技术资料

Sac1 is a conserved phosphoinositide phosphatase,whose loss-of-function compromises cell and organism viability. Here,we employ acute auxin-inducible Sac1 degradation to identify its immediate downstream effectors in human cells. Most of Sac1 is degraded in ~1 h,paralleled by increased PI(4)P and decreased cholesterol in the trans-Golgi network (TGN) during the following hour,and superseded by Golgi fragmentation,impaired glycosylation,and selective degradation of TGN proteins by ~4 h. The TGN disintegration results from its acute deacidification caused by disassembly of the Golgi V-ATPase. Mechanistically,Sac1 mediated TGN membrane composition maintains an assembly-promoting conformation of the V0a2 subunit. Key phenotypes of acute Sac1 degradation are recapitulated in human differentiated trophoblasts,causing processing defects of chorionic gonadotropin,in line with loss-of-function intolerance of the human SACM1L gene. Collectively,our findings reveal that the assembly of the Golgi V-ATPase is controlled by the TGN membrane via Sac1 fuelled lipid exchange. This study employs auxin-inducible degradation of Sac1. The authors reveal that acute Sac1 depletion changes the Golgi membrane lipid composition,causing disassembly of the Golgi V-ATPase and eventually resulting in cargo processing defects. View Publication

The aim of this study is to establish an in vitro co-culture system to model allograft rejection using kidney organoids system derived from human induced pluripotent stem cells (hiPSCs). We co-cultured kidney organoids derived from wild-type hiPSCs with HLA-mismatched peripheral blood mononuclear cells (PBMCs) from healthy controls (HC) for 24 h. To assess allogeneic rejection modeling,we measured the expression of HLA molecules,(HLA-ABC and HLA-DR),and evaluated cellular damage in the kidney organoids. Additionally,we analyzed the distribution of T cells and their subsets within the co-cultured PBMCs. The immunosuppressive effect of tacrolimus was also evaluated in this co-culture system. Transcriptomic analysis,conducted using RNA sequencing,identified molecules associated with allogeneic rejection. When kidney organoids were co-cultured with alloreactive PBMCs for 24 h,HLA-ABC and HLA-DR expression significantly increased in kidney organoid cells. Additionally,kidney organoids showed reduced cell viability and increased apoptosis compared to syngeneic controls,as assessed by flow cytometry and Annexin V/PI staining. However,treatment with tacrolimus reduced HLA expression in a dose-dependent manner,highlighting the diminished alloimmune responses. Further analysis of PBMC subsets revealed shifts in T helper (TH) and cytotoxic T cell (TC) populations under allogeneic conditions,including increased effector TH and TC cells. Transcriptomic analysis through RNA sequencing identified 256 differentially expressed genes (DEGs),with notable immune-related pathways such as NF-kappa B and TNF signaling involved in allograft rejection. These results provide evidence that a co-culture system with allogeneic kidney organoids and PBMCs can potentially model transplant rejection in vitro.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00018-025-05867-7. View Publication

Immune rejection is one of the most serious challenges in allogeneic transplantation,including allogeneic induced pluripotent stem cell (allo-iPSC)-derived cell therapy. Beta-2-Microglobulin gene-knockout,human leukocyte antigen (HLA) class I-deficient iPSCs can evade immune rejection by host T cells,which occurs due to HLA mismatches. However,natural killer (NK) cells recognize HLA class Ⅰ-deficient cells and reject them,which is known as the missing-self response. Introducing chimeric HLA-E protein to HLA class Ⅰ-deficient iPSCs suppresses the missing-self response of NK cells expressing the inhibitory receptor NKG2A; however,technology to suppress NKG2A-negative NK cells is still required. Here,we developed novel agonists for the other inhibitory receptor,killer immunoglobulin receptor (KIR),on NK cells. We found that antibodies that bind to activating KIR enhance NK cell activation and developed selective agonists for inhibitory KIRs (KIR2DL1,KIR2DL2/3,and KIR3DL1). Introducing these selective inhibitory KIR agonists on T cells and HLA class Ⅰ-deficient iPSCs allowed them to evade immune rejection by NK cells. Additionally,we identified an NKG2A-selective agonist as an alternative to chimeric HLA-E,which stimulates the activating receptor NKG2C. This technology enhances immune tolerance in allo-iPSCs and facilitates the development of various iPSC-derived regenerative medicines. The online version contains supplementary material available at 10.1038/s41598-025-18394-z. Subject terms: Allotransplantation,NK cells View Publication

Alzheimer's disease (AD) is characterized by tau pathology,leading to neurodegeneration. Astrocytes regulate central nervous system homeostasis and influence AD progression. The APOE3‐Christchurch (APOE3‐Ch) variant is linked to AD resilience,but its protective mechanisms remain unclear. Human induced pluripotent stem cell–derived astrocytes (APOE3‐Ch and wild type) were used to assess tau uptake,clearance,lipid metabolism,and transcriptomic adaptations. Fluorescently labeled 2N4R‐P301L tau oligomers were tracked,and pathway‐specific inhibitors dissected tau clearance mechanisms. Lipidomic and transcriptomic analyses were performed to identify genotype‐specific adaptations. APOE3‐Ch astrocytes exhibited enhanced tau uptake via heparan sulfate proteoglycan‐ and lipoprotein receptor‐related protein 1‐mediated pathways and superior clearance through lysosomal and proteasomal degradation. They exported less tau,limiting propagation. Transcriptomic analyses revealed upregulation of genes involved in cell projection assembly and endocytosis. Lipidomic profiling showed reduced ceramides and gamma‐linolenic acid,linked to decreased neuroinflammation and ferroptosis. APOE3‐Ch astrocytes promote tau clearance and metabolic adaptations,providing insights into genetic resilience in AD and potential therapeutic targets. APOE3‐Christchurch (APOE3‐Ch) astrocytes exhibit significantly increased tau internalization compared to wild‐type astrocytes,facilitated by upregulated heparan sulfate proteoglycan and low‐density lipoprotein receptor‐related protein 1 pathways. APOE3‐Ch astrocytes demonstrate more efficient tau degradation via both lysosomal and proteasomal pathways,while exporting significantly less tau,potentially reducing tau propagation in the central nervous system. APOE3‐Ch astrocytes show upregulation of genes involved in cell projection assembly and endocytosis,suggesting structural and functional modifications that enhance tau processing. Lipidomic profiling reveals reduced ceramide levels and gamma‐linolenic acid downregulation in APOE3‐Ch astrocytes,alterations linked to reduced neuroinflammatory and ferroptotic activity,contributing to the protective phenotype. View Publication

Type 1 interferons (IFN-Is) exhibit significant antiviral,antitumor,and immunoregulatory properties,demonstrating substantial therapeutic potential. However,IFN-Is are pleiotropic cytokines,and the available data on their effect under specific pathological conditions are inconclusive. Furthermore,the systemic administration of IFN-Is can result in side effects. Generating cells that can migrate to the pathological focus and provide regulated local production of IFN-Is could overcome this limitation and provide a model for an in-depth analysis of the biological and therapeutic effects of IFN-Is. Induced pluripotent stem cells (iPSCs) are a valuable source of various differentiated cell types,including human immune cells. In this study,we describe the generation of genetically modified human iPSCs with doxycycline-controlled overexpression of interferon β (IFNB1). Three IFNB1-overexpressing iPSC lines (IFNB-iPSCs) and one control line expressing the transactivator M2rtTA (TA-iPSCs) were generated using the CRISPR/Cas9 technology. The pluripotency of the generated cell lines has been confirmed by the following: (i) cell morphology; (ii) the expression of the pluripotency markers OCT4,SOX2,TRA 1-60,and NANOG; and (iii) the ability to spontaneously differentiate into the derivatives of the three germ layers. Upon the addition of doxycycline,all IFNB-iPSCs upregulated IFNB1 expression at RNA (depending on the iPSC line,126-816-fold) and protein levels. The IFNB-iPSCs and TA-iPSCs generated here represent a valuable cellular model for studying the effects of IFN-β on the activity and differentiation trajectories of different cell types,as well as for generating different types of cells with controllable IFN-β expression. View Publication

Seven female individuals with multiple congenital anomalies,developmental delay and/or intellectual disability have been found to have a genetic variant of uncertain significance in the mediator complex subunit 12 gene ( MED12 c.3412C>T,p.Arg1138Trp). The functional consequence of this genetic variant in disease is undetermined,and insight into disease mechanism is required. We identified a de novo MED12 p.Arg1138Trp variant in a female patient and compared disease phenotypes with six female individuals identified in the literature. To investigate affected biological pathways,we derived two induced pluripotent stem cell (iPSC) lines from the patient: one expressing wildtype MED12 and the other expressing the MED12 p.Arg1138Trp variant. We performed neural disease modelling,transcriptomics and protein analysis,comparing healthy and variant cells. When comparing the two cell lines,we identified altered gene expression in neural cells expressing the variant,including genes regulating RNA polymerase II activity,transcription,pre-mRNA processing,and neural development. We also noted a decrease in MED12L expression. Pathway analysis indicated temporal delays in axon development,forebrain differentiation,and neural cell specification with significant upregulation of pre-ribosome complex gene pathways. In a human neural model,expression of MED12 p.Arg1138Trp altered neural cell development and dysregulated the pre-ribosome complex providing functional evidence of disease aetiology and mechanism in MED12-related disorders. The online version contains supplementary material available at 10.1186/s10020-025-01365-5. View Publication

IntroductionExposure to teratogenic compounds during pregnancy can lead to significant birth defects. Given the considerable variation in drug responses across species,along with the financial and ethical challenges associated with animal testing,the development of advanced human-based in vitro assays is imperative for effectively identifying potential human teratogens. Previously,we developed a human induced pluripotent stem cells (hiPSCs)-based biomarker assay,ReproTracker,that follows the differentiation of hiPSCs into hepatocytes and cardiomyocytes. The assay combines morphological profiling with the assessment of time-dependent expression patterns of cell-specific biomarkers to detect developmental toxicity responses.MethodsTo further increase the predictability of the assay in identifying potential teratogens,we added differentiation of hiPSCs towards neural rosette-like cells. We evaluated the performance of the extended assay with a set of 51 well-known in vivo teratogens and non-teratogens,including the compounds listed in the ICH S5 reference list.ResultsThe optimized assay correctly identified (neuro)developmental toxicants that were not detected in the hepatocyte and cardiomyocyte differentiation assays. These compounds selectively downregulated gene and protein expression of the neuroectodermal marker PAX6 and/or neural rosette marker NESTIN in a concentration-dependent manner and disrupted the differentiation of hiPSCs towards neural rosette-like cells. Overall,based on the current dataset,the addition of neural commitment improved the assay accuracy (from 72.55% to 86.27%) and sensitivity (from 67.50% to 87.50%),when compared to the previously described assay.DiscussionIn summary,trilineage differentiation expanded the spectrum of teratogenic agents detectable by ReproTracker,making the assay an invaluable tool for early in vitro teratogenicity screening. View Publication

Prion diseases,such as sporadic Creutzfeldt-Jakob Disease (sCJD),are neurodegenerative disorders caused by misfolding of the prion protein (PrP). The D178N mutation in the PrP gene causes Fatal Familial Insomnia (FFI). Here we show that both sCJD and FFI prions can infect human cerebral organoids with or without the D178N mutation,and that the resulting infection is dictated by the inoculating prion and not the host organoid genotype. View Publication

Artificial skin models have emerged as valuable tools for evaluating cosmetic ingredients and developing treatments for skin regeneration. Among them,3D skin equivalent models (SKEs) using human primary skin cells are widely utilized and supported by standardized testing guidelines. However,primary cells face limitations such as restricted donor availability and challenges in conducting genotype-specific studies. To overcome these issues,recent approaches have focused on differentiating skin cells from human-induced pluripotent stem cells (hiPSCs). In this study,we developed a protocol to differentiate high-purity skin cells,such as fibroblasts (hFIBROs) and keratinocytes (hKERAs),from hiPSCs. To construct the hiPSC-derived SKE (hiPSC-SKE),a dermis was first formed by culturing a collagen and hFIBROs mixture within an insert. Subsequently,hKERAs were seeded onto the dermis,and keratinization was induced under air-liquid culture conditions to establish an epidermis. Histological analysis with hematoxylin and eosin staining confirmed that the hiPSC-SKE recapitulated the layered architecture of native human skin and expressed appropriate epidermal and dermal markers. Moreover,exposure to Triton X-100,a known skin irritant,led to marked epidermal damage and significantly reduced cell viability,validating the model’s functional responsiveness. These findings indicate that the hiPSC-SKE model represents a promising alternative for various skin-related applications,including the replacement of animal testing. View Publication

IntroductionAngelman Syndrome (AS) is characterized in large part by the loss of functional UBE3A protein in mature neurons. A majority of AS etiologies is linked to deletion of the maternal copy of the UBE3A gene and epigenetic silencing of the paternal copy. A common therapeutic strategy is to unsilence the intact paternal copy thereby restoring UBE3A levels. Identifying novel therapies has been aided by a UBE3A-YFP reporter mouse model. This study presents an analogous fluorescent UBE3A reporter system in human cells.MethodsPreviously derived induced Pluripotent Stem Cells (iPSCs) with a Class II large deletion at the UBE3A locus are used in this study. mGL and eGFP are integrated downstream of the endogenous UBE3A using CRISPR/Cas9. These reporter iPSCs are differentiated into 2D and 3D neural cultures to monitor long-term neuronal maturation. Green fluorescence dynamics are analyzed by immunostaining and flow cytometry.ResultsThe reporter is successfully integrated into the genome and reports paternal UBE3A expression. Fluorescence expression gradually reduces with UBE3A silencing in neurons as they mature. Expression patterns also reflect expected responses to molecules known to reactivate paternal UBE3A.DiscussionThis human-cell-based model can be used to screen novel therapeutic candidates,facilitate tracking of UBE3A expression in time and space,and study human-specific responses. However,its ability to restore UBE3A function cannot be studied using this model. Further research in human cells is needed to engineer systems with functional UBE3A to fully capture the therapeutic capabilities of novel candidates. View Publication