enterocolitica WA or Y. pestis Ind195 at MOI 1 and 20, respectively, for 1 h. Following stimulation with 10 ng/ml TNF-α at 5 h post-infection, luciferase activity was measured 24 h post-infection. Results were determined from two independent experiments performed in triplicate. A ‘*” denotes that the % NF-κβ inhibition using the inhibitors was significantly different (p<0.05) compared to the no drug control (black).
The relative NF-κB inhibition by Yersinia infection was determined as a percentage of luciferase HM781-36B solubility dmso activity in bacteria-infected cells relative to luciferase activity in bacteria-free control cells. (B) THP-1 cells were pretreated with the small molecules and infected with Y. enterocolitica WA or Y. pestis Ind195 at MOI 5 and 20, respectively, for 1 h. TNF-α levels were determined by ELISA on conditioned
media collected 24 h post-infection. Results were determined from two representative independent experiments see more performed in quadruplicate. A ‘*” denotes that TNF-α release using inhibitors was significantly different (p<0.05) compared to the no drug control. Cytokine release in response to purified LPS from E. coli 055:B5 (5μg/ml, light blue) was used as a control for pro-inflammatory mediator signaling. (C) Normal HDC were pre-treated with the small molecules for 18 h prior to infection with Y. enterocolitica WA or Y. pestis KIM5-. Bacterial infection was stopped 1 h BAY 80-6946 supplier post-infection with 170 μg/ml chloramphenicol. TNF-α levels were determined by ELISA on conditioned media collected 24 h post-infection. Statistical analysis was performed on data from 3 experiments performed in quadruplicate. TNF-α release in response to all inhibitor treatments were statistically significant (p<0.05) compared to no drug controls. We also tested the effect of the small molecule TBB, an inhibitor of the CKII Megestrol Acetate serine
kinase, which functions in cell stress response, cell cycle and cell growth regulation by activation of IKK. CKII also regulates expression of HSPH1, another stress response gene identified in our shRNA screen . Similar to OSI930, pretreatment of RE-luc2P-HEK293, THP-1, and NHDC cells with TBB resulted in higher levels of NF-κB-regulated gene expression and TNF-α release compared to a no drug control, in response to both Y. enterocolitica and Y. pestis infection (Figure 3A-C, blue vs black bars). The small molecule CKI-7 was used to validate the role of SGK1 (serum and glucocorticoid-inducible kinase 1) on NF-κB-regulated gene expression in response to Yersinia infection. SGK1 is a serine/threonine kinase that functions in cellular stress response and regulates activity of the epithelial sodium channel ENaC [27, 28], a function shared with WNK1, another kinase identified from the shRNA screen. Incubation of RE-luc2P-HEK293 cells with CKI-7 resulted in increased NF-κB-mediated luciferase activity upon exposure of Y. enterocolitica and Y. pestis-infected cells to TNF-α (Figure 3A, purple vs black bars).