Interleukin-4 Is Essential for Microglia/Macrophage M2 Polarization and Long-Term Recovery After Cerebral Ischemia

• DOI: 10.1161/strokeaha.115.012079
• Publication Date: 2016-01-25T21:36:01Z
• Authors: Xiangrong Liu; Jia Liu; Shangfeng Zhao; Haiyue Zhang; Wei Cai; Mengfei Cai; Xunming Ji; Rehana K. Leak; Yanqin Gao; Jun Chen; Xiaoming Hu
• Keywords: Stroke

Background and Purpose— Interleukin-4 (IL-4) is a unique cytokine that may contribute to brain repair by regulating microglia/macrophage functions. Thus, we examined the effect of IL-4 on long-term recovery polarization in 2 well-established stroke models. Methods— Transient middle cerebral artery occlusion or permanent distal was induced wild-type knockout C57/BL6 mice. In separate cohort animals, (60 ng/d for 7 days) vehicle infused into cerebroventricle after transient occlusion. Behavioral outcomes were assessed Rotarod, corner, foot fault, Morris water maze tests. Neuronal tissue loss verified independent neuron markers. Markers classically activated (M1) alternatively (M2) microglia real-time polymerase chain reaction, immunofluorescence, flow cytometry. Results— Loss exacerbated sensorimotor deficits impaired cognitive functions ≤21 days post injury. contrast delayed deterioration neurological functions, deficiency increased neuronal only acute phase (5 had no impact 14 21 promoted expression M1 markers M2 at 5 Administration ischemic also enhanced functional recovery. Conclusions— The improves stroke, perhaps through phenotype induction microglia/macrophages. These results are first suggest immunomodulation with promising approach promote stroke.