title: Expression of angiotensinogen and receptors for angiotensin and prorenin in the monkey and human substantia nigra: an intracellular renin-angiotensin system in the nigra.
abstract: We have previously obtained in rodents a considerable amount of data suggesting a major role for the brain renin-angiotensin system (RAS) in dopaminergic neuron degeneration and potentially in Parkinson's disease. However, the presence of a local RAS has not been demonstrated in the monkey or the human substantia nigra compacta (SNc). The present study demonstrates the presence of major RAS components in dopaminergic neurons, astrocytes and microglia in both the monkey and the human SNc. Angiotensin type 1 and 2 and renin-prorenin receptors were located at the surface of dopaminergic neurons and glial cells, as expected for a tissular RAS. However, angiotensinogen and receptors for angiotensin and renin-prorenin were also observed at the cytoplasm and nuclear level, which suggests the presence of an intracrine or intracellular RAS in monkey and human SNc. Although astrocytes and microglia were labeled for angiotensin and prorenin receptors in the normal SNc, most glial cells appeared less immunoreactive than the dopaminergic neurons. However, our previous studies in rodent models of PD and studies in other animal models of brain diseases suggest that the RAS activity is significantly upregulated in glial cells in pathological conditions. The present results together with our previous findings in rodents suggest a major role for the nigral RAS in the normal functioning of the dopaminergic neurons, and in the progression of the dopaminergic degeneration.
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Department of Morphological Sciences, Faculty of Medicine, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Garrido-Gil
authors.forename: Rita
authors.initials: R
authors.lastname: Valenzuela
authors.forename: Begoña
authors.initials: B
authors.lastname: Villar-Cheda
authors.forename: Jose L
authors.initials: JL
authors.lastname: Lanciego
authors.forename: Jose L
authors.initials: JL
authors.lastname: Labandeira-Garcia
mesh_terms: D000328:Adult; D000808:Angiotensinogen / Q000032:analysis*; D000818:Animals; D001253:Astrocytes / Q000737:chemistry; D001344:Autopsy; D059290:Dopaminergic Neurons / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D006801:Humans; D008252:Macaca fascicularis; D008297:Male; D017628:Microglia / Q000737:chemistry; D018613:Microscopy, Confocal; D044140:Receptor, Angiotensin, Type 1 / Q000032:analysis*; D044139:Receptor, Angiotensin, Type 2 / Q000032:analysis*; D011956:Receptors, Cell Surface / Q000032:analysis*; D012084:Renin-Angiotensin System; D013378:Substantia Nigra / Q000737:chemistry* / Q000166:cytology; D025262:Vacuolar Proton-Translocating ATPases / Q000032:analysis*; D000093342:Prorenin Receptor
chemical_list: C458319:ATP6AP2 protein, human; D044140:Receptor, Angiotensin, Type 1; D044139:Receptor, Angiotensin, Type 2; D011956:Receptors, Cell Surface; D000808:Angiotensinogen; D025262:Vacuolar Proton-Translocating ATPases; D000093342:Prorenin Receptor