Transcription profiling of fetal lung from wild type and CREB knock-out mice

ABSTRACT: The cAMP response element binding protein (Creb) is a member of a leucine zipper transcription factor family that regulates gene expression primarily in response to the intracellular cAMP signalling pathway. Previous studies have shown Creb1-null mice suffer respiratory failure with lung atelectasis and a large reduction in Sftpd mRNA. Using a new line of Creb1-null mice we have further investigated Creb function in the developing mouse lung, focussing on differentiation of the airway epithelium. The lungs of Creb1-null fetal mice showed normal respiratory development until E17.5 when proximal and distal airways fail to inflate. Subsequent ultrastructural analysis of the lungs of E17.5 Creb1-null fetal mice revealed a defect in AEC differentiation with a reduction in proportions of type-II AECs and in particular, a very large reduction in type-I AECs. Furthermore, immunostaining for the proximal epithelial cell markers Scgb1a1 (also known as CC10) (Clara cells), Foxj1 (Ciliated cells), and CGRP (Neuroendocrine cells) showed delayed or defective proximal epithelial differentiation in Creb1-null fetal lungs. Quantitative real time PCR (qRT-PCR) analysis at E17.5 in Creb1-null fetal lungs showed differential expression of mRNAs for Creb/Atf1 subfamily members, surfactant-associated proteins, type-I AEC markers and proximal epithelial markers. Furthermore, whole-genome microarray analysis at E17.5 in Creb1-null fetal lungs has provided novel genes which will prove useful to further investigate Creb-mediated signalling in lung development. Together these results demonstrate that Creb plays a key role in determining cell lineages and differentiation of the developing lung epithelium.

ORGANISM(S): Mus musculus

SUBMITTER: Kheng Tan 

PROVIDER: E-MEXP-1295 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress