搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Electrospun scaffolds with varied stiffness promote distinct colony morphology of human induced pluripotent stem cells,which affects their subsequent differentiation. On soft scaffolds,induced pluripotent stem cells develop 3D colonies due to the pliability of the electrospun fibrous networks,leading to greater differentiation tendency to ectodermal lineage. View Publication

Mechanisms determining intrinsic differentiation bias inherent to human pluripotent stem cells (hPSCs) toward cardiogenic fate remain elusive. We evaluated the interplay between ErbB4 and EGFR in determining cardiac differentiation in vitro as these receptor tyrosine kinases (RTKs) are key to heart and brain development in vivo. Our results demonstrate that during cardiac differentiation,cell fate biases exist in hPSCs due to cardiac/neuroectoderm divergence post cardiac mesoderm stage. Stage-specific up-regulation of EGFR in concert with persistent Wnt3a signaling post cardiac mesoderm favors commitment towards neural progenitor cells (NPCs). Inhibition of EGFR abrogates these effects with enhanced (textgreater2-fold) cardiac differentiation efficiencies by increasing proliferation of Nkx2-5 expressing cardiac progenitors while reducing proliferation of Sox2 expressing NPCs. Forced overexpression of ErbB4 rescued cardiac commitment by augmenting Wnt11 signaling. Convergence between EGFR/ErbB4 and canonical/non-canonical Wnt signaling determines cardiogenic fate in hPSCs. This article is protected by copyright. All rights reserved. View Publication

Associations between chronic antigen stimulation,T cell dysfunction,and the expression of various inhibitory receptors are well characterized in several mouse and human systems. During chronic hepatitis B virus (HBV) infection (CHB),T cell responses are blunted with low frequencies of virus-specific T cells observed,making these parameters difficult to study. Here,using mass cytometry and a highly multiplexed combinatorial peptide-major histocompatibility complex (pMHC) tetramer strategy that allows for the detection of rare antigen-specific T cells,we simultaneously probed 484 unique HLA-A*1101-restricted epitopes spanning the entire HBV genome on T cells from patients at various stages of CHB. Numerous HBV-specific T cell populations were detected,validated,and profiled. T cells specific for two epitopes (HBVpol387 and HBVcore169) displayed differing and complex heterogeneities that were associated with the disease progression,and the expression of inhibitory receptors on these cells was not linearly related with their extent of T cell dysfunction. For HBVcore169-specific CD8+ T cells,we found cellular markers associated with long-term memory,polyfunctionality,and the presence of several previously unidentified public TCR clones that correlated with viral control. Using high-dimensional trajectory analysis of these cellular phenotypes,a pseudo-time metric was constructed that fit with the status of viral infection in corresponding patients. This was validated in a longitudinal cohort of patients undergoing antiviral therapy. Our study uncovers complex relationships of inhibitory receptors between the profiles of antigen-specific T cells and the status of CHB with implications for new strategies of therapeutic intervention. View Publication

Pluripotent stem cells possess a unique nuclear architecture characterized by a larger nucleus and more open chromatin,which underpins their ability to self-renew and differentiate. Here,we show that the nucleolus-specific RNA helicase DDX18 is essential for maintaining the pluripotency of human embryonic stem cells. Using techniques such as Hi-C,DNA/RNA-FISH,and biomolecular condensate analysis,we demonstrate that DDX18 regulates nucleolus phase separation and nuclear organization by interacting with NPM1 in the granular nucleolar component,driven by specific nucleolar RNAs. Loss of DDX18 disrupts nucleolar substructures,impairing centromere clustering and perinucleolar heterochromatin (PNH) formation. To probe this further,we develop NoCasDrop,a tool enabling precise nucleolar targeting and controlled liquid condensation,which restores centromere clustering and PNH integrity while modulating developmental gene expression. This study reveals how nucleolar phase separation dynamics govern chromatin organization and cell fate,offering fresh insights into the molecular regulation of stem cell pluripotency. Pluripotent stem cells depend on specialized nuclear organization for their function. Here,the authors show that DDX18 regulates nucleolar phase separation and chromatin architecture to preserve human embryonic stem cell pluripotency. View Publication

SummaryGABAergic interneurons are inhibitory neurons of the CNS,playing a fundamental role in neural circuitry and activity. Here,we provide a robust protocol for the successful enrichment of human cerebellar GABAergic interneurons from human induced pluripotent stem cells (iPSCs) and measuring intracellular calcium transients. We describe in detail steps for culturing iPSCs; generating embryoid bodies; and differentiating and enriching for cerebellar GABAergic neurons (cGNs),with precise steps for their molecular characterization. We then detail the procedure for adeno-associated virus-mediated transduction of cGNs with genetically encoded calcium indicators,followed by intracellular calcium imaging and analyses.For complete details on the use and execution of this protocol,please refer to Pilotto et al.1 Graphical abstract Highlights•Steps described for generating GABAergic neurons from human iPSCs•Instructions for the enrichment of cerebellar GABAergic interneurons (cGNs)•Guide to calcium imaging of cGNs using genetically encoded calcium indicators Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics. GABAergic interneurons are inhibitory neurons of the CNS,playing a fundamental role in neural circuitry and activity. Here,we provide a robust protocol for the successful enrichment of human-cerebellar GABAergic interneurons from human induced pluripotent stem cells (iPSCs) and measuring intracellular calcium transients. We describe in detail steps for culturing iPSCs,and generating embryoid bodies,differentiating and enriching for cerebellar GABAergic neurons (cGNs),with precise steps for their molecular characterization. We then detail the procedure for adeno-associated virus-mediated transduction of cGNs with genetically encoded calcium indicators,followed by intracellular calcium imaging and analyses. View Publication

Prime editing (PE) is a CRISPR-based tool for genome engineering that can be applied to generate human induced pluripotent stem cell (hiPSC)-based disease models. PE technology safely introduces point mutations,small insertions,and deletions (indels) into the genome. It uses a Cas9-nickase (nCas9) fused to a reverse transcriptase (RT) as an editor and a PE guide RNA (pegRNA),which introduces the desired edit with great precision without creating double-strand breaks (DSBs). PE leads to minimal off-targets or indels when introducing single-strand breaks (SSB) in the DNA. Low efficiency can be an obstacle to its use in hiPSCs,especially when the genetic context precludes the screening of multiple pegRNAs,and other strategies must be employed to achieve the desired edit. We developed a PE platform to efficiently generate isogenic models of Mendelian disorders. We introduced the c.25G>A (p.V9M) mutation in the NMNAT1 gene with over 25% efficiency by optimizing the PE workflow. Using our optimized system,we generated other isogenic models of inherited retinal diseases (IRDs),including the c.1481C>T (p.T494M) mutation in PRPF3 and the c.6926A>C (p.H2309P) mutation in PRPF8. We modified several determinants of the hiPSC PE procedure,such as plasmid concentrations,PE component ratios,and delivery method settings,showing that our improved workflow increased the hiPSC editing efficiency. View Publication

IntroductionHeme oxygenase-1 (HO-1) is a stress-inducible heat shock protein (HSP32) that exerts cytoprotective effects against oxidative stress and inflammation,and is involved in the maintenance of cellular homeostasis. This study aimed to evaluate the expression of HO-1 in natural killer (NK) cells from individuals of different age groups after stimulation with various factors,and to analyze the relationships between the concentration of this cytoprotective protein and parameters corresponding to oxidative stress and inflammation,that is,NOD-like receptor protein 3 (NLRP3),glutathione (GSH),GSH disulfide (GSSG),and interleukin 6 (IL-6).MethodsThe study population comprised three age groups: young adults (age range,19–23 years),older adults aged under 85 years (age range,73–84 years),and older adults aged over 85 years (age range,85–92 years). NLRP3,GSH,and GSSG concentrations were measured in serum,whereas the HO-1 concentration and IL-6 expression were studied in NK cells cultivated for 48 h and stimulated with IL-2,lipopolysaccharide (LPS),or phorbol 12-myristate 13-acetate (PMA) with ionomycin.ResultsThe analysis of serum NLRP3,GSH,and GSSG concentrations revealed no statistically significant differences among the studied age groups. However,some typical trends of aging were observed,such as a decrease in GSH concentration and an increase in both GSSG level,and GSSG/GSH ratio. The highest basal expression of IL-6 and lowest basal content of HO-1 were found in NK cells of adults over 85 years of age. The NK cells in this age group also showed the highest sensitivity to stimulation with the applied factors. Moreover,statistically significant negative correlations were observed between HO-1 and IL-6 expression levels in the studied NK cells.ConclusionsThese results showed that NK cells can express HO-1 at a basal level,which was significantly increased in activated cells,even in the oldest group of adults. The reciprocal relationship between HO-1 and IL-6 expression suggests a negative feedback loop between these parameters. View Publication

Human T-cell leukemia virus type 1 (HTLV-1) and HTLV-2 are highly related viruses that differ in disease manifestation. HTLV-1 is the etiologic agent of adult T-cell leukemia and lymphoma,an aggressive clonal malignancy of human CD4-bearing T lymphocytes. Infection with HTLV-2 has not been conclusively linked to lymphoproliferative disorders. We previously showed that human hematopoietic progenitor (CD34(+)) cells can be infected by HTLV-1 and that proviral sequences were maintained after differentiation of infected CD34(+) cells in vitro and in vivo. To investigate the role of the Tax oncoprotein of HTLV on hematopoiesis,bicistronic lentiviral vectors were constructed encoding the HTLV-1 or HTLV-2 tax genes (Tax1 and Tax2,respectively) and the green fluorescent protein marker gene. Human hematopoietic progenitor (CD34(+)) cells were infected with lentivirus vectors,and transduced cells were cultured in a semisolid medium permissive for the development of erythroid,myeloid,and primitive progenitor colonies. Tax1-transduced CD34(+) cells displayed a two- to fivefold reduction in the total number of hematopoietic clonogenic colonies that arose in vitro,in contrast to Tax2-transduced cells,which showed no perturbation of hematopoiesis. The ratio of colony types that developed from Tax1-transduced CD34(+) cells remained unaffected,suggesting that Tax1 inhibited the maturation of relatively early,uncommitted hematopoietic stem cells. Since previous reports have linked Tax1 expression with initiation of apoptosis,lentiviral vector-mediated transduction of Tax1 or Tax2 was investigated in CEM and Jurkat T-cell lines. Ectopic expression of either Tax1 or Tax2 failed to induce apoptosis in T-cell lines. These data demonstrate that Tax1 expression perturbs development and maturation of pluripotent hematopoietic progenitor cells,an activity that is not displayed by Tax2,and that the suppression of hematopoiesis is not attributable to induction of apoptosis. Since hematopoietic progenitor cells may serve as a latently infected reservoir for HTLV infection in vivo,the different abilities of HTLV-1 and -2 Tax to suppress hematopoiesis may play a role in the respective clinical outcomes after infection with HTLV-1 or -2. View Publication

We used a panel of human and mouse fibroblasts with various abilities for supporting the prolonged growth of human embryonic stem cells (hESCs) to elucidate growth factors required for hESC survival,proliferation,and maintenance of the undifferentiated and pluripotent state (self-renewal). We found that supportive feeder cells secrete growth factors required for both hESC survival/proliferation and blocking hESC spontaneous differentiation to achieve self-renewal. The antidifferentiation soluble factor is neither leukemia inhibitory factor nor Wnt,based on blocking experiments using their antagonists. Because Wnt/beta-catenin signaling has been implicated in cell-fate determination and stem cell expansion,we further examined the effects of blocking or adding recombinant Wnt proteins on undifferentiated hESCs. In the absence of feeder cell-derived factors,hESCs cultured under a feeder-free condition survived/proliferated poorly and gradually differentiated. Adding recombinant Wnt3a stimulated hESC proliferation but also differentiation. After 4-5 days of Wnt3a treatment,hESCs that survived maintained the undifferentiated phenotype but few could form undifferentiated hESC colonies subsequently. Using a functional reporter assay,we found that the beta-catenin-mediated transcriptional activation in the canonical Wnt pathway was minimal in undifferentiated hESCs,but greatly upregulated during differentiation induced by the Wnt treatment and several other methods. Thus,Wnt/beta-catenin activation does not suffice to maintain the undifferentiated and pluripotent state of hESCs. We propose a new model for the role of Wnt/beta-catenin signaling in undifferentiated hESCs. View Publication

Cell replacement therapy is a promising approach for the treatment of cardiac diseases. It is,however,challenged by a limited supply of appropriate cells. Therefore,we have investigated whether functional cardiomyocytes can be efficiently generated from human embryonic stem cells (hESCs). In this study,we developed an efficient protocol for the generation of functional cardiomyocytes from hESCs by combining hanging drop culture and 5-azacytidine,a well-known demethylating agent,and then evaluated the expression of cardiac-specific markers. hESCs were cultured both in the medium without or with 0.1,1,or 10 microM of 5-azacytidine under a hanging drop culture. The expression of several cardiac-specific markers was determined by real-time PCR,RT-PCR,immunofluorescence,and confocal microscopy. To verify the structural and functional properties of hESC-derived cardiomyocytes,we performed electron microscopy and electrophysiological recording. The efficiency of beating cell generation was significantly improved in the hanging drop culture compared with that in suspension culture. Treatment of hESCs with 0.1 microM of 5-azacytidine for 1-3 days significantly increased the number of beating cells and simultaneously enhanced the expression of cardiac-specific markers. Transmission electron microscopy and electrophysiological recording showed that hESC-derived cardiomyocytes acquired structural and functional properties of cardiomyocytes. In conclusion,these results suggest that differentiation of hESCs into cardiomyocytes can be enhanced by the combination of hanging drop culture and 5-azacytidine treatment. Also the methylation status of genes related to cardiomyocyte development may play an important role in the differentiation of hESCs into cardiomyocytes. View Publication

Abnormal activation of B lymphocytes is a feature commonly seen in human immunodeficiency virus type 1 (HIV-1)-infected persons. However,the mechanism(s) responsible for this dysfunction is still poorly understood. Having recently shown that CD40L,the ligand for CD40,is inserted within emerging HIV-1 particles,we hypothesized that the contact between virus-anchored host CD40L and CD40 on the surface of B lymphocytes might result in the activation of this cell type. We report here that CD40L-bearing viruses,but not isogenic virions lacking host-derived CD40L,can induce immunoglobulin G and interleukin-6 production. Furthermore,such viral entities were found to induce B-cell homotypic adhesion. These effects were paralleled at the intracellular level by the nuclear translocation of the ubiquitous transcription factor NF-kappaB. The presence of host-derived CD40L within virions resulted in an increased virus attachment to B cells and a more-efficient B-cell-mediated transfer of HIV-1 to autologous CD4(+) T lymphocytes. All the above processes were independent of the virus-encoded envelope glycoproteins. Altogether,the data gathered from this series of investigations suggest that the incorporation of host-encoded CD40L in HIV-1 is likely to play a role in the B-cell abnormalities that are seen in infected individuals. View Publication

Human urine cells (HUCs) can be reprogrammed into neural progenitor cells (NPCs) or induced pluripotent stem cells (iPSCs) with defined factors and a small molecule cocktail,but the underlying fate choice remains unresolved. Here,through sequential removal of individual compound from small molecule cocktail,we showed that A8301,a TGF$$ signaling inhibitor,is sufficient to switch the cell fate from iPSCs into NPCs in OSKM-mediated HUCs reprogramming. However,TGF$$ exposure at early stage inhibits HUCs reprogramming by promoting EMT. Base on these data,we developed an optimized approach for generation of NPCs or iPSCs from HUCs with significantly improved efficiency by regulating TGF$$ activity at different reprogramming stages. This approach provides a simplified and improved way for HUCs reprogramming,thus would be valuable for banking human iPSCs or NPCs from people with different genetic background. View Publication