Microglia transcriptome in a rat model of ischemic stroke. Microglia transcriptome in a rat model of ischemic stroke

Microglia are key regulators of inflammatory response after stroke and brain injury. Here we profiled the microglia transcriptome isolated from a spontaneously hypertensive rat model of focal cerebral ischemia. We identified an extensive and persistent upregulation of anti-inflammatory M2-like patterns after stroke and a mild up-regulation of pro-inflammatory M1-like patterns at later stage. We also found that younger brains showed larger microglial response than middle aged brains. Moreover, beyond the standard M1/M2 dichotomy, a wide spectrum of novel microglial polarization states was activated in response to stroke, particularly the phenotypes related to Tlr2 and dietary fatty acids stimulation. Overall design: We analyzed microglial gene expression change from 3 to 14 days after stroke onset and compared the activation pattern between 3-month and 12-month old brains.