ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Corticosterone Treatment Results in Enhanced Release of Peptidergic Vesicles in Astrocytes via Cytoskeletal Rearrangements

Chatterjee, Sreejata and Sikdar, Sujit K (2013) Corticosterone Treatment Results in Enhanced Release of Peptidergic Vesicles in Astrocytes via Cytoskeletal Rearrangements. In: GLIA, 61 (12). pp. 2050-2062.

Full text not available from this repository. (Request a copy)
Official URL: http://dx.doi.org/10.1002/glia.22576

Abstract

While the effect of stress on neuronal physiology is widely studied, its effect on the functionality of astrocytes is not well understood. We studied the effect of high doses of stress hormone corticosterone, on two physiological properties of astrocytes, i.e., gliotransmission and interastrocytic calcium waves. To study the release of peptidergic vesicles from astrocytes, hippocampal astrocyte cultures were transfected with a plasmid to express pro-atrial natriuretic peptide (ANP) fused with the emerald green fluorescent protein (ANP.emd). The rate of decrease in fluorescence of ANP.emd on application of ionomycin, a calcium ionophore was monitored. Significant increase in the rate of calcium-dependent exocytosis of ANP.emd was observed with the 100 nM and 1 M corticosterone treatments for 3 h, which depended on the activation of the glucocorticoid receptor. ANP.emd tagged vesicles exhibited increased mobility in astrocyte culture upon corticosterone treatment. Increasing corticosterone concentrations also resulted in concomitant increase in the calcium wave propagation velocity, initiated by focal ATP application. Corticosterone treatment also resulted in increased GFAP expression and F-actin rearrangements. FITC-Phalloidin immunostaining revealed increased formation of cross linked F-actin networks with the 100 nM and 1 M corticosterone treatment. Alternatively, blockade of actin polymerization and disruption of microtubules prevented the corticosterone-mediated increase in ANP.emd release kinetics. This study reports for the first time the effect of corticosterone on gliotransmission via modulation of cytoskeletal elements. As ANP acts on both neurons and blood vessels, modulation of its release could have functional implications in neurovascular coupling under pathophysiological conditions of stress.

Item Type: Journal Article
Publication: GLIA
Publisher: WILEY-BLACKWELL
Additional Information: copyright for this article belongs to WILEY-BLACKWELL
Keywords: atrial natiuretic peptide; crosslinked actin networks; glucocorticoid receptor
Department/Centre: Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited: 28 Nov 2013 11:26
Last Modified: 28 Nov 2013 11:26
URI: http://eprints.iisc.ac.in/id/eprint/47836

Actions (login required)

View Item View Item