RESUMEN
Background: Atherosclerosis is a chronic inflammatory disease. Pyroptosis triggers and amplifies the inflammatory response and plays an important role in atherosclerosis. Cathepsin B (CTSB) can promote atherosclerosis and activate NOD-like receptor protein 3 (NLRP3) to mediate pyroptosis. Dapagliflozin (DAPA) can inhibit cell pyroptosis to improve atherosclerosis. This study aimed to explore the effect of DAPA on oxidized low-density lipoprotein (ox-LDL)-induced pyroptosis of vascular smooth muscle cells (VSMCs) and its underlying mechanism. Objective: We aimed to investigate the effect of DAPA on ox-LDL-induced pyroptosis of VSMCs in mice and its underlying mechanism. Methods: VSMCs were transfected with CTSB-overexpressing and -silencing lentiviral vectors. VSMCs were treated with different concentrations of ox-LDL (0, 50, 100 and 150 µg/ml ). Then, Hoechst 33342/PI double staining, interleukin (IL)-1ß and lactate dehydrogenase (LDH) release assay were used to detect cell pyroptosis. Western blotting was used to detect pyroptosis indicators protein, based on which the appropriate concentration of ox-LDL was selected. After VSMCs were treated with different concentrations of DAPA (0.1 µM, 1.0 µM, 5.0 µM, 10 µM, 25 µM and 50 µM), the proliferative activity of VSMCs was detected using Cell Counting Kit-8 (CCK8) assay. After VSMCs were pretreated with different DAPA concentrations (0.1 µM, 1.0 µM, 5.0 µM and 10 µM) for 24 hours and then treated with 150 µg/mL ox-LDL for 24 hours, the effects of different concentrations of DAPA on pyroptosis of VSMCs were detected, based on which the appropriate DAPA concentration was selected. After lentivirus transfected VSMCs were treated with 150 µg/mL ox-LDL for 24 hours, the effects of overexpression and silencing of CTSB in pyroptosis were observed. On the basis of DAPA (0.1 µM)- and ox-LDL(150 µg/mL)-treated VSMCs, overexpression and silencing of CTSB were used to observe the effects of DAPA and CTSB on ox-LDL-mediated VSMCs pyroptosis. Results: (1) VSMCs stably transfected with CTSB-overexpressing and -silencing lentiviruses were obtained; 150 µg/mL was the optimal concentration of ox-LDL for inducing pyroptosis of VSMCs, and 0.1 µM was the optimal concentration of DAPA for ameliorating pyroptosis of VSMCs. (2) Ox-LDL-induced pyroptosis of VSMCs was worsened by CTSB overexpression but suppressed by CTSB silencing. (3) DAPA attenuated ox-LDL-induced pyroptosis of VSMCs through downregulating CTSB and NLRP3. (4) Overexpression of CTSB based on DAPA intervention aggravated ox-LDL-induced pyroptosis of VSMCs. Conclusion: DAPA attenuates NLRP3/caspase-1 pathway-mediated pyroptosis of VSMCs through downregulating CTSB.