[[[ Aim: ]]] To investigate the effects of active vitamin D3 on autophagy and interleukin (IL)-1β expression in Salmonella -infected intestinal epithelial cells (IECs). [[[ Methods: ]]] Caco-2 cells, NOD2 siRNA-, Atg16L1 siRNA- or vitamin D receptor (VDR) siRNA-transfected Caco-2 cells were pretreated with 1,25-dihydroxyvitamin D3 (1,25D3), and then infected by wild-type S. typhimurium strain SL1344. The conversion of LC3-I to LC3-II was detected by Western blot analysis and LC3^{+} autophagosome was analyzed by immunofluorescence. Caco-2 cells or VDR siRNA-transfected cells were pretreated with 1,25D3, and then infected by SL1344. Membrane protein and total RNA were analyzed by Western blot and RT-PCR for VDR and Atg16L1 protein and mRNA expression, respectively. Atg16L1 siRNA-transfected Caco-2 cells were pretreated by 1,25D3 and then infected with SL1344. Total RNA was analyzed by RT-PCR for IL-1β mRNA expression. [[[ Results: ]]] The active form of vitamin D, 1,25D3, showed enhanced VDR-mediated Atg16L1 mRNA expression, membranous Atg16L1 protein expression leading to enhanced autophagic LC3II protein expression and LC3 punctae in Salmonella -infected Caco-2 cells which was counteracted by Atg16L1 and VDR siRNA, but Atg16L1 mediated suppression of IL-1β expression. Thus, active vitamin D may enhance autophagy but suppress inflammatory IL-1β expression in Salmonella -infected IECs. [[[ Conclusion: ]]] Active vitamin D might enhance autophagic clearance of Salmonella infection, while modulation of inflammatory responses prevents the host from detrimental effects of overwhelming inflammation.
Vitamin D differentially regulates Salmonella-induced intestine epithelial autophagy and interleukin-1β expression
비타민 D는 살모넬라 유도 장내 상피 자가포식과 인터루킨-1β 발현을 다르게 조절한다.
[Category] 살모넬라증,
[Source] pubmed
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