Extracellular vesicle cargo and risk of NAFLD and NASH in Latino youth

项目总结/摘要 儿童非酒精性脂肪性肝病（NAFLD）的患病率在美国青年中不断上升，特别是在 拉丁美洲血统。儿童NAFLD与不良的长期结局相关，包括糖尿病， 心血管疾病，以及成年期较高的肝脏相关发病率和死亡率。尽管临床 尽管儿童NAFLD的发病机制尚未阐明，但其发病机制仍不清楚。这种缺乏 缺乏知识是制定有效治疗和预防战略的主要障碍。新兴 研究支持细胞外囊泡（EV）在NAFLD中的作用。循环EV可以影响细胞内 信号传导、组织损伤和修复以及肝细胞中的基质重塑。血浆EV水平可区分 NAFLD和非酒精性脂肪性肝炎（NASH）的成人患者，并且与 组织学分级我们进行了一系列的原理验证研究，证明：1）独特的蛋白质 从患有NAFLD的拉丁裔儿童中分离的血浆EV中的特征，2）NAFLD特异性特征近似 在减少肝脏脂肪的生活方式干预后的非NAFLD特征，和3）分离肝细胞- 特异性EV显示NAFLD中肝脏特异性蛋白质的富集。然而，迄今为止， 儿童NAFLD的发病率很低，并且EV衍生的货物在青年NAFLD发病机制中的作用仍然未知。 在这里，我们提出了一个策略来表征EV在儿科NAFLD中的生物学作用。在目标1中，我们将应用 无偏见的方法来研究循环和肝细胞富集EV中携带的蛋白质和RNA， 与拉丁美洲青年NAFLD和NASH相关的特征性特征。在目标2中，我们将测量EV 在两次治疗后经历肝脂肪分数变化的NAFLD青年中， 不同的干预模式（即，密集的生活方式和减肥手术）。重要的是，在目标3中，我们提出了一个 一系列的分子实验，以获得电动汽车货物的功能方面的机制洞察。的 这些方法的组合是创新的;该战略包括一个新的和顺序适当的 一组以前未用于解决儿科疾病发病机制的目标 NAFLD。对儿童的关注特别有影响，因为NAFLD在这一人群中的患病率越来越高， 儿童NAFLD与成人健康状况不良的相关性，以及预期的未来经济 照顾这些人的负担。关注拉丁裔儿童作为一个代表性不足，但不断增长的人口 人口统计是至关重要的，因为在生命的每一个阶段和沿着整个NAFLD谱，拉丁美洲人的经验， 不成比例的疾病负担与儿童NAFLD相关的EV衍生货物的鉴定 将增强我们对疾病发病机制的生物学机制的理解， 改善诊断和治疗策略，并确定潜在药物开发的新靶点。

PROJECT SUMMARY/ABSTRACT The prevalence of pediatric nonalcoholic fatty liver disease (NAFLD) is escalating in US youth, particularly in those of Latino ancestry. NAFLD in children is associated with poor long-term outcomes, including diabetes, cardiovascular disease, and higher liver-related morbidity and mortality in adulthood. Despite the clinical significance of pediatric NAFLD, the mechanisms underlying its pathogenesis are poorly understood. This lack of knowledge is a major obstacle to the development of effective treatment and prevention strategies. Emerging studies support a role for extracellular vesicles (EVs) in NAFLD. Circulating EVs can influence intracellular signaling, tissue injury and repair, and matrix remodeling in liver cells. Plasma EV levels discriminate between adult patients with NAFLD and nonalcoholic steatohepatitis (NASH), and are positively correlated with histological grade. We conducted a series of proof-of-principle studies that demonstrate: 1) distinctive protein signatures in plasma EVs isolated from Latino children with NAFLD, 2) NAFLD-specific signatures approximate non-NAFLD signatures following lifestyle intervention that reduced liver fat, and 3) isolation of hepatocyte- specific EVs showed enrichment of liver-specific proteins in NAFLD. To date, however, investigations of EVs in pediatric NAFLD are scarce, and the role of EV-derived cargo in NAFLD pathogenesis in youth remains unknown. Here we propose a strategy to characterize the biological role of EVs in pediatric NAFLD. In Aim 1, we will apply unbiased methods to study proteins and RNAs carried in circulating and hepatocyte-enriched EVs to derive characteristic signatures associated with NAFLD and NASH in Latino youth. In Aim 2, we will measure EV concentration and content in youth with NAFLD who experienced changes in hepatic fat fraction following two distinct intervention modalities (i.e., intensive lifestyle and bariatric surgery). Importantly in Aim 3, we propose a series of molecular experiments to obtain mechanistic insight into the functional aspects of EV cargo. The combination of these approaches is innovative; and the strategy comprises a novel and sequentially appropriate set of aims that has not previously been used to address potential mechanisms of pathogenesis in pediatric NAFLD. The focus on children is especially impactful due to the growing prevalence of NAFLD in this population, the association of pediatric NAFLD with poor health outcomes in adulthood, and the expected future economic burden to care for these individuals. The focus on Latino children as an underrepresented yet growing population demographic is critical, because at every stage of life and along the entire NAFLD spectrum, Latinos experience a disproportionate burden of disease. The identification of EV-derived cargo associated with pediatric NAFLD will enhance our understanding of the biological mechanisms contributing to disease pathogenesis, provide a means to improve diagnostic and therapeutic strategies, and identify new targets for potential drug development.