RESUMO
OBJECTIVE: To explore the effects of calcium pump inhibitor thapsigargin (TG) on intracellular Ca2+ and the expression of caspase-3 protein in mouse lung fibroblast. METHODS: Mice lung fibroblast cells were divided into three groups: the blank control group,transforming growth factor-ß1 (TGF-ß1) group and TG treated group. The cells were induced by 5 ng/mL TGF-ß1 for 24 h in TGF-ß1 group and TG group,4 µmol/L TG was added in TG group for 24 h. After 48 h,the cells were collected,and the cell structure was observed by transmission electron microscope,intracellular Ca2+ level was detected with laser confocal microscope,the protein expression of caspase-3 was examined using immunohistochemistry method. RESULTS: Transmission electron microscopy showed that the cells in the blank control group had obvious nucleolus,complete organelles and less apoptosis. In TGF-ß1 group,the cell morphology was intact,chromatin was evenly distributed,and no apoptotic cells were found. In TG group,there were a large number of apoptosis of fibroblasts,chromatin clumps in nuclei and a small amount of collagen fibers. The level of Ca2+ in TGF-ß1 group was significantly lower than that in control group (P<0.05),and which in TG group was significantly higher (P<0.05 ). The protein expression of caspase-3 in TGF-ß1 group were significantly lower than that in blank control group (P<0.05),which in TG group increased obviously (P<0.05). CONCLUSION: TG could cause intracellular calcium dysregulation in mouse lung fibroblasts,increase caspase-3 protein expression and promote cell apoptosis.