Ch 223191

Six- to eight-week-old male hamsters were purchased from Beijing Vital River Laboratory Animal Technology Co. Ltd. (Beijing, China). Animal experiments involving SARS-CoV-2 were carried out in an animal biosafety level 4 facility using positive pressure protective clothing. The procedures were approved by the Institutional Animal Care and Use Committee of the Institute of Medical Biology, Chinese Academy of Medical Sciences (DWSP202207010). The hamsters were also divided into treatment and control groups for each SARS-CoV-2 variant, containing six hamsters in each group. The hamsters were pretreated using AhR antagonist CH223191 (10 mg/kg, Selleck) or DMSO in advance 1 day before challenging with SARS-CoV-2. For SARS-CoV-2 infection, the hamsters were inoculated intranasally with SARS-CoV-2 at a dosage of 10⁴ TCID₅₀ per hamster. After infection, the hamsters were treated with CH223191 or DMSO control once a day for 5 days, and their body weight and clinical symptoms were recorded. At 5 dpi, the hamsters were euthanized, and lung tissues were collected for real-time PCR and histopathological analysis. Tissues were homogenized, and the supernatants were used for RNA extraction.

Kynurenine was from Sigma-Aldrich (ST, USA). IFN-β and IFN-γ were purchased from PeproTech (Rocky Hill, NJ). Fludarabine (STAT1 inhibitor) and CH223191 were purchased from Selleck (Beijing, China).

The metabolites were purchased from Sigma‐Aldrich (St. Louis, MO, USA) (Table S1, Supporting Information). AHR inhibitor CH‐223191 (cat#S7711), ERK inhibitor PD0325901 (cat#S1036), and ERK inhibitor SCH772984 (cat#S7101) were purchased from Selleck (Shanghai, China). Autophagy inhibitor Chloroquine (CQ) (cat#HY‐17589A) and 3‐Methyladenine (3MA) (cat#HY‐19312) were purchased from Med Chem Express (Shanghai, China). ULK1 inhibitor MRT68921 (cat#T9142) was purchased from TargetMol (Shanghai, China). The custom‐synthesized peptide Tat‐ERK_156‐166 (KKRRQRRRYIHSANVLHR) was produced by CUSABIO (Wuhan, Hubei, China).

The SKOV3 cell line was seeded in six‐well culture plates (1 × 10⁵ cells per well) and cultured with 2 mL fresh McCoy's 5A (modified) medium. A549, U251, and U87MG cell lines were seeded in six‐well culture plates (1 × 10⁵ cells per well) and cultured with 2 mL fresh DMEM medium. The tumor culture media were collected after 48 h. The pre‐centrifuged tumor culture media were mixed with fresh RPMI 1640 medium at different ratios of 1:7, 1:3, and 1:1. THP1 Mφ was cultured with the mixed media for about 8 h for real‐time PCR to determine the transcriptional level of Il‐1β or 72 h for enzyme linked immunosorbent assay (ELISA) to detect secretion of IL‐1β in the supernatant.
THP1 Mφ was stimulated with the mixed media at a ratio of 1:1 about 8 h for real‐time PCR or 72 h for ELISA in the presence or absence of LARA (Selleck, S5400), AhRi (Selleck, CH223191), A2AR antagonist1 (Selleck, S8575), or mGluR5 antagonist (Selleck, S2645). THP1 Mφ was collected and lysed with TRIzol reagent (Sigma‐Aldrich, T9424). To detect secreted IL‐1β protein, the medium was centrifuged (800 g, 5 min) and the supernatant was collected. All samples were stored at −80°C for further use.

Benzo[a]pyrene, benzo[k]fluoranthene, bosutinib, 1,2-dithiole-3-thione, flufenamic acid, MG132, PP2, Ro-31–8220 and hydrogen peroxide were purchased from Sigma-Aldrich (Taufkirchen, Germany), BPIQII, SR11302 and T-5224 from Cayman Chemicals (Ann Arbor, MI), and CH223191, cobimetinib and glutathione from Selleckchem (Houston, TX). Marimastat was purchased from Santa Cruz Biotechnology (Dallas, TX) and PD153035 from Absource Diagnostics (Munich, Germany). 3,3′,4,4′,5-Pentachlorobiphenyl (PCB126) and 2,3′,4,4′,5-pentachlorobiphenyl (PCB118) were bought from LGC Standards (Wesel, Germany) and 2,3,7,8-tetrachlorodibenzo-p-dioxin from Amchro (Hattersheim am Main, Germany). Prostaglandin D₂, AREG, TGFα and EGF were purchased from PeproTech (Rocky Hill, NY). hydrogen peroxide, glutathione and the three EGFR ligands were dissolved or diluted in water, the other compounds in DMSO. Treatment time and applied concentrations of the chemicals and human recombinant proteins is indicated in the figure legends.

Human biological samples were sourced ethically, and their research use was in accord with the terms of the informed consents. Human lung microvasculature endothelial cells (HMVEC-L) were obtained from Lonza (Cat no. cc-2527). Human endothelial cell cultures were grown at 37°C in Endothelial Cell Growth Media 2 (PromoCell) with 5% CO₂. Cultures were treated with the AHR agonist FICZ (Enzo, 250 nM) or AHR antagonist CH-223191 (Selleck, 3 μM) for 24 hours. Endothelial cells were lysed in 350 μl of RLT + β-mercaptoethanol for RNA extraction.