Cystein, Intestinal Thiols and Goblet Cell Development

半胱氨酸、肠硫醇和杯状细胞发育

• 批准号: 7087054
• 负责人: Rex Gaskins
• 金额: $ 25.19万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7087054
• 关键词: cell growth regulation; cysteine; diet route /schedule; gastrointestinal epithelium; gel mobility shift assay; gene expression; genetic transcription; glutathione; goblet cells; high performance liquid chromatography; inflammation; intestinal mucosa; intravenous administration; laser capture microdissection; microarray technology; miniature swine; nutrition related tag; oxidation reduction reaction; parenteral feedings; polymerase chain reaction; small intestines; terminal nick end labeling; thiols; thioredoxin; tissue /cell culture; western blottings

DESCRIPTION (provided by applicant): The proposal originates from our observations of a three to four fold increase in the number of acidomucin-positive goblet cells accompanied by glutathione (GSH) depletion in the small intestinal mucosa of neonatal pigs being nourished parenterally. We hypothesize that the lack of luminal cysteine is the primary insult perceived by the parenterally nourished epithelium, and that the functional endpoint of this nutritional deficiency is a more oxidized intracellular redox potential The identification of this amino acid as a key nutritional factor is based on (a) the high rate of first-pass consumption of dietary cysteine and the low rate of arterial cysteine utilization by the intestine; (b) evidence that cellular redox status is a key determinant of cellular differentiation, and (c) the fact that cysteine is structurally and functionally involved in both intracellular redox status and mucosal defense via its inherent contribution to the thiol buffers GSH and thioredoxin (Trx) on one hand, and the goblet cell-specific secretory mucins and intestinal trefoil factor (ITF) on the other. We hypothesize that parenteral nutrition results in a preferential activation of the mucous cell lineage as well as selective sparing of goblet cells leading to the repopulation (at a reduced rate) of the villus with goblet cells relative to absorptive enterocytes. The alteration in goblet cell development is initiated by hyperoxia that stems from compromised cysteine status. In other words, we hypothesize that goblet cells are the guardians of mucosal redox homeostasis. Our hypothesis will be tested in three specific aims: 1) Determine if a causal relationship exists between epithelial redox status and goblet cell expansion, independent of TPN-associated inflammation. 2) Quantify, in a goblet cell culture model system, the hierarchy of cysteine usage for the synthesis of GSH and Trx versus ITF and secretory mucins, as well as the role of the transsulfuration pathway in the formation of cysteine and sulfate from methionine, as affected by apical versus basal provision of cysteine, and in response to graded levels of hyperoxia. Simultaneously, determine if the source (inorganic vs. cysteine-derived) and flux of sulfate used for sulfomucin biosynthesis is affected by cysteine availability and hyperoxic stress. 3) Test the hypothesis that Cysl31 and/or Cys165, found within the activation domain of Cdx2, are redox sensitive and upon post-translational modification alter the specificity of Cdx2 transcriptional regulation.

描述（由申请人提供）：该提案源于我们观察到的观察到三到四倍的增加，酸性蛋白酸阳性的杯状细胞数量增加，伴随着新生儿猪的小肠粘膜中谷胱甘肽（GSH）的耗竭。我们假设缺乏腔腔半胱氨酸是育儿滋养的上皮所感知的主要侮辱性，并且这种营养不足的功能终点是一种更氧化的细胞内氧化还原的潜力，将这种氨基酸作为一个关键营养因子的识别是基于（a）的高率。肠； （b）证据表明细胞氧化还原状态是​​细胞分化的关键决定因素，并且（c）半胱氨酸在结构和功能上与细胞内氧化还原状态和粘膜防御都与硫醇缓冲剂GSH GSH和硫糖蛋白（TRX）的固有贡献有关，并且一方面是细胞细胞的特征菌素，以及其他分泌型（trx）的特征fiftery traffient（trx）。我们假设肠胃外营养会导致粘液细胞谱系的优先激活以及对圆锥细胞的选择性保留，从而导致绒毛（以降低的速率）与杯状细胞相对于吸收性肠细胞的绒毛。杯状细胞发育的变化是由源自半胱氨酸状态受损的高氧引发的。换句话说，我们假设杯状细胞是粘膜氧化还原稳态的监护人。我们的假设将以三个具体目的进行检验：1）确定上皮氧化还原状态与杯状细胞扩张之间是否存在因果关系，而与TPN相关的炎症无关。 2) Quantify, in a goblet cell culture model system, the hierarchy of cysteine usage for the synthesis of GSH and Trx versus ITF and secretory mucins, as well as the role of the transsulfuration pathway in the formation of cysteine and sulfate from methionine, as affected by apical versus basal provision of cysteine, and in response to graded levels of hyperoxia.同时，确定用于硫酸磺酸盐的生物合成的源（无机与半胱氨酸衍生的）和通量是否受半胱氨酸的可用性和高氧化应激的影响。 3）检验以下假设：在CDX2的激活结构域中发现的Cysl31和/或Cys165是氧化还原敏感的，并且在翻译后修饰时会改变CDX2转录调控的特异性。