SN50 alleviates CTSB-mediated pyroptosis in VSMCs.

(A) Representative images of Hoechst 33342 (blue) and propidium iodide (PI, red) staining in VSMCs (scale bar: 100 μm). (B) Representative western blots of pyroptosis indicators (NLRP3, ASC, cleaved caspase-1 p10 [active caspase-1 subunit], GSDMD-N, IL-18, IL-1β) in VSMCs. (C) Quantification of PI-positive cell percentages. (D) Quantification of lactate dehydrogenase (LDH) activity. (E) Quantification of IL-1β secretion using an enzyme-linked immunosorbent assay. (F–H) Quantification of protein level in VSMCs: (F) NLRP3, (G) ASC, (H) caspase-1 p10, (I) GSDMD-N, (J) IL-1β, and (K) IL-18. Data are presented as means ± SEM. n = 3, *P<0.05, **P<0.01, ***P<0.001, and ****P<0.0001. CTRL: Lv-CTSB + ox-LDL; PBS: Lv-CTSB + ox-LDL + PBS; SN50: Lv-CTSB + ox-LDL + SN50 (75 μg/ml); CTSB: cathepsin B; NLRP3: NOD-like receptor protein 3; GSDMD-N: N-terminal gasdermin D; ASC: apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain; IL: interleukin; ox-LDL: oxidized low-density lipoprotein; VSMCs: vascular smooth muscle cells.