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Piña-Oviedo S, Khalili K, Del Valle L. Hypoxia inducible factor-1 alpha activation of the JCV promoter: role in the pathogenesis of progressive multifocal leukoencephalopathy. Acta Neuropathol 2009; 118:235-47. [PMID: 19360424 DOI: 10.1007/s00401-009-0533-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 03/12/2009] [Accepted: 03/30/2009] [Indexed: 11/25/2022]
Abstract
Activation of viral promoter transcription is a crucial event in the life cycle of several viruses. Hypoxia inducible factor-1 alpha (HIF-1alpha) is an inducible transcription factor whose activity is dependent on environmental conditions, most notably oxygen levels and cellular stress. HIF-1alpha has been implicated in the pathogenesis of several viruses, including HIV-1, HHV-8 and RSV. Under hypoxic conditions or oxidative stress, HIF-1alpha becomes stable and translocates to the nucleus, where it modulates gene transcription. The objective of the present study was to investigate a possible role for HIF-1alpha in the activation of JCV. Glial cell cultures infected with JCV demonstrated a significant increase in the levels of HIF-1alpha, in where it is located to the nucleus. Immunohistochemical studies corroborated upregulation of HIF-1alpha in JCV infected oligodendrocytes and astrocytes in clinical samples of PML compared with normal glial cells from the same samples in which HIF-1alpha expression is weak. CAT assays performed in co-transfected glial cells demonstrated activation of the JCV early promoter in the presence of HIF-1alpha. This activation was potentiated in the presence of Smad3 and Smad4. Finally, chromatin immunoprecipitation assays demonstrated the binding of HIF-1alpha to the JCV control region. These results suggest a role for HIF-1alpha in the activation of JCV; understanding of this pathway may lead to the development of more effective therapies for PML, thus far an incurable disease.
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Affiliation(s)
- Sergio Piña-Oviedo
- Department of Neuroscience, Center for Neurovirology and Neuropathology Core, Temple University School of Medicine, 1900 N. 12th Street, Philadelphia, PA 19122, USA
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Servais C, Caillet-Fauquet P, Draps ML, Velu T, de Launoit Y, Brandenburger A. Hypoxic-response elements in the oncolytic parvovirus Minute virus of mice do not allow for increased vector production at low oxygen concentration. J Gen Virol 2006; 87:1197-1201. [PMID: 16603521 DOI: 10.1099/vir.0.81754-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Vectors derived from the autonomous parvovirus Minute virus of mice, MVM(p), are promising tools for the gene therapy of cancer. The validation of their in vivo anti-tumour effect is, however, hampered by the difficulty to produce high-titre stocks. In an attempt to increase vector titres, host cells were subjected to low oxygen tension (hypoxia). It has been shown that a number of viruses are produced at higher titres under these conditions. This is the case, among others, for another member of the family Parvoviridae, the erythrovirus B19 virus. Hypoxia stabilizes a hypoxia-inducible transcription factor (HIF-1alpha) that interacts with a 'hypoxia-responsive element' (HRE), the consensus sequence of which ((A)/(G)CGTG) is present in the B19 and MVM promoters. Whilst the native P4 promoter was induced weakly in hypoxia, vector production was reduced dramatically, and adding HRE elements to the P4 promoter of the vector did not alleviate this reduction. Hypoxia has many effects on cell metabolism. Therefore, even if the P4 promoter is activated, the cellular factors that are required for the completion of the parvoviral life cycle may not be expressed.
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Affiliation(s)
- Charlotte Servais
- Laboratoire de Cytologie et de Cancérologie Expérimentale, IBMM-IRIBHM, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Perrine Caillet-Fauquet
- Laboratoire de Virologie Moléculaire, Faculté de Médecine, Campus Erasme, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium
| | - Marie-Louise Draps
- Laboratoire de Virologie Moléculaire, Faculté de Médecine, Campus Erasme, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium
| | - Thierry Velu
- Laboratoire de Cytologie et de Cancérologie Expérimentale, IBMM-IRIBHM, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Yvan de Launoit
- UMR 8117 CNRS, Université de Lille 1, Institut Pasteur Lille, Institut de Biologie de Lille, Lille, France
- Laboratoire de Virologie Moléculaire, Faculté de Médecine, Campus Erasme, Université Libre de Bruxelles, Route de Lennik 808, B-1070 Bruxelles, Belgium
| | - Annick Brandenburger
- Laboratoire de Cytologie et de Cancérologie Expérimentale, IBMM-IRIBHM, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
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