Division of Transplantation Madison, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA.
Department of Allied Health, University of South Alabama, Mobile, Alabama, USA.
Cell Transplant. 2017 Nov;26(11):1742-1754. doi: 10.1177/0963689717727542.
Long-term graft survival is an ongoing challenge in the field of islet transplantation. With the growing demand for transplantable organs, therapies to improve organ quality and reduce the incidence of graft dysfunction are of paramount importance. We evaluated the protective role of a recombinant DNA repair protein targeted to mitochondria (Exscien I-III), as a therapeutic agent using a rodent model of pancreatic islet transplantation. We first investigated the effect of therapy on isolated rat islets cultured with pro-inflammatory cytokines (interleukin-1 β, interferon γ, and tumor necrosis factor α) for 48 h and documented a significant reduction in apoptosis by flow cytometry, improved viability by immunofluorescence, and conserved functional potency in vitro and in vivo in Exscien I-III-treated islets. We then tested the effect of therapy in systemic inflammation using a rat model of donor brain death (BD) sustained for a 6-h period. Donor rats were allocated to 4 groups: (non-BD + vehicle, non-BD + Exscien I-III, BD + vehicle, and BD + Exscien I-III) and treated with Exscien I-III (4 mg/kg) or vehicle 30 min after BD induction. Sham (non-BD)-operated animals receiving either Exscien I-III or vehicle served as controls. Islets purified from BD + Exscien I-III-treated donors showed a significant increase in glucose-stimulated insulin release in vitro when compared to islets from vehicle-treated counterparts. In addition, donor treatment with Exscien I-III attenuated the effects of BD and significantly improved the functional potency of transplanted islets in vivo. Our data indicate that mitochondrially targeted antioxidant therapy is a novel strategy to protect pancreas and islet quality from the deleterious effects of cytokines in culture and during the inflammatory response associated with donation after BD. The potential for rapid translation into clinical practice makes Exscien I-III an attractive therapeutic option for the management of brain-dead donors or as an additive to islets in culture after isolation setting.
胰岛移植领域面临的一个持续挑战是长期移植物存活。随着对可移植器官需求的增长，提高器官质量和降低移植物功能障碍发生率的治疗方法至关重要。我们使用啮齿动物胰岛移植模型评估了靶向线粒体的重组 DNA 修复蛋白（Exscien I-III）作为治疗剂的保护作用。我们首先研究了治疗对用促炎细胞因子（白细胞介素-1β、干扰素γ和肿瘤坏死因子-α）培养 48 小时的分离大鼠胰岛的影响，并通过流式细胞术记录到凋亡明显减少、免疫荧光法显示活力提高、以及 Exscien I-III 处理的胰岛在体外和体内保留功能活力。然后，我们使用大鼠供体脑死亡（BD）模型测试了治疗对全身炎症的影响，BD 持续 6 小时。将供体大鼠分为 4 组：（非-BD+载体、非-BD+Exscien I-III、BD+载体和 BD+Exscien I-III），并在 BD 诱导后 30 分钟用 Exscien I-III（4mg/kg）或载体治疗。接受 Exscien I-III 或载体的非-BD 手术操作的假手术（非-BD）动物作为对照。与接受载体处理的胰岛相比，来自接受 Exscien I-III 治疗的供体的胰岛在体外显示出葡萄糖刺激的胰岛素释放显著增加。此外，供体用 Exscien I-III 治疗可减轻 BD 的影响，并显著改善体内移植胰岛的功能活力。我们的数据表明，靶向线粒体的抗氧化治疗是一种保护胰腺和胰岛质量的新策略，可以防止细胞因子在培养中和与 BD 后供体相关的炎症反应中产生的有害影响。这种治疗方法有可能迅速转化为临床实践，使 Exscien I-III 成为管理脑死亡供体的一种有吸引力的治疗选择，或者作为胰岛离体培养后的附加物。
