Hyperplasia of interstitial cells of cajal in sprouty homolog 4 deficient mice.
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.
Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
An
A
Thys
Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
Pierre
P
Vandenberghe
Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
Perrine
P
Hague
Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California, San Francisco, California, United States of America; Department of Pediatrics and Institute for Human genetics, University of California, San Francisco, California, United States of America.
Ophir D
OD
Klein
IRIBHM, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
Christophe
C
Erneux
Laboratory of Neurophysiology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium.
Jean-Marie
JM
Vanderwinden
D000818:Animals; D003106:Colon / Q000378:metabolism / Q000473:pathology; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3 / Q000378:metabolism; D004195:Disease Models, Animal; D004392:Dwarfism / Q000378:metabolism / Q000473:pathology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005838:Genotype; D006965:Hyperplasia; D056885:Interstitial Cells of Cajal / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D018345:Mice, Knockout; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D011706:Pyloric Antrum / Q000378:metabolism / Q000473:pathology; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D013576:Syndactyly / Q000378:metabolism / Q000473:pathology
D009419:Nerve Tissue Proteins; C499037:Spry4 protein, mouse; D019009:Proto-Oncogene Proteins c-kit; D048049:Extracellular Signal-Regulated MAP Kinases; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; C517289:Pde3a protein, mouse