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Reducing small intestinal permeability attenuates colitis in the IL10 gene-deficient mouse.

Arrieta MC, Madsen K, Doyle J, Meddings J - Gut (2008)

Bottom Line: Treated animals showed a marked reduction in small intestinal permeability.At 8 weeks of age there was a significant reduction of colonic mucosal permeability and increased electrical resistance.By 17 weeks of age, secretion of tumour necrosis factor alpha (TNFalpha) from a colonic explant was significantly lower in the treated group (25.33 (SE 4.30) pg/mg vs 106.93 (SE 17.51) pg/ml in controls, p<0.01).

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Alberta, Walter C Mackenzie Health Science Ctre, Edmonton, AB, Canada.

ABSTRACT

Background: Defects in the small intestinal epithelial barrier have been associated with inflammatory bowel disease but their role in the causation of disease is still a matter of debate. In some models of disease increased permeability appears to be a very early event. The interleukin 10 (IL10) gene-deficient mouse spontaneously develops colitis after 12 weeks of age. These mice have been shown to have increased small intestinal permeability that appears early in life. Furthermore, the development of colitis is dependent upon luminal agents, as animals do not develop disease if raised under germ-free conditions.

Aims: To determine if the elevated small bowel permeability can be prevented, and if by doing so colonic disease is prevented or attenuated.

Methods: IL10 gene-deficient (IL10(-)/(-)) mice) were treated with AT-1001 (a zonulin peptide inhibitor), a small peptide previously demonstrated to reduce small intestinal permeability. Small intestinal permeability was measured, in vivo, weekly from 4 to 17 weeks of age. Colonic disease was assessed at 8 weeks in Ussing chambers, and at 17 weeks of age inflammatory cytokines and myeloperoxidase were measured in the colon. Colonic permeability and histology were also endpoints.

Results: Treated animals showed a marked reduction in small intestinal permeability. Average area under the lactulose/mannitol time curve: 5.36 (SE 0.08) in controls vs 3.97 (SE 0.07) in the high-dose AT-1001 group, p<0.05. At 8 weeks of age there was a significant reduction of colonic mucosal permeability and increased electrical resistance. By 17 weeks of age, secretion of tumour necrosis factor alpha (TNFalpha) from a colonic explant was significantly lower in the treated group (25.33 (SE 4.30) pg/mg vs 106.93 (SE 17.51) pg/ml in controls, p<0.01). All other markers also demonstrated a clear reduction of colitis in the treated animals. Additional experiments were performed which demonstrated that AT-1001 was functionally active only in the small intestine.

Conclusions: This work suggests that increased intestinal permeability may be an important aetiological event in the development of colitis in IL10(-)/(-) mice.

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Related in: MedlinePlus

(A) Histological scoring. The interleukin 10 gene-deficient (IL10−/−) mice and the animals treated with a low dose of the zonulin peptide inhibitor AT-1001 had significantly increased histological scores as compared to the wild-type mice (*p<0.05). However, the group treated with a high dose of AT-1001 had a histological score significantly lower than the untreated IL10−/− animals (**p<0.05), but this was still elevated significantly from the wild-type (WT) controls (n = 4–6). (B) Representative histology. All panels show colonic histology at 17 weeks of age. The upper panels (a, c, e, g) were taken at ×20 magnification, while the lower panels (b, d, f, h) are the same regions at ×40. Panels a/b represent tissue from the wild-type animals while panels c/d are from the IL10−/− mice. A clear inflammatory infiltrate is observed in the lamina propria of these animals. Panels e/f are from the low-dose group while g/h are from the high-dose treated animals. It can be appreciated that there is a significant reduction in the inflammatory component of the lesion observed in these animals.
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GUT-58-01-0041-f07: (A) Histological scoring. The interleukin 10 gene-deficient (IL10−/−) mice and the animals treated with a low dose of the zonulin peptide inhibitor AT-1001 had significantly increased histological scores as compared to the wild-type mice (*p<0.05). However, the group treated with a high dose of AT-1001 had a histological score significantly lower than the untreated IL10−/− animals (**p<0.05), but this was still elevated significantly from the wild-type (WT) controls (n = 4–6). (B) Representative histology. All panels show colonic histology at 17 weeks of age. The upper panels (a, c, e, g) were taken at ×20 magnification, while the lower panels (b, d, f, h) are the same regions at ×40. Panels a/b represent tissue from the wild-type animals while panels c/d are from the IL10−/− mice. A clear inflammatory infiltrate is observed in the lamina propria of these animals. Panels e/f are from the low-dose group while g/h are from the high-dose treated animals. It can be appreciated that there is a significant reduction in the inflammatory component of the lesion observed in these animals.

Mentions: A similar attenuation effect was observed histologically. These results are illustrated in fig 7. Significant inflammation was observed in the IL10−/− mice which was similar to that observed in those treated with the low dose of AT-1001. However, those animals treated with the high dose of the compound had a significant reduction in this histological score, although it was still significantly greater than the scores observed in the control animals.


Reducing small intestinal permeability attenuates colitis in the IL10 gene-deficient mouse.

Arrieta MC, Madsen K, Doyle J, Meddings J - Gut (2008)

(A) Histological scoring. The interleukin 10 gene-deficient (IL10−/−) mice and the animals treated with a low dose of the zonulin peptide inhibitor AT-1001 had significantly increased histological scores as compared to the wild-type mice (*p<0.05). However, the group treated with a high dose of AT-1001 had a histological score significantly lower than the untreated IL10−/− animals (**p<0.05), but this was still elevated significantly from the wild-type (WT) controls (n = 4–6). (B) Representative histology. All panels show colonic histology at 17 weeks of age. The upper panels (a, c, e, g) were taken at ×20 magnification, while the lower panels (b, d, f, h) are the same regions at ×40. Panels a/b represent tissue from the wild-type animals while panels c/d are from the IL10−/− mice. A clear inflammatory infiltrate is observed in the lamina propria of these animals. Panels e/f are from the low-dose group while g/h are from the high-dose treated animals. It can be appreciated that there is a significant reduction in the inflammatory component of the lesion observed in these animals.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2597688&req=5

GUT-58-01-0041-f07: (A) Histological scoring. The interleukin 10 gene-deficient (IL10−/−) mice and the animals treated with a low dose of the zonulin peptide inhibitor AT-1001 had significantly increased histological scores as compared to the wild-type mice (*p<0.05). However, the group treated with a high dose of AT-1001 had a histological score significantly lower than the untreated IL10−/− animals (**p<0.05), but this was still elevated significantly from the wild-type (WT) controls (n = 4–6). (B) Representative histology. All panels show colonic histology at 17 weeks of age. The upper panels (a, c, e, g) were taken at ×20 magnification, while the lower panels (b, d, f, h) are the same regions at ×40. Panels a/b represent tissue from the wild-type animals while panels c/d are from the IL10−/− mice. A clear inflammatory infiltrate is observed in the lamina propria of these animals. Panels e/f are from the low-dose group while g/h are from the high-dose treated animals. It can be appreciated that there is a significant reduction in the inflammatory component of the lesion observed in these animals.
Mentions: A similar attenuation effect was observed histologically. These results are illustrated in fig 7. Significant inflammation was observed in the IL10−/− mice which was similar to that observed in those treated with the low dose of AT-1001. However, those animals treated with the high dose of the compound had a significant reduction in this histological score, although it was still significantly greater than the scores observed in the control animals.

Bottom Line: Treated animals showed a marked reduction in small intestinal permeability.At 8 weeks of age there was a significant reduction of colonic mucosal permeability and increased electrical resistance.By 17 weeks of age, secretion of tumour necrosis factor alpha (TNFalpha) from a colonic explant was significantly lower in the treated group (25.33 (SE 4.30) pg/mg vs 106.93 (SE 17.51) pg/ml in controls, p<0.01).

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Alberta, Walter C Mackenzie Health Science Ctre, Edmonton, AB, Canada.

ABSTRACT

Background: Defects in the small intestinal epithelial barrier have been associated with inflammatory bowel disease but their role in the causation of disease is still a matter of debate. In some models of disease increased permeability appears to be a very early event. The interleukin 10 (IL10) gene-deficient mouse spontaneously develops colitis after 12 weeks of age. These mice have been shown to have increased small intestinal permeability that appears early in life. Furthermore, the development of colitis is dependent upon luminal agents, as animals do not develop disease if raised under germ-free conditions.

Aims: To determine if the elevated small bowel permeability can be prevented, and if by doing so colonic disease is prevented or attenuated.

Methods: IL10 gene-deficient (IL10(-)/(-)) mice) were treated with AT-1001 (a zonulin peptide inhibitor), a small peptide previously demonstrated to reduce small intestinal permeability. Small intestinal permeability was measured, in vivo, weekly from 4 to 17 weeks of age. Colonic disease was assessed at 8 weeks in Ussing chambers, and at 17 weeks of age inflammatory cytokines and myeloperoxidase were measured in the colon. Colonic permeability and histology were also endpoints.

Results: Treated animals showed a marked reduction in small intestinal permeability. Average area under the lactulose/mannitol time curve: 5.36 (SE 0.08) in controls vs 3.97 (SE 0.07) in the high-dose AT-1001 group, p<0.05. At 8 weeks of age there was a significant reduction of colonic mucosal permeability and increased electrical resistance. By 17 weeks of age, secretion of tumour necrosis factor alpha (TNFalpha) from a colonic explant was significantly lower in the treated group (25.33 (SE 4.30) pg/mg vs 106.93 (SE 17.51) pg/ml in controls, p<0.01). All other markers also demonstrated a clear reduction of colitis in the treated animals. Additional experiments were performed which demonstrated that AT-1001 was functionally active only in the small intestine.

Conclusions: This work suggests that increased intestinal permeability may be an important aetiological event in the development of colitis in IL10(-)/(-) mice.

Show MeSH
Related in: MedlinePlus