Ca 2+ Signaling and Cell Death Induced by Protriptyline in HepG2 Human Hepatoma Cells

• Published in: Journal of biochemical and molecular toxicology 2016-11, Vol.30 (11), p.539-547
• Main Authors: Wang, Jue-Long, Chou, Chiang-Ting, Liu, Kang, Liang, Wei-Zhe, Cheng, Jin-Shiung, Chang, Hong-Tai, Chen, I-Shu, Lu, Ti, Kuo, Chun-Chi, Yu, Chia-Cheng, Shieh, Pochuen, Kuo, Daih-Huang, Chen, Fu-An, Jan, Chung-Ren
• Format: Article
• Language: English
• Subjects: Antidepressive Agents, Tricyclic - pharmacology; Calcium - agonists; Calcium - metabolism; Cations, Divalent; Cell Death - drug effects; Econazole - pharmacology; Egtazic Acid - analogs & derivatives; Egtazic Acid - pharmacology; Fluorescent Dyes; Fura-2; Hep G2 Cells; Humans; Hydroquinones - pharmacology; Imidazoles - pharmacology; Indoles - pharmacology; Ion Transport - drug effects; Kinetics; Maleimides - pharmacology; Manganese - pharmacology; Nifedipine - pharmacology; Protriptyline - antagonists & inhibitors; Protriptyline - pharmacology; Spectrometry, Fluorescence; Tetradecanoylphorbol Acetate - analogs & derivatives; Tetradecanoylphorbol Acetate - pharmacology; Type C Phospholipases - antagonists & inhibitors; Type C Phospholipases - metabolism
• ISSN: 1095-6670; 1099-0461
• DOI: 10.1002/jbt.21820

The effect of protriptyline on Ca physiology in human hepatoma is unclear. This study explored the effect of protriptyline on [Ca ] and cytotoxicity in HepG2 human hepatoma cells. Protriptyline (50-150 μM) evoked [Ca ] rises. The Ca entry was inhibited by removal of Ca . Protriptyline-induced Ca entry was confirmed by Mn -induced quench of fura-2 fluorescence. Except nifedipine, econazole, SKF96365, GF109203X, and phorbol 12-myristate 13 acetate did not inhibit Ca entry. Treatment with the endoplasmic reticulum Ca pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) inhibited 40% of protriptyline-induced response. Treatment with protriptyline abolished BHQ-induced response. Inhibition of phospholipase C (PLC) suppressed protriptyline-evoked response by 70%. At 20-40 μM, protriptyline killed cells which was not reversed by the Ca chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Together, in HepG2 cells, protriptyline induced [Ca ] rises that involved Ca entry through nifedipine-sensitive Ca channels and PLC-dependent Ca release from endoplasmic reticulum. Protriptyline induced Ca -independent cell death.