Manganese and Vanadium Co-Exposure Induces Severe Neurotoxicity in the Olfactory System: Relevance to Metal-Induced Parkinsonism

• Published in: International journal of molecular sciences Vol. 25; no. 10; p. 5285
• Main Authors: Ngwa, Hilary Afeseh, Bargues-Carot, Alejandra, Jin, Huajun, Anantharam, Vellareddy, Kanthasamy, Arthi, Kanthasamy, Anumantha G
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.05.2024
• Subjects: 3,4-Dihydroxyphenylacetic Acid - metabolism; Aerosols; Aldehydes - metabolism; alpha-synuclein; alpha-Synuclein - metabolism; Animals; Chlorides - metabolism; Chlorides - toxicity; Comparative analysis; Disease; Disease Models, Animal; Dopamine - metabolism; Dust; Females; Heavy metals; Kinases; Male; manganese; Manganese - toxicity; Manganese Compounds; Manufacturing; metal mixtures; Mice; Mice, Inbred C57BL; Nervous system; Neurotoxicity; Olfactory Bulb - drug effects; Olfactory Bulb - metabolism; Olfactory Bulb - pathology; Oxidative stress; Oxidative Stress - drug effects; Parkinson's disease; Parkinsonian Disorders - chemically induced; Parkinsonian Disorders - metabolism; Parkinsonism; Pathogenesis; Resveratrol; Substantia Nigra - drug effects; Substantia Nigra - metabolism; Substantia Nigra - pathology; Tyrosine; Tyrosine 3-Monooxygenase - metabolism; Vanadium; Vanadium - toxicity; Vanadium Compounds; Parkinsonism; vanadium; metal mixtures; neurotoxicity; alpha-synuclein; manganese
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms25105285

Chronic environmental exposure to toxic heavy metals, which often occurs as a mixture through occupational and industrial sources, has been implicated in various neurological disorders, including Parkinsonism. Vanadium pentoxide (V O ) typically presents along with manganese (Mn), especially in welding rods and high-capacity batteries, including electric vehicle batteries; however, the neurotoxic effects of vanadium (V) and Mn co-exposure are largely unknown. In this study, we investigated the neurotoxic impact of MnCl , V O and MnCl -V O co-exposure in an animal model. C57BL/6 mice were intranasally administered either de-ionized water (vehicle), MnCl (252 µg) alone, V O (182 µg) alone, or a mixture of MnCl (252 µg) and V O (182 µg) three times a week for up to one month. Following exposure, we performed behavioral, neurochemical, and histological studies. Our results revealed dramatic decreases in olfactory bulb (OB) weight and levels of tyrosine hydroxylase, dopamine, and 3,4-dihydroxyphenylacetic acid in the treatment groups compared to the control group, with the Mn/V co-treatment group producing the most significant changes. Interestingly, increased levels of α-synuclein expression were observed in the substantia nigra (SN) of treated animals. Additionally, treatment groups exhibited locomotor deficits and olfactory dysfunction, with the co-treatment group producing the most severe deficits. The treatment groups exhibited increased levels of the oxidative stress marker 4-hydroxynonenal in the striatum and SN, as well as the upregulation of the pro-apoptotic protein PKCδ and accumulation of glomerular astroglia in the OB. The co-exposure of animals to Mn/V resulted in higher levels of these metals compared to other treatment groups. Taken together, our results suggest that co-exposure to Mn/V can adversely affect the olfactory and nigral systems. These results highlight the possible role of environmental metal mixtures in the etiology of Parkinsonism.