Manipulating the matrix to improve arteriovenous fistula patency

项目摘要 人类疾病的几种常见疗法的基础是使用静脉作为导管， 增加血流量，如动静脉内瘘（AVF），血液透析的首选通路。然而，在这方面， AVF的成熟度和通畅性较差，尤其是在女性中，需要额外的重做手术， 手术，反映了我们对静脉重塑生物学的不完善理解，导致成功的 静脉适应动脉环境。这种知识差距造成了对小说的需求得不到满足。 本发明涉及增强静脉重塑并由此增加静脉导管的成功临床使用的方法。 成功的静脉重塑需要细胞外基质（ECM）的沉积，从而使机械性血管重塑成为可能。 抵抗每周3次用大口径针头穿刺AVF壁的血液透析程序的强度。 转化生长因子（TGF）-β1调节许多细胞功能，包括ECM沉积和细胞外基质（ECM）沉积。 重塑我们提出了令人兴奋的新数据：1）我们创新的AVF小鼠模型忠实地再现了 人类AVF成熟，包括约1/3的失败率; 2）患有AVF的雌性小鼠的 与雄性小鼠相比，剪切应力; 3）我们可以在体内操纵TGF-β1功能，TGF-β1是 成功的早期AVF重塑; 4）在失败的小鼠AVF中，ECM增加，晚期TGF-β1表达 5）手术后人AVF中smad 2/tak 1磷酸化水平增加 6）我们开发了一种创新的纳米颗粒工具来操纵体内TGF-β1信号传导。 我们的数据表明，瘘管的手术形成通过smad 2/3刺激早期TGF-β1的活化， 和/或tak 1磷酸化，这对于成功的早期静脉适应和AVF成熟至关重要。我们 假设旺盛晚期TGF-β1活性导致过度ECM沉积和新生内膜 增生导致AVF失败。降低晚期TGF-β1活性可减少ECM沉积和新生内膜增生。 增生，从而改善AVF通畅性。我们将使用我们创新的体内模型，以及一种新颖的 生物反应器和分子工具，以测试我们的假设与以下具体目标： 目的一：探讨体外TGF-β信号通路和体内AVF重构是否存在性别差异。 目的II：确定减少晚期TGF-β1信号传导的最佳递送，从而增强静脉适应性， 改善AVF通畅性。 目的III：探讨TGFβ1介导AVF重构的机制是否与smad 2或tak 1有关。 这项工作将通过确定过度的TGF-β活性是否会导致AVF产生持久的影响 失败，以及降低晚期TGF-β活性是否是临床转化为增强AVF的有价值策略 通畅性我们还将确定女性AVF成熟度的降低是否是由于静脉 重塑或新生内膜增生增加。我们使用创新的策略和新的工具来操纵 TGF-β信号传导改变血管壁组成和强度，从而改善AVF通畅性。

Project Summary A cornerstone of several common therapies for human diseases is the use of a vein as a conduit to increase blood flow such as the arteriovenous fistula (AVF), the preferred access for hemodialysis. However, the poor maturation and patency of AVF, especially in women and requiring additional re-do procedures and surgery, reflects our imperfect understanding of the biology of venous remodeling that leads to successful venous adaptation to the arterial environment. This knowledge gap creates an unmet need for novel approaches to enhance venous remodeling and thereby to increase successful clinical use of venous conduits. Successful venous remodeling requires deposition of extracellular matrix (ECM), enabling mechanical strength to resist hemodialysis procedures that puncture the AVF wall with large bore needles 3 times a week. Transforming growth factor (TGF)-β1 regulates numerous cellular functions, including ECM deposition and remodeling. We present exciting new data that: 1) our innovative mouse model of AVF faithfully recapitulates human AVF maturation including an ~1/3 failure rate; 2) female mice with AVF have diminished magnitudes of shear stress compared to male mice; 3) we can manipulate TGF-β1 function in vivo and TGF-β1 is required for successful early AVF remodeling; 4) in failed mouse AVF there is increased ECM, late TGF-β1 expression and smad2/tak1 phosphorylation; 5) there is increased smad2/tak1 phosphorylation in human AVF surgically removed for failure; 6) we developed an innovative nanoparticle tool to manipulate TGF-β1 signaling in vivo. Our data suggest that surgical creation of a fistula stimulates early TGF-β1 activation via smad2/3 and/or tak1 phosphorylation that is critical for successful early venous adaptation and AVF maturation. We hypothesize that exuberant late TGF-β1 activity results in excessive ECM deposition and neointimal hyperplasia causing AVF failure. Reducing late TGF-β1 activity should reduce ECM deposition and neointimal hyperplasia, thereby improving AVF patency. We will use our innovative in vivo model, as well as a novel bioreactor and molecular tools, to test our hypothesis with the following specific aims: Aim I: Determine whether there are sex differences in TGF-β signaling in vitro and AVF remodeling in vivo. Aim II: Determine optimal delivery to reduce late TGF-β1 signaling thereby enhancing venous adaptation and improving AVF patency. Aim III: Determine whether smad2 or tak1 function is a mechanism of TGFβ1-mediated AVF remodeling. This work will have lasting impact by establishing whether excessive TGF-β activity leads to AVF failure, and whether reducing late TGF-β activity is a valuable strategy for clinical translation to enhance AVF patency. We will also determine whether the reduced AVF maturation in women is due to insufficient venous remodeling or increased neointimal hyperplasia. We use an innovative strategy and novel tools to manipulate TGF-β signaling to alter vessel wall composition and strength and thereby improve AVF patency.