Ionotropic glutamate receptors expressed in human retinoblastoma Y79 cells.
Mammalian retinal photoreceptors and pinealocytes have common characteristic that they secrete melatonin and L-glutamate as chemical transmitters. Although pinealocytes express glutamate receptors and receive glutamate signals, whether or not photoreceptors express glutamate receptors is unknown. Here, we investigated the expression of the glutamate receptors in cultured Y79 clonal human retinoblastoma cells, as model systems of photoreceptors. Reverse transcription-polymerase chain reaction (RT-PCR) analysis indicated that GluR1, GluR5, GluR7, EAA2, NR1, NR2A and NR2D mRNAs were present in the cultured cells. Northern analysis confirmed the presence of GluR7, EAA2, NR1, NR2A and NR2D mRNAs, while other mRNAs were under the detection limit. Addition of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or kainate increases intracellular (Ca(2+)) in Fura-2 loaded cells, which is blocked by 6-cyano-7-nitroquinoxaline-2,3-dione. N-methyl-D-aspartate also increases intracellular (Ca(2+)). These results demonstrated the presence of functional ionotropic receptors in Y79 cells.
Takeda
M
M
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Okayama University, 700-8530, Okayama, Japan.
Haga
M
M
Yamada
H
H
Kinoshita
M
M
Otsuka
M
M
Tsuboi
S
S
Moriyama
Y
Y
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005456:Fluorescent Dyes; D016257:Fura-2; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D007608:Kainic Acid / Q000378:metabolism / Q000494:pharmacology; D016202:N-Methylaspartate / Q000378:metabolism / Q000494:pharmacology; D020419:Photoreceptor Cells, Vertebrate / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis*; D017470:Receptors, Glutamate / Q000096:biosynthesis* / Q000235:genetics; D012175:Retinoblastoma / Q000378:metabolism* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000378:metabolism / Q000494:pharmacology
D018691:Excitatory Amino Acid Antagonists; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D017470:Receptors, Glutamate; D016202:N-Methylaspartate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D007608:Kainic Acid; D002118:Calcium; D016257:Fura-2