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

Peroxynitrite toxicity is a major cause of neuronal injury in stroke and neurodegenerative disorders. The mechanisms underlying the neurotoxicity induced by peroxynitrite are still unclear. In this study,we observed that TPEN [N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine],a zinc chelator,protected against neurotoxicity induced by exogenous as well as endogenous (coadministration of NMDA and a nitric oxide donor,diethylenetriamine NONOate) peroxynitrite. Two different approaches to detecting intracellular zinc release demonstrated the liberation of zinc from intracellular stores by peroxynitrite. In addition,we found that peroxynitrite toxicity was blocked by inhibitors of 12-lipoxygenase (12-LOX),p38 mitogen-activated protein kinase (MAPK),and caspase-3 and was associated with mitochondrial membrane depolarization. Inhibition of 12-LOX blocked the activation of p38 MAPK and caspase-3. Zinc itself induced the activation of 12-LOX,generation of reactive oxygen species (ROS),and activation of p38 MAPK and caspase-3. These data suggest a cell death pathway triggered by peroxynitrite in which intracellular zinc release leads to activation of 12-LOX,ROS accumulation,p38 activation,and caspase-3 activation. Therefore,therapies aimed at maintaining intracellular zinc homeostasis or blocking activation of 12-LOX may provide a novel avenue for the treatment of inflammation,stroke,and neurodegenerative diseases in which the formation of peroxynitrite is thought to be one of the important causes of cell death. View Publication

Triple-negative breast cancer (TNBC) is an aggressive and clinically challenging subtype defined by the absence of estrogen receptor,progesterone receptor,and HER2 amplification,resulting in poor prognosis and limited therapeutic options. Targeting alternative molecular pathways is urgently needed to overcome resistance and improve patient outcomes. CD147 has emerged as surface marker associated with tumor progression and immune evasion. In this study,CD147 and MHC class I—a key inhibitory ligand for natural killer cells—were analyzed in breast cancer cell lines (MCF7,MDA-MB-453,MDA-MB-231,and HCC38) using flow cytometry. The therapeutic efficacy of a humanized anti-CD147 monoclonal antibody (HuM6-1B9) was evaluated for its capacity to potentiate antibody-dependent cellular cytotoxicity (ADCC). HuM6-1B9 demonstrated the strong binding to MDA-MB-231 (KD = 4.982 nM) and HCC38 (KD = 4.523 nM),which are representative TNBC cell lines. In 3D spheroid models,HuM6-1B9 significantly enhanced PBMC-mediated ADCC,leading to a marked reduction in TNBC spheroid viability. Co-culture of CFSE-labeled MDA-MB-231 and HCC38 cells with primary NK cells confirmed robust ADCC,achieving 50% and 70% cytotoxicity,respectively,despite high MHC class I expression. Live-cell imaging demonstrated caspase-3/7 activation consistent with apoptosis in NK-targeted tumor cells,while CD107a degranulation and IFN-γ secretion confirmed the functional contribution of HuM6-1B9 to ADCC enhancement. Importantly,HuM6-1B9 did not promote migration or invasion in MDA-MB-231 cells,supporting its safety profile regarding metastasis. Collectively,these findings establish HuM6-1B9 as a promising immunotherapeutic candidate that overcomes immune resistance and selectively eliminates TNBC cells through ADCC without enhancing metastatic potential. By integrating mechanistic assays of NK cytotoxicity,apoptosis,and 3D tumor spheroids,this study provides clinically relevant insights underscoring the translational potential of HuM6-1B9 in TNBC immunotherapy. View Publication

Pluripotent cancer stem cells play a pivotal role in inducing phenotypic plasticity across various cancer types,including bladder cancer. This plasticity,crucial for cancer progression,is largely regulated by epigenetic modifications including N6-methyladenosine (m6A) in RNAs. However,the role of the m6A reader protein YTHDC2 in this process remains poorly understood. In this study,we uncovered that the depletion of YTHDC2 significantly increased the pool of bladder cancer stem cells (BCSCs),resulting in a phenotypic shift towards a more invasive subtype of bladder cancer. This shift was characterized by enhanced proliferation,migration,invasion,and self-renewal capabilities of cancer cells,highlighting YTHDC2’s function as a tumor suppressor. Mechanistically,YTHDC2 recognized and bound to m6A-modified SOX2 mRNA,resulting in translational inhibition of SOX2. In conclusion,our study identifies YTHDC2 as a tumor suppressor in bladder cancer through inhibiting SOX2-mediated cell pluripotency and underscores the therapeutic potential of targeting the YTHDC2-SOX2 axis in bladder cancer. View Publication

Multiple myeloma (MM) is a plasma cell malignancy that disrupts bone homeostasis by suppressing osteogenesis and promoting osteoclast activity. While most therapeutic interventions to date have focused on targeting tumor cells and reducing osteolysis,we investigate whether osteoinductive strategies can restore bone formation and counteract disease progression. Using a human bone marrow-like scaffold model that enables direct in vivo evaluation of tumor–stroma interactions and human bone formation,we demonstrate that MM-derived mesenchymal stromal cells (MSCs) retain osteogenic potential but are functionally suppressed by MM cells. Transcriptomic profiling of MM-primed MSCs revealed the downregulation of small leucine-rich proteoglycans (SLRPs),ASPN,OGN,and OMD,key mediators of bone morphogenetic protein (BMP) signaling,which governs osteoblast differentiation. Among the BMPs analyzed,BMP6 emerged as a potent inducer of osteogenesis and regulator of the expression of these SLRPs. Notably,BMP6 selectively promoted bone formation without enhancing osteoclastogenesis and attenuated inflammatory and tumor-supportive MSC phenotypes. BMP6 also directly inhibited MM cell proliferation and suppressed IL6-induced growth. These findings highlight BMP6 as a distinct multifunctional regulator warranting further investigation as a potential therapeutic approach,while establishing the humanized model as a valuable platform for dissecting tumor–bone interactions in MM. View Publication

TAR DNA-binding protein 43 (TDP-43) dysfunction is a hallmark of several neurodegenerative diseases,including frontotemporal dementia,amyotrophic lateral sclerosis,and Alzheimer’s disease. Although cryptic exon inclusion is a well-characterized consequence of TDP-43 loss of function,emerging evidence reveals broader roles in RNA metabolism,notably in the regulation of alternative polyadenylation (APA) of disease-relevant transcripts. In the present study,we examined 3′ untranslated region lengthening events in the brains of individuals with frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP),focusing on the functional impact of APA dysregulation. To investigate whether TDP-43-mediated APA events occur in the postmortem brain,we measured the 3′ untranslated region length of the retromer component vacuolar protein sorting 35 (VPS35) and the ETS transcription factor (ELK1) in the frontal cortex of a large cohort of FTLD-TDP patients and of healthy controls,and evaluated if these APA events are associated with FTLD-TDP clinical characteristic,markers of TDP-43 pathology [e.g.,hyperphosphorylated TDP-43 and cryptic stathmin-2 RNA],or the expression of VPS35 and VPS29 proteins,the latter being essential to the retromer complex. We identified robust 3′ untranslated region lengthening of VPS35 and ELK1 in FTLD-TDP,which strongly associated with markers of TDP-43 pathology,and ELK1 APA also associated with an earlier age of disease onset. Functionally,VPS35 APA was associated with reduced VPS35 and VPS29 protein expression,and lower VPS35 levels were associated with increased hyperphosphorylated TDP-43 and cryptic stathmin-2 RNA. Together,these data implicate APA dysregulation as a critical downstream consequence of TDP-43 dysfunction and suggest that TDP-43 loss may contribute to retromer impairment through APA-mediated repression of retromer subunits. Recent work has shown that TDP-43 loss in frontotemporal dementia (FTD) induces changes in alternative polyadenylation,but the functional consequences of this are unclear. This study reports that 3′UTR lengthening of VPS35 in FTD patient brain samples correlates with reduced VPS35 and VPS29 protein levels,suggesting that TDP-43 loss induces retromer dysfunction. View Publication

Viral infection triggers induction of antiviral cytokines and effectors,which are critical mediators of innate antiviral immune response. It has been shown that the processing body-associated protein LSm14A is involved in the induction of antiviral cytokines in cell lines but in vivo evidence is lacking. By generating LSm14A-deficient mice,in this study,we show that LSm14A plays a critical and specific role in the induction of antiviral cytokines in dendritic cells (DCs) but not in macrophages and fibroblasts. Induction of antiviral cytokines triggered by the DNA viruses HSV-1 and murid herpesvirus 68 and the RNA virus vesicular stomatitis virus but not Sendai virus was impaired in Lsm14a(-/-) DCs,which is correlated to the functions of the adaptor protein MITA/STING in the antiviral signaling pathways. LSm14A deficiency specifically downregulated MITA/STING level in DCs by impairing its nuclear mRNA precursor processing and subsequently impaired antiviral innate and adaptive immune responses. Our findings reveal a nuclear mRNA precursor processing and cell-specific regulatory mechanism of antiviral immune responses. View Publication

B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1(+) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines,application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain -3 (TIM-3) on B cells,a novel molecule that has recently been described to induce anergy in T cells. Interestingly,elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall,these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease. View Publication

Spatial organization of the genome plays a central role in gene expression,DNA replication,and repair. But current epigenomic approaches largely map DNA regulatory elements outside of the native context of the nucleus. Here we report assay of transposase-accessible chromatin with visualization (ATAC-see),a transposase-mediated imaging technology that employs direct imaging of the accessible genome in situ,cell sorting,and deep sequencing to reveal the identity of the imaged elements. ATAC-see revealed the cell-type-specific spatial organization of the accessible genome and the coordinated process of neutrophil chromatin extrusion,termed NETosis. Integration of ATAC-see with flow cytometry enables automated quantitation and prospective cell isolation as a function of chromatin accessibility,and it reveals a cell-cycle dependence of chromatin accessibility that is especially dynamic in G1 phase. The integration of imaging and epigenomics provides a general and scalable approach for deciphering the spatiotemporal architecture of gene control. View Publication

Tissue-specific control of gene expression is an invaluable tool for studying various biological processes and medical applications. Efficient regulatory systems have been utilized to control transgene expression in various types of DNA viral or integrating viral vectors. However,existing regulatory systems are difficult to transfer into negative-strand RNA virus vector platforms because of significant differences in their transcriptional machineries. In this study,we developed a novel strategy for regulating transgene expression mediated by a cytoplasmic RNA vector based on a replication-defective and persistent Sendai virus (SeVdp). Because of the capacity of Sendai virus (SeV) nonstructural C proteins to specifically inhibit viral RNA synthesis,overexpression of C protein significantly reduced transgene expression mediated by SeVdp vectors. We found that SeV C overexpression concomitantly reduced SeVdp mRNA levels and genomic RNA synthesis. To control C expression,target sequences for an endogenous microRNA were incorporated into the 3' untranslated region of the C genes. Incorporation of target sequences for miR-21 into the SeVdp vector restored transgene expression in HeLa cells by decreasing C expression. Furthermore,the SeVdp vector containing target sequences for let-7a enabled cell-specific control of transgene expression in human fibroblasts and induced pluripotent stem cells. Our findings demonstrate that SeV C can be used as an effective regulator for controlling transgene expression. This strategy will contribute to efficient and less toxic SeVdp-mediated gene transfer in various biological applications. View Publication

Fragile X syndrome (FXS) is a common cause of intellectual disability that is most often due to a CGG-repeat expansion mutation in the FMR1 gene that triggers epigenetic gene silencing. Epigenetic modifying drugs can only transiently and modestly induce FMR1 reactivation in the presence of the elongated CGG repeat. As a proof-of-principle,we excised the expanded CGG-repeat in both somatic cell hybrids containing the human fragile X chromosome and human FXS iPS cells using the CRISPR/Cas9 genome editing. We observed transcriptional reactivation in approximately 67% of the CRISPR cut hybrid colonies and in 20% of isolated human FXS iPSC colonies. The reactivated cells produced FMRP and exhibited a decline in DNA methylation at the FMR1 locus. These data demonstrate the excision of the expanded CGG-repeat from the fragile X chromosome can result in FMR1 reactivation. View Publication

BACKGROUND Several compounds have been reported to induce translational readthrough of premature stop codons resulting in the production of full-length protein by interfering with ribosomal proofreading. Here we examined the effect of 2 of these compounds,gentamicin and PTC124,in human-induced pluripotent stem cell (hiPSC)-derived cardiomyocytes bearing nonsense mutations in the sodium channel gene SCN5A,which are associated with conduction disease and potential lethal arrhythmias. METHODS AND RESULTS We generated hiPSC from 2 patients carrying the mutations R1638X and W156X. hiPSC-derived cardiomyocytes from both patients recapitulated the expected electrophysiological phenotype,as evidenced by reduced Na(+) currents and action potential upstroke velocities compared with hiPSC-derived cardiomyocytes from 2 unrelated control individuals. While we were able to confirm the readthrough efficacy of the 2 drugs in Human Embryonic Kidney 293 cells,we did not observe rescue of the electrophysiological phenotype in hiPSC-derived cardiomyocytes from the patients. CONCLUSIONS We conclude that these drugs are unlikely to present an effective treatment for patients carrying the loss-of-function SCN5A gene mutations examined in this study. View Publication