Amitriptyline modulated Ca2+ signaling and induced Ca2+-independent cell viability in human osteosarcoma cells. (February 2018)

• Record Type: Journal Article
• Authors: Lu, T; Chou, C-T; Liang, W-Z; Kuo, C-C; Chen, I-L; Wang, J-L; Jan, C-R
• Is Part Of: Human & experimental toxicology. Volume 37:Number 2(2018)
• Page Start: 125
• Page End: 134
• Publication Date: 2018-02
• Subjects: Amitriptyline -- Ca2+ -- cytotoxicity -- endoplasmic reticulum -- human osteosarcoma cells; Toxicology -- Periodicals; 615.9
• DOI: 10.1177/0960327117693070
• Languages: English
• ISSNs: 0960-3271

Abstract

Amitriptyline is a widely used tricyclic antidepressant, which acts primarily as a serotonin–norepinephrine reuptake inhibitor. This study examined the effect of amitriptyline on Ca 2+ homeostasis and its related mechanism in MG63 human osteosarcoma cells. Amitriptyline evoked cytosolic-free Ca 2+ concentrations ([Ca 2+ ]i ) rises concentration dependently. Amitriptyline-evoked Ca 2+ entry was confirmed by Mn 2+ -induced quench of fura-2 fluorescence. This entry was inhibited by Ca 2+ entry modulators nifedipine, econazole, SKF96365, the protein kinase C (PKC) activator phorbol 12-myristate 13 acetate but was not affected by the PKC inhibitor GF109203X. In Ca 2+ -free medium, treatment with the endoplasmic reticulum Ca 2+ pump inhibitor thapsigargin (TG) inhibited amitriptyline-evoked [Ca 2+ ]i rises by 95%. Conversely, treatment with amitriptyline abolished TG-evoked [Ca 2+ ]i rises. Inhibition of phospholipase C (PLC) with U73122 inhibited amitriptyline-evoked [Ca 2+ ]i rises by 70%. Amitriptyline killed cells at 200–500 μM in a concentration-dependent fashion. Chelating cytosolic Ca 2+ with 1, 2-bis(2-aminophenoxy)ethane- N, N, N′, N′ -tetraacetic acid/AM did not reverse amitriptyline-induced cytotoxicity. Collectively, our data suggest that in MG63 cells, amitriptyline induced [Ca 2+ ]i rises by evoking PLC-dependent Ca 2+ release from the endoplasmic reticulum and Ca 2+ entry via PKC-regulated store-operated Ca 2+ entry. Amitriptyline also induced Ca 2+ -disassociated cell death.