Acta Anatomica Sinica ›› 2019, Vol. 50 ›› Issue (4): 405-410.doi: 10.16098/j.issn.0529-1356.2019.04.001

• Neurobiology •     Next Articles

Expression of repulsive guidance molecule A in polarized microglia after rat focal cerebral ischemia/reperfusion injury

WU Yan-ping QIN Xin-yue* ZHANG Rong-rong HUANG Si-yuan ZHANG Lei   

  1. Department of Neurology,the First Affiliated Hospital of Chongqing Medical University,Chongqing Key Laboratory of Neurology,Chongqing 400016,China
  • Received:2018-09-04 Revised:2018-10-16 Online:2019-08-06 Published:2019-08-06
  • Contact: QIN Xin-yue E-mail:qinxinyue2018@sina.com
  • Supported by:
    General Program of National Natural Science Foundation of China

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 M1 and M2 microglia marker interleukin-1β(IL-1β), 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 Iba1 in microglia. The microglia was incubated with lipopolysaccharides (LPS)or IL-4 in vitro. The mRNA expression of M1 and M2 microglia marker (IL-1β, iNOS, Arg-1, CD206) was tested by Real-time PCR. Western blotting was used to assess the proteins level of RGMa in M1 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 M1 or M2 in vitro. The expression of RGMa protein in M1 and M2 microglia was increased. Conclusion RGMa was strongly expressed in reactive M1 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.

Key words: Repulsive guidance molecule A, Brain ischemia, Reperfusion injury, Microglia polarization, Western blotting, Real-time PCR, Rat