Hospital Israelita Albert Einstein, São Paulo, Brazil.
Institute of Chemistry, Universidade de São Paulo (USP), São Paulo, Brazil.
Parkinsonism Relat Disord. 2023 Nov;116:105847. doi: 10.1016/j.parkreldis.2023.105847. Epub 2023 Sep 15.
Progressive Supranuclear Palsy (PSP) is a neurodegenerative tauopathy and, to date, the pathophysiological mechanisms in PSP that lead to Tau hyperphosphorylation and neurodegeneration are not clear. In some brain areas, Tau pathology in glial cells appears to precede Tau aggregation in neurons. The development of a model using astrocyte cell lines derived from patients has the potential to identify molecules and pathways that contribute to early events of neurodegeneration. We developed a model of induced pluripotent stem cells (iPSC)-derived astrocytes to investigate the pathophysiology of PSP, particularly early events that might contribute to Tau hyperphosphorylation, applying omics approach to detect differentially expressed genes, metabolites, and proteins, including those from the secretome.
Skin fibroblasts from PSP patients (without MAPT mutations) and controls were reprogrammed to iPSCs, further differentiated into neuroprogenitor cells (NPCs) and astrocytes. In the 5th passage, astrocytes were harvested for total RNA sequencing. Intracellular and secreted proteins were processed for proteomics experiments. Metabolomics profiling was obtained from supernatants only.
We identified hundreds of differentially expressed genes. The main networks were related to cell cycle re-activation in PSP. Several proteins were found exclusively secreted by the PSP group. The cellular processes related to the cell cycle and mitotic proteins, TriC/CCT pathway, and redox signaling were enriched in the secretome of PSP. Moreover, we found distinct sets of metabolites between PSP and controls.
Our iPSC-derived astrocyte model can provide distinct molecular signatures for PSP patients and it is useful to elucidate the initial stages of PSP pathogenesis.
进行性核上性麻痹（PSP）是一种神经退行性tau 病，迄今为止，导致 PSP 中 Tau 过度磷酸化和神经退行性变的病理生理机制尚不清楚。在一些大脑区域，神经胶质细胞中的 Tau 病理学似乎先于神经元中的 Tau 聚集。使用源自患者的星形胶质细胞系开发模型有可能确定导致神经退行性变早期事件的分子和途径。我们开发了一种诱导多能干细胞（iPSC）衍生的星形胶质细胞模型，以研究 PSP 的病理生理学，特别是可能导致 Tau 过度磷酸化的早期事件，应用组学方法检测差异表达的基因、代谢物和蛋白质，包括来自分泌组的那些。
从 PSP 患者（无 MAPT 突变）和对照的皮肤成纤维细胞中进行重编程以获得 iPSC，进一步分化为神经祖细胞（NPC）和星形胶质细胞。在第 5 代时，收获星形胶质细胞用于进行全 RNA 测序。处理细胞内和分泌的蛋白质以进行蛋白质组学实验。仅从上清液获得代谢组学分析。
我们鉴定了数百个差异表达的基因。主要网络与 PSP 中的细胞周期重新激活有关。一些蛋白质仅由 PSP 组分泌。与细胞周期和有丝分裂蛋白、TriC/CCT 途径和氧化还原信号有关的细胞过程在 PSP 的分泌组中富集。此外，我们在 PSP 和对照组之间发现了不同的代谢物集。
我们的 iPSC 衍生星形胶质细胞模型可以为 PSP 患者提供独特的分子特征，有助于阐明 PSP 发病机制的初始阶段。
