Effect of Heat Shock on Intracellular Calcium Mobilization in Neuroblastoma × Glioma Hybrid Cells |
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Authors: | Shigenori Katayama Hisato Shuntoh Shogo Matsuyama Chikako Tanaka |
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Institution: | Department of Pharmacology, Kobe University School of Medicine, Kobe University, Kobe, Japan;Department of Occupational Therapy, School of Allied Medical Sciences, Kobe University, Kobe, Japan |
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Abstract: | Abstract: The effect of heat shock on agonist-stimulated intracellular Ca2+ mobilization and the expression of heat shock protein 72 (hsp72) in neuroblastoma × glioma hybrid cells (NG 108–15 cells) were examined. Hsp72 was expressed at 6 h after heat shock (42.5°C, 2 h), reached a maximum at 12 h, and decreased thereafter. Bradykinin-induced Ca2+], rise was attenuated to 28% of control by heat shock at 2 h after heat shock, and reversion to the control level was seen 12 h later. When the cells were treated with quercetin or antisense oligodeoxyribonucleotide against hsp72 cDNA, the synthesis of hsp72 was not induced by heat shock, whereas bradykinin-induced Ca2+]i rise was abolished and the Ca2+]i rise was not restored. Recovery from this stressed condition was evident when cells were stimulated by the Ca2+-ATPase inhibitor thapsigargin, even in the presence of either quercetin or antisense oligodeoxyribonucleotide. Inositol 1,4,5-trisphosphate (IP3) production was not altered by heat shock at 12 h after heat shock, whereas IP3 receptor binding activity was reduced to 45.3%. In the presence of quercetin or antisense oligodeoxyribonucleotide, IP3 receptor binding activity decreased and reached 27.2% of the control 12 h after heat shock. Our working thesis is that heat shock transiently suppresses the IPs-mediated intracellular Ca2+ signal transduction system and that hsp72 is involved in the recovery of bradykinin-induced Ca2+]i rise. |
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Keywords: | Heat shock protein (hsp) hsp72 NG 108–15 Intracellular Ca2+ Inositol 1 4 5-trisphosphate |
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