DEVELOPING VISION--THE MECHANISM OF TISSUE REMODELING

我们的长期目标是确定发育的机制 哺乳动物眼睛中的程序性组织退化。我们将广泛地 使用分子和发育研究技术来确定 在细胞和分子水平上的回归机制。我们会 以啮齿动物眼的瞳孔膜(PM)为模型系统 用来研究组织退化。PM为学习提供了一个理想的系统 由于它的退化发生在小鼠和大鼠出生后，PM是 容易移除和可视化，总的来说，眼睛是可以接触到的 也不是必须的。具体目标： (1)探讨大鼠发育性组织重塑的机制。 眼睛在细胞水平上。在哺乳动物中，巨噬细胞已被牵连 在组织重塑方面。我们的初步数据表明，透明细胞和 眼巨噬细胞，是PM在发育过程中消退所必需的 老鼠眼的颜色。我们将同时使用转基因小鼠和眼内移植 注射作为预防眼内透明细胞活动的方法 PM回归来证实这一结果。这些实验也将使我们能够 以确定透明细胞在过程中起主动还是被动作用 组织重塑。也将调查肥大细胞的活动，因为 它们与PM在其回归过程中相关联。 (2)确定PM的消退是否涉及细胞的凋亡 组成细胞。将确定是否会有一些变化 通常与细胞凋亡(如核小体的出现)有关 阶梯)在回归过程中出现在PM的细胞中。如果细胞凋亡发生了 发生在PM回归期间，这意味着，根据初步证据， 透明细胞可以诱导靶细胞的凋亡。 (3)确定细胞因子在细胞间相互作用中的调节作用 PM消退过程中的透明细胞和靶结构。为了实现这一目标，我们 将决定之前识别的分子是否有可能 表达了调节透明细胞-靶细胞相互作用的候选细胞 有适当的模式和时机。 (4)使用体内系统证明巨噬细胞靶标 细胞间的相互作用取决于(3)中确定的分子。我们 将使用转基因小鼠和眼内注射来引入 分子特异性抑制剂，并表明它们是重塑所必需的 眼部结构。 巨噬细胞在许多疾病状态中起着中心作用，包括 炎症性疾病。此外，它是正常免疫所必需的。 功能以及伤口愈合，或“计划外”组织重塑。 研究巨噬细胞介导的眼组织退化提供了一种 独一无二的机会来了解这个细胞的正常功能 过程和潜在地应用巨噬细胞的特征行为 在一种治疗环境中。

It is our long term aim to determine the mechanism of developmentally programmed tissue regression in the mammalian eye. We will make extensive use of molecular and developmental research techniques to determine the mechanism of regression at both the cellular and molecular levels. We will use the pupillary membrane (PM) in the rodent eye as a model system in which to study tissue regression. The PM offers an ideal system for study since its regression occurs after birth in the mouse and rat, the PM is easily removed and visualized, and in general terms, the eye is accessible and non-essential. Specific aims: (1) To determine the mechanism of developmental tissue remodeling in the eye at the cellular level. In mammals, the macrophage has been implicated in tissue remodeling. Our preliminary data suggests that the hyalocyte, an ocular macrophage, is required for regression of the PM during development of the mouse eye. We will use both transgenic mice and intra-ocular injection as methods to prevent the action of hyalocytes in the eye during PM regression to confirm this result. These experiments will also allow us to determine whether the hyalocyte has an active or a passive role during tissue remodeling. Mast cell activities of will also be investigated since they are associated with the PM during its regression. (2) To determine whether regression of the PM involves apoptosis of the constituent cells. It will be determined whether a number of changes usually associated with apoptosis (such as the appearance of a nucleosomal ladder) occur in cells of the PM during regression. If apoptosis does occur during PM regression, it will imply, based on preliminary evidence, that the hyalocyte can induce apoptosis in target cells. (3) To identify cytokines that mediate the interaction between the hyalocytes and target structures during PM regression. To achieve this, we will determine whether previously recognized molecule's that are likely candidates for mediating a hyalocyte-target cell interaction are expressed with the appropriate pattern and timing. (4) To demonstrate, using an in vivo system, that the macrophage-target cell interaction is dependent upon the molecules identified in (3). We will use both transgenic mice and intra-ocular injection to introduce molecule-specific inhibitors and show they are required for remodeling ocular structures. The macrophage is a central player in many disease states including inflammatory disorders. Furthermore, it is required for normal immune function as well as wound healing, or "unscheduled" tissue -remodeling. Studying ocular tissue regression that is macrophage-mediated offers a unique opportunity to learn about the function of this cell in a normal process and potentially to apply the characteristic actions of macrophages in a therapeutic setting.