在针对严重肢体缺血的内源性组织型纤溶酶原激活物（tPA）缺乏症的小鼠模型中，内皮祖细胞在骨髓中的保留。

Retention of endothelial progenitor cells in bone marrow in a murine model of endogenous tissue plasminogen activator (tPA) deficiency in response to critical limb ischemia.

机构信息

Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.

Division of Thoracic and Cardiovascular Surgery, Department of Surgery, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.

出版信息

Int J Cardiol. 2014 Jan 1;170(3):394-405. doi: 10.1016/j.ijcard.2013.11.021. Epub 2013 Nov 12.

DOI:10.1016/j.ijcard.2013.11.021

PMID:24290069

Abstract

BACKGROUND

This study tested the hypothesis that tissue plasminogen activator (tPA) is crucial for regulating endothelial progenitor cell (EPC) mobilization from bone marrow to circulation in murine critical limb ischemia (CLI) by ligating the left femoral artery.

METHODS

Wild-type (C57BL/6) (n=40) mice were equally divided into group 1A (sham control), group 2A (CLI), group 3A [control-tPA (4.0 mg/kg)] and group 4A [CLI-tPA (intravenously at 3 h after CLI)]. Similarly, tPA knock-out (tPA(-/-)) mice (n=40) were equally divided into group 1B (sham control), group 2B (CLI), group 3B [control-tPA (4.0 mg/kg)], and group 4B (CLI-tPA).

RESULTS

The circulating levels of EPCs (C-kit/CD31+, Sca-1/KDR+, CXCR4/CD34+) were lower in groups 1B and 2B than in groups 1A and 2A, respectively (all p<0.01), and were reversed after tPA treatment (3B vs. 3A or 4B vs. 4A, p>0.05) at 6 h and 18 h post-CLI. Levels of these biomarkers decreased again 14 days after CLI in tPA(-/-) mice compared to those in wild-type between the respective groups (all p<0.01). Laser Doppler flowmetry showed a higher ratio of ischemic-to-normal blood flow in 2A than in 2B and in 4A than in 4B by day 14 after CLI (all p<0.05). Angiogenesis at protein (CXCR4, SDF-1α, VEGF) and cellular (CXCR4+, SDF-1α+, and CD31+ cells) levels was highest in animals with CLI-tPA, significantly higher in mice with CLI only than in sham controls for both wild-type and tPA(-/-) mice (p<0.01).

CONCLUSION

tPA played an essential role in augmenting circulating EPCs, angiogenesis, and blood flow in the ischemic limb in a murine model.

摘要

背景

本研究通过结扎左侧股动脉来检测组织型纤溶酶原激活物（tPA）在调节小鼠严重肢体缺血（CLI）中骨髓内皮祖细胞（EPC）向循环系统动员中的作用。

方法

将 40 只野生型（C57BL/6）（n=40）小鼠平均分为 1A 组（假手术对照）、2A 组（CLI）、3A 组[对照-tPA（4.0mg/kg）]和 4A 组[CLI-tPA（在 CLI 后 3 小时静脉内给药）]。同样，将 40 只 tPA 敲除（tPA(-/-))小鼠平均分为 1B 组（假手术对照）、2B 组（CLI）、3B 组[对照-tPA（4.0mg/kg）]和 4B 组（CLI-tPA）。

结果

与 1A 组和 2A 组相比，1B 组和 2B 组循环中的 EPC 水平（C-kit/CD31+、Sca-1/KDR+、CXCR4/CD34+）均较低（均 p<0.01），并且在 CLI 后 6 小时和 18 小时经 tPA 治疗后恢复正常（3B 组 vs. 3A 组或 4B 组 vs. 4A 组，p>0.05）。与野生型小鼠相比，在 CLI 后 14 天，tPA(-/-)小鼠中这些生物标志物的水平再次降低（p<0.01）。激光多普勒血流仪显示，与 2B 组相比，2A 组在 CLI 后 14 天的缺血与正常血流比值较高，与 4B 组相比，4A 组的比值较高（均 p<0.05）。在 CLI-tPA 治疗的动物中，蛋白质（CXCR4、SDF-1α、VEGF）和细胞（CXCR4+、SDF-1α+、CD31+细胞）水平的血管生成最高，在 CLI 仅存在的小鼠中，与野生型和 tPA(-/-)小鼠的假手术对照相比，均显著高于假手术对照（p<0.01）。