Normal goat serum (ngs)

After 48 h of treatment, mesangial cells were scraped from culture plates and transferred to collagen solubilization tubes coated with NGS buffer (Normal goat serum (NGS) (Biological Industries)/0.1 Tris-base/0.15 M NaCl/pH = 7.5). Mesangial cells were pre-treated for collagen type 1 detection by solubilization: Cells were suspended in 0.1 mg/ml pepsin diluted in 0.05 M acetic acid at 4°C for 24–48 h repeated 5 times. At the end of each solubilization, cells were centrifuged and supernatant was preserved. After five cycles, cells were centrifuged and suspended in 0.1 mg/ml pancreatic elastase in 0.1 M Tris, 0.15 M NaCl, 5 mM CaCl₂ for 24 h at 4°C, after which cells were centrifuged and supernatant was saved. Supernatant containing soluble collagen from all the solubilization cycles was further analyzed for Rat collagen type 1 by ELISA kit (Chondrex Inc., Redmond WA, USA). To determine protein content in each sample a Bradford protein assay was performed (Bio-Rad, CA, USA), and collagen type 1 was evaluated per 100 mg protein per sample.

Triton X-100 and Tween-20 were obtained from Sigma (St. Louis, MO, USA). Paraformaldehyde was obtained from Emsdiasum (Hatfield, PA, USA). Dulbecco’s modified Eagle’s medium (DMEM) was obtained from Gibco (Grand Island, NY, USA). Normal goat serum (NGS) and the supplements fetal bovine serum (FBS), L-glutamine, and penicillin-streptomycin were obtained from Biological Industries (Beit Haemek, Israel). Primary and secondary antibodies, their source, and dilutions are detailed in Table S1. XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) was obtained from Promega. Peptide arrays (BGUN_SB-002) were produced by INTAVIS Peptide Services (GmbH & Co. KG, Tübingen, Germany), composing 768 peptide sequences derived from 19 VDAC1-interacting proteins.

Fluorescein isothiocyanate (FITC), hematoxylin and eosin, PS, PE, sulforhodamine B (SRB), Triton X‐100 and Tween‐20 were obtained from Sigma (St. Louis, MO, USA). Transfection agents JetPRIME and JetPEI were procured from PolyPlus transfection (Illkirch, France). Paraformaldehyde was obtained from Emsdiasum (Hatfield, PA, USA). Dulbecco’s modified Eagle’s medium (DMEM) media were obtained from Gibco (Grand Island, NY, USA). Normal goat serum (NGS) and the supplement FBS, l‐glutamine and penicillin/streptomycin were obtained from Biological Industries (BeitHaemek, Israel). 3,3‐Diaminobenzidine (DAB) was obtained from (Vector Laboratories ImmPact‐DAB, Burlingame, CA, USA). Primary antibodies and horseradish peroxidase (HRP)‐conjugated secondary antibodies were obtained from different sources; their source, and dilutions are detailed in Table S1. Distyrylbenzene‐bis‐aldehyde (DSB‐3) was synthesized in U. H. F. Bunz’s group.
Tissue array sections (US Biomax BCN601) were obtained from US Biomax Inc., Derwood, MD, USA). Human SMAC/Diablo‐specific siRNA (si‐hSMAC‐A) was synthesized by Genepharma (Suzhou, China). Customized 768‐peptide sequences derived from 11 SMAC‐interacting proteins were arrayed on glass slides, produced by INTAVIS (Intavis Peptide Services, Tübingen, Germany). Peptides were synthesized by GL Biochem (Shanghai, China) to > 95% purity.