Genetic variants of the mechanosensitive ion channel Piezo1 in red blood cells - their role in human physiology and evolution

红细胞中机械敏感离子通道 Piezo1 的遗传变异 - 它们在人类生理和进化中的作用

• 批准号: 522062907
• 负责人: Professor Dr. Lars Kaestner
• 金额: --
• 依托单位: Universitair Medisch Centrum Utrecht
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/522062907?language=en
• 关键词: Genetic; variants; mechanosensitive; ion; channel

This project aims to establish the possible links between erythroid Piezo1 polymorphisms and channel activity, deformability, oxygen carrying capacity of red blood cells (RBC), and finally tissue oxygenation. Reaching this aim will support or disapprove the hypothesis of the possible role of Piezo1 variants in adaptation to the changing environmental conditions and natural selection in modern humans (mh). To test our hypothesis, we aim to perform genome editing of human-induced pluripotent stem cells (iPSC) carrying the mh_Piezo1 sequence (coding 307G) and replace it with the archaic arc_Piezo1 variant (coding 307S). Ex vivo amplification of RBC from modified iPSC (arc_RBC) will allow us to investigate the electrophysiological arc_Piezo1 channel properties and its impact on erythropoiesis and, finally, RBC function in comparison to the unmodified RBC (mh_RBC). Furthermore, in vivo effects on RBC properties, oxygen delivery, and tissue oxygenation caused by Piezo1 alterations will be investigated systemically in a mouse model with genetically or pharmacologically modified Piezo1 activity. We will use a gain of function (GOF) mouse model. To get initial insight into the role of Piezo1 variants in human tissue oxygenation, Piezo1 channel function and RBC properties as well as tissue oxygenation measurements after physical exercise will be performed in a small cohorts of Hereditary Xerocytosis (HX) patients carrying known Piezo1 GOF mutations. We do not aim to investigate the pathophysiology of HX, but we will take advantage of the pathological Piezo1 mutations and their effect on tissue oxygenation under stress conditions in vivo. Comparable experiments will be performed in a matched group of healthy controls. Finally, mathematical modelling of potential environmental determinants and associated selective processes is a viable approach to distinguish demographic from selective effects, in our case, to elucidate the demographic landscape and history of Piezo1 polymorphisms affecting RBC physiology (channel function, Calcium signalling, cell flow properties, and oxygen delivery capacity). Various methods have been proposed for estimations from binary or ordinal genotypic/phenotypic data from a limited number of individuals, including Approximate Bayesian Computation (ABC) methods. We will use the latter to test our two hypotheses by simulating the effects of potential selection mechanisms based on our experimental results.

该项目旨在建立红细胞Piezo 1多态性与红细胞（RBC）的通道活性、变形性、携氧能力以及最终组织氧合之间的可能联系。实现这一目标将支持或不赞成Piezo 1变体在适应现代人类（mh）不断变化的环境条件和自然选择中可能发挥作用的假设。为了验证我们的假设，我们的目标是对携带mh_Piezo1序列（编码307 G）的人类诱导多能干细胞（iPSC）进行基因组编辑，并将其替换为古老的arc_Piezo1变体（编码307 S）。来自修饰iPSC（arc_RBC）的RBC的离体扩增将使我们能够研究电生理arc_Piezo1通道特性及其对红细胞生成的影响，最后与未修饰RBC（mh_RBC）相比研究RBC功能。此外，将在具有遗传或非遗传修饰的Piezo 1活性的小鼠模型中系统地研究Piezo 1改变对RBC性质、氧递送和组织氧合的体内影响。我们将使用功能增益（GOF）小鼠模型。为了初步了解Piezo 1变体在人体组织氧合中的作用，将在一小群携带已知Piezo 1 GOF突变的遗传性干细胞症（HX）患者中进行Piezo 1通道功能和RBC特性以及体育锻炼后的组织氧合测量。我们的目的不是研究HX的病理生理学，但我们将利用病理性Piezo 1突变及其在体内应激条件下对组织氧合的影响。将在匹配的健康对照组中进行可比实验。最后，潜在的环境决定因素和相关的选择性过程的数学建模是一个可行的方法来区分人口选择性的影响，在我们的情况下，阐明人口景观和历史的Piezo 1多态性影响红细胞生理（通道功能，钙信号，细胞流动特性和氧输送能力）。已经提出了各种方法用于从有限数量的个体的二进制或有序基因型/表型数据进行估计，包括近似贝叶斯计算（ABC）方法。我们将使用后者来测试我们的两个假设，根据我们的实验结果模拟潜在选择机制的影响。