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Acetylcholine agonists stimulate mitogen‐activated protein kinase in oligodendrocyte progenitors by muscarinic receptors
Author(s) -
Larocca Jorge N.,
Almazan Guillermina
Publication year - 1997
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19971201)50:5<743::aid-jnr11>3.0.co;2-2
Subject(s) - mapk/erk pathway , muscarinic acetylcholine receptor , microbiology and biotechnology , protein kinase c , carbachol , muscarinic acetylcholine receptor m3 , protein kinase a , chemistry , mitogen activated protein kinase , biology , muscarinic acetylcholine receptor m2 , signal transduction , endocrinology , medicine , kinase , receptor , biochemistry , stimulation
Oligodendrocytes, the myelin‐producing cells of the central nervous system, express muscarinic acetylcholine receptors (mAChR). Activation of this neurotransmitter receptor by the stable acetylcholine analog carbachol (CCh) triggers transducing events, modulating c‐fos expression and cellular proliferation. To elucidate the signal transduction pathways involved in the transmission of these cellular events, we examined the ability of CCh to activate mitogen‐activated protein kinase (MAPK) in primary cultures of oligodendrocyte progenitors prepared from newborn rat brain. CCh produced a concentration‐ and time‐dependent increase in MAPK activity (predominantly the p42 mapk or ERK2) as determined by in‐gel MBP kinase assays. Using the non‐selective muscarinic antagonist atropine we determined that MAPK‐activation by CCH is mediated by muscarinic receptors. In the presence of PD098059, a specific inhibitor of MAPK kinase (MEK), MAPK activity was blocked. Similarly, the presence of extracellular calcium was required for CCh‐mediated MAPK activation. To further elucidate the mechanisms involved in MAPK activation by CCh, the role of PKC was studied. In cells in which protein kinase had been downregulated by chronic treatment with 12‐O‐tetradecanoylphorbol 13‐acetate (TPA), the effect of carbachol on MAPK activation was maintained. In contrast, the response to CCh was blocked by the PKC inhibitors H7 and bisindolylmaleimide GF109203X. Our results suggest that MAPK is implicated in the transmission of the signal for mACh receptors and involves a TPA‐insensitive PKC pathway. Further work is required to define the upstream and downstream events which result in CCh‐mediated MAPK activation and proliferation of oligodendrocyte progenitors. J. Neurosci. Res. 50:743–754, 1997. © 1997 Wiley‐Liss, Inc.