Expression of repulsive guidance molecule a in polarized microglia after rat focal cerebral ischemia/reperfusion injury / 解剖学报

ABSTRACT

Objective: To investigate the expression of repulsive guidance molecule A (RGMa) in polarized microglia after rat focal cerebral ischemia/reperfusion injury. Methods: Adult male Sprague-Dawley (SD) rats were randomly divided into control group, 7 days cerebral ischemia/reperfusion injury group (I/R), and 14 days I/R group. The transient middle cerebral occlusion (tMCAO) model was induced by ligation with nylon monofilament. Real-time PCR was used to test the mRNA expression of Ml and M2 microglia marker interleukin-1Î2 (IL-1Î2), inducible nitric oxide synthase (iNOS), arginase 1 (Arg-1) and CD206 in ipsilateral cortex at day 7 and day 14. Double immunofluorescence staining was performed to investigate the co-expression of RGMa and Ibal in microglia. The microglia was incubated with lipopolysaccharides (LPS)or IL-4 in vitro. The mRNA expression of Ml and M2 microglia marker (IL-1Î2, iNOS, Arg-1, CD206) was tested by Real-time PCR. Western blotting was used to assess the proteins level of RGMa in Ml and M2 microglia. Results: M1 and M2 microglia marker mRNA level were increased in ipsilateral cortex at day 7 and day 14. RGMa was strongly expressed in reactive microglia at day 7 and day 14. LPS or IL-4 treatment polarized microglia to Ml or M2 in vitro. The expression of RGMa protein in Ml and M2 microglia was increased. Conclusion: RGMa was strongly expressed in reactive Ml and M2 microglia after ischemia/reperfusion injury. RGMa may play an important role in the process of microglia activation and polarization. RGMa may be a novel therapeutic target for stroke.