Modeling early phenotypes of Parkinson’s disease by age-induced midbrain-striatum assembloids [RNA-Seq]. Modeling early phenotypes of Parkinson’s disease by age-induced midbrain-striatum assembloids [RNA-Seq]

Parkinson’s disease, an aging-associated neurodegenerative disorder, is characterised by nigrostriatal pathway dysfunction caused by the gradual loss of dopaminergic neurons in the substantia nigra pars compacta of the midbrain. Human in vitro models are enabling the study of the dopaminergic neurons’ loss, but not the dysregulation within the dopaminergic network in the nigrostriatal pathway. Additionally, these models do not incorporate aging characteristics which potentially contribute to the development of Parkinson’s disease. Here we present a nigrostriatal pathway model based on midbrain-striatum assembloids with inducible aging. We show that these assembloids can develop characteristics of the nigrostriatal connectivity, with catecholamine release from the midbrain to the striatum and synapse formation between midbrain and striatal neurons. Moreover, Progerin-overexpressing assembloids acquire aging traits that lead to early neurodegenerative phenotypes. This model shall help to reveal the contribution of aging as well as nigrostriatal connectivity to the onset and progression of Parkinson’s disease. Overall design: RNA sequencing analysis of assembloids generated from a healthy male cell line (WT) and its isogenic genetically engineered line with the progerin transgene (PROG), under the control of the TetOn system. Assembloids from both cell lines were either untreated (UNTR) or treated with doxycycline (DOX). Doxycycline is used to induce the expression of the progerin transgene in the PROG assembloids.

帕金森病（Parkinson’s disease）是一种与衰老相关的神经退行性疾病，其特征为中脑黑质致密部（substantia nigra pars compacta）多巴胺能神经元（dopaminergic neurons）逐渐丢失所致的黑质纹状体通路（nigrostriatal pathway）功能障碍。人类体外（in vitro）模型可用于研究多巴胺能神经元丢失，但无法探究黑质纹状体通路内多巴胺能网络的失调情况。此外，此类模型未纳入可能参与帕金森病发病的衰老相关特征。本研究报道了一种基于中脑-纹状体类组装体（midbrain-striatum assembloids）、具备可诱导衰老特性的黑质纹状体通路模型。研究证实，此类类组装体可形成黑质纹状体连接特征，实现中脑向纹状体释放儿茶酚胺（catecholamine），并可介导中脑神经元与纹状体神经元间的突触形成。此外，过表达早衰蛋白（Progerin）的类组装体可获得衰老相关特征，进而表现出早期神经退行性表型（phenotypes）。该模型将有助于揭示衰老与黑质纹状体连接异常在帕金森病发生与进展中的作用。实验整体设计：对由健康男性细胞系（野生型，WT）及其经TetOn系统（TetOn system）调控的携带有早衰蛋白转基因的同基因工程改造细胞系（PROG）所构建的类组装体，开展RNA测序（RNA sequencing）分析。两类细胞系来源的类组装体均分为两组：未处理组（UNTR）与多西环素（doxycycline）处理组（DOX），其中多西环素可诱导PROG组类组装体中早衰蛋白转基因的表达。