Objective:Vascular cell adhesion molecule 1(VCAM1)is involved in a series of physiological and pathological processes,such as immune and inflammatory response,tumor cell metastasis and invasion.But under trau-matic brain injury(TBI),specific types of cells with VC AM1 expression and the related functions are not clear.In order to further explore the specific functions of VCAM1 involved in TBI,this study constructed reporter mice of VCAM1 to explore the response of VCAM1 to TBI in detail.Methods:VCAM1-Cre/ERT2::Ai14 reporter mice were constructed by gene targeting technology and Cre/loxP system,the labeled cell types and labeling efficiency were validated by im-munofluorescence staining and reporter mice hybridization.The stab wound model was used to simulate TBI to induce the changes of VCAM1 expression in cells,and the characteristics of VCAM1 positive astrocytes were detected by immu-nofluorescence staining and fluorescent probe labeling.Results:The labeling efficiency of VCAM1-Cre/ERT2::Ai14 re-porter mice was higher than that of VCAM1 antibody as was seen by labeling of more endothelial cells of blood vessels and unique astrocytes.The distribution of these astrocytes was specific,for example in the nucleus accumbens,amygda-la,hypothalamus,and paraventricular fiber systems.TBI could significantly induce the expression of VCAM1 in astro-cytes(P＜0.0001).These induced astrocytes developed reactive qualities,including somal hypertrophy,GFAP ex-pression and proliferative ability.Conclusion:VCAM1-Cre/ERT2::Ai14 reporter mice could label cells with VCAM1 expression more sensitively,so they were more effective tools for observing expression and function of VCAM1.The up-regulation of VCAM1 expression in astrocytes after TBI surgery suggested that VCAM1 was an inflammatory response molecule in astrocytes,we recommended it as a new molecular indicator of reactive astrocytes.

Objective:Vascular cell adhesion molecule 1(VCAM1)is involved in a series of physiological and pathological processes,such as immune and inflammatory response,tumor cell metastasis and invasion.But under trau-matic brain injury(TBI),specific types of cells with VC AM1 expression and the related functions are not clear.In order to further explore the specific functions of VCAM1 involved in TBI,this study constructed reporter mice of VCAM1 to explore the response of VCAM1 to TBI in detail.Methods:VCAM1-Cre/ERT2::Ai14 reporter mice were constructed by gene targeting technology and Cre/loxP system,the labeled cell types and labeling efficiency were validated by im-munofluorescence staining and reporter mice hybridization.The stab wound model was used to simulate TBI to induce the changes of VCAM1 expression in cells,and the characteristics of VCAM1 positive astrocytes were detected by immu-nofluorescence staining and fluorescent probe labeling.Results:The labeling efficiency of VCAM1-Cre/ERT2::Ai14 re-porter mice was higher than that of VCAM1 antibody as was seen by labeling of more endothelial cells of blood vessels and unique astrocytes.The distribution of these astrocytes was specific,for example in the nucleus accumbens,amygda-la,hypothalamus,and paraventricular fiber systems.TBI could significantly induce the expression of VCAM1 in astro-cytes(P＜0.0001).These induced astrocytes developed reactive qualities,including somal hypertrophy,GFAP ex-pression and proliferative ability.Conclusion:VCAM1-Cre/ERT2::Ai14 reporter mice could label cells with VCAM1 expression more sensitively,so they were more effective tools for observing expression and function of VCAM1.The up-regulation of VCAM1 expression in astrocytes after TBI surgery suggested that VCAM1 was an inflammatory response molecule in astrocytes,we recommended it as a new molecular indicator of reactive astrocytes.