title: Antioxidants and NOS inhibitors selectively targets manganese-induced cell volume via Na-K-Cl cotransporter-1 in astrocytes.
abstract: Manganese has shown to be involved in astrocyte swelling. Several factors such as transporters, exchangers and ion channels are attributed to astrocyte swelling as a result in the deregulation of cell volume. Products of oxidation and nitration have been implied to be involved in the pathophysiology of swelling; however, the direct link and mechanism of manganese induced astrocyte swelling has not been fully elucidated. In the current study, we used rat primary astrocyte cultures to investigate the activation of Na-K-Cl cotransporter-1 (NKCC1) a downstream mechanism for free radical induced astrocyte swelling as a result of manganese toxicity. Our results showed manganese, oxidants and NO donors as potent inducer of oxidation and nitration of NKCC1. Our results further confirmed that manganese (50 μM) increased the total protein, phosphorylation and activity of NKCC1 as well as cell volume (p < 0.05 vs. control). NKCC1 inhibitor (bumetanide), NKCC1-siRNA, antioxidants; DMTU, MnTBAP, tempol, catalase and Vit-E, NOS inhibitor; L-NAME, peroxinitrite scavenger; uric acid all significantly reversed the effects of NKCC1 activation (p < 0.05). From the current investigation we infer that manganese or oxidants and NO induced activation, oxidation/nitration of NKCC1 play an important role in the astrocyte swelling.
authors.affiliation: Department of Medical Rehabilitation Sciences, College of Applied Medical Sciences, King Khalid University, PO Box 3236, Abha, Saudi Arabia.
authors.forename: Khalid A
authors.initials: KA
authors.lastname: Alahmari
authors.affiliation: Volunteer Summer Research Intern at Department of Pharmacy, Elizabeth City State University, Elizabeth City, NC 27909, USA.
authors.forename: Harini
authors.initials: H
authors.lastname: Prabhakaran
authors.affiliation: Department of Pharmacy and Health Professions, Elizabeth City State University, Elizabeth City, NC 27909, USA.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Prabhakaran
authors.affiliation: Center for Stem Cell Research, Department of Clinical Biochemistry, College of Medicine, King Khalid University, PO Box 3236, Abha, Saudi Arabia.
authors.forename: Harish C
authors.initials: HC
authors.lastname: Chandramoorthy
authors.affiliation: Department of Medical Rehabilitation Sciences, College of Applied Medical Sciences, King Khalid University, PO Box 3236, Abha, Saudi Arabia. Electronic address: ramagounder@kku.edu.sa.
authors.forename: Ramakrishnan
authors.initials: R
authors.lastname: Ramugounder
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000975:Antioxidants / Q000494:pharmacology*; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002034:Bumetanide / Q000494:pharmacology; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008345:Manganese / Q000633:toxicity*; D020030:Nitric Oxide Donors / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology; D010084:Oxidation-Reduction / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D034741:RNA, Small Interfering; D051381:Rats; D026361:Reactive Nitrogen Species / Q000378:metabolism; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000494:pharmacology; D064506:Solute Carrier Family 12, Member 2 / Q000235:genetics / Q000378:metabolism*; D014527:Uric Acid / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D016877:Oxidants; D034741:RNA, Small Interfering; D026361:Reactive Nitrogen Species; C578879:Slc12a2 protein, rat; D049994:Sodium Potassium Chloride Symporter Inhibitors; D064506:Solute Carrier Family 12, Member 2; D002034:Bumetanide; D014527:Uric Acid; D008345:Manganese; D019001:Nitric Oxide Synthase
keywords: Astrocyte; Cell volume; Manganese; NKCC1; NO donors; Oxidants