活性氧促进中性粒细胞与骨髓基质细胞黏附及机制初探

目的:探讨活性氧对中性粒细胞与骨髓基质细胞(BMSCs)黏附的影响及其机制。方法:采用密度梯度离心法从小鼠胫骨和股骨分离骨髓中性粒细胞,并用DMSO诱导HL60细胞分化为成熟中性粒细胞(d HL60细胞)。利用分光光度法检测CFDA-SE标记的小鼠骨髓中性粒细胞和d HL60细胞在H_2O_2刺激下与BMSCs的黏附。利用荧光显微成像技术和Western blot检测携带去谷胱甘肽化酶谷氧还蛋白1(Grx1)表达载体的慢病毒感染的d HL60细胞中Grx1的表达。PCR检测Grx1敲除小鼠的基因型。结果:(1) Diff-Quick染色显示,分离的骨髓中性粒细胞纯度高于90%; H_2O_2处理后,中性粒细胞与BMSCs黏附率显著增加(P 0. 01)。(2)荧光显微镜观察和Western blot结果表明,Grx1稳转株d HL60细胞中Grx1的表达水平较空载体稳转株细胞显著增加;体外黏附实验表明过表达Grx1的d HL60细胞较对照组d HL60细胞,在相同H_2O_2浓度下,黏附到BMSCs程度显著下降(P 0. 01)。(3)经PCR鉴定,实验所用基因敲除小鼠在全基因水平上未见Grx1;且敲除Grx1的小鼠较野生型小鼠,在相同浓度H_2O_2刺激下,其骨髓中性粒细胞与BMSCs黏附率显著升高。(4)血管细胞黏附分子1(VCAM-1)抗体预处理BMSCs后,由H_2O_2引起的d HL60与BMSCs之间的黏附增强回复到了静息水平。结论:活性氧促进骨髓中中性粒细胞与BMSCs的黏附,其可能的机制是通过诱导VCAM-1黏附信号的S-谷胱甘肽化。

ROS promotes adhesion of neutrophils to bone marrow stromal cells and its mechanism

AIM:To investigate the effect of reactive oxygen species (ROS) on the adhesion of neutrophils to bone marrow stromal cells (BMSCs) and its mechanism. METHODS:Murine bone marrow neutrophils were isolated from mouse tibia and femur by density gradient centrifugation. HL60 cells were induced into human mature neutrophils (dHL60 cells) by DMSO treatment. Murine bone marrow neutrophils and dHL60 cells were labeled with CFDA-SE. The adhesion of the CFDA-SE-labeled cells to BMSC monolayer was tested by microplate reader after H₂O₂ treatment. The level of glutaredoxin 1 (Grx1) in dHL60 cells infected by lentivirus carrying Grx1 expression vector was examined by fluorescence microscopy and Western blot. The genotype of Grx1^-/- mice was identified by PCR. RESULTS:Diff-Quick staining result displayed that the purity of murine bone marrow neutrophil was higher than 90%. The adhesion of H₂O₂-pretreated neutrophils to BMSCs was higher than that of the control cells (P<0.01). The expression of Grx1 in Grx1 stably transfected dHL60 cells was significantly higher than that in the control cells. After H₂O₂ treatment, the results of in vitro adhesion assay showed that the adhesion of dHL60 cells with Grx1 over-expression to BMSCs was lower than that of the control cells (P<0.01). The results of PCR showed no Grx1 was detected at the whole gene level in Grx1^-/- mice. Compared with the neutrophils from wild-type mice, the neutrophils from Grx1^-/- mice displayed increased adhesion to BMSCs after H₂O₂ treatment. Vascular cell adhesion molecule-1 (VCAM-1) antibody pretreatment induced the adhesion rate back to non-H₂O₂-treated condition. CONCLUSION:ROS promotes the adhesion of neutrophils to BMSCs in bone marrow, which might be regulated by VCAM-1 adhesion signaling-related S-glutathionylation.