Vitamin D differentially regulates Salmonella-induced intestine epithelial autophagy and interleukin-1β expression

Figure 3 Effect of 1,25D3 on Atg16L1 mRNA expressions in Salmonella-infected Caco-2 cells and involvement of vitamin D receptor in the effect. Caco-2 cells were transfected with control siRNA and vitamin D receptor (VDR) siRNA (siRNA: non-target control siRNA; siVDR: siRNA to VDR) for 48 h. The transfected cells were left uninfected (CON) or infected by wild-type S. typhimurium strain SL1344 in the absence or presence of 1,25D3. Western blots probed with antibodies against VDR and GAPDH confirmed knockdown of VDR (A). Total RNA was prepared after infection and analyzed by real-time quantitative PCR to estimate amounts of Atg16L1 transcript. The amount of Atg16L1 mRNA produced and normalized to the corresponding amount of GAPDH transcript is shown as the fold-increase over uninfected control cells (B). Results are presented as mean ± SEM for at least three determinations from independent experiments. ^aP < 0.05.