Journal
NEUROSCIENCE
Volume 167, Issue 3, Pages 665-677Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.neuroscience.2010.02.062
Keywords
endothelins; ET-1/ET3; endothelin receptors; activated microglia; ischemia; rats
Categories
Funding
- National Natural Science Foundation of China, P R China [30760093]
Ask authors/readers for more resources
We reported previously that amoeboid microglial cells (AMC) in the developing brain exhibited endothelins (ETs) expression which diminished with advancing age and was undetected in microglia in the more mature brain. This study sought to explore if microglia in the adult would be induced to express ETs in altered conditions. By immunofluorescence microscopy, ETs and endothelin (ET)-B receptor were undetected in microglial cells in sham-operated and normal control rats. However, in adult rats subjected to middle cerebral artery occlusion (MCAO), lectin labeled activated microglia which occurred in large numbers in the marginal zones in the ischemic cortex at 3 days and 1 week intensely expressed ETs specifically endothelin (ET)-1 and ET-B receptor; ET-3 and ET-A receptor were absent in these cells. By RT-PCR and ELISA, ET-1 and -3 mRNA and protein expression level was progressively increased in the ischemic cerebral cortex after MCAO compared with the controls. ET-A and ET-B receptor mRNA and protein levels were concomitantly up-regulated. It is suggested that increased release of ET-1 following MCAO by massive activated microglia can exert an immediate constriction of local blood vessels bearing ET-A receptor. ET-1 may also interact with activated microglia endowed with ET-B receptor via an autocrine manner that may be linked to chemokines/cytokines production. ET-1, ET-3 and ET-B receptor were also localized in reactive astrocytes along with some oligodendrocytes. We conclude that activated microglia together with other glial cells in the marginal zone after MCAO are the main cellular source of ETs that may be involved in regulation of vascular constriction and glial chemokines/cytokines production. However, dissecting the role of individual component of the endothelin system in the various glial cells, notably activated microglia, would be vital in designing of an effective therapeutic strategy for clinical treatment of stroke in which microglial cells have been implicated. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available