Fig. 4: AHR is not involved in iNOS protein stability in MSCs.

To measure iNOS protein stability, MSCs were stimulated with TNF-α, IFN-γ, and IL-1β cytokines. A The ubiquitination of iNOS was measured using an immunoprecipitation assay. iNOS and β-ACTIN were used for input and loading control. B A concentration of 10 μM chloroquine (CQ) was co-treated with three cytokines for 24 h. The levels of iNOS protein were determined using western blotting. C, D 2 μM MG132 was administered for 3 h one day after cytokine stimulation. iNOS protein levels were determined by immunofluorescence staining and western blotting, respectively. All experiments were performed at least twice, and consistent results were obtained.