APOE3 Christchurch modulates ?-catenin/Wnt signaling in iPS cell-derived cerebral organoids from Alzheimer's cases
A patient with the PSEN1 E280A mutation and homozygous for APOE3 Christchurch (APOE3Ch) displayed extreme resistance to Alzheimer’s disease (AD) cognitive decline and tauopathy,despite having a high amyloid burden. To further investigate the differences in biological processes attributed to APOE3Ch,we generated induced pluripotent stem (iPS) cell-derived cerebral organoids from this resistant case and a non-protected control,using CRISPR/Cas9 gene editing to modulate APOE3Ch expression. In the APOE3Ch cerebral organoids,we observed a protective pattern from early tau phosphorylation. ScRNA sequencing revealed regulation of Cadherin and Wnt signaling pathways by APOE3Ch,with immunostaining indicating elevated ?-catenin protein levels. Further in vitro reporter assays unexpectedly demonstrated that ApoE3Ch functions as a Wnt3a signaling enhancer. This work uncovered a neomorphic molecular mechanism of protection of ApoE3 Christchurch,which may serve as the foundation for the future development of protected case-inspired therapeutics targeting AD and tauopathies.
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(May 2025)
Nature Communications 16
Deciphering signaling mechanisms and developmental dynamics in extraembryonic mesoderm specification from hESCs
Extraembryonic mesoderm (ExM) is crucial for human development,yet its specification is poorly understood. Human embryonic stem cell (hESC)-based models,including embryoids and differentiated derivatives,are emerging as promising tools for studying ExM development. Despite this,the signaling mechanisms and developmental dynamics that underlie ExM specification from hESCs remain challenging to study. Here,we report that the modulation of BMP,WNT,and Nodal signaling pathways can rapidly (4-5 days) and efficiently (?~90%) induce the differentiation of both naive and primed hESCs into ExM-like cells (ExMs). We reveal that ExM specification from hESCs predominantly proceeds through intermediates exhibiting a primitive streak (PS)-like gene expression pattern and delineate the regulatory roles of WNT and Nodal signaling in this process. Furthermore,we find that the initial pluripotent state governs hESC-based ExM specification by influencing signal response,cellular composition,developmental progression,and transcriptional characteristics of the resulting ExMs. Our study provides promising models for dissecting human ExM development and sheds light on the signaling principles,developmental dynamics,and influences of pluripotency states underlying ExM specification from hESCs. Extraembryonic mesoderm (ExM) is crucial but its formation is unclear. Here,authors develop efficient systems to specify ExM from hESCs and dissect the signaling mechanisms,specification dynamics,and impact of pluripotent states in ExM formation.
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(Sep 2024)
Theranostics 14 16
Single-cell profiling of brain pericyte heterogeneity following ischemic stroke unveils distinct pericyte subtype-targeted neural reprogramming potential and its underlying mechanisms
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.
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(Jun 2025)
Nature Communications 16
Forebrain neural progenitors effectively integrate into host brain circuits and improve neural function after ischemic stroke
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.
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(Sep 2024)
Nature Communications 15
Robust differentiation of human pluripotent stem cells into mural progenitor cells via transient activation of NKX3.1
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.
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Understanding retinal tau pathology through functional 2D and 3D iPSC-derived in vitro retinal models
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.
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(Nov 2024)
Nature Communications 15
High incidence and geographic distribution of cleft palate in Finland are associated with the IRF6 gene
In Finland,the frequency of isolated cleft palate (CP) is higher than that of isolated cleft lip with or without cleft palate (CL/P). This trend contrasts to that in other European countries but its genetic underpinnings are unknown. We conducted a genome-wide association study in the Finnish population and identified rs570516915,a single nucleotide polymorphism highly enriched in Finns,as strongly associated with CP (P?=?5.25 × 10?34,OR?=?8.65,95% CI 6.11–12.25),but not with CL/P (P?=?7.2 × 10?5),with genome-wide significance. The risk allele frequency of rs570516915 parallels the regional variation of CP prevalence in Finland,and the association was replicated in independent cohorts of CP cases from Finland (P?=?8.82 × 10?28) and Estonia (P?=?1.25 × 10?5). The risk allele of rs570516915 alters a conserved binding site for the transcription factor IRF6 within an enhancer (MCS-9.7) upstream of the IRF6 gene and diminishes the enhancer activity. Oral epithelial cells derived from CRISPR-Cas9 edited induced pluripotent stem cells demonstrate that the CP-associated allele of rs570516915 concomitantly decreases the binding of IRF6 and the expression level of IRF6,suggesting impaired IRF6 autoregulation as a molecular mechanism underlying the risk for CP. Here,the authors perform a genome-wide study and identify a genetic variant enriched in the Finnish population that is strongly associated with isolated cleft palate. This finding suggests a genetic basis for the high prevalence of cleft palate in Finland.
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(Jan 2025)
Scientific Reports 15 Suppl 4
Dysregulation of REST and its target genes impacts the fate of neural progenitor cells in down syndrome
Increasing shreds of evidence suggest that neurogenic-to-gliogenic shift may be critical to the abnormal neurodevelopment observed in individuals with Down syndrome (DS). REST,the Repressor Element-1 Silencing Transcription factor,regulates the differentiation and development of neural cells. Downregulation of REST may lead to defects in post-differentiation neuronal morphology in the brain of the DS fetal. This study aims to elucidate the role of REST in DS-derived NPCs using bioinformatics analyses and laboratory validations. We identified and validated vital REST-targeted DEGs: CD44,TGFB1,FN1,ITGB1,and COL1A1. Interestingly,these genes are involved in neurogenesis and gliogenesis in DS-derived NPCs. Furthermore,we identified nuclear REST loss and the neuroblast marker,DCX,was downregulated in DS human trisomic induced pluripotent stem cells (hiPSCs)-derived NPCs,whereas the glioblast marker,NFIA,was upregulated. Our findings indicate that the loss of REST is critical in the neurogenic-to-gliogenic shift observed in DS-derived NPCs. REST and its target genes may collectively regulate the NPC phenotype.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-87314-y.
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(May 2024)
Nature Communications 15
Fluorescent fatty acid conjugates for live cell imaging of peroxisomes
Peroxisomes are eukaryotic organelles that are essential for multiple metabolic pathways,including fatty acid oxidation,degradation of amino acids,and biosynthesis of ether lipids. Consequently,peroxisome dysfunction leads to pediatric-onset neurodegenerative conditions,including Peroxisome Biogenesis Disorders (PBD). Due to the dynamic,tissue-specific,and context-dependent nature of their biogenesis and function,live cell imaging of peroxisomes is essential for studying peroxisome regulation,as well as for the diagnosis of PBD-linked abnormalities. However,the peroxisomal imaging toolkit is lacking in many respects,with no reporters for substrate import,nor cell-permeable probes that could stain dysfunctional peroxisomes. Here we report that the BODIPY-C12 fluorescent fatty acid probe stains functional and dysfunctional peroxisomes in live mammalian cells. We then go on to improve BODIPY-C12,generating peroxisome-specific reagents,PeroxiSPY650 and PeroxiSPY555. These probes combine high peroxisome specificity,bright fluorescence in the red and far-red spectrum,and fast non-cytotoxic staining,making them ideal tools for live cell,whole organism,or tissue imaging of peroxisomes. Finally,we demonstrate that PeroxiSPY enables diagnosis of peroxisome abnormalities in the PBD CRISPR/Cas9 cell models and patient-derived cell lines. The array of tools to image peroxisome regulation is still limited. Here,the authors develop improved fatty acid-based probes with high peroxisome specificity and bright fluorescence in the red/far-red spectrum,which makes them ideal to study peroxisomes in live cells and whole organisms.
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(Jun 2025)
Experimental & Molecular Medicine 57 6
Changes in mitochondrial thymidine metabolism and mtDNA copy number during induced pluripotency
Somatic cell reprogramming into human induced pluripotent stem cells entails significant intracellular changes,including modifications in mitochondrial metabolism and a decrease in mitochondrial DNA copy number. However,the mechanisms underlying this decrease in mitochondrial DNA copy number during reprogramming remain unclear. Here we aimed to elucidate these underlying mechanisms. Through a meta-analysis of several RNA sequencing datasets,we identified genes responsible for the decrease in mitochondrial DNA. We investigated the functions of these identified genes and assessed their regulatory mechanisms. In particular,the expression of the thymidine kinase 2 gene (TK2),located in the mitochondria and required for mitochondrial DNA synthesis,is decreased in human pluripotent stem cells as compared with its expression in somatic cells. TK2 was significantly downregulated during reprogramming and markedly upregulated during differentiation. Collectively,this decrease in TK2 levels induces a decrease in mitochondrial DNA copy number and contributes to shaping the metabolic characteristics of human pluripotent stem cells. However,contrary to our expectations,treatment with a TK2 inhibitor impaired somatic cell reprogramming. These results suggest that decreased TK2 expression may result from metabolic conversion during somatic cell reprogramming. Mitochondrial DNA loss linked to stem cell reprogrammingInduced pluripotent stem (iPS) cells are special cells created by reprogramming regular body cells. Researchers explored how these cells change their energy production methods during reprogramming. The study focused on a protein called thymidine kinase 2 (TK2),which is important for maintaining mitochondrial DNA (mtDNA). Mitochondria are the cell’s powerhouses,and their DNA is crucial for energy production. Researchers used human cell lines to study how TK2 affects mtDNA during reprogramming. They found that,as cells become iPS cells,TK2 levels drop,leading to reduced mtDNA and a shift in energy production from oxidative phosphorylation to glycolysis. Results suggest that reducing TK2 and mtDNA is key for cells to gain pluripotency. This shift helps support the rapid growth and development of iPS cells. Understanding this process could improve stem cell therapies and regenerative medicine in the future.This summary was initially drafted using artificial intelligence,then revised and fact-checked by the author.
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(Apr 2024)
Signal Transduction and Targeted Therapy 9
FGF7 enhances the expression of ACE2 in human islet organoids aggravating SARS-CoV-2 infection
The angiotensin-converting enzyme 2 (ACE2) is a primary cell surface viral binding receptor for SARS-CoV-2,so finding new regulatory molecules to modulate ACE2 expression levels is a promising strategy against COVID-19. In the current study,we utilized islet organoids derived from human embryonic stem cells (hESCs),animal models and COVID-19 patients to discover that fibroblast growth factor 7 (FGF7) enhances ACE2 expression within the islets,facilitating SARS-CoV-2 infection and resulting in impaired insulin secretion. Using hESC-derived islet organoids,we demonstrated that FGF7 interacts with FGF receptor 2 (FGFR2) and FGFR1 to upregulate ACE2 expression predominantly in ? cells. This upregulation increases both insulin secretion and susceptibility of ? cells to SARS-CoV-2 infection. Inhibiting FGFR counteracts the FGF7-induced ACE2 upregulation,subsequently reducing viral infection and replication in the islets. Furthermore,retrospective clinical data revealed that diabetic patients with severe COVID-19 symptoms exhibited elevated serum FGF7 levels compared to those with mild symptoms. Finally,animal experiments indicated that SARS-CoV-2 infection increased pancreatic FGF7 levels,resulting in a reduction of insulin concentrations in situ. Taken together,our research offers a potential regulatory strategy for ACE2 by controlling FGF7,thereby protecting islets from SARS-CoV-2 infection and preventing the progression of diabetes in the context of COVID-19.
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