title: Arylacetamide deacetylase: a novel host factor with important roles in the lipolysis of cellular triacylglycerol stores, VLDL assembly and HCV production.
abstract: OBJECTIVE
  Very low density lipoproteins (VLDLs) are triacylglycerol (TG)-rich lipoproteins produced by the human liver. VLDLs derive the majority of their TG cargo from the lipolysis of TG stored in hepatocellular lipid droplets (LDs). Important roles for LDs and the VLDL secretory pathway in the cell culture production of infectious hepatitis C virus (HCV) have been established. We hypothesized that TG lipolysis and VLDL production are impaired during HCV infection so that these cellular processes can be diverted towards HCV production.
  
  
  METHODS
  We used an HCV permissive cell culture system (JFH-1/HuH7.5 cells) to examine the relationship between TG lipolysis, VLDL assembly, and the HCV lifecycle using standard biochemical approaches.
  
  
  RESULTS
  Lipolysis of cellular TG and VLDL production were impaired in HCV infected cells during the early peak of viral infection. This was partially explained by an apparent deficiency of a putative TG lipase, arylacetamide deacetylase (AADAC). The re-introduction of AADAC to infected cells restored cellular TG lipolysis, indicating a role for HCV-mediated downregulation of AADAC in this process. Defective lipolysis of cellular TG stores and VLDL production were also observed in HuH7.5 cells stably expressing a short hairpin RNA targeting AADAC expression, proving AADAC deficiency contributes to these defective pathways. Finally, impaired production of HCV was observed with AADAC knockdown cells, demonstrating a role for AADAC in the HCV lifecycle.
  
  
  CONCLUSIONS
  This insight into the biology of HCV infection and possibly pathogenesis identifies AADAC as a novel and translationally relevant therapeutic target.
authors.affiliation: Department of Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Mahra
authors.initials: M
authors.lastname: Nourbakhsh
authors.forename: Donna N
authors.initials: DN
authors.lastname: Douglas
authors.forename: Christopher Hao
authors.initials: CH
authors.lastname: Pu
authors.forename: Jamie T
authors.initials: JT
authors.lastname: Lewis
authors.forename: Toshiyasu
authors.initials: T
authors.lastname: Kawahara
authors.forename: Luiz F
authors.initials: LF
authors.lastname: Lisboa
authors.forename: Enhui
authors.initials: E
authors.lastname: Wei
authors.forename: Sonal
authors.initials: S
authors.lastname: Asthana
authors.forename: Ariel D
authors.initials: AD
authors.lastname: Quiroga
authors.forename: Lok Man John
authors.initials: LM
authors.lastname: Law
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: William R
authors.initials: WR
authors.lastname: Addison
authors.forename: Randy
authors.initials: R
authors.lastname: Nelson
authors.forename: Michael
authors.initials: M
authors.lastname: Houghton
authors.forename: Richard
authors.initials: R
authors.lastname: Lehner
authors.forename: Norman M
authors.initials: NM
authors.lastname: Kneteman
mesh_terms: D001055:Apolipoproteins B / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D055785:Gene Knockdown Techniques; D016174:Hepacivirus / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D008066:Lipolysis; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008954:Models, Biological; D014280:Triglycerides / Q000378:metabolism*; D014774:Virulence; D014779:Virus Replication
chemical_list: D001055:Apolipoproteins B; D008079:Lipoproteins, VLDL; D014280:Triglycerides; C569302:AADAC protein, human; D002265:Carboxylic Ester Hydrolases
keywords: AADAC; Activity-based protein profiling; ApoB; Apolipoprotein; Arylacetamide deacetylase; BSA; Carboxylesterase; DMEM; Dulbecco’s Modified Eagle Medium; E600; ELISA; ER; FBS; FP; HCV; Hepatic lipid metabolism; Hepatitis C virus; JFH; Japanese fulminant hepatitis; LD; Lipase; Lipid droplet; MOI; MTP; OA; ORO; Oil Red O; PBS; PDI; RNA; Serine esterase; TG; TGH; Triacylglycerol; Triacylglycerol hydrolase; VLDL; Very low density lipoprotein; apolipoprotein B-100; arylacetamide deacetylase; bovine serum albumin; diethyl-p-nitrophenyl phosphate; endoplasmic reticulum; enzyme-linked immunosorbent assay; fetal bovine serum; fluorophosphonate; hepatitis C virus; lipid droplet; microsomal triglyceride transfer protein; multiplicity of infection; oleic acid; phosphate buffered saline; protein disulfide isomerase; qRT-PCR; quantitative reverse transcriptase-polymerase chain reaction; ribonucleic acid; triacylglycerol; triacylglycerol hydrolase; very low density lipoprotein