Stress and Human Stem/Progenitor Cells: Biobehavioral Mechanisms

摘要 我们的目标是在人类中测试一个关于慢性压力和压力相关的生物行为过程对 干/祖细胞生物学。尽管在理解压力如何从生物学上变成 但关键的知识差距依然存在。生物学中的过程- 已经主要在形成组织和器官系统的分化细胞类型的水平上描述了DING。基于 考虑到压力的长期影响可以远远超过大多数分化的生命周期， 细胞，其补充不是从已经分化的“亲本”细胞发生，而是从干/祖细胞发生 细胞，我们提出的假设，生物嵌入的慢性压力的影响可能会一直延伸到干细胞的水平 细胞，以确定其生物学的基本方面，确定常见的压力和年龄相关疾病的最早脆弱性。 我们强调研究胎儿（新生儿）干细胞的重要性，特别关注造血干细胞（HSC）， 间充质干/祖细胞（MSC），并对他们的端粒和线粒体系统的功能能力，作为我们的 主要成果。我们使用母体非稳态负荷的复合生物学测量来操作慢性压力， 整合了妊娠应激传递途径的主要生物标志物。因为压力反应能力是 作为慢性应激效应的调节剂，我们还建议通过一种新的方法来表征HSC和MSC中的这种表型。 体外氧化应激[H2 O2]激发。我们将在N=300对母子中进行拟定研究;分离 分别从脐带血和脐带组织中培养新生HSCs和MSCs， 端粒酶活性和高分辨率呼吸测量实验表征端粒和线粒体功能 容量目的1将检验慢性应激暴露（非稳态负荷）与功能降低相关的假设。 新生儿HSC和MSC端粒和线粒体系统的容量。目标2A将检验慢性应激暴露 启动新生HSC和MSC的应激反应表型，Aim 2B将决定抗氧化剂（白藜芦醇） 预处理减弱了这种效应。这两个目标将包括测试性别和端粒的关键协变量的效应修饰， 线粒体功能目标3将阐明母亲的社会人口学、心理社会、行为和生物物理决定因素 使用最先进的机器学习，研究影响新生HSC/MSC生物学的非稳态负荷组分的变化， 预测方法。目标4将建立HSC、MSC、脐带血、脐带血和胎盘的共享生物库储存库 组织样本，用于未来的分子机制研究（基因表达，表观遗传学概况）和体外生物学研究， 是的。意义和影响：我们的项目将1）定义人类新生儿的新措施（及其规范） 干细胞，概况细胞健康和年龄相关疾病的风险最早的脆弱性; 2）扩大下， 新的细胞靶点和应激生物学嵌入的分子机制，反过来， 可以为个性化干预措施的发展提供信息;以及3）提供共享资源（人类新生儿干细胞） 细胞、胎盘、脐带和脐带血生物库）。

ABSTRACT Our goal is to test a novel hypothesis in humans about the impact of chronic stress and stress-related biobehavioral processes on stem/progenitor cell biology. Although substantial progress has been made in understanding how stress becomes biologically embedded to produce long-term effects, crucial knowledge gaps remain. The processes implicated in biological embed- ding have been described primarily at the level of differentiated cells types that form tissues and organ systems. Based on the consideration that the long-term effects of stress can extend well beyond the lifespan of most differentiated cells, whose replenishment does not occur from already-differentiated ‘parent’ cells, but occurs from stem/progenitor cells, we advance the hypothesis that biological embedding of the effects of chronic stress may extend all the way down to the level of stem cells, to define fundamental aspects of their biology that determine the earliest vulnerabilities for common stress- and age-related disorders. We underscore the importance of studying fetal (newborn) stem cells, focus specifically on hematopoietic (HSCs) and mesenchymal stem/progenitor cells (MSCs), and on the functional capacity of their telomere and mitochondrial systems as our primary outcomes. We operationalize chronic stress using a composite biological measure of maternal allostatic load that incorporates the principal biomarkers of the gestational stress transmission pathway. Because stress responsivity is a key modulator of chronic stress effects, we additionally propose to characterize this phenotype in HSCs and MSCs via an in vitro oxidative stress [H2O2] challenge. We will conduct the proposed study in N=300 mother-child dyads; isolate and culture newborn HSCs and MSCs from umbilical cord blood and cord tissue, respectively; and perform cellular telomerase activity and high-resolution respirometry experiments to characterize telomere and mitochondrial functional capacity. Aim 1 will test the hypothesis that chronic stress exposure (allostatic load) is prospectively associated with reduced functional capacity of newborn HSC and MSC telomere and mitochondrial systems. Aim 2A will test the hypothesis that chronic stress exposure primes the stress responsivity phenotype of newborn HSCs and MSCs, and Aim 2B will determine whether antioxidant (resveratrol) pretreatment attenuates this effect. Both aims will include tests for effect modification by sex and key covariates of telomere and mitochondrial function. Aim 3 will elucidate the maternal sociodemographic, psychosocial, behavioral and biophysical determinants of variation in components of allostatic load that impact newborn HSC/MSC biology using state-of-the-art machine learning and prediction approaches. Aim 4 will establish a shared Biobank repository of HSC, MSC, cord blood, cord and placental tissue samples for future studies of molecular mechanisms (gene expression, epigenetic profiles) and in vitro differen- tiation. Significance and Impact: Our project will 1) define novel measures (and their norms) in human newborn stem cells that profile the earliest vulnerabilities for cell health and risk of age-related disorders; 2) broaden under- standing of novel cellular targets and molecular mechanisms underlying biological embedding of stress, that, in turn, may inform the development of personalized interventions; and 3) provide shared resources (human newborn stem cell, placenta, cord, and cord blood biobank).