A novel hydrogel-based instructive biohybrid 3D culture system for modeling human neural stem cell plasticity, neurogenesis, neurodevelopment, and neurodegeneration. Homo sapiens

Meaningful models of human neural development and neurodegeneration are extremely important when exploring stem-cell-based regenerative therapies. However, existing 3D cultures fall short of being highly defined, modular, and controllable. Adapting a glycosaminoglycan-based, cell-responsive hydrogel platform, we stimulated primary and induced human neural stem cells (NSCs) to manifest neurogenic plasticity and form extensive neuronal networks in vitro. The 3D cultures exhibited neurotransmitter responsiveness, electrophysiological activity, and tissue-specific extracellular matrix (ECM) deposition. By whole transcriptome sequencing, we identified that 3D cultures express mature neuronal markers, and reflect the in vivo genetic program of mature cortical neurons compared to 2D cultures. Thus, our data suggest that our established 3D hydrogel culture supports the tissue-mimetic maturation of human neurons in an unprecedented manner. We modeled neurodegenerative conditions by treating the cultures with A?42 peptide and observed the known human pathological effects of Alzheimer?s disease including reduced NSC proliferation, impaired neuronal network formation, synaptic loss and failure in ECM deposition as well as elevated Tau hyperphosphorylation and formation of neurofibrillary tangles. We also determined the changes in transcriptomes of primary and induced NSC-derived neurons after A?42, providing a useful resource for further studies. Thus, our hydrogel-based human cortical 3D cell culture is a powerful platform for studying various aspects of neural development and neurodegeneration, as exemplified for A?42 toxicity and neurogenic stem cell plasticity. Overall design: Primary (from Gestation week 21 of human fetus) and induced (adult human fibroblast-derived) neural stem cells are cultured in 2D and 3D. Next generation sequencing is performed at 3 weeks of culture.