Publication by Okreglicka et al.: PPARγ is essential for the development of bone marrow erythroblastic island macrophages and splenic red pulp macrophages.

Tissue-resident macrophages are crucial for first line defense and clearance of apoptotic cells, thereby maintaining tissue homeostasis. In addition, they play distinct roles in every tissue. Bone marrow erythroid island macrophages and spleen red pulp macrophages are responsible for removal of senescent erythrocytes, thereby preventing iron toxicity. We found that the transcription factor PPARg is crucial for neonatal development and proper tissue localization of both macrophage subsets.