title: ProbioticBacillus amyloliquefaciensSC06 Induces Autophagy to Protect against Pathogens in Macrophages.
abstract: Probiotics are increasingly applied in popularity in both humans and animals. Decades of research has revealed their beneficial effects, including the immune modulation in intestinal pathogens inhibition. Autophagy-a cellular process that involves the delivery of cytoplasmic proteins and organelles to the lysosome for degradation and recirculation-is essential to protect cells against bacterial pathogens. However, the mechanism of probiotics-mediated autophagy and its role in the elimination of pathogens are still unknown. Here, we evaluatedBacillus amyloliquefaciensSC06 (Ba)-induced autophagy and its antibacterial activity againstEscherichia coli(E. coli) in murine macrophage cell line RAW264.7 cells. Western blotting and confocal laser scanning analysis showed that Ba activated autophagy in a dose- and time-dependent manner. Ba-induced autophagy was found to play a role in the elimination of intracellular bacteria when RAW264.7 cells were challenged withE. coli. Ba induced autophagy by increasing the expression of Beclin1 andAtg5-Atg12-Atg16complex, but not the AKT/mTOR signaling pathway. Moreover, Ba pretreatment attenuated the activation of JNK in RAW264.7 cells duringE. coliinfection, further indicating a protective role for probiotics via modulating macrophage immunity. The above findings highlight a novel mechanism underlying the antibacterial activity of probiotics. This study enriches the current knowledge on probiotics-mediated autophagy, and provides a new perspective on the prevention of bacterial infection in intestine, which further the application of probiotics in food products.
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Cardiology, Zhejiang Provincial People's Hospital Hangzhou, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Zou
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Baikui
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Biochemistry, School of Medicine, Zhejiang University Hangzhou, China.
authors.forename: Qiming
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Aikun
authors.initials: A
authors.lastname: Fu
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Yibing
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Key Laboratory of Molecular Animal Nutrition of Ministry of Education, Institute of Feed Science, College of Animal Sciences, Zhejiang University Hangzhou, China.
authors.forename: Weifen
authors.initials: W
authors.lastname: Li
keywords: Bacillus amyloliquefaciens; antibacterial activity; autophagy; pathogens; probiotics; signaling pathways