Effect of β-Adrenergic Receptor Kinase 1 on the Very Rapid Phase Homologous Desensitization of PTH/PTHrP Receptors in Rat Osteoblastic Osteosarcoma Cells, ROS17/2.8
| Autor: | Chen, Xin, Nakata, Hirohisa, Baba, Hisamitsu |
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| Jazyk: | japonština |
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | 神戸大学医学部紀要. 62(1/2):1-10 |
| ISSN: | 0075-6431 |
| Popis: | PTH/PTHrP受容体におけるごく早期の受容体脱感作のメカニズムを明らかにする目的で, ROS 17/2.8細胞におけるヒトPTH(1-34) による細胞内cAMP産生に対するベータアドレナリン受容体キナーゼ1(βARK1) の影響を検討した。細胞に10^MヒトPTH(1-34) を2分間前投与した後, 10^MヒトPTH(1-34) を2分間再投与し, ヒトPTH(1-34) を一度だけ2分間投与した場合と比較した。細胞隔解液のcAMP濃度はヒトPTH(1-34)を一度だけ投与した場合に比べて約30%低下し, 同種脱感作の現象が認められた。forskolin を用いた同様の検討では同種脱感作は認められず, ヒトPTH(1-34) によるcAMP産生反応の脱感作は, PTH/PTHrP受容体を含めて adenylylcyclaseよりも上流のメカニズムが原因となっていることが示唆された。細胞にβARK1アンチセンス phosphorothioate oligo-DNAを投与してβARK1の機能を阻害すると, ヒトPTH(1-34) によるcAMP産生のごく早期の同種脱感作は抑制された。同様に, 細胞にβARK1アンチセンスmRNAを発現させてβARK1の機能を阻害すると, ヒトPTH(1-34) によるcAMP産生のごく早期の同種脱感作は抑制された。Northern blot 法でβARK1アンチセンスmRNAの発現を確認した。これらの結果から, ROS 17/2.8細胞においてPTH/PTHrP受容体の2分以内というごく早期の同種脱感作にβARK1が関与していることが示唆された。 The effect of beta-adrenergic receptor kinase 1(βARK1) on intracellular cAMP production caused by human PTH(1-34) in ROS 17/2.8 cells was examined to investigate the mechanism of homologous desensitization of PTH/PTHrP receptors in a very rapid phase. After the cells were pretreated with 10^ M hPTH(1-34) for 2 min, they were treated again with 10^ M hPTH(1-34) for 2min. The concentration of CAMP in the cell lysate decreased approximately 30% compared with that of cells treated with 10^ M hPTH(1-34) for 2min only once (homologous desenstitization) . Homologous desensitization was abscent when the cells were treated with 10^ M forskolin in the same way, which indicated that hPTH(1-34) induced desensitization of CAMP was caused by desensitization of the upper stream mechanisms than adenylylcyclase including the PTH/PTHrP receptor. When ROS 17/2.8 cells were treated with 10μM βARK1 antisense phosphorothioate oligo-DNA to block the function of βARK1, the homologous desensitization of CAMP response to hPTH(1-34) in the very rapid phase was suppressed. When βARK1 antisense mRNA was expressed in ROS 17/2.8 cells to block the function of βARK1, the homologous desensitization of CAMP response to hPTH(1-34) in the very repid phase was also suppressed. The expression of βARK1 antisense mRNA was confirmed with Northern blot analysis. These data suggest that βARK1 is involved in the PTH/PTHrP receptor homologous desensitization in the very rapid phase in ROS 17/2.8 cells. |
| Databáze: | OpenAIRE |
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