Expression and role of chemokine CCL21 and its receptor CCR7 in ischemic brain white matter lesion / 国际脑血管病杂志

ABSTRACT

Objective:To investigate the expression and role of chemokine CCL21 and its receptor CCR7 in ischemic brain white matter lesion (WML).Methods:Permanent bilateral common carotid artery occlusion (BCCAo) was used to prepare an ischemic WML model in C57Bl/6 mice. Evans blue perfusion staining was used to assess the permeability of the blood-brain barrier. Immunofluorescence staining was used to detect the expression of CCL21 and its receptor CCR7 in ischemic WML tissues. Cerebral microvascular endothelial cells were subjected to oxygen glucose deprivation (OGD) to prepare ischemic WML model in vitro. The expression level of CCL21 protein after OGD 6 hours and reoxygenation 24 hours was detected by Western blot analysis. Primary cultured oligodendrocyte precursor cells (OPCs) were treated with recombinant CCL21, and then inflammatory reaction was induced by lipopolysaccharide. The mRNA expression level of myelin basic protein (MBP), a marker of mature oligodendrocytes, was detected by quantitative polymerase chain reaction. Results:Compared with the sham operation group, the exudation of Evans blue stain in the brain tissue was significantly increased after BCCAo ( P<0.05), the expression level of CCL21 in cerebral vascular endothelial cells and CCR7 in OPCs was significantly down-regulated ( P<0.05). After cerebral microvascular endothelial cells were subjected to OGD, the expression level of CCL21 protein were significantly down-regulated compared with the control group ( P<0.05). After OPCs were treated with recombinant CCL21, the expression level of MBP mRNA was significantly up-regulated ( P<0.05). Conclusions:The expression of CCL21/CCR7 was significantly down-regulated after WML. The application of recombinant CCL21 may promote the differentiation and maturation of OPCs cells, suggesting that it may play an important role in ischemic WML.