Neuroinflammation is strongly induced by
cerebral ischemia. The early phase after the onset of
ischemic stroke is characterized by acute neuronal injury, microglial activation, and subsequent infiltration of blood-derived inflammatory cells, including macrophages. Therefore, modulation of the microglial/macrophage responses has increasingly gained interest as a potential therapeutic approach for the
ischemic stroke. In our study, we investigated the effects of peripherally administered
interleukin 13 (IL-13) in a mouse model of permanent
middle cerebral artery occlusion (pMCAo). Systemic administration of
IL-13 immediately after the ischemic insult significantly reduced the lesion volume, alleviated the infiltration of CD45+ leukocytes, and promoted the microglia/macrophage alternative activation within the ischemic region, as determined by
arginase 1 (Arg1) immunoreactivity at 3 days post-
ischemia (dpi). Moreover,
IL-13 enhanced the expression of M2a alternative activation markers Arg1 and Ym1 in the peri-ischemic (PI) area, as well as increased plasma
IL-6 and
IL-10 levels at 3 dpi. Furthermore,
IL-13 treatment ameliorated gait disturbances at day 7 and 14 and sensorimotor deficits at day 14 post-
ischemia, as analyzed by the CatWalk gait analysis system and adhesive removal test, respectively. Finally,
IL-13 treatment decreased neuronal cell death in a coculture model of
neuroinflammation with RAW 264.7 macrophages. Taken together, delivery of
IL-13 enhances microglial/macrophage anti-inflammatory responses in vivo and in vitro, decreases
ischemia-induced brain cell death, and improves sensory and motor functions in the pMCAo mouse model of
cerebral ischemia.