Caspase-3-dependent Cell Death in B lymphocyte Caused by Pseudomonas aeruginosa Pyocyanin

Objective: The aim of this study was to investigate cellular responses of B lymphocyte to the exposure of pyocyanin and the role of caspase-3 in its molecular mechanism. Methods: B lymphocytes (Raji cells) were cultured overnight prior to the experiments. Cell culture in five replications were then exposed to various concentrations of pyocyanin and incubated for 24 h in antibiotics-free medium. MTT assay was performed to analyze the cytotoxicity effect of pyocyanin. In separated experiments, the cells were cultured with pyocyanin and addressed for cell morphological analysis using phase contrast microscope. To study the mechanism involved in pyocyanin-induced cellular damage, immunocytochemical analysis was run for the identification of active caspase-3 protein expression. Results: The results of this study showed that cell viability was decreased in pcyocyanin-treated groups. Statistical analysis using ANOVA (p < 0.05) demonstrated significant different between groups with significant value of 0.000. Pyocyanin induced cell death on B lymphocyte in dose-dependent manner. Nuclear fragmentation was observed in pyocyanin-induced cell death; furthermore, caspase-3 was expressed clearly in cell cytoplasm after 24 h incubation. Conclusion: It is concluded that pyocyanin is capable of inducing cell death on B lymphocyte. Caspase-3 may play important role in the molecular mechanism of pyocyanin-induced cell death.DOI: 10.14693/jdi.v22i2.40