Fig 2: Inhibition of AMPK by Compound C attenuates SPAG6 knockdown-mediated autophagy and apoptosis in SKM-1 cells. Cells were treated with SPAG6-shRNA lentivirus or NC-shRNA lentivirus alone, or co-treated with Compound C and NC-shRNA lentivirus or SPAG6-shRNA lentivirus. (A) Relative protein expression levels of SPAG6, LC3, Beclin1, P62, p-AMPK, p-ULK1 and p-mTOR in each group were detected using western blot analysis. (B) Relative protein expression levels of SPAG6, Bcl-2, Bax and cleaved caspase-3 in each group were detected using western blot analysis. (C) Following annexin V APC/DAPI double-staining, the total apoptosis rate of SKM-1 cells treated with NC-shRNA or SPAG6-shRNA alone and SKM-1 cells cotreated with Compound C and NC-shRNA or SPAG6-shRNA was detected using flow cytometry. The images display a representative experiment from three independent experiments. (D) Analysis of the apoptotic rate shown in (C). Data are presented as the mean ± standard deviation of three independent experiments. *P<0.05; **P<0.01 vs. NC-shRNA, #P<0.05; ##P<0.01 vs. SPAG6-shRNA. NC, negative control; shRNA, short hairpin RNA; SPAG6, sperm-associated antigen 6; LC3, microtubule-associated protein 1 light chain 3; Beclin1, autophagy-associated protein 6; p62, sequestosome 1; p, phosphorylated; AMPK, AMP-activated protein kinase; ULK1, unc-51-like autophagy activating kinase; APC, allophycocyanin; LL, lower left; UL, upper left; LR, lower right; UR, upper right; ns, not significant.

Fig 3: NaHS inhibits sepsis-induced ferroptosis in cardiomyocytes. (A) Ferroptosis regulatory protein expression levels and (B) fluorescence co-localization of BECN1 and SLC7A11 in H9c2 cells treated with 5 µg/ml LPS and 50 µmol/l NaHS. *P<0.05 vs. control; #P<0.05 vs. LPS. LPS, lipopolysaccharide; NaHS, sodium hydrosulfide; BECN1, Beclin 1; SLC7A11, solute carrier family 7 member 11; PCC, Pearson's correlation coefficient; MCC, Mander's co-localization coefficient; GPX4, glutathione peroxidase 4; p-, phosphorylated.

Fig 4: NaHS inhibits myocardial ferroptosis and improves sepsis-induced cardiomyopathy. (A) Cardiac ultrasound and cardiac function index. (B) Representative images of H&E staining of rat myocardial sections. (C) Representative images of mitochondrial transmission electron microscopy of rat myocardium. (D) Western blotting of ferroptosis- and BECN1/SLC7A11 signaling-associated protein expression levels in rat myocardial tissue. *P<0.05 vs. Sham; #P<0.05 vs. CLP. H&E, hematoxylin and eosin; CLP, cecal ligation and puncture; NaHS, sodium hydrosulfide; BECN1, Beclin 1; SLC7A11, solute carrier family 7 member 11; GPX4, glutathione peroxidase 4; p-, phosphorylated.

Fig 5: Silencing of circCPA4 repressed colony formation, migration, invasion, cell cycle progression, and promoted apoptosis and autophagy of lung cancer cells. (a and b) CircCPA4 level and linear CPA4 mRNA level were detected in A549 and NCI-H1299 cells transfected with si-NC, si-circCPA4#1, and si-circCPA4#2. (c) Cell colony formation assay was employed to assess the colony formation number in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells. (d) Wound healing assay was carried out to detect migration rate in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells. (e) A transwell assay was conducted to evaluate invasion ability in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells. (f) Flow cytometry assay was performed to examine apoptosis rate in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells. (g and h) Cell cycle distribution was analyzed in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells using flow cytometry assay. (i) Western blot assay was used to detect the protein levels of Beclin1 and p62 in si-NC or si-circCPA4#2-transfected A549 and NCI-H1299 cells. Data are presented as mean ± SD, n = 3. **p < 0.01, ***p < 0.001