不同膀胱细胞外基质在膀胱应力生物学信号转导中作用的研究

Building a new bladder with tissue engineering technique is one hot point in urologic area. However, the simply static culture bladder cell with materials cannot achieve the normalization of the tissue's structure and cell's phenotype and function. The data from tissue engineering bone and blood vessels show the bio-stress is another key point to promote the tissue's structure normalization and the differentiation of cell phenotype and the maturation of cell function. Bladder is living in a fluid bio-stress environment; bio-stress is also a very important factor in its development. Cells and the extracellular components of the surrounding extracellular matrix (ECM) interact with each other, resulting in a complex interplay composed of cell-matrix interactions. Our research group have identified that the good differential phenotype and reappearance of key functional gene of the bladder cell under cyclic stretch. But the role of different bladder extracellular matrix on bladder cell response to bio-stress is not identified yet. To explore the precisely mechanism of different bladder ECM in bladder mechanotransduction, this study will apply different characteristic bio-stress to bladder cell with different ECM. The role of integrin, MAPKs, PLCγ1和Rac1 pathway will be identified, and the relation between cell's phenotype, function with ECM's production and degradation will be defined. It laid the ground for construction of functional tissue engineering bladder when we can precisely regulate bio-stress to stimulate cell-ECM interactions, promote the understanding of the mechanism of bio-stress in the diseases such as bladder outlet obstruction.

由于临床用肠道代膀胱的固有缺陷,组织工程膀胱一直是研究的焦点。但目前细胞与材料简单累加的方法不能达到整合各组分而实现结构和功能的理想化。血管及骨的研究表明：要促进细胞与材料的整合及细胞的功能分化，应力刺激十分重要。膀胱自胚胎期就处于流体应力环境，应力是其发育的重要诱导因素。我们在前期研究中也已证实应力对膀胱细胞生物学行为有重要影响,并发现细胞外基质对膀胱细胞的应力转导至关重要，单纯细胞培养与基质加细胞的复合培养模式，细胞应力反应有较大差别。但其中不同类型细胞外基质所起到的作用至今尚不清楚。因此深入研究不同细胞外基质对膀胱细胞应力感应及转导过程的影响具有重要意义。本研究拟运用程控应力加载系统，观察各类细胞外基质在膀胱应力转导中的作用和应力转导引起的细胞对细胞外基质的重塑作用，及相关信号通路。将有助于了解应力在组织重构中的作用并设计合理的组织工程膀胱构建策略，有助于了解应力在膀胱疾病中的作用。

由于临床应用肠道代膀胱的固有不足,组织工程膀胱一直是研究的焦点。但目前细胞与材料简单累加的方法不能达到整合各组分而实现结构和功能的理想化。膀胱是一个处于应力环境下的器官。生物应力对构建组织工程膀胱具有重要作用。我们研究团队证实在周期性牵张力作用下，分化良好的细胞表型以及关键的功能基因表达得到重现。并证实细胞外基质在膀胱力学信号转导中发挥重要作用。本项目着力探寻力学环境下细胞外基质对细胞特性的影响以及细胞外基质在力学信号转导中的机制。项目研究发现牵张力可以促进膀胱平滑肌细胞的细胞外基质表达，整合素α4/αv-FAK-ERK1/2信号通路在上述过程中发挥重要作用。并深入研究了力学信号向细胞内传导的途径，明确了力学环境下细胞外基质与细胞膜的连接模式。外源性细胞外基质可以加强细胞与细胞外基质之间的连接，并强化应力诱导的细胞黏附作用，并证实RhoA 和 Paxillin作为关键分子参与上述过程的调控。特别是，项目发现在膀胱出口梗阻情况下应力增高状态下，应力诱导细胞外基质在膀胱重塑中的重要作用，同时首次发现M受体阻滞剂对膀胱出口梗阻应力增高状态下的膀胱壁的细胞外基质具有显著的调控作用，对应力过高状态下的膀胱结构和功能具有保护作用，有着极重要的临床治疗指导意义。