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

In this study,we sought to establish a novel method to prospectively and dynamically identify live human oligodendrocyte precursor cells (OPCs) and oligodendrocyte lineage cells from brain dissociates and pluripotent stem cell culture. We selected a highly conserved enhancer element of the Sox10 gene,known as MCS5,which directs reporter expression to oligodendrocyte lineage cells in mouse and zebrafish. We demonstrate that lentiviral Sox10-MCS5 induced expression of GFP at high levels in a subpopulation of human CD140a/PDGF??R-sorted OPCs as well as their immature oligodendrocyte progeny. Furthermore,we show that almost all Sox10-MCS5:GFPhigh cells expressed OPC antigen CD140a and human OPCs expressing SOX10,OLIG2,and PDGFRA mRNAs could be prospectively identified using GFP based fluorescence activated cells sorting alone. Additionally,we established a human induced pluripotent cell (iPSC) line transduced with the Sox10-MCS5:GFP reporter using a Rex-Neo cassette. Similar to human primary cells,GFP expression was restricted to embryoid bodies containing both oligodendrocyte progenitor and oligodendrocyte cells and co-localized with NG2 and O4-positive cells respectively. As such,we have developed a novel reporter system that can track oligodendrocyte commitment in human cells,establishing a valuable tool to improve our understanding and efficiency of human oligodendrocyte derivation. ?? 2013 Elsevier Inc. View Publication

In mammals,early embryonic gastrulation process is high energy demanding. Previous studies showed that,unlike endoderm and mesoderm cells,neuroectoderm differentiated from human embryonic stem cells relied on aerobic glycolysis as the major energy metabolic process,which generates lactate as the final product. Here we explored the function of intracellular lactate during neuroectoderm differentiation. Our results revealed that the intracellular lactate level was elevated in neuroectoderm and exogenous lactate could further promote hESCs differentiation towards neuroectoderm. Changing intracellular lactate levels by sodium lactate or LDHA inhibitors had no obvious effect on BMP or WNT/?-catenin signaling during neuroectoderm differentiation. Notably,histone lactylation,especially H3K18 lactylation was significant upregulated during this process. We further performed CUT&Tag experiments and the results showed that H3K18la is highly enriched at gene promoter regions. By analyzing data from CUT&Tag and RNA-seq experiments,we further identified that four genes,including PAX6,were transcriptionally upregulated by lactate during neuroectoderm differentiation. A H3K18la modification site at PAX6 promoter was verified and exogenous lactate could also rescue the level of PAX6 after shPAX6 inhibition.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00018-024-05510-x. View Publication

We have studied the mechanism of A-769662,a new activator of AMP-activated protein kinase (AMPK). Unlike other pharmacological activators,it directly activates native rat AMPK by mimicking both effects of AMP,i.e. allosteric activation and inhibition of dephosphorylation. We found that it has no effect on the isolated alpha subunit kinase domain,with or without the associated autoinhibitory domain,or on interaction of glycogen with the beta subunit glycogen-binding domain. Although it mimics actions of AMP,it has no effect on binding of AMP to the isolated Bateman domains of the gamma subunit. The addition of A-769662 to mouse embryonic fibroblasts or primary mouse hepatocytes stimulates phosphorylation of acetyl-CoA carboxylase (ACC),effects that are completely abolished in AMPK-alpha1(-/-)alpha2(-/-) cells but not in TAK1(-/-) mouse embryonic fibroblasts. Phosphorylation of AMPK and ACC in response to A-769662 is also abolished in isolated mouse skeletal muscle lacking LKB1,a major upstream kinase for AMPK in this tissue. However,in HeLa cells,which lack LKB1 but express the alternate upstream kinase calmodulin-dependent protein kinase kinase-beta,phosphorylation of AMPK and ACC in response to A-769662 still occurs. These results show that in intact cells,the effects of A-769662 are independent of the upstream kinase utilized. We propose that this direct and specific AMPK activator will be a valuable experimental tool to understand the physiological roles of AMPK. 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

Efficient allocation of deceased donor organs depends upon effective prediction of immunologic compatibility based on donor HLA genotype and recipient alloantibody profile,referred to as virtual crossmatching (VCXM). VCXM has demonstrated utility in predicting compatibility,though there is reduced efficacy for patients highly sensitized against allogeneic HLA antigens. The recently revised deceased donor kidney allocation system (KAS) has increased transplantation for this group,but with an increased burden for histocompatibility testing and organ sharing. Given the limitations of VCXM,we hypothesized that increased organ offers for highly-sensitized patients could result in a concomitant increase in offers rejected due to unexpectedly positive crossmatch. Review of 645 crossmatches performed for deceased donor kidney transplantation at our center did not reveal a significant increase in positive crossmatches following KAS implementation. Positive crossmatches not predicted by VCXM were concentrated among highly-sensitized patients. Root cause analysis of VCXM failures identified technical limitations of anti-HLA antibody testing as the most significant contributor to VCXM error. Contributions of technical limitations including additive/synergistic antibody effects,prozone phenomenon,and antigens not represented in standard testing panels,were evaluated by retrospective testing. These data provide insight into the limitations of VCXM,particularly those affecting allocation of kidneys to highly-sensitized patients. View Publication

Cardiomyocytes (CM) derived from human embryonic stem cells (hESC) are used for cardio-toxicity evaluation and tested in many preclinical trials for their potential use in regenerative therapeutics. As more efficient CM differentiation protocols are developed,reliable automated platforms for characterization and detection are needed. An automated time-resolved video analysis and management system (TVAMS) has been developed for the evaluation of hESC differentiation to CM. The system was used for monitoring the kinetics of embryoid bodies (EB) generation (numbers and size) and differentiation into beating EBs (percentage beating area and beating EB count) in two differentiation protocols. We show that the percentage beating areas of EBs (from total area of the EBs) is a more sensitive and better predictor of CM differentiation efficiency than percentage of beating EBs (from total EBs) as the percentage beating areas of EBs correlates with cardiac troponin-T and myosin heavy chain expression levels. TVAMS can also be used to evaluate the effect of drugs and inhibitors (e.g. isoproterenol and ZD7288) on CM beating frequency. TVAMS can reliably replace the commonly practiced,time consuming,manual counting of total and beating EBs during CM differentiation. TVAMS is a high-throughput non-invasive video imaging platform that can be applied for the development of new CM differentiation protocols,as well as a tool to conduct CM toxicology assays. View Publication

The administration of antiretroviral therapy (ART) leads to a rapid reduction in plasma viral load in HIV-1 seropositive subjects. However,when ART is suspended,the virus rebounds due to the presence of a latent viral reservoir. Several techniques have been developed to characterize this latent viral reservoir. Of the various assay formats available presently,the Tat/Rev induced limiting dilution assay (TILDA) offers the most robust and technically simple assay strategy. The TILDA formats reported thus far are limited by being selective to one or a few HIV-1 genetic subtypes,thus,restricting them from a broader level application. The novel TILDA,labelled as U-TILDA ('U' for universal),can detect all the major genetic subtypes of HIV-1 unbiasedly,and with comparable sensitivity of detection. U-TILDA is well suited to characterize the latent reservoirs of HIV-1 and aid in the formulation of cure strategies. Graphical abstract. View Publication

Monoclonal antibodies are at the vanguard of the most promising cancer treatments. Whereas traditional therapeutic antibodies have been limited to extracellular antigens,T cell receptor mimic (TCRm) antibodies can target intracellular antigens presented by cell surface major histocompatibility complex (MHC) proteins. TCRm antibodies can therefore target a repertoire of otherwise undruggable cancer antigens. However,the consequences of off-target peptide/MHC recognition with engineered T cell therapies are severe,and thus there are significant safety concerns with TCRm antibodies. Here we explored the specificity and safety profile of a new TCRm-based T cell therapy for hepatocellular carcinoma (HCC),a solid tumor for which no effective treatment exists. We targeted an alpha-fetoprotein peptide presented by HLA-A*02 with a highly specific TCRm,which crystallographic structural analysis showed binds directly over the HLA protein and interfaces with the full length of the peptide. We fused the TCRm to the ? and ? subunits of a TCR,producing a signaling AbTCR construct. This was combined with an scFv/CD28 co-stimulatory molecule targeting glypican-3 for increased efficacy towards tumor cells. This AbTC + co-stimulatory T cell therapy showed potent activity against AFP-positive cancer cell lines in vitro and an in an in vivo model and undetectable activity against AFP-negative cells. In an in-human safety assessment,no significant adverse events or cytokine release syndrome were observed and evidence of efficacy was seen. Remarkably,one patient with metastatic HCC achieved a complete remission after nine months and ultimately qualified for a liver transplant. View Publication

Hydrogen Peroxide (H2O2) is a central oxidant in redox biology due to its pleiotropic role in physiology and pathology. However,real-time monitoring of H2O2 in living cells and tissues remains a challenge. We address this gap with the development of an optogenetic hydRogen perOxide Sensor (oROS),leveraging the bacterial peroxide binding domain OxyR. Previously engineered OxyR-based fluorescent peroxide sensors lack the necessary sensitivity and response speed for effective real-time monitoring. By structurally redesigning the fusion of Escherichia coli (E. coli) ecOxyR with a circularly permutated green fluorescent protein (cpGFP),we created a novel,green-fluorescent peroxide sensor oROS-G. oROS-G exhibits high sensitivity and fast on-and-off kinetics,ideal for monitoring intracellular H2O2 dynamics. We successfully tracked real-time transient and steady-state H2O2 levels in diverse biological systems,including human stem cell-derived neurons and cardiomyocytes,primary neurons and astrocytes,and mouse brain ex vivo and in vivo. These applications demonstrate oROS’s capabilities to monitor H2O2 as a secondary response to pharmacologically induced oxidative stress and when adapting to varying metabolic stress. We showcased the increased oxidative stress in astrocytes via A?-putriscine-MAOB axis,highlighting the sensor’s relevance in validating neurodegenerative disease models. Lastly,we demonstrated acute opioid-induced generation of H2O2 signal in vivo which highlights redox-based mechanisms of GPCR regulation. oROS is a versatile tool,offering a window into the dynamic landscape of H2O2 signaling. This advancement paves the way for a deeper understanding of redox physiology,with significant implications for understanding diseases associated with oxidative stress,such as cancer,neurodegenerative,and cardiovascular diseases. View Publication

Ex vivo cellular system that accurately replicates sickle cell disease and β-thalassemia characteristics is a highly sought-after goal in the field of erythroid biology. In this study,we present the generation of erythroid progenitor lines with sickle cell disease and β-thalassemia mutation using CRISPR/Cas9. The disease cellular models exhibit similar differentiation profiles,globin expression and proteome dynamics as patient-derived hematopoietic stem/progenitor cells. Additionally,these cellular models recapitulate pathological conditions associated with both the diseases. Hydroxyurea and pomalidomide treatment enhanced fetal hemoglobin levels. Notably,we introduce a therapeutic strategy for the above diseases by recapitulating the HPFH3 genotype,which reactivates fetal hemoglobin levels and rescues the disease phenotypes,thus making these lines a valuable platform for studying and developing new therapeutic strategies. Altogether,we demonstrate our disease cellular systems are physiologically relevant and could prove to be indispensable tools for disease modeling,drug screenings and cell and gene therapy-based applications. Sickle cell disease (SCD) and β-thalassemia (BT) are globally prevalent inherited blood disorders but,despite extensive research,no ex vivo system exists for SCD and BT. Here,the authors generate pathophysiologically relevant erythroid progenitor models of SCD and BT. View Publication

AbstractThere is currently a lack of tools capable of perturbing genes in both a precise and a spatiotemporal fashion. The flexibility of CRISPR (clustered regularly interspaced short palindromic repeats),coupled with light’s unparalleled spatiotemporal resolution deliverable from a controllable source,makes optogenetic CRISPR a well-suited solution for precise spatiotemporal gene perturbations. Here,we present a new optogenetic CRISPR tool (Blue Light-inducible Universal VPR-Improved Production of RGRs,BLU-VIPR) that diverges from prevailing split-Cas design strategies and instead focuses on optogenetic regulation of guide RNA (gRNA) production. We engineered BLU-VIPR around a new potent blue-light activated transcription factor (VPR-EL222) and ribozyme-flanked gRNA. The BLU-VIPR design is genetically encoded and ensures precise excision of multiple gRNAs from a single messenger RNA transcript. This simplified spatiotemporal gene perturbation and allowed for several types of optogenetic CRISPR,including indels,CRISPRa,and base editing. BLU-VIPR also worked in vivo with cells previously intractable to optogenetic gene editing,achieving optogenetic gene editing in T lymphocytes in vivo. View Publication