Pulmonary epithelial cell differentiation in the nitrofen-induced congenital diaphragmatic hernia.
OBJECTIVE
In congenital diaphragmatic hernia (CDH), there is pulmonary neuroendocrine cell (PNEC) hyperplasia and Clara (nonendocrine) cell hypoplasia, the meaning of which remains unknown. In embryonic/fetal lung, an intricate cross talk between Notch pathway and basic helix-loop-helix transcription factors Mash1 and Hes1 determines the balance between endocrine and nonendocrine epithelial cell fate. Differences at the molecular level in pulmonary epithelial cell differentiation between control and CDH hypoplastic lungs were investigated.


METHODS
The nitrofen-induced CDH rat model was used. At 15.5 days postconception (dpc), fetuses were assigned to 2 experimental groups: control and nitrofen (exposed to nitrofen, without CDH), whereas at 17.5, 19.5, and 21.5 dpc, fetuses were assigned to 3 experimental groups: control, nitrofen, and CDH (exposed to nitrofen, with CDH). The fetal lungs were processed for expression quantification of CC10, Hes1, Mash1, and Dll1 by real-time polymerase chain reaction.


RESULTS
In control fetuses, expression of all studied genes increased with gestational age. In nitrofen-exposed fetal lungs, endocrine cell marker Mash1 was downregulated only at the earliest studied gestational age, whereas Dll1 expression levels were significantly increased in the CDH group at 19.5 and 21.5 dpc. Regarding nonendocrine markers, Hes1 presented increased expression at 15.5 and 19.5 dpc, whereas CC10 was downregulated at 17.5 and 19.5 dpc but not at term.


CONCLUSIONS
This study suggests that PNEC hyperplasia in CDH fetal lung is likely because of Notch signaling deregulation, whereas Clara cell hypoplasia in CDH lungs could be a consequence of protein synthesis delay, reflecting a functional maturation hindrance and not a cell fate commitment problem.
Santos
Marta
M
Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4709-057 Braga, Portugal.
Nogueira-Silva
Cristina
C
Baptista
Maria J
MJ
Soares-Fernandes
João
J
Moura
Rute S
RS
Correia-Pinto
Jorge
J
D000704:Analysis of Variance; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D002454:Cell Differentiation; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D005315:Fetal Diseases / Q000139:chemically induced / Q000473:pathology*; D006548:Hernia, Diaphragmatic / Q000139:chemically induced / Q000150:complications*; D065630:Hernias, Diaphragmatic, Congenital; D018398:Homeodomain Proteins / Q000378:metabolism; D008168:Lung / Q000002:abnormalities / Q000187:drug effects / Q000473:pathology; D008171:Lung Diseases / Q000139:chemically induced / Q000151:congenital / Q000473:pathology*; D010647:Phenyl Ethers; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072056:Transcription Factor HES-1; D014598:Uteroglobin / Q000378:metabolism
D051792:Basic Helix-Loop-Helix Proteins; D018398:Homeodomain Proteins; D010647:Phenyl Ethers; D012333:RNA, Messenger; D000072056:Transcription Factor HES-1; D014598:Uteroglobin; C499318:Ascl1 protein, rat; C489735:Hes1 protein, rat; C556391:Scgb1a1 protein, rat; C007350:nitrofen