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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 results in disturbed crypt-villus architecture.Haematoxylin and eosin stained micrographs of the jejunum (A) and the ileum (B) of 4-month-old mice. Bar = 50 µm. Statistical analysis of villus (C) and crypt length (D) of jejunum and ileum of 1-month and 4-month-old mice. n = 3; total of 99-120 villi and 120 crypts. *P<0.05; ***P<0.001.
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pone-0012378-g002: Loss of Hnf1α results in disturbed crypt-villus architecture.Haematoxylin and eosin stained micrographs of the jejunum (A) and the ileum (B) of 4-month-old mice. Bar = 50 µm. Statistical analysis of villus (C) and crypt length (D) of jejunum and ileum of 1-month and 4-month-old mice. n = 3; total of 99-120 villi and 120 crypts. *P<0.05; ***P<0.001.

Mentions: A mouse Hnf1α knockout colony was generated by breeding the previously reported Hnf1α mutant strain in which Hnf1α gene expression was inactivated with the removal of the first exon that resulted in the abolition of Hnf1α gene transcription [14]. As previously reported, Hnf1α mutant mice displayed a critical reduction in their growth during post-natal development that was maintained during adulthood (data not shown). We observed that ∼25% of the mutant died during the first 36 h after birth. Total RNA and protein isolated from the jejunum and subjected to RT-PCR and Western showed that mutant mice did not produce significant levels of wild-type Hnf1α mRNA (Figure 1A) and protein (Figure 1B). Macroscopic analysis of intestinal morphology in young Hnf1α mutant pups did not reveal significant difference with control littermates. However, the intestine of adult Hnf1α mutant animals was longer and markedly expanded (Figure 1C) despite the fact these mutant mice were significantly reduced in size as compared with those of control littermates. Statistical analysis indicated a significant increase of 1.33-fold in length (Figure 1D), 1.20-fold in relative weight per length (Figure 1E) and 2.02-fold in relative weight to total body weight (Figure 1F) of the small intestines of 4 month-old mutant mice compared with those of control littermates. Significant but less prominent increases in the length and relative weight of the small intestine were also observed in 1 month old mutant animals as compared with those of control littermates (Figure 1D and F). Hematoxylin and eosin staining of jejunum and ileum sections revealed abnormal branching of the villi in the mutant animals (Figure 2A and B, right panels), a feature that was first observed at 1 month-old to become more frequent in the adult intestinal mucosa. A significant 11% decrease of jejunum villi length was observed in 1 month-old Hnf1α mutant mice as compared to control mice (Figure 2C, left panel). In opposition, a significant 23.6% increase of ileum villi length was observed in 4 month-old Hnf1α mutant mice as compared to control mice (Figure 2C, right panel). Jejunum and ileum crypts length was significantly increased (10.2% at 1 month and 20.3% at 4 months for the jejunum; 16.5% at 1 month and 11.8% at 4 months for the ileum) in Hnf1α mutant mice as compared to control mice (Figure 2D). Increase in intestinal crypt proliferation, a process of crypt fission that occurs more frequently during the first 3 weeks of post-natal life to decline afterward [17], was also observed in adult mutant mice compared with those of control littermates. The intestinal crypt fission rate, calculated as the number of dividing crypts per 200 crypts per animal (Figure 3A), was significantly up-regulated more than 2.9-fold in the jejunum and 6.5-fold in the ileum (Figure 3B) in adult Hnf1α mutant mice as compared to controls. This rate did not reach significance in 1-month-old Hnf1α mutant mice (Figure 3B). A minor but significant 10% increase of the index of epithelial cell proliferation was observed in the small intestine of 1-month-old Hnf1α mutant mice as determined by BrdU incorporation (Figure 3C). This tendency was more marked (23%) in 4-month-old Hnf1α mutant mice (Figure 3C).


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 results in disturbed crypt-villus architecture.Haematoxylin and eosin stained micrographs of the jejunum (A) and the ileum (B) of 4-month-old mice. Bar = 50 µm. Statistical analysis of villus (C) and crypt length (D) of jejunum and ileum of 1-month and 4-month-old mice. n = 3; total of 99-120 villi and 120 crypts. *P<0.05; ***P<0.001.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2927538&req=5

pone-0012378-g002: Loss of Hnf1α results in disturbed crypt-villus architecture.Haematoxylin and eosin stained micrographs of the jejunum (A) and the ileum (B) of 4-month-old mice. Bar = 50 µm. Statistical analysis of villus (C) and crypt length (D) of jejunum and ileum of 1-month and 4-month-old mice. n = 3; total of 99-120 villi and 120 crypts. *P<0.05; ***P<0.001.
Mentions: A mouse Hnf1α knockout colony was generated by breeding the previously reported Hnf1α mutant strain in which Hnf1α gene expression was inactivated with the removal of the first exon that resulted in the abolition of Hnf1α gene transcription [14]. As previously reported, Hnf1α mutant mice displayed a critical reduction in their growth during post-natal development that was maintained during adulthood (data not shown). We observed that ∼25% of the mutant died during the first 36 h after birth. Total RNA and protein isolated from the jejunum and subjected to RT-PCR and Western showed that mutant mice did not produce significant levels of wild-type Hnf1α mRNA (Figure 1A) and protein (Figure 1B). Macroscopic analysis of intestinal morphology in young Hnf1α mutant pups did not reveal significant difference with control littermates. However, the intestine of adult Hnf1α mutant animals was longer and markedly expanded (Figure 1C) despite the fact these mutant mice were significantly reduced in size as compared with those of control littermates. Statistical analysis indicated a significant increase of 1.33-fold in length (Figure 1D), 1.20-fold in relative weight per length (Figure 1E) and 2.02-fold in relative weight to total body weight (Figure 1F) of the small intestines of 4 month-old mutant mice compared with those of control littermates. Significant but less prominent increases in the length and relative weight of the small intestine were also observed in 1 month old mutant animals as compared with those of control littermates (Figure 1D and F). Hematoxylin and eosin staining of jejunum and ileum sections revealed abnormal branching of the villi in the mutant animals (Figure 2A and B, right panels), a feature that was first observed at 1 month-old to become more frequent in the adult intestinal mucosa. A significant 11% decrease of jejunum villi length was observed in 1 month-old Hnf1α mutant mice as compared to control mice (Figure 2C, left panel). In opposition, a significant 23.6% increase of ileum villi length was observed in 4 month-old Hnf1α mutant mice as compared to control mice (Figure 2C, right panel). Jejunum and ileum crypts length was significantly increased (10.2% at 1 month and 20.3% at 4 months for the jejunum; 16.5% at 1 month and 11.8% at 4 months for the ileum) in Hnf1α mutant mice as compared to control mice (Figure 2D). Increase in intestinal crypt proliferation, a process of crypt fission that occurs more frequently during the first 3 weeks of post-natal life to decline afterward [17], was also observed in adult mutant mice compared with those of control littermates. The intestinal crypt fission rate, calculated as the number of dividing crypts per 200 crypts per animal (Figure 3A), was significantly up-regulated more than 2.9-fold in the jejunum and 6.5-fold in the ileum (Figure 3B) in adult Hnf1α mutant mice as compared to controls. This rate did not reach significance in 1-month-old Hnf1α mutant mice (Figure 3B). A minor but significant 10% increase of the index of epithelial cell proliferation was observed in the small intestine of 1-month-old Hnf1α mutant mice as determined by BrdU incorporation (Figure 3C). This tendency was more marked (23%) in 4-month-old Hnf1α mutant mice (Figure 3C).

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