Contreras Juan L, Smyth Cheryl A, Eckstein Christopher, Bilbao Guadalupe, Thompson J Anthony, Young Carlton J, Eckhoff Devin E
Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35295, USA.
Surgery. 2003 Aug;134(2):390-8. doi: 10.1067/msy.2003.250.
Pancreatic islet transplantation has been validated as a treatment for type 1 diabetes. However, a high number of islets is required to establish euglycemia. Transplantation of islets leads to loss of islet vasculature, which requires revascularization to ensure adequate survival. Islet vascular density in transplanted islets is markedly decreased compared with endogenous islets. The feasibility of revascularization of ischemic tissues by mobilizing endothelial progenitor cells or angioblasts has been demonstrated. Therefore, we investigated the therapeutic potential of angioblast mobilization for stimulation of islet revascularization and therefore engraftment after transplantation.
FVB/NJ mice underwent bone marrow transplantation from transgenic mice constitutively expressing beta-galactosidase encoded by LacZ under regulation of the endothelial cell-specific promoter TIE-2 (FEV/NJ-TIE-2-LacZ). Three weeks after reconstitution, animals received an intrahepatic islet syngeneic infusion (FVB/NJ donors). The contribution of angioblasts into sites of islet revascularization was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), beta-galactosidase (beta-gal) activity, and immunohistochemistry. Islet vascular density was assessed morphometrically followed by in situ BS-1 lectin staining and functional islet mass after transplantation by metabolic studies. Angioblasts were mobilized with murine granulocyte-macrophage colony-stimulating factor (GM-CSF) (0.5 microg/day/7 days).
An islet dose-dependent increase in beta-gal was demonstrated after transplantation. These results were confirmed by RT-PCR and immunohistochemistry. GM-CSF increased the number of peripheral angioblasts and their localization into sites of islet revascularization. A significant increase in islet vascular density was observed in animals treated with GM-CSF versus controls. Higher functional islet mass was demonstrated in animals treated with GM-CSF.
Augmentation of angioblasts in the peripheral circulation resulted in higher islet vascular density and engraftment. This novel strategy may improve the results in clinical islet transplantation.
胰岛移植已被确认为1型糖尿病的一种治疗方法。然而，需要大量胰岛才能实现血糖正常。胰岛移植会导致胰岛血管系统丧失，这需要血管再生以确保足够的存活。与内源性胰岛相比，移植胰岛中的胰岛血管密度显著降低。通过动员内皮祖细胞或成血管细胞对缺血组织进行血管再生的可行性已得到证实。因此，我们研究了动员成血管细胞对刺激胰岛血管再生以及移植后植入的治疗潜力。
FVB/NJ小鼠接受来自在内皮细胞特异性启动子TIE-2调控下组成性表达由LacZ编码的β-半乳糖苷酶的转基因小鼠的骨髓移植（FEV/NJ-TIE-2-LacZ）。重建后三周，动物接受肝内同基因胰岛输注（FVB/NJ供体）。通过逆转录聚合酶链反应（RT-PCR）、β-半乳糖苷酶（β-gal）活性和免疫组织化学分析成血管细胞对胰岛血管再生部位的贡献。通过形态计量学评估胰岛血管密度，随后进行原位BS-1凝集素染色，并通过代谢研究评估移植后功能性胰岛质量。用小鼠粒细胞-巨噬细胞集落刺激因子（GM-CSF）（0.5微克/天/7天）动员成血管细胞。
移植后显示β-gal呈胰岛剂量依赖性增加。这些结果通过RT-PCR和免疫组织化学得到证实。GM-CSF增加了外周成血管细胞的数量及其在胰岛血管再生部位的定位。与对照组相比，用GM-CSF治疗的动物中观察到胰岛血管密度显著增加。用GM-CSF治疗的动物显示出更高的功能性胰岛质量。
外周循环中血管母细胞的增加导致更高的胰岛血管密度和植入。这种新策略可能改善临床胰岛移植的结果。
