缓激肽对内皮祖细胞存活、迁移及凋亡的影响

Effects of Bradykinin on the Survival,Migration and Apoptosis of Endothelial Progenitor Cells

目的观察不同浓度的缓激肽对人脐血来源的内皮祖细胞存活、迁移及凋亡的影响。方法采用密度梯度离心法从人脐带血获取单个核细胞,将其接种在人纤维连接蛋白包被的培养板上,培养7天后,收集贴壁细胞。通过免疫荧光法鉴定,FITC标记的异凝集素和DiI标记的乙酰化低密度脂蛋白染色双染色阳性细胞为正在分化的内皮祖细胞,并经流式细胞仪检测技术进一步确定内皮祖细胞。以不同浓度缓激肽(1、10、100 nmol/L)或缓激肽B2受体阻断剂艾替班特+10 nmol/L缓激肽干预内皮祖细胞16 h。分别采用MTT比色法、Transwell小室和膜联蛋白V-异硫氰酸荧光素/碘化丙啶流式细胞术及Hoechst33342染色法观察缓激肽对人内皮祖细胞的存活、迁移以及凋亡影响。结果缓激肽在1、10 nmol/L浓度时可促进人内皮祖细胞存活、迁移,抑制其凋亡(P<0.05)。然而100 nmol/L缓激肽无促人内皮祖细胞存活、迁移和抑制其凋亡的作用(P>0.05)。缓激肽促人内皮祖细胞存活、迁移,抑制其凋亡的作用可被艾替班特阻断(P<0.05)。结论缓激肽在一定范围内可促进内皮祖细胞的存活、迁移,并抑制其凋亡,此作用主要由缓激肽B2受体介导。

Aim To investigate the effects of bradykinin （BK） of different concentrations on the survival, migra tion and apoptosis of human umbilical cord blood derived endothelial progenitor cells （hEPC） in vitro. Methods To tal mononuclear cells （MNC） were isolated from human cord blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin coated culture dished. After 7 days cultured, attached cells were isolated and assessed by immunofluorescence. Differentiating EPC were characterized as adherent cells double positive for both DiI-acLDL and FITC-UEA-1. Flow cytometry were used to further confirm EPC. EPC were treaed with BK of different concentrations （ 1, 10, 100 nmol/L）, or HOE140 （BK B2 receptor inhibitor） plus BK （ 10 nmol/L） for 16 h. The effects of BK on EPC＇ survival, migration and apoptosis were assayed with MTI assay, Transwell chamber assay, flow cytometry assay u sing Annexin V-FITC/PI assay and Hoechst 33342 staining, respectively. Results BK at 1 and 10 nmol/L signif- cantly improved the ability in the survival, migration and anti-apoptosis of hEPC （ P 〈 0. 05）, which was not at the con centration of 100 nmol/L （P 〉 0. 05）. And the effects of BK on these functions of hEPCs could be blocked by HOE140 （P 〈 0. 05）. Conclusion The present study established that BK in a certain concentration range could improve hEPC＇ survival, migration and anti apoptosis capability, and this effect might be mediated by BK-B2 receptor.