PPARγ controls alveolar macrophage identity [part1]

Tissue-resident macrophages comprise heterogeneous populations with unique functions and distinct gene expression signatures. While it has been established that they mostly originate from embryonic progenitors, the signals inducing a characteristic tissue-specific differentiation program remain unknown. Here we identify PPARγ as the crucial transcription factor determining perinatal alveolar macrophage (AM) development and identity. Development of the fetal monocyte derived AM precursor was largely abrogated in CD11c-Cre/Ppargfl/fl mice. To reveal the underlying changes in gene expression, we performed microarray analysis of sorted WT and KO AM and pre-AM from 3 different timepoints. Part1: d2 and d11 sorts & array pre-AM FACS-sorted from lungs of d2 and mature AM from d11 PPARgfl/fl (WT) and CD11c-cre/PPARgfl/fl (KO) mice and subsequently processed for RNA extraction and hybridization on Affymetrix microarrays. 2 biological replicates per group, each composed of pooled cells from 2 individual mice