Jiang Houbo, Xiao Zichun, Saleem Komal, Zhong Ping, Li Li, Chhetri Gaurav, Li Pei, Jiang Zhongjiao, Yan Zhen, Feng Jian
Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, NY, USA.
J Alzheimers Dis. 2025 Jun;105(4):1341-1354. doi: 10.1177/13872877251334831. Epub 2025 Apr 23.
BackgroundThe alternative splicing (AS) of , which encodes Tau, in the adult human brain produces six major isoforms that play critical roles in the pathogenesis of tauopathies including Alzheimer's disease. Previous efforts have failed to differentiate human induced pluripotent stem cells (hiPSCs) to cortical neurons expressing the six isoforms of Tau.ObjectiveWe aim to develop a differentiation method capable of producing the six Tau isoforms in hiPSC-derived cortical neurons.MethodsWe searched for the optimal concentration, duration and treatment window of morphogens in the differentiation of hiPSCs through embryoid bodies (EBs) to dorsal forebrain neuroepithelial cells then to cortical neurons.ResultsThe combined inhibition of WNT, SHH, and SMAD signaling in EBs generated neuroepithelial cells expressing appropriate dorsal forebrain markers, while suppressing ventral, midbrain, and hindbrain genes. Further differentiation in neurogenic and neurotrophic factors produced MAP2 neurons at day 18. The iPSC-derived neurons expressed markers of all cortical layers and exhibited synapse formation and synaptic physiology. In addition, MAP2 neurons and mitotic cells expressing radial glial markers formed aggregates that could be dissociated to produce mature neurons with similar properties. Most importantly, the six Tau isoforms were expressed from day 80 in a developmentally regulated manner, modeling the situation in human brains on an accelerated timeline.ConclusionsThis chemically defined differentiation method produces a key hallmark of mature human cortical neurons by expressing the six main splicing isoforms of Tau. It will greatly facilitate disease modeling and therapeutic discovery for many human brain disorders involving cortical neurons.
背景
编码Tau的基因在成人大脑中的可变剪接产生六种主要异构体，它们在包括阿尔茨海默病在内的tau蛋白病的发病机制中起关键作用。此前的研究未能将人类诱导多能干细胞（hiPSC）分化为表达Tau六种异构体的皮质神经元。
目的
我们旨在开发一种能够在hiPSC衍生的皮质神经元中产生六种Tau异构体的分化方法。
方法
我们通过胚胎体（EB）将hiPSC分化为背侧前脑神经上皮细胞，再分化为皮质神经元，寻找形态发生素的最佳浓度、持续时间和处理窗口。
结果
对EB中WNT、SHH和SMAD信号的联合抑制产生了表达适当背侧前脑标志物的神经上皮细胞，同时抑制了腹侧、中脑和后脑基因。在神经源性和神经营养因子中进一步分化，在第18天产生了微管相关蛋白2（MAP2）神经元。iPSC衍生的神经元表达所有皮质层的标志物，并表现出突触形成和突触生理学特性。此外，表达放射状胶质细胞标志物的MAP2神经元和有丝分裂细胞形成聚集体，可解离产生具有相似特性的成熟神经元。最重要的是，六种Tau异构体从第80天开始以发育调控的方式表达，在加速的时间轴上模拟了人类大脑中的情况。
结论
这种化学定义的分化方法通过表达Tau的六种主要剪接异构体，产生了成熟人类皮质神经元的一个关键标志。它将极大地促进许多涉及皮质神经元的人类脑部疾病的疾病建模和治疗发现。
