Evidence for important role of peroxynitrite, a product of superoxide reaction with nitric oxide, in diabetic complications is emerging. Using new pharmacological agents i.e., peroxynitrite decomposition catalysts and protein nitration inhibitor, and iNOS-knockout mice, we obtained findings implicating peroxynitrite injury in toto and protein nitration in early experimental peripheral diabetic neuropathy (PDN). We found that 1) nitro- tyrosine (NT), a footprint of peroxynitrite injury, accumulates in peripheral nerve, spinal cord, and DRG neurons of streptozotocin (STZ)-diabetic and ob/ob mice;2) STZ-diabetic iNOS-deficient mice do not develop nerve conduction deficits and have less severe sensory neuropathy compared with diabetic wild-type mice;and 3) peroxynitrite decomposition catalysts and, to a lesser extent, a protein nitration inhibitor, corrected nerve conduction deficits and sensory neuropathy in mice with Type 1 and Type 2 diabetes. We also found that Type 2 diabetic patients accumulate different amounts of nitrated proteins in peripheral blood monocytes, that monocyte NT concentration is ~ 75% greater in Type 2 diabetic subjects compared with non-diabetic group, and that skin production of NO, a precursor of peroxynitrite, is reduced by pioglitazone treatment. Others showed that increased plasma NT content correlated with endothelial dysfunction and redistribution of sudomotor responses, an early sign of sympathetic nerve dysfunction, in diabetic patients. The overall objective of this proposal is to dissect the roles of peroxynitrite and protein nitration in functional and morphological changes of advanced experimental PDN, and to determine if NT levels in serum, peripheral blood monocytes, and skin can be used as biomarkers of the presence, severity, and progression of PDN in human subjects with diabetes.
The specific aims are: 1) evaluate if peroxynitrite decomposition catalyst and protein nitration inhibitor reverse functional, behavioral, and morphological changes of advanced PDN in STZ- diabetic and Akita mice;2) assess the effect of blood glucose control on accumulation and disappearance of NT in tissue-sites of PDN, skin, and circulation;and 3) determine potential values of serum, peripheral blood monocyte, and skin NT levels as biomarkers of the presence, severity, and progression of PDN in human subjects with diabetes mellitus. The findings will advance our understanding of the pathogenesis of PDN, and may provide rationale for development of new therapeutics. They may also lead to identification of a new biomarker(s) of PDN with diagnostic and prognostic value.

Public Health Relevance

Peripheral diabetic neuropathy (PDN) is the most devastating complication of diabetes mellitus, and a leading cause of foot amputation. Evidence for important role of peroxynitrite (a product of superoxide reaction with nitric oxide) in PDN is emerging and is supported by our preliminary data obtained in both diabetic mouse models and human subjects with diabetes mellitus. The overall objective of this proposal is to dissect the roles of peroxynitrite and one of its components, protein nitration, in functional and morphological changes of advanced experimental PDN, and to determine if nitrotyrosine levels in serum, peripheral blood monocytes, and skin can be used as biomarkers of the presence, severity, development and rate of progression of PDN in human subjects with diabetes.
The specific aims are: 1) evaluate if peroxynitrite decomposition catalyst or protein nitration inhibitor reverse functional, behavioral, and morphological manifestations of advanced PDN in two mouse models of Type 1 diabetes;2) assess the effect of blood glucose control on accumulation and disappearance of nitrotyrosine in tissue-sites of PDN, skin, and circulation;and 3) determine potential values of serum, peripheral blood monocyte, and skin nitrotyrosine levels as biomarkers of the presence, severity, development, and rate of progression of PDN in human subjects with diabetes mellitus. The findings will advance our understanding of the pathogenesis of PDN, and may provide rationale for development of new therapeutics. They may also lead to identification of a new biomarker(s) of PDN with diagnostic and prognostic value.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK081147-03
Application #
8243618
Study Section
Special Emphasis Panel (ZRG1-BDCN-Y (04))
Program Officer
Jones, Teresa L Z
Project Start
2010-04-01
Project End
2013-01-31
Budget Start
2012-04-01
Budget End
2013-01-31
Support Year
3
Fiscal Year
2012
Total Cost
$103,160
Indirect Cost
$14,900
Name
Lsu Pennington Biomedical Research Center
Department
None
Type
Organized Research Units
DUNS #
611012324
City
Baton Rouge
State
LA
Country
United States
Zip Code
70808
Stavniichuk, Roman; Shevalye, Hanna; Lupachyk, Sergey et al. (2014) Peroxynitrite and protein nitration in the pathogenesis of diabetic peripheral neuropathy. Diabetes Metab Res Rev 30:669-78
Lupachyk, Sergey; Watcho, Pierre; Obrosov, Alexander A et al. (2013) Endoplasmic reticulum stress contributes to prediabetic peripheral neuropathy. Exp Neurol 247:342-8
Lupachyk, Sergey; Watcho, Pierre; Stavniichuk, Roman et al. (2013) Endoplasmic reticulum stress plays a key role in the pathogenesis of diabetic peripheral neuropathy. Diabetes 62:944-52
Lupachyk, Sergey; Stavniichuk, Roman; Komissarenko, Julia I et al. (2012) Na+/H+-exchanger-1 inhibition counteracts diabetic cataract formation and retinal oxidative-nitrative stress and apoptosis. Int J Mol Med 29:989-98
Shevalye, Hanna; Lupachyk, Sergey; Watcho, Pierre et al. (2012) Prediabetic nephropathy as an early consequence of the high-calorie/high-fat diet: relation to oxidative stress. Endocrinology 153:1152-61
Stavniichuk, Roman; Shevalye, Hanna; Hirooka, Hiroko et al. (2012) Interplay of sorbitol pathway of glucose metabolism, 12/15-lipoxygenase, and mitogen-activated protein kinases in the pathogenesis of diabetic peripheral neuropathy. Biochem Pharmacol 83:932-40
Lupachyk, Sergey; Watcho, Pierre; Hasanova, Nailia et al. (2012) Triglyceride, nonesterified fatty acids, and prediabetic neuropathy: role for oxidative-nitrosative stress. Free Radic Biol Med 52:1255-63
Drel, Viktor R; Pacher, Pal; Stavniichuk, Roman et al. (2011) Poly(ADP-ribose)polymerase inhibition counteracts renal hypertrophy and multiple manifestations of peripheral neuropathy in diabetic Akita mice. Int J Mol Med 28:629-35
Lupachyk, Sergey; Shevalye, Hanna; Maksimchyk, Yury et al. (2011) PARP inhibition alleviates diabetes-induced systemic oxidative stress and neural tissue 4-hydroxynonenal adduct accumulation: correlation with peripheral nerve function. Free Radic Biol Med 50:1400-9