Nyqvist Daniel, Köhler Martin, Wahlstedt Helene, Berggren Per-Olof
The Rolf Luft Center for Diabetes Research L3, Department of Molecular Medicine, Karolinska Institutet, Karolinska University Hospital Solna, S-17176 Stockholm, Sweden.
Diabetes. 2005 Aug;54(8):2287-93. doi: 10.2337/diabetes.54.8.2287.
Pancreatic islet transplantation has emerged as a therapy for type 1 diabetes and is today performed using both freshly isolated and cultured islets. Islet blood vessels are disrupted during islet isolation; therefore, proper revascularization of the transplanted islets is of great importance for islet graft function and survival. We have studied intraislet endothelial cells after islet isolation, during islet culture, and following islet transplantation. By isolating islets from the transgenic Tie2-GFP (green fluorescent protein) mouse, characterized by an endothelial cell-specific expression of GFP, living endothelial cells could be studied in intact islets utilizing two-photon laser-scanning microscopy (TPLSM). Intraislet endothelial cells were found to survive islet transplantation but to rapidly disappear during islet culture. By transplanting freshly isolated Tie2-GFP islets and applying a novel ex vivo model for simultaneous perfusion and TPLSM imaging of the graft-bearing kidneys, GFP fluorescent endothelial cells were found to extensively contribute to vessels within the islet graft vasculature. Real-time imaging of the flow through the islet graft vasculature confirmed that the donor-derived vessels were functionally integrated. Hence, intraislet endothelial cells have the capability of participating in revascularization of pancreatic islets subsequent to transplantation. Therefore, preservation of intraislet endothelial cell mass may improve long-term graft function.
胰岛移植已成为治疗1型糖尿病的一种疗法，如今既使用新鲜分离的胰岛，也使用培养的胰岛进行移植。在胰岛分离过程中，胰岛血管会受到破坏；因此，移植胰岛的适当血管再生对于胰岛移植功能和存活至关重要。我们研究了胰岛分离后、胰岛培养期间以及胰岛移植后的胰岛内内皮细胞。通过从转基因Tie2-GFP（绿色荧光蛋白）小鼠分离胰岛，其特征在于GFP在内皮细胞中的特异性表达，利用双光子激光扫描显微镜（TPLSM）可以在完整的胰岛中研究活的内皮细胞。发现胰岛内内皮细胞在胰岛移植后存活，但在胰岛培养期间迅速消失。通过移植新鲜分离的Tie2-GFP胰岛，并应用一种新的体外模型对移植有胰岛的肾脏进行同步灌注和TPLSM成像，发现GFP荧光内皮细胞对胰岛移植血管系统内的血管有广泛贡献。对胰岛移植血管系统内血流的实时成像证实，供体来源的血管在功能上是整合的。因此，胰岛内内皮细胞有能力参与移植后胰岛的血管再生。因此，保留胰岛内内皮细胞数量可能会改善移植的长期功能。
