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Rationale: Brain pericytes can acquire multipotency to produce multi-lineage cells following injury. However, pericytes are a heterogenous population and it remains unknown whether there are different potencies from different subsets of pericytes in response to injury.Methods: We used an ischemic stroke model combined with pericyte lineage tracing animal models to investigate brain pericyte heterogeneity under both naïve and brain injury conditions via single-cell RNA-sequencing and immunohistochemistry analysis. In addition, we developed an NG2+ pericyte neural reprogramming culture model from both murine and humans to unveil the role of energy sensor, AMP-dependent kinase (AMPK), activity in modulating the reprogramming/differentiation process to convert pericytes to functional neurons by targeting a Ser 436 phosphorylation on CREB-binding protein (CBP), a histone acetyltransferase.Results: We showed that two distinct pericyte subpopulations, marked by NG2+ and Tbx18+, had different potency following brain injury. NG2+ pericytes expressed dominant neural reprogramming potential to produce newborn neurons, while Tbx18+ pericytes displayed dominant multipotency to produce endothelial cells, fibroblasts, and microglia following ischemic stroke. In addition, we discovered that AMPK modulators facilitated pericyte-to-neuron conversion by modulating Ser436 phosphorylation status of CBP, to coordinate an acetylation shift between Sox2 and histone H2B, and to regulate Sox2 nuclear-cytoplasmic trafficking during the reprogramming/differentiation process. Finally, we showed that sequential treatment of compound C (CpdC) and metformin, AMPK inhibitor and activator respectively, robustly facilitated the conversion of human pericytes into functional neurons.Conclusion: We revealed that two distinct subtypes of pericytes possess different reprogramming potencies in response to physical and ischemic injuries. We also developed a genomic integration-free methodology to reprogram human pericytes into functional neurons by targeting NG2+ pericytes.

Human cortical neural progenitor cell transplantation holds significant potential in cortical stroke treatment by replacing lost cortical neurons and repairing damaged brain circuits. However, commonly utilized human cortical neural progenitors are limited in yield a substantial proportion of diverse cortical neurons and require an extended period to achieve functional maturation and synaptic integration, thereby potentially diminishing the optimal therapeutic benefits of cell transplantation for cortical stroke. Here, we generated forkhead box G1 (FOXG1)-positive forebrain progenitors from human inducible pluripotent stem cells, which can differentiate into diverse and balanced cortical neurons including upper- and deep-layer excitatory and inhibitory neurons, achieving early functional maturation simultaneously in vitro. Furthermore, these FOXG1 forebrain progenitor cells demonstrate robust cortical neuronal differentiation, rapid functional maturation and efficient synaptic integration after transplantation into the sensory cortex of stroke-injured adult rats. Notably, we have successfully utilized the non-invasive 18F-SynVesT-1 PET imaging technique to assess alterations in synapse count before and after transplantation therapy of FOXG1 progenitors in vivo. Moreover, the transplanted FOXG1 progenitors improve sensory and motor function recovery following stroke. These findings provide systematic and compelling evidence for the suitability of these FOXG1 progenitors for neuronal replacement in ischemic cortical stroke. Human NPCs show promise for stroke treatment, but challenges remain in neuron diversity and maturation time. Here, the authors describe the generation of FOXG1 progenitors from iPSCs that quickly mature into functional cortical neurons, enhancing stroke recovery in rats.

Mural cells are central to vascular integrity and function. In this study, we demonstrate the innovative use of the transcription factor NKX3.1 to guide the differentiation of human induced pluripotent stem cells into mural progenitor cells (iMPCs). By transiently activating NKX3.1 in mesodermal intermediates, we developed a method that diverges from traditional growth factor-based differentiation techniques. This approach efficiently generates a robust iMPC population capable of maturing into diverse functional mural cell subtypes, including smooth muscle cells and pericytes. These iMPCs exhibit key mural cell functionalities such as contractility, deposition of extracellular matrix, and the ability to support endothelial cell-mediated vascular network formation in vivo. Our study not only underscores the fate-determining significance of NKX3.1 in mural cell differentiation but also highlights the therapeutic potential of these iMPCs. We envision these insights could pave the way for a broader use of iMPCs in vascular biology and regenerative medicine. Mural progenitor cells are crucial for vascular stability. Here, the authors generate these cells from human pluripotent stem cells using NKX3.1 and show that they can mature into various mural cell types and contribute to blood vessel formation.

The generation of retinal models from human induced pluripotent stem cells holds significant potential for advancing our understanding of retinal development, neurodegeneration, and the in vitro modeling of neurodegenerative disorders. The retina, as an accessible part of the central nervous system, offers a unique window into these processes, making it invaluable for both study and early diagnosis. This study investigates the impact of the Frontotemporal Dementia-linked IVS 10?+?16 MAPT mutation on retinal development and function using 2D and 3D retinal models derived from human induced pluripotent stem cells. Our findings reveal that the MAPT mutation leads to delayed retinal cell differentiation and maturation, with tau-mutant disease models exhibiting sustained higher expression of retinal progenitor cell markers and a reduced presence of post-mitotic neurons. Both 2D and 3D tau-mutant retinal models demonstrated an imbalance in tau isoforms, favoring 4R tau, along with increased tau phosphorylation, altered neurite morphology, and impaired cytoskeletal maturation. These changes are associated with impaired synaptic development, reduced neuronal connectivity, and enhanced cellular stress responses, including the increased formation of stress granules, markers of apoptosis and autophagy, and the presence of intracellular toxic tau aggregates. This study highlights the value of retinal models derived from human induced pluripotent stem cells in exploring the mechanisms underlying retinal pathology associated with tau mutations. These models offer essential insights into the development of therapeutic strategies for neurodegenerative diseases characterized by tau aggregation.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40478-024-01920-x.