基于“药-自组装短肽-功能肽复合物”结构构建的区域靶向双药纳米纤维对缺血再灌注肾损伤保护作用及机制

It is reported that FTY720 could protect from ischemia referpusion injury by activating S1P1Rs in the membrane of tubular epithelial cells. Recent studies show that the elevation of intracellular ROS level in IRI could decrease the sensitivity of S1P1Rs to FTY720. If we lower the level of ROS by a ROS scavenger, Resveratrol, the sensitivity of S1P1Rs to FTY720 will be restored to generate the strongest synergistic anti-IRI effect. Moreover, co-delivery of synergistic drugs by nano-delivery system will combine the advantages of nano-drug systems with the synergism. To overcome the shortcomings of traditional polymeric carriers, novel nano-drug delivery system was constructed based on the concept of “drug-self assembled peptide-functional peptide”. We linked FTY720 with RGD and FFE to generate novel drug carrier and encapsulate Res as another model drug. RGD is able to help the nano-system target the area of IRI while FFE is good at self assemble into nanofibers. The synergistic anti-IRI effect of this novel co-drug loaded nanofiber was evaluated in in vitro and in vivo IRI models to elucidate the possible mechanisms through ROS scavenging to restoration of S1P1Rs sensitivity to FTY720.

摘要： FTY720能激活肾小管上皮细胞1-磷酸鞘氨醇受体（S1P1Rs）从而减轻缺血再灌注损伤（IRI）。但S1P1Rs对FTY720的敏感性与IRI时异常升高的活性氧（ROS）水平呈明显负相关。拟采用抗氧化剂白藜芦醇减少ROS生成使S1P1Rs恢复敏感性，以达到两药协同保护效应最大化。更重要的是，我们采用纳米递药体系将具有协同抗IRI的双药共同投递使双药的协同作用与载药体系高效低毒的优势相结合。为克服传统高分子材料作为药物载体的缺陷，我们基于“药-自组装短肽-功能肽复合物”结构在FTY720上偶联IRI区域靶向功能的精氨酸-甘氨酸-天冬氨酸三肽RGD及具有纳米纤维自组装能力的二苯基丙氨酸二肽作为药物载体负载白藜芦醇，构建双药序贯释放的纳米纤维递药体系，并利用RGD来增加纳米纤维对IRI部位的靶向性。在体内外模型上考察其协同保护效果，并探讨基于“抗氧化后S1P1Rs复敏”介导的协同机制。

FTY720能激活肾小管上皮细胞1-磷酸鞘氨醇受体（S1P1Rs）从而减轻缺血再灌注损伤（IRI）。但S1P1Rs对FTY720的敏感性与IRI时异常升高的活性氧（ROS）水平呈明显负相关。本项目采用抗氧化剂白藜芦醇(RES)减少ROS生成使S1P1Rs恢复敏感性，以达到两药协同保护效应最大化。更重要的是，我们采用纳米递药体系将具有协同抗IRI的双药共同投递使双药的协同作用与载药体系高效低毒的优势相结合。在此基础上，为了克服传统高分子材料作为药物载体的缺陷，我们基于“药-自组装短肽-功能肽复合物”结构在FTY720上偶联IRI区域靶向功能的精氨酸-甘氨酸-天冬氨酸三肽RGD及具有纳米纤维自组装能力的二苯基丙氨酸二肽作为药物载体负载白藜芦醇，并利用RGD来增加纳米纤维对IRI部位的靶向性，构建了双药序贯释放的纳米纤维递药体系。最后，在体内外模型上考察其协同保护效果，并探讨基于“抗氧化后S1P1Rs复敏”介导的协同机制。我们的结果发现，该纳米纤维递药体系具有明显的肾脏靶向作用，能保证RES的优先释放和作用发挥。进一步我们发现其机制与调控S1P1Rs下游PI3K/Akt通路，减少ROS及炎症因子IL-6、 IL-1 β、TNF-α释放和细胞凋亡，进而达到最佳的两药协同保护效果有关。