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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

Barrier functions and glucose transport are deregulated in the Hnf1α mutant intestine.(A) Statistical analysis of small intestinal permeability for 51CR-EDTA and ion transport as measured by short circuit current (Isc). n = 5-6. (B) Glucose plasma concentration at 0 (before) and 5, 10, 15, 30, 60, and 120 min after administration of glucose through gastric gavage. n = 6-8. (C) Glucose plasma concentration net increase after calibration of starting glucose concentration for each group at 0. (D) Linear regression T test analysis of glucose plasma concentration between 0 and 15 min. *P<0.05; ***P<0.001.
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pone-0012378-g005: Barrier functions and glucose transport are deregulated in the Hnf1α mutant intestine.(A) Statistical analysis of small intestinal permeability for 51CR-EDTA and ion transport as measured by short circuit current (Isc). n = 5-6. (B) Glucose plasma concentration at 0 (before) and 5, 10, 15, 30, 60, and 120 min after administration of glucose through gastric gavage. n = 6-8. (C) Glucose plasma concentration net increase after calibration of starting glucose concentration for each group at 0. (D) Linear regression T test analysis of glucose plasma concentration between 0 and 15 min. *P<0.05; ***P<0.001.

Mentions: A gene expression profiling was next performed to investigate whether the loss of Hnf1α could have an impact on the intestinal gene network and epithelial associated functions. A statistical analysis (p≤0.05) predicted 317 unique mouse transcripts to be modulated between adult control and mutant jejunum samples (differential ratio ≥2.0, Table S1). To gain insight into how these modifications relate to epithelial cell functions, IPA software was utilized to categorize the down-modulated genes by biological function. This analysis identified carbohydrate metabolism, small molecule biochemistry and transport, lipid metabolism and endocrine system development as being the most important gene networks predicted to be down-modulated in the Hnf1α mutant small intestine (Table S2). Intestinal barrier function was next assessed by Ussing chamber technique since several genes involved in ion transport and barrier function were shown to be significantly altered in Hnf1α mutant. Adult Hnf1α mutant mice showed a significant 69% increase in small intestinal paracellular permeability to 51Cr-EDTA as compared to controls (Figure 5A, left panel). In addition, baseline Isc was decreased more than 52% in the small intestine of adult Hnf1α mice as compared to controls demonstrating that a decrease in active epithelial ion transport was also taking place in these animals (Figure 5A, right panel). Decrease in intestinal mucosal ion transport can impact on lumen-to-blood glucose transport [24]. In addition, Hnf1α mice displayed an important down-regulation of G6PC and glucose-6-phosphate transporters (Table S1), both direct targets for Hnf1α transcriptional action [25], [26]. In order to test whether intestinal epithelial cells were affected in their capacity to deliver blood glucose from intestinal luminal content, we undertook standardized oral administration of D-glucose in overnight fasted Hnf1α mutant and control mice. As previously reported [15], the basal blood glucose concentration was significantly higher in Hnf1α mutant as compared to control mice (Figure 5B). Blood glucose levels peaked at 15–30 min after glucose administration and thereafter declined in both Hnf1α mutant and control mice (Figure 5B). However, the rate of plasma glucose delivery during the first 15 min following gastric glucose administration was significantly lowered by more than 43.3% in Hnf1α mutant when compared to control mice (Figure 5C–D).


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)

Barrier functions and glucose transport are deregulated in the Hnf1α mutant intestine.(A) Statistical analysis of small intestinal permeability for 51CR-EDTA and ion transport as measured by short circuit current (Isc). n = 5-6. (B) Glucose plasma concentration at 0 (before) and 5, 10, 15, 30, 60, and 120 min after administration of glucose through gastric gavage. n = 6-8. (C) Glucose plasma concentration net increase after calibration of starting glucose concentration for each group at 0. (D) Linear regression T test analysis of glucose plasma concentration between 0 and 15 min. *P<0.05; ***P<0.001.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2927538&req=5

pone-0012378-g005: Barrier functions and glucose transport are deregulated in the Hnf1α mutant intestine.(A) Statistical analysis of small intestinal permeability for 51CR-EDTA and ion transport as measured by short circuit current (Isc). n = 5-6. (B) Glucose plasma concentration at 0 (before) and 5, 10, 15, 30, 60, and 120 min after administration of glucose through gastric gavage. n = 6-8. (C) Glucose plasma concentration net increase after calibration of starting glucose concentration for each group at 0. (D) Linear regression T test analysis of glucose plasma concentration between 0 and 15 min. *P<0.05; ***P<0.001.
Mentions: A gene expression profiling was next performed to investigate whether the loss of Hnf1α could have an impact on the intestinal gene network and epithelial associated functions. A statistical analysis (p≤0.05) predicted 317 unique mouse transcripts to be modulated between adult control and mutant jejunum samples (differential ratio ≥2.0, Table S1). To gain insight into how these modifications relate to epithelial cell functions, IPA software was utilized to categorize the down-modulated genes by biological function. This analysis identified carbohydrate metabolism, small molecule biochemistry and transport, lipid metabolism and endocrine system development as being the most important gene networks predicted to be down-modulated in the Hnf1α mutant small intestine (Table S2). Intestinal barrier function was next assessed by Ussing chamber technique since several genes involved in ion transport and barrier function were shown to be significantly altered in Hnf1α mutant. Adult Hnf1α mutant mice showed a significant 69% increase in small intestinal paracellular permeability to 51Cr-EDTA as compared to controls (Figure 5A, left panel). In addition, baseline Isc was decreased more than 52% in the small intestine of adult Hnf1α mice as compared to controls demonstrating that a decrease in active epithelial ion transport was also taking place in these animals (Figure 5A, right panel). Decrease in intestinal mucosal ion transport can impact on lumen-to-blood glucose transport [24]. In addition, Hnf1α mice displayed an important down-regulation of G6PC and glucose-6-phosphate transporters (Table S1), both direct targets for Hnf1α transcriptional action [25], [26]. In order to test whether intestinal epithelial cells were affected in their capacity to deliver blood glucose from intestinal luminal content, we undertook standardized oral administration of D-glucose in overnight fasted Hnf1α mutant and control mice. As previously reported [15], the basal blood glucose concentration was significantly higher in Hnf1α mutant as compared to control mice (Figure 5B). Blood glucose levels peaked at 15–30 min after glucose administration and thereafter declined in both Hnf1α mutant and control mice (Figure 5B). However, the rate of plasma glucose delivery during the first 15 min following gastric glucose administration was significantly lowered by more than 43.3% in Hnf1α mutant when compared to control mice (Figure 5C–D).

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