Improving marginal allograft outcomes through cell junction stabilization in transplantation

项目摘要/摘要：移植是治疗终末期肾病的一种非常成功的疗法，但 是可用的供体器官的严重短缺，迫使人们使用低质量的肾脏来挽救 病人的生命。延长捐赠者标准的同时，越来越多的人认识到，与 器官捐赠、采购和储存对移植后的结果有很大影响。与心不同 移植后，肾脏捐赠者可以从各种来源获得，包括活体捐赠者，捐献后 脑死亡，以及心脏死亡后的捐献。然而，绝大多数肾脏是从死者那里捐赠的。 脑死亡或心脏死亡后的捐赠者和捐赠者容易导致较差的移植后结果。 器官移植固有的问题，如缺血和长时间的冷藏，也会产生负面影响 并对供体肾脏造成无法弥补的损害。已知这些损伤事件会引起内皮细胞 (EC)功能障碍、炎症和器官损伤，植入后因缺血而进一步加重 再灌注损伤(IRI)，同时也为供体器官的同种免疫识别做好准备。在冷藏期间 通过减缓新陈代谢以防止细胞死亡，极大地促进了身体肾脏的移植 死亡，目前的配方并不能最大限度地减少与冷藏或缺血再灌注相关的器官损伤 受伤。血管内皮细胞，作为同种异体移植物和受体之间的动态界面，是 最初的目标是对移植物健康和功能产生不利影响的有害事件。由于缝隙和紧密连接 调节EC功能，促进内皮分子和细胞完整性的治疗策略 对供者肾脏的移植可以排除造成同种异体移植损伤和失败的机制。第一个字符串 Research Inc.已经鉴定、表征和临床评估了一种新的连接蛋白43的多肽模拟物， α-连接蛋白羧基末端(Act1)，在创伤过程中稳定内皮细胞的缝隙和紧密连接 愈合过程，导致细胞通讯的协调，抑制炎症反应， 减少免疫细胞的渗透，增强再生能力。第1幕S小巧、稳定、易溶的设计 促进直接转运到细胞内进行细胞内药物输送。临床相关的初步研究 肾、心和肺移植模型显示ACT1补充到标准护理器官 保存液稳定细胞连接，保护EC免受IRI和延长寒冷的伤害 储存时间。我们假设冷保存会导致细胞连接损伤，从而导致EC 再灌注时的功能障碍、炎症和肾脏损害，以及补充 治疗性Act1多肽到标准护理保存液将保存细胞连接，从而 改善肾脏健康和功能，带来更好的移植后结果。在这里，我们建议 体外ACT1预处理对供体肾功能、炎症状态和组织的影响 使用临床相关的猪肾移植模型和低质量的人肾进行损伤。

Project Summary/Abstract: Transplantation is a highly successful therapy for end-stage renal disease but there is a significant shortage of available donor organs that has forced utilization of low-quality kidneys to save patient’s lives. Extending the donor criteria has coincided with a growing appreciate that factors associated with organ donation, procurement and storage greatly affect post-transplantation outcomes. Unlike heart transplantation, kidney donors can be derived from a variety of sources that include living donors, donation after brain death, and donation after cardiac death. However, the vast majority of kidneys are donated from deceased donors and donation after brain death or after cardiac death predispose poorer post-transplantation outcomes. Problems inherent to organ transplantation, such as ischemia and extended cold storage, also negatively affect and cause irreparable damage to the donor kidney. These injurious events are known to elicit endothelial cell (EC) dysfunction, inflammation, and organ injury that are further exacerbated upon implantation by ischemia reperfusion injury (IRI) while also priming the donor organ for alloimmune recognition. While cold preservation has greatly facilitated the use of cadaveric kidneys for transplantation by slowing metabolism to prevent cell death, current formulations do not minimize organ injury associated with cold storage or ischemia reperfusion injury. Vascular endothelum, which serves as a dynamic interface between the allograft and the recipient, is the initial target of the deleterious events that adversely affect graft health and function. Since gap and tight junctions regulate EC functionality, therapeutic strategies that promote the molecular and cellular integrity of endothelium of donor kidneys could preclude the mechanisms responsible for allograft damage and failure. FirstString Research Inc. has identified, characterized, and clinically-evaluated a novel peptide mimetic of connexin43, alpha-Connexin Carboxy-Terminal (aCT1), that stabilizes the gap and tight junctions of ECs during wound healing processes, leading to coordination of cellular communication, dampened inflammatory responses, reduced immune cell infiltrate, and enhanced regenerative properties. aCT1’s small, stable, soluble design facilitates direct translocation into cells for intracellular drug delivery. Preliminary studies in clinically relevant models of kidney, heart, and lung transplantation reveal that aCT1 supplementation to standard-of-care organ preservation solutions stabilizes cellular junctions to protect EC from injurious effects of IRI and extending cold storage time. We hypothesize that cold preservation induces cell junction damage, which leads to EC dysfunction, inflammation, and renal damage upon reperfusion, and that supplementation of the therapeutic aCT1 peptide to standard of care preservation solution will preserve cell junctions, thereby improving renal health and function leading to superior post-transplantation outcomes. Here we propose to investigate the effect of ex vivo aCT1 pretreatment on donor kidney function, inflammatory state, and tissue injury using clinically relevant pig kidney transplantation models and low-quality human kidneys.