Cobalt protoporphyrin

Astaxanthin, cobalt protoporphyrin (CoPP, an inducer of HO-1), and LPS (from Escherichia coli 026: B6) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Tin protoporphyrin IX (SnPP, an inhibitor of HO-1) was obtained from MedChemExpress (Monmouth Junction, NJ, USA). Rabbit anti-mouse β-actin, rabbit anti-mouse HO-1, and goat anti-rabbit IgG-horseradish peroxidase (HRP) were sourced from Bioworld (St. Louis Park, MN, USA). Recombinant mouse GM-CSF and interleukin-4 (IL-4) were obtained from Peprotech (Rocky Hill, NJ, USA). RPMI 1640 medium and fetal bovine serum (FBS) were sourced from Thermo Fisher Scientific (Waltham, MA, USA). Streptomycin and penicillin were obtained from Invitrogen (Grand Island, NY, USA).

Astaxanthin (mol wt 596.84), LPS derived from Escherichia coli 026: B6, FITC-Dextran (mol wt 40,000) and Cobalt protoporphyrin (CoPP, a HO-1 inducer) were from Sigma-Aldrich. Alexa Fluor 647-Dextran (mol wt 10,000) was from Thermo Fisher. Carboxyfluorescein succinimidylester (CFSE) and RPMI 1640 medium were from Invitrogen. Fetal bovine serum (FBS) was from Hyclone. Recombinant CCL19, GM-CSF, and IL-4 were from Peprotech. CCK-8 kit was from Beyotime. CD4⁺ T cell isolation kit was from Miltenyi Biotech. Fluorescent-labeled anti-mouse mAbs, PerCP-Cy5.5 CD69, FITC-MHCII, PE-CD40, PE-CD80, FITC-CD86, PE-CCR7 or respective isotype controls, were from BD PharMingen. Alexa Fluor 647 HO-1 or respective isotype was from Abcam. PE-Nrf2 or respective isotype was from Cell Signaling Technology. Tin protoporphyrin IX (SnPP, a HO-1 inhibitor) was from MedChemExpress.

Cobalt protoporphyrin, ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), nitroblue tetrazolium (NBT), curcumin, FeSO₄, CORM, RuCL₃ and 5‐bromo‐4‐chloro‐3‐indolyl phosphate (BCIP) were purchased from Sigma (St. Louis, MO). All chemicals were dissolved in dimethyl sulfoxide (DMSO), and the final concentration of DMSO in each treatment was <0.5%. Antibodies of total PERK (tPERK; sc‐32577), HO‐1 (sc‐7695) and α‐tubulin (α‐Tub; sc‐5286) were obtained from Santa Cruz Biotechnology (Santa Cruz, CA). Antibodies of phosphorylated PERK (Thr980; pPERK; #5683), poly(ADP) ribose polymerase (PARP; #9542), and binding immunoglobulin protein (BiP)/Grp78 proteins were obtained from Cell Signaling Technology (Beverly, MA). Antibody of caspase‐3 protein (Img‐144A) was purchased from IMGENEX (San Diego, CA). Antibodies of HSP70 (#610608), HSP90 (#610419), were obtained from BD Biosciences. Antibodies of total eIF‐2α (teIF‐2α; ab32157), phosphorylated eIF‐2α (Ser51; peIF‐2α; ab32157) were obtained from abcam (Eugene). Small interfering (si)RNA of HO‐1 and control siRNA, were obtained from Santa Cruz Biotechnology.