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Induced pluripotent stem cells (IPS) are an artificially derived type of pluripotent stem cell,showing many of the same characteristics as natural pluripotent stem cells. IPS are a hopeful therapeutic model; however there is a critical need to determine their response to environmental toxins. Effects of arsenic on cells have been studied extensively; however,its effect on IPS is yet to be elucidated. Arsenic trioxide (ATO) has been shown to inhibit cell proliferation,induce apoptosis and genotoxicity in many cells. Based on ATOs action in other cells,we hypothesize that it will induce alterations in morphology,inhibit cell viability and induce a genotoxic effect on IPS. Cells were treated for 24 hours with ATO (0-9 µg/mL). Cell morphology,viability and DNA damage were documented. Results indicated sufficient changes in morphology of cell colonies mainly in cell ability to maintain grouping and ability to remain adherent. Cell viability decreased in a dose dependent manner. There were significant increases in tail length and moment as well as destruction of intact DNA as concentration increased. Exposure to ATO resulted in a reproducible dose dependent sequence of events marked by changes in morphology,decrease of cell viability,and induction of genotoxicity in IPS. View Publication

Fanconi anemia (FA) is an autosomal recessive disorder characterized by progressive bone marrow failure (BMF) during childhood,aside from numerous congenital abnormalities. FA mouse models have been generated; however,they do not fully mimic the hematopoietic phenotype. As there is mounting evidence that the hematopoietic impairment starts already in utero,a human pluripotent stem cell model would constitute a more appropriate system to investigate the mechanisms underlying BMF in FA and its developmental basis. Using zinc finger nuclease (ZFN) technology,we have created a knockout of FANCA in human embryonic stem cells (hESC). We introduced a selection cassette into exon 2 thereby disrupting the FANCA coding sequence and found that whereas mono-allelically targeted cells retain an unaltered proliferation potential,disruption of the second allele causes a severe growth disadvantage. As a result,heterogeneous cultures arise due to the presence of cells still carrying an unaffected FANCA allele,quickly outgrowing the knockout cells. When pure cultures of FANCA knockout hESC are pursued either through selection or single cell cloning,this rapidly results in growth arrest and such cultures cannot be maintained. These data highlight the importance of a functional FA pathway at the pluripotent stem cell stage. ?? 2014. View Publication

Nature Genetics 47,469 (2015). doi:10.1038/ng.3258 View Publication

Although studies have identified the presence of gut-associated cells in the enthesis of joints affected by spondylarthritis (SpA),a direct link through cellular transit between the gut and joint has yet to be formally demonstrated. Using KikGR transgenic mice to label in situ and track cellular trafficking from the distal colon to the joint under inflammatory conditions of both the gut and joint,we demonstrate bona-fide gut-joint trafficking of T cells from the colon epithelium,also called intraepithelial lymphocytes (IELs),to distal sites including joint enthesis,the pathogenic site of SpA. Similar to patients with SpA,colon IELs from the TNF$\Delta$ARE/+ mouse model of inflammatory bowel disease and SpA display heightened TNF production upon stimulation. Using ex vivo stimulation of photo-labeled gut-joint trafficked T cells from the popliteal lymph nodes of KikGR and KikGR TNF$\Delta$ARE/+ we saw that the CD4+ photo-labeled population was highly enriched for IL-17 competence in healthy as well as arthritic mice,however in the TNF$\Delta$ARE/+ mice these cells were additionally enriched for TNF. Using transfer of magnetically isolated IELs from TNF+/+ and TNF$\Delta$ARE/+ donors into Rag1 -/- hosts,we confirmed that IELs can exacerbate inflammatory processes in the joint. Finally,we blocked IEL recruitment to the colon epithelium using broad spectrum antibiotics in TNF$\Delta$ARE/+ mice. Antibiotic-treated mice had reduced gut-joint IEL migration,contained fewer Il-17A and TNF competent CD4+ T cells,and lessened joint pathology compared to untreated littermate controls. Together these results demonstrate that pro-inflammatory colon-derived IELs can exacerbate inflammatory responses in the joint through systemic trafficking,and that interference with this process through gut-targeted approaches has therapeutic potential in SpA. View Publication

In addition to antigen-driven signals,T cells need co-stimulatory signals for robust activation. Several receptors,including members of the tumor necrosis factor receptor superfamily (TNFRSF),can deliver co-stimulatory signals to T cells. Thioredoxin interacting protein (TXNIP) is an important inhibitor of glucose uptake and cell proliferation,but it is unknown how TXNIP is regulated in T cells. The aim of this study was to determine expression levels and regulation of TXNIP in human T cells. We found that na{\{i}}ve T cells express high levels of TXNIP and that treatment of blood samples with TNF results in rapid down-regulation of TXNIP in the T cells. TNF-induced TXNIP down-regulation correlated with increased glucose uptake. Furthermore we found that density gradient centrifugation (DGC) induced down-regulation of TXNIP. We demonstrate that DGC induced TNF production that paralleled the TXNIP down-regulation. Treatment of blood with toll-like receptor (TLR) ligands induced TNF production and TXNIP down-regulation suggesting that damage-associated molecular patterns (DAMPs) such as endogenous TLR ligands released during DGC play a role in DGC-induced TXNIP down-regulation. Finally we demonstrate that TNF-induced TXNIP down-regulation is dependent on caspase activity and is caused by caspase-mediated cleavage of TXNIP." View Publication

Tribbles pseudokinase 3 (TRIB3) expression significantly increases during terminal erythropoiesis in vivo. However,we found that TRIB3 expression remained relatively low during human embryonic stem cell (hESC) erythropoiesis,particularly in the late stage,where it is typically active. TRIB3 was expressed in megakaryocyte-erythrocyte progenitor cells and its low expression was necessary for megakaryocyte differentiation. Thus,we proposed that the high expression during late stage of erythropoiesis could be the clue for promotion of maturation of hESC-derived erythroid cells. To our knowledge,the role of TRIB3 in the late stage of erythropoiesis remains ambiguous. To address this,we generated inducible TRIB3 overexpression hESCs,named TRIB3tet-on OE H9,based on a Tet-On system. Then,we analyzed hemoglobin expression,condensed chromosomes,organelle clearance,and enucleation with or without doxycycline treatment. TRIB3tet-on OE H9 cells generated erythrocytes with a high proportion of orthochromatic erythroblast in flow cytometry,enhanced hemoglobin and related protein expression in Western blot,decreased nuclear area size,promoted enucleation rate,decreased lysosome and mitochondria number,more colocalization of LC3 with LAMP1 (lysosome marker) and TOM20 (mitochondria marker) and up-regulated mitophagy-related protein expression after treatment with 2 ?g/mL doxycycline. Our results showed that TRIB3 overexpression during terminal erythropoiesis may promote the maturation of erythroid cells. Therefore,our study delineates the role of TRIB3 in terminal erythropoiesis,and reveals TRIB3 as a key regulator of UPS and downstream mitophagy by ensuring appropriate mitochondrial clearance during the compaction of chromatin. Highlights•TRIB3 boosts erythroid cell maturation.•Key insights into erythropoiesis from hESCs.•Enhanced ubiquitin-proteasome system and downstream mitophagy in erythroid differentiation. View Publication

Introduction: The lack of functional hepatocytes poses a significant challenge for drug safety testing and therapeutic applications due to the inability of mature hepatocytes to expand and their tendency to lose functionality in vitro. Previous studies have demonstrated the potential of Human Liver Stem Cells (HLSCs) to differentiate into hepatocyte-like cells within an in vitro rotary cell culture system,guided by a combination of growth factors and molecules known to regulate hepatocyte maturation. In this study,we employed a matrix multi-assay approach to comprehensively characterize HLSC differentiation. Methods: We evaluated the expression of hepatic markers using qRT-PCR,immunofluorescence,and Western blot analysis. Additionally,we measured urea and FVIII secretion into the supernatant and developed an updated indocyanine green in vitro assay to assess hepatocyte functionality. Results: Molecular analyses of differentiated HLSC aggregates revealed significant upregulation of hepatic genes,including CYP450,urea cycle enzymes,and uptake transporters exclusively expressed on the sinusoidal side of mature hepatocytes,evident as early as 1 day post-differentiation. Interestingly,HLSCs transiently upregulated stem cell markers during differentiation,followed by downregulation after 7 days. Furthermore,differentiated aggregates demonstrated the ability to release urea and FVIII into the supernatant as early as the first 24 h,with accumulation over time. Discussion: These findings suggest that a 3D rotation culture system may facilitate rapid hepatic differentiation of HLSCs. Despite the limitations of this rotary culture system,its unique advantages hold promise for characterizing HLSC GMP batches for clinical applications. View Publication

BackgroundStem cell-derived secreted factors could protect neurons in neurodegenerative disease or after injury. The exact neuroprotective components in the secretome remain challenging to discover. Here we developed a cell-to-cell interaction model to identify a retinal ganglion cell (RGC)-protective factor derived from induced pluripotent stem cells (iPSCs).MethodsPrimary RGCs were co-cultured with iPSCs or treated with iPSC-conditioned media in vitro. Cell viability were assayed using live-cell staining,and culture supernatant were analyzed via multiplexed antibody-based assays and ELISA. In vivo tests were carried out under mouse optic nerve crush model and RGC transplantation study in rats. Paired t-tests were used for data analysis between two groups.ResultsRGC viability was significantly enhanced when iPSCs were first stimulated with RGC-derived supernatant before iPSC-conditioned medium was collected and added into RGC culture. A significant increase of stem cell growth factor-beta (SCGF-?) concentration was detected in the latter conditioned medium. SCGF-? enhanced RGC survival in vitro and in vivo,and RGC-derived interleukin-12(p70) (IL-12[p70]) promotes secretion of iPSC-derived SCGF-?. Downstream of this IL-12(p70)-to-SCGF-? axis,ngn2 was significantly upregulated,and was found both necessary and sufficient for RGC survival.ConclusionThis study addresses a longstanding question of how neurons and stem cells interact to promote neuroprotection,and define a novel molecular interaction pathway whereby RGC’s secretion of IL-12(p70) enhances iPSCs’ secretion of SCGF-?,and SCGF-? protects RGCs via upregulating ngn2,suggesting that neurons may call on stem cells for their own protection.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13287-025-04198-5. View Publication

A major limitation of chimeric antigen receptor (CAR) T cell therapies is the poor persistence of these cells in vivo1. The expression of memory-associated genes in CAR T cells is linked to their long-term persistence in patients and clinical efficacy2–6,suggesting that memory programs may underpin durable CAR T cell function. Here we show that the transcription factor FOXO1 is responsible for promoting memory and restraining exhaustion in human CAR T cells. Pharmacological inhibition or gene editing of endogenous FOXO1 diminished the expression of memory-associated genes,promoted an exhaustion-like phenotype and impaired the antitumour activity of CAR T cells. Overexpression of FOXO1 induced a gene-expression program consistent with T cell memory and increased chromatin accessibility at FOXO1-binding motifs. CAR T cells that overexpressed FOXO1 retained their function,memory potential and metabolic fitness in settings of chronic stimulation,and exhibited enhanced persistence and tumour control in vivo. By contrast,overexpression of TCF1 (encoded by TCF7) did not enforce canonical memory programs or enhance the potency of CAR T cells. Notably,FOXO1 activity correlated with positive clinical outcomes of patients treated with CAR T cells or tumour-infiltrating lymphocytes,underscoring the clinical relevance of FOXO1 in cancer immunotherapy. Our results show that overexpressing FOXO1 can increase the antitumour activity of human CAR T cells,and highlight memory reprogramming as a broadly applicable approach for optimizing therapeutic T cell states. The transcription factor FOXO1 has a key role in human T cell memory,and manipulating FOXO1 expression could provide a way to enhance CAR T cell therapies by increasing CAR T cell persistence and antitumour activity. View Publication

IntroductionSepsis engenders distinct host immunologic changes that include the expansion of myeloid-derived suppressor cells (MDSCs). These cells play a physiologic role in tempering acute inflammatory responses but can persist in patients who develop chronic critical illness.MethodsCellular Indexing of Transcriptomes and Epitopes by Sequencing and transcriptomic analysis are used to describe MDSC subpopulations based on differential gene expression,RNA velocities,and biologic process clustering.ResultsWe identify a unique lineage and differentiation pathway for MDSCs after sepsis and describe a novel MDSC subpopulation. Additionally,we report that the heterogeneous response of the myeloid compartment of blood to sepsis is dependent on clinical outcome.DiscussionThe origins and lineage of these MDSC subpopulations were previously assumed to be discrete and unidirectional; however,these cells exhibit a dynamic phenotype with considerable plasticity. View Publication

Acute Myeloid Leukemia (AML) is caused by multiple mutations which dysregulate growth and differentiation of myeloid cells. Cells adopt different gene regulatory networks specific to individual mutations,maintaining a rapidly proliferating blast cell population with fatal consequences for the patient if not treated. The most common treatment option is still chemotherapy which targets such cells. However,patients harbour a population of quiescent leukemic stem cells (LSCs) which can emerge from quiescence to trigger relapse after therapy. The processes that allow such cells to re-grow remain unknown. Here,we examine the well characterised t(8;21) AML sub-type as a model to address this question. Using four primary AML samples and a novel t(8;21) patient-derived xenograft model,we show that t(8;21) LSCs aberrantly activate the VEGF and IL-5 signalling pathways. Both pathways operate within a regulatory circuit consisting of the driver oncoprotein RUNX1::ETO and an AP-1/GATA2 axis allowing LSCs to re-enter the cell cycle while preserving self-renewal capacity. Subject terms: Cancer stem cells,Acute myeloid leukaemia,Target validation 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