LRIG1 Regulates Ontogeny of Smooth Muscle-Derived Subsets of Interstitial Cells of Cajal in Mice.
OBJECTIVE
Interstitial cells of Cajal (ICC) control intestinal smooth muscle contraction to regulate gut motility. ICC within the plane of the myenteric plexus (ICC-MY) arise from KIT-positive progenitor cells during mouse embryogenesis. However, little is known about the ontogeny of ICC associated with the deep muscular plexus (ICC-DMP) in the small intestine and ICC associated with the submucosal plexus (ICC-SMP) in the colon. Leucine-rich repeats and immunoglobulin-like domains protein 1 (LRIG1) marks intestinal epithelial stem cells, but the role of LRIG1 in nonepithelial intestinal cells has not been identified. We sought to determine the ontogeny of ICC-DMP and ICC-SMP, and whether LRIG1 has a role in their development.


METHODS
Lrig1-null mice (homozygous Lrig1-CreERT2) and wild-type mice were analyzed by immunofluorescence and transit assays. Transit was evaluated by passage of orally administered rhodamine B-conjugated dextran. Lrig1-CreERT2 mice or mice with CreERT2 under control of an inducible smooth muscle promoter (Myh11-CreERT2) were crossed with Rosa26-LSL-YFP mice for lineage tracing analysis.


RESULTS
In immunofluorescence assays, ICC-DMP and ICC-SMP were found to express LRIG1. Based on lineage tracing, ICC-DMP and ICC-SMP each arose from LRIG1-positive smooth muscle progenitors. In Lrig1-null mice, there was loss of staining for KIT in DMP and SMP regions, as well as for 2 additional ICC markers (anoctamin-1 and neurokinin 1 receptor). Lrig1-null mice had significant delays in small intestinal transit compared with control mice.


CONCLUSIONS
LRIG1 regulates the postnatal development of ICC-DMP and ICC-SMP from smooth muscle progenitors in mice. Slowed small intestinal transit observed in Lrig1-null mice may be due, at least in part, to loss of the ICC-DMP population.
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
Jumpei
J
Kondo
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
Anne E
AE
Powell
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
Yang
Y
Wang
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
Melissa A
MA
Musser
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
E Michelle
EM
Southard-Smith
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee.
Jeffrey L
JL
Franklin
Departments of Medicine and Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Veterans Affairs Medical Center, Nashville, Tennessee. Electronic address: robert.coffey@vanderbilt.edu.
Robert J
RJ
Coffey
D000818:Animals; D005455:Fluorescent Antibody Technique; D006720:Homozygote; D019426:Integrases; D056885:Interstitial Cells of Cajal / Q000166:cytology / Q000378:metabolism*; D007421:Intestine, Small / Q000166:cytology*; D008562:Membrane Glycoproteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009130:Muscle, Smooth / Q000166:cytology* / Q000254:growth & development; D009197:Myenteric Plexus / Q000166:cytology / Q000254:growth & development*; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D013368:Submucous Plexus / Q000166:cytology / Q000254:growth & development*
C101671:Lrig1 protein, mouse; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; C045073:Cre recombinase; D019426:Integrases
Development; ICC-DMP; ICC-SMP; Intestinal Transit