Induction of Ca 2+ signaling and cytotoxic responses of human lung fibroblasts upon an antihistamine drug oxatomide treatment and evaluating the protective effects of Ca 2+ chelating

• Published in: Fundamental & clinical pharmacology
• Main Authors: Liang, Wei-Zhe, Hsieh, Kai-Wei, Yang, Zong-Da, Sun, Gwo-Ching
• Format: Journal Article
• Language: English
• Published: England 21-10-2024
• Subjects: Ca2+ signaling; IMR‐90 cell; store‐operated Ca2+ entry; cytotoxicity; endoplasmic reticulum; oxatomide
• ISSN: 0767-3981; 1472-8206
• DOI: 10.1111/fcp.13040

Oxatomide, an antihistamine drug of the diphenylmethylpiperazine family, has anti-inflammatory effects in airway disease. Because oxatomide was shown to cause diverse physiological responses in several cell models, the impact of oxatomide on Ca
signaling and its related physiological effects has not been explored in IMR-90 human fetal lung fibroblasts.
This study assessed the effect of oxatomide on cell viability and intracellular free Ca
concentrations ([Ca
]
) and examined whether oxatomide-induced cytotoxicity through Ca
signaling in IMR-90 cells.
Cell viability was measured by the cell proliferation reagent (WST-1). [Ca
]
was measured by the Ca
-sensitive fluorescent dye fura-2.
Oxatomide (10-40 μM) concentration dependently reduced cell viability and induced [Ca
]
rises in IMR-90 cells. This cytotoxic effect was reversed by chelation of cytosolic Ca
with BAPTA-AM. In terms of Ca
signaling, oxatomide-caused Ca
entry was inhibited by modulators of store-operated Ca
channels (2-APB and SKF96365) and protein kinase C (PKC) inhibitor (GF109203X). Furthermore, oxatomide-induced Ca
influx was confirmed by Mn
-induced quench of fura-2 fluorescence. In a Ca
-free medium, preincubation with the endoplasmic reticulum Ca
pump inhibitor thapsigargin inhibited oxatomide-evoked [Ca
]
rises. Conversely, treatment with oxatomide abolished thapsigargin-induced [Ca
]
rises. Inhibition of phospholipase C (PLC) with U73122 also inhibited oxatomide-caused [Ca
]
rises.
In IMR-90 cells, oxatomide-induced cytotoxicity by preceding [Ca
]
rises involving PKC-sensitive store-operated Ca
entry and PLC-dependent Ca
release from the endoplasmic reticulum. BAPTA-AM, with its Ca
chelating effects, may be a potential compound for preventing oxatomide-induced cytotoxicity.