title: Effect of microcystin on leukocyte viability and function.
abstract: Microcystin (MC) has been found in several areas of the world. In addition to its hepatotoxicity, microcystin may have an immunomodulatory effect. Considering that patients receiving hemodialysis may be chronically exposed to variable concentrations of MC, and that they present important changes in this immune response, we have assessed the effect of MC on the function of leukocytes. Polymorphonuclear leukocytes isolated from healthy volunteers (HV) and patients receiving hemodialysis (HD) were incubated with microcystin (10 microg/L) for 24h and evaluated for reactive oxygen species production (ROS), phagocytosis and apoptosis. Monocytes incubated with and without LPS (100 ng/mL) and microcystin for 24h were assessed for TNFalpha and IL-10 production. Leukocytes of HV presented an increase in apoptosis rates and leukocytes from HD exhibited a lower production of oxygen-reactive species, both spontaneously and after stimulus with S. aureus, when compared with leukocytes incubated without toxin. Monocytes presented an increase in cytokine production after stimulation by LPS in both groups, but there was no difference between the groups with and without MC that were incubated with or without LPS. Low concentrations of microcystin can induce mild changes in leukocyte function of HV and HDP, particularly in the ability to produce ROS.
authors.affiliation: Nephrology Division, Department of Medicine, Federal University of São Paulo-UNIFESP, São Paulo, SP, Brazil. elsapetry@yahoo.com.br
authors.forename: Elsa Alidia Petry
authors.initials: EA
authors.lastname: Gonçalves
authors.forename: Maria Aparecida
authors.initials: MA
authors.lastname: Dalboni
authors.forename: Aline Trevisan
authors.initials: AT
authors.lastname: Peres
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Manfredi
authors.forename: Silvia Regina
authors.initials: SR
authors.lastname: Manfredi
authors.forename: Sandra Maria
authors.initials: SM
authors.lastname: Azevedo
authors.forename: Valéria F
authors.initials: VF
authors.lastname: Magalhães
authors.forename: Sergio
authors.initials: S
authors.lastname: Draibe
authors.forename: Maria Eugenia F
authors.initials: ME
authors.lastname: Canziani
authors.forename: Miguel
authors.initials: M
authors.lastname: Cendoroglo
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000628:therapy; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D052998:Microcystins; D010456:Peptides, Cyclic / Q000494:pharmacology*; D010587:Phagocytosis / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D006435:Renal Dialysis; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D052998:Microcystins; D010456:Peptides, Cyclic; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; C078588:microcystin