title: The conserved role of the AKT/GSK3 axis in cell survival and glycogen metabolism in Rhipicephalus (Boophilus) microplus embryo tick cell line BME26.
abstract: BACKGROUND
  Tick embryogenesis is a metabolically intensive process developed under tightly controlled conditions and whose components are poorly understood.
  
  
  METHODS
  In order to characterize the role of AKT (protein kinase B) in glycogen metabolism and cell viability, glycogen determination, identification and cloning of an AKT from Rhipicephalus microplus were carried out, in parallel with experiments using RNA interference (RNAi) and chemical inhibition.
  
  
  RESULTS
  A decrease in glycogen content was observed when AKT was chemically inhibited by 10-DEBC treatment, while GSK3 inhibition by alsterpaullone had an opposing effect. RmAKT ORF is 1584-bp long and encodes a polypeptide chain of 60.1 kDa. Phylogenetic and sequence analyses showed significant differences between vertebrate and tick AKTs. Either AKT or GSK3 knocked down cells showed a 70% reduction in target transcript levels, but decrease in AKT also reduced glycogen content, cell viability and altered cell membrane permeability. However, the GSK3 reduction promoted an increase in glycogen content. Additionally, either GSK3 inhibition or gene silencing had a protective effect on BME26 viability after exposure to ultraviolet radiation. R. microplus AKT and GSK3 were widely expressed during embryo development. Taken together, our data support an antagonistic role for AKT and GSK3, and strongly suggest that such a signaling axis is conserved in tick embryos, with AKT located upstream of GSK3.
  
  
  CONCLUSIONS
  The AKT/GSK3 axis is conserved in tick in a way that integrates glycogen metabolism and cell survival, and exhibits phylogenic differences that could be important for the development of novel control methods.
authors.affiliation: LQFPP, CBB and Unidade de Experimentação Animal, RJ, UENF, Avenida Alberto Lamego, 2000, Horto, CEP 28013-602, Campos dos Goytacazes, RJ, Brazil.
authors.forename: Leonardo Araujo
authors.initials: LA
authors.lastname: de Abreu
authors.forename: Christiano
authors.initials: C
authors.lastname: Calixto
authors.forename: Camila Fernanda
authors.initials: CF
authors.lastname: Waltero
authors.forename: Bárbara Pitta
authors.initials: BP
authors.lastname: Della Noce
authors.forename: Naftaly Wang'ombe
authors.initials: NW
authors.lastname: Githaka
authors.forename: Adriana
authors.initials: A
authors.lastname: Seixas
authors.forename: Luís Fernando
authors.initials: LF
authors.lastname: Parizi
authors.forename: Satoru
authors.initials: S
authors.lastname: Konnai
authors.forename: Itabajara da Silva Júnior
authors.initials: Ida S
authors.lastname: Vaz
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ohashi
authors.forename: Carlos
authors.initials: C
authors.lastname: Logullo
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D001552:Benzazepines / Q000494:pharmacology; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian; D005786:Gene Expression Regulation / Q000528:radiation effects; D006003:Glycogen / Q000235:genetics / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D050261:Glycogenolysis / Q000235:genetics* / Q000528:radiation effects; D007211:Indoles / Q000494:pharmacology; D016366:Open Reading Frames; D010078:Oxazines / Q000494:pharmacology; D010802:Phylogeny; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D048494:Rhipicephalus / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000528:radiation effects; D013045:Species Specificity; D014466:Ultraviolet Rays
chemical_list: C553100:10-(4'-(N-diethylamino)butyl)-2-chlorophenoxazine; D060829:Arthropod Proteins; D001552:Benzazepines; D007211:Indoles; D010078:Oxazines; D034741:RNA, Small Interfering; C120793:alsterpaullone; D006003:Glycogen; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3