Regulation of Heme Uptake and Transport in Caco-2 Cells

描述(由申请人提供)： 这项提案的总体目标包括一项计划，旨在促进Aliye UC博士的职业发展，同时进行肠道内血红素摄取和转运的研究。UC博士的长期职业目标是发展研究技能和经验，成为一名独立的临床科学家，能够为生物医学科学做出有意义的贡献。这一奖项将使她能够实现她的直接目标，通过课程学习在分子水平上加深她对血红素-肠道上皮细胞相互作用的理解，并获得细胞和分子生物学方面的新研究技能。这一奖项将使UC博士能够继续研究血红素与肠道上皮的相互作用，它对电解质运输的影响，以及氧化应激在调节这一功能中的可能作用。这一职业发展计划将在爱荷华大学进行，这是UC博士作为临床科学家发展的理想环境，布拉德利·E·布里蒂根博士将担任她的主要导师，约翰·B·斯托克斯博士担任共同导师。这种环境将为UC博士提供资源和充分获得关键专业知识的机会，这是在她的研究兴趣领域做出重大贡献所必需的。这项拟议的研究项目在一个成熟的肠上皮细胞模型Caco-2细胞中研究了参与血红素吸收和跨细胞运输的细胞机制。血红素提供了体内大部分的铁，但人们对其通过肠道的吸收知之甚少。它假设，血红素是通过一个也参与电解质运输的活跃过程，由肠上皮细胞获得并双向运输(从顶端到底端，反之亦然)。这一概念将通过追求以下具体目标来检验：1)确定参与肠上皮细胞血红素摄取的机制以及HO-1、细胞内血红素和铁水平在调节这一过程中的作用；2)确定涉及肠上皮细胞血红素跨细胞转运的机制以及HO-1、细胞内血红素和铁水平在调节这一过程中的作用；以及3)确定与血红素运输相关的电解质转运体(S)。这些研究将为理解血红素在正常和疾病状态(例如遗传性血色素沉着症、输血后继发的铁超载)通过肠道的运输提供新的见解，并探索肠上皮细胞双向血红素运动在铁储存调节中的作用。

DESCRIPTION (provided by applicant): The overall goal of this proposal includes a plan to foster the career development of Dr. Aliye Uc while undertaking the investigation of intestinal heme uptake and transport through the intestines. Dr. Uc's long term career goal is to develop the research skills and experience to become an independent clinician scientist, capable of making meaningful contribution to biomedical sciences. This award would allow her to fulfill her immediate goals for furthering her understanding of heme-intestinal epithelial cell interactions at a molecular level through course work and attaining new research skills in cellular and molecular biology. This award would enable Dr. Uc to continue her investigation on the interactions of heme with the intestinal epithelium, its effect on electrolyte transport and possible role of oxidative stress in modulating this function. This career development plan would take place at the University of Iowa, an ideal environment for Dr. Uc's development as a clinical scientist, with Dr. Bradley E. Britigan serving as her primary mentor and Dr. John B. Stokes acting as co-mentor. This environment will provide Dr. Uc both resources and full access to critical expertise, needed to make significant contribution in the area of her research interest. The proposed research project investigates the cellular mechanisms involved in absorption and transcellular transport of heme in a well-established intestinal epithelial cell model, Caco-2 cells. Heme provides the majority of body's iron, but little is known about its absorption through the intestines. It is hypothesized that heme is acquired and transported in both directions (apical to basolateral and vice versa) by the intestinal epithelial cells via an active process that is also involved in electrolyte transport. This concept will be tested by the pursuit of the following Specific Aims: 1) Determine the mechanisms involved in intestinal epithelial heme uptake and the role of HO-1, intracellular heme and iron levels in regulating this process; 2) Determine the mechanisms involved in transcellular intestinal epithelial cell heme transport and the role of HO-1, intracellular heme and iron levels in regulating this process; and 3) Determine the electrolyte transporter(s) associated with the transport of heme. These studies will provide new insight into understanding heme transport through intestines in normal and disease states (e.g., hereditary hemochromatosis, iron overload secondary to blood transfusions) and explore the role of intestinal epithelial cell bi-directional heme movement on the regulation of iron stores.