Abstract:

Objective To observe the effect of tetramethylpyrazine（TMP）on the migration of umbilical cord mesenchymal stem cells（ucMSCs）and investigate the mechanism in vivo and vitro separately. Methods In vivo，ucMSCs were transplanted into MCAO rats by tail vein injection. The migration and localization of GFP⁃ ucMSCs were observed by fluorescence microscope. The expression of related proteins SDF ⁃ 1 and CXCR4 were detected by Western blot. In vitro，the migration of ucMSCs was detected by Transwell method.The effects of TMP treatment and antagonist on the mobility of ucMSCs were observed. The level of interleukin⁃1β（IL⁃1β）was detected by ELISA and the expression of migration related proteins was detected. Results In vivo，it was found that the number of ucMSCs migrated and located in the cerebral infarction area after TMP pretreatment（IOD 2.9 × 105） increased significantly compared to untreated group（IOD 0.4 × 105）（P < 0.05）. The expression of SDF⁃1 and CXCR4 also increased significantly，which was inhibited by adding antagonists（P < 0.05）；In vitro，the number of migrating cells increased from 20 to 88 per region by TMP pretreatment（P < 0.05），which was consistent with the increased expression of CXCR4. The expression of inflammatory factor IL⁃1 β in PC12 cells was reduced by TMP treatment（from 17.2 to 13.5 pg/mL）. Conclusion Tetramethylpyrazine improves the migration rate of umbilical cord mesenchymal stem cells by regulating SDF ⁃ 1/CXCR4 axis.The transplantation microenvironment was also improved by inhibiting inflammation. This study provides experimental basis for the combination of traditional Chinese medicine and stem cells in the treatment of ischemic stroke.

Key words: tetramethylpyrazine,  , umbilical cord mesenchymal stem cells,  , cerebral ischemia?reperfu? sion,  , transplantation,  , migration