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Brain tumors are commonly treated with radiotherapy,but the efficacy of the treatment is limited by its toxicity to the normal tissue including post-irradiation contrast enhanced lesions often linked to necrosis. The poorly understood mechanisms behind such brain lesions were studied using cerebral organoids. Here we show that irradiation of such organoids leads to dose-dependent growth retardation and formation of liquid-filled cavities but is not correlated with necrosis. Instead,the radiation-induced changes comprise of an enhancement of cortical hem markers,altered neuroepithelial stem cell differentiation,and an increase of ZO1+/AQP1+/CLDN3+-choroid plexus (CP)-like structures accompanied by an upregulation of IGF2 mRNA,known to be expressed in CP and cerebrospinal fluid. The altered differentiation is attributed to changes in the WNT/BMP signaling pathways. We conclude that aberrant CP formation can be involved in radiation-induced brain lesions providing additional strategies for possible countermeasures. Human cerebral organoids provide insights into mechanisms behind the formation of choroid plexus (CP)-like structures that may contribute to radiation-induced brain image changes. View Publication

IntroductionDual specificity protein phosphatase 6 (DUSP6) was recently identified as a key hub gene in a causal VGF gene network that regulates late-onset Alzheimer’s disease (AD). Importantly,decreased DUSP6 levels are correlated with an increased clinical dementia rating (CDR) in human subjects,and DUSP6 levels are additionally decreased in the 5xFAD amyloidopathy mouse model.MethodsTo investigate the role of DUSP6 in AD,we stereotactically injected AAV5-DUSP6 or AAV5-GFP (control) into the dorsal hippocampus (dHc) of both female and male 5xFAD or wild type mice,to induce overexpression of DUSP6 or GFP.ResultsBarnes maze testing indicated that DUSP6 overexpression in the dHc of 5xFAD mice improved memory deficits and was associated with reduced amyloid plaque load,Aß1–40 and Aß1–42 levels,and amyloid precursor protein processing enzyme BACE1,in male but not in female mice. Microglial activation,which was increased in 5xFAD mice,was significantly reduced by dHc DUSP6 overexpression in both males and females,as was the number of “microglial clusters,” which correlated with reduced amyloid plaque size. Transcriptomic profiling of female 5xFAD hippocampus revealed upregulation of inflammatory and extracellular signal-regulated kinase pathways,while dHc DUSP6 overexpression in female 5xFAD mice downregulated a subset of genes in these pathways. Gene ontology analysis of DEGs (p < 0.05) identified a greater number of synaptic pathways that were regulated by DUSP6 overexpression in male compared to female 5xFAD.DiscussionIn summary,DUSP6 overexpression in dHc reduced amyloid deposition and memory deficits in male but not female 5xFAD mice,whereas reduced neuroinflammation and microglial activation were observed in both males and females,suggesting that DUSP6-induced reduction of microglial activation did not contribute to sex-dependent improvement in memory deficits. The sex-dependent regulation of synaptic pathways by DUSP6 overexpression,however,correlated with the improvement of spatial memory deficits in male but not female 5xFAD. View Publication

BackgroundELMSAN1 (ELM2?SANT domain?containing scaffolding protein 1) is a newly identified scaffolding protein of the MiDAC (mitotic deacetylase complex),playing a pivotal role in early embryonic development. Studies on Elmsan1 knockout mice showed that its absence results in embryo lethality and heart malformation. However,the precise function of ELMSAN1 in heart development and formation remains elusive. To study its potential role in cardiac lineage,we employed human?induced pluripotent stem cells (hiPSCs) to model early cardiogenesis and investigated the function of ELMSAN1.Methods and ResultsWe generated ELMSAN1?deficient hiPSCs through knockdown and knockout techniques. During cardiac differentiation,ELMSAN1 depletion inhibited pluripotency deactivation,decreased the expression of cardiac?specific markers,and reduced differentiation efficiency. The impaired expression of genes associated with contractile sarcomere structure,calcium handling,and ion channels was also noted in ELMSAN1?deficient cardiomyocytes derived from hiPSCs. Additionally,through a series of structural and functional assessments,we found that ELMSAN1?null hiPSC cardiomyocytes are immature,exhibiting incomplete sarcomere Z?line structure,decreased calcium handling,and impaired electrophysiological properties. Of note,we found that the cardiac?specific role of ELMSAN1 is likely associated with histone H3K27 acetylation level. The transcriptome analysis provided additional insights,indicating maturation reduction with the energy metabolism switch and restored cell proliferation in ELMSAN1 knockout cardiomyocytes.ConclusionsIn this study,we address the significance of the direct involvement of ELMSAN1 in the differentiation and maturation of hiPSC cardiomyocytes. We first report the impact of ELMSAN1 on multiple aspects of hiPSC cardiomyocyte generation,including cardiac differentiation,sarcomere formation,calcium handling,electrophysiological maturation,and proliferation. View Publication

SummaryGABAergic interneurons are inhibitory neurons of the CNS,playing a fundamental role in neural circuitry and activity. Here,we provide a robust protocol for the successful enrichment of human cerebellar GABAergic interneurons from human induced pluripotent stem cells (iPSCs) and measuring intracellular calcium transients. We describe in detail steps for culturing iPSCs; generating embryoid bodies; and differentiating and enriching for cerebellar GABAergic neurons (cGNs),with precise steps for their molecular characterization. We then detail the procedure for adeno-associated virus-mediated transduction of cGNs with genetically encoded calcium indicators,followed by intracellular calcium imaging and analyses.For complete details on the use and execution of this protocol,please refer to Pilotto et al.1 Graphical abstract Highlights•Steps described for generating GABAergic neurons from human iPSCs•Instructions for the enrichment of cerebellar GABAergic interneurons (cGNs)•Guide to calcium imaging of cGNs using genetically encoded calcium indicators Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. GABAergic interneurons are inhibitory neurons of the CNS,playing a fundamental role in neural circuitry and activity. Here,we provide a robust protocol for the successful enrichment of human-cerebellar GABAergic interneurons from human induced pluripotent stem cells (iPSCs) and measuring intracellular calcium transients. We describe in detail steps for culturing iPSCs,and generating embryoid bodies,differentiating and enriching for cerebellar GABAergic neurons (cGNs),with precise steps for their molecular characterization. We then detail the procedure for adeno-associated virus-mediated transduction of cGNs with genetically encoded calcium indicators,followed by intracellular calcium imaging and analyses. View Publication

Genomic imprinting controls parental allele-specific gene expression via epigenetic mechanisms. Abnormal imprinting at the GNAS gene causes multiple phenotypes,including pseudohypoparathyroidism type-1B (PHP1B),a disorder of multihormone resistance. Microdeletions affecting the neighboring STX16 gene ablate an imprinting control region (STX16-ICR) of GNAS and lead to PHP1B upon maternal but not paternal inheritance. Mechanisms behind this imprinted inheritance mode remain unknown. Here,we show that the STX16-ICR forms different chromatin conformations with each GNAS parental allele and enhances two GNAS promoters in human embryonic stem cells. When these cells differentiate toward proximal renal tubule cells,STX16-ICR loses its effect,accompanied by a transition to a somatic cell-specific GNAS imprinting status. The activity of STX16-ICR depends on an OCT4 motif,whose disruption impacts transcript levels differentially on each allele. Therefore,a biallelically active embryonic enhancer dictates GNAS imprinting via different chromatin conformations,underlying the allele-specific pathogenicity of STX16-ICR microdeletions. STX16 microdeletions cause pseudohypoparathyroidism type-1B only on the maternal allele. Here,the authors show that the allele-specific pathogenicity reflects differential conformations of a biallelically active enhancer dictating GNAS imprinting. View Publication

Pluripotent stem cells possess a unique nuclear architecture characterized by a larger nucleus and more open chromatin,which underpins their ability to self-renew and differentiate. Here,we show that the nucleolus-specific RNA helicase DDX18 is essential for maintaining the pluripotency of human embryonic stem cells. Using techniques such as Hi-C,DNA/RNA-FISH,and biomolecular condensate analysis,we demonstrate that DDX18 regulates nucleolus phase separation and nuclear organization by interacting with NPM1 in the granular nucleolar component,driven by specific nucleolar RNAs. Loss of DDX18 disrupts nucleolar substructures,impairing centromere clustering and perinucleolar heterochromatin (PNH) formation. To probe this further,we develop NoCasDrop,a tool enabling precise nucleolar targeting and controlled liquid condensation,which restores centromere clustering and PNH integrity while modulating developmental gene expression. This study reveals how nucleolar phase separation dynamics govern chromatin organization and cell fate,offering fresh insights into the molecular regulation of stem cell pluripotency. Pluripotent stem cells depend on specialized nuclear organization for their function. Here,the authors show that DDX18 regulates nucleolar phase separation and chromatin architecture to preserve human embryonic stem cell pluripotency. View Publication

Better understanding of the earliest molecular pathologies of all neurodegenerative diseases is expected to improve human therapeutics. We investigated the earliest molecular pathology of spinocerebellar ataxia type 1 (SCA1),a rare familial neurodegenerative disease that primarily induces death and dysfunction of cerebellum Purkinje cells. Extensive prior studies have identified involvement of transcription or RNA-splicing factors in the molecular pathology of SCA1. However,the regulatory network of SCA1 pathology,especially central regulators of the earliest developmental stages and inflammatory events,remains incompletely understood. Here,we elucidated the earliest developmental pathology of SCA1 using originally developed dynamic molecular network analyses of sequentially acquired RNA-seq data during differentiation of SCA1 patient-derived induced pluripotent stem cells (iPSCs) to Purkinje cells. Dynamic molecular network analysis implicated histone genes and cytokine-relevant immune response genes at the earliest stages of development,and revealed relevance of ISG15 to the following degradation and accumulation of mutant ataxin-1 in Purkinje cells of SCA1 model mice and human patients. Molecular changes in neurodegeneration occur much earlier than previously expected. In this study,dynamic molecular network analysis of iPSC differentiation uncovers a temporal pathway from histone to ISG15 with the earliest molecular changes of SCA1. View Publication

BackgroundChronic ischemic limb disease often leads to amputation,which remains a significant clinical problem. Smooth-muscle cells (SMCs) are crucially involved in the development and progression of many cardiovascular diseases,but studies with primary human SMCs have been limited by a lack of availability. Here,we evaluated the efficiency of two novel protocols for differentiating human induced-pluripotent stem cells (hiPSCs) into SMCs and assessed their potency for the treatment of ischemic limb disease.MethodshiPSCs were differentiated into SMCs via a conventional two-dimensional (2D) protocol that was conducted entirely with cell monolayers,or via two protocols that consisted of an initial five-day three-dimensional (3D) spheroid phase followed by a six-day 2D monolayer phase (3D?+?2D differentiation). The 3D phases were conducted in shaker flasks on an orbital shaker (the 3D?+?2D shaker protocol) or in a PBS bioreactor (the 3D?+?2D bioreactor protocol). Differentiation efficiency was evaluated via the expression of SMC markers (smooth-muscle actin [SMA],smooth muscle protein 22 [SM22],and Calponin-1),and the biological activity of the differentiated hiPSC-SMCs was evaluated via in-vitro assessments of migration (scratch assay),contraction in response to the treatment with a prostaglandin H2 analog (U46619),and tube formation on Geltrex,as well as in-vivo measurements of perfusion (fluorescence angiography) and vessel density in the limbs of mice that were treated with hiPSC-SMCs after experimentally induced hind-limb ischemia (HLI).ResultsBoth 3D?+?2D protocols yielded?>?5.6?×?107 hiPSC-SMCs/differentiation,which was?~?nine-fold more than that produced via 2D differentiation,and flow cytometry analyses confirmed that?>?98% of the 3D?+?2D-differentiated hiPSC-SMCs expressed SMA,?>?81% expressed SM22,and?>?89% expressed Calponin-1. hiPSC-SMCs obtained via the 3D?+?2D shaker protocol also displayed typical SMC-like migratory,contraction,and tube-formation activity in-vitro and significantly improved measurements of perfusion,vessel density,and SMA-positive arterial density in the ischemic limb of mouse HLI model.ConclusionsOur dynamic 3D?+?2D protocols produced an exceptionally high yield of hiPSC-SMCs. Transplantation of these hiPSC-SMCs results in significantly improved recovery of ischemic limb after ischemic injury in mice. View Publication

IntroductionNeutrophils are highly abundant innate immune cells that are constantly produced from myeloid progenitors in the bone marrow. Differentiated neutrophils can perform an arsenal of effector functions critical for host defense. This study aims to quantitatively understand neutrophil mitochondrial metabolism throughout differentiation and activation,and to elucidate the impact of mitochondrial metabolism on neutrophil functions.MethodsTo study metabolic remodeling throughout neutrophil differentiation,murine ER-Hoxb8 myeloid progenitor-derived neutrophils and human induced pluripotent stem cell-derived neutrophils were assessed as models. To study the metabolic remodeling upon neutrophil activation,differentiated ER-Hoxb8 neutrophils and primary human neutrophils were activated with various stimuli,including ionomycin,monosodium urate crystals,and phorbol 12-myristate 13-acetate. Characterization of cellular metabolism by isotopic tracing,extracellular flux analysis,metabolomics,and fluorescence-lifetime imaging microscopy revealed dynamic changes in mitochondrial metabolism.ResultsAs neutrophils mature,mitochondrial metabolism decreases drastically,energy production is offloaded from oxidative phosphorylation,and glucose oxidation through the TCA cycle is substantially reduced. Nonetheless,mature neutrophils retain the capacity for mitochondrial metabolism. Upon stimulation with certain stimuli,TCA cycle is rapidly activated. Mitochondrial pyruvate carrier inhibitors reduce this re-activation of the TCA cycle and inhibit the release of neutrophil extracellular traps. Treatment with these inhibitors also impacts neutrophil redox status,migration,and apoptosis without significantly changing overall bioenergetics.ConclusionsTogether,these results demonstrate that mitochondrial metabolism is dynamically remodeled and plays a significant role in neutrophils. Furthermore,these findings point to the therapeutic potential of mitochondrial pyruvate carrier inhibitors in a range of conditions where dysregulated neutrophil response drives inflammation and contributes to pathology. View Publication

BackgroundRNA-binding proteins (RBPs) are essential in cardiac development. However,a large of them have not been characterized during the process.MethodsWe applied the human embryonic stem cells (hESCs) differentiated into cardiomyocytes model and constructed SAMD4A-knockdown/overexpression hESCs to investigate the role of SAMD4A in cardiomyocyte lineage specification.ResultsSAMD4A,an RBP,exhibits increased expression during early heart development. Suppression of SAMD4A inhibits the proliferation of hESCs,impedes cardiac mesoderm differentiation,and impairs the function of hESC-derived cardiomyocytes. Correspondingly,forced expression of SAMD4A enhances proliferation and promotes cardiomyogenesis. Mechanistically,SAMD4A specifically binds to FGF2 via a specific CNGG/CNGGN motif,stabilizing its mRNA and enhancing translation,thereby upregulating FGF2 expression,which subsequently modulates the AKT signaling pathway and regulates cardiomyocyte lineage differentiation. Additionally,supplementation of FGF2 can rescue the proliferation defect of hESCs in the absence of SAMD4A.ConclusionsOur study demonstrates that SAMD4A orchestrates cardiomyocyte lineage commitment through the post-transcriptional regulation of FGF2 and modulation of AKT signaling. These findings not only underscore the essential role of SAMD4A in cardiac organogenesis,but also provide critical insights into the molecular mechanisms underlying heart development,thereby informing potential therapeutic strategies for congenital heart disease.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04269-7. View Publication

Autosomal dominant polycystic kidney disease (ADPKD) is the most common renal genetic disease,with most patients carrying mutations in PKD1. The main feature is the formation of bilateral renal cysts,leading to end stage renal failure in a significant proportion of those affected. Despite recent advances made in understanding ADPKD,there are currently no effective curative therapies. The emergence of human induced pluripotent stem cell (hiPSC)-derived kidney disease models has led to renewed hope that more physiological systems will allow for the development of novel treatments. hiPSC-derived organoid models have been used to recapitulate ADPKD,however they present numerous limitations which remain to be addressed. In the present study,we report an efficient method for generating organoids containing a network of polarised and ciliated epithelial tubules. PKD1 null (PKD1?/?) organoids spontaneously develop dilated tubules,recapitulating early ADPKD cystogenesis. Furthermore,PKD1?/? tubules present primary cilia defects when dilated. Our model could therefore serve as a valuable tool to study early ADPKD cystogenesis and to develop novel therapies.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-94855-9. View Publication

Organoids are self-assembled 3D cellular structures that resemble organs structurally and functionally,providing in vitro platforms for molecular and therapeutic studies. Generation of organoids from human cells often requires long and costly procedures with arguably low efficiency. Prediction and selection of cellular aggregates that result in healthy and functional organoids can be achieved by using artificial intelligence-based tools. Transforming images of 3D cellular constructs into digitally processable data sets for training deep learning models requires labeling of morphological boundaries,which often is performed manually. Here,we report an application named OrganoLabeler,which can create large image-based data sets in a consistent,reliable,fast,and user-friendly manner. OrganoLabeler can create segmented versions of images with combinations of contrast adjusting,K-means clustering,CLAHE,binary,and Otsu thresholding methods. We created embryoid body and brain organoid data sets,of which segmented images were manually created by human researchers and compared with OrganoLabeler. Validation is performed by training U-Net models,which are deep learning models specialized in image segmentation. U-Net models,which are trained with images segmented by OrganoLabeler,achieved similar or better segmentation accuracies than the ones trained with manually labeled reference images. OrganoLabeler can replace manual labeling,providing faster and more accurate results for organoid research free of charge. View Publication