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

Magnesium alloys have attracted great interest for medical applications due to their unique biodegradable capability and desirable mechanical properties. When designed for medical applications,these alloys must have suitable degradation properties,i.e.,their degradation rate should not exceed the rate at which the degradation products can be excreted from the body. Cellular responses and tissue integration around the Mg-based implants are critical for clinical success. Four magnesium–zinc–strontium (ZSr41) alloys were developed in this study. The degradation properties of the ZSr41 alloys and their cytocompatibility were studied using an in vitro human embryonic stem cell (hESC) model due to the greater sensitivity of hESCs to known toxicants which allows to potentially detect toxicological effects of new biomaterials at an early stage. Four distinct ZSr41 alloys with 4 wt% zinc and a series of strontium compositions (0.15,0.5,1,and 1.5 wt% Sr) were produced through metallurgical processing. Their degradation was characterized by measuring total mass loss of samples and pH change in the cell culture media. The concentration of Mg ions released from ZSr41 alloy into the cell culture media was analyzed using inductively coupled plasma atomic emission spectroscopy. Surface microstructure and composition before and after culturing with hESCs were characterized using field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. Pure Mg was used as a control during cell culture studies. Results indicated that the Mg–Zn–Sr alloy with 0.15 wt% Sr provided slower degradation and improved cytocompatibility as compared with pure Mg control. View Publication

Organs-on-chips are microengineered in vitro tissue structures that can be used as platforms for physiological and pathological research. They provide tissue-like microenvironments in which different cell types can be co-cultured in a controlled manner to create synthetic organ mimics. Blood vessels are an integral part of all tissues in the human body. Development of vascular structures is therefore an important research topic for advancing the field of organs-on-chips since generated tissues will require a blood or nutrient supply. Here,we have engineered three-dimensional constructs of vascular tissue inside microchannels by injecting a mixture of human umbilical vein endothelial cells,human embryonic stem cell-derived pericytes (the precursors of vascular smooth muscle cells) and rat tail collagen I into a polydimethylsiloxane microfluidic channel with dimensions 500 μm × 120 μm × 1 cm (w × h × l). Over the course of 12 h,the cells organized themselves into a single long tube resembling a blood vessel that followed the contours of the channel. Detailed examination of tube morphology by confocal microscopy revealed a mature endothelial monolayer with complete PECAM-1 staining at cell–cell contacts and pericytes incorporated inside the tubular structures. We also demonstrated that tube formation was disrupted in the presence of a neutralizing antibody against transforming growth factor-beta (TGF-β). The TGF-β signaling pathway is essential for normal vascular development; deletion of any of its components in mouse development results in defective vasculogenesis and angiogenesis and mutations in humans have been linked to multiple vascular genetic diseases. In the engineered microvessels,inhibition of TGF-β signaling resulted in tubes with smaller diameters and higher tortuosity,highly reminiscent of the abnormal vessels observed in patients with one particular vascular disease known as hereditary hemorrhagic telangiectasia (HHT). In summary,we have developed microengineered three-dimensional vascular structures that can be used as a model to test the effects of drugs and study the interaction between different human vascular cell types. In the future,the model may be integrated into larger tissue constructs to advance the development of organs-on-chips. View Publication

Human adipose-derived stem cells (ADSCs) can release exosomes; however,their specific functions remain elusive. In this study,we verified that exosomes derived from osteogenically differentiated ADSCs can promote osteogenic differentiation of ADSCs. Furthermore,in order to investigate the importance of exosomal microRNAs (miRNAs) in osteogenic differentiation of ADSCs,we used microarray assays to analyze the expression profiles of exosomal miRNAs derived from undifferentiated as well as osteogenically differentiated ADSCs; 201 miRNAs were upregulated and 33 miRNAs were downregulated between the two types of exosomes. Additionally,bioinformatic analyses,which included gene ontology analyses,pathway analysis,and miRNA-mRNA-network investigations,were performed. The results of these analyses revealed that the differentially expressed exosomal miRNAs participate in multiple biological processes,such as gene expression,synthesis of biomolecules,cell development,differentiation,and signal transduction,among others. Moreover,we found that these differentially expressed exosomal miRNAs connect osteogenic differentiation to processes such as axon guidance,MAPK signaling,and Wnt signaling. To the best of our knowledge,this is the first study to identify and characterize exosomal miRNAs derived from osteogenically differentiated ADSCs. This study confirms that alterations in the expression of exosomal miRNAs can promote osteogenic differentiation of ADSCs,which also provides the foundation for further research on the regulatory functions of exosomal miRNAs in the context of ADSC osteogenesis. View Publication

Although many previous investigations have studied how mercury compounds cause cell death,sub-cytotoxic levels may affect mechanisms essential for the proper development of the nervous system. The present study investigates whether low doses of methylmercury (MeHg) and mercury chloride (HgCl2) can modulate the activity of JAK/STAT signaling,a pathway that promotes gliogenesis. We report that sub-cytotoxic doses of MeHg enhance ciliary neurotrophic factor (CNTF) evoked STAT3 phosphorylation in human SH-SY5Y neuroblastoma and mouse cortical neural progenitor cells (NPCs). This effect is specific for MeHg,since HgCl2 fails to enhance JAK/STAT signaling. Exposing NPCs to these low doses of MeHg (30-300nM) enhances CNTF-induced expression of STAT3-target genes such as glial fibrillary acidic protein (GFAP) and suppressors of cytokine signaling 3 (SOCS3),and increases the proportion of cells expressing GFAP following 2 days of differentiation. Higher,near-cytotoxic concentrations of MeHg and HgCl2 inhibit STAT3 phosphorylation and lead to increased production of superoxide. Lower concentrations of MeHg effective in enhancing JAK/STAT signaling (30nM) do not result in a detectable increase in superoxide nor increased expression of the oxidant-responsive genes,heme oxygenase 1,heat shock protein A5 and sirtuin 1. These findings suggest that low concentrations of MeHg inappropriately enhance STAT3 phosphorylation and glial differentiation,and that the mechanism causing this enhancement is distinct from the reactive oxygen species-associated cell death observed at higher concentrations of MeHg and HgCl2. View Publication

Immune rejection is one of the most serious challenges in allogeneic transplantation,including allogeneic induced pluripotent stem cell (allo-iPSC)-derived cell therapy. Beta-2-Microglobulin gene-knockout,human leukocyte antigen (HLA) class I-deficient iPSCs can evade immune rejection by host T cells,which occurs due to HLA mismatches. However,natural killer (NK) cells recognize HLA class Ⅰ-deficient cells and reject them,which is known as the missing-self response. Introducing chimeric HLA-E protein to HLA class Ⅰ-deficient iPSCs suppresses the missing-self response of NK cells expressing the inhibitory receptor NKG2A; however,technology to suppress NKG2A-negative NK cells is still required. Here,we developed novel agonists for the other inhibitory receptor,killer immunoglobulin receptor (KIR),on NK cells. We found that antibodies that bind to activating KIR enhance NK cell activation and developed selective agonists for inhibitory KIRs (KIR2DL1,KIR2DL2/3,and KIR3DL1). Introducing these selective inhibitory KIR agonists on T cells and HLA class Ⅰ-deficient iPSCs allowed them to evade immune rejection by NK cells. Additionally,we identified an NKG2A-selective agonist as an alternative to chimeric HLA-E,which stimulates the activating receptor NKG2C. This technology enhances immune tolerance in allo-iPSCs and facilitates the development of various iPSC-derived regenerative medicines. The online version contains supplementary material available at 10.1038/s41598-025-18394-z. Subject terms: Allotransplantation,NK cells View Publication

The growth factor and small molecule protocol are the two primary approaches for generating human induced pluripotent stem cell-derived hepatocyte-like cells (iPSC-HLCs). We compared the efficacy of the growth factor and small molecule protocols across fifteen different human iPSC lines. Morphological assessment,relative quantification of gene expression,protein expression and proteomic studies were carried out. HLCs derived from the growth factor protocol displayed mature hepatocyte morphological features including a raised,polygonal shape with well-defined refractile borders,granular cytoplasm with lipid droplets and/or vacuoles with multiple spherical nuclei or a large centrally located nucleus; significantly elevated hepatocyte gene and protein expression including AFP,HNF4A,ALBUMIN,and proteomic and metabolic features that are more aligned with a mature phenotype. HLCs derived from the small molecule protocol showed a dedifferentiated,proliferative phenotype that is more akin to liver tumor-derived cell lines. These experimental results suggest that HLCs derived from growth factors are better suited for studies of metabolism,biotransformation,and viral infection. View Publication

Juvenile dermatomyositis (JDM) is a pediatric autoimmune disease associated with characteristic rash and proximal muscle weakness. To gain insight into differential lymphocyte gene expression in JDM,peripheral blood mononuclear cells from 4 new-onset JDM patients and 4 healthy controls were sorted into highly enriched lymphocyte populations for RNAseq analysis. NK cells from JDM patients had substantially greater differentially expressed genes (273) than T (57) and B (33) cells. Upregulated genes were associated with the innate immune response and cell cycle,while downregulated genes were associated with decreased ribosomal RNA. Suppressed ribosomal RNA in JDM NK cells was validated by measuring transcription and phosphorylation levels. We confirmed a population of low ribosome expressing NK cells in healthy adults and children. This population of low ribosome NK cells was substantially expanded in 6 treatment-na{\{i}}ve JDM patients and was associated with decreased NK cell degranulation. The enrichment of this NK low ribosome population was completely abrogated in JDM patients with quiescent disease. Together these data suggest NK cells are highly activated in new-onset JDM patients with an increased population of low ribosome expressing NK cells which correlates with decreased NK cell function and resolved with control of active disease." View Publication

Although FOXP3+ regulatory T cells (Treg) depend on IL-2 produced by other cells for their survival and function,the levels of IL-2 in inflamed tissue are low,making it unclear how Treg access this critical resource. Here,we show that Treg use heparanase (HPSE) to access IL-2 sequestered by heparan sulfate (HS) within the extracellular matrix (ECM) of inflamed central nervous system tissue. HPSE expression distinguishes human and murine Treg from conventional T cells and is regulated by the availability of IL-2. HPSE-/- Treg have impaired stability and function in vivo,including in the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Conversely,endowing monoclonal antibody-directed chimeric antigen receptor (mAbCAR) Treg with HPSE enhances their ability to access HS-sequestered IL-2 and their ability to suppress neuroinflammation in vivo. Together,these data identify a role for HPSE and the ECM in immune tolerance,providing new avenues for improving Treg-based therapy of autoimmunity. Regulatory T cell (Treg) maintenance and function require IL-2,yet this cytokine is only present in low levels in vivo. In this study,the authors demonstrate that that Treg use heparanase to access IL-2 bound to heparan sulfate proteoglycans in the extracellular matrix of inflamed brain tissue in mice. View Publication

SUMMARYRegulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T-cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here,we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly,CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28 activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed,CAR Tregs secreted high levels of inflammatory cytokines,with a subset of FOXP3+ CAR Tregs uniquely acquiring CD40L surface expression and producing IFNγ. Interestingly,decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy. Graphical Abstract View Publication

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy characterized by desmoplastic stroma,immunosuppressive tumor microenvironment (TME),and resistance to standard therapies. Natural killer (NK) cell-based immunotherapies have shown limited efficacy due to impaired persistence,infiltration,and function in PDAC. Methods: We established a direct reprogramming strategy to generate cytotoxic NK cells (1 F-NKs) by targeting BCL11B,a transcription factor essential for T cell lineage commitment,using shRNA or CRISPR/Cas9 in peripheral blood mononuclear cells (PBMCs). A genome-wide CRISPR/Cas9 screen identified tumor-intrinsic modulators of NK resistance. Functional and in vivo studies assesses the efficacy of 1 F-NKs alone and in combination with mesothelin (MSLN)-CAR engineering and PKMYT1 inhibition. Results: BCL11B depletion enabled the generation of CD56brightCD16bright 1 F-NKs with potent cytotoxicity and elevated NKG2D and CX3CR1 expression. Site-specific integration of a mesothelin (MSLN)-CAR into BCL11B locus generated MSLN-1 F-NKs with stable antigen specific activity. A genome-wide screen identified PKMYT1 as a modulator of tumor resistance to NK cell-mediated killing; its inhibition by RP6306 upregulated NKG2D ligands (MICA/B) and CX3CL1,sensitizing PDACs to 1 F-NK cytotoxicity. In PDAC xenograft models,1 F-NKs alone or combined with CAR engineering and RP6306 significantly reduced tumor growth and prolonged survival. Notably,this triple combination elicited a synergistic antitumor effect,outperforming each monotherapy or dual combination. Conclusions: This study presents a synergistic immunotherapy platform that integrates NK reprogramming,CAR engineering,and tumor sensitization. The combinatorial approach significantly enhances antitumor efficacy in PDAC and offers a promising strategy for overcoming immune resistance in solid tumors. View Publication

Cellular senescence and the senescence-associated secretory phenotype (SASP) are implicated in aging and age-related disease,and SASP-related inflammation is thought to contribute to tissue dysfunction in aging and diseased animals. However,whether and how SASP factors influence the regenerative capacity of tissues remains unclear. Here,using intestinal organoids as a model of tissue regeneration,we show that SASP factors released by senescent fibroblasts deregulate stem cell activity and differentiation and ultimately impair crypt formation. We identify the secreted N-terminal domain of Ptk7 as a key component of the SASP that activates non-canonical Wnt / Ca2+ signaling through FZD7 in intestinal stem cells (ISCs). Changes in cytosolic [Ca2+] elicited by Ptk7 promote nuclear translocation of YAP and induce expression of YAP/TEAD target genes,impairing symmetry breaking and stem cell differentiation. Our study discovers secreted Ptk7 as a factor released by senescent cells and provides insight into the mechanism by which cellular senescence contributes to tissue dysfunction in aging and disease. View Publication

Innate lymphoid cells (ILCs) are a new family of immune cells that play important roles in innate immunity in mucosal tissues,and in the maintenance of tissue and metabolic homeostasis. Recently,group 2 ILCs (ILC2s) were found to promote the development and effector functions of Th2-type CD4(+) T cells by interacting directly with T cells or by activating dendritic cells,suggesting a role for ILC2s in regulating adaptive immunity. However,our current knowledge on the role of ILCs in humoral immunity is limited. In this study,we found that ILC2s isolated from the lungs of naive BALB/c mice enhanced the proliferation of B1- as well as B2-type B cells and promoted the production of IgM,IgG1,IgA,and IgE by these cells in vitro. Soluble factors secreted by ILC2s were sufficient to enhance B cell Ig production. By using blocking Abs and ILC2s isolated from IL-5-deficient mice,we found that ILC2-derived IL-5 is critically involved in the enhanced production of IgM. Furthermore,when adoptively transferred to Il7r(-/-) mice,which lack ILC2s and mature T cells,lung ILC2s promoted the production of IgM Abs to a polysaccharide Ag,4-hydroxy-3-nitrophenylacetyl Ficoll,within 7 d of airway exposure in vivo. These findings add to the growing body of literature regarding the regulatory functions of ILCs in adaptive immunity,and suggest that lung ILC2s promote B cell production of early Abs to a respiratory Ag even in the absence of T cells. View Publication