Roles of Ascl1 for generation and differentiation of taste cells

Ascl1 在味觉细胞生成和分化中的作用

• 批准号: 9157278
• 负责人: ICHIRO MATSUMOTO
• 金额: $ 32.51万
• 依托单位: MONELL CHEMICAL SENSES CENTER
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9157278
• 关键词: Adult; Affect; Aging; Alleles; Animals; Apoptosis; Automobile Driving; Basal Cell; Birth; Cell Lineage; Cell Maintenance; Cells; Characteristics; Code; Communication; Complementary DNA; Complex; Diet Habits; Embryonic Development; Ensure; Gene Expression; Generations; Genes; Goals; Healthy Eating; Homeodomain Proteins; Homeostasis; Homologous Gene; Human; Immunohistochemistry; In Situ Hybridization; Infection; Knock-out; Knockout Mice; Knowledge; Lateral; Lead; Life; Longevity; LoxP-flanked allele; Maintenance; Mediating; Mitotic; Molecular; Mus; Nerve; Neuroglia; Neurons; Play; Property; Proteins; Quality of life; RNA; Radiation therapy; Research; Research Design; Role; Savory; Site; Sodium Chloride; Staging; Stem cells; Structure; Supporting Cell; Taste Bud Cell; Taste Buds; Taste Disorders; Taste Perception; Testing; Type I Epithelial Receptor Cell; Type II Epithelial Receptor Cell; Type III Epithelial Receptor Cell; Undifferentiated; Vertebrates; Work; cell type; chemotherapy; improved; neurogenesis; oral cavity epithelium; precursor cell; progenitor; protein expression; recombinase; relating to nervous system; research study; response; selective expression; stem; taste stimuli; taste system; taste transduction; transcription factor

Summary Taste contributes to quality of life, as well as to healthy eating habits. In humans and other vertebrate animals, taste transduction occurs in taste buds, when taste stimuli interact with mature (terminally differentiated) specialized cells that are often classified as type I, II, and III cells. Normal continuous turnover of taste cells underlies the homeostasis of taste; when turnover is disrupted, taste is likewise disrupted. Taste cells are derived from stem/progenitor cells, which continuously supply new taste cells throughout an animal's life. However, the mechanisms of taste cell turnover are poorly understood. Our recent studies have revealed that the Pou2f3 transcription factor is necessary for type II cell generation, and that the generation of type II cells, which mediate sweet, umami (savory), and bitter tastes, is intimately related with that of type III cells, which mediate sour and salty tastes and may be involved in intercellular lateral communication between type II and III cells. Our preliminary findings indicate that Ascl1, a transcription factor expressed in basal precursor and differentiated type III cells within taste buds, is involved in the generation of type III cells and probably type II cells in part during embryonic development in mice. We therefore propose to elucidate the roles of Ascl1 in molecular and cellular mechanisms in the generation and functional differentiation/maintenance of type III cells during taste cell turnover in adult mice. We will also examine Ascl1's role in the generation of type II cells. Because conventional Ascl1 knockout mice die shortly after birth, we will use two types of Ascl1 conditional knockout (cKO) mice. These mice have a “floxed” Ascl1 allele that has loxP sites at 5' and 3' of an Ascl1 coding sequence, and Cre recombinase expressed in specific cell types and driving Cre-loxP mediated Ascl1 deletion in these cells. Because Ascl1 may play different roles in basal precursor and differentiated type III cells, we will conduct experiments of Aims 1 and 2 to distinguish between these roles. In Aim 1, we will induce Ascl1 cKO in differentiated type III cells. This experiment will test the hypothesis that Ascl1's expression in type III cells is necessary for functional differentiation/maintenance of these cells. In Aim 2, we will induce Ascl1 cKO in taste progenitor/stem cells that give rise to basal precursor cells. This experiment will test the hypothesis that Ascl1 is necessary for the generation of type III and II cells. In both Aims, we will analyze whether Ascl1 deficiency affects molecular and functional characteristics of specific types of taste cells, using on the taste system will be assessed in these two types of Ascl1 cKO mice with (a) histochemical gene and protein expression analyses to examine histochemical analyses and gustatory nerve recordings. Knowledge obtained from this research will improve understanding of taste cell turnover and the mechanisms of taste loss accompanying radio- and chemotherapy, infectious conditions, and aging.

概括 品味有助于生活质量以及健康饮食习惯。在人类和其他脊椎动物中， 当味道刺激与成熟（终端区分）相互作用时，味蕾发生在味蕾中 通常被归类为I型，II和III型细胞的专门细胞。味觉细胞的正常连续离职 是味觉稳态的基础；当营业额中断时，味道同样会破坏。味道是 源自茎/祖细胞，在动物的生活中不断提供新的味觉细胞。 但是，味觉细胞更新的机制知之甚少。我们最近的研究表明 POU2F3转录因子对于II型细胞的产生是必需的，而II型细胞的产生， 介导甜，鲜味（咸味）和苦味的甜味与III型细胞密切相关， 介导酸味和咸味，可能参与II和III型之间的细胞间侧向通信 细胞。我们的初步发现表明ASCL1是基本前体中表达的转录因子，并且 味蕾内的分化III型细胞参与III型细胞的产生，可能是II型 细胞部分在小鼠胚胎发育过程中。因此，我们建议阐明ASCL1在 III型细胞的生成和功能分化/维持中的分子和细胞机制 在成年小鼠的味道细胞更新期间。我们还将检查ASCL1在II型细胞的产生中的作用。 因为传统的ASCL1敲除小鼠出生后不久死亡，我们将使用两种类型的ASCL1条件 敲除（CKO）小鼠。这些鼠标具有“ flox” ASCL1等位基因，该等位基因在ASCL1的5'和3'中具有LOXP位点 在特定细胞类型中表达的编码序列和CRE重组酶，并驱动Cre-loxp介导的ASCL1 这些细胞中的缺失。因为ASCL1可能在基本前体和差异化III中扮演不同的角色 细胞，我们将进行目标1和2的实验，以区分这些角色。在AIM 1中，我们将诱导 分化型III细胞中的ASCL1 CKO。该实验将检验以下假设。 III型细胞对于这些细胞的功能分化/维护是必需的。在AIM 2中，我们将诱导 味道祖细胞/干细胞中的ASCL1 CKO产生基本的前体细胞。该实验将测试 假设ASCL1对于III型和II型细胞的产生是必需的。在这两个目标中，我们都将分析 ASCL1缺乏是否影响特定类型味道细胞的分子和功能特征，使用 在这两种类型的ASCL1 CKO小鼠中，将在味觉系统上进行（a）组织化学基因和 蛋白质表达分析以检查组织化学分析和味觉神经记录。知识 从这项研究获得的将提高对味觉细胞更新和味觉丧失机制的理解 参加放射和化学疗法，传染病和衰老。