1型糖尿病小鼠下肢缺血恢复受损的机制

目的研究1型糖尿病小鼠肢体对缺血刺激的血管生成反应,及其骨髓内皮祖细胞的数量和功能。方法雄性C57BL/6小鼠20只,静脉注射四氧嘧啶,建立1型糖尿病模型;年龄、性别相匹配的正常小鼠20只为对照组。所有小鼠均行单侧股动脉结扎切除术,建立下肢动脉缺血模型。应用激光多普勒扫描仪记录肢体血流恢复情况至术后第4周。取缺血下肢肌肉组织行免疫组织化学染色,评价血管密度。分离小鼠股骨和胫骨骨髓间充质干细胞,采用流式细胞术鉴定内皮祖细胞,收集后进行培养,观察其增殖和分化能力。结果小鼠静脉注射四氧嘧啶后,出现典型1型糖尿病表现。1型糖尿病小鼠下肢缺血后血流恢复、缺血肢体肌肉血管密度及1型糖尿病小鼠骨髓内皮祖细胞的数量、增殖和分化能力均显著低于对照组(P<0.001,P<0.05)。结论1型糖尿病小鼠肢体对缺血刺激的反应明显减弱,可能与糖尿病状态下内皮祖细胞的数量和功能降低有关。

Mechanisms of impaired perfusion recovery in type 1 diabetic mouse

Objective To investigate the perfusion restoration of type 1 diabetic mouse under the setting of surgically induced hind limb ischemia and the number and function of bone marrow endothelial progenitor cells(EPCs).Methods Forty mice were randomly divided into two groups:one group was injected with alloxan through tail vein to induce type 1 diabetes mellitus,and another group was set as control group.All mice were surgically induced to hind limb ischemia.Blood flow was monitored with Laser Doppler perfusion imaging for 4 weeks after artery ligation.Uen mice in each group were sacrificed and muscle tissues were harvested for histological detection.The remaining mice were sacrificed 7 days after surgery,bone marrow mesenchymal stem cells were harvested and EPCs were analyzed by flow cytometry and then were collected to culture for functional detection.Results All mice received alloxan injection showed typical symptoms of type 1 diabetes mellitus.Restoration of blood flow was significantly slower in type 1 diabetic mice with lower level of vascular density in ischemic muscles than control group(P<0.001,P<0.05).The number and function of EPCs(CD34 and vascular endothelial growth factor receptor 2 double positive cells) in type 1 diabetic mice were significantly lower than that in control mice(P<0.05).Conclusions The spontaneous angiogenesis is attenuated with a decreased number and function of EPCs in the setting of type 1 diabetes mellitus.This may partly explain why diabetic patients with peripheral artery diseases have more aggressive disease and poorer outcome.