Effect of sertraline on [Ca²⁺]_i and viability of human MG63 osteosarcoma cells

Abstract

The antidepressant, sertraline, has been shown to have diverse in vitro effects. This study examined whether sertraline altered [Ca²⁺]_i in MG63 human osteosarcoma cells by using fura-2 as a Ca²⁺-sensitive fluorescent dye. At 50–200 µM, sertraline induced a [Ca²⁺]_i rise in a concentration-dependent manner. Ca²⁺ response was decreased by removing extracellular Ca²⁺, suggesting that Ca²⁺ entry and release contributed to the [Ca²⁺]_i signal. Sertraline-induced Ca²⁺ entry was inhibited by nifedipine, La³⁺, Gd³⁺, and SK&F96365. When extracellular Ca²⁺ was removed, pretreatment with the endoplasmic reticulum (ER) Ca²⁺ pump inhibitor, thapsigargin, or 2,5-di-tert-butylhydroquinone (BHQ) abolished the sertraline-evoked [Ca²⁺]_i rise. Incubation with sertraline also abolished the thapsigargin or BHQ-induced [Ca²⁺]_i rise. Inhibition of phospholipase C (PLC) with U73122 abolished the sertraline-induced [Ca²⁺]_i rise. At 20–30 µM, overnight treatment with sertraline killed cells in a concentration-dependent manner. The cytotoxic effect of sertraline was not reversed by chelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid (BAPTA). Annexin V/propidium iodide staining data demonstrate that sertraline (30 µM) evoked apoptosis. Sertraline (20 and 30 µM) also increased levels of reactive oxygen species. Together, in human osteosarcoma cells, sertraline evoked a [Ca²⁺]_i rise by inducing PLC-dependent Ca²⁺ release from the ER and Ca²⁺ entry by L-type Ca²⁺ channels and store-operated Ca²⁺ channels. Sertraline induced cell death that may involve apoptosis by mitochondrial pathways.

Keywords::

• Ca²⁺
• fura-2
• MG63
• osteosarcoma
• sertraline

Declarations of interest

This work was supported by grants from Kaohsiung Veterans General Hospital (VGHKS99-057 and VGHKS100-062 to K.L.L.).