Effect of efferocytosis on the inflammatory response of primary murine macrophages
Despite the importance of rapid adaptive responses for an efficient resolution of inflammation, which are commonly regulated on a post-transcriptional and specifically translational level, translational changes caused by efferocytosis remain largely elusive. To gain further insights into such gene regulatory principles, we analyzed translational changes in efferocytic and non-efferocytic bone marrow-derived macrophages (BMDM) in the course of inflammation. Using total RNA-sequencing, we confirmed that efferocytosis induced a pro-resolution signature in LPS-stimulated, inflammatory macropahges. Interestingly though, while LPS-induced transcriptional changes appeared rather small between efferocytic and non-efferocytic macrophages, we observed considerable differences on the level of de novo synthesized proteins. We further identified translationally regulated targets showing reduced translation upon inflammatory stimulation, which was buffered upon efferocytosis. Herein, pro-resolving matrix metallopeptidase 12 (Mmp12) emerged as a novel translationally regulated candidate, which was translationally repressed during early inflammation and increased during the resolution phase. Functionally, the translational repression of Mmp12 was linked to increased spontaneous two-dimensional migration. In summary, we identified the novel translationally regulated target Mmp12 in the context of the resolution of inflammation in primary murine macrophages, which is associated with a modulation of spontaneous migration. Overall design: total RNA-seq of naive and efferocytic primary mouse macrophages stimulated with LPS/IFNg for 6h (n=2)