MAPK regulation of the epigenome during mast cell differentiation

人类和其他动物的骨髓含有干细胞，可以成为免疫系统的各种细胞类型。这个过程被称为分化，它创造了特定类型的免疫细胞，并要求由细胞信号事件启动的基因表达发生变化。对干细胞灵活特性至关重要的基因被关闭，而对成熟免疫细胞重要的基因被激活。这些基因表达的变化涉及到染色质或DNA的稳定结构变化，这一过程被称为表观基因调控。通过非常紧密地包装特定基因以使它们在染色质中不可访问，而通过更宽松的包装来打开其他基因以便于访问。组蛋白乙酰化和DNA甲基化的过程是主要贡献者。肥大细胞是一种免疫细胞类型，在防御中发挥重要作用，但我们并不完全了解它们与干细胞的区别。我们所知道的一种对肥大细胞分化很重要的信号类型是丝裂原活化蛋白激酶(MAPK)途径。MAPK信号与其他类型细胞分化过程中的表观遗传学变化有关，我们知道它是激活的，对肥大细胞的分化很重要。虽然在肥大细胞分化过程中发现了一些表观遗传学变化，但控制肥大细胞分化的信号尚不清楚。这些事件之间的联系代表了我们在理解上的一个重大差距，并突显了我提议的研究的新颖性。我的研究团队已经确定了肥大细胞分化过程中几种表观遗传酶的激活。我们假设MAPK信号有助于表观遗传酶的激活，从而导致肥大细胞基因在分化过程中被打开，干细胞基因被关闭。*为了确定MAPK信号在肥大细胞分化表观遗传学中的作用，我们将进行实验，以满足以下三个目标：*1)确定MAPK信号在肥大细胞分化过程中组蛋白乙酰化的重要性。*2)评估MAPK信号在肥大细胞分化过程中DNA甲基化中的作用。*3)检测MAPK蛋白在肥大细胞分化和激活过程中进入细胞核的意义。预期意义：拟议研究的总体目标是提高我们对MAPK蛋白如何在肥大细胞分化过程中调节细胞核内基因表达的理解。MAPK信号在多种细胞功能中高度保守和重要，包括生长、分化、发育、应激反应和细胞死亡。考虑到这种广泛的功能作用，所获得的结果可能会有广泛的生物学应用。这项工作将加强我们对细胞信号机制和表观遗传基因调控之间联系的看法，表观基因调控是自然科学中的一个新兴研究领域。

Bone marrow of humans and other animals contains stem cells that can become each of the various cell types of the immune system. This process, called differentiation, creates specific types of immune cells and requires changes in gene expression that are initiated by cell signaling events. Genes important for the flexible nature of the stem cell are turned off, while genes important to the mature immune cell are activated. These changes in gene expression involve stable structural changes to chromatin or DNA in a process called epigenetic gene regulation. Specific genes are turned off by packaging them very tightly so that they are inaccessible within the chromatin, while others are turned on by packaging more loosely to ease access. The processes of histone acetylation and DNA methylation are major contributors.******Mast cells are an immune cell type that plays important roles in defense, but we do not fully understand how they differentiate from stem cells. One type of signaling that we know is important for the differentiation of mast cells is the mitogen-activated protein kinase (MAPK) pathway. MAPK signaling is connected to epigenetic changes during the differentiation of other cell types and we know that it is activated and important for mast cell differentiation. While some epigenetic changes have been found in mast cell differentiation, the signaling that controls it is unknown. The link between these events represents a major gap in our understanding, and highlights the novelty of my proposed research. My research team has identified the activation of several epigenetic enzymes in differentiating mast cells. We hypothesize that MAPK signals contribute to activation of epigenetic enzymes which cause mast cell genes to be turned on and stem cell genes to be turned off during differentiation. ******To determine the role of the MAPK signaling in mast cell differentiation epigenetics, we will conduct experiments to meet the following 3 objectives: ***1) Determine the importance of MAPK signaling in histone acetylation during mast cell differentiation. ***2) Assess the role of MAPK signaling in DNA methylation during mast cell differentiation. ***3) Examine the significance of MAPK proteins entering the nucleus during mast cell differentiation and activation. ******Expected significance: The overall objective of the proposed research is to improve our understanding of how MAPK proteins regulate gene expression within the nucleus during mast cell differentiation. MAPK signaling is highly conserved and important in a wide variety cell functions, including growth, differentiation, development, response to stress, and cell death. Given this breadth of functional roles, the results obtained could have broad biological applications. This work will enhance our perspective on the connections between cell signaling mechanisms and epigenetic gene regulation, an emerging area of research in the natural sciences.