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

Homology Directed Repair (HDR) enables precise genome editing,but the implementation of HDR-based therapies is hindered by limited efficiency in comparison to methods that exploit alternative DNA repair routes,such as Non-Homologous End Joining (NHEJ). In this study,we develop a functional,pooled screening platform to identify protein-based reagents that improve HDR in human hematopoietic stem and progenitor cells (HSPCs). We leverage this screening platform to explore sequence diversity at the binding interface of the NHEJ inhibitor i53 and its target,53BP1,identifying optimized variants that enable new intermolecular bonds and robustly increase HDR. We show that these variants specifically reduce insertion-deletion outcomes without increasing off-target editing,synergize with a DNAPK inhibitor molecule,and can be applied at manufacturing scale to increase the fraction of cells bearing repaired alleles. This screening platform can enable the discovery of future gene editing reagents that improve HDR outcomes. Subject terms: Targeted gene repair,Homologous recombination,High-throughput screening View Publication

Johnson,Ogishi,and Domingo-Vila et al. describe two siblings with inherited PD-L1 deficiency. Human PD-L1 deficiency underlies early-onset T1D,like PD-1 deficiency,but does not lead to fatal autoimmunity with extensive leukocytic dysregulation,unlike PD-1 deficiency. View Publication

Prenatal nicotine exposure impairs fetal cortical grey matter volume,but the precise cellular mechanisms remain poorly understood. This study elucidates the role of nicotinic acetylcholine receptors (nAChRs) in progenitor cells and radial glia (RG) during human cortical development. We identify two nAChR subunits—CHRNA7 and the human-specific CHRFAM7A—expressed in SOX2+ progenitors and neurons,with CHRFAM7A particularly enriched along RG endfeet. nAChR activation in organotypic slices and dissociated cultures increases RG proliferation while decreasing neuronal differentiation,whereas nAChR knockdown reduces RG and increases neurons. Single-cell RNA sequencing reveals that nicotine exposure downregulates key genes in excitatory neurons (ENs),with CHRNA7 or CHRFAM7A selectively modulating these changes,suggesting an evolutionary divergence in regulatory pathways. Furthermore,we identify YAP1 as a critical downstream effector of nAChR signaling,and inhibiting YAP1 reverses nicotine-induced phenotypic alterations in oRG cells,highlighting its role in nicotine-induced neurodevelopmental pathophysiology. Subject terms: Neuronal development,Developmental neurogenesis,Neural stem cells View Publication

The cerebellum plays a critical role in all vertebrates,and many neurological disorders are associated with cerebellum dysfunction. A major limitation in cerebellar research has been the lack of adequate disease models. As an alternative to animal models,cerebellar neurons differentiated from pluripotent stem cells have been used. However,previous studies only produced limited amounts of Purkinje cells. Moreover,in vitro generation of Purkinje cells required co-culture systems,which may introduce unknown components to the system. Here we describe a novel differentiation strategy that uses defined medium to generate Purkinje cells,granule cells,interneurons,and deep cerebellar nuclei projection neurons,that self-formed and differentiated into electrically active cells. Using a defined basal medium optimized for neuronal cell culture,we successfully promoted the differentiation of cerebellar precursors without the need for co-culturing. We anticipate that our findings may help developing better models for the study of cerebellar dysfunctions,while providing an advance toward the development of autologous replacement strategies for treating cerebellar degenerative diseases. View Publication

The pulmonary system is comprised of two main compartments,airways and alveolar space. Their tissue and cellular complexity ensure lung function and protection from external agents,for example,virus. Two-dimensional (2D) in vitro systems and animal models have been largely employed to elucidate the molecular mechanisms underlying human lung development,physiology,and pathogenesis. However,neither of these models accurately recapitulate the human lung environment and cellular crosstalk. More recently,human-derived three-dimensional (3D) models have been generated allowing for a deeper understanding of cell-to-cell communication. However,the availability and accessibility of primary human cell sources from which generate the 2D and 3D models may be limited. In the past few years,protocols have been developed to successfully employ human pluripotent stem cells (hPSCs) and differentiate them toward pulmonary fate in vitro. In the present review,we discuss the advantages and pitfalls of hPSC-derived lung 2D and 3D models,including the main characteristics and potentials for these models and their current and future applications for modeling development and diseases. Lung organoids currently represent the closest model to the human pulmonary system. We further focus on the applications of lung organoids for the study of human diseases such as pulmonary fibrosis,infectious diseases,and lung cancer. Finally,we discuss the present limitations and potential future applications of 3D lung organoids. This article is categorized under: Adult Stem Cells,Tissue Renewal,and Regeneration {\textgreater} Stem Cells and Disease Adult Stem Cells,Tissue Renewal,and Regeneration {\textgreater} Stem Cell Differentiation and Reversion. View Publication

Cutaneous tuberculosis (CTB) is an infectious disease highly associated with extracellular matrix remodeling and granuloma-driven fibrosis. Fibroblasts play crucial roles in this fibrotic process,but their specific roles in Mycobacterium tuberculosis (Mtb) skin infections remain unclear due to the lack of proper in vitro models. Here,we demonstrate that skin organoids (SKOs) derived from human induced pluripotent stem cells can model CTB infected by Mtb. Single-cell RNA analyses reveal an increase in fibroblasts,upregulation of genes involved in collagen synthesis,and enhanced collagen degradation induced by MMP2 and MMP14 in Mtb-infected SKOs. This is accompanied by the destruction of nerve cells and adipocytes. Importantly,the onset of fibrosis in Mtb-infected SKOs is dependent on the activation of the PI3K-AKT signaling pathway and transcription factor AP1 in fibroblasts. Pharmacological inhibition of PI3K-AKT and AP1 alleviates fibrosis and collagen deposition. Our findings have uncovered distinct alterations in cell populations during Mtb-induced skin fibrosis,highlighting the crucial roles of PI3K-AKT and AP1. The study demonstrates the utility of SKOs for investigating CTB pathogenesis and evaluating potential antifibrotic treatments. Cutaneous tuberculosis is an infectious disease associated with extracellular matrix remodeling and granuloma-driven fibrosis. Here,the authors present an in vitro model of this disease using skin organoids infected with Mycobacterium tuberculosis,and describe infection-induced alterations in specific pathways and cell populations. View Publication

Many receptor-linked agents that prime or activate the NADPH oxidase in polymorphonuclear neutrophils (PMNs) elicit changes in cytosolic Ca2+ concentration and activate mitogen-activated protein (MAP) kinases. To investigate the role of Ca2+ in the activation of p38 and p42/44 MAP kinases,we examined the effects of the Ca2+-selective ionophore ionomycin on priming and activation of the PMN oxidase. Ionomycin caused a rapid rise in cytosolic Ca2+ that was due to both a release of cytosolic Ca2+ stores and Ca2+ influx. Ionomycin also activated (2 microM) and primed (20-200 nM) the PMN oxidase. Dual phosphorylation of p38 MAP kinase and phosphorylation of its substrate activating transcription factor-2 were detected at ionomycin concentrations that prime or activate the PMN oxidase,while dual phosphorylation of p42/44 MAP kinase and phosphorylation of its substrate Elk-1 were elicited at 0.2-2 microM. SB-203580,a p38 MAP kinase antagonist,inhibited ionomycin-induced activation of the oxidase (68 +/- 8%,P textless 0.05) and tyrosine phosphorylation of 105- and 72-kDa proteins; conversely,PD-98059,an inhibitor of MAP/extracellular signal-related kinase 1,had no effect. Treatment of PMNs with thapsigargin resulted in priming of the oxidase and activation of p38 MAP kinase. Chelation of cytosolic but not extracellular Ca2+ completely inhibited ionomycin activation of p38 MAP kinase,whereas chelation of extracellular Ca2+ abrogated activation of p42/44 MAP kinase. These results demonstrate the importance of changes in cytosolic Ca2+ for MAP kinase activation in PMNs. View Publication

The fabrication of high-density polymer microarray is described,allowing the simultaneous and efficient evaluation of more than 7000 different polymers in a single-cellular-based screen. These high-density polymer arrays are applied in the search for synthetic substrates for hESCs culture. Up-scaling of the identified hit polymers enables long-term cellular cultivation and promoted successful stem-cell maintenance. View Publication

Chylomicron remnants (CMRs) contribute directly to human monocyte activation in vitro,by increasing reactive oxygen species (ROS) production and cell migration. In this study,the effects of the oxidative state of CMR on the degree of monocyte activation was investigated. CMR-like particles (CRLPs) were prepared in three different oxidative states,normal (CRLPs),protected from oxidation by incorporation of the antioxidant,probucol (pCRLPs),or oxidised with CuSO(4) (oxCRLPs). Lipid accumulation and ROS production were significantly increased in primary human monocytes incubated with CRLPs,whilst secretion on monocyte chemoattractant protein-1 was reduced,but oxCRLPs had no additional effect. In contrast,pCRLPs were taken up by monocytes to a lesser extent and had no significant effect on ROS or MCP-1 secretion. These studies suggest that the oxidative state of CMRs modulates their stimulation of the activation of peripheral blood human monocytes and that dietary antioxidants may provide some protection against these atherogenic effects. View Publication

HUCB (human umbilical cord blood) has been frequently used in clinical allogeneic HSC (haemopoietic stem cell) transplant. However,HUCB is poorly recognized as a rich source of MSC (mesenchymal stem cell). The aim of this study has been to establish a new method for isolating large number of MSC from HUCB to recognize it as a good source of MSC. HUCB samples were collected from women following their elective caesarean section. The new method (Clot Spot method) was carried out by explanting HUCB samples in mesencult complete medium and maintained in 37°C,in a 5% CO2 and air incubator. MSC presence was established by quantitative and qualitative immunophenotyping of cells and using FITC attached to MSC phenotypic markers (CD29,CD73,CD44 and CD105). Haematopoietic antibodies (CD34 and CD45) were used as negative control. MSC differentiation was examined in neurogenic and adipogenic media. Immunocytochemistry was carried out for the embryonic markers: SOX2 (sex determining region Y-box 2),OLIG-4 (oligodendrocyte-4) and FABP-4 (fatty acid binding protein-4). The new method was compared with the conventional Rosset Sep method. MSC cultures using the Clot Spot method showed 3-fold increase in proliferation rate compared with conventional method. Also,the cells showed high expression of MSC markers CD29,CD73,CD44 and CD105,but lacked the expression of specific HSC markers (CD34 and CD45). The isolated MSC showed some differentiation by expressing the neurogenic (SOX2 and Olig4) and adipogenic (FABP-4) markers respectively. In conclusion,HUCB is a good source of MSC using this new technique. View Publication

MYCN amplification without concurrent RB1 mutations characterizes a rare yet highly aggressive subtype of retinoblastoma; however,its precise developmental origins and therapeutic vulnerabilities remain incompletely understood. Here,we modeled this subtype by lentiviral-mediated MYCN overexpression in human pluripotent stem cell-derived retinal organoids,revealing a discrete developmental window (days 70–120) during which retinal progenitors showed heightened susceptibility to transformation. Tumors arising in this period exhibited robust proliferation,expressed SOX2,and lacked CRX,consistent with origin from primitive retinal progenitors. MYCN-overexpressing organoids generated stable cell lines that reproducibly gave rise to MYCN-driven tumors when xenografted into immunodeficient mice. Transcriptomic profiling demonstrated that MYCN-overexpressing organoids closely recapitulated molecular features of patient-derived MYCN-amplified retinoblastomas,particularly through activation of MYC/E2F and mTORC1 signaling pathways. Pharmacological screening further identified distinct therapeutic vulnerabilities,demonstrating distinct subtype-specific sensitivity of MYCN-driven cells to transcriptional inhibitors (THZ1,Flavopiridol) and the cell-cycle inhibitor Volasertib,indicative of a unique oncogene-addicted state compared to RB1-deficient retinoblastoma cells. Collectively,our study elucidates the developmental and molecular mechanisms underpinning MYCN-driven retinoblastoma,establishes a robust and clinically relevant human retinal organoid platform,and highlights targeted transcriptional inhibition as a promising therapeutic approach for this aggressive pediatric cancer subtype. View Publication

Solar ultraviolet (sUV) exposure is known to cause skin damage. However,the pathological mechanisms of sUV on hair follicles have not been extensively explored. Here,we established a model of sUV-exposed skin and its appendages using human induced pluripotent stem cell-derived skin organoids with planar morphology containing hair follicles. Our model closely recapitulated several symptoms of photodamage,including skin barrier disruption,extracellular matrix degradation,and inflammatory response. Specifically,sUV induced structural damage and catagenic transition in hair follicles. As a potential therapeutic agent for hair follicles,we applied exosomes isolated from human umbilical cord blood-derived mesenchymal stem cells to sUV-exposed organoids. As a result,exosomes effectively alleviated inflammatory responses by inhibiting NF-κB activation,thereby suppressing structural damage and promoting hair follicle regeneration. Ultimately,our model provided a valuable platform to mimic skin diseases,particularly those involving hair follicles,and to evaluate the efficacy and underlying mechanisms of potential therapeutics. View Publication