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Increased antigen and bacterial uptake in follicle-associated epithelium induced by chronic psychological stress in rats
Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet.
Linköpings universitet, Institutionen för klinisk och experimentell medicin, Cellbiologi. Linköpings universitet, Hälsouniversitetet.
Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet.
Linköpings universitet, Institutionen för klinisk och experimentell medicin, Kirurgi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Kirurgi- och onkologicentrum, Kirurgiska kliniken i Östergötland med verksamhet i Linköping, Norrköping och Motala.
Vise andre og tillknytning
2004 (engelsk)Inngår i: Gut, ISSN 0017-5749, Vol. 53, nr 4, s. 494-500Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Background: Chronic stress affects the course of inflammatory bowel disease and experimental colitis, and may also initiate intestinal inflammation in rats.

Aim: To investigate the effects of stress on the M cell containing follicle associated epithelium, specialised in antigen uptake.

Subjects and methods: Wistar rats were submitted to acute water avoidance stress for one hour or chronic water avoidance stress for 1 hour/day for 10 consecutive days. Permeability to 51Cr-EDTA, horseradish peroxidase, and chemically killed Escherichia coli K-12 was studied in both villus and follicle associated epithelium in Ussing chambers. Segments were further examined by light, electron, and confocal microscopy.

Results: Acute stress increased horseradish peroxidase flux in villus as well as in follicle associated epithelium. Chronic stress further increased permeability to horseradish peroxidase in villus and follicle associated epithelium, in the latter by almost fourfold. Moreover, chronic stress induced over 30 times increased E coli passage in follicle associated epithelium whereas there was no significant increase in villus epithelium. Bacterial uptake was confirmed by confocal microscopy showing fluorescent bacteria penetrating and passing through the epithelial surface.

Conclusions: These results show that the barrier function of follicle associated epithelium can be modulated, and that chronic stress enhances the uptake of luminal antigens and bacteria via the follicle associated epithelium. This can increase antigen exposure in Peyer’s patches thereby having implications in the initiation of proinflammatory immune responses within the intestinal mucosa.

sted, utgiver, år, opplag, sider
2004. Vol. 53, nr 4, s. 494-500
Emneord [en]
follicle associated epithelium, M cell, Peyer’s patch, inflammatory bowel disease, stress
HSV kategori
Identifikatorer
URN: urn:nbn:se:liu:diva-14562DOI: 10.1136/gut.2003.028506OAI: oai:DiVA.org:liu-14562DiVA, id: diva2:23834
Tilgjengelig fra: 2007-07-03 Laget: 2007-07-03 Sist oppdatert: 2009-08-21
Inngår i avhandling
1. Barrier function of the Follicle-Associated Epithelium in Stress and Crohn's disease
Åpne denne publikasjonen i ny fane eller vindu >>Barrier function of the Follicle-Associated Epithelium in Stress and Crohn's disease
2007 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [sv]

Crohns sjukdom är en kronisk inflammatorisk tarmsjukdom av okänd orsak. Det tidigaste tecknet på Crohns sjukdom är mikroskopiska sår i det s.k. follikelassocierade epitelet (FAE) som täcker ansamlingar av immunceller i tarmen. FAE är specialiserat för att fånga innehåll från tarmen och transportera det till underliggande immunvävnad. Denna funktion är viktig för att inducera skyddande immunsvar, men den utgör också en ingångsväg för sjukdomsalstrande bakterier. Crohns sjukdom är associerat med ett kraftigt ökat immunsvar mot bakterier, och sjukdomsförloppet kan ändras av stress.

Det övergripande syftet med avhandlingen var att studera effekterna av stress på FAE samt att undersöka rollen av FAE vid utvecklingen av tarminflammation, särskilt vid Crohns sjukdom.

Inledningsvis studerades effekterna av psykologisk stress på FAE. Stressade råttor uppvisade ökad genomsläpplighet av bakterier efter stress, och passagen var högre i FAE än i vanligt epitel. Efterföljande experiment visade att stressförändringarna i slemhinnan regleras via kortikotropinfrisättande hormon och mastceller. Vidare visade det sig att vasoaktiv intestinal peptid kunde efterlikna stressens effekter på genomsläppligheten, och att detta kunde förhindras genom att blockera mastcellerna.

Studier av tunntarmsslemhinna från patienter med icke-inflammatorisk tarmsjukdom och friska kontroller visade en högre passage av bakterier i FAE än i vanligt epitel. Hos patienter med Crohns sjukdom var bakteriepassagen genom FAE betydligt ökad jämfört med kontroller.

Resultaten från detta avhandlingsarbete visar att stress kan förändra upptaget av bakterier från tarmen via FAE, med mekanismer som innefattar kortikotropinfrisättande hormon och mastceller. Detta har gett nya kunskaper kring regleringen av slemhinnebarriären. Vidare presenterar denna avhandling nya insikter i sjukdomsuppkomsten vid Crohns sjukdom genom att påvisa en tidigare okänd defekt i barriärfunktionen i FAE.

Abstract [en]

The earliest observable signs of Crohn’s disease are microscopic erosions in the follicle-associated epithelium (FAE) covering the Peyer’s patches. The FAE, which contains M cells, is specialised in sampling of luminal content and delivery to underlying immune cells. This sampling is crucial for induction of protective immune responses, but it also provides a route of entry for microorganisms into the mucosa. Crohn’s disease is associated with an increased immune response to bacteria, and the disease course can be altered by stress.

The overall aim of this thesis was to study the effects of stress on the FAE and elucidate the role of FAE in the development of intestinal inflammation, specifically Crohn’s disease.

Initially, rats were submitted to acute and chronic water avoidance stress to study the effects of psychological stress on the FAE. Stressed rats showed enhanced antigen and bacterial passage, and the passage was higher in FAE than in regular villus epithelium (VE). Further, stress gave rise to ultrastructural changes. Subsequent experiments revealed the stress-induced increase in permeability to be regulated by corticotropin-releasing hormone and mast cells. Furthermore, vasoactive intestinal peptide (VIP) mimicked the stress effects on permeability, and the VIP effects were inhibited by a mast cell stabiliser.

Human studies of ileal mucosa from patients with non-inflammatory disease and healthy controls showed a higher antigen and bacterial passage in FAE than in VE. In patients with Crohn’s disease, the bacterial passage across the FAE was significantly increased compared to non-inflammatory and inflammatory controls (ulcerative colitis). Furthermore, there was an enhanced uptake of bacteria into dendritic cells, and augmented TNF-α release in Crohn’s disease mucosa.

Taken together this thesis shows that stress can modulate the uptake of luminal antigens and bacteria via the FAE, through mechanisms involving CRH and mast cells. It further shows that human ileal FAE is functionally distinct from VE, and that Crohn’s disease patients exhibit enhanced FAE permeability compared to inflammatory and non-inflammatory controls.

This thesis presents novel insights into regulation of the FAE barrier, as well as into the pathophysiology of Crohn’s disease by demonstrating a previously unrecognised defect of the FAE barrier function in ileal Crohn’s disease.

sted, utgiver, år, opplag, sider
Institutionen för biomedicin och kirurgi, 2007. s. 105
Serie
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1006
Emneord
Corticotropin-releasing hormone, Crohn’s disease, 51Cr- EDTA, Escherichia coli, follicle-associated epithelium, horseradish peroxidase, human, ileum, inflammatory bowel disease, intestinal mucosa, mast cell, M cell, permeability, Peyer’s patches, rat, Ussing chamber, vasoactive intestinal peptide, villus epithelium
HSV kategori
Identifikatorer
urn:nbn:se:liu:diva-9271 (URN)978-91-85831-79-1 (ISBN)
Disputas
2007-06-08, Aulan, Hälsans Hus, Campus US, Linköpings Universitet, Linköping, 09:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2007-07-03 Laget: 2007-07-03 Sist oppdatert: 2009-08-22

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