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BioMed Research International
Volume 2014, Article ID 698609, 14 pages
http://dx.doi.org/10.1155/2014/698609
Research Article

Human Endogenous Retrovirus W Activity in Cartilage of Osteoarthritis Patients

1Department of Laboratory Medicine, University Hospital of North Norway, Sykehusveien 38, 9038 Tromsø, Norway
2Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø, MH-Building, 9037 Tromsø, Norway
3Genøk Centre of Biosafety, Science Park, Sykehusveien 23, 9294 Tromsø, Norway
4Department of Orthopaedics, University Hospital of North Norway, Sykehusveien 38, 3098 Tromsø, Norway
5Department of Electron Microscopy, Institute of Medical Biology, Faculty of Health Sciences, University of Tromsø, Sykehusveien 44, 9037 Tromsø, Norway
6Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, MH-Building, 9037 Tromsø, Norway

Received 7 March 2014; Accepted 25 June 2014; Published 22 July 2014

Academic Editor: Anca Irinel Catrina

Copyright © 2014 Signy Bendiksen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The etiology of viruses in osteoarthritis remains controversial because the prevalence of viral nucleic acid sequences in peripheral blood or synovial fluid from osteoarthritis patients and that in healthy control subjects are similar. Until now the presence of virus has not been analyzed in cartilage. We screened cartilage and chondrocytes from advanced and non-/early osteoarthritis patients for parvovirus B19, herpes simplex virus-1, Epstein Barr virus, cytomegalovirus, human herpes virus-6, hepatitis C virus, and human endogenous retroviruses transcripts. Endogenous retroviruses transcripts, but none of the other viruses, were detected in 15 out the 17 patients. Sequencing identified the virus as HERV-WE1 and E2. HERV-W activity was confirmed by high expression levels of syncytin, dsRNA, virus budding, and the presence of virus-like particles in all advanced osteoarthritis cartilages examined. Low levels of HERV-WE1, but not E2 envelope RNA, were observed in 3 out of 8 non-/early osteoarthritis patients, while only 3 out of 7 chondrocytes cultures displayed low levels of syncytin, and just one was positive for virus-like particles. This study demonstrates for the first time activation of HERV-W in cartilage of osteoarthritis patients; however, a causative role for HERV-W in development or deterioration of the disease remains to be proven.