STROMAL/EPITHELIAL INTERACTIONS IN THE BLADDER

膀胱中的间质/上皮相互作用

• 批准号: 2905871
• 负责人: GERALD R CUNHA
• 金额: $ 19.26万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2905871
• 关键词: RNase protection assay; biological signal transduction; cell cell interaction; cell differentiation; connective tissue stroma; epidermal growth factor; gene targeting; growth factor; hormone regulation /control mechanism; immunocytochemistry; in situ hybridization; laboratory mouse; laboratory rat; mesenchyme; muscle hypertrophy; paracrine; receptor expression; smooth muscle; stromal cells; transforming growth factors; urinary bladder epithelium; urinary tract obstruction; wound healing

The main goal of this proposal is to investigate the role of growth factors as mediators of stromal-epithelial interactions in bladder development and dysfunction. Our previous work has shown that bladder smooth muscle (SM) is induced from undifferentiated bladder mesenchyme by bladder epithelium. This proposal is based on the hypothesis that interactions between bladder epithelial and mesenchymal cells regulate and maintain SM cell differentiation and growth in developing and dysfunctional bladders. These cell-cell interactions are mediated by the local production and action of growth factors an other paracrine acting mediators. This hypothesis will be tested using an experimental model of urethral obstruction in which bladder SM responds by undergoing hypertrophy. We have also created an experimental model of bladder augmentation in which a grafted acellular bladder tissue matrix serves as a scaffold for the ingrowth of native bladder smooth muscle and urothelial cells. During normal bladder development and in two experimental systems, cellular signaling mechanisms regulating both normal and abnormal growth and differentiation of bladder SM will be examined through pursuit of the following specific aims. (Specific aim "1) Role of growth factors as mediators of cell-cell interactions in normal bladder development and during bladder round repair. Expression of growth factors (TGF-alpha, EGF, KGF, and TGFbeta1, beta2 and beta3) and growth factor receptors will be defined in normal bladder development and during bladder wound repair by RNase protection and localized by in-situ hybridization and immunohistochemistry. (Specific aim #2) Role of growth factors and cell- cell signaling in pathogenesis of bladder hypertrophy resulting from partial obstruction of the bladder. This specific aim will be pursued by defining growth factor and growth factor receptor expression following partial bladder obstruction in rats. The hypothesis of this specific aim is that SM cells are direct targets of the physical signal eliciting fibromuscular hypertrophy and that diffusible growth factors. (TGFalpha, EGF, KGF, TGFbeta1, beta2 and beta3) are involved. To accomplish this specific aim chimeric bladders will be surgically created by grafting whole embryonic bladders or strips of neonatal or adult bladders (epithelium intact or removed) into the sub-detrusor space of adult bladders. This unique experimental design will allow study of SM development and hypertrophy in bladders from transgenic mice in which growth factor genes have been deleted or impaired (TGFalpha knockout, EGF receptor knockout, TGFbeta1 knockout and FGFR2 dominant negative (Keratin 14 promoter) mice). (Specific aim #3) Use of an acellular bladder matrix patch to study normal and abnormal development of the bladder. The strategy of this specific aim is to characterize detrusor neo-formation and fibromuscular hypertrophy following grafting of acellular bladder matrix. Additional studies will assess regional and temporal differences in growth factor expression during bladder regeneration in bladders grafted with acellular bladder matrix. Finally, the performance of transgenic mouse bladder transplants during matrix-driven bladder regeneration will elucidate the role of growth factors in bladder regeneration. The long-term objective of this research is to develop effective therapeutic strategies for treating bladder dysfunction based upon stromal-epithelial interactions.

这项提案的主要目标是调查生长因子的作用 作为膀胱发育中基质-上皮相互作用的介质， 功能障碍 我们以前的工作表明，膀胱平滑肌（SM） 是由膀胱上皮未分化的膀胱间充质诱导的。 该建议是基于这样的假设，即膀胱与膀胱之间的相互作用 上皮细胞和间充质细胞调节和维持SM细胞 在发育和功能障碍的膀胱中的分化和生长。 这些 细胞间相互作用是由局部产生和作用的 生长因子和其他旁分泌作用介质。 这一假设将 使用尿道阻塞的实验模型进行测试，其中 膀胱SM通过经历肥大来响应。 我们也创造了一个 膀胱增大的实验模型中， 膀胱组织基质作为支架用于天然的 膀胱平滑肌和尿路上皮细胞。 在正常膀胱发育过程中，在两个实验系统中， 调节正常和异常生长的信号传导机制， 膀胱SM的分化将通过追求 具体目标。 （具体目标“1）生长因子的作用 正常膀胱发育中细胞-细胞相互作用的介质， 在膀胱圆形修复术中。 生长因子（TGF-α，EGF， KGF和TGF β 1、β 2和β 3）和生长因子受体将被 在正常膀胱发育和膀胱伤口修复期间定义为 RNA酶保护和通过原位杂交定位， 免疫组化 （具体目标#2）生长因子和细胞的作用 细胞信号转导在膀胱肥大发病机制中的作用 膀胱部分梗阻。 为实现这一具体目标， 定义生长因子和生长因子受体表达， 大鼠部分膀胱梗阻。 这一特定目标的假设 SM细胞是物理信号引发的直接目标， 纤维肌肥大和可扩散生长因子。 （TGF α， EGF、KGF、TGFbeta 1、beta2和beta3）都参与其中。 为了实现这一 通过移植整个膀胱， 胚胎膀胱或新生儿或成人膀胱（上皮 完整或移除）进入成人膀胱的逼尿肌下空间。 这 独特的实验设计将允许研究SM的发展， 膀胱肥大的转基因小鼠，其中生长因子基因 已经被删除或受损（TGF α敲除，EGF受体敲除， TGF β 1敲除和FGFR 2显性阴性（角蛋白14启动子）小鼠）。 （具体目标#3）使用脱细胞膀胱基质贴片来研究正常的膀胱组织。 膀胱发育异常 这一具体目标的战略 逼尿肌新生和纤维肌肥大 移植无细胞膀胱基质后。 其他研究将 评估生长因子表达的区域和时间差异， 脱细胞膀胱基质移植的膀胱再生。 最后，转基因小鼠膀胱移植的表现， 基质驱动的膀胱再生将阐明生长的作用 影响膀胱再生的因素 这项研究的长期目标是 是开发有效的治疗策略， 基于基质-上皮相互作用的功能障碍。