A Micropatterned Human‐Specific Neuroepithelial Tissue for Modeling Gene and Drug‐Induced Neurodevelopmental Defects

Abstract

The generation of structurally standardized human pluripotent stem cell (hPSC)‐derived neural embryonic tissues has the potential to model genetic and environmental mediators of early neurodevelopmental defects. Current neural patterning systems have so far focused on directing cell fate specification spatio‐temporally but not morphogenetic processes. Here, the formation of a structurally reproducible and highly‐organized neuroepithelium (NE) tissue is directed from hPSCs, which recapitulates morphogenetic cellular processes relevant to early neurulation. These include having a continuous, polarized epithelium and a distinct invagination‐like folding, where primitive ectodermal cells undergo E‐to‐N‐cadherin switching and apical constriction as they acquire a NE fate. This is accomplished by spatio‐temporal patterning of the mesoendoderm, which guides the development and self‐organization of the adjacent primitive ectoderm into the NE. It is uncovered that TGFβ signaling emanating from endodermal cells support tissue folding of the prospective NE. Evaluation of NE tissue structural dysmorphia, which is uniquely achievable in the model, enables the detection of apical constriction and cell adhesion dysfunctions in patient‐derived hPSCs as well as differentiating between different classes of neural tube defect‐inducing drugs.

Quantitative developmental biology in vitro using micropatterning

“…The development of neuruloids suggest that early ectodermal morphogenesis is an autonomous process, as non-ectodermal lineages are absent in this system. This contrasts with recent work suggesting that endoderm-derived TGFβ signalling supports the folding of the neural tube in a micropattern model comprising both mesendodermal and neurectodermal tissues ( Sahni et al, 2021 ). I should note that these two observations are not incompatible.…”

Defined Microenvironments Trigger In Vitro Gastrulation in Human Pluripotent Stem Cells

“…Bioengineered in vitro models have become powerful tools to study relationships between biophysical microenvironments and intracellular signaling pathways that align to specify cell fate in populations of pluripotent stem cells. [ 47 , 48 ] In recent years, micropatterned systems have shown how geometric confinement can guide cellular assembly, where triggering differentiation with soluble morphogens has led to in vitro models of embryogenesis, [ 12 , 13 , 49 ] neuroectoderm, [ 50 , 51 ] vascular, [ 17 , 52 ] and cardiac tissue. [ 22 ] While these models relied on soluble factors to initiate differentiation, here we demonstrated how pluripotent stem cells micropatterned on deformable substrates initiated in vitro morphogenesis‐like events through interactions with the substrate alone.…”

Self-organized anteroposterior regionalization of early midbrain and hindbrain using micropatterned human embryonic stem cells

“…We induced human ESCs into midbrain and hindbrain cells in the presence of low dosages of VPA and isotretinoin. Penicillin G was used as a non-teratogenic control since it has been shown that it does not disrupt neural tube development at its peak plasma concentration [44][45][46] . First, we performed cell proliferation assay to measure cell viability under treatment with different concentrations of these three tested drugs (Supplementary Figure 10).…”