title: NMDA receptor-mediated calcium influx plays an essential role in myoblast fusion.
abstract: Ca2+ influx is known to be prerequisite for myoblast fusion during skeletal muscle differentiation. Here, we show that the N-methyl-D-aspartate (NMDA) receptor is involved in the Ca2+ influx of C2C12 myoblasts. NMDA receptor (NR) 1 and NR2D were expressed in the myoblasts during muscle differentiation. Using Ca2+ imaging analysis, Ca2+ influx through NRs was directly measured at a single-cell level. l-Glutamate increased myoblast fusion as well as intracellular Ca2+ levels, and both effects were completely blocked by MK801, a selective antagonist of NRs. Furthermore, treatment with the Ca2+ ionophore A23187 recovered MK801-mediated inhibition of myoblast fusion. These results suggest that the NRs may play an important role in myoblast fusion by mediating Ca2+ influx.
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul, 151-742, Republic of Korea.
authors.forename: Kun Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Jae-Yong
authors.initials: JY
authors.lastname: Park
authors.forename: Kyungjin
authors.initials: K
authors.lastname: Kim
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002459:Cell Fusion; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D051379:Mice; D032448:Myoblasts, Skeletal / Q000187:drug effects / Q000502:physiology*; D016202:N-Methylaspartate / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D016194:Receptors, N-Methyl-D-Aspartate; D019284:Thapsigargin
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D018691:Excitatory Amino Acid Antagonists; C121673:Gprin1 protein, mouse; C121674:Gprin2 protein, mouse; D007476:Ionophores; D009419:Nerve Tissue Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D000001:Calcimycin; D018698:Glutamic Acid; D016202:N-Methylaspartate; D019284:Thapsigargin; D016291:Dizocilpine Maleate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D002118:Calcium