Mo1832 The Frequency and Risk Factors of Anti-Tuberculosis Therapy-Induced Hepatotoxicity

Abstract

isms by which IFNγ affects AQP1 expression in the mouse intestinal epithelium. Methods: 1. CMT93 cells (mouse cecal epithelial cell line that constitutively expresses AQP1) grown to confluence on Transwell membranes were pre-treated with a PI3K inhibitor (LY294002, 20 μM, 2 hrs) or a NFκB inhibitor (BAY-11-7082, 10 μM, 2 hrs) prior to IFNγ (10 ng/mL, 24 hrs) treatment. Protein levels for pAKT or NFκB-p65 respectively and AQP1 were determined by Western blot. 2. Further studies were performed involving CMT93 cells pretreated with either a JAK1 inhibitor (20 μM, 2 hrs) or siRNA to knock down STAT1 or STAT3 (both at 80 nM, 24 hrs), and then treated with IFNγ (10 ng/mL, 24 hrs) in serum free media. Cells were then lysed and protein levels for AQP1, as well as phosphorylated and total STAT3 were assessed by Western blot. Results: 1. CMT93 cells demonstrated a significant suppression in AQP1 protein expression after treatment with IFNγ at 24 hours. Inhibition of either PI3K or NFκB did not affect the suppression of AQP1 exerted by IFNγ, nor did siRNA knockdown of STAT1. 2. However, pre-treatment with either the JAK1 inhibitor or STAT3 siRNA, prior to IFNγ administration resulted in the amelioration of the IFNγ-induced suppression of AQP1 protein expression. Conclusions: Inflammatory cytokines present during IBD are able to influence AQP1 levels and may contribute to the water transport deficiencies associated with these diseases. In this study, the results suggest that epithelial AQP1 expression is reduced by IFNγ in CMT93 cells through unique JAK1 and STAT3 dependent, STAT1/PI3K/NFκB independent mechanisms.