Sodium metasilicate solution

VUAA1 (N-(4-ethylphenyl)-2-((4-ethyl-5-(3-pyridinyl)-4H-1,2,4-triazol-3-yl)thio)acetamide) was synthesized by the group “Mass Spectrometry/Proteomics” of the Max Planck Institute for Chemical Ecology (Jena, Germany). Ethyl hexanoate (99%, Sigma-Aldrich), L-Cysteine hydrochloride (Cat. Nr. C1276, Sigma-Aldrich), Papain (Cat. Nr. 5125, Calbiochem, San Diego, CA, United States), cOmplete protease inhibitor cocktail (Cat. Nr. 04693116001, Roche, Basel, Switzerland), methanol (≥99.5%, Roth) HCl (≥32%, Sigma-Aldrich), H₂SO₄ (95∼97%, Sigma-Aldrich), sodium metasilicate solution (Cat. Nr. 13729, Sigma-Aldrich), low Ca²⁺-Schneider’s medium (Cat. Nr. S9895, Sigma-Aldrich), Benzaldehyde (Acros Organics, NJ, United States) were used in following experiments.

Chloroquine (CQ) was purchased from Sigma-Aldrich (St. Louis, MO, USA). Bafilomycin A1 (Baf A1) was purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Cell Counting Kit-8 (CCK-8) was purchased from Dojindo Molecular Technologies (Shanghai, China). LC3 (#3868), HDAC6 (#7612), acetyl-α-tubulin (#5335), and α-tubulin (#2125) primary antibodies were purchased from Cell Signaling Technology (Danvers, MA, USA). SQSTM1/p62 (#ab56416), LAMP1 (#ab24170), and LAMP2 (#ab13524) primary antibodies were purchased from Abcam (Cambridge, UK). GAPDH (#60004-1-lg), VAMP8 (#15546-1-AP), SNAP29 (#12704-1-AP), and STX17 (#17815-1-AP) primary antibodies were purchased from Proteintech Group (Boston, MA, USA). The second antibodies (peroxidase-conjugated goat anti-rabbit IgG and peroxidase-conjugated goat anti-mouse IgG) were purchased from Yeasen Biotechnology (Shanghai, China). The sodium metasilicate solution was prepared as previously reported at a stock solution of high concentration (100 mM) with some modification [23 (link), 24 (link)]. In brief, sodium metasilicate solution (Sigma-Aldrich, #338443) was diluted into alpha-MEM to prepare a stock solution. The pH was adjusted using HCl to a physiological range (pH about 7.4) before 10% fetal bovine serum (FBS; ScienCell, Carlsbad, CA, USA) was added.