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

描述(申请人提供)：镰状细胞病(SCD)的挑战是点突变如何改变单一蛋白质中的单一氨基酸，导致具有多变表现的疾病。玛丽安·安德森综合镰刀细胞中心(MAC)在过去的研究中使用了生命的头几年，这是一个生理上的关键时期，来评估婴儿成长过程中产生的生物标志物足迹。我们最近的研究表明，HBF不能保护HbSS患者免受血管内皮细胞激活的影响，这种激活发生在生命2年后。然而，我们注意到这些生物标志物与溶血标志物如乳酸脱氢酶相关。磷脂酰丝氨酸阳性(PS+)红细胞表现出渗透脆性，这一循环队列与内皮激活有关。HbSS儿童的临床证据证实了我们的结果，因为在年轻的HbSS患者中，有一个令人震惊的无症状中枢神经系统梗死的比率。也注意到PS+红细胞与异常的颅内TCDs相关(Styles等人)，另外提示与大血管疾病有关。这样的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前沿。最近的临床试验令人沮丧，包括Gardos抑制剂L-精氨酸，匹多威镁副作用缠身，一氧化氮(NO)吸入治疗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BH4)通过提供长期的血管扩张作用来减少SCD中与NO相关的内皮功能障碍。该翻译项目将使用n-3脂肪酸补充剂，通过保护红细胞膜来减少溶血。鉴于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型化合物的前体，保护素和Resolvins可以阻止炎症时钟，并抑制缺血再灌注损伤。这项工作的另一个理由是，这些脂肪酸已经被证明在HbSS病的血液循环细胞元素的膜上是不足的。我们已经与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新调解人的水平。我们的基础科学项目利用溶血这一主题，将这一挑战解构为其主要成分血红素和微粒(单独和联合给予Berk小鼠)。我们将具体评估两个新的领域，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)和黏附表型(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以及保护素和Resolvins的使用来调节溶血诱导的表型。患者服务项目是一项创新的建议，旨在开发和评估针对SCD患者生活质量和学校功能的简短家庭干预措施。如果成功，其结果将有可能作为标准患者服务计划的一部分转移到镰刀护理组织。对MAC大楼至关重要的是一个强大的临床核心，由敬业的员工组成，为中心不断增长的患者群体提供支持，其中包括费城和路易斯维尔的成年人和儿童。该中心是一个患者服务核心，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患者护理转化为实践。

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.