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Pancreatic β cells derived from human induced pluripotent stem cells (hiPSCs) represent a promising therapeutic avenue in regenerative medicine for diabetes treatment. However,current differentiation protocols lack the specificity and efficiency required to reliably produce fully functional β cells,limiting their clinical applicability. Epigenetic barriers,such as histone modifications,may hinder proper differentiation and the acquisition of essential maturation markers in these cells. Methods: hiPSCs were cultured under feeder-free conditions and subjected to lentiviral transduction with shRNA constructs to silence KDM4A. Differentiation into pancreatic β-like cells was performed using stepwise protocols,with or without doxycycline supplementation,to evaluate the effect of KDM4A suppression. Gene expression was quantified by RT-qPCR,protein expression was assessed by western blotting and immunofluorescence,and functional insulin release was determined by glucose-stimulated insulin secretion (GSIS) assays. Statistical analysis was conducted using unpaired two-tailed Student’s t-tests,with significance set at p < 0.05. Results: A reduction in pancreatic development proteins was observed in the different differentiation states evaluated,after blocking KDM4A expression. Knockdown of KDM4A significantly reduced the expression of pancreatic β-cell genes,such as PDX1,Nkx6.1,and Ins,by 50% compared to WT iPSCs differentiated under the same conditions. Similarly,glucose-stimulated insulin secretion was reduced by approximately 80% in KDM4A-deficient β-like cells. Conclusions: These results emphasize the critical role of histone demethylation in hiPSC differentiation toward β cells. Our findings identify KDM4A as a key epigenetic regulator,suggesting that its modulation could enhance the generation of functional β cells for regenerative medicine in diabetes. View Publication

Gastrointestinal (GI) dysfunction,characterized by severe diarrhea and dehydration,is a central contributor to morbidity and mortality in filovirus disease in patients,yet the role of the epithelium in this clinical outcome remains poorly defined. Here,we employ induced pluripotent stem cell (iPSC)-derived human intestinal (HIOs) and colonic organoids (HCOs) to model Ebola virus (EBOV) and Marburg virus (MARV) infection. These organoids are permissive to filovirus infection and support viral replication. Bulk RNA sequencing revealed distinct intestinal and colonic epithelial responses,including apical and junctional disruption and a delayed virus-specific induction of interferon-stimulated genes. Moreover,infection impaired adenylate cyclase signaling and CFTR-mediated ion transport,providing mechanistic insight into virus-induced secretory diarrhea. This platform recapitulates key features of human GI pathology in filoviral disease and serves as a powerful system to dissect host-pathogen interactions and identify therapeutic targets. Author summaryEbola virus (EBOV) and Marburg virus (MARV) are among the most lethal viruses known. Infection with these viruses leads to severe disease and death. One of their most harmful effects is damage to the gastrointestinal tract,causing intense diarrhea and life-threatening dehydration. Yet,how these viruses affect the gut remains poorly understood. In this study,we used human mini-guts—small,three-dimensional tissues grown from stem cells that mimic the human intestinal and colonic epithelium—to investigate how these viruses interact with gut epithelial cells. We found that both EBOV and MARV infect and replicate in these tissues,disrupt key barrier structures,and interfere with the cells’ ability to regulate fluid secretion. These effects mirror the severe symptoms seen in patients. Our study provides new insight into how EBOV and MARV damage the gut and identifies specific cellular pathways that may be targeted for treatment. This research not only improves our understanding of EBOV and MARV infections but also offers new infection platforms for testing therapies aimed at protecting the gastrointestinal system during filovirus outbreaks. View Publication

Background: Biliary atresia (BA) is the most prevalent serious neonatal biliary obstructive disorder and is a complex multifactorial liver disorder. Genome-wide association studies have identified Adducin 3 (ADD3) as a BA susceptibility gene but the mechanisms involved in disease causation and progression remain unclear. Methods: ADD3 knockout human pluripotent stem cells were differentiated into cholangiocyte organoids to assess the effect of ADD3 deletion on biliary development in vitro. Add3 deletion in rhesus rotavirus (RRV)-induced experimental BA mice were employed as the in vivo model to address the impact of reduced Add3 expression on BA pathogenesis. Findings: ADD3 knockout organoids displayed defective cholangiocyte differentiation,failure in the recruitment of βII-spectrin to the cell membrane,abnormal primary cilia development,reduced expression of tight junction proteins,lower transepithelial electrical resistance (TEER) and increased paracellular permeability. Statistical significantly reduced tight junction (TJ) proteins expression and lower TEER in Add3+/− and Add3−/− liver tissue-derived cholangiocytes were observed. Reduced number of TJs and enlarged paracellular spaces without any detectable TJ were detected in the intra-hepatic bile ducts of Add3+/− and Add3−/− livers. A statistical significantly higher incidence and a more advanced form of BA with statistical significantly higher serum bilirubin,liver necrosis and fibrosis,and accumulation of macrophages and activated hepatic stellate cells were observed in Add3 knockout BA mice as compared to wild-type BA mice. Interpretation: Dysregulated ADD3 expression caused an abnormal development and impaired barrier function of cholangiocytes,and the resultant increase in bile duct permeability rendered the foetus/neonate susceptible to a more severe injury response to an external insult. The findings support the hypothetical pathogenic model of genetic susceptibility genes being involved in hepatobiliary development/structure,and the perturbed embryogenesis of the biliary tree and its disrupt integrity increase the host susceptibility to biliary injury and BA. View Publication

USP30,a ubiquitin‐specific protease,primarily characterized as a mitochondrial deubiquitinase regulating mitophagy,has not been previously reported to have nuclear functions. In this study,we demonstrate that USP30 is present in both mitochondrial and nuclear compartments. Nutrient deprivation triggers USP30 nuclear translocation via an N‐terminal nuclear localization signal (NLS),mediated through suppression of mTORC1‐dependent phosphorylation at serine 104,a modification constraining nuclear entry. Nuclear USP30 acts as a tumor suppressor by inhibiting cancer stemness and chemoresistance in triple‐negative breast cancer (TNBC) cells. Mechanistically,USP30 directly interacts with and deubiquitinates the transcription factor TCF/LEF1 at K379 and K382 residues,disrupting recruitment of CBP/P300 co‐activators to the β‐catenin/LEF1 complex. This abolishes β‐catenin/LEF1 transactivation and suppresses WNT signaling. Clinically,USP30 is downregulated in TNBC and cancer stem cells (CSCs),with notably reduced nuclear levels in cancer tissues. Overexpression of nuclear USP30 markedly reduces lung metastatic burden in TNBC mouse models. These findings uncover a novel role for nuclear USP30 in regulating cancer stemness and suggest that targeting the dynamic relocalization of USP30 from mitochondria to the nucleus could offer new therapeutic strategies for breast cancer metastasis. View Publication

Acute myeloid leukemia (AML) is primarily driven by leukemic stem cells (LSCs),the main cause of relapse and therapy resistance. Here,we discover that LSCs are predominantly small and mechanically soft. These mechanical properties enable their selective isolation using microfluidic chips. Single-cell RNA-sequencing of primary human AML bone marrow identifies enrichment of LSCs within the FSClow ALDH1A1+ subpopulation,which exhibits long-term stemness in functional assays. Notably,inhibiting ALDH1A1 in these cells promotes F-actin polymerization and increases cellular stiffness,reducing their stemness while enhancing their susceptibility to natural killer (NK) cell-mediated cytotoxicity. In AML patient-derived xenograft models,the combination of ALDH1A1 inhibition with NK cell therapy markedly suppresses leukemia progression. These findings suggest that targeting the mechanical properties of LSC offers a promising strategy to overcome AML treatment resistance,providing insights into stem cell mechanobiology and paving the way for combining targeted therapies with immunotherapy to improve clinical outcomes. Leukemic stem cells (LSCs) drive relapse and therapy resistance in acute myeloid leukemia (AML). Here,the authors show that increasing the stiffness of LSCs reduces their stemness and enhances their susceptibility to natural killer cell-mediated immunotherapy in AML. View Publication

Systemic sclerosis (SSc) is an autoimmune disease marked by fibrosis and extensive autoantibody production. Although B-cell depletion with rituximab (RTX) has shown clinical benefit,predictive biomarkers of response remain elusive. Here,we apply proteome-wide autoantibody screening using wet protein arrays covering 13,455 human antigens in serum samples from participants of the randomized trial of RTX. We identify a significant elevation in the total autoantibody levels in SSc compared to healthy controls,with greater reductions post-treatment observed in RTX high responders than in low responders. A stepwise selection highlights 88 clinically relevant autoantibodies,including those targeting G protein-coupled receptors. Among them,anti-C-C motif chemokine receptor 8 (CCR8) autoantibodies are functionally validated by cell-based assays using CCR8-overexpressing HEK293 cells. Furthermore,in a bleomycin-induced mouse model,anti-CCR8 antibody administration exacerbates dermal fibrosis and modifies immune cell infiltration. Although external validation with multiple comparison adjustment is further required,these findings reveal an autoantibody signature associated with therapeutic response and pathogenic potential in SSc,providing a foundation for precision immunotherapy and mechanistic insights into disease progression. B-cell depletion benefits systemic sclerosis,but predictive biomarkers remain limited. The authors here map autoantibody profiles using proteome-wide screening,identify C-C motif chemokine receptor 8-targeting autoantibodies with functional impact,suggesting novel pathophysiology and precision therapy targets. View Publication

Older adults have decreased vaccine efficacy,but the adjuvanted recombinant VZV-gE zoster vaccine (RZV) is highly efficacious. We investigated memory-like innate immune responses after RZV and after the zoster vaccine live (ZVL),which is much less efficacious. RZV increased NK,monocyte,and DC activation in response to in vitro VZV-gE stimulation for up to 5 years post-vaccination,while ZVL increased only DC responses to VZV for up to 90 days. In purified monocyte and NK cell cocultures,RZV recipients showed increased responses to VZV-gE,HCMV and HSV antigenic stimulation post-vaccination. ATAC-seq analysis of purified monocytes revealed decreased accessibility in areas of the TGFβ1 gene. scRNA-seq and immunoproteomics confirmed decreased TGFβ1 transcription and translation,respectively. Exogenous supplementation and inhibition of TGFβ1 modulated in vitro monocyte responses to VZV-gE. In conclusion,RZV generated homologous (VZV-gE) and heterologous (HCMV,HSV) trained immunity in monocytes through genomic repression of the regulatory cytokine TGFβ-1. Cytokine modulation may represent a novel mechanism of generating trained immunity in myeloid cells. Author summaryOlder adults have decreased vaccine efficacy,but the adjuvanted recombinant varicella zoster virus (VZV)-gE zoster vaccine (RZV; Shingrix™) is highly efficacious. We investigated memory-like innate immune responses after RZV and after the zoster vaccine live (ZVL; Zostavax™),which is much less efficacious than RZV. We found that RZV increased the functionality of several innate immune cell subsets against VZV-gE other herpesviruses. The increase in functionality was associated with decreased production of the inhibitory cytokine TGFβ1,which may have resulted from decreased ability to use the TGFβ1 gene as a template for the synthesis of its product. We concluded that RZV generated homologous (VZV-gE) and heterologous (other herpesviruses) memory-like responses in innate immune cell subsets through genomic repression of the regulatory cytokine TGFβ-1. View Publication

Osteosarcoma (OSA) is the most common primary bone tumor in children and adolescents,yet outcomes have remained largely unchanged for over 40 years. While chimeric antigen receptor (CAR) T cell therapy has shown success in blood cancers,it faces major limitations in solid tumors due to immune evasion,antigen loss,and immunosuppressive tumor microenvironments. Natural killer (NK) cells offer several advantages over T cells,including multiple killing mechanisms and lower risks of graft-versus-host disease,neurotoxicity,and cytokine release syndrome,making them promising candidates for off-the-shelf cell therapies. However,unmodified NK cells have shown limited efficacy in clinical settings due to poor engraftment,persistence,and tumor-mediated suppression. To overcome these barriers,we developed a cost-effective method to engineer CAR NK cells targeting CD70,a tumor antigen overexpressed in relapsed and metastatic OSA. We further enhanced these cells by incorporating soluble interleukin-15 (IL-15) and a dominant-negative TGF-β receptor,creating “armored” CAR NK cells. These engineered cells resist transforming growth factor β (TGF-β) suppression,secrete IL-15,and demonstrate improved cytotoxicity,persistence,and tumor homing in both in vitro and in vivo models. Our findings support CD70 CAR NK cells as a promising immunotherapeutic strategy for relapsed and metastatic OSA. Graphical abstract Engineered “armored” CAR NK cells targeting CD70 overcome immune suppression in osteosarcoma,enhancing persistence,tumor homing,and cytotoxicity. This study presents a promising off-the-shelf immunotherapy approach for relapsed and metastatic OSA,offering a potential advance where current treatments have stagnated for decades. View Publication

INTRODUCTION: Alzheimer's disease (AD) pathology is complex and involves mitochondrial dysfunction. There are emerging therapies targeting mitochondrial function in clinical trials for AD. This highlights the need for biomarkers that measure mitochondrial function. METHODS: We determined the utility of a novel blood‐based mitochondrial biomarker,the mitochondrial functional index (MFI),in the context of AD in a pilot study.RESULTS: In vitro and in vivo models of AD had a reduced MFI. MFI was lower in human AD subjects and APOE ????4 carriers. Receiver operating characteristic analysis showed MFI had a higher area under the curve than other plasma biomarkers. The MFI biomarker correlated with the Mini‐Mental State Examination (MMSE) and the Clinical Dementia Rating (CDR) scale. DISCUSSION: This study highlights the potential utility of MFI as a functional blood‐based mitochondrial biomarker to interrogate energy metabolism. Ongoing studies are examining the relationship of MFI with brain energy metabolism outcomes. Highlights: The MFI biomarker is reduced in cell and animal models of AD. The MFI biomarker is reduced in human AD subjects and APOE ε4 carriers. The MFI biomarker can discriminate between subjects with normal cognition and AD with better performance than other plasma biomarkers. The MFI biomarker correlates with cognitive scores. View Publication

BACKGROUND: The discovery of induced pluripotent stem cells revolutionized regenerative medicine,providing a source for generating induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs). AIM: To evaluate and compare five iMSC differentiation protocols,assessing their efficiency,phenotypic characteristics,and functional properties relative to primary mesenchymal stem cells (MSCs). METHODS: Five iMSC differentiation protocols were assessed: SB431542-based differentiation (iMSC1,iMSC3),an iMatrix-free method (iMSC2),growth factor supplementation (iMSC4),and embryoid body formation with retinoic acid (EB-iMSC). iMSC identity was confirmed according to the International Society for Cell & Gene Therapy 2006 criteria,requiring expression of surface markers (CD105,CD73,CD90) and absence of pluripotency markers. Functional assays were conducted to evaluate differentiation potential (osteogenic and adipogenic),proliferation,mitochondrial function,reactive oxygen species,senescence,and migration. RESULTS: All iMSC types expressed MSC markers and lacked pluripotency markers. EB-iMSC and iMSC2 showed enhanced osteogenesis (runt-related transcription factor 2; P ≤ 0.01 and P ≤ 0.0001,respectively),while adipogenic potential was reduced in iMSC2 (Adipsin; P ≤ 0.01) and EB-iMSC (Adipsin and peroxisome proliferator-activated receptor gamma; P ≤ 0.0001 and P ≤ 0.01,respectively). Proliferation was comparable or superior to bone marrow MSCs,except in iMSC1,with iMSC4 showing the highest rate (MTT assay; P values ranged from 0.01 to 0.001). Despite reduced mitochondrial health in iMSC3 and iMSC4 (P ≤ 0.001),reactive oxygen species levels were lower in all iMSCs (P values ranged from 0.001 to 0.0001),and senescence was significantly reduced in all iMSCs with the exception of iMSC1 (P values ranged from 0.01 to 0.0001). Migration was most reduced in iMSC4 (P ≤ 0.001 at 24 hours and P ≤ 0.0001 at 48 hours). CONCLUSION: While all protocols generated functional iMSCs,variations in differentiation,proliferation,and function emphasize the impact of protocol selection. These findings contribute to optimizing iMSC generation for research and clinical applications. View Publication

Multiple myeloma (MM) is the second most common hematological malignancy,characterized by a clonal expansion of malignant plasma cells in bone marrow. Monoclonal gammopathy of undetermined significance (MGUS) is the premalignant condition of MM. The tumor microenvironment is thought to influence the progression from premalignant conditions. Myeloid‐derived suppressor cells (MDSCs) are a heterogenous group of different cellular subsets with myeloid origin,characterized by their ability to inhibit T‐cell responses. MDSC are thought to play an important immunoregulatory role in different diseases,and in many cancers their levels seem to correlate with a poor prognosis. There are three different subsets,the neutrophil‐like polymorphonuclear (PMN)‐MDSC,the monocyte‐like (M)‐MDSC,and the immature early (e)MDSC. In this study,we investigate the levels and functions of all MDSC subsets in the bone marrow of both MGUS and MM patients and compare it to blood MDSC. We found that MDSC levels are not increased in neither the blood nor bone marrow of MGUS or MM patients,and they lack strong T‐cell suppressive abilities. Blood PMN‐MDSC seems to have a small inhibitory effect,but mature neutrophils were more suppressive. Interestingly,eMDSC levels were decreased in the blood of MM patients. Our data indicate that MDSC are not key players in the pathogenesis of MM,but that mature neutrophils may be more important as they have a stronger immunoregulatory effect. View Publication

Cis-regulatory elements (CREs) are noncoding DNA regions regulating cell-type-specific gene expression programs by interacting with distal gene promoters. Here,we aim to decode the function and spatial organization of CRE-promoter interactions in human cardiomyocytes. We analyzed the epigenome and chromatin interactions of human male atrial,ventricular,and failing cardiomyocytes. Atrial and ventricular cardiomyocytes harbored chamber-specific CRE-promoter interactions modulating gene expression as confirmed by functional epigenetic silencing. These CRE-promoter interactions explain the distinct contribution of non-coding genetic variants to atrial and ventricular diseases,such as dilated cardiomyopathy and arrhythmias. We dissected the prototypic KCNJ2 locus,encoding a potassium channel associated with ventricular arrhythmia susceptibility. Functional epigenetic silencing confirmed that CREs,harboring QT-duration-associated genetic risk factors,modulate KCNJ2 gene expression levels,alter KCNJ2-dependent channel currents,and affect cardiomyocyte repolarization. The presented human CM-specific chromatin interaction analysis provides key insights into regulatory mechanisms and aids in interpreting genetic risk factors. Here the authors functionally test and resolve the spatial genome organization of cis-regulatory elements and genetic variants in atrial,ventricular,and failing human cardiomyocytes and linked them to heart disease traits,including QT syndrome. View Publication