title: The miR-200 family and its targets regulate type II cell differentiation in human fetal lung.
abstract: Type II cell differentiation and expression of the major surfactant protein, SP-A, in mid-gestation human fetal lung (HFL) are induced by cAMP and inhibited by TGF-β. cAMP induction of SP-A promoter activity is mediated by increased phosphorylation and DNA binding of thyroid transcription factor-1 (TTF-1/Nkx2.1), a master regulator of lung development. To further define mechanisms for developmental induction of surfactant synthesis in HFL, herein, we investigated the potential roles of microRNAs (miRNAs, miRs). To identify and characterize differentially regulated miRNAs in mid-gestation HFL explants during type II pneumocyte differentiation in culture, we performed miRNA microarray of RNA from epithelial cells isolated from mid-gestation HFL explants before and after culture with or without Bt2cAMP. Interestingly, the miR-200 family was significantly up-regulated during type II cell differentiation; miR-200 induction was inversely correlated with expression of known targets, transcription factors ZEB1/2 and TGF-β2. miR-200 antagonists inhibited TTF-1 and surfactant proteins and up-regulated TGF-β2 and ZEB1 expression in type II cells. Overexpression of ZEB1 in type II cells decreased DNA binding of endogenous TTF-1, blocked cAMP stimulation of surfactant proteins, and inhibited miR-200 expression, whereas cAMP markedly inhibited ZEB1/2 and TGF-β. Importantly, overexpression of ZEB1 or miR-200 antagonists in HFL type II cells also inhibited LPCAT1 and ABCA3, enzymes involved in surfactant phospholipid synthesis and trafficking, and blocked lamellar body biogenesis. Our findings suggest that the miR-200 family and ZEB1, which exist in a double-negative feedback loop regulated by TGF-β, serve important roles in the developmental regulation of type II cell differentiation and function in HFL.
authors.affiliation: From the Departments of Biochemistry and Obstetrics and Gynecology, North Texas March of Dimes Birth Defects Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038.
authors.forename: Houda
authors.initials: H
authors.lastname: Benlhabib
authors.affiliation: From the Departments of Biochemistry and Obstetrics and Gynecology, North Texas March of Dimes Birth Defects Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: From the Departments of Biochemistry and Obstetrics and Gynecology, North Texas March of Dimes Birth Defects Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038.
authors.forename: Brianne M
authors.initials: BM
authors.lastname: Pierce
authors.affiliation: From the Departments of Biochemistry and Obstetrics and Gynecology, North Texas March of Dimes Birth Defects Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9038 carole.mendelson@utsouthwestern.edu.
authors.forename: Carole R
authors.initials: CR
authors.lastname: Mendelson
mesh_terms: D008243:1-Acylglycerophosphocholine O-Acyltransferase / Q000378:metabolism; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D056809:Alveolar Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005333:Fetus / Q000166:cytology / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005865:Gestational Age; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis*; D012097:Repressor Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000378:metabolism; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: C441524:ABCA3 protein, human; D018528:ATP-Binding Cassette Transporters; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D035683:MicroRNAs; D012097:Repressor Proteins; C504003:TTF1 protein, human; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; C486307:ZEB1 protein, human; C492363:ZEB2 protein, human; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1; D008243:1-Acylglycerophosphocholine O-Acyltransferase; C526202:Lpcat1 protein, human
keywords: cyclic AMP (cAMP); development; lung; microRNA (miRNA); pulmonary surfactant; transcription factor; transforming growth factor beta (TGF-beta)