Oligosaccharides Regulating Cell Function

描述（由申请人提供）：细胞凋亡是一种高度调节的细胞死亡过程。细胞凋亡在分子水平上的失调与包括癌症在内的多种人类疾病有关。低分子量果胶（LMP）是一种来源于植物细胞壁的复合碳水化合物，已显示可诱导癌细胞凋亡，导致小鼠肿瘤体积缩小。然而，由于LMP的复杂结构和样品异质性，解释这种观察到的细胞凋亡的机制的结构-功能关系仍然难以捉摸。因此，通过将酶和灵敏的分析技术与为表征肝素/硫酸乙酰肝素样糖胺而开发的生物测定相结合的策略进行扩展， 由于LMP是聚糖，本授权申请中提出的实验旨在产生更明确的、具有生物活性的LMP衍生物。 这些LMP寡糖将有助于澄清LMP的具体结构，负责多糖的骨化诱导作用。在我们初步实验结果的基础上，该资助申请的具体目标有两个：具体目标I将专注于通过开发LMP降解和反应产物筛选所需的必要酶和分析工具，扩展我们实验室为糖胺聚糖表征开发的方法。Specific Aim II将第一个特定目标中开发的酶和分析工具整合到一个系统方案中，用于生成和纯化保留诱导细胞凋亡能力的定义的LMP衍生物。 总的来说，本资助申请中概述的研究将产生分子量较低、结构异质性较小的LMP衍生寡糖，这些寡糖是进一步表征诱导细胞凋亡的细胞作用机制所需的。该资助申请代表了一项高风险/高回报的事业，旨在开发LMP作为由细胞凋亡失调引起的衰弱性疾病（如癌症）的有效治疗。

DESCRIPTION (provided by applicant): Apoptosis is a highly regulated process of cell death. De-regulation of apoptosis at the molecular level has been implicated in a variety of human diseases, including cancer. Low molecular weight pectin (LMP), a complex carbohydrate derived from the wall of plant cells, has been shown to induce apoptosis in cancer cells leading to a reduction in tumor volume in mice. However, due to the complex structure and sample heterogeneity of LMP, a structure-function relationship to explain the mechanism underlying this observed apoptosis has remained elusive. Therefore, by extending the strategy of combining enzymes and sensitive analytical techniques with biological assays developed for the characterization of heparin/heparan sulfate-like glycosamino- glycans, the experiments proposed in this grant application are designed to produce more defined, biologically active LMP-derivatives. These LMP oligosaccharides will help provide clarity on the specific structure of LMP responsible for the polysaccharide's apoptosis-inducing effect. Building on the results of our initial experiments, the specific aims of this grant application are twofold: Specific Aim I will focus on expanding the methodology developed by our laboratory for the characterization glycosaminoglycans by developing the necessary enzymatic and analytical tools required for the degradation of LMP and the screening of the reaction products. Specific Aim II integrates the enzymatic and analytical tools developed in the first specific aim into a systematic protocol for the generation and purification of defined LMP derivatives that retain the ability to induce apoptosis in cells. As a whole, the research outlined in this grant application will yield LMP-derived oligosaccharides with lower molecular weight and less structural heterogeneity that are required for the further characterization of the cellular mechanism of action responsible for the induction of apoptosis. This grant application represents a high risk/high reward undertaking aimed at developing LMP as an effective treatment for of debilitating diseases caused by the deregulation of apoptosis, such as cancer.