Effect of Cyclosporine on Apoptosis in Bronchial Epithelial Cells

Abstract

ObjectivesAmong airway complications, posttransplantation infections are related to impaired mucociliary clearance, which may represent a toxicity of cyclosporine (CsA), a potent, widely used immunosuppressive drug after organ transplantations. Since several recent studies have demonstrated CsA treatment to directly induce apoptosis in several cell types, we investigated its effects on airway cells using the human bronchial epithelial cell line BEAS-2B. MethodsProliferation was measured by using a Cell Counting Assay Kit by exposing cells to CsA (0, 10, 30, 50, or 100 μg/mL). Apoptotic cells were identified using fluorescence microscopy after 4′, 6-diamidino-2-phenylidole (DAPI) staining. Western blot analysis was performed to evaluate the contents of poly(adenosine diphosphate-ribose) polymerase (PARP), p27, Bcl-2, and caspase-3. ResultsCell viability decreased dependent on the CsA concentration: 100.00 ± 0.01% with 0 μg CsA as control; 98.65 ± 0.02% with 10 μg (P < .05 vs control); 95.41 ± 0.05% with 30 μg (P < .05 vs control); 38.84 ± 0.04% (P < .001 vs control) with 50 μg; and 15.28 ± 0.05% with 100 μg (P < .001 vs control). Apoptotic cells detected with DAPI showed chromatin condensation and nuclear fragmentation. CsA induced p27 and p53, as well as degradation of 116-kd PARP into an 89-kd fragment. ConclusionCsA induced apoptosis in human bronchial epithelial cells.