In this study, cyanine cations with various counter anions were prepared as examples of ionic materials constructed using charged π-conjugated systems. A series of ion pairs was obtained by anion exchange reactions using iodide salts of carbocyanine dyes. The optical properties were measured by UV/vis absorption and fluorescence spectroscopy; measurements performed in CHCl 3 (less-polar solvent) were altered by the influence of the counter anions. The packing structures of nine crystals were determined by single-crystal X-ray analysis. Moreover, the locations of the anions relative to the cations were stabilized by hydrogen bonding and categorized into two types. In addition, delocalization of the negative charge of the anions on cyanine cations was explained by density functional theory calculations. Furthermore, it was concluded that the stack formation of cyanine cations depends on the size and structure of the anions.
Background: Inflammatory responses could be involved in induction of Alzheimer's disease (AD). Microglia are known to act as the main immunologic effector cell in the central nervous system, and contribute to the pathological states of AD. Activation of α7 nicotinic acetylcholine receptor (α7-nAChR) potentiated microglial phagocytosis of amyloid-β. By contrast, α7-nAChR was decreased along with the progression of AD in rodent models. The current study has investigated the mechanisms underlying downregulation of microglial α7-nAChR expression by activation of toll-like receptor 4 (TLR4). Method: Mice microglial cell-line BV2 cells were used for investigation of downregulation of α7-nAChR expression. The mRNA expression levels of α7-nAChR was measured by the real-time PCR. Results: Treatment of BV2 cells with lipopolysaccharide (LPS) significantly decreased the expression of α7-nAChR in dose-and time dependent manner. The LPS-induced downregulation of α7-nAChR mRNA was mediated by TLR4 and histone deacetylase (HDAC), but not DNA methyltransferase. Conclusion: The current study demonstrated that the TLR4-HDAC pathway might contribute to the downregulation of α7-nAChR in microglia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.