title: Paradoxical role of 3-methyladenine in pyocyanin-induced toxicity in 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells.
abstract: The role of autophagy in pyocyanin (PCN)-induced toxicity in the central nervous system (CNS) remains unclear, with only evidence from our group identifying it as a mechanism underlying toxicity in 1321N1 astrocytoma cells. Therefore, the aim of this study was to further examine the role of autophagy in PCN-induced toxicity in the CNS. To achieve this, we exposed 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells to PCN (0-100 μmol/L) and tested the contribution of autophagy by measuring the impact of the autophagy inhibitor 3-methyladenine (3-MA) using a series of biochemical and molecular markers. Pretreatment of 1321N1 astrocytoma cells with 3-MA (5 mmol/L) decreased the PCN-induced acidic vesicular organelle and autophagosome formation as measured using acridine orange and green fluorescent protein-LC3 -LC3 fluorescence, respectively. Furthermore, 3-MA (5 mmol/L) significantly protected 1321N1 astrocytoma cells against PCN-induced toxicity. In contrast pretreatment with 3-MA (5 mmol/L) increased PCN-induced toxicity in SH-SY5Y neuroblastoma cells. Given the influence of autophagy in inflammatory responses, we investigated whether the observed effects in this study involved inflammatory mediators. The PCN (100 μmol/L) significantly increased the production of interleukin-8 (IL-8), prostaglandin E2 (PGE₂), and leukotriene B4 (LTB₄) in both cell lines. Consistent with its paradoxical role in modulating PCN-induced toxicity, 3-MA (5 mmol/L) significantly reduced the PCN-induced production of IL-8, PGE₂, and LTB₄ in 1321N1 astrocytoma cells but augmented their production in SH-SY5Y neuroblastoma cells. In conclusion, we show here for the first time the paradoxical role of autophagy in mediating PCN-induced toxicity in 1321N1 astrocytoma and SH-SY5Y neuroblastoma cells and provide novel evidence that these actions may be mediated by effects on IL-8, PGE₂, and LTB₄ production.
authors.affiliation: School of Pharmacy, Gold Coast Campus, Griffith University, Queensland 4222, Australia.
authors.forename: Amelia J
authors.initials: AJ
authors.lastname: McFarland
authors.forename: Gary D
authors.initials: GD
authors.lastname: Grant
authors.forename: Anthony V
authors.initials: AV
authors.lastname: Perkins
authors.forename: Cameron
authors.initials: C
authors.lastname: Flegg
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Davey
authors.forename: Tristan J
authors.initials: TJ
authors.lastname: Allsopp
authors.forename: Gillian
authors.initials: G
authors.lastname: Renshaw
authors.forename: Justin
authors.initials: J
authors.lastname: Kavanagh
authors.forename: Catherine M
authors.initials: CM
authors.lastname: McDermott
authors.forename: Shailendra
authors.initials: S
authors.lastname: Anoopkumar-Dukie
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D001254:Astrocytoma / Q000378:metabolism*; D001343:Autophagy / Q000502:physiology; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D015232:Dinoprostone / Q000235:genetics / Q000378:metabolism; D004359:Drug Therapy, Combination; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D007975:Leukotriene B4 / Q000235:genetics / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism*; D011710:Pyocyanine / Q000633:toxicity*; D013194:Staining and Labeling
chemical_list: D016209:Interleukin-8; D007975:Leukotriene B4; C025946:3-methyladenine; D011710:Pyocyanine; D053148:Caspase 3; D000225:Adenine; D015232:Dinoprostone
keywords: 3-methyladenine; autophagy; inflammation; pyocyanin