技术资料

Friedreich ataxia (FRDA) is a multisystemic,autosomal recessive disorder caused by homozygous GAA expansion mutation in the first intron of frataxin (FXN) gene. FXN is a mitochondrial protein critical for iron-sulfur cluster biosynthesis and deficiency impairs mitochondrial electron transport chain functions and iron homeostasis within the organelle. Currently,there is no effective treatment for FRDA. We have previously demonstrated that single infusion of wild-type hematopoietic stem and progenitor cells (HSPCs) resulted in prevention of neurologic and cardiac complications of FRDA in YG8R mice,and rescue was mediated by FXN transfer from tissue engrafted,HSPC-derived microglia/macrophages to diseased neurons/myocytes. For a future clinical translation,we developed an autologous stem cell transplantation approach using CRISPR/Cas9 for the excision of the GAA repeats in FRDA patients’ CD34+ HSPCs; this strategy leading to increased FXN expression and improved mitochondrial functions. The aim of the current study is to validate the efficiency and safety of our gene editing approach in a disease-relevant model. We generated a cohort of FRDA patient-derived iPSCs and isogenic lines that were gene edited with our CRISPR/Cas9 approach. iPSC derived FRDA neurons displayed characteristic apoptotic and mitochondrial phenotype of the disease,such as non-homogenous microtubule staining in neurites,increased caspase-3 expression,mitochondrial superoxide levels,mitochondrial fragmentation,and partial degradation of the cristae compared to healthy controls. These defects were fully prevented in the gene edited neurons. RNASeq analysis of FRDA and gene edited neurons demonstrated striking improvement in gene clusters associated with endoplasmic reticulum (ER) stress in the isogenic lines. Gene edited neurons demonstrated improved ER-calcium release,normalization of ER stress response gene,XBP-1,and significantly increased ER-mitochondrial contacts that are critical for functional homeostasis of both organelles,as compared to FRDA neurons. Ultrastructural analysis for these contact sites displayed severe ER structural damage in FRDA neurons,that was undetected in gene edited neurons. Taken together,these results represent a novel finding for disease pathogenesis showing dramatic ER structural damage in FRDA,validate the efficacy profile of our FXN gene editing approach in a disease relevant model,and support our approach as an effective strategy for therapeutic intervention for Friedreich’s ataxia. View Publication

A growing body of knowledge implicates perturbed RNA homeostasis in amyotrophic lateral sclerosis (ALS),a neurodegenerative disease that currently has no cure and few available treatments. Dysregulation of the multifunctional RNA-binding protein TDP-43 is increasingly regarded as a convergent feature of this disease,evidenced at the neuropathological level by the detection of TDP-43 pathology in most patient tissues,and at the genetic level by the identification of disease-associated mutations in its coding gene TARDBP. To characterize the transcriptional landscape induced by TARDBP mutations,we performed whole-transcriptome profiling of motor neurons (MNs) differentiated from two knock-in iPSC lines expressing the ALS-linked TDP-43 variants p.A382T or p.G348C. Our results show that the TARDBP mutations significantly altered the expression profiles of mRNAs and microRNAs of the 14q32 cluster in MNs. Using mutation-induced gene signatures and the Connectivity Map database,we identified compounds predicted to restore gene expression toward wild-type levels. Among top-scoring compounds selected for further investigation,the NEDD8-activating enzyme inhibitor MLN4924 effectively improved cell viability and neuronal activity,highlighting a possible role for protein post-translational modification via NEDDylation in the pathobiology of TDP-43 in ALS.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-12147-8. View Publication

Diabetes mellitus,a chronic and non-transmissible disease,triggers a wide range of micro- and macrovascular complications. The differentiation of pancreatic ?-like cells (P?LCs) from induced pluripotent stem cells (iPSCs) offers a promising avenue for regenerative medicine aimed at treating diabetes. Current differentiation protocols strive to emulate pancreatic embryonic development by utilizing cytokines and small molecules at specific doses to activate and inhibit distinct molecular signaling pathways,directing the differentiation of iPSCs into pancreatic ? cells. Despite significant progress and improved protocols,the full spectrum of molecular signaling pathways governing pancreatic development and the physiological characteristics of the differentiated cells are not yet fully understood. Here,we report a specific combination of cofactors and small molecules that successfully differentiate iPSCs into P?LCs. Our protocol has shown to be effective,with the resulting cells exhibiting key functional properties of pancreatic ? cells,including the expression of crucial molecular markers (pdx1,nkx6.1,ngn3) and the capability to secrete insulin in response to glucose. Furthermore,the addition of vitamin C and retinoic acid in the final stages of differentiation led to the overexpression of specific ? cell genes. View Publication

SummaryCell size is a crucial physical property that significantly impacts cellular physiology and function. However,the influence of cell size on stem cell specification remains largely unknown. Here,we investigated the dynamic changes in cell size during the differentiation of human pluripotent stem cells into definitive endoderm (DE). Interestingly,cell size exhibited a gradual decrease as DE differentiation progressed with higher stiffness. Furthermore,the application of hypertonic pressure or chemical to accelerate the reduction in cell size significantly and specifically enhanced DE differentiation. By functionally intervening in mechanosensitive elements,we have identified actomyosin activity as a crucial mediator of both DE differentiation and cell size reduction. Mechanistically,the reduction in cell size induces actomyosin-dependent angiomotin (AMOT) nuclear translocation,which suppresses Yes-associated protein (YAP) activity and thus facilitates DE differentiation. Together,our study has established a novel connection between cell size diminution and DE differentiation,which is mediated by AMOT nuclear translocation. Additionally,our findings suggest that the application of osmotic pressure can effectively promote human endodermal lineage differentiation. Graphical abstract Highlights•Cell size decreases during the differentiation of human pluripotent stem cells into endoderm•Hypertonic pressure is conducive to the differentiation of human definitive endoderm•Actomyosin contributes to both size diminution and endoderm promotion under hypertonic pressure•Cell size diminution represses YAP activity via promoting AMOT nuclear translocation Jiang and colleagues show that cell size exhibits a gradual decrease during human endoderm differentiation. The application of hypertonic pressure or chemical to accelerate the reduction in cell size significantly and specifically enhanced endoderm differentiation. This enhancement is reliant on actomyosin activity and achieved by promoting the nuclear translocation of AMOT,thereby repressing YAP activity. View Publication

SummaryPattern recognition receptors (PRRs) induce host defense but can also induce exacerbated inflammatory responses. This raises the question of whether other mechanisms are also involved in early host defense. Using transcriptome analysis of disrupted transcripts in herpes simplex virus (HSV)-infected cells,we find that HSV infection disrupts the hypoxia-inducible factor (HIF) transcription network in neurons and epithelial cells. Importantly,HIF activation leads to control of HSV replication. Mechanistically,HIF activation induces autophagy,which is essential for antiviral activity. HSV-2 infection in vivo leads to hypoxia in CNS neurons,and mice with neuron-specific HIF1/2? deficiency exhibit elevated viral load and augmented PRR signaling and inflammatory gene expression in the CNS after HSV-2 infection. Data from human stem cell-derived neuron and microglia cultures show that HIF also exerts antiviral and inflammation-restricting activity in human CNS cells. Collectively,the HIF transcription factor system senses virus-induced hypoxic stress to induce cell-intrinsic antiviral responses and limit inflammation. Graphical abstract Highlights•HSV-1 and -2 disrupt the hypoxia-inducible factor (HIF) network in permissive cells•HIF activation induces autophagy,which exerts anti-HSV activity in neurons•Neuronal HIF activation regulates infection and inflammation in the infected brain Using transcriptome analysis of disrupted transcripts in herpes simplex virus-infected cells,Farahani et al. identify the hypoxia-inducible factor gene network to possess antiviral activity through induction of autophagy. This contributes to antiviral defense and regulation of inflammation during infection in the CNS. View Publication

Diabetes involves the death or dysfunction of pancreatic ?-cells. Analysis of bulk sequencing from human samples and studies using in vitro and in vivo models suggest that endoplasmic reticulum and inflammatory signaling play an important role in diabetes progression. To better characterize cell type-specific stress response,we perform multiplexed single-cell RNA sequencing to define the transcriptional signature of primary human islet cells exposed to endoplasmic reticulum and inflammatory stress. Through comprehensive pair-wise analysis of stress responses across pancreatic endocrine and exocrine cell types,we define changes in gene expression for each cell type under different diabetes-associated stressors. We find that ?-,?-,and ductal cells have the greatest transcriptional response. We utilize stem cell-derived islets to study islet health through the candidate gene CIB1,which was upregulated under stress in primary human islets. Our findings provide insights into cell type-specific responses to diabetes-associated stress and establish a resource to identify targets for diabetes therapeutics. Endoplasmic reticulum and inflammatory stress are associated with diabetes. Maestas et al. use single-cell sequencing to profile primary human islets under stress and identified tissue and cell-type responses. View Publication

To uncover molecular changes underlying blood-brain-barrier dysfunction in Alzheimer’s disease,we performed single nucleus RNA sequencing in 24 Alzheimer’s disease and control brains and focused on vascular and astrocyte clusters as main cell types of blood-brain-barrier gliovascular-unit. The majority of the vascular transcriptional changes were in pericytes. Of the vascular molecular targets predicted to interact with astrocytic ligands,SMAD3,upregulated in Alzheimer’s disease pericytes,has the highest number of ligands including VEGFA,downregulated in Alzheimer’s disease astrocytes. We validated these findings with external datasets comprising 4,730 pericyte and 150,664 astrocyte nuclei. Blood SMAD3 levels are associated with Alzheimer’s disease-related neuroimaging outcomes. We determined inverse relationships between pericytic SMAD3 and astrocytic VEGFA in human iPSC and zebrafish models. Here,we detect vast transcriptome changes in Alzheimer’s disease at the gliovascular-unit,prioritize perturbed pericytic SMAD3-astrocytic VEGFA interactions,and validate these in cross-species models to provide a molecular mechanism of blood-brain-barrier disintegrity in Alzheimer’s disease. Systematic studies are needed to discover molecular determinants of blood brain barrier dysfunction in Alzheimer’s disease. This study identifies perturbed pericytic SMAD3-astrocytic VEGFA interactions as a potential driver of this dysfunction. View Publication

Disease modeling with isogenic Induced Pluripotent Stem Cell (iPSC)-differentiated organoids serves as a powerful technique for studying disease mechanisms. Multiplexed coculture is crucial to mitigate batch effects when studying the genetic effects of disease-causing variants in differentiated iPSCs or organoids,and demultiplexing at the single-cell level can be conveniently achieved by assessing natural genetic barcodes. Here,to enable cost-efficient time-series experimental designs via multiplexed bulk and single-cell RNA-seq of hybrids,we introduce a computational method in our Vireo Suite,Vireo-bulk,to effectively deconvolve pooled bulk RNA-seq data by genotype reference,and thereby quantify donor abundance over the course of differentiation and identify differentially expressed genes among donors. Furthermore,with multiplexed scRNA-seq and bulk RNA-seq,we demonstrate the usefulness and necessity of a pooled design to reveal donor iPSC line heterogeneity during macrophage cell differentiation and to model rare WT1 mutation-driven kidney disease with chimeric organoids. Our work provides an experimental and analytic pipeline for dissecting disease mechanisms with chimeric organoids. IPSC-derived organoids model diseases. Multiplexed coculture and demultiplexing natural genetic barcodes aid in studying genetic effects. Here,authors introduce Vireo-bulk to deconvolve bulk RNA-seq data,quantify donor abundance and identify differentially expressed genes. View Publication

Stargardt disease (STGD),predominantly caused by mutations in the ABCA4 gene,is a leading cause of inherited retinal degeneration. Although several lines of mice expressing disease-causing variants have been produced,mice due to the lack of macular may not be the perfect model to mimic the characteristics of STGD. To address this knowledge gap,we generated retinal organoids from patient-derived induced pluripotent stem cells (iPSCs) harboring ABCA4 mutations and performed biological validation. The generated retinal organoids were subjected to single-cell RNA sequencing (scRNA-seq) at major developmental stages (40,90,150,200,and 260 days),and we additionally compared the transcriptomics with our recently published control retinal organoids to further confirm the reliability of the dataset. By using iPSCs carrying most common variant in Chinese STGD patients,the dataset not only provides a powerful resource for studying STGD,but also offers novels insight into the developmental mechanisms underlying ABCA4-associated pathological changes in the retinal organoid system. View Publication

SummaryGlioblastomas are the most common malignant brain tumors in adults; they are highly aggressive and heterogeneous and show a high degree of plasticity. Here,we show that methyltransferase-like 7B (METTL7B) is an essential regulator of lineage specification in glioblastoma,with an impact on both tumor size and invasiveness. Single-cell transcriptomic analysis of these tumors and of cerebral organoids derived from expanded potential stem cells overexpressing METTL7B reveal a regulatory role for the gene in the neural stem cell-to-astrocyte differentiation trajectory. Mechanistically,METTL7B downregulates the expression of key neuronal differentiation players,including SALL2,via post-translational modifications of histone marks. Graphical abstract Highlights•METTL7B is highly expressed in human glioblastoma stem cells•METTL7B regulates tumor size and invasiveness in an in vivo xenograft model•METTL7B controls the neural stem cell-to-astrocyte differentiation trajectory•METTL7B regulates SALL2 expression via H3K27me3 modulation Constantinou et al. identify METTL7B as an essential regulator of lineage specification and a modulator of the expression of the transcription factor SALL2 with wide-ranging impacts on invasion and tumor growth in glioblastoma. View Publication