PMID- 24586264 OWN - NLM STAT- MEDLINE DCOM- 20141104 LR - 20211021 IS - 1932-6203 (Electronic) IS - 1932-6203 (Linking) VI - 9 IP - 2 DP - 2014 TI - Tempol, an intracellular antioxidant, inhibits tissue factor expression, attenuates dendritic cell function, and is partially protective in a murine model of cerebral malaria. PG - e87140 LID - 10.1371/journal.pone.0087140 [doi] LID - e87140 AB - BACKGROUND: The role of intracellular radical oxygen species (ROS) in pathogenesis of cerebral malaria (CM) remains incompletely understood. METHODS AND FINDINGS: We undertook testing Tempol--a superoxide dismutase (SOD) mimetic and pleiotropic intracellular antioxidant--in cells relevant to malaria pathogenesis in the context of coagulation and inflammation. Tempol was also tested in a murine model of CM induced by Plasmodium berghei Anka infection. Tempol was found to prevent transcription and functional expression of procoagulant tissue factor in endothelial cells (ECs) stimulated by lipopolysaccharide (LPS). This effect was accompanied by inhibition of IL-6, IL-8, and monocyte chemoattractant protein (MCP-1) production. Tempol also attenuated platelet aggregation and human promyelocytic leukemia HL60 cells oxidative burst. In dendritic cells, Tempol inhibited LPS-induced production of TNF-alpha, IL-6, and IL-12p70, downregulated expression of co-stimulatory molecules, and prevented antigen-dependent lymphocyte proliferation. Notably, Tempol (20 mg/kg) partially increased the survival of mice with CM. Mechanistically, treated mice had lowered plasma levels of MCP-1, suggesting that Tempol downmodulates EC function and vascular inflammation. Tempol also diminished blood brain barrier permeability associated with CM when started at day 4 post infection but not at day 1, suggesting that ROS production is tightly regulated. Other antioxidants-such as alpha-phenyl N-tertiary-butyl nitrone (PBN; a spin trap), MnTe-2-PyP and MnTBAP (Mn-phorphyrin), Mitoquinone (MitoQ) and Mitotempo (mitochondrial antioxidants), M30 (an iron chelator), and epigallocatechin gallate (EGCG; polyphenol from green tea) did not improve survival. By contrast, these compounds (except PBN) inhibited Plasmodium falciparum growth in culture with different IC50s. Knockout mice for SOD1 or phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (gp91(phox-/-)) or mice treated with inhibitors of SOD (diethyldithiocarbamate) or NADPH oxidase (diphenyleneiodonium) did not show protection or exacerbation for CM. CONCLUSION: Results with Tempol suggest that intracellular ROS contribute, in part, to CM pathogenesis. Therapeutic targeting of intracellular ROS in CM is discussed. FAU - Francischetti, Ivo M B AU - Francischetti IM AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Gordon, Emile AU - Gordon E AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Bizzarro, Bruna AU - Bizzarro B AD - Laboratory of Experimental Immunology, Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil. FAU - Gera, Nidhi AU - Gera N AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Andrade, Bruno B AU - Andrade BB AD - Laboratory of Parasitic Diseases, NIAID/NIH, Bethesda, Maryland, United States of America. FAU - Oliveira, Fabiano AU - Oliveira F AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Ma, Dongying AU - Ma D AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Assumpcao, Teresa C F AU - Assumpcao TC AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Ribeiro, Jose M C AU - Ribeiro JM AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Pena, Mirna AU - Pena M AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Qi, Chen-Feng AU - Qi CF AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Diouf, Ababacar AU - Diouf A AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Moretz, Samuel E AU - Moretz SE AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Long, Carole A AU - Long CA AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Ackerman, Hans C AU - Ackerman HC AD - Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Pierce, Susan K AU - Pierce SK AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America. FAU - Sa-Nunes, Anderson AU - Sa-Nunes A AD - Laboratory of Experimental Immunology, Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil. FAU - Waisberg, Michael AU - Waisberg M AD - Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America ; University of Virginia, Department of Pathology, Charlottesville, Virginia, United States of America. LA - eng PT - Journal Article DEP - 20140228 PL - United States TA - PLoS One JT - PloS one JID - 101285081 RN - 0 (Antioxidants) RN - 0 (Chemokine CCL2) RN - 0 (Cyclic N-Oxides) RN - 0 (Interleukin-6) RN - 0 (Interleukin-8) RN - 0 (Reactive Oxygen Species) RN - 0 (Spin Labels) RN - 9035-58-9 (Thromboplastin) RN - U78ZX2F65X (tempol) SB - IM MH - Animals MH - Antioxidants/*pharmacology/therapeutic use MH - Cells, Cultured MH - Chemokine CCL2/metabolism MH - Cyclic N-Oxides/*pharmacology/therapeutic use MH - Dendritic Cells/*drug effects/*metabolism MH - Enzyme-Linked Immunosorbent Assay MH - Humans MH - Interleukin-6/metabolism MH - Interleukin-8/metabolism MH - Malaria, Cerebral/*drug therapy/metabolism MH - Mice MH - Reactive Oxygen Species/metabolism MH - Real-Time Polymerase Chain Reaction MH - Spin Labels MH - Thromboplastin/*metabolism PMC - PMC3938406 COIS- Competing Interests: The authors have declared that no competing interests exist. EDAT- 2014/03/04 06:00 MHDA- 2014/11/05 06:00 PMCR- 2014/02/28 CRDT- 2014/03/04 06:00 PHST- 2013/08/16 00:00 [received] PHST- 2013/12/18 00:00 [accepted] PHST- 2014/03/04 06:00 [entrez] PHST- 2014/03/04 06:00 [pubmed] PHST- 2014/11/05 06:00 [medline] PHST- 2014/02/28 00:00 [pmc-release] AID - PONE-D-13-33787 [pii] AID - 10.1371/journal.pone.0087140 [doi] PST - epublish SO - PLoS One. 2014 Feb 28;9(2):e87140. doi: 10.1371/journal.pone.0087140. eCollection 2014.