Stimulation of toll-like receptor 4 downregulates the expression of α7 nicotinic acetylcholine receptors via histone deacetylase in rodent microglia
| Autor: | Masatoshi Takemura, Norimitsu Morioka, Momoka Iwamoto, Sayuri Kimura, Yoshihiro Nakata, Kazue Hisaoka-Nakashima, Yoki Nakamura, Naoki Takada |
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| Rok vydání: | 2020 |
| Předmět: |
Lipopolysaccharides
0301 basic medicine alpha7 Nicotinic Acetylcholine Receptor Down-Regulation Gene Expression Histone Deacetylases Cell Line Mice 03 medical and health sciences Cellular and Molecular Neuroscience Histone H3 0302 clinical medicine Downregulation and upregulation medicine Animals Neuroinflammation Dose-Response Relationship Drug Microglia Chemistry Histone deacetylase 2 Cell Biology Cell biology Toll-Like Receptor 4 Nicotinic acetylcholine receptor 030104 developmental biology medicine.anatomical_structure Trichostatin A nervous system Histone deacetylase 030217 neurology & neurosurgery medicine.drug |
| Zdroj: | Neurochemistry International. 138:104751 |
| ISSN: | 0197-0186 |
| DOI: | 10.1016/j.neuint.2020.104751 |
| Popis: | Microglia have both protective and degenerative roles in the central nervous system. The α7 nicotinic acetylcholine receptor (nAChR) is crucial in the regulation of the neuroprotective role in microglia. Recent studies have demonstrated decreased expression of α7 nAChR in brain in response to neuroinflammation, but the mechanism mediating the downregulation of the α7 nAChR has yet to be elaborated. Treatment of microglial cell line BV2 cells or rat primary cultured microglia with the inflammogen lipopolysaccharide (LPS) significantly decreased the expression of α7 nAChR mRNA in a time and concentration-dependent manner. The effects of LPS were prevented by pretreatment with TAK-242, a toll-like receptor 4 (TLR4) blocker. The LPS-induced downregulation of α7 nAChR was also prevented with trichostatin A, a histone deacetylase (HDAC) inhibitor, but not 5-aza-2'-deoxycytidine, a DNA methyltransferase inhibitor. Further pharmacological probing revealed that HDAC2 and HDAC3 were involved in the effects of LPS. Treatment of BV2 cells with LPS significantly reduced acetylation of histone H3 at lysine 9 of the α7 nAChR promoter. The current findings demonstrate that inflammation-evoked activation of TLR4 leads to the reduction of the neuroprotective function of microglia through the downregulation of the α7 nAChR. Also, histone modification could be crucial in the regulation of the neuroprotective role of microglia during neuroinflammatory states. |
| Databáze: | OpenAIRE |
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