219–1224 (1998).
49.Park, L. et al.Suppression of accelerated diabetic atherosclerosis by the soluble receptor for advanced
glycation endproducts. Nature Med.4,1025–1031 (1998).
50.Yan, S. D. et al.Enhanced cellular oxidant stress by the interaction of advanced glycation end products
with their receptors/binding proteins. J. Biol. Chem.269,9889–9897 (1994).
https://www.wendangku.net/doc/717294015.html,nder, H. M. et al.Activation of the receptor for advanced glycation end products triggers a
p21(ras)-dependent mitogen-activated protein kinase pathway regulated by oxidant stress. J. Biol.
Chem.272,17810–17814 (1997).
52.Yamagishi, S. et al.Advanced glycation endproducts inhibit prostacyclin production and induce
plasminogen activator inhibitor-1 in human microvascular endothelial cells. Diabetologia41,
1435–1441 (1998).
53.Tsuji, H. et al.Ribozyme targeting of receptor for advanced glycation end products in mouse
mesangial cells. Biochem. Biophys. Res. Commun.245,583–588 (1998).
54.Koya, D. & King, G. L. Protein kinase C activation and the development of diabetic complications.
Diabetes47,859–866 (1998).
55.Xia, P. et al.Characterization of the mechanism for the chronic activation of diacylglycerol-protein
kinase C pathway in diabetes and hypergalactosemia. Diabetes43,1122–1129 (1994).
56.Koya, D. et al.Characterization of protein kinase C beta isoform activation on the gene expression of
transforming growth factor-beta, extracellular matrix components, and prostanoids in the glomeruli of diabetic rats. J. Clin. Invest.100,115–126 (1997).
57.Portilla, D. et al.Etomoxir -induced PPARalpha-modulated enzymes protect during acute renal
failure. Am. J. Physiol. Renal Physiol.278,F667–F675 (2000).
58.Keogh, R. J., Dunlop, M. E. & Larkins R.. G. Effect of inhibition of aldose reductase on glucose flux,
diacylglycerol formation, protein kinase C, and phospholipase A2 activation. Metabolism46, 41–47 (1997).
59.Ishii, H. et al.Amelioration of vascular dysfunctions in diabetic rats by an oral PKC beta inhibitor.
Science272,728–731 (1996).
60.Craven, P. A., Studer, R. K. & DeRubertis, F. R. Impaired nitric oxide-dependent cyclic guanosine
monophosphate generation in glomeruli from diabetic rats. Evidence for protein kinase C-mediated suppression of the cholinergic response. J. Clin. Invest.93,311–320 (1994).
61.Ganz, M. B. & Seftel, A. Glucose-induced changes in protein kinase C and nitric oxide are prevented
by vitamin E. Am. J. Physiol.278,E146–E152 (2000).
62.Kuboki, K. et al.Regulation of endothelial constitutive nitric oxide synthase gene expression in
endothelial cells and in vivo a specific vascular action of insulin. Circulation101,676–681 (2000). 63.Glogowski, E. A., Tsiani, E., Zhou, X., Fantus, I. G. & Whiteside, C. High glucose alters the response of
mesangial cell protein kinase C isoforms to endothelin-1. Kidney Int.55,486–499 (1999).
64.Hempel, A. et al.High glucose concentrations increase endothelial cell permeability via activation of
protein kinase C alpha. Circ. Res.81,363–371 (1997).
65.Williams, B., Gallacher, B., Patel, H. & Orme, C. Glucose-induced protein kinase C activation
regulates vascular permeability factor mRNA expression and peptide production by human vascular smooth muscle cells in vitro. Diabetes46,1497–1503 (1997).
66.Studer, R. K., Craven, P. A. & DeRubertis, F. R. Role for protein kinase C in the mediation of
increased fibronectin accumulation by mesangial cells grown in high-glucose medium. Diabetes42, 118–126 (1993).
67.Koya, D. et al.Characterization of protein kinase C beta isoform activation on the gene expression of
transforming growth factor-beta, extracellular matrix components, and prostanoids in the glomeruli of diabetic rats. J. Clin. Invest.100,115–126 (1997).
68.Craven, P. A., Studer, R. K., Felder, J., Phillips, S. & DeRubertis, F. R. Nitric oxide inhibition of
transforming growth factor-beta and collagen synthesis in mesangial cells. Diabetes46,671–681 (1997).
69.Phillips, S. L., DeRubertis, F. R. & Craven, P. A. Regulation of the laminin C1 promoter in cultured
mesangial cells. Diabetes48,2083–2089 (1999).
70.Feener, E. P. et al.Role of protein kinase C in glucose- and angiotensin II-induced plasminogen
activator inhibitor expression. Contrib. Nephrol.118,180–187 (1996).
71.Pieper, G. M. & Riaz-ul-Haq, J. Activation of nuclear factor-kappaB in cultured endothelial cells
by increased glucose concentration: prevention by calphostin C. Cardiovasc. Pharmacol.30, 528–532 (1997).
72.Yerneni, K. K., Bai, W., Khan, B. V., Medford, R. M. & Natarajan, R. Hyperglycemia-induced
activation of nuclear transcription factor kappaB in vascular smooth muscle cells. Diabetes48,
855–864 (1999).
73.Koya, D. et al.Amelioration of accelerated diabetic mesangial expansion by treatment with a PKC beta
inhibitor in diabetic db/db mice, a rodent model for type 2 diabetes. FASEB J.14,439–447 (2000). 74.Kolm-Litty, V., Sauer, U., Nerlich, A., Lehmann, R. & Schleicher, E. D. High glucose-induced
transforming growth factor beta1 production is mediated by the hexosamine pathway in porcine glomerular mesangial cells. J. Clin. Invest.101,160–169 (1998).75.Marshall, S., Bacote, V. & Traxinger, R. R. Discovery of a metabolic pathway mediating glucose-
induced desensitization of the glucose transport system. Role of hexosamine biosynthesis in the induction of insulin resistance. J. Biol. Chem.266,4706–4712 (1991).
76.Hawkins, M. et al.Role of the glucosamine pathway in fat-induced insulin resistance. J. Clin. Invest.
99,2173–2182 (1997).
77.Chen, Y. Q. et al.Sp1 sites mediate activation of the plasminogen activator inhibitor-1 promoter by
glucose in vascular smooth muscle cells. J. Biol. Chem.273,8225–8231 (1998).
78.Goldberg, H. J., Scholey, J. & Fantus, I. G. Glucosamine activates the plasminogen activator inhibitor
1 gene promoter through Sp1 DNA binding sites in glomerular mesangial cells. Diabetes49,
863–871 (2000).
79.Kadonaga, J. T., Courey, A. J., Ladika, J. & Tjian, R. Distinct regions of Sp1 modulate DNA binding
and transcriptional activation. Science242,1566–1570 (1988).
80.Haltiwanger, R. S., Grove, K. & Philipsberg, G. A. Modulation of O-linked N-acetylglucosamine levels
on nuclear and cytoplasmic proteins in vivo using the peptide O-GlcNAc-beta-N-
acetylglucosaminidase inhibitor O-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino-N-
phenylcarbamate. J. Biol. Chem.273,3611–3617 (1998).
81.Hart, G. W. Dynamic O-linked glycosylation of nuclear and cytoskeletal proteins Annu. Rev. Biochem.
66,315–335 (1997).
82.Du, X. D. et al.Hyperglycemia inhibits endothelial nitric oxide synthase activity by posttranslational
modification at the AKT site. J. Clin. Invest.(in the press).
83.Lee, A. Y., Chung, S. K. & Chung, S. S. Demonstration that polyol accumulation is responsible for
diabetic cataract by the use of transgenic mice expressing the aldose reductase gene in the lens. Proc.
Natl Acad. Sci. USA92,2780–2784 (1995).
84.Nishikawa, T. et al.Normalizing mitochondrial superoxide production blocks three pathways of
hyperglycaemic damage. Nature404,787–790 (2000).
85.Giugliano, D., Ceriello, A. & Paolisso, G. Oxidative stress and diabetic vascular complications.
Diabetes Care19,257–267 (1996).
86.Giardino, I., Edelstein, D. & Brownlee, M.BCL-2 expression or antioxidants prevent hyperglycemia-
induced formation of intracellular advanced glycation endproducts in bovine endothelial cells. J.
Clin. Invest.97,1422–1428 (1996).
87.Korshunov, S. S., Skulachev, V. P. & Starkov, A. A. High protonic potential actuates a mechanism of
production of reactive oxygen species in mitochondria. FEBS Lett.416,15–18 (1997).
88.Craven, R. P., Phillip, S. L., Melhem, M. F., Liachenko, J. & De Rubertis, F. R. Overexpression of Mn2+
superoxide dismutase suppresses increases in collagen accumulation induced by culture in
measangial cells in high media glucose. Metabolism(in the press).
89.Y amagishi, S. I., Edelstein, D., Du, X. L. & Brownlee, M. Hyperglycemia potentiates collagen-induced
platelet activation through mitochondrial superoxide overproduction. Diabetes50,1491–1494 (2001).
90.Craven, P. A., Melham, M. F., Phillip, S. L. & DeRubertis, F. R. Overexpression of Cu2+/Zn2+
superoxide dismutase protects against early diabetic glomerular injury in transgenic mice. Diabetes 50,2114–2125 (2001).
91.Engerman, R. L. & Kern, T. S. Progression of incipient diabetic retinopathy during good glycemic
control. Diabetes36,808–812 (1987).
92.The Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and
Complications Research Group. Retinopathy and nephropathy in patients with type 1 diabetes four years after a trial of intensive therapy. N. Engl. J. Med.342,381–389 (2000).
93.Quinn, M., Angelico, M. C., Warram, J. H. & Krolewski, A. S. Familial factors determine the
development of diabetic nephropathy in patients with IDDM. Diabetologia39,940–945 (1996). 94.The Diabetes Control and Complications Trial Research Group. Clustering of long-term
complications in families with diabetes in the diabetes control and complications trial. Diabetes46, 1829–1839 (1997).
95.Wagenknecht, L. E. et al.Familial aggregation of coronary artery calcium in families with type 2
diabetes. Diabetes50,861–866 (2001).
96.Kowluru, R. A., Tang, J. & Kern, T. S. Abnormalities of retinal metabolism in diabetes and
experimental galactosemia. VII. Effect of long-term administration of antioxidants on the
development of retinopathy. Diabetes50,1938–1942 (2001).
97.Ting, H. H. et al.Vitamin C improves endothelium-dependent vasodilation in patients with non-
insulin-dependent diabetes mellitus. J. Clin. Invest.97,22–28 (1996).
98.Heart Outcomes Prevention Evaluation Study Investigators. Effects of ramipril on cardiovascular and
microvascular outcomes in people with diabetes mellitus: results of the HOPE study and MICRO-HOPE substudy. Lancet355,253–259 (2000).
99.Salvemini, D. et al.A nonpeptidyl mimic of superoxide dismutase with therapeutic activity in rats.
Science286,304–306 (1999).
100.Coppey, L. J. et al.Brit. J. Pharmacol. 134, 21–29 (2001).
Acknowledgements
This work was supported by grants from NIH, Juvenile Diabetes Research Foundation and American Diabetes Association. Owing to space limitations, a comprehensive list of reference citations could not be included. I apologize to those colleagues whose work is not specifically referenced, and gratefully acknowledge their contributions to the field.
820NATURE|VOL 414|13 DECEMBER 2001|https://www.wendangku.net/doc/717294015.html,
?2001 Macmillan Magazines Ltd