Cortical Astrocytes Acutely Exposed to the Monomethylarsonous Acid (MMAIII) Show Increased Pro-inflammatory Cytokines Gene Expression that is Consistent with APP and BACE-1: Over-expression.
Long-term exposure to inorganic arsenic (iAs) through drinking water has been associated with cognitive impairment in children and adults; however, the related pathogenic mechanisms have not been completely described. Increased or chronic inflammation in the brain is linked to impaired cognition and neurodegeneration; iAs induces strong inflammatory responses in several cells, but this effect has been poorly evaluated in central nervous system (CNS) cells. Because astrocytes are the most abundant cells in the CNS and play a critical role in brain homeostasis, including regulation of the inflammatory response, any functional impairment in them can be deleterious for the brain. We propose that iAs could induce cognitive impairment through inflammatory response activation in astrocytes. In the present work, rat cortical astrocytes were acutely exposed in vitro to the monomethylated metabolite of iAs (MMAIII), which accumulates in glial cells without compromising cell viability. MMAIIILD50in astrocytes was 10.52 μM, however, exposure to sub-toxic MMAIIIconcentrations (50-1000 nM) significantly increased IL-1β, IL-6, TNF-α, COX-2, and MIF-1 gene expression. These effects were consistent with amyloid precursor protein (APP) and β-secretase (BACE-1) increased gene expression, mainly for those MMAIIIconcentrations that also induced TNF-α over-expression. Other effects of MMAIIIon cortical astrocytes included increased proliferative and metabolic activity. All tested MMAIIIconcentrations led to an inhibition of intracellular lactate dehydrogenase (LDH) activity. Results suggest that MMAIIIinduces important metabolic and functional changes in astrocytes that may affect brain homeostasis and that inflammation may play a major role in cognitive impairment-related pathogenicity in As-exposed populations.
Laboratorio de Inmunotoxicologia, Facultad de Ciencias Quimicas., Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava No. 6, San Luis Potosi, 78240, SLP, Mexico. cescuder@uaslp.mx.
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http://orcid.org/0000-0002-4597-1420
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Escudero-Lourdes
Laboratorio de Inmunotoxicologia, Facultad de Ciencias Quimicas., Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava No. 6, San Luis Potosi, 78240, SLP, Mexico.
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Uresti-Rivera
Laboratorio de Inmunotoxicologia, Facultad de Ciencias Quimicas., Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava No. 6, San Luis Potosi, 78240, SLP, Mexico.
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Oliva-González
Unidad Periférica de Neurociencia UNAM-INNyN, Instituto de Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", Mexico, D.F., Mexico.
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Torres-Ramos
Laboratorio de Inmunotoxicologia, Facultad de Ciencias Quimicas., Universidad Autonoma de San Luis Potosi, Av. Dr. Manuel Nava No. 6, San Luis Potosi, 78240, SLP, Mexico.
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Aguirre-Bañuelos
Pharmacology and Toxicology Department, College of Pharmacy, University of Arizona, Tucson, AZ, USA.
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Gandolfi
D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D001253:Astrocytes / Q000187:drug effects*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects; D009942:Organometallic Compounds / Q000494:pharmacology*; D017208:Rats, Wistar
D016564:Amyloid beta-Protein Precursor; D016207:Cytokines; D009942:Organometallic Compounds; C406082:monomethylarsonous acid; D053829:Amyloid Precursor Protein Secretases; D016282:Aspartic Acid Endopeptidases; C509281:Bace1 protein, rat
APP; Arsenic; Astrocytes; BACE-1; Cognitive; Inflammation