Liver SVCT Systems: Vitamin C Uptake, Roles & Regulation

这项建议旨在推动首席调查员(PI)实现他的学术目标 独立。为了达到这个目标，他将学习高级分子生物学和老鼠遗传学。 在他对肝脏中维生素C调节的研究中，他在技术以及肝脏病理/组织学方面进行了研究。抗坏血酸 (维生素C)是人体必需的微量营养素和有效的抗氧化剂。该基因的两种亚型 钠依赖的维生素C转运体(SVCT1和SVCT2)在许多人和小鼠中表达 组织，包括肝脏。关于SVCT的规定或相对贡献，我们一无所知 肝脏对整个维生素C摄取过程的调节。了解这些机制是 临床上相关，因为许多肝脏相关疾病受益于优化维生素C体内的动态平衡。我们的 研究将使用体外和体内两种方法对人类进行全面的检查 肝脏维生素C摄取过程及调控。我们将确定维生素C的特性/动力学 摄取，表征hSVCTI和hSVCT2启动子，确定hSVCTI和hSVCTI的相对贡献 HSVCT2使用siRNA方法进行总摄取，并进行关于适应性的影响的研究 维生素C摄取过程的调节，都是在人的肝细胞中。此外，我们还将确定 体内小鼠肝脏摄取维生素C的特征/动力学 为了合成维生素C，确定mSVCTI和mSVCT2对总摄取的相对贡献 使用cre/lox系统独立生成每个基因的肝脏特异性敲除，并继续我们的 在这一体内模型中研究维生素C摄取的适应性调节。我们对这些机制的研究 参与维持和调节正常的维生素C体内稳态将有可能使临床医生 在营养不足的情况下，为患者制定有效的策略。广泛的培训和 教育机会将使PI开始作为独立学术研究人员的职业生涯。

This proposal has been designed to advance the Principle Investigator (PI)towards his goal of academic independence. To attain that objective he will learn advanced molecular biology and mouse genetic techniques as well as liver pathology/histology in his studies of vitamin C regulation in the liver. Ascorbic acid (vitamin C) is a required essential micronutrient and effective antioxidant in humans. Two isoforms of the sodium-dependent vitamin C transporters (SVCT1 and SVCT2) are expressed in many human and mouse tissues, including the liver. Nothing is known regarding the regulation or relative contribution of the SVCT systems toward the overall vitamin C uptake process in the liver. Understanding these mechanisms is clinically relevant since many liver related diseases benefit from optimizing vitamin C body homeostasis. Our studies will use both an in vitro and in vivo approach to perform a comprehensive examination of the human liver vitamin C uptake process and regulation. We will determine the characteristics/kinetics of vitamin C uptake, characterize the hSVCTI and hSVCT2promoters, establish the relative contribution of hSVCTI and hSVCT2 towardtotal uptake using an siRNA approach and perform studies regardingthe effects of adaptive regulation of the vitamin C uptake process, all in human liver cells. In addition we will determine the characteristics/kinetics of vitamin C uptake in the liver of an in vivo mouse model that like humans is unable to synthesize vitamin C, establish the relative contribution of mSVCTI and mSVCT2 toward total uptake using the cre/lox system to generate liver specific knockouts of each gene independently, and continue our studies into adaptive regulation of vitamin C uptake in this in vivo model. Our studies into the mechanisms involved in maintaining and regulating normal vitamin C body homeostasis will potentially allow clinicians to develop effective strategies for patients during conditions of deficiency. The extensive training and educational opportunities will allow the PI to launch into a career as an independent academic researcher.