Basic and Translational Research Program (BTRP) in Sickle Cell Disease

描述（由申请人提供）： 镰状细胞病（SCD）的挑战是点突变如何改变单个蛋白质中的单个氨基酸，导致具有多变表现的疾病。玛丽安安德森综合镰状细胞中心（MAC）在过去的研究中使用了生命的第一年，一个生理上的关键时期，以评估生物标志物足迹随着婴儿的成长。我们最近的研究表明，HbF不能保护HbSS患者免受2年内发生的内皮激活。然而，我们注意到这些生物标志物与溶血标志物如LDH相关。磷脂酰丝氨酸阳性（PS+）红细胞表现出渗透脆性，该循环队列与内皮活化之间存在相关性。儿童HbSS的临床证据证实了我们的结果，因为在年轻的HbSS患者中，无症状CNS梗死的发生率令人担忧。还发现PS+红细胞与颅内TCD异常相关（Styles et al），这表明PS+红细胞还与大血管疾病相关。这些研究使我们敏锐地意识到，调节溶血仍然是镰状细胞患者护理的最前沿。最近的临床试验令人沮丧，包括L-精氨酸，一种Gardos抑制剂，Mg Pidolate被副作用所困扰，一氧化氮（NO）吸入血管闭塞仍在评估中。我们的两个项目（中心间试验和转化）将评估溶血的新方法。首先，我们将使用NO的口服增强剂（亚硝酸盐和BH 4）通过提供长期的血管舒张作用来减少SCD中NO相关的内皮功能障碍。该转化项目将使用n-3脂肪酸补充剂通过保护红细胞膜来减少溶血。根据Serhan等人令人兴奋的工作，这项研究是新颖的，他们最近表明二十碳五烯酸和二十二碳六烯酸是有效的新化合物的前体，Protectins和Resolvins阻止炎症时钟，并抑制缺血再灌注损伤。这项工作的另一个基本原理是，这些脂肪酸已被证明是缺乏在HbSS疾病的血液循环细胞成分的膜。我们与Serhan博士建立了合作关系，他将在我们的翻译项目中评估他的小说调解人的水平。我们的基础科学项目利用溶血的主题，将这一挑战解构为血红素和微粒的主要成分（分别给予伯克小鼠和联合给予）。我们将专门评估两个新的领域，即促凝血表型（基于我们在体外证明血红素导致内皮TF表达）和粘附表型（我们的数据表明血红素上调内皮PS受体）。计划通过上游抑制剂调节溶血诱导的表型，还计划使用Protectins和Resolvins。病人服务项目是一个创新的建议，以开发和评估一个简短的家庭为基础的干预目标生活质量和学校功能在SCD。如果成功，其结果将有可能转移到镰刀护理组织作为标准病人服务计划的一部分。对MAC教育至关重要的是一个强大的临床核心的专门工作人员支持该中心不断增长的病人人数，其中包括成人和儿童在费城和路易斯维尔。该中心是一个病人服务中心，通过宾夕法尼亚州和肯塔基州的教育和社区推广，将我们最先进的研究和病人护理转化为实践。

DESCRIPTION (provided by applicant): The challenge of sickle cell disease (SCD) is how a point mutation, which changes a single amino acid in a single protein, causes a disease with protean manifestations. The Marian Anderson Comprehensive Sickle Cell Center (MAC) has in past studies used the first years of life, a physiologically crucial period, to evaluate the biologic biomarker footprint created as the infant grows. Our studies have recently demonstrated that HbF does not protect patients with HbSS against endothelial activation which occurs by 2 years of life. We note, however, that these biomarkers correlate with markers of hemolysis such as LDH. Phosphatidylserine-positive (PS+) erythrocytes demonstrate osmotic fragility, with correlates between this circulating cohort and endothelial activation. Clinical evidence in the child with HbSS confirms our results, since there is an alarming rate of silent CNS infarction in the young HbSS patient. PS+ red cells were also noted to correlate with abnormal intracranial TCDs (Styles et al), suggesting additionally a tie-in with large vessel disease. Such studies make us acutely aware that modulating hemolysis remains at the forefront of sickle cell patient care. Recent clinical trials have been disheartening including L-Arginine, a Gardos Inhibitor, Mg Pidolate is beset with side effects, and nitric oxide (NO) inhalation in vasocclusion is still under evaluation. Two of our projects (Inter-Center Trial and Translational) will evaluate novel approaches to hemolysis. In the first, we will use oral enhancers of NO (nitrite and BH4) to decrease NO-related endothelial dysfunction in SCD by providing a long term vasodilatory effect. The translational project will use n-3 fatty acid supplementation to reduce hemolysis by protecting the red cell membrane. This study is novel in light of exciting work by Serhan et al, who recently showed that Eicosapentaenoic and Docosahexaenoic acids are precursors of potent new classes of compounds, the Protectins and Resolvins that stop the clock on inflammation, and inhibit ischemia-reperfusion injury. An additional rationale for this work is that these fatty acids have been shown to be deficient in the membranes of the circulating cellular elements of blood in HbSS disease. We have forged a collaboration with Dr. Serhan who will assess levels of his novel mediators in our Translational Project. Our Basic Science Project capitalizes on the theme of hemolysis by deconstructing this challenge into its major components of heme and microparticles (given separately and in combination to Berk mice). We will specifically assess two new areas, i.e. procoagulant phenotype (based on our demonstration in vitro that heme causes endothelial TF expression), and an adhesive phenotype (our data demonstrates that heme upregulates an endothelial PS receptor). Modulation of hemolysis-induced phenotypes by upstream inhibitors is planned, and also the use of Protectins and Resolvins. The Patient Services Project is an innovative proposal to develop and evaluate a brief family-based intervention targeting QoL and school functioning in SCD. If successful, its results will be potentially transferable to sickle care organizations as part of standard patient services programs. Crucial to the MAC edifice is a robust clinical core of dedicated staff supporting the Center's growing patient population, which includes adults and children in Philadelphia and Louisville. Rounding out the Center is a patient services core translating our state of the art research and patient care into practice through education and community outreach in Pennsylvania and Kentucky.