title: Cigarette smoke and the terminal ileum: increased autophagy in murine follicle-associated epithelium and Peyer's patches.
abstract: Cigarette smoke (CS) exposure is associated with increased autophagy in several cell types, such as bronchial epithelial cells. Smoking is also an environmental risk factor in Crohn's disease, in which impairment of the autophagy-mediated anti-bacterial pathway has been implicated. So far, it is unknown whether CS induces autophagy in the gut. Here, we examined the effect of chronic CS exposure on autophagy in the follicle-associated epithelium (FAE) of murine Peyer's patches. Transmission electron microscopy revealed that the proportion of cell area occupied by autophagic vesicles significantly increased in the FAE after CS exposure. An increased number of autophagic vesicles was observed in the FAE, whereas the vesicle size remained unaltered. Besides enterocytes, also M-cells contain more autophagic vesicles upon CS exposure. In addition, the mRNA level of the autophagy-related protein Atg7 in the underlying Peyer's patches is increased after CS exposure, which indicates that the autophagy-inducing effect of CS is not limited to the FAE. In conclusion, our results demonstrate that CS exposure induces autophagy in murine FAE and in the underlying immune cells of Peyer's patches, suggesting that CS exposure increases the risk for Crohn's disease by causing epithelial oxidative damage, which needs to be repaired by autophagy.
authors.affiliation: Department of Pathology, University Hospital Ghent, 5 Blok A, De Pintelaan 185, 9000 Ghent, Belgium. Stephanie.Verschuere@ugent.be
authors.forename: Stephanie
authors.initials: S
authors.lastname: Verschuere
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Allais
authors.forename: Ken R
authors.initials: KR
authors.lastname: Bracke
authors.forename: Saskia
authors.initials: S
authors.lastname: Lippens
authors.forename: Rebecca
authors.initials: R
authors.lastname: De Smet
authors.forename: Peter
authors.initials: P
authors.lastname: Vandenabeele
authors.forename: Guy G G
authors.initials: GG
authors.lastname: Brusselle
authors.forename: Claude A
authors.initials: CA
authors.lastname: Cuvelier
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001343:Autophagy / Q000502:physiology*; D000071187:Autophagy-Related Protein 5; D000071193:Autophagy-Related Protein 7; D000071186:Beclin-1; D002908:Chronic Disease; D003424:Crohn Disease / Q000453:epidemiology / Q000473:pathology; D007082:Ileum / Q000473:pathology* / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000473:pathology* / Q000648:ultrastructure; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D010581:Peyer's Patches / Q000473:pathology* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000378:metabolism; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D051017:Apoptosis Regulatory Proteins; C495773:Atg5 protein, mouse; C502661:Atg7 protein, mouse; D000071187:Autophagy-Related Protein 5; D000071186:Beclin-1; C115010:Becn1 protein, mouse; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D014028:Tobacco Smoke Pollution; D000071193:Autophagy-Related Protein 7