Spatio-temporal control of 3D neuroepithelial tissue patterning
Human pluripotent stem cells (hPSC) have the amazing developmental potential of an embryo to different cell types in the body. However, hPSC tissue patterning is often spontaneous in conventional spheroid or monolayer cultures, which limits their translation into standardized experimental models for developmental diseases. Recent advances using stem cell micropatterning techniques have provided methods to achieve early embryonic spatial patterning which highlights its potential to generate spatially organized hPSC structure that can be related to human diseases.
The overall goal of this project is to achieve a directed formation of an ordered neuroepithelium structure from hPSCs which can be later developed to study a common class of birth defects known as neural tube defects. To achieve an ordered 3D neuroepithelium structure, cell micropatterning and a multi-step induction protocol was combined to achieve spatio-temporal control over hPSC differentiation. The stem cell micropatterning provides a spatial control over differentiation whereas the temporal control is achieved by mesoendoderm pre-patterning of hPSC micropatterns before neuropithelium induction to mimic the temporal embryonic developmental events, where mesoendoderm precedes neuroectoderm differentiation. This results in a formation of an organized 3D annular ring structure with distinct spatial patterning of Brachury+ mesoendoderm tissue and Sox2+ neuroepithelium tissue. We foresee this research as an important direction in 3D neuroepithelium tissue patterning with better-controlled organization and, therefore, function.
Environmental control of neural crest stem cells (NCSCs)
Craniofacial abnormalities are common human birth defects that include cleft palate and lips, and arise from any perturbations to the patterning, migration, proliferation, and differentiation of cranial neural crest cells (NCCs) during embryonic development. Currently, the understanding of the environmental factors involved in the spatiotemporal regulation of this developmental process is still very limited. This is partly due to the lack of an appropriate human craniofacial cellular model. We are interested to decipher soluble and physical environmental factors for the efficient derivation of human pluripotent stem cells (hPSCs) into cranial NCCs. The successful completion of this project will enable the efficient derivation of cranial NCCs from hESCs and potentially patient-specific human induced pluripotent stem cells (hiPSCs). Our plan is to build on this capability to generate human craniofacial developmental or disease models for either craniofacial regeneration or as in vitro screening models for drugs that potentiate craniofacial defects.