Effects of M1 microglia-derived exosomes on the function of the blood-brain barrier
Objective:To investigate the effects of M1 microglia-derived exosomes(M1-exo)on the function of an in-vitro blood-brain barrier(BBB)model and the expression of tight junction proteins between vascular endothelial cells.Methods:Mouse microglia-derived BV2 cells were stimulated with lipopolysaccharide to be polarized towards the M1 phenotype,and exosomes were isolated and extracted after the phenotype was confirmed by flow cytometry.An in-vitro BBB model was constructed using the mouse brain micro-vascular endothelial cell line b.End3 and primary cultured mouse astrocytes.The BBB model was co-cultured with exosomes of differ-ent sources in three groups:normal culture for b.End3 cells(b.End3 group);b.End3 cells+25 μg/mL exosomes derived from normal BV-2 cells(b.End3+BV2-exo group);and b.End3 cells+25 μg/mL M1-exo(b.End3+M1-exo group).Trans-endothelial electrical resistance(TEER)and Lucifer yellow permeability were examined.The expression of tight junction complex proteins(claudin-1,occlu-din,zonula occludens-1[ZO-1],and junctional adhesion molecules)was measured by Western blot.Results:Microglia were success-fully polarized to the M1 type,and the positivity rate of the M1 marker CD16/32 was significantly increased compared with the control group(P=0.023).After co-culture with M1-exo,the TEER of the in-vitro BBB model was significantly decreased(P＜0.001),and Lucifer yellow permeability was significantly increased(P＜0.001).Compared with the b.End3 group and b.End3+BV2-exo group,the b.End3+M1-exo group showed significantly decreased expression levels of claudin-1,occludin,and ZO-1.Conclusion:M1-exo can disrupt the integrity of BBB and interfere with its normal function.
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维普
