SICKLE RBC, INTERMITTENT HYPOXIA AND VASCULAR PATHOLOGY

镰状红细胞、间歇性缺氧和血管病理学

• 批准号: 6391217
• 负责人: Frans A. Kuypers
• 金额: $ 27.07万
• 依托单位: CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-30 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6391217
• 关键词: actin binding protein; blood vessel occlusion; cell cell interaction; cellular pathology; clinical research; disease /disorder model; enzyme activity; enzyme linked immunosorbent assay; erythrocyte membrane; erythrocytes; gelsolin; hemoglobin As; hemoglobin F; hemoglobin Ss; human subject; hypoxia; laboratory mouse; lysolecithins; nitric oxide; phospholipase A2; sickle cell anemia; superoxides; vascular endothelium

The unique oxygen sensing capacity of the sickle red cell defines sickle cell disease (SCD) pathology resulting from the polymerization of sickle hemoglobin under low partial oxygen pressure (PO2). Our long term goal is to understand how intermittent hypoxia changes the red cell membrane and its interactions with vascular endothelium (E.C.). We hypothesize a novel chain of events in which intermittent hypoxia will generate lysophosphatidic acid (LPA), a powerful lipid mediator, exposes phosphatidyl serine (PS) on the red surface, and depletes plasma gelsolin levels, the buffer protein for LPA. We pose that nitric oxide (NO) and related compounds, generated by E.C. under hypoxia will affect this process depending on the hemoglobin concentration and type (HbS, or HbF). Increased levels of the inflammatory mediator secretory phospholipase A2 (sPLA2) in SCD will further exacerbate this process which will ultimately lead to vascular drainage. To address these aspects of RBC-E.C. interaction, we have developed the following specific aims: I. To investigate the effect of intermittent hypoxia on sickle red cells. II. To investigate intermittent hypoxia on red cell-endothelial interaction, and III. To evaluate factors of intermittent hypoxia in sickle cell patients and murine models of sickle cell disease. To accomplish these goals, we will use a multidisciplinary approach using biochemistry and cell biology techniques to study RBC and E.C. under well-defined conditions of intermittent hypoxia in vitro, in a unique incubation system, separately or together. We will measure the generation of LPA in vitro and define its role, determine the LPA buffering capacity of the plasma actin-binding protein gelsolin, and define the role for E.C. derived NO and its derivatives. We will relate the data of in vitro studies to in vivo findings of LPA, gelsolin and NO footprints in SCD patients with vasoocclusive crisis, stroke and acute chest syndrome as well as our murine model for SCD. Together, our results may indicate novel treatment regiments in the management of SCD.

镰状细胞的独特氧气感应能力定义了镰状细胞病（SCD）病理学是由于在低部分氧气下（PO2）下镰状血红蛋白的聚合引起的。我们的长期目标是了解间歇性缺氧如何改变红细胞膜及其与血管内皮（E.C.）的相互作用。我们假设一系列新的事件链，其中间歇性缺氧将产生一种强大的脂质介质（LPA），它会在红色表面暴露于磷脂酰丝氨酸（PS），并消耗血浆凝胶蛋白水平，LPA的缓冲蛋白。我们构成了由E.C.在缺氧下产生的一氧化氮（NO）和相关化合物，将根据血红蛋白浓度和类型（HBS或HBF）影响这一过程。 SCD中炎症介质分泌磷脂酶A2（SPLA2）的水平增加将进一步加剧这一过程，最终导致血管排水。解决RBC-E.C的这些方面。相互作用，我们开发了以下特定目的：I。研究间歇性缺氧对镰状红细胞的影响。 ii。研究红细胞 - 内皮相互作用的间歇性缺氧和III。评估镰状细胞患者和镰状细胞疾病的鼠模型中间歇性缺氧因素。为了实现这些目标，我们将使用生物化学和细胞生物学技术采用多学科方法来研究RBC和E.C.在分别孵育系统中分别或一起在体外定义明确的缺氧条件下，分别或一起研究。我们将在体外测量LPA的产生，并确定其作用，确定血浆肌动蛋白结合蛋白凝胶蛋白的LPA缓冲能力，并定义E.C.衍生的NO及其衍生物的作用。我们将将体外研究的数据与LPA，凝胶林的体内发现以及血管胶合性危机，中风和急性胸部综合征以及SCD的鼠模型中的SCD患者的体内发现。总之，我们的结果可能表明SCD管理中的新型治疗方案。