Stem Cell Therapy Combined with Growth Factors for Stress Urinary Incontinence

描述（由申请人提供）：压力性尿失禁（SUI）严重影响美国多达1300万人的生活质量。其病理过程包括括约肌组织功能障碍、慢性神经损伤和局部血供不足。目前的治疗方法有药物治疗、吊带手术和注射填充剂。以细胞为基础的治疗是恢复尿道括约肌功能缺陷的一种很有前途的治疗方法。我们已经证明成人干细胞存在于人类尿液中。这些细胞被称为尿源性干细胞（USCs），具有强大的增殖潜能和多潜能分化的干细胞特征。这些细胞可以通过简单、安全、无创和低成本的方法获得，从而避免了从其他来源获取干细胞相关的不良事件。通过血管生成来改善尿道括约肌微环境对于干细胞治疗的成功至关重要，干细胞的成功取决于细胞的存活、生长和分化，以及宿主细胞的募集，以帮助尿道括约肌组织修复。需要采用一种更安全的方法来递送生长因子以增强干细胞壁龛（微环境）。胰岛素样生长因子1 （IGF-1）促进损伤后肌肉生成，诱导神经再生，并刺激血管生成。我们最近的研究表明，USCs分泌高水平的IGF1和IGF结合蛋白1，植入USCs可显著增强阴道膨胀后的体内括约肌功能。此外，我们证明了海藻酸盐微珠递送系统可以控制生长因子的释放，从而提高移植干细胞在体内的存活和分化。因此，该项目的最终目标是开发一种治疗方法来改善干细胞治疗的结果，并最终导致治疗和可能治愈尿失禁。为此，我们将制定连贯的实验方案来研究干细胞和生长因子的结合递送，以增强血管生成，促进细胞存活、生长、肌源性分化和体内神经支配。我们假设海藻酸盐微球释放的IGF1可以通过akt介导的信号通路提高细胞存活率，促进USCs的长入和分化，招募驻留细胞参与尿道括约肌组织的修复。为了验证这些假设，我们提出以下具体目标：目标1。阐明USCs在无胸性SUI大鼠模型中改善括约肌组织修复的机制。目标2。测定海藻酸盐微球控释IGF1对体内括约肌组织修复的影响。目标3。测定USCs和IGF1联合使用对阴道扩张后尿道括约肌再生的影响。系统的方法将为我们提供一个关键的工具来研究如何操纵干细胞和IGF1之间的生物相互作用，损害尿道组织再生。该项目的成功完成将为自体USCs治疗尿失禁的临床试验制定治疗策略。

DESCRIPTION (provided by applicant): Stress urinary incontinence (SUI) severely affects the quality of life of up to 13 million people in the USA. Its pathological processes include dysfunctional sphincter muscle tissue, chronic nerve injury, and poor regional blood supply. Some current therapeutic approaches are pharmacotherapy, sling surgery, and injection of bulking agents. Cellular-based therapy is a promising alternative method to restore deficient urethral sphincter function in the treatment of SUI. We have demonstrated that adult stem cells exist in human urine. These cells, termed urine-derived stem cells (USCs), possess stem cell characteristics with robust proliferative potential and multi-potential differentiation. These cell can be obtained using simple, safe, non-invasive and low-cost procedures, thus avoiding the adverse events associated with obtaining stem cells from other sources. Improving the urethral sphincter microenvironment by angiogenesis is critical for success of stem cell therapy determined by cell survival, ingrowth and differentiation, and host cell recruitment to aid urethra sphincter tissue repair. It is desirable to employ a safer approach to growth factor delivery to enhance the stem cell niches (microenvironment). Insulin-like growth factor 1 (IGF-1) promotes myogenesis and induces nerve regeneration after injury, and it also stimulates angiogenesis. Our recent studies demonstrated that USCs secreted high levels of IGF1 and IGF binding protein 1, and implanted USCs significantly enhanced sphincter function after vaginal distention in vivo. Moreover, we demonstrated that an alginate microbead delivery system is feasible to control growth factor release and thereby enhance survival and differentiation of grafted stem cells in vivo. Thus, the ultimate goal of this project is to develop a therapeutic approach to improve the outcomes of stem cell therapy and eventually lead to treatments and possibly cures for urinary incontinence. To do so, we will develop coherent experimental protocols to study a combination of stem cells and growth factor delivery to enhance angiogenesis and promote cell survival, growth, myogenic differentiation, and innervation in vivo. We hypothesize that IGF1 released from alginate microbeads can improve cell survival, enhance ingrowth and differentiation of USCs, and recruit resident cells to take part in urethral sphincter tissue repai via Akt-mediated signaling pathways. To test these hypotheses, we propose the following Specific Aims: Aim 1. Elucidate the mechanisms by which USCs improve sphincter tissue repair in an athymic rat model of SUI. Aim 2. Determine the effects of controlled release of IGF1 from alginate microbeads on sphincter tissue repair in vivo. Aim 3. Determine the impact of USCs and IGF1 in combination on urethral sphincter regeneration after vaginal distention. The systematic approach will provide us with a critical tool to investigate how to manipulate biological interactions between stem cells and IGF1 that impair urethral tissue regeneration. Successful completion of this project will develop a therapeutic strategy for clinical trials of autologous USCs for urinary incontinence.