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ACTH protects mature oligodendroglia from excitotoxic and inflammation‐related damage in vitro
Author(s) -
Benjamins Joyce A.,
Nedelkoska Liljana,
Bealmear Beverly,
Lisak Robert P.
Publication year - 2013
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.22504
Subject(s) - kainate receptor , biology , melanocortin , receptor , microglia , glutamate receptor , quinolinic acid , endocrinology , nitric oxide , medicine , inflammation , melanocortin receptor , ampa receptor , pharmacology , immunology , biochemistry , amino acid , tryptophan
Corticosteroids (CS) are widely employed to treat relapses in multiple sclerosis (MS). Endogenous ACTH is a 39‐amino acid peptide that, among other functions, stimulates CS production. Exogenous ACTH 1‐39 is used to treat MS relapses, presumably by stimulating endogenous CS production. However, unlike CS, ACTH binds to melanocortin receptors, found in the central nervous system (CNS) as well as on inflammatory cells. Since glia are implicated in MS and other neurodegenerative diseases, and oligodendroglia (OL) are more sensitive to injury than other glia, we characterized the protective effects of ACTH on OL in vitro without the confounding effects of CS. Rat brain cultures containing OL, astrocytes (AS), and microglia (MG) were incubated for 1 day with potentially cytotoxic agents with or without preincubation with ACTH 1‐39. The cytotoxic agents killed 55–70% of mature OL, but caused little or no death of AS or MG at the concentrations used. ACTH protected OL from death induced by staurosporine, AMPA, NMDA, kainate, quinolinic acid, or reactive oxygen species, but did not protect against kynurenic acid or nitric oxide. The protective effects of ACTH were dose dependent, and decreased OL death induced by the different agents by 30–60% at 200 n M ACTH. We show for the first time that melanocortin 4 receptor is expressed on OL in addition to MG and AS. In summary, ACTH 1‐39 protects OL in vitro from several excitotoxic and inflammation‐related insults. ACTH may be activating melanocortin receptors on OL or alternately on AS or MG to prevent OL death. GLIA 2013;61:1206–1217