Calcium signaling and c-Fos gene expression via M3 muscarinic acetylcholine receptors in human T- and B-cells.
We previously showed that blood acetylcholine (ACh) originates mainly from T-lymphocytes, and that stimulation of muscarinic ACh receptors (mAChRs) induces Ca2+ oscillations and up-regulates c-fos gene expression in both T- and B-lymphocytes. In the present study, we investigated which mAChR subtypes are involved in Ca2+ signaling and c-fos gene expression in human T- (CEM) and B- (Daudi) cells. Stimulation of mAChRs with 100 microM oxotremorine-M, an M1/M3 agonist, increased levels of intracellular free Ca2+ ([Ca2+]i) and c-fos mRNA expression in both cell lines. 4-DAMP, an M3 antagonist, more effectively blocked the oxotremorine-M-induced increase in [Ca2+]i than pirenzepine and telenzepine, M1-receptor antagonists; AF-DX 116, an M2 antagonist; hexahydrosiladifenidol, a weak M3 antagonist; or hexamethonium and d-tubocurarine, nicotinic receptor antagonists. McN-A-343 (100 microM), a partial M1-receptor agonist, had no apparent effect on [Ca2+]i in either cell line. The oxotremorine-M-induced up-regulation of c-fos transcription was inhibited by 4-DAMP, but not by pirenzepine or AF-DX 116. Our findings thus suggest that ACh released from T-lymphocytes acts as an autocrine/paracrine factor, transmitting a Ca2+-dependent signal to the nuclei of T- and B-lymphocytes via M3 receptors.
Fujii
T
T
Department of Pharmacology, Kyoritsu College of Pharmacy, Tokyo, Japan.
Kawashima
K
K
D000704:Analysis of Variance; D001402:B-Lymphocytes / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects; D018679:Cholinergic Agonists / Q000494:pharmacology; D018680:Cholinergic Antagonists / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis / Q000235:genetics*; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*; D014407:Tumor Cells, Cultured
D018679:Cholinergic Agonists; D018680:Cholinergic Antagonists; D016760:Proto-Oncogene Proteins c-fos; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic