Department of Gastrointestinal, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan Province, China.
Organ Transplantation Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, Sichuan Province, China.
PLoS One. 2020 Dec 3;15(12):e0234670. doi: 10.1371/journal.pone.0234670. eCollection 2020.
Although sites for clinical or experimental islet transplantation are well established, pancreatic islet survival and function in these locations remain unsatisfactory. A possible factor that might account for this outcome is local hypoxia caused by the limited blood supply. Here, we modified a prevascularized tissue-engineered chamber (TEC) that facilitated the viability and function of the seeded islets in vivo by providing a microvascular network prior to transplantation. TECs were created, filled with Growth Factor-Matrigel™ (Matrigel™) and then implanted into the groins of mice with streptozotocin-induced diabetes. The degree of microvascularization in each TECs was analyzed by histology, real-time PCR, and Western blotting. Three hundred syngeneic islets were seeded into each chamber on days 0, 14, and 28 post-chamber implantation, and 300, 200, or 100 syngeneic islets were seeded into additional chambers on day 28 post-implantation, respectively. Furthermore, allogeneic or xenogeneic islet transplantation is a potential solution for organ shortage. The feasibility of TECs as transplantation sites for islet allografts or xenografts and treatment with anti-CD45RB and/or anti-CD40L (MR-1) was therefore explored. A highly developed microvascularized network was established in each TEC on day 28 post-implantation. Normalization of blood glucose levels in diabetic mice was negatively correlated with the duration of prevascularization and the number of seeded syngeneic islets. Combined treatment with anti-CD45RB and MR-1 resulted in long-term survival of the grafts following allotransplantation (5/5, 100%) and xenotransplantation (16/20, 80%). Flow cytometry demonstrated that the frequency of CD4+Foxp3-Treg and CD4+IL-4+-Th2 cells increased significantly after tolerogenic xenograft transplantation, while the number of CD4+IFN-γ-Th1 cells decreased. These findings demonstrate that highly developed microvascularized constructs can facilitate the survival of transplanted islets in a TECs, implying its potential application as artificial pancreas in the future.
虽然临床或实验胰岛移植的场所已经建立，但这些部位的胰岛存活率和功能仍不理想。造成这种结果的一个可能因素是由于血供有限导致局部缺氧。在这里，我们对一种预先血管化的组织工程室（TEC）进行了修改，该室通过在移植前提供微血管网络，从而提高了接种胰岛的体内活力和功能。TEC 是创建的，用生长因子-Matrigel™（Matrigel™）填充，然后植入链脲佐菌素诱导糖尿病的小鼠腹股沟。通过组织学、实时 PCR 和 Western blot 分析每个 TEC 的微血管化程度。在 chamber 植入后第 0、14 和 28 天，每个 chamber 中接种 300 个同基因胰岛，在 chamber 植入后第 28 天，分别在另外的 3 个 chamber 中接种 300、200 或 100 个同基因胰岛。此外，同种异体或异种胰岛移植是解决器官短缺的一种潜在方法。因此，探索了 TEC 作为胰岛同种异体或异种移植物移植部位的可行性，并研究了用抗 CD45RB 和/或抗 CD40L（MR-1）进行治疗的效果。在 chamber 植入后第 28 天，每个 TEC 中均建立了高度发达的微血管化网络。糖尿病小鼠血糖水平的正常化与预血管化的持续时间和接种的同基因胰岛的数量呈负相关。联合使用抗 CD45RB 和 MR-1 可导致同种异体移植（5/5，100%）和异种移植（16/20，80%）后的移植物长期存活。流式细胞术表明，耐受的异种移植后，CD4+Foxp3-Treg 和 CD4+IL-4+-Th2 细胞的频率显著增加，而 CD4+IFN-γ-Th1 细胞的数量减少。这些发现表明，高度发达的微血管化构建体可以促进 TEC 中移植胰岛的存活，这暗示了其作为未来人工胰腺的潜在应用。
