Transcriptome profiles of pancreatic macrophage following AP injury

Upon injury, immune cells undergo dynamic changes in population size, differentiation state and function in response to maintain organismal integrity. Myeloid cells, mostly macrophages have been shown to act as positive regulators of development, tissue homoeostasis, inflammation，especially in inducing resolution after inflammation, remodeling and repair. Here we report what specific role macrophages play in every precisely dynamical period after injury in vivo. We first confirmed that M2-like macrophages from recruited monocytes accumulate during AP recovery(RAP). By macrophage depletion in different time points, before or after ADM phase, we elucidate distinct roles of macrophage in different stages of AP recovery. To further understanding the phenotype and function of macrophage during AP recovery, pancreatic macrophages were isolated in all precisely indicated time points for RNA-seq analysis. By analyzing RNA-seq result, we verify PI3K-AKT activation in macrophage aids in resolving inflammation in ADM phase and IL4RA deficiency impairs M2-like macrophages and AP recovery. Finally, we further investigated PGE2’s role in regulating M2 macrophage polarization and we found PGE2 augments IL4Ra signaling to enhance M2 activation of macrophage. Briefly, acute pancreatitis (AP) was induced using caerulein. Mice were fasted one night before injection, after that mice were given 10 hourly i.p. injections of saline as control or 100 mg/kg caerulein, and harvested immediately on d1, d3, d5, d7 post the first injection.We named mock as d0. Pancreas leukocytes were enriched by CD45.2 magnetic beads and sorted by FACSAriaⅡto get pure macrophages (CD45+CD11b+F4/80+). RNA was isolated to conduct RNA-seq. Each sample has 1 repeat, but was pooled from more than 3 mice.