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Loss of hepatocyte-nuclear-factor-1alpha impacts on adult mouse intestinal epithelial cell growth and cell lineages differentiation.

Lussier CR, Brial F, Roy SA, Langlois MJ, Verdu EF, Rivard N, Perreault N, Boudreau F - PLoS ONE (2010)

Bottom Line: Although Hnf1alpha is crucial for pancreas and liver functions, it is believed to play a limited functional role for intestinal epithelial functions.Changes in global gene expression were also analyzed.This phenotype was associated with a decrease of the mucosal barrier function and lumen-to-blood glucose delivery.

View Article: PubMed Central - PubMed

Affiliation: Département d'Anatomie et Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.

ABSTRACT

Background and aims: Although Hnf1alpha is crucial for pancreas and liver functions, it is believed to play a limited functional role for intestinal epithelial functions. The aim of this study was to assess the consequences of abrogating Hnf1alpha on the maintenance of adult small intestinal epithelial functions.

Methodology/principal findings: An Hnf1alpha knockout mouse model was used. Assessment of histological abnormalities, crypt epithelial cell proliferation, epithelial barrier, glucose transport and signalling pathways were measured in these animals. Changes in global gene expression were also analyzed. Mice lacking Hnf1alpha displayed increased crypt proliferation and intestinalomegaly as well as a disturbance of intestinal epithelial cell lineages production during adult life. This phenotype was associated with a decrease of the mucosal barrier function and lumen-to-blood glucose delivery. The mammalian target of rapamycin (mTOR) signalling pathway was found to be overly activated in the small intestine of adult Hnf1alpha mutant mice. The intestinal epithelium of Hnf1alpha mice displayed a reduction of the enteroendocrine cell population. An impact was also observed on proper Paneth cell differentiation with abnormalities in the granule exocytosis pathway.

Conclusions/significance: Together, these results unravel a functional role for Hnf1alpha in regulating adult intestinal growth and sustaining the functions of intestinal epithelial cell lineages.

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Related in: MedlinePlus

Loss of Hnf1α leads to deregulation of enteroendocrine cell production.(A) Chromogranin A immunodetection was performed on ileum tissue sections. Representative micrographs and statistical analyses of the number of positive labeled-cells per crypt-villus axis. n = 3-4; average of 40 crypt-villus axis per mouse. (B) qRT-PCR analysis performed on total RNA extracts from 4-month-old mice (means +/- SEM). n = 5-10. *P<0.05; **P<0.01; ***P<0.001.
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pone-0012378-g007: Loss of Hnf1α leads to deregulation of enteroendocrine cell production.(A) Chromogranin A immunodetection was performed on ileum tissue sections. Representative micrographs and statistical analyses of the number of positive labeled-cells per crypt-villus axis. n = 3-4; average of 40 crypt-villus axis per mouse. (B) qRT-PCR analysis performed on total RNA extracts from 4-month-old mice (means +/- SEM). n = 5-10. *P<0.05; **P<0.01; ***P<0.001.

Mentions: The effect of Hnf1α deletion on the maturation of intestinal epithelial secretory cell lineages was next monitored. The number of goblet cells was first compared between Hnf1α mutant and control mice by alcian blue staining. The relative number of goblet cells per length units was modestly but significantly increased in the jejunum crypts of Hnf1α mutant mice and significantly decreased in the ileum villi of the same individuals (Figure 6A). However, these subtle modifications did not impact on overall gene transcript expression of goblet cell markers as revealed by qRT-PCR analyses of trefoil factor 3 and mucin 2 transcripts expression (Figure 6B). Although lysozyme staining of the Paneth cells was consistently more diffused in Hnf1α mutant crypts, a significant 40.5% increase in the number of positive cells per crypt was denoted in the Hnf1α mutant mice as compared to control mice (Figure 6C, right panel). qRT-PCR analyses showed a significant 30.6% reduction in the expression of lysozyme transcript in the Hnf1α mutant mice as compared to control mice (Figure 6D). Electron micrograph of Paneth cells confirmed abnormal cellular morphology with aberrant and disorganized granules in the Hnf1α mutant mice (Figure 6E). Thus, the number of Paneth cells was increased but these cells were less mature in Hnf1α mutant mice. The number of chromogranin A positive enteroendocrine cells per villus was significantly decreased in newborn (29%) and adult (59%) mutant mice as compared to control mice (Figure 7A). The analysis of several targets associated with enteroendocrine differentiation revealed significant modulations of chromogranin A (Chga), somatostatin (Sst), gastric inhibitory polypeptide (Gip), Ghrelin (Ghrl) and Pax6 gene transcripts expression (Figure 7B). Overall, these observations indicated that loss of Hnf1α had a significant impact on terminal differentiation of multiple intestinal epithelial cell lineages.


Loss of hepatocyte-nuclear-factor-1alpha impacts on adult mouse intestinal epithelial cell growth and cell lineages differentiation.

Lussier CR, Brial F, Roy SA, Langlois MJ, Verdu EF, Rivard N, Perreault N, Boudreau F - PLoS ONE (2010)

Loss of Hnf1α leads to deregulation of enteroendocrine cell production.(A) Chromogranin A immunodetection was performed on ileum tissue sections. Representative micrographs and statistical analyses of the number of positive labeled-cells per crypt-villus axis. n = 3-4; average of 40 crypt-villus axis per mouse. (B) qRT-PCR analysis performed on total RNA extracts from 4-month-old mice (means +/- SEM). n = 5-10. *P<0.05; **P<0.01; ***P<0.001.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2927538&req=5

pone-0012378-g007: Loss of Hnf1α leads to deregulation of enteroendocrine cell production.(A) Chromogranin A immunodetection was performed on ileum tissue sections. Representative micrographs and statistical analyses of the number of positive labeled-cells per crypt-villus axis. n = 3-4; average of 40 crypt-villus axis per mouse. (B) qRT-PCR analysis performed on total RNA extracts from 4-month-old mice (means +/- SEM). n = 5-10. *P<0.05; **P<0.01; ***P<0.001.
Mentions: The effect of Hnf1α deletion on the maturation of intestinal epithelial secretory cell lineages was next monitored. The number of goblet cells was first compared between Hnf1α mutant and control mice by alcian blue staining. The relative number of goblet cells per length units was modestly but significantly increased in the jejunum crypts of Hnf1α mutant mice and significantly decreased in the ileum villi of the same individuals (Figure 6A). However, these subtle modifications did not impact on overall gene transcript expression of goblet cell markers as revealed by qRT-PCR analyses of trefoil factor 3 and mucin 2 transcripts expression (Figure 6B). Although lysozyme staining of the Paneth cells was consistently more diffused in Hnf1α mutant crypts, a significant 40.5% increase in the number of positive cells per crypt was denoted in the Hnf1α mutant mice as compared to control mice (Figure 6C, right panel). qRT-PCR analyses showed a significant 30.6% reduction in the expression of lysozyme transcript in the Hnf1α mutant mice as compared to control mice (Figure 6D). Electron micrograph of Paneth cells confirmed abnormal cellular morphology with aberrant and disorganized granules in the Hnf1α mutant mice (Figure 6E). Thus, the number of Paneth cells was increased but these cells were less mature in Hnf1α mutant mice. The number of chromogranin A positive enteroendocrine cells per villus was significantly decreased in newborn (29%) and adult (59%) mutant mice as compared to control mice (Figure 7A). The analysis of several targets associated with enteroendocrine differentiation revealed significant modulations of chromogranin A (Chga), somatostatin (Sst), gastric inhibitory polypeptide (Gip), Ghrelin (Ghrl) and Pax6 gene transcripts expression (Figure 7B). Overall, these observations indicated that loss of Hnf1α had a significant impact on terminal differentiation of multiple intestinal epithelial cell lineages.

Bottom Line: Although Hnf1alpha is crucial for pancreas and liver functions, it is believed to play a limited functional role for intestinal epithelial functions.Changes in global gene expression were also analyzed.This phenotype was associated with a decrease of the mucosal barrier function and lumen-to-blood glucose delivery.

View Article: PubMed Central - PubMed

Affiliation: Département d'Anatomie et Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada.

ABSTRACT

Background and aims: Although Hnf1alpha is crucial for pancreas and liver functions, it is believed to play a limited functional role for intestinal epithelial functions. The aim of this study was to assess the consequences of abrogating Hnf1alpha on the maintenance of adult small intestinal epithelial functions.

Methodology/principal findings: An Hnf1alpha knockout mouse model was used. Assessment of histological abnormalities, crypt epithelial cell proliferation, epithelial barrier, glucose transport and signalling pathways were measured in these animals. Changes in global gene expression were also analyzed. Mice lacking Hnf1alpha displayed increased crypt proliferation and intestinalomegaly as well as a disturbance of intestinal epithelial cell lineages production during adult life. This phenotype was associated with a decrease of the mucosal barrier function and lumen-to-blood glucose delivery. The mammalian target of rapamycin (mTOR) signalling pathway was found to be overly activated in the small intestine of adult Hnf1alpha mutant mice. The intestinal epithelium of Hnf1alpha mice displayed a reduction of the enteroendocrine cell population. An impact was also observed on proper Paneth cell differentiation with abnormalities in the granule exocytosis pathway.

Conclusions/significance: Together, these results unravel a functional role for Hnf1alpha in regulating adult intestinal growth and sustaining the functions of intestinal epithelial cell lineages.

Show MeSH
Related in: MedlinePlus