Aging-related changes in the nigral angiotensin system enhances proinflammatory and pro-oxidative markers and 6-OHDA-induced dopaminergic degeneration.
An age-related proinflammatory, pro-oxidant state in the nigra may increase the vulnerability of dopaminergic neurons to additional damage. Angiotensin II, via type 1 (AT1) receptors, is one of the most important known inflammation and oxidative stress inducers. However, it is not known if there are age-related changes in the nigral angiotensin system. In aged rats, we observed increased activation of the nicotinamide adenine dinucleotide phosphate-oxidase (NADPH oxidase) complex and increased levels of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α, which indicate pro-oxidative, proinflammatory state in the nigra. We also observed enhanced 6-hydroxydopamine (6-OHDA)-induced dopaminergic cell death in aged rats. This is associated with increased expression of AT1 receptors and decreased expression of AT2 receptors in aged rats, and is reduced by treatment with the AT1 antagonist candesartan. The present results indicate that brain angiotensin is involved in changes that may increase the risk of Parkinson's disease with aging. Furthermore, the results suggest that manipulation of the brain angiotensin system may constitute an effective neuroprotective strategy against aging-related risk of dopaminergic degeneration.
Villar-Cheda
Begoña
B
Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Faculty of Medicine, University of Santiago de Compostela, Santiago de Compostela, Spain.
Valenzuela
Rita
R
Rodriguez-Perez
Ana I
AI
Guerra
Maria J
MJ
Labandeira-Garcia
Jose L
JL
D000375:Aging / Q000378:metabolism / Q000473:pathology* / Q000502:physiology*; D000804:Angiotensin II / Q000502:physiology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D001713:Biphenyl Compounds; D059290:Dopaminergic Neurons / Q000378:metabolism / Q000473:pathology*; D018836:Inflammation Mediators / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism*; D008297:Male; D058990:Molecular Targeted Therapy; D019255:NADPH Oxidases / Q000378:metabolism*; D009410:Nerve Degeneration; D018384:Oxidative Stress; D016627:Oxidopamine / Q000494:pharmacology*; D010300:Parkinson Disease / Q000209:etiology / Q000628:therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D044140:Receptor, Angiotensin, Type 1 / Q000502:physiology; D013378:Substantia Nigra / Q000378:metabolism* / Q000473:pathology; D013777:Tetrazoles / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D047228:Angiotensin II Type 1 Receptor Blockers; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D017382:Reactive Oxygen Species; D044140:Receptor, Angiotensin, Type 1; D013777:Tetrazoles; D014409:Tumor Necrosis Factor-alpha; D000804:Angiotensin II; D016627:Oxidopamine; D019255:NADPH Oxidases; C081643:candesartan