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Hyperplasia of interstitial cells of cajal in sprouty homolog 4 deficient mice.

Thys A, Vandenberghe P, Hague P, Klein OD, Erneux C, Vanderwinden JM - PLoS ONE (2015)

Bottom Line: Sprouty homolog 4 was upregulated both at the mRNA and protein level in these cells, suggesting that Sprouty homolog 4 is downstream of oncogenic KIT activation and potentially engaged in the negative feedback loop of ERK activation in this model.Here, we used KitK641E heterozygous and Sprouty homolog 4 knock out animals to quantify interstitial cells of Cajal in situ, using quantitative immunofluorescence for the receptor tyrosine kinase Kit and for phosphodiesterase 3a (PDE3A).We concluded that the lack of Sprouty homolog 4 expression leads to hyperplasia of the interstitial cells of Cajal and is functionally associated with a delayed transit time.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.

ABSTRACT
Gastrointestinal stromal tumors, which are thought to derive from interstitial cells of Cajal or their precursors, often harbor an oncogenic mutation of the KIT receptor tyrosine kinase. Sprouty homolog 4, a known negative regulator of ERK pathway, has been identified in the interstitial cells of Cajal in the KitK641E murine model of gastrointestinal stromal tumors. Sprouty homolog 4 was upregulated both at the mRNA and protein level in these cells, suggesting that Sprouty homolog 4 is downstream of oncogenic KIT activation and potentially engaged in the negative feedback loop of ERK activation in this model. Here, we used KitK641E heterozygous and Sprouty homolog 4 knock out animals to quantify interstitial cells of Cajal in situ, using quantitative immunofluorescence for the receptor tyrosine kinase Kit and for phosphodiesterase 3a (PDE3A). In the antrum of Sprouty homolog 4 knock out mice, hyperplasia of interstitial cells of Cajal was reminiscent of the KitK641E heterozygous mice antrum. Additionally, the density of interstitial cells of Cajal was higher in the colon of adult Sprouty homolog 4 knock out mice than in WT littermates, although hyperplasia seemed more severe in KitK641E heterozygous mice. Functional transit studies also show similarities between Sprouty homolog 4 knock out and KitK641E heterozygous mice, as the total transit time in 9 month old animals was significantly increased in both genotypes compared to WT littermates. We concluded that the lack of Sprouty homolog 4 expression leads to hyperplasia of the interstitial cells of Cajal and is functionally associated with a delayed transit time.

No MeSH data available.


Related in: MedlinePlus

pERK-ir in nerve fibers but undetectable in ICC of 3-month-old WT, Spry4 KO and KitWT/K641E antrum.Confocal microscopy, sequential channels acquisitions. Left column: grey scale images of PDE3A immunoreactivity (-ir) ICC. Middle column: grey scale images of pERK-ir. Right column: merged images. PDE3A-ir and pERK-ir are displayed in green and in red, respectively, with nuclear counterstain (DAPI) in blue. pERK-ir (red) was consistently detected in myenteric plexus and in nerve fibers in the muscularis propria but not in PDE3A-ir ICC (green). Abbreviations: LM: longitudinal muscle layer, CM: circular muscle layer, scale bar: 20μm
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pone.0124861.g003: pERK-ir in nerve fibers but undetectable in ICC of 3-month-old WT, Spry4 KO and KitWT/K641E antrum.Confocal microscopy, sequential channels acquisitions. Left column: grey scale images of PDE3A immunoreactivity (-ir) ICC. Middle column: grey scale images of pERK-ir. Right column: merged images. PDE3A-ir and pERK-ir are displayed in green and in red, respectively, with nuclear counterstain (DAPI) in blue. pERK-ir (red) was consistently detected in myenteric plexus and in nerve fibers in the muscularis propria but not in PDE3A-ir ICC (green). Abbreviations: LM: longitudinal muscle layer, CM: circular muscle layer, scale bar: 20μm

Mentions: With Sprouty proteins being known as negative regulators of the ERK pathway [14], we hypothesized that phosphorylation of ERK might be elevated in the hyperplastic ICC of the Spry4 KO animals compared to WT mice. We observed pERK-ir in PDE3A-ir ICC of P10 KitK641E/K641E animals, but not in WT nor in Spry4 KO littermates (S6 Fig). In 3-month-old animals, pERK-ir was not detected in PDE3A-ir ICC of Spry4 KO or KitWT/K641E antrum. Conversely, in all genotypes at any age, robust pERK-ir was consistently detected in the myenteric plexus and in intramuscular nerve fibers adjacent to PDE3A-ir ICC in the same field of view (Fig 3) and was thus regarded as an internal positive control.


Hyperplasia of interstitial cells of cajal in sprouty homolog 4 deficient mice.

Thys A, Vandenberghe P, Hague P, Klein OD, Erneux C, Vanderwinden JM - PLoS ONE (2015)

pERK-ir in nerve fibers but undetectable in ICC of 3-month-old WT, Spry4 KO and KitWT/K641E antrum.Confocal microscopy, sequential channels acquisitions. Left column: grey scale images of PDE3A immunoreactivity (-ir) ICC. Middle column: grey scale images of pERK-ir. Right column: merged images. PDE3A-ir and pERK-ir are displayed in green and in red, respectively, with nuclear counterstain (DAPI) in blue. pERK-ir (red) was consistently detected in myenteric plexus and in nerve fibers in the muscularis propria but not in PDE3A-ir ICC (green). Abbreviations: LM: longitudinal muscle layer, CM: circular muscle layer, scale bar: 20μm
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Related In: Results  -  Collection

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pone.0124861.g003: pERK-ir in nerve fibers but undetectable in ICC of 3-month-old WT, Spry4 KO and KitWT/K641E antrum.Confocal microscopy, sequential channels acquisitions. Left column: grey scale images of PDE3A immunoreactivity (-ir) ICC. Middle column: grey scale images of pERK-ir. Right column: merged images. PDE3A-ir and pERK-ir are displayed in green and in red, respectively, with nuclear counterstain (DAPI) in blue. pERK-ir (red) was consistently detected in myenteric plexus and in nerve fibers in the muscularis propria but not in PDE3A-ir ICC (green). Abbreviations: LM: longitudinal muscle layer, CM: circular muscle layer, scale bar: 20μm
Mentions: With Sprouty proteins being known as negative regulators of the ERK pathway [14], we hypothesized that phosphorylation of ERK might be elevated in the hyperplastic ICC of the Spry4 KO animals compared to WT mice. We observed pERK-ir in PDE3A-ir ICC of P10 KitK641E/K641E animals, but not in WT nor in Spry4 KO littermates (S6 Fig). In 3-month-old animals, pERK-ir was not detected in PDE3A-ir ICC of Spry4 KO or KitWT/K641E antrum. Conversely, in all genotypes at any age, robust pERK-ir was consistently detected in the myenteric plexus and in intramuscular nerve fibers adjacent to PDE3A-ir ICC in the same field of view (Fig 3) and was thus regarded as an internal positive control.

Bottom Line: Sprouty homolog 4 was upregulated both at the mRNA and protein level in these cells, suggesting that Sprouty homolog 4 is downstream of oncogenic KIT activation and potentially engaged in the negative feedback loop of ERK activation in this model.Here, we used KitK641E heterozygous and Sprouty homolog 4 knock out animals to quantify interstitial cells of Cajal in situ, using quantitative immunofluorescence for the receptor tyrosine kinase Kit and for phosphodiesterase 3a (PDE3A).We concluded that the lack of Sprouty homolog 4 expression leads to hyperplasia of the interstitial cells of Cajal and is functionally associated with a delayed transit time.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.

ABSTRACT
Gastrointestinal stromal tumors, which are thought to derive from interstitial cells of Cajal or their precursors, often harbor an oncogenic mutation of the KIT receptor tyrosine kinase. Sprouty homolog 4, a known negative regulator of ERK pathway, has been identified in the interstitial cells of Cajal in the KitK641E murine model of gastrointestinal stromal tumors. Sprouty homolog 4 was upregulated both at the mRNA and protein level in these cells, suggesting that Sprouty homolog 4 is downstream of oncogenic KIT activation and potentially engaged in the negative feedback loop of ERK activation in this model. Here, we used KitK641E heterozygous and Sprouty homolog 4 knock out animals to quantify interstitial cells of Cajal in situ, using quantitative immunofluorescence for the receptor tyrosine kinase Kit and for phosphodiesterase 3a (PDE3A). In the antrum of Sprouty homolog 4 knock out mice, hyperplasia of interstitial cells of Cajal was reminiscent of the KitK641E heterozygous mice antrum. Additionally, the density of interstitial cells of Cajal was higher in the colon of adult Sprouty homolog 4 knock out mice than in WT littermates, although hyperplasia seemed more severe in KitK641E heterozygous mice. Functional transit studies also show similarities between Sprouty homolog 4 knock out and KitK641E heterozygous mice, as the total transit time in 9 month old animals was significantly increased in both genotypes compared to WT littermates. We concluded that the lack of Sprouty homolog 4 expression leads to hyperplasia of the interstitial cells of Cajal and is functionally associated with a delayed transit time.

No MeSH data available.


Related in: MedlinePlus