title: Proteomic and metabolomic responses to connexin43 silencing in primary hepatocyte cultures.
abstract: Freshly established cultures of primary hepatocytes progressively adopt a foetal-like phenotype and display increased production of connexin43. The latter is a multifaceted cellular entity with variable subcellular locations, including the mitochondrial compartment. Cx43 forms hemichannels and gap junctions that are involved in a plethora of physiological and pathological processes, such as apoptosis. The present study was conducted with the goal of shedding more light onto the role of connexin43 in primary hepatocyte cultures. Connexin43 expression was suppressed by means of RNA interference technology, and the overall outcome of this treatment on the hepatocellular proteome and metabolome was investigated using tandem mass tag-based differential protein profiling and (1)H NMR spectroscopy, respectively. Global protein profiling revealed a number of targets of the connexin43 knock-down procedure, including mitochondrial proteins (heat shock protein 60, glucose-regulated protein 75, thiosulphate sulphurtransferase and adenosine triphosphate synthase) and detoxifying enzymes (glutathione S-transferase μ 2 and cytochrome P450 2C70). At the metabolomic level, connexin43 silencing caused no overt changes, though there was some evidence for a subtle increase in intracellular glycine quantities. Collectively, these data could further substantiate the established existence of a mitochondrial connexin pool and could be reconciled with the previously reported involvement of connexin43 signalling in spontaneously occurring apoptosis in primary hepatocyte cultures.
authors.affiliation: Department of Toxicology, Faculty of Medicine and Pharmacy, Center for Pharmaceutical Research, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussel, Belgium. mvinken@vub.ac.be
authors.forename: Mathieu
authors.initials: M
authors.lastname: Vinken
authors.forename: Michaël
authors.initials: M
authors.lastname: Maes
authors.forename: Rachel
authors.initials: R
authors.lastname: Cavill
authors.forename: Dirk
authors.initials: D
authors.lastname: Valkenborg
authors.forename: James K
authors.initials: JK
authors.lastname: Ellis
authors.forename: Elke
authors.initials: E
authors.lastname: Decrock
authors.forename: Luc
authors.initials: L
authors.lastname: Leybaert
authors.forename: An
authors.initials: A
authors.lastname: Staes
authors.forename: Kris
authors.initials: K
authors.lastname: Gevaert
authors.forename: André G
authors.initials: AG
authors.lastname: Oliveira
authors.forename: Gustavo B
authors.initials: GB
authors.lastname: Menezes
authors.forename: Bruno
authors.initials: B
authors.lastname: Cogliati
authors.forename: Maria Lúcia Zaidan
authors.initials: ML
authors.lastname: Dagli
authors.forename: Timothy M D
authors.initials: TM
authors.lastname: Ebbels
authors.forename: Erwin
authors.initials: E
authors.lastname: Witters
authors.forename: Hector C
authors.initials: HC
authors.lastname: Keun
authors.forename: Tamara
authors.initials: T
authors.lastname: Vanhaecke
authors.forename: Vera
authors.initials: V
authors.lastname: Rogiers
mesh_terms: D000818:Animals; D021461:Animals, Outbred Strains; D015415:Biomarkers / Q000378:metabolism; D002478:Cells, Cultured; D018031:Connexin 43 / Q000235:genetics* / Q000378:metabolism; D020868:Gene Silencing; D022781:Hepatocytes / Q000378:metabolism*; D008297:Male; D055432:Metabolomics; D008930:Mitochondria, Liver / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular; D040901:Proteomics; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers; D018031:Connexin 43; D034741:RNA, Small Interfering