101. Ca2+ Signaling and Cell Death Induced by Protriptyline in HepG2 Human Hepatoma Cells.
- Author
-
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, and Jan, Chung‐Ren
- Abstract
ABSTRACT The effect of protriptyline on Ca
2+ physiology in human hepatoma is unclear. This study explored the effect of protriptyline on [Ca2+ ]i and cytotoxicity in HepG2 human hepatoma cells. Protriptyline (50-150 μM) evoked [Ca2+ ]i rises. The Ca2+ entry was inhibited by removal of Ca2+ . Protriptyline-induced Ca2+ entry was confirmed by Mn2+ -induced quench of fura-2 fluorescence. Except nifedipine, econazole, SKF96365, GF109203X, and phorbol 12-myristate 13 acetate did not inhibit Ca2+ entry. Treatment with the endoplasmic reticulum Ca2+ 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 Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). Together, in HepG2 cells, protriptyline induced [Ca2+ ]i rises that involved Ca2+ entry through nifedipine-sensitive Ca2+ channels and PLC-dependent Ca2+ release from endoplasmic reticulum. Protriptyline induced Ca2+ -independent cell death. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF