技术资料

The significant advances in the differentiation of human pluripotent stem (hPS) cells into pancreatic endocrine cells,including functional ?-cells,have been based on a detailed understanding of the underlying developmental mechanisms. However,the final differentiation steps,leading from endocrine progenitors to mono-hormonal and mature pancreatic endocrine cells,remain to be fully understood and this is reflected in the remaining shortcomings of the hPS cell-derived islet cells (SC-islet cells),which include a lack of ?-cell maturation and variability among different cell lines. Additional signals and modifications of the final differentiation steps will have to be assessed in a combinatorial manner to address the remaining issues and appropriate reporter lines would be useful in this undertaking. Here we report the generation and functional validation of hPS cell reporter lines that can monitor the generation of INS+ and GCG+ cells and their resolution into mono-hormonal cells (INSeGFP,INSeGFP/GCGmCHERRY) as well as ?-cell maturation (INSeGFP/MAFAmCHERRY) and function (INSGCaMP6). The reporter hPS cell lines maintained strong and widespread expression of pluripotency markers and differentiated efficiently into definitive endoderm and pancreatic progenitor (PP) cells. PP cells from all lines differentiated efficiently into islet cell clusters that robustly expressed the corresponding reporters and contained glucose-responsive,insulin-producing cells. To demonstrate the applicability of these hPS cell reporter lines in a high-content live imaging approach for the identification of optimal differentiation conditions,we adapted our differentiation procedure to generate SC-islet clusters in microwells. This allowed the live confocal imaging of multiple SC-islets for a single condition and,using this approach,we found that the use of the N21 supplement in the last stage of the differentiation increased the number of monohormonal ?-cells without affecting the number of ?-cells in the SC-islets. The hPS cell reporter lines and the high-content live imaging approach described here will enable the efficient assessment of multiple conditions for the optimal differentiation and maturation of SC-islets. View Publication

AbstractA GGGGCC (G4C2) hexanucleotide repeat expansion in C9ORF72 causes amyotrophic lateral sclerosis and frontotemporal dementia (C9ALS/FTD),while a CGG trinucleotide repeat expansion in FMR1 leads to the neurodegenerative disorder Fragile X-associated tremor/ataxia syndrome (FXTAS). These GC-rich repeats form RNA secondary structures that support repeat-associated non-AUG (RAN) translation of toxic proteins that contribute to disease pathogenesis. Here we assessed whether these same repeats might trigger stalling and interfere with translational elongation. We find that depletion of ribosome-associated quality control (RQC) factors NEMF,LTN1 and ANKZF1 markedly boost RAN translation product accumulation from both G4C2 and CGG repeats while overexpression of these factors reduces RAN production in both reporter assays and C9ALS/FTD patient iPSC-derived neurons. We also detected partially made products from both G4C2 and CGG repeats whose abundance increased with RQC factor depletion. Repeat RNA sequence,rather than amino acid content,is central to the impact of RQC factor depletion on RAN translation—suggesting a role for RNA secondary structure in these processes. Together,these findings suggest that ribosomal stalling and RQC pathway activation during RAN translation inhibits the generation of toxic RAN products. We propose augmenting RQC activity as a therapeutic strategy in GC-rich repeat expansion disorders. Graphical Abstract Graphical Abstract View Publication

BackgroundAmyloid-beta (A?) plaques and their associated glial responses are hallmark features of Alzheimer’s disease (AD),yet their interactions within the human brain remain poorly defined.MethodsWe applied spatial transcriptomics (ST) and immunohistochemistry (IHC) to 78 postmortem brain sections from 21 individuals in the Religious Orders Study and Memory and Aging Project (ROSMAP). We paired ST with histological data and stratified spots into major categories of plaque-glia niches based on A?,GFAP,and IBA1 intensity. Leveraging published ROSMAP single-nucleus RNA-seq data,we examined differences in gene expression,cellular composition,and intercellular communication across these niches. Neuronal and glial changes were validated by IHC and quantitative analyses. We further characterized glial responses using gene set enrichment analysis (GSEA) with known mouse glial signatures and human AD-associated microglial states. Finally,we used iPSC-derived multicellular cultures and single-cell RNA sequencing (scRNA-seq) to identify cell types that,upon short-term A? exposure,recapitulate the glial responses observed in the human spatial data.ResultsLow-A? regions,enriched for diffuse plaques,exhibited transcriptomic profiles consistent with greater neuronal loss than high-A? regions. High-glia regions showed increased expression of inflammatory and neurodegenerative pathways. Spatial glial responses aligned with established gene modules,including plaque-induced genes (PIGs),oligodendrocyte (OLIG) responses,disease-associated microglia (DAM),disease-associated astrocytes (DAA),and human AD-associated microglial states,indicating that diverse glial phenotypes emerge around plaques and shape the local immune environment. IHC confirmed elevated neuronal apoptosis near low-A? plaques and greater CD68 abundance and synaptic loss near glia-high plaques. In vitro,iPSC-derived microglia—but not astrocytes—exposed to A? displayed transcriptomic changes that closely mirrored the glial states identified in our ST dataset.ConclusionsOur study provides a comprehensive spatial transcriptomic dataset from human AD brain tissue and bridges spatial gene expression with traditional neuropathology. By integrating ST,snRNA-seq,and human multicellular models,we map cellular states and molecular events within plaque-glia niches. This work offers a spatially resolved framework for dissecting plaque-glia interactions and reveals new insights into the cellular and molecular heterogeneity underlying neurodegenerative pathology.Supplementary InformationThe online version contains supplementary material available at 10.1186/s44477-025-00002-z. View Publication

Mutation in CUL4B gene is one of the most common causes for X-linked intellectual disability (XLID). CUL4B is the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complex. While the roles of CUL4B in cancer progression and some developmental processes like adipogenesis,osteogenesis,and spermatogenesis have been studied,the mechanisms underlying the neurological disorders in patients with CUL4B mutations are poorly understood. Here,using 2D neuronal culture and cerebral organoids generated from the patient-derived induced pluripotent stem cells and their isogenic controls,we demonstrate that CUL4B is required to prevent premature cell cycle exit and precocious neuronal differentiation of neural progenitor cells. Moreover,loss-of-function mutations of CUL4B lead to increased synapse formation and enhanced neuronal excitability. Mechanistically,CRL4B complex represses transcription of PPP2R2B and PPP2R2C genes,which encode two isoforms of the regulatory subunit of protein phosphatase 2 A (PP2A) complex,through catalyzing monoubiquitination of H2AK119 in their promoter regions. CUL4B mutations result in upregulated PP2A activity,which causes inhibition of AKT and ERK,leading to premature cell cycle exit. Activation of AKT and ERK or inhibition of PP2A activity in CUL4B mutant organoids rescues the neurogenesis defect. Our work unveils an essential role of CUL4B in human cortical development. View Publication

Human GWAS have shown that obesogenic FTO polymorphisms correlate with lean mass,but the mechanisms have remained unclear. It is counterintuitive because lean mass is inversely correlated with obesity and metabolic diseases. Here,we use CRISPR to knock-in FTOrs9939609-A into hESC-derived tissue models,to elucidate potentially hidden roles of FTO during development. We find that among human tissues,FTOrs9939609-A most robustly affect human muscle progenitors’ proliferation,differentiation,senescence,thereby accelerating muscle developmental and metabolic aging. An edited FTOrs9939609-A allele over-stimulates insulin/IGF signaling via increased muscle-specific enhancer H3K27ac,FTO expression and m6A demethylation of H19 lncRNA and IGF2 mRNA,with excessive insulin/IGF signaling leading to insulin resistance upon replicative aging or exposure to high fat diet. This FTO-m6A-H19/IGF2 circuit may explain paradoxical GWAS findings linking FTOrs9939609-A to both leanness and obesity. Our results provide a proof-of-principle that CRISPR-hESC-tissue platforms can be harnessed to resolve puzzles in human metabolism. Human GWAS paradoxically linked FTO SNPs to both lean mass and sarcopenia/obesity. Here,Guang et al used CRISPR-edited stem cells to reveal that an obesogenic FTO SNP accelerates both muscle development and aging,by increasing RNA m6A demethylation. View Publication

It has been reported that human embryonic stem cells (hESCs) treated with BMP4 and inhibitors of TGF? signaling (A83-01) and FGF signaling (PD173074),called BAP,can efficiently differentiate to extraembryonic (ExE) cells in vitro. Due to restricted access to human embryos,it is ethically impossible to test the developmental potential of ExE cells in vivo. Here,we demonstrate that most ExE cells expressed molecular markers for both trophoblasts (TBs) and amniotic cells (ACs). Following intra-uterine transplantation,ExE cells contributed to the mouse placenta. More interestingly,ExE cells could chimerize with the mouse blastocyst as,after injection into the blastocyst,they penetrated its trophectoderm. After implantation of the injected blastocysts into surrogate mice,human cells were found at E14 in placental labyrinth,junction zones,and even near the uterine decidua,expressed placental markers,and secreted human chorionic gonadotropin. Surprisingly,ExE cells also contributed to cartilages of the chimeric embryo with some expressing the chondrogenic marker SOX9,consistent with the mesodermal potential of TBs and ACs in the placenta. Deleting MSX2,a mesodermal determinant,restricted the contribution of ExE cells to the placenta. Thus,we conclude that hESC-derived ExE cells can chimerize with the mouse blastocyst and contribute to both the placenta and cartilages of the chimera consistent with their heteogenious nature. Intra-uterus and intra-blastocyst injections are novel and sensitive methods to study the developmental potential of ExE cells. View Publication

Presynaptic scaffold proteins,including liprin-?,RIM,and ELKS,are pivotal to the assembly of the active zone and regulating the coupling of calcium signals and neurotransmitter release,yet the underlying mechanism remains poorly understood. Here,we determined the crystal structure of the liprin-?2/RIM1 complex,revealing a multifaceted intermolecular interaction that drives the liprin-?/RIM assembly. Neurodevelopmental disease-associated mutations block the formation of the complex. Disrupting this interaction in cultured human neurons impairs synaptic transmission and reduces the readily releasable pool of synaptic vesicles. Super-resolution imaging analysis supports a role for liprin-? in recruiting RIM1 to the active zone,presumably by promoting the liquid–liquid phase separation (LLPS) of RIM1. Strikingly,the liprin-?/RIM interaction modulates the competitive distribution of ELKS1 and voltage-gated Ca2+ channels (VGCCs) in RIM1 condensates. Disrupting the liprin-?/RIM interaction significantly decreased VGCC accumulation in the condensed phase and rendered release more sensitive to the slow calcium buffer EGTA,suggesting an increased physical distance between VGCC and vesicular calcium sensors. Together,our findings provide a plausible mechanism of the liprin-?/RIM complex in regulating the coupling of calcium channels and primed synaptic vesicles via LLPS for efficient synaptic transmission and uncover the pathological implication of liprin-? mutations in neurodevelopmental disorders. Scaffolding proteins regulate the assembly of the active zone in presynaptic terminals,but the mechanisms of assembly remain poorly understood. This study solves the crystal structure of the liprin-?2/RIM1 complex and shows that this interaction is essential for synaptic transmission and the coupling of calcium channels with primed synaptic vesicles in an LLPS-dependent manner. View Publication

BackgroundSmall extracellular vesicles (EVs),exemplified by exosomes,mediate intercellular communication by transporting proteins,mRNAs,and miRNAs. Post-translational modifications are involved in controlling small EV secretion process. However,whether palmitoylation regulates small EV secretion,remains largely unexplored.MethodsVacuole Membrane Protein 1 (VMP1) was testified to be S-palmitoylated by Palmitoylation assays. VMP1 mutant plasmids were constructed to screen out the exact palmitoylation sites. Small EVs were isolated,identified and compared between wild-type VMP1 or mutant VMP1 transfected cells. Electron microscope and immunofluorescence were used to detect multivesicular body (MVB) number and morphology change when VMP1 was mutated. Immunoprecipitation and Mass spectrum were adopted to identify the protein that interacted with palmitoylated VMP1,while knock down experiment was used to explore the function of targeted protein ALIX. Taking human Sertoli cells (SCs) and human spermatogonial stem cell like cells (SSCLCs) as a model of intercellular communication,SSCLC maintenance was detected by flow cytometry and qPCR at 12 days of differentiation. In vivo,mouse model was established by intraperitoneal injection with palmitoylation inhibitor,2-bromopalmitate (2BP) for 3 months.ResultsVMP1 was identified to be palmitoylated at cysteine 263,278 by ZDHHC3. Specifically,palmitoylation of VMP1 regulated its subcellular location and enhanced the amount of small EV secretion. Mutation of VMP1 palmitoylation sites interfered with the morphology and biogenesis of MVBs through suppressing intraluminal vesicle formation. Furthermore,inhibition of VMP1 palmitoylation impeded small EV secretion by affecting the interaction of VMP1 with ALIX,an accessory protein of the ESCRT machinery. Taking SCs and SSCLCs as a model of intercellular communication,we discovered VMP1 palmitoylation in SCs was vital to the growth status of SSCLCs in a co-culture system. Inhibition of VMP1 palmitoylation caused low self-maintenance,increased apoptosis,and decreased proliferation rate of SSCLCs. In vivo,intraperitoneal injection of 2BP inhibited VMP1 palmitoylation and exosomal marker expression in mouse testes,which were closely associated with the level of spermatogenic cell apoptosis and proliferation.ConclusionsOur study revealed a novel mechanism for small EV secretion regulated by VMP1 palmitoylation in Sertoli cells,and demonstrated its pivotal role in intercellular communication and SSC niche.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12964-024-01529-6. View Publication

Enzymatic dissociation of human pluripotent stem cells (hPSCs) into single cells during routine passage leads to massive cell death. Although the Rho-associated protein kinase inhibitor,Y-27632 can enhance hPSC survival and proliferation at high seeding density,dissociated single cells undergo apoptosis at clonal density. This presents a major hurdle when deriving genetically modified hPSC lines since transfection and genome editing efficiencies are not satisfactory. As a result,colonies tend to contain heterogeneous mixtures of both modified and unmodified cells,making it difficult to isolate the desired clone buried within the colony. In this study,we report improved clonal expansion of hPSCs using a retinoic acid analogue,TTNPB. When combined with Y-27632,TTNPB synergistically increased hPSC cloning efficiency by more than 2 orders of magnitude (0.2% to 20%),whereas TTNPB itself increased more than double cell number expansion compared to Y-27632. Furthermore,TTNPB-treated cells showed two times higher aggregate formation and cell proliferation compared to Y-27632 in suspension culture. TTNPB-treated cells displayed a normal karyotype,pluripotency and were able to stochastically differentiate into all three germ layers both in vitro and in vivo. TTNBP acts,in part,by promoting cellular adhesion and self-renewal through the upregulation of Claudin 2 and HoxA1. By promoting clonal expansion,TTNPB provides a new approach for isolating and expanding pure hPSCs for future cell therapy applications. A retinoic acid analogue,TTNPB,improves clonal expansion in adherent and suspension culture of hPSCs by promoting cellular adhesion and self-renewal through the upregulation of Claudin 2 and HoxA1. View Publication

Statin drugs lower blood cholesterol levels for cardiovascular disease prevention. Women are more likely than men to experience adverse statin effects,particularly new-onset diabetes (NOD) and muscle weakness. Here we find that impaired glucose homeostasis and muscle weakness in statin-treated female mice are associated with reduced levels of the omega-3 fatty acid,docosahexaenoic acid (DHA),impaired redox tone,and reduced mitochondrial respiration. Statin adverse effects are prevented in females by administering fish oil as a source of DHA,by reducing dosage of the X chromosome or the Kdm5c gene,which escapes X chromosome inactivation and is normally expressed at higher levels in females than males. As seen in female mice,we find that women experience more severe reductions than men in DHA levels after statin administration,and that DHA levels are inversely correlated with glucose levels. Furthermore,induced pluripotent stem cells from women who developed NOD exhibit impaired mitochondrial function when treated with statin,whereas cells from men do not. These studies identify X chromosome dosage as a genetic risk factor for statin adverse effects and suggest DHA supplementation as a preventive co-therapy. Women are more likely than men to experience adverse statin effects,particularly new-onset diabetes and muscle weakness. Here the authors show that statin-treated female mice show reduced levels of docosahexaenoic acid (DHA) and that the adverse effects are prevented by administering fish oil as a source of DHA,by reducing dosage of the X chromosome or the Kdm5c gene. View Publication

In this study,we explore the therapeutic feasibility of globotriaosylceramide (Gb3) synthase (A4GALT)-specific siRNA-loaded polyhistidine (pHis)-incorporated lipid nanoparticles (HLNPs) for Fabry disease (FD). HLNPs were developed to deliver siRNAs targeting A4GALT using a microfluidic device,with pHis aiding in endosome escape. The therapy was tested on GLA-knockout human-induced pluripotent-stem-cell-derived endothelial cells (GLA-KO-hiPSC-ECs) and podocytes (GLA-KO-hiPSC-PCs). GLA-KO-hiPSCs-ECs or -PCs,upon differentiation,were treated with A4GALT-siRNA-HLNP. Successful intracellular uptake of A4GALT-siRNA-HLNP was confirmed through fluorescence and electron microscopy in both cell types. A4GALT-siRNA-HLNP treatment confirmed both cell types’ stability at 5 ?g/mL. Increased Gb3 deposition and zebra body formation were detected in both cell types,but A4GALT-siRNA-HLNP treatment attenuated these FD phenotypes,demonstrating reduced expression of A4GALT through western blot analysis. RNA sequencing analysis revealed that the expression of transcripts associated with FD was restored by A4GALT-siRNA-HLNP treatment in GLA-KO-hiPSCs-ECs,whereas in GLA-KO-hiPSCs-PCs,this effect was relatively less pronounced. Suppression of A4GALT via siRNA/HLNP treatment significantly rescued FD phenotypes especially in EC,presenting a novel therapeutic approach for FD. Graphical abstract This study highlights the therapeutic potential of A4GALT-siRNA delivered via HLNPs for Fabry disease (FD). In GLA-KO-hiPSC-derived endothelial cells and podocytes,treatment reduced Gb3 accumulation,restored transcriptomic changes,and mitigated FD phenotypes,with stronger effects in endothelial cells,supporting its promise as a novel FD therapy. View Publication

Alcohol use disorder (AUD) is the most prevalent substance use disorder worldwide. Acamprosate and naltrexone are anti-craving drugs used in AUD pharmacotherapy. However,molecular mechanisms underlying their anti-craving effect remain unclear. This study utilized a patient-derived induced pluripotent stem cell (iPSC)-based model system and anti-craving drugs that are used to treat AUD as “molecular probes” to identify possible mechanisms associated with alcohol craving. We examined the pathophysiology of craving and anti-craving drugs by performing functional genomics studies using iPSC-derived astrocytes and next-generation sequencing. Specifically,RNA sequencing performed using peripheral blood mononuclear cells from AUD patients with extreme values for alcohol craving intensity prior to treatment showed that inflammation-related pathways were highly associated with alcohol cravings. We then performed a genome-wide assessment of chromatin accessibility and gene expression profiles of induced iPSC-derived astrocytes in response to ethanol or anti-craving drugs. Those experiments identified drug-dependent epigenomic signatures,with IRF3 as the most significantly enriched motif in chromatin accessible regions. Furthermore,the activation of IRF3 was associated with ethanol-induced endoplasmic reticulum (ER) stress which could be attenuated by anti-craving drugs,suggesting that ER stress attenuation might be a target for anti-craving agents. In conclusion,we found that craving intensity was associated with alcohol consumption and treatment outcomes. Our functional genomic studies suggest possible relationships among craving,ER stress,IRF3 and the actions of anti-craving drugs. View Publication