The miR-200 Family and their Targets in Regulation of Type II Cell Differentiation in Human Fetal Lung

ABSTRACT: Type II cell differentiation and expression of the major surfactant protein, SP-A, in midgestation human fetal lung (HFL) are markedly induced by cAMP and inhibited by TGF-β. cAMP induction of SP-A promoter activity is mediated by increased phosphorylation and in vivo binding of TTF-1/Nkx2.1, a critical transcription factor in lung development. To further define mechanisms for developmental induction of surfactant synthesis in HFL, herein, we investigated the potential role 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 analysis of RNA isolated from epithelial cells from midgestation HFL explants before and after culture ± Bt2cAMP. Interestingly, the miR-200 family was significantly upregulated during type II cell differentiation; miR-200 family induction was inversely correlated with expression of its known targets, transcription factors ZEB1 and ZEB2, and TGF-b2. miR-200 antagonists inhibited TTF-1 and SP-A expression and upregulated TGF-β2 and ZEB1 expression in type II cells. Overexpression of ZEB1 in cultured type II cells decreased DNA binding of endogenous TTF-1, blocked cAMP stimulation of SP-A 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 markedly suppressed accumulation of lamellar bodies, organelles that store surfactant. Our findings suggest that the miR-200 family and ZEB1, which exist in a double-negative feedback loop regulated by TGF-β, serve important regulatory roles in the developmental regulation of type II cell differentiation and SP-A expression in HFL.

ORGANISM(S): Homo sapiens

PROVIDER: GSE61183 | GEO | 2015/10/01

SECONDARY ACCESSION(S): PRJNA260426

REPOSITORIES: GEO