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To better understand endogenous parameters that influence pluripotent cell differentiation we used human embryonic stem cells (hESCs) as a model system. We demonstrate that differentiation trajectories in aggregate (embryoid body [EB])-induced differentiation,a common approach to mimic some of the spatial and temporal aspects of in vivo development,are affected by three factors: input hESC composition,input hESC colony size,and EB size. Using a microcontact printing approach,size-specified hESC colonies were formed by plating single-cell suspensions onto micropatterned (MP) extracellular matrix islands. Subsequently,size-controlled EBs were formed by transferring entire colonies into suspension culture enabling the independent investigation of colony and aggregate size effects on differentiation induction. Gene and protein expression analysis of MP-hESC populations revealed that the ratio of Gata6 (endoderm-associated marker) to Pax6 (neural-associated marker) expression increased with decreasing colony size. Moreover,upon forming EBs from these MP-hESCs,we observed that differentiation trajectories were affected by both colony and EB size-influenced parameters. In MP-EBs generated from endoderm-biased (high Gata6/Pax6) input hESCs,higher mesoderm and cardiac induction was observed at larger EB sizes. Conversely,neural-biased (low Gata6/Pax6) input hESCs generated MP-EBs that exhibited higher cardiac induction in smaller EBs. Our analysis demonstrates that heterogeneity in hESC colony and aggregate size,typical in most differentiation strategies,produces subsets of appropriate conditions for differentiation into specific cell types. Moreover,our findings suggest that the local microenvironment modulates endogenous parameters that can be used to influence pluripotent cell differentiation trajectories. View Publication

Alcohol abuse predisposes the host to bacterial infections. In response to bacterial infection,the bone marrow hematopoietic activity shifts toward granulocyte production,which is critical for enhancing host defense. This study investigated the hematopoietic precursor cell response to bacteremia and how alcohol affects this response. Acute alcohol intoxication was induced in BALB/c mice 30 min before initiation of Escherichia coli bacteremia. Bacteremia caused a significant increase in the number of bone marrow lineage (lin(-))-c-kit(+)Sca-1(+) cells. Marrow lin(-)c-kit(+)Sca-1(+) cells isolated from bacteremic mice showed an increase in CFU-granulocyte/macrophage activity compared with controls. In addition to enhanced proliferation of lin(-)c-kit(+)Sca-1(+) cells as reflected by BrdU incorporation,phenotypic inversion of lin(-)c-kit(+)Sca-1(+)Sca-1(-) cells primarily accounted for the rapid increase in marrow lin(-)c-kit(+)Sca-1(+) cells following bacteremia. Bacteremia increased plasma concentration of TNF-alpha. Culture of marrow lin(-)c-kit(+)Sca-1(+)Sca-1(-) cells with murine rTNF-alpha for 24 h caused a dose-dependent increase in conversion of these cells to lin(-)c-kit(+)Sca-1(+) cells. Sca-1 mRNA expression by the cultured cells was also up-regulated following TNF-alpha stimulation. Acute alcohol intoxication inhibited the increase in the number of lin(-)c-kit(+)Sca-1(+) cells in the bone marrow after E. coli infection. Alcohol impeded the increase in BrdU incorporation into marrow lin(-)c-kit(+)Sca-1(+) cells in response to bacteremia. Alcohol also suppressed the plasma TNF-alpha response to bacteremia and inhibited TNF-alpha-induced phenotypic inversion of lin(-)c-kit(+)Sca-1(+)Sca-1(-) cells in vitro. These data show that alcohol inhibits the hematopoietic precursor cell response to bacteremia,which may serve as one mechanism underlying the impaired host defense in alcohol abusers with severe bacterial infections. View Publication

Recent studies involving bone marrow mesenchymal stromal cells (MSCs) demonstrated that interferon (IFN)-gamma stimulation induces major histocompatibility complex (MHC) class II-mediated antigen presentation in MSCs both in vitro and in vivo. Concordantly,we investigated the ability of MSCs to present extracellular antigen through their MHC class I molecules,a process known as cross-presentation. Using an in vitro antigen presentation assay,we demonstrated that murine MSCs can cross-present soluble ovalbumin (OVA) to naive CD8(+) T cells from OT-I mice. Cross-presentation by MSC was proteasome dependent and partly dependent on transporter associated with antigen-processing molecules. Pretreatment of MSC with IFN-gamma increased cross-presentation by up-regulating antigen processing and presentation. However,although the transcription of the transporter associated with antigen processing-1 molecules and the immunoproteasome subunit LMP2 induced by IFN-gamma was inhibited by transforming growth factor-beta,the overall cross-presentation capacity of MSCs remained unchanged after transforming growth factor-beta treatment. These observations were validated in vivo by performing an immune reconstitution assay in beta(2)-microglobulin(-/-) mice and show that OVA cross-presentation by MSCs induces the proliferation of naive OVA-specific CD8(+) T cells. In conclusion,we demonstrate that MSCs can cross-present exogenous antigen and induce an effective CD8(+) T-cell immune response,a property that could be exploited as a therapeutic cell-based immune biopharmaceutic for the treatment of cancer or infectious diseases. View Publication

Hematopoietic stem cell (HSC) engraftment is a multistep process involving HSC homing to bone marrow,self-renewal,proliferation,and differentiation to mature blood cells. Here,we show that loss of p190-B RhoGTPase activating protein,a negative regulator of Rho GTPases,results in enhanced long-term engraftment during serial transplantation. This effect is associated with maintenance of functional HSC-enriched cells. Furthermore,loss of p190-B led to marked improvement of HSC in vivo repopulation capacity during ex vivo culture without altering proliferation and multilineage differentiation of HSC and progeny. Transcriptional analysis revealed that p190-B deficiency represses the up-regulation of p16(Ink4a) in HSCs in primary and secondary transplantation recipients,providing a possible mechanism of p190-B-mediated HSC functions. Our study defines p190-B as a critical transducer element of HSC self-renewal activity and long-term engraftment,thus suggesting that p190-B is a target for HSC-based therapies requiring maintenance of engraftment phenotype. View Publication

Protein kinase Ciota (PKCiota) is an oncogene required for maintenance of the transformed phenotype of non-small cell lung cancer cells. However,the role of PKCiota in lung tumor development has not been investigated. To address this question,we established a mouse model in which oncogenic Kras(G12D) is activated by Cre-mediated recombination in the lung with or without simultaneous genetic loss of the mouse PKCiota gene,Prkci. Genetic loss of Prkci dramatically inhibits Kras-initiated hyperplasia and subsequent lung tumor formation in vivo. This effect correlates with a defect in the ability of Prkci-deficient bronchioalveolar stem cells to undergo Kras-mediated expansion and morphologic transformation in vitro and in vivo. Furthermore,the small molecule PKCiota inhibitor aurothiomalate inhibits Kras-mediated bronchioalveolar stem cell expansion and lung tumor growth in vivo. Thus,Prkci is required for oncogene-induced expansion and transformation of tumor-initiating lung stem cells. Furthermore,aurothiomalate is an effective antitumor agent that targets the tumor-initiating stem cell niche in vivo. These data have important implications for PKCiota as a therapeutic target and for the clinical use of aurothiomalate for lung cancer treatment. View Publication

Human induced pluripotent stem cells (hiPSCs) provide new possibilities for regenerative therapies. In order for this potential to be achieved,it is critical to efficiently monitor the differentiation of these hiPSCs into specific lineages. Here,we describe a lentiviral reporter vector sensitive to specific microRNAs (miRNA) to show that a single vector bearing multiple miRNA target sequences conjugated to different reporters can be used to monitor hiPSC formation and subsequent differentiation from human fetal fibroblasts (HFFs). The reporter vector encodes EGFP conjugated to the targets of human embryonic stem cell (hESC) specific miRNAs (miR-302a and miR-302d) and mCherry conjugated to the targets of differentiated cells specific miRNAs (miR-142-3p,miR-155,and miR-223). The vector was used to track reprogramming of HFF to iPSC. HFFs co-transduced with this reporter vector and vectors encoding 4 reprogramming factors (OCT4,SOX2,KLF4 and cMYC) were mostly positive for EGFP (67%) at an early stage of hiPSC formation. EGFP expression gradually disappeared and mCherry expression increased indicating less miRNAs specific to differentiated cells and expression of miRNAs specific to hESCs. Upon differentiation of the hiPSC into embryoid bodies,a large fraction of these hiPSCs regained EGFP expression and some of those cells became single positive for EGFP. Further differentiation into neural lineages showed distinct structures demarcated by either EGFP or mCherry expression. These findings demonstrate that a miRNA dependent reporter vector can be a useful tool to monitor living cells during reprogramming of hiPSC and subsequent differentiation to lineage specific cells. View Publication

Characterization of tissue surrounding glioblastoma (GBM) is a focus for translational research because tumor recurrence invariably occurs in this area. We investigated the expression of the progenitor/stem cell markers GD3 ganglioside and NG2 proteoglycan in GBM,peritumor tissue (brain adjacent to tumor,BAT) and cancer stem-like cells (CSCs) isolated from GBM (GCSCs) and BAT (PCSCs). GD3 and NG2 immunohistochemistry was performed in paired GBM and BAT specimens from 40 patients. Double-immunofluorescence was carried out to characterize NG2-positive cells of vessel walls. GD3 and NG2 expression was investigated in GCSCs and PCSCs whose tumorigenicity was also evaluated in Scid/bg mice. GD3 and NG2 expression was higher in tumor tissue than in BAT. NG2 decreased as the distance from tumor margin increased,regardless of the tumor cell presence,whereas GD3 correlated with neoplastic infiltration. In BAT,NG2 was coexpressed with a-smooth muscle actin (a-SMA) in pericytes and with nestin in the endothelium. Higher levels of NG2 mRNA and protein were found in GCSCs while GD3 synthase was expressed at similar levels in the 2 CSC populations. PCSCs had lower tumorigenicity than GCSCs. These data suggest the possible involvement of GD3 and NG2 in pre/pro-tumorigenic events occurring in the complex microenvironment of the tissue surrounding GBM. View Publication

Human bocavirus 1 (HBoV1) is a human parvovirus that causes acute respiratory tract infections in young children. In this study,we confirmed that,when polarized/well-differentiated human airway epithelia are infected with HBoV1in vitro,they develop damage characterized by barrier function disruption and cell hypotrophy. Cell death mechanism analyses indicated that the infection induced pyroptotic cell death characterized by caspase-1 activation. Unlike infections with other parvoviruses,HBoV1 infection did not activate the apoptotic or necroptotic cell death pathway. When the NLRP3-ASC-caspase-1 inflammasome-induced pathway was inhibited by short hairpin RNA (shRNA),HBoV1-induced cell death dropped significantly; thus,NLRP3 mediated by ASC appears to be the pattern recognition receptor driving HBoV1 infection-induced pyroptosis. HBoV1 infection induced steady increases in the expression of interleukin 1α (IL-1α) and IL-18. HBoV1 infection was also associated with the marked expression of the antiapoptotic genesBIRC5andIFI6When the expression ofBIRC5and/orIFI6was inhibited by shRNA,the infected cells underwent apoptosis rather than pyroptosis,as indicated by increased cleaved caspase-3 levels and the absence of caspase-1.BIRC5and/orIFI6gene inhibition also significantly reduced HBoV1 replication. Thus,HBoV1 infection of human airway epithelial cells activates antiapoptotic proteins that suppress apoptosis and promote pyroptosis. This response may have evolved to confer a replicative advantage,thus allowing HBoV1 to establish a persistent airway epithelial infection. This is the first report of pyroptosis in airway epithelia infected by a respiratory virus.IMPORTANCEMicrobial infection of immune cells often induces pyroptosis,which is mediated by a cytosolic protein complex called the inflammasome that senses microbial pathogens and then activates the proinflammatory cytokines IL-1 and IL-18. While virus-infected airway epithelia often activate NLRP3 inflammasomes,studies to date suggest that these viruses kill the airway epithelial cells via the apoptotic or necrotic pathway; involvement of the pyroptosis pathway has not been reported previously. Here,we show for the first time that virus infection of human airway epithelia can also induce pyroptosis. Human bocavirus 1 (HBoV1),a human parvovirus,causes lower respiratory tract infections in young children. This study indicates that HBoV1 kills airway epithelial cells by activating genes that suppress apoptosis and thereby promote pyroptosis. This strategy appears to promote HBoV1 replication and may have evolved to allow HBoV1 to establish persistent infection of human airway epithelia. View Publication

BACKGROUND Accumulating evidence suggests that some long noncoding RNAs (lncRNAs) are involved in certain diseases,such as cancer. The lncRNA,CCDC26,is related to childhood acute myeloid leukemia (AML) because its copy number is altered in AML patients. RESULTS We found that CCDC26 transcripts were abundant in the nuclear fraction of K562 human myeloid leukemia cells. To examine the function of CCDC26,gene knockdown (KD) was performed using short hairpin RNAs (shRNAs),and four KD clones,in which CCDC26 expression was suppressed to 1% of its normal level,were isolated. This down-regulation included suppression of CCDC26 intron-containing transcripts (the CCDC26 precursor mRNA),indicating that transcriptional gene suppression (TGS),not post-transcriptional suppression,was occurring. The shRNA targeting one of the two CCDC26 splice variants also suppressed the other splice variant,which is further evidence for TGS. Growth rates of KD clones were reduced compared with non-KD control cells in media containing normal or high serum concentrations. In contrast,enhanced growth rates in media containing much lower serum concentrations and increased survival periods after serum withdrawal were observed for KD clones. DNA microarray and quantitative polymerase chain reaction screening for differentially expressed genes between KD clones and non-KD control cells revealed significant up-regulation of the tyrosine kinase receptor,KIT,hyperactive mutations of which are often found in AML. Treatment of KD clones with ISCK03,a KIT-specific inhibitor,eliminated the increased survival of KD clones in the absence of serum. CONCLUSIONS We suggest that CCDC26 controls growth of myeloid leukemia cells through regulation of KIT expression. A KIT inhibitor might be an effective treatment against the forms of AML in which CCDC26 is altered. View Publication

Current anticancer therapies cannot eliminate all cancer cells,which hijack normal arginine methylation as a means to promote their maintenance via unknown mechanisms. Here we show that targeting protein arginine N -methyltransferase 9 (PRMT9),whose activities are elevated in blasts and leukemia stem cells (LSCs) from patients with acute myeloid leukemia (AML),eliminates disease via cancer-intrinsic mechanisms and cancer-extrinsic type I interferon (IFN)-associated immunity. PRMT9 ablation in AML cells decreased the arginine methylation of regulators of RNA translation and the DNA damage response,suppressing cell survival. Notably,PRMT9 inhibition promoted DNA damage and activated cyclic GMP-AMP synthase,which underlies the type I IFN response. Genetically activating cyclic GMP-AMP synthase in AML cells blocked leukemogenesis. We also report synergy of a PRMT9 inhibitor with anti-programmed cell death protein 1 in eradicating AML. Overall,we conclude that PRMT9 functions in survival and immune evasion of both LSCs and non-LSCs; targeting PRMT9 may represent a potential anticancer strategy. Subject terms: Cancer,Tumour immunology View Publication

Enhanced glycolysis plays a pivotal role in fueling the aberrant proliferation,survival and therapy resistance of acute myeloid leukemia (AML) cells. Here,we aimed to elucidate the extent of glycolysis dependence in AML by focusing on the role of lactate dehydrogenase A (LDHA),a key glycolytic enzyme converting pyruvate to lactate coupled with the recycling of NAD + . We compared the glycolytic activity of primary AML patient samples to protein levels of metabolic enzymes involved in central carbon metabolism including glycolysis,glutaminolysis and the tricarboxylic acid cycle. To evaluate the therapeutic potential of targeting glycolysis in AML,we treated AML primary patient samples and cell lines with pharmacological inhibitors of LDHA and monitored cell viability. Glycolytic activity and mitochondrial oxygen consumption were analyzed in AML patient samples and cell lines post-LDHA inhibition. Perturbations in global metabolite levels and redox balance upon LDHA inhibition in AML cells were determined by mass spectrometry,and ROS levels were measured by flow cytometry. Among metabolic enzymes,we found that LDHA protein levels had the strongest positive correlation with glycolysis in AML patient cells. Blocking LDHA activity resulted in a strong growth inhibition and cell death induction in AML cell lines and primary patient samples,while healthy hematopoietic stem and progenitor cells remained unaffected. Investigation of the underlying mechanisms showed that LDHA inhibition reduces glycolytic activity,lowers levels of glycolytic intermediates,decreases the cellular NAD + pool,boosts OXPHOS activity and increases ROS levels. This increase in ROS levels was however not linked to the observed AML cell death. Instead,we found that LDHA is essential to maintain a correct NAD + /NADH ratio in AML cells. Continuous intracellular NAD + supplementation via overexpression of water-forming NADH oxidase from Lactobacillus brevis in AML cells effectively increased viable cell counts and prevented cell death upon LDHA inhibition. Collectively,our results demonstrate that AML cells critically depend on LDHA to maintain an adequate NAD + /NADH balance in support of their abnormal glycolytic activity and biosynthetic demands,which cannot be compensated for by other cellular NAD + recycling systems. These findings also highlight LDHA inhibition as a promising metabolic strategy to eradicate leukemic cells. The online version contains supplementary material available at 10.1186/s40170-025-00392-4. View Publication

The present study focused on the culture medium of induced pluripotent stem cells (iPSCs) prior to the use of cardiomyocytes differentiation induction medium (pre-culture medium). Seven types (Nos. 1-7) of StemFit AK03 medium (Ajinomoto) for clinical iPSCs with varying compositions were prepared as pre-culture medium. The cardiac muscle troponin T (cTnT) positivity of No. 1 (StemFit AK03 medium) was 84%,No. 3 (similar to E8 medium) was 89%,No. 2 (similar to E8 medium) was 91%,No. 5 (similar to EB Formation medium) was 95%,when using differentiation induction medium prepared with known components available for clinical cell production. The formation of cardiac tissues was assessed by evaluating the expression levels of specific markers,including cTnT,atrial natriuretic peptides (ANP),and pro-B-type natriuretic peptide (proBNP). The results demonstrated that cardiac tissue with high protein expression levels of cTnT and ANP was formed when similar to E8 medium as pre-culture medium. The online version contains supplementary material available at 10.1038/s41598-025-13259-x. View Publication