Patel, R. R. | Search bioRxiv

bioRxiv2020

Alcohol dependence promotes systemic IFN-γ and IL-17 responses in mice

Alcohol use disorder (AUD) is a chronic relapsing disorder characterized by an impaired ability to stop or control alcohol use despite adverse social, occupational, or health consequences. AUD is associated with a variety of physiological changes and is a substantial risk factor for numerous diseases. We aimed to characterize systemic alterations in immune responses using a mouse model of chronic intermittent alcohol exposure to induce alcohol dependence. We exposed mice to chronic intermittent ethanol vapor for 4 weeks and used multiparametric flow cytometry to analyze the expression of cytokines IFN-{gamma}, IL-4, IL-10, IL-12 and IL-17 by different immune cells in the blood, spleen and liver of alcohol dependent and non-dependent control mice. We found increases in IFN-{gamma} and IL-17 expression in a cell type- and organ-specific manner. Often, B cells and neutrophils are primary contributors to increased IFN-{gamma} and IL-17 levels while other cell types play a secondary role. We conclude that chronic alcohol exposure promotes systemic pro-inflammatory IFN-{gamma} and IL-17 responses in mice. These responses are likely important in the development of alcohol-related diseases, but further characterization is necessary to understand the initiation and effects of systemic inflammatory responses to chronic alcohol exposure.

immunology↗

bioRxiv2020

Preferential Pharmacological Inhibition of Nav1.6, but not Nav1.1, Abolishes Epileptiform Activity Induced by 4-AP in Mouse Cortical Slices

Brain isoforms of voltage-gated sodium channels (VGSCs) have distinct cellular and subcellular expression patterns as well as functional roles that are critical for normal physiology as aberrations in their expression or activity lead to pathophysiological conditions. In this study, we asked how inhibition of select isoforms of VGSCs alters epileptiform activity to further parse out the roles of VGSCs in the brain. We first determined the relative selectivity of recently discovered small molecule, aryl sulfonamide, inhibitors (ICA-121431 and Compound 801) against Nav1.1, Nav1.2, and Nav1.6 activity using whole-cell patch clamp recordings obtained from HEK293 cells. To test the effects of these inhibitors on epileptiform activity, we obtained multielectrode array (MEA) recordings from mouse cortical slices in the presence of 4-aminopyridine (4-AP) to induce epileptiform activity. We found that the ICA-121431 and Compound 801 compounds are relatively selective for Nav1.1 and Nav1.6, respectively. From the MEA recordings, we found that inhibition of Nav1.6 and Nav1.2 with 500nM of the Compound 801 compound completely abolishes ictal local field potentials induced by 4-AP, whereas inhibition of Nav1.1 with 500nM of the ICA-121431 compound had minimal effect on epileptiform activity induced by 4-AP. Due to the prominent expression of Nav1.1 in inhibitory neurons, we asked whether inhibition of Nav1.1 alone alters activity. We found that, indeed, inhibition of Nav1.1 with the ICA-121431 compound increased basal activity in the absence of 4-AP. These findings expand our current understanding of the roles of VGSC isoforms in the brain and suggest that selective targeting of Nav1.6 may be a more efficacious treatment strategy for epileptic syndromes.

neuroscience↗