DEVELOPMENT OF CELLULAR DIVERSITY IN THE COLLECTING DUCT

拟议研究的广泛目标是了解 导致细胞发育的细胞和分子机制 收集管段内和段之间的非均质性 系统。 这个项目的基础是我们隔离和培养各种 收集管的细胞类型，使用细胞特异性抗体和 细胞分选和收集导管细胞系的研究进展 这些工具，我们最近已经建立了β-嵌入细胞在 文化表现出显著的可塑性，并能产生两者 α-嵌合细胞和主细胞。这种细胞转换似乎 形成一个杂交细胞，然后形成一个不对称细胞 分裂产生两个抗原性不同的子细胞。在……里面 在这项提议中，我们计划将这些观察扩大到发展中国家。 肾脏。 Aim(1)将检验以下假设：收集的异质性 风管系统是通过细胞间的相互转换而产生的， 邻近的肾单位节段。我们将检查细胞-细胞的作用 细胞-基质相互作用对培养的集合管表型的影响 细胞，增殖率与表达序列相关 肾脏发育过程中的细胞特异性抗原；并跟随着 基因标记的细胞被重新引入发育中的肾脏。目标(2) 将检验不对称细胞分裂是一种新的假设 同时细胞分化和干细胞更新的机制和 它至少在一定程度上是由电场诱导的 膜蛋白的极化。AIM(3)建议确定 通过细胞特异性，β-嵌入细胞在肾脏发育中的作用 携带有毒基因的转基因动物的消融 β-嵌入细胞特有的调控DNA序列。 预计这些研究将扩大我们对 肾脏发育的基本机制和有助于理解 遗传性疾病的发病机制，如多囊肾病。在……里面 此外，我们认为我们计划建立的一些基本机制 探索肾脏细胞，如细胞分化和干细胞 通过细胞极化和不对称细胞分裂进行更新，被广泛地 适用于其他病理情况，如发育 疾病和恶性肿瘤。

The broad objectives of the proposed research are to understand the cellular and molecular mechanisms that lead to the development of cell heterogeneity both with and between segments of the collecting duct system. Fundamental to this project is our ability to isolate and culture various cell types of the collecting duct, using cell-specific antibodies and cell sorting, and the development of collecting duct cell lines Using these tools, we have recently established that beta-intercalated cells in culture exhibit a remarkable plasticity and can give rise to both alpha-intercalated and principal cells. This cellular conversion seems to involve formation of a hybrid cell, followed by an asymmetric cell division resulting in two antigenically different daughter cells. In this proposal we plan to expand these observations to the developing kidney. Aim (1) will test the hypothesis that the heterogeneity of the collecting duct system arises through cellular interconversion and the influence of neighboring nephron segments. We will examine the effect of cell-cell and cell-matrix interactions on the phenotype of cultured collecting duct cells, correlate proliferation rates with the sequence of expression of cell-specific antigens during kidney development; and follow the fate of genetically tagged cells reintroduced into developing kidneys. Aim (2) will test the hypothesis that asymmetric cell division is a novel mechanism for simultaneous cell differentiation and stem cell renewal and that it is, at least in part, mediated by electric field-induced polarization of membrane proteins. Aim (3) proposes to determine the role of beta-intercalated cells in kidney development, by cell-specific ablation in transgenic animals with toxic genes controlled by beta-intercalated cell-specific regulatory DNA sequences. It is anticipated that these studies will expand our knowledge of the basic mechanisms of kidney development and help to understand the pathogenesis of genetic disorders such as polycystic kidney disease. In addition, we believe that some of the fundamental mechanisms we plan to explore with kidney cells, like cell differentiation and stem cell renewal via cell polarization and asymmetric cell division, are broadly applicable to other pathological conditions such as developmental disorders and malignancies.