ATF诱导Th1/Th2漂移构建血管化人工胰岛的研究

Diabetes has become a major killer to human health.Islet transplantation is recognized as the most promising treatment method for diabetes especially type I diabetes. However, the long-term clinical effect is not ideal, the majority of patients undergoing islet transplantation restore the insulin dependent in few years after islet transplantation. The research will provide important preclinical experimental results for the treatment of diabetes through islet transplantation.. Heme oxygenase-1( HO-1) is an important antioxidant, it can not only protect endothelial cells against high glucose and hypoxia, but also inhibit immune rejection. Our team have obtained a new artificial transcription factors (ATF), it can specifically promote the continuous expression of endogenous HO-1, EPC play an important role in promoting angiogenesis, we intend to make clear the following questions through diabetic mouse model and 3D thermosensitive hydrogel. 1.The effect and mechanism of ATF on promoting HO-1 expression in EPC and islet cells. 2.Whether ATF can protect EPC against high glucose, hypoxia injury and what is the mechanism. 3.Whether ATF can induce Th1/Th2 drift in islet and inhibit immune rejection. 4.Whether EPC and islet modified by ATF and complex with 3D thermo- sensitive hydrogel can contribute to the treatment for diabetes. This research will clarify the biological effects of ATF, and provide important pre-clinical experimental results for islet transplantation to treat diabetes.

糖尿病已成为威胁人类健康的一大杀手。胰岛移植被公认为是糖尿病尤其是I型糖尿病最具前景的治疗方法，但其远期临床效果并不理想，绝大多数接受胰岛移植的患者在几年内又恢复了胰岛素依赖。本项目针对HO-1这一重要的抗氧化酶，不但可以抑制高糖、缺氧等诱导的内皮细胞损伤，而且在降低移植物免疫排斥反应中具有重要作用，基于课题组前期获得的一种新型人工转录因子（ATF）能特异促进细胞内源性HO-1持续高表达，以及EPC促进血管新生的作用，拟通过将HO-1高表达的EPC和胰岛细胞共移植，揭示：1.HO-1在EPC促胰岛内血管快速重建、提高血管密度中的作用及机制；2.HO-1在诱导Th1/Th2漂移，抑制免疫排斥反应中的作用及机制。3.HO-1 高表达的EPC与胰岛复合水凝胶在治疗糖尿病中的作用及机制。课题的完成将为胰岛移植彻底治疗糖尿病提供重要的临床前实验结果。

胰岛移植被公认为是糖尿病尤其是I型糖尿病最具前景的治疗方法，但其远期临床效果并不理想，移植失败的原因主要在于：1.胰岛移植后，移植物内Th1/Th2细胞间平衡被打破，向Th1发生了漂移，诱发免疫排斥反应；2.移植物内血管不能快速重建，导致胰岛细胞因缺血、缺氧而大量死亡。本项目主要针对胰岛移植中这两大问题进行研究。众所周知，HO-1是重要的抗氧化酶，不但可以抑制高糖、缺氧等诱导的细胞损伤，而且在降低移植物免疫排斥反应中具有重要作用。实验中通过HO-1激动剂Copp上调细胞内HO-1水平，检测了其对MSC、胰岛对抗高糖损伤的作用；通过将胰岛细胞与单核细胞共培养，检测了HO-1对Th1及Th2细胞因子表达的影响。结果表明，HO-1高表达具有逆转Th1/Th2向Th1漂移的作用，可诱导移植胰岛耐受。为了促进移植胰岛内血管的快速重建，我们采用MSC与胰岛细胞共移植，同时为了防止细胞流失，增加移植细胞的功能，我们采用将细胞种植与3D温敏水凝胶后再移植的方法，取得了很好的效果，比对照组效果更加明显。该课题的研究为后续人工胰岛的构建提供了坚实的理论与实验基础。