title: Dynamic modulation of Cyp21a1 (21-hydroxylase) expression sites in the mouse developing lung.
abstract: 21-hydroxylase is expressed in the developing lung where it is proposed as a local source of glucocorticoids playing important roles in lung development. We have studied the precise sites of Cyp21a1 expression in the developing mouse lung from the pseudoglandular stage (gestation day (GD) 15.5) to the alveolar stage (postnatal day (PND) 15) by in situ hybridization. Cyp21a1-mRNA was found mainly in epithelial cells from GD 15.5 to PND 5, but the precise site of expression shifted from the distal epithelium during the pseudoglandular and the canalicular stages including the distal epithelium without lumina, to the proximal epithelium and the wall of developing saccules during the perinatal period (GD 19.5 and PND 0), and to the wall of developing saccules and septa, most probably in type I pneumonocytes (PTI), on PND 5. Cyp21a1 expression changed from PTI cells to capillary endothelial cells of the same distal structures during alveolarization. The mesenchyme was generally negative. Endothelial cells forming large vessels were negative. However the tunica adventitia surrounding arteries was Cyp21a1-positive, while several veins were surrounded by a Cyp21a1-positive layer. In conclusion, Cyp21a1 remains expressed in the most distal structure of the developing lung even though these structures are changing, but its expression is not restricted to these areas. Taken together, our data show the highly dynamic modulation of Cyp21a1 expression sites, consistent with the evolving structures of the developing lung.
authors.affiliation: Reproduction, Mother and Youth Health, Centre de recherche du CHU de Québec, Québec, QC, Canada; Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle (CRDSI), Faculté de Médecine, Université Laval, Québec, QC, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Gilbert
authors.affiliation: Reproduction, Mother and Youth Health, Centre de recherche du CHU de Québec, Québec, QC, Canada; Department of Obstetrics/Gynecology & Reproduction, Faculty of Medicine, Université Laval, Québec, QC, Canada; Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle (CRDSI), Faculté de Médecine, Université Laval, Québec, QC, Canada.
authors.forename: Pierre R
authors.initials: PR
authors.lastname: Provost
authors.affiliation: Reproduction, Mother and Youth Health, Centre de recherche du CHU de Québec, Québec, QC, Canada; Department of Obstetrics/Gynecology & Reproduction, Faculty of Medicine, Université Laval, Québec, QC, Canada; Centre de Recherche en Reproduction, Développement et Santé Intergénérationnelle (CRDSI), Faculté de Médecine, Université Laval, Québec, QC, Canada. Electronic address: yves.tremblay@crchudequebec.ulaval.ca.
authors.forename: Yves
authors.initials: Y
authors.lastname: Tremblay
mesh_terms: D056809:Alveolar Epithelial Cells / Q000166:cytology; D000818:Animals; D003900:Desoxycorticosterone / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D005938:Glucocorticoids / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D008168:Lung / Q000196:embryology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011650:Pulmonary Alveoli / Q000196:embryology; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D013255:Steroid 21-Hydroxylase / Q000235:genetics / Q000378:metabolism*
chemical_list: D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D003900:Desoxycorticosterone; C531511:Cyp21a1 protein, mouse; D013255:Steroid 21-Hydroxylase
keywords: Capillary network; Deoxycorticosterone; Development; Glucocorticoid receptor; Pneumonocyte