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A Macrophage Reporter Cell Assay to Examine Toll-Like Receptor-Mediated NF-kB/AP-1 Signaling on Adsorbed Protein Layers on Polymeric Surfaces
Published on: January 7, 2020
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Nuclear BK channels regulate CREB phosphorylation in RAW264.7 macrophages.
Anna Selezneva1, Minae Yoshida1, Alasdair Gibb1
1Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
Pharmacological Reports : PR
|March 13, 2021
Summary
Nuclear large conductance voltage- and calcium-activated potassium (BK) channels regulate CREB phosphorylation in macrophages. This discovery reveals novel signaling pathways involving nuclear ion channels in innate immune cells.
Area of Science:
- Immunology
- Cell Biology
- Neuroscience
Background:
- Macrophages are key innate immune cells involved in various physiological and pathophysiological processes.
- While ion channels are known in macrophage function, their roles in intracellular membranes are less understood.
- Large conductance voltage- and calcium-activated potassium (BK) channels were unexpectedly found in locations beyond the plasma membrane in RAW264.7 macrophages.
Purpose of the Study:
- To investigate the presence and function of BK channels in intracellular locations within macrophages.
- To determine the role of nuclear BK channels in regulating cellular signaling pathways.
Main Methods:
- Immunofluorescence and Western blot analyses were employed to detect BK channel expression.
- Experiments using the BK channel inhibitor paxilline were conducted on intact macrophages and isolated nuclei.
- The impact of inhibiting Ca2+ and calmodulin-dependent kinases (CaMK) on CREB phosphorylation was assessed.
Main Results:
- Paxilline treatment increased CREB phosphorylation in resting macrophages and isolated nuclei, indicating BK channel involvement.
- Inhibition of CaMKII and CaMKIV reversed the paxilline-induced increase in CREB phosphorylation.
- These findings confirm a functional role for nuclear BK channels in regulating CREB phosphorylation.
Conclusions:
- Nuclear BK channels play a regulatory role in CREB phosphorylation within macrophages.
- The study suggests novel signaling pathways mediated by nuclear ion channels in macrophages.
- These findings necessitate considering nuclear ion channels in future research on macrophage and other cell functions.
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