The Role of PTEN in B-cell regeneration through epithelial-mesenchymal transition

描述（由申请人提供）：I型糖尿病的标志是细胞的损失。为了开发治疗方法，我们需要了解这些细胞如何再生。这项提案的目标是了解细胞再生是如何调节的。我们已经集中在PTEN（磷酸酶和张力蛋白同源物10号染色体上删除），并表明，删除Pten导致胰岛质量增加。我们推测，PTEN缺乏通过调节胰岛细胞动力学和可塑性增加胰岛质量。为了验证这一假设，我们设定了两个具体目标。在Aim 1中，我们将确定PTEN对胰岛质量的影响是否是细胞自主的。将使用两种方法来测试PTEN对细胞再生的自主性质。使用PtenloxP/loxP; RosalacZ; Rip-Cre+小鼠进行谱系追踪以研究PTEN在细胞增殖中的作用将是第一种方法。以前，我们已经观察到，PTEN缺乏导致胰岛质量增加，同时胰岛附近增殖增加。在这项研究中，我们将确定这些增殖的胰岛周细胞是否来源于胰岛细胞，以及它们是否有助于胰岛再生。为了进一步测试PTEN的作用是否对<$-细胞是细胞自主的，我们将确定PTEN对<$-细胞再生的作用是否依赖于其在发育中的作用。为此，我们将使用我们已经生成的PtenloxP/loxP; RosalacZ; Rip-CreER+模型来诱导成熟细胞中的Pten缺失。在Aim 2中，我们将研究PTEN诱导的细胞再生的机制。我们已经观察到Pten突变胰腺中间充质细胞形成增加。因为老鼠？- 细胞很可能是自我再生的，这些间充质细胞很可能是处于去分化过程中的-细胞，因为它们不表达胰岛素。为了解决PTEN如何调节<$-细胞可塑性，我们将研究PTEN对<$-细胞再生中上皮间质转化（EMT）的作用。EMT被认为是一种机制，即细胞可以用来再生。我们将使用PtenloxP/loxP; RosalacZ; Rip-Cre+小鼠的谱系追踪来确定这些间充质细胞是否确实是经历EMT的<$-细胞以及它们是否有助于<$-细胞再生。总之，本申请集中于细胞再生的机制。本研究的结果将为靶向PI 3 K/AKT信号通路治疗I型糖尿病的可行性提供机制分析。这项研究的重点是了解胰腺细胞再生的机制。刺激细胞再生是开发针对I型糖尿病的药物治疗的重要目标。这项研究提供了一个机制分析的作用，PTEN，一个关键的生长调节因子，在细胞再生。如果这一假设得到证实，这项研究将为设计靶向PTEN调节的PI 3 K/AKT通路以刺激细胞再生的药物提供分子基础。

DESCRIPTION (provided by applicant): The hallmark of type I diabetes is the loss of ¿-cells. In order to develop therapies, we need to understand how these cells can be regenerated. The goal of this proposal is to understand how ¿-cell regeneration is regulated. We have focused on PTEN (phosphatase and tensin homologue deleted on chromosome 10) and shown that deletion of Pten leads to increased islet mass. We hypothesize that PTEN deficiency increases islet mass by regulating ¿-cell dynamics and plasticity. To test this hypothesis, we have set two specific aims. In Aim1, we will determine whether the effect of PTEN on islet mass is cell autonomous to ¿-cells. Two approaches will be used to test the autonomous nature of PTEN on ¿-cell regeneration. Lineage tracing using PtenloxP/loxP; RosalacZ; Rip-Cre+ mouse to investigate the role of PTEN in ¿-cell proliferation will be the first approach. Previously, we have observed that PTEN deficiency leads to increased islet mass in conjunction with an increased proliferation near the islets. In this study, we will determine whether these proliferating peri-islet cells originate from ¿-cells and whether they contribute to islet regeneration. To further test if the effect of PTEN is cell autonomous to ¿-cells, we will determine whether the effect of PTEN on ¿-cell regeneration is dependent on its role in development. To do this, we will use the PtenloxP/loxP; RosalacZ; Rip-CreER+ model that we have generated to induce Pten deletion in mature ¿-cells. In Aim2, we will investigate the mechanism for PTEN induced ¿-cell regeneration. We have observed increased mesenchymal cell formation in the Pten mutant pancreas. Since mouse ¿-cells are most likely self regenerating, it is likely that these mesenchymal cells are ¿-cells in the process of dedifferentiation as they do not express insulin. To address how PTEN regulates ¿-cell plasticity, we will investigate the role of PTEN on epithelial mesenchymal transition (EMT) in ¿-cell regeneration. EMT has been suggested to be one mechanism that ¿-cells may use to regenerate. We will use lineage tracing with the PtenloxP/loxP; RosalacZ; Rip-Cre+ mouse to determine if these mesenchymal cells are indeed ¿-cells going through EMT and whether they contribute to ¿-cell regeneration. In summary, this application is focused on the mechanism of ¿-cell regeneration. The result of this study will provide a mechanistic analysis of the feasibility of targeting the PI3K/AKT signal pathway in order to treat type I diabetes. The proposed study is focused on understanding the mechanism for pancreatic ¿-cell regeneration. Stimulating ¿-cell regeneration is an important goal for developing drug treatments targeted at type I diabetes. The proposed study provides a mechanistic analysis of the role of PTEN, a key growth regulator, in ¿-cell regeneration. If the hypothesis is proven, this study will provide a molecular basis for drugs designed to target the PTEN regulated PI3K/AKT pathway in order to stimulate ¿-cell regeneration.