title: Adenoviral CCN gene transfers induce in vitro and in vivo endoplasmic reticulum stress and unfolded protein response.
abstract: The endoplasmic reticulum (ER) is primarily recognized as the site of synthesis and folding of secreted membrane-bound and certain organelle-targeted proteins. Optimum protein folding requires several factors, including ATP, Ca2+and an oxidizing environment to allow disulphide-bond formation. ER is highly sensitive to stress that perturb cellular energy levels, the redox state or the Ca2+concentration. Such stresses reduce the protein folding capacity of the ER, resulting in the accumulation and aggregation of unfolded proteins, a condition referred to as unfolded protein response (UPR). Matricellular proteins of the CCN (CYR61, CTGF, NOV) family play essential roles in extracellular matrix signaling and turnover. They exhibit a similar type of organization and share a closely related primary structure, including 38 conserved cysteine residues. Since CCN1/CYR61 overexpression in hepatic stellate cells (HSC) induces ER stress-related apoptosis, we endeavored to investigate whether the adenovirus mediated gene transfer of other members of CCN proteins incurs ER stress in primary HSC and hepatocytes. We found Ad5-CMV-CCN2, Ad5-CMV-CCN3 and Ad5-CMV-CCN4 to induce ER stress and UPR comparable to Ad5-CMV-CCN1. UPR is a pro-survival response to reduce accumulation of unfolded proteins and restore normal ER functioning. If, however protein aggregation is persistent and the stress cannot be resolved, signaling switches from pro-survival to pro-apoptosis. The observed CCN-induced UPR is relevant in wound healing responses and essential for hepatic tissue repair following liver injury. Adenoviral gene transfer induced massive amounts of matricellular proteins proving to effectively mitigate liver fibrosis if targeted cell specific in HSC and myofibroblasts.
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany. Electronic address: ekamphorst@ukaachen.de.
authors.forename: Erawan
authors.initials: E
authors.lastname: Borkham-Kamphorst
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Bettina Therese
authors.initials: BT
authors.lastname: Steffen
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Eddy
authors.initials: E
authors.lastname: Van de Leur
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Lidia
authors.initials: L
authors.lastname: Tihaa
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Haas
authors.affiliation: Department of Medicine III, RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Marius M
authors.initials: MM
authors.lastname: Woitok
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany.
authors.forename: Steffen K
authors.initials: SK
authors.lastname: Meurer
authors.affiliation: Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH Aachen University Hospital, Aachen, Germany. Electronic address: rweiskirchen@ukaachen.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Weiskirchen
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis; D055511:CCN Intercellular Signaling Proteins / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D016922:Cellular Senescence; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000473:pathology; D059865:Endoplasmic Reticulum Stress; D005822:Genetic Vectors; D055166:Hepatic Stellate Cells / Q000378:metabolism / Q000473:pathology; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008106:Liver Cirrhosis, Experimental / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008810:Mice, Inbred C57BL; D058628:Myofibroblasts / Q000378:metabolism / Q000473:pathology; D066329:Protein Aggregates; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D014161:Transduction, Genetic; D014162:Transfection / Q000379:methods*; D056811:Unfolded Protein Response
chemical_list: D055511:CCN Intercellular Signaling Proteins; D066329:Protein Aggregates
keywords: CCN proteins; ER stress; hepatic stellate cells; hepatocytes; matricellular proteins; unfolded protein response