Congenital tracheal malformation in cystic fibrosis transmembrane conductance regulator-deficient mice.
In cystic fibrosis (CF) patients, the major alteration in pulmonary function is due to peripheral airway obstruction. In the present study, we investigated the possibility that alterations in the extrathoracic airways, particularly in the trachea that expresses high levels of CFTR (CF transmembrane conductance regulator), may contribute to respiratory dysfunction. We performed morphological analyses of the trachea and airway functional studies in adult Cftr knockout (Cftr(-/-)) and F508del-CFTR mice and their controls. Macroscopic and histological examination of the trachea showed the presence of one to seven disrupted or incomplete cartilage rings in Cftr(-/-) mice (23/25) while only a few Cftr(+/+) mice (6/25) had one abnormal ring. Tracheal defects were mainly localized in the proximal trachea. In 14 Cftr(-/-) mice, frontal disruption of the first three to six rings below the cricoid cartilage were associated with upper tracheal constriction. Similar tracheal abnormalities were detected in adult F508del-CFTR and in newborn Cftr(-/-) and F508del-CFTR mice. Tracheal and ventilatory function analyses showed in Cftr(-/-) mice a decreased contractile response of the proximal trachea and a reduced breathing rate due to an increase in the inspiratory and expiratory times. In F508del-CFTR mice, the expiratory time was longer than in controls. Therefore, these structural and functional abnormalities detected in adult and newborn CF mouse models may represent congenital malformations related to CFTR dysfunction. These results raise important questions concerning the mechanisms governing tracheal development within the context of CFTR protein dysfunction and the implication of such abnormalities in the pathogenesis of airway disease in CF.
Bonvin
Elise
E
UPMC Université Paris 06, F-75005 Paris, France.
Le Rouzic
Philippe
P
Bernaudin
Jean-François
JF
Cottart
Charles-Henry
CH
Vandebrouck
Clarisse
C
Crié
Antoine
A
Leal
Teresinha
T
Clement
Annick
A
Bonora
Monique
M
D000818:Animals; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009119:Muscle Contraction / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology; D012119:Respiration; D014132:Trachea / Q000166:cytology / Q000473:pathology; D014133:Tracheal Diseases / Q000151:congenital* / Q000235:genetics / Q000473:pathology
D019005:Cystic Fibrosis Transmembrane Conductance Regulator