Rubio N, Almanza A, Mercado F, Arévalo MÁ, Garcia-Segura LM, Vega R, Soto E. Upregulation of voltage-gated Ca2+ channels in mouse astrocytes infected with Theiler's murine encephalomyelitis virus (TMEV).
Neuroscience 2013;
247:309-18. [PMID:
23742846 DOI:
10.1016/j.neuroscience.2013.05.049]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Revised: 05/15/2013] [Accepted: 05/20/2013] [Indexed: 11/25/2022]
Abstract
Theiler's murine encephalomyelitis virus (TMEV) induces demyelination in susceptible strains of mice through a CD4(+) Th1 T cell-mediated immunopathological process. TMEV infection produces a syndrome in mice that resembles multiple sclerosis. In this work, we focused on the increased expression of the genes encoding voltage-gated Ca(2+) channel subunits in SJL/J mouse astrocytes infected in culture with a BeAn strain of TMEV. Affymetrix DNA murine genome U74v2 DNA microarray hybridized with cRNA from mock- and TMEV-infected astrocytes revealed the upregulation of four sequences encoding Ca(2+)-binding and Ca(2+) channel subunit proteins. The DNA hybridization results were further validated using conventional RT-PCR and quantitative RT-PCR, demonstrating the increased expression of mRNA encoding channel subunit proteins. Western blotting also showed the increased synthesis of L- and N-type channel subunit specific proteins after infection. The reduced expression and the functional upregulation of functional voltage-gated Ca(2+) channels in mock- and TMEV-infected cells, respectively, was demonstrated using voltage clamp experiments. TMEV infection in mouse astrocytes induced a Ca(2+) current with a density proportional to the amount of viral particles used for infection. The use of Ca(2+) channel blockers, nimodipine and ω-conotoxin-GVIA, showed that both functional L- and N-type Ca(2+) channels were upregulated in infected astrocytes. The upregulation of Ca(2+) channels in astrocytes after TMEV infection provides insight into the molecular processes and potential role of astrocyte Ca(2+) dysregulation in the pathophysiology of encephalomyelitis and is important for the development of novel therapeutic strategies leading to prevention of neurodegeneration.
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