Infiltrating monocyte-derived macrophages polarizes in to anti-inflammatory and neuro-protective phenotype in a rat model of cerebral ischemia

To summarize our results, we found microglia and MDMs are functionally heterogeneous population contributing differently to the disease phenotype. Our data, suggest that during post-ischemic inflammation microglia exhibit pro-inflammatory phenotype, while infiltrating MDMs display anti-inflammatory and neuro-protective phenotype. Apart from up-regulation of some of the classical M2 marker in MDMs, our gene expression profiling using RNA-sequencing revealed a unique signature of MDMs with the up-regulation of genes associated with wound healing, MHCII antigen-presentation and tissue repair. Our results strongly suggest that MDMs infiltrating the CNS parenchyma during the sub-acute of post-ischemic inflammation might contribute to the endogenous mechanism of neuroprotection.