Histone Deacetylases Enhance Ca
2+-Activated K⁺ Channel K
Ca3.1 Expression in Murine Inflammatory CD4⁺ T Cells.
Int J Mol Sci 2018;
19:ijms19102942. [PMID:
30262728 PMCID:
PMC6213394 DOI:
10.3390/ijms19102942]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/19/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022] Open
Abstract
The up-regulated expression of the Ca2+-activated K+ channel KCa3.1 in inflammatory CD4+ T cells has been implicated in the pathogenesis of inflammatory bowel disease (IBD) through the enhanced production of inflammatory cytokines, such as interferon-γ (IFN-γ). However, the underlying mechanisms have not yet been elucidated. The objective of the present study is to clarify the involvement of histone deacetylases (HDACs) in the up-regulation of KCa3.1 in the CD4+ T cells of IBD model mice. The expression levels of KCa3.1 and its regulators, such as function-modifying molecules and transcription factors, were quantitated using a real-time polymerase chain reaction (PCR) assay, Western blotting, and depolarization responses, which were induced by the selective KCa3.1 blocker TRAM-34 (1 μM) and were measured using a voltage-sensitive fluorescent dye imaging system. The treatment with 1 μM vorinostat, a pan-HDAC inhibitor, for 24 h repressed the transcriptional expression of KCa3.1 in the splenic CD4+ T cells of IBD model mice. Accordingly, TRAM-34-induced depolarization responses were significantly reduced. HDAC2 and HDAC3 were significantly up-regulated in the CD4+ T cells of IBD model mice. The down-regulated expression of KCa3.1 was observed following treatments with the selective inhibitors of HDAC2 and HDAC3. The KCa3.1 K+ channel regulates inflammatory cytokine production in CD4+ T cells, mediating epigenetic modifications by HDAC2 and HDAC3.
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