Anandamide-induced Ca2+ elevation leading to p38 MAPK phosphorylation and subsequent cell death via apoptosis in human osteosarcoma cells.
The effect of anandamide on human osteoblasts is unclear. This study examined the effect of anandamide on viability, apoptosis, mitogen-activated protein kinases (MAPKs) and Ca2+ levels in MG63 osteosarcoma cells. Anandamide at 50-200 microM decreased cell viability via apoptosis as demonstrated by propidium iodide staining and activation of caspase-3. Immunoblotting suggested that anandamide induced expression of ERK, JNK and p38 MAPK. Anandamide-induced cell death and apoptosis were reversed by SB203580, but not by PD98059 and SP600125, suggesting that anandamide's action was via p38 MAPK, but not via ERK and JNK. Anandamide at 1-100 microM induced [Ca2+]i increases. Removal of extracellular Ca2+ decreased the anandamide response, indicating that anandamide induced Ca2+ influx and Ca2+ release. Chelation of intracellular Ca2+ with BAPTA reversed anandamide-induced cell death and p38 MAPK phosphorylation. Collectively, in MG63 cells, anandamide induced [Ca2+]i increases which evoked p38 MAPK phosphorylation. This p38 MAPK phosphorylation subsequently activated caspase-3 leading to apoptosis.
Hsu
Shu-Shong
SS
Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
Huang
Chun-Jen
CJ
Cheng
He-Hsiung
HH
Chou
Chiang-Ting
CT
Lee
Hsiao-Ying
HY
Wang
Jue-Long
JL
Chen
I-Shu
IS
Liu
Shiuh-Inn
SI
Lu
Yih-Chau
YC
Chang
Hong-Tai
HT
Huang
Jong-Khing
JK
Chen
Jin-Shyr
JS
Jan
Chung-Ren
CR
D017209:Apoptosis / Q000187:drug effects; D001095:Arachidonic Acids / Q000633:toxicity*; D002118:Calcium / Q000378:metabolism; D063385:Cannabinoid Receptor Modulators / Q000633:toxicity*; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D063388:Endocannabinoids; D006801:Humans; D012516:Osteosarcoma; D010766:Phosphorylation; D053284:Polyunsaturated Alkamides / Q000633:toxicity*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D001095:Arachidonic Acids; D063385:Cannabinoid Receptor Modulators; D002614:Chelating Agents; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; D002118:Calcium; C078814:anandamide