Figure 1. C-176 inhibits cyclic di-nucleotide (CDN) mediated STING activation.
Inhibition of STING and TBK1 phosphorylation occurs in BV2 microglia-like cells pre-treated for 30 minutes with STING inhibitor C-176 and treated for 8 hours with 10-20µg of c-di-GMP. (A)Protein expression analysed by western blot. Densitometric analysis(B-C) was performed to quantitate expression of p-STING relative to STING and p-TBK1 relative to TBK1. Protein expression was measured as ratio of band intensity and β-actin loading control. The expression of p-STING (B) and p-TBK1 (C) was made relative to total protein expression of STING and TBK1 respectively. All data is expressed as mean ± SEM. STING phosphorylation was significantly increased following treatment with 10μg/mL (p=0010) and 20μg/mL (p<0.0001) of c-di-GMP compared to untreated vehicle. Treatment with 2μM C-176 completely ablated c-di-GMP induced phosphorylation of STING. n = 5. Significance determined by two-way ANOVA followed by a Bonferroni’s multiple comparison test within each dose of C-176. *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001