技术资料

Fragile X Syndrome (FXS) is a neurological disorder caused by epigenetic silencing of the FMR1 gene. Reactivation of FMR1 is a potential therapeutic approach for FXS that would correct the root cause of the disease. Here,using a candidate-based shRNA screen,we identify nine epigenetic repressors that promote silencing of FMR1 in FXS cells (called FMR1 Silencing Factors,or FMR1- SFs). Inhibition of FMR1-SFs with shRNAs or small molecules reactivates FMR1 in cultured undifferentiated induced pluripotent stem cells,neural progenitor cells (NPCs) and post-mitotic neurons derived from FXS patients. One of the FMR1-SFs is the histone methyltransferase EZH2,for which an FDA-approved small molecule inhibitor,EPZ6438 (also known as tazemetostat),is available. We show that EPZ6438 substantially corrects the characteristic molecular and electrophysiological abnormalities of cultured FXS neurons. Unfortunately,EZH2 inhibitors do not efficiently cross the blood-brain barrier,limiting their therapeutic use for FXS. Recently,antisense oligonucleotide (ASO)-based approaches have been developed as effective treatment options for certain central nervous system disorders. We therefore derived efficacious ASOs targeting EZH2 and demonstrate that they reactivate FMR1 expression and correct molecular and electrophysiological abnormalities in cultured FXS neurons,and reactivate FMR1 expression in human FXS NPCs engrafted within the brains of mice. Collectively,our results establish EZH2 inhibition in general,and EZH2 ASOs in particular,as a therapeutic approach for FXS. View Publication

In mammals,early embryonic gastrulation process is high energy demanding. Previous studies showed that,unlike endoderm and mesoderm cells,neuroectoderm differentiated from human embryonic stem cells relied on aerobic glycolysis as the major energy metabolic process,which generates lactate as the final product. Here we explored the function of intracellular lactate during neuroectoderm differentiation. Our results revealed that the intracellular lactate level was elevated in neuroectoderm and exogenous lactate could further promote hESCs differentiation towards neuroectoderm. Changing intracellular lactate levels by sodium lactate or LDHA inhibitors had no obvious effect on BMP or WNT/?-catenin signaling during neuroectoderm differentiation. Notably,histone lactylation,especially H3K18 lactylation was significant upregulated during this process. We further performed CUT&Tag experiments and the results showed that H3K18la is highly enriched at gene promoter regions. By analyzing data from CUT&Tag and RNA-seq experiments,we further identified that four genes,including PAX6,were transcriptionally upregulated by lactate during neuroectoderm differentiation. A H3K18la modification site at PAX6 promoter was verified and exogenous lactate could also rescue the level of PAX6 after shPAX6 inhibition.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00018-024-05510-x. View Publication

Pancreatic islets are densely packed cellular aggregates containing various hormonal cell types essential for blood glucose regulation. Interactions among these cells markedly affect the glucoregulatory functions of islets along with the surrounding niche and pancreatic tissue-specific geometrical organization. However,stem cell (SC)-derived islets generated in vitro often lack the three-dimensional extracellular microenvironment and peri-vasculature,which leads to the immaturity of SC-derived islets,reducing their ability to detect glucose fluctuations and insulin release. Here,we bioengineer the in vivo-like pancreatic niches by optimizing the combination of pancreatic tissue-specific extracellular matrix and basement membrane proteins and utilizing bioprinting-based geometrical guidance to recreate the spatial pattern of islet peripheries. The bioprinted islet-specific niche promotes coordinated interactions between islets and vasculature,supporting structural and functional features resembling native islets. Our strategy not only improves SC-derived islet functionality but also offers significant potential for advancing research on islet development,maturation,and diabetic disease modeling,with future implications for translational applications. The glucoregulatory functions of pancreatic islets are affected by their surrounding niche and spatial organization. Here,bioengineered stem-cell derived islet niches use bioprinting-based geometrical guidance to promote islet maturation for improved functionality and diabetes research. View Publication

Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant neurodegenerative disease caused by repeat expansion of the CAG trinucleotide within exon 10 of the ATXN3 gene. This mutation results in the production of an abnormal ataxin-3 protein containing an extended polyglutamine tract,referred to as mutant ataxin-3. In this study,we investigated the therapeutic potential of CRISPR/Cas9-mediated genome editing for SCA3. First,we designed a specific single-guide RNA targeting the ATXN3 gene and constructed the corresponding targeting vector. Induced pluripotent stem cells (iPSCs) derived from a SCA3 patient were then electroporated with the CRISPR/Cas9 components. Positive clones were screened and validated by PCR and Sanger sequencing to obtain genome-editing iPSCs (GE-iPSCs). Subsequently,the pluripotency of GE-iPSCs was confirmed,and the effects of genome editing on mutant ataxin-3 protein expression and Golgi apparatus morphology were assessed using Western blotting and immunofluorescence analyses. Our results demonstrated that targeted insertion of polyadenylation signals (PAS) upstream of the abnormal CAG repeats effectively suppressed the production of mutant ataxin-3. This intervention also reduced the formation of neuronal nuclear inclusions in differentiated neurons,restored the structural integrity of the Golgi apparatus (which exhibited a loose and enlarged morphology in SCA3 cells),and increased the expression levels of Golgi structural proteins (GM130 and GORASP2). In conclusion,our findings indicate that the targeted insertion of PAS upstream of the abnormal CAG repeats in the ATXN3 gene represents a promising therapeutic strategy for SCA3 through genome editing.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-93369-8. View Publication

Ribosome profiling,which is based on deep sequencing of ribosome footprints,has served as a powerful tool for elucidating the regulatory mechanism of protein synthesis. However,the current method has substantial issues: contamination by rRNAs and the lack of appropriate methods to measure ribosome numbers in transcripts. Here,we overcome these hurdles through the development of “Ribo-FilterOut”,which is based on the separation of footprints from ribosome subunits by ultrafiltration,and “Ribo-Calibration”,which relies on external spike-ins of stoichiometrically defined mRNA-ribosome complexes. A combination of these approaches estimates the number of ribosomes on a transcript,the translation initiation rate,and the overall number of translation events before its decay,all in a genome-wide manner. Moreover,our method reveals the allocation of ribosomes under heat shock stress,during aging,and across cell types. Our strategy of modified ribosome profiling measures kinetic and stoichiometric parameters of cellular translation across the transcriptome. Ribosome profiling faces issues with rRNA contamination and measurements of ribosome numbers on transcripts. Here,the authors develop Ribo-FilterOut and Ribo-Calibration,methods which can be used to estimate kinetic and stoichiometric parameters of translation under various conditions. View Publication

BackgroundCHD7 encodes an ATP-dependent chromodomain helicase DNA binding protein; mutations in this gene lead to multiple developmental disorders,including CHARGE (Coloboma,Heart defects,Atresia of the choanae,Retardation of growth and development,Genital hypoplasia,and Ear anomalies) syndrome. How the mutations cause multiple defects remains largely unclear. Embryonic definitive endoderm (DE) generates the epithelial compartment of vital organs such as the thymus,liver,pancreas,and intestine.MethodsIn this study,we used the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technique to delete the CHD7 gene in human embryonic stem cells (hESCs) to generate CHD7 homozygous mutant (CHD7?/?),heterozygous mutant (CHD7+/?),and control wild-type (CHD7+/+) cells. We then investigated the ability of the hESCs to develop into DE and the other two germ layers,mesoderm and ectoderm in vitro. We also compared global gene expression and chromatin accessibility among the hESC-DE cells by RNA sequencing (RNA-seq) and the assay for transposase-accessible chromatin with sequencing (ATAC-seq).ResultsWe found that deletion of CHD7 led to reduced capacity to develop into DE and mesoderm in a dose-dependent manner. Loss of CHD7 led to significant changes in the expression and chromatin accessibility of genes associated with several pathways. We identified 40 genes that were highly down-regulated in both the expression and chromatin accessibility in CHD7 deleted hESC-DE cells.ConclusionsCHD7 is critical for DE and mesodermal development from hESCs. Our results provide new insights into the mechanisms by which CHD7 mutations cause multiple congenital anomalies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04437-9. View Publication

The immune-modulatory effects of mesenchymal stromal cells (MSCs) are widely used to treat inflammatory disorders,with indoleamine 2,4-dioxygenase-1 (IDO-1) playing a pivotal role in suppressing stimulated T-cell proliferation. Taking that three-dimensional (3D) cultures enhance MSCs’ anti-inflammatory properties compared with two-dimensional (2D) cultures,the differentially expressed miRNAs were examined. Thus,we identified hsa-miR-4662a-5p (miR-4662a) as a key inducer of IDO-1 via its suppression of bridging integrator-1 (BIN-1),a negative regulator of the IDO-1 gene. The IDO-1-inducing potential of miR-4662a was conserved across primary MSCs from various donors and sources but exhibited variability. Notably,iPSC-derived MSCs (iMSCs) demonstrated superior IDO-1 induction and immune-modulatory efficacy compared with their donor-matched primary MSCs. Accordingly,iMSCs expressing miR-4662a (4662a/iMSC) exhibited stronger suppressive effects on T-cell proliferation and more potent suppressive effects on graft-versus-host disease (GVHD),improving survival rates and reducing tissue damage in the liver and gut. Our results point to the therapeutic potential of standardized,off-the-shelf 4662a/iMSC as a robust immune-modulating cell therapy for GVHD. View Publication

Dystrophy-associated fer-1-like protein (dysferlin) conducts plasma membrane repair. Mutations in the DYSF gene cause a panoply of genetic muscular dystrophies. We targeted a frequent loss-of-function,DYSF exon 44,founder frameshift mutation with mRNA-mediated delivery of SpCas9 in combination with a mutation-specific sgRNA to primary muscle stem cells from two homozygous patients. We observed a consistent >60% exon 44 re-framing,rescuing a full-length and functional dysferlin protein. A new mouse model harboring a humanized Dysf exon 44 with the founder mutation,hEx44mut,recapitulates the patients’ phenotype and an identical re-framing outcome in primary muscle stem cells. Finally,gene-edited murine primary muscle stem-cells are able to regenerate muscle and rescue dysferlin when transplanted back into hEx44mut hosts. These findings are the first to show that a CRISPR-mediated therapy can ameliorate dysferlin deficiency. We suggest that gene-edited primary muscle stem cells could exhibit utility,not only in treating dysferlin deficiency syndromes,but also perhaps other forms of muscular dystrophy. Dysferlin-deficient muscular dystrophy is a devastating and untreatable disease. Using Cas9,the authors restored dysferlin in muscle stem cells from patients ex vivo and show proof-of-concept for autologous cell replacement therapies in a new humanized mouse model. View Publication

Patient specific induced pluripotent stem cells (iPSCs) derived ? cells represent an effective means for disease modeling and autologous diabetes cell replacement therapy. In this study,an AG73-5%gelatin methacryloyl (GelMA) /2% alginate methacrylate (AlgMA) hydrogel was employed to generate pancreatic progenitor (PP) organoids and improve stem cell-derived ? (SC-?) cell differentiation protocol. The laminin-derived homolog AG73,which mimics certain cell?matrix interactions,facilitates AKT signaling pathway activation to promote PDX1+/NKX6.1+ PP organoid formation and effectively modulates subsequent epithelial–mesenchymal transition (EMT) in the endocrine lineage. The 5%GelMA/2%AlgMA hydrogel mimics the physiological stiffness of the pancreas,providing the optimal mechanical stress and spatial structure for PP organoid differentiation. The Syndecan-4 (SDC4)-ITGAV complex plays a pivotal role in the early stages of pancreatic development by facilitating the formation of SOX9+/PDX1+ bipotent PPs. Our findings demonstrate that AG73-GelMA/AlgMA hydrogel-derived SC-? cells exhibit enhanced insulin secretion and accelerated hyperglycemia reversal in vivo. This study presents a cost-effective,stable,and efficient alternative for the comprehensive 3D culture of SC-? cells in vitro by mitigating the uncertainties associated with conventional culture methods. View Publication

Familial platelet disorder with associated myeloid malignancies (FPDMM) is an autosomal dominant disease caused by heterozygous germline mutations in RUNX1. It is characterized by thrombocytopenia,platelet dysfunction,and a predisposition to hematological malignancies. Although FPDMM is a precursor for diseases involving abnormal DNA methylation,the DNA methylation status in FPDMM remains unknown,largely due to a lack of animal models and challenges in obtaining patient-derived samples. Here,using genome editing techniques,we established two lines of human induced pluripotent stem cells (iPSCs) with different FPDMM-mimicking heterozygous RUNX1 mutations. These iPSCs showed defective differentiation of hematopoietic progenitor cells (HPCs) and megakaryocytes (Mks),consistent with FPDMM. The FPDMM-mimicking HPCs showed DNA methylation patterns distinct from those of wild-type HPCs,with hypermethylated regions showing the enrichment of ETS transcription factor (TF) motifs. We found that the expression of FLI1,an ETS family member,was significantly downregulated in FPDMM-mimicking HPCs with a RUNX1 transactivation domain (TAD) mutation. We demonstrated that FLI1 promoted binding-site-directed DNA demethylation,and that overexpression of FLI1 restored their megakaryocytic differentiation efficiency and hypermethylation status. These findings suggest that FLI1 plays a crucial role in regulating DNA methylation and correcting defective megakaryocytic differentiation in FPDMM-mimicking HPCs with a RUNX1 TAD mutation. View Publication