Boukhaddaoui, H. | bioRxiv Science

bioRxiv2026

Neocortical astrocyte diversity stems from distinct developmental origins

Key regulators of neural network activity in multiple advanced cognitive processes and essential components of the blood-brain barrier, astrocytes constitute a highly heterogeneous population at the morphological, molecular, and functional levels. However, how this diversity arises during mammalian brain development remains poorly investigated. Here, using a combination of multicolour genetic fate mapping, single-cell transcriptomic analyses, multichannel large-volume imaging and detailed 3D cell morphology reconstructions, we uncover a discrete subpopulation of neocortical astrocytes generated from an early restricted embryonic domain located outside of the dorsal pallium. Besides their separate lineage from pyramidal neurons, these astrocytes exhibit a developmental trajectory that differs from astrocytes produced by dorsal cortical progenitors, including different migratory pathways, spatial distributions and morphology. Overall, our results reveal the diversity of embryonic sources responsible for neocortical astrocyte genesis and provide key insights into the unsuspected complex developmental processes that underlie cortical astrocyte heterogeneity.

neuroscience↗

bioRxiv2020

Differentiation of human induced pluripotent stem cells into functional airway epithelium

RationaleHighly reproducible in vitro generation of human bronchial epithelium from pluripotent stem cells is an unmet key goal for drug screening to treat lung diseases. The possibility of using induced pluripotent stem cells (hiPSC) to model normal and diseased tissue in vitro from a simple blood sample will reshape drug discovery for chronic lung, monogenic and infectious diseases. MethodsWe devised a simple and reliable method that drives a blood sample reprogrammed into hiPSC subsequently differentiated within 45 days into air-liquid interface bronchial epithelium (iALI), through key developmental stages, definitive-endoderm (DE) and Ventralized-Anterior-Foregut-Endoderm (vAFE) cells. ResultsReprogramming blood cells from one healthy and 3 COPD patients, and from skin-derived fibroblasts obtained in one PCD patient, succeeded in 100% of samples using Sendai viruses. Mean cell purity at DE and vAFE stages was greater than 80%, assessed by expression of CXCR4 and NKX2.1, avoiding the need of cell sorting. When transferred to ALI conditions, vAFE cells reliably differentiated within 4 weeks into bronchial epithelium with large zones covered by beating ciliated, basal, goblets, club cells and neuroendocrine cells as found in vivo. Benchmarking all culture conditions including hiPSCs adaptation to single-cell passaging, cell density and differentiation induction timing allowed for consistently producing iALI bronchial epithelium from the five hiPSC lines. ConclusionsReliable reprogramming and differentiation of blood-derived hiPSCs into mature and functional iALI bronchial epithelium is ready for wider use and this will allow better understanding lung disease pathogenesis and accelerating the development of novel gene therapies and drug discovery.

bioengineering↗