title: Apoptotic activity and gene responses in Drosophila melanogaster S2 cells, induced by azadirachtin A.
abstract: BACKGROUND
  Azadirachtin has been used as an antifeedant and growth disruption agent for many insect species. Previous investigations have reported the apoptotic effects of azadirachtin on some insect cells, but the molecular mechanisms are still not clear. This study investigated the underlying molecular mechanisms for the apoptotic effects induced by azadirachtin on Drosophila melanogaster S2 cells in vitro.
  
  
  RESULTS
  The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay demonstrated that azadirachtin exhibited significant cytotoxicity to S2 cells in a time- and dose-dependent manner. The changes in cellular morphology and the DNA fragmentation demonstrated that azadirachtin induced remarkable apoptosis of S2 cells. Expression levels of 276 genes were found to be significantly changed in S2 cells after exposure to azadirachtin, as detected by Drosophila genome array. Among these genes, calmodulin (CaM) was the most highly upregulated gene. Azadirachtin was further demonstrated to trigger intracellular Ca(2+) release in S2 cells. The genes related to the apoptosis pathway, determined from chip data, were validated by the real-time quantitative polymerase chain reaction method.
  
  
  CONCLUSIONS
  The results showed that azadirachtin-mediated intracellular Ca(2+) release was the primary event that triggered apoptosis in Drosophila S2 cells through both pathways of the Ca(2+) -CaM and EcR/Usp signalling cascade. © 2015 Society of Chemical Industry.
authors.affiliation: Key Laboratory of Green Pesticide and Agriculture Bioengineering of Ministry of Education, Guizhou University, Guiyang, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: Institute of Agro-Bioengineering, Guizhou University, Guiyang, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Li
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Guiyang, China.
authors.forename: Xueqin
authors.initials: X
authors.lastname: Ran
authors.affiliation: Institute of Agro-Bioengineering, Guizhou University, Guiyang, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Faculty of Animal Science and Veterinary Medicine, Guiyang, China.
authors.forename: Rutao
authors.initials: R
authors.lastname: Lin
authors.affiliation: Key Laboratory of Green Pesticide and Agriculture Bioengineering of Ministry of Education, Guizhou University, Guiyang, China.|Institute of Agro-Bioengineering, Guizhou University, Guiyang, China.|Tongren College, Tongren, China.
authors.forename: Jiafu
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D004331:Drosophila melanogaster / Q000187:drug effects*; D036701:Limonins / Q000633:toxicity*; D040081:Protein Array Analysis; D059467:Transcriptome
chemical_list: D036701:Limonins; C010329:azadirachtin
keywords: Drosophila S2 cells; apoptosis; azadirachtin; calcium; gene expression