Amelioration of intestinal disease severity in cystic fibrosis mice is associated with improved chloride secretory capacity.
The variability in intestinal disease severity in patients with cystic fibrosis (CF) has been associated with the expression of secondary modifier genes. The locus containing these modifier genes in CF patients is syntenic with a modifier locus previously associated with survival in CF transmembrane conductance regulator-knockout mice. These previous studies showed that the proportion of CF mice that survive weaning (mildly affected mice) versus those that succumb to obstruction of the small intestine (severely affected) is related to their genetic background and the expression of modifier genes. In the present work, we show that the basal transepithelial chloride transport measured across jejuna obtained from mice of mixed genetic backgrounds segregates into two groups, some mice having low and others having high, near normal chloride transport. Further, we report that the segregation of mice with respect to intestinal chloride transport correlates with their predicted segregation on the basis of genotype at the "modifier locus." These findings support the hypothesis that intestinal disease modification in CF mice correlates with improved chloride transport through non-CF transmembrane conductance regulator chloride channels.
Gyömörey
K
K
Programme in Cell Biology, Research Institute, Hospital for Sick Toronto, Ontario M5G 1X8, Canada.
Rozmahel
R
R
Bear
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CE
D000818:Animals; D000831:Animals, Newborn; D000833:Animals, Suckling; D018118:Chloride Channels / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D003433:Crosses, Genetic; D003550:Cystic Fibrosis / Q000150:complications* / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D004032:Diet; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007415:Intestinal Obstruction / Q000209:etiology*; D017136:Ion Transport / Q000235:genetics*; D007583:Jejunum / Q000378:metabolism* / Q000473:pathology; D008470:Meconium; D008564:Membrane Potentials; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D012720:Severity of Illness Index
D018118:Chloride Channels; D002712:Chlorides; D019005:Cystic Fibrosis Transmembrane Conductance Regulator