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Current protocols generate highly pure human induced pluripotent stem cell–derived cardiomyocytes (hiPSC‐CMs) in vitro that recapitulate characteristics of mature in vivo cardiomyocytes. Yet,a risk of arrhythmias exists when hiPSC‐CMs are injected into large animal models. Thus,understanding hiPSC‐CM maturational mechanisms is crucial for clinical translation. Forkhead box (FOX) transcription factors regulate postnatal cardiomyocyte maturation through a balance between FOXO and FOXM1. We also previously demonstrated that p53 activation enhances hiPSC‐CM maturation. Here,we investigate whether p53 activation modulates the FOXO/FOXM1 balance to promote hiPSC‐CM maturation in 3‐dimensional suspension culture. Three‐dimensional cultures of hiPSC‐CMs were treated with Nutlin‐3a (p53 activator,10 μM),LOM612 (FOXO relocator,5 μM),AS1842856 (FOXO inhibitor,1 μM),or RCM‐1 (FOXM1 inhibitor,1 μM),starting 2 days after onset of beating,with dimethyl sulfoxide (0.2% vehicle) as control. P53 activation promoted hiPSC‐CM metabolic and electrophysiological maturation alongside FOXO upregulation and FOXM1 downregulation,in n=3 to 6 per group for all assays. FOXO inhibition significantly decreased expression of cardiac‐specific markers such as TNNT2. In contrast,FOXO activation or FOXM1 inhibition promoted maturational characteristics such as increased contractility,oxygen consumption,and voltage peak maximum upstroke velocity,in n=3 to 6 per group for all assays. Further,by single‐cell RNA sequencing of n=2 LOM612‐treated cells compared with dimethyl sulfoxide,LOM612‐mediated FOXO activation promoted expression of cardiac maturational pathways. We show that p53 activation promotes FOXO and suppresses FOXM1 during 3‐dimensional hiPSC‐CM maturation. These results expand our understanding of hiPSC‐CM maturational mechanisms in a clinically‐relevant 3‐dimensional culture system. View Publication

Hematopoietic aging is associated with decreased hematopoietic stem cell (HSC) self-renewal capacity and myeloid skewing. We report that culture of bone marrow (BM) HSCs from aged mice with epidermal growth factor (EGF) suppressed myeloid skewing,increased multipotent colony formation,and increased HSC repopulation in primary and secondary transplantation assays. Mice transplanted with aged,EGF-treated HSCs displayed increased donor cell engraftment within BM HSCs and systemic administration of EGF to aged mice increased HSC self-renewal capacity in primary and secondary transplantation assays. Expression of a dominant negative EGFR in Scl/Tal1 + hematopoietic cells caused increased myeloid skewing and depletion of long term-HSCs in 15-month-old mice. EGF treatment decreased DNA damage in aged HSCs and shifted the transcriptome of aged HSCs from genes regulating cell death to genes involved in HSC self-renewal and DNA repair but had no effect on HSC senescence. These data suggest that EGFR signaling regulates the repopulating capacity of aged HSCs. Subject areas: Human physiology,cellular physiology,molecular medicine,stem cells research,functional aspects of cell biology View Publication

Converging evidence indicates that extra-embryonic yolk sac is the source of both macrophages and endothelial cells in adult mouse tissues. Prevailing views are that these embryonically derived cells are maintained after birth by proliferative self-renewal in their differentiated states. Here we identify clonogenic endothelial-macrophage (EndoMac) progenitor cells in the adventitia of embryonic and postnatal mouse aorta,that are independent of Flt3-mediated bone marrow hematopoiesis and derive from an early embryonic CX 3 CR1 + and CSF1R + source. These bipotent progenitors are proliferative and vasculogenic,contributing to adventitial neovascularization and formation of perfused blood vessels after transfer into ischemic tissue. We establish a regulatory role for angiotensin II,which enhances their clonogenic and differentiation properties and rapidly stimulates their proliferative expansion in vivo. Our findings demonstrate that embryonically derived EndoMac progenitors participate in local vasculogenic responses in the aortic wall by contributing to the expansion of endothelial cells and macrophages postnatally. Subject terms: Angiogenesis,Myelopoiesis,Haematopoietic stem cells View Publication

Poor graft function (PGF),characterized by myelosuppression,represents a significant challenge following allogeneic hematopoietic stem cell transplantation (allo-HSCT) with human cytomegalovirus (HCMV) being established as a risk factor for PGF. However,the underlying mechanism remains unclear. Bone marrow endothelial progenitor cells (BM-EPCs) play an important role in supporting hematopoiesis and their dysfunction contributes to PGF development. We aim to explore the effects of CMV on BM-EPCs and its underlying mechanism. We investigated the compromised functionality of EPCs derived from individuals diagnosed with HCMV viremia accompanied by PGF,as well as after infected by HCMV AD 169 strain in vitro,characterized by decreased cell proliferation,tube formation,migration and hematopoietic support,and increased apoptosis and secretion of TGF-β1. We demonstrated that HCMV-induced TGF-β1 secretion by BM-EPCs played a dominant role in hematopoiesis suppression in vitro experiment. Moreover,HCMV down-regulates Vitamin D receptor (VDR) and subsequently activates p38 MAPK pathway to promote TGF-β1 secretion by BM-EPCs. HCMV could infect BM-EPCs and lead to their dysfunction. The secretion of TGF-β1 by BM-EPCs is enhanced by CMV through the activation of p38 MAPK via a VDR-dependent mechanism,ultimately leading to compromised support for hematopoietic progenitors by BM EPCs,which May significantly contribute to the pathogenesis of PGF following allo-HSCT and provide innovative therapeutic strategies targeting PGF. View Publication

Addiction is known to occur through the consumption of substances such as pharmaceuticals,illicit drugs,food,alcohol and tobacco. These addictions can be viewed as drug addiction,resulting from the ingestion of chemical substances contained in them. Multiple neural networks,including the reward system,anti‐reward/stress system and central immune system in the brain,are believed to be involved in the onset of drug addiction. Although various compound evaluations using microelectrode array (MEA) as an in vitro testing methods to evaluate neural activities have been conducted,methods for assessing addiction have not been established. In this study,we aimed to develop an in vitro method for assessing the addiction of compounds,as an alternative to animal experiments,using human iPS cell‐derived dopaminergic neurons with MEA measurements. MEA data before and after chronic exposure revealed specific changes in addictive compounds compared to non‐addictive compounds,demonstrating the ability to estimate addiction of compound. Additionally,conducting gene expression analysis on cultured samples after the tests revealed changes in the expression levels of various receptors (nicotine,dopamine and GABA) due to chronic administration of addictive compounds,suggesting the potential interpretation of these expression changes as addiction‐like responses in MEA measurements. The addiction assessment method using MEA measurements in human iPS cell‐derived dopaminergic neurons conducted in this study proves effective in evaluating addiction of compounds on human neural networks. View Publication

Human pluripotent stem cells (hPSCs) represent a powerful model system to study early developmental processes. However,lineage specification into trophectoderm (TE) and trophoblast (TB) differentiation remains poorly understood,and access to well-characterized placental cells for biomedical research is limited,largely depending on fetal tissues or cancer cell lines. Here,we developed novel strategies enabling highly efficient TE specification that generates cytotrophoblast (CTB) and multinucleated syncytiotrophoblast (STB),followed by the establishment of trophoblast stem cells (TSCs) capable of differentiating into extravillous trophoblast (EVT) and STB after long-term expansion. We confirmed stepwise and controlled induction of lineage- and cell-type-specific genes consistent with developmental biology principles and benchmarked typical features of placental cells using morphological,biochemical,genomics,epigenomics,and single-cell analyses. Charting a well-defined roadmap from hPSCs to distinct placental phenotypes provides invaluable opportunities for studying early human development,infertility,and pregnancy-associated diseases. Subject areas: Natural sciences,Biological sciences,Cell biology,Stem cells research View Publication

The challenge of expanding haematopoietic stem/progenitor cells (HSPCs) in vitro has limited their clinical application. Human hair follicle mesenchymal stem cells (hHFMSCs) can be reprogrammed to generate intermediate stem cells by transducing OCT4 (hHFMSCs OCT4 ) and pre-inducing with FLT3LG/SCF,and differentiated into erythrocytes. These intermediate cells exhibit gene expression patterns similar to pre-HSCs,making them promising for artificial haematopoiesis. However,further investigation is required to elucidate the in vitro proliferation ability and mechanism underlying the self-renewal of pre-HSCs derived from hHFMSCs. hHFMSCs OCT4 were pre-treated with FLT3LG and SCF cytokines,followed by characterization and isolation of the floating cell subsets for erythroid differentiation through stimulation with hematopoietic cytokines and nutritional factors. Cell adhesion was assessed through disassociation and adhesion assays. OCT4 expression levels were measured using immunofluorescence staining,RT-qPCR,and Western blotting. RNA sequencing and Gene Ontology (GO) enrichment analysis were then conducted to identify proliferation-related biological processes. Proliferative capacity was evaluated through CCK-8,colony formation assays,Ki67 index,and cell cycle analysis. Cytoskeleton was observed through Wright‒Giemsa,Coomassie brilliant blue,and phalloidin staining. Expression of adherens junction (AJ) core members was confirmed through RT‒qPCR,Western blotting,and immunofluorescence staining before and after ZO-1 knockdown. A regulatory network was constructed to determine relationships among cytoskeleton,proliferation,and the AJ pathway. Student’s t tests (GraphPad Prism 8.0.2) were used for group comparisons. The results were considered significant at P < 0.05. Pre-treatment of hHFMSCs OCT4 with FLT3LG and SCF leads to the emergence of floating cell subsets exhibiting small,globoid morphology,suspended above adherent cells,forming colonies,and displaying minimal expression of CD45. Excessive OCT4 expression weakens adhesion in floating hHFMSCs OCT4 . Floating cells moderately enhanced proliferation and undergo cytoskeleton remodelling,with increased contraction and aggregation of F-actin near the nucleus. The upregulation of ZO-1 could impact the expressions of F-actin,E-cadherin,and β-catenin genes,as well as the nuclear positioning of β-catenin,leading to variations in the cytoskeleton and cell cycle. Finally,a regulatory network revealed that the AJ pathway cored with ZO-1 critically bridges cytoskeletal remodelling and haematopoiesis-related proliferation in a β-catenin-dependent manner. ZO-1 improved the self-renewal of pre-HSCs from OCT4-overexpressing hHFMSCs by remodeling the cytoskeleton via the ZO-1-regulated AJ pathway,suggesting floating hHFMSCs OCT4 as the promising seed cells for artificial hematopoiesis. The online version contains supplementary material available at 10.1186/s13287-024-04080-w. View Publication

Prime Editing can rewrite genes in living cells by allowing point mutations,deletions,or insertion of small DNA sequences with high precision. However,its safe and efficient delivery into human stem cells remains a technical challenge. In this report,we engineer Nanoscribes,virus-like particles that encapsidate ribonucleoprotein complexes of the Prime Editing system and allow their delivery into recipient cells. We identify key features that unlock the potential of Nanoscribes,including the use of multiple fusogens,the improvement of pegRNAs structures,their encoding by a Pol II system and the optimization of Prime-Editors. Nanoscribes edit HEK293T with an efficiency of 68% at the HEK3 locus with increased fidelity over DNA-transfection and support pegRNA-multiplexing. Importantly,Nanoscribes permit editing of myoblasts,hiPSCs and hiPSCs-derived hematopoietic stem cells with an editing efficiency up to 25%. Nanoscribes is an asset for development of next generation genome editing approaches using VLPs. Subject terms: CRISPR-Cas9 genome editing,Genetic vectors,Nanoparticles View Publication

Neurons derived from induced pluripotent stem cells (h-iPSC-Ns) provide an invaluable model for studying the physiological aspects of human neuronal development under healthy and pathological conditions. However,multiple studies have demonstrated that h-iPSC-Ns exhibit a high degree of functional and epigenetic diversity. Due to the imprecise characterization and significant variation among the currently available maturation protocols,it is essential to establish a set of criteria to standardize models and accurately characterize and define the developmental properties of human neurons derived from iPSCs. In this study,we conducted comprehensive cellular and network level analysis of the functional development of human neurons,generated from iPSCs obtained from healthy young female peripheral blood mononuclear cells by BDNF and GDNF treatment. We provide a thorough description of the maturation process of h-iPSC-Ns over a 10-week in vitro period using conventional whole-cell patch clamp and dynamic clamp techniques,alongside with morphometry and immunocytochemistry. Additionally,we utilized calcium imaging to monitor the progression of synaptic activity and network communication. At the single cell level,human neurons exhibited gradually decreasing membrane resistance in parallel with improved excitability. By the fifth week of maturation,firing profiles were consistent with those of mature regular firing type of neurons. At the network level,fast glutamatergic and depolarizing GABAergic synaptic connections were abundant together with synchronized network activity from the sixth week of maturation. Alterations in the expression of GABA A receptor subunits were also observed during the process of maturation. The sequence of differentiation events was consistent,providing a robust temporal framework to execute experiments at defined stages of neuronal maturation as well as to use a specific set of experiments to assess a culture’s maturation. The uncovered progression of differentiation events provides a powerful tool to aid the planning and designing of targeted experiments during defined stages of neuronal maturation. View Publication

The manufacturing of allogeneic cell therapeutics based on human-induced pluripotent stem cells (hiPSCs) holds considerable potential to revolutionize the accessibility and affordability of modern healthcare. However,achieving the cell yields necessary to ensure robust production hinges on identifying suitable and scalable single-use (SU) bioreactor systems. While specific stirred SU bioreactor types have demonstrated proficiency in supporting hiPSC expansion at L -scale,others,notably instrumented SU multiplate and fixed-bed bioreactors,remain relatively unexplored. By characterizing these bioreactors using both computational fluid dynamics and experimental bioengineering methods,operating ranges were identified for the Xpansion ® 10 and Ascent™ 1 m 2 bioreactors in which satisfactory hiPSC expansion under serum-free conditions was achieved. These operating ranges were shown not only to effectively limit cell exposure to wall shear stress but also facilitated sufficient oxygen transfer and mixing. Through their application,almost 5 × 10 9 viable cells could be produced within 5 days,achieving expansion factors of up to 35 without discernable impact on cell viability,identity,or differentiation potential. Key Points • Bioengineering characterizations allowed the identification of operating ranges that supported satisfactory hiPSC expansion • Both the Xpansion ® 10 multiplate and Ascent™ 1 m 2 fixed-bed reactor accommodated the production of almost 5 × 10 9 viable cells within 5 days • Exposing the hiPSCs to a median wall shear stress of up to 8.2 × 10 −5 N cm −2 did not impair quality The online version contains supplementary material available at 10.1007/s00253-024-13373-2. View Publication

Low dose methotrexate (LD‐MTX) remains the gold standard in rheumatoid arthritis (RA) therapy. Multiple mechanisms on a variety of immune cells contribute to the anti‐inflammatory effects of LD‐MTX. Inflammatory signaling is deeply implicated in hematopoiesis by regulating hematopoietic stem and progenitor cell (HSPC) fate decisions; raising the question of whether HSPC are also modulated by LD‐MTX. This is the first study to characterize the effects of LD‐MTX on HSPC. CD34 + HSPC were isolated from healthy donors' non‐mobilized peripheral blood. Resting and/or cycling HSPCs were treated with LD‐MTX [dose equivalent to that used in RA patients]. Flow cytometry was performed to assess HSPC viability,cell cycle,surface abundance of reduced folate carrier 1 (RFC1),proliferation,reactive oxygen species (ROS) levels,DNA double‐strand breaks,p38 activation,and CD34 + subpopulations. HSPC clonogenicity was tested in colony‐forming cell assays. Our results indicate that in cycling HSPC,membrane RFC1 is upregulated and,following LD‐MTX treatment,they accumulate more intracellular MTX than resting HSPC. In cycling HSPC,LD‐MTX inhibits HSPC expansion by promoting S‐phase cell‐cycle arrest,increases intracellular HSPC ROS levels and DNA damage,and reduces HSPC viability. Those effects involve the activation of the p38 MAPK pathway and are rescued by folinic acid. The effects of LD‐MTX are more evident in CD34 + CD38High progenitors. In non‐cycling HSPC,LD‐MTX also reduces the proliferative response while preserving their clonogenicity. In summary,HSPC uptake LD‐MTX differentially according to their cycling state. In turn,LD‐MTX results in reduced proliferation and the preservation of HSPC clonogenicity. View Publication

Cancer stem cells (CSCs) play crucial roles in tumor metastasis,therapy resistance,and immune evasion. Identifying and understanding the factors that regulate the stemness of tumor cells presents promising opportunities for developing effective therapeutic strategies. In this study on oral squamous cell carcinoma (OSCC),we confirmed the key role of KLF7 in maintaining the stemness of OSCC. Using chromatin immunoprecipitation sequencing and dual-luciferase assays,we identified ITGA2,a membrane receptor,as a key downstream gene regulated by KLF7 in the maintenance of stemness. Tumor sphere formation assays,flow cytometry analyses,and in vivo limiting dilution tumorigenicity evaluations demonstrated that knocking down ITGA2 significantly impaired stemness. Upon binding to its extracellular matrix (ECM) ligand,type I collagen,ITGA2 activates stemness-associated signaling pathways,including PI3K-AKT,MAPK,and Hippo. TC-I 15,a small-molecule inhibitor of the ITGA2-collagen interaction,significantly sensitizes oral squamous cell carcinoma (OSCC) to cisplatin in xenograft models. In summary,we reveal that the KLF7/ITGA2 axis is a crucial modulator of stemness in OSCC. Our findings suggest that ITGA2 is a promising therapeutic target,offering a novel anti-CSC strategy. Subject terms: Cancer stem cells,Cancer therapeutic resistance View Publication