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BACKGROUND The nonsense mutation,c.3846G{\textgreater}A (aka: W1282X-CFTR) leads to a truncated transcript that is susceptible to nonsense-mediated decay (NMD) and produces a shorter protein that is unstable and lacks normal channel activity in patient-derived tissues. However,if overexpressed in a heterologous expression system,the truncated mutant protein has been shown to mediate CFTR channel function following the addition of potentiators. In this study,we asked if a quadruple combination of small molecules that together inhibit nonsense mediated decay,stabilize both halves of the mutant protein and potentiate CFTR channel activity could rescue the functional expression of W1282X-CFTR in patient derived nasal cultures. METHODS We identified the CFTR domains stabilized by corrector compounds supplied from AbbVie using a fragment based,biochemical approach. Rescue of the channel function of W1282X.-CFTR protein by NMD inhibition and small molecule protein modulators was studied using a bronchial cell line engineered to express W1282X and in primary nasal epithelial cultures derived from four patients homozygous for this mutation. RESULTS We confirmed previous studies showing that inhibition of NMD using the inhibitor: SMG1i,led to an increased abundance of the shorter transcript in a bronchial cell line. Interestingly,on top of SMG1i,treatment with a combination of two new correctors developed by Galapagos/AbbVie (AC1 and AC2-2,separately targeting either the first or second half of CFTR and promoting assembly,significantly increased the potentiated channel activity by the mutant in the bronchial epithelial cell line and in patient-derived nasal epithelial cultures. The average rescue effect in primary cultures was approximately 50{\%} of the regulated chloride conductance measured in non-CF cultures. CONCLUSIONS These studies provide the first in-vitro evidence in patient derived airway cultures that the functional defects incurred by W1282X,has the potential to be effectively repaired pharmacologically. View Publication

Antiviral strategies to inhibit Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and the pathogenic consequences of COVID-19 are urgently required. Here,we demonstrate that the NRF2 antioxidant gene expression pathway is suppressed in biopsies obtained from COVID-19 patients. Further,we uncover that NRF2 agonists 4-octyl-itaconate (4-OI) and the clinically approved dimethyl fumarate (DMF) induce a cellular antiviral program that potently inhibits replication of SARS-CoV2 across cell lines. The inhibitory effect of 4-OI and DMF extends to the replication of several other pathogenic viruses including Herpes Simplex Virus-1 and-2,Vaccinia virus,and Zika virus through a type I interferon (IFN)-independent mechanism. In addition,4-OI and DMF limit host inflammatory responses to SARS-CoV2 infection associated with airway COVID-19 pathology. In conclusion,NRF2 agonists 4-OI and DMF induce a distinct IFN-independent antiviral program that is broadly effective in limiting virus replication and in suppressing the pro-inflammatory responses of human pathogenic viruses,including SARS-CoV2. View Publication

Tumor patients often exhibit limited responses to immunotherapy owing to the low immunogenicity and immunosuppressive environment of tumors. Our previous studies revealed that cryo-thermal therapy caused tumor cell rupture due to mechanical compression,notably causing the release of a substantial amount of DAMPs (danger-associated molecular patterns),such as heat shock protein 70,calreticulin and high-mobility group box protein 1; the release of these DAMPs increased myeloid cell maturation,thereby reshaping the systemic immune environment and ultimately inducing durable CD4+ T helper type 1 (Th1) cell-dominated antitumor immunity. In fact,under conditions of mechanical stress and rapid temperature changes,the disruption of tumor cells caused by cryo-thermal therapy results in extensive deoxyribonucleic acid (DNA) damage and the rapid release of substantial amounts of DNA. Consequently,tumor-derived DNA,which potently activates innate immunity by engaging multiple DNA sensors,plays a pivotal role in orchestrating antitumor immunity. We hypothesized that cryo-thermal therapy induces the transient release of high levels of DNA,which modulates CD11b+ myeloid cell function,subsequently influencing CD4+ Th1-cell dominated antitumor immune responses. In this study,a B16F10 melanoma model was established,and DNA concentrations were measured at different time points after cryo-thermal therapy. Deoxyribonuclease I (DNase I) was subsequently administered immediately following cryo-thermal therapy to deplete extracellular DNA,allowing an investigation of the role of DNA in regulating CD11b+ myeloid cell function and CD4+ T cell differentiation. The phenotype and function of CD11b+ myeloid cells and CD4+ T cells were assessed by flow cytometry,RNA sequencing,and cell culture in vitro. Our studies confirmed that cryo-thermal therapy triggered a transient release of high levels of DNA,which was internalized by CD11b+ myeloid cells via C-type lectin receptors and subsequently sensed by inflammasomes. Then,the intracellular sensing of DNA induced the production of the mature form of interleukin (IL)-18,ultimately promoting the Th1 differentiation of CD4+ T cells. This study highlights the pivotal role of DNA release after cryo-thermal therapy in driving CD4+ Th1 cell-dominant antitumor immunity. View Publication

Splice-site mutations in the beta-globin gene can lead to aberrant transcripts and decreased functional beta-globin,causing beta-thalassemia. Triplex-forming DNA oligonucleotides (TFOs) and peptide nucleic acids (PNAs) have been shown to stimulate recombination in reporter gene loci in mammalian cells via site-specific binding and creation of altered helical structures that provoke DNA repair. We have designed a series of triplex-forming PNAs that can specifically bind to sequences in the human beta-globin gene. We demonstrate here that these PNAs,when cotransfected with recombinatory donor DNA fragments,can promote single base-pair modification at the start of the second intron of the beta-globin gene,the site of a common thalassemia-associated mutation. This single base pair change was detected by the restoration of proper splicing of transcripts produced from a green fluorescent protein-beta-globin fusion gene. The ability of these PNAs to induce recombination was dependent on dose,sequence,cell-cycle stage,and the presence of a homologous donor DNA molecule. Enhanced recombination,with frequencies up to 0.4%,was observed with use of the lysomotropic agent chloroquine. Finally,we demonstrate that these PNAs were effective in stimulating the modification of the endogenous beta-globin locus in human cells,including primary hematopoietic progenitor cells. This work suggests that PNAs can be effective tools to induce heritable,site-specific modification of disease-related genes in human cells. View Publication

The pervasive influence of secreted Wnt signaling proteins in tissue homeostasis and tumorigenesis has galvanized efforts to identify small molecules that target Wnt-mediated cellular responses. By screening a diverse synthetic chemical library,we have discovered two new classes of small molecules that disrupt Wnt pathway responses; whereas one class inhibits the activity of Porcupine,a membrane-bound acyltransferase that is essential to the production of Wnt proteins,the other abrogates destruction of Axin proteins,which are suppressors of Wnt/beta-catenin pathway activity. With these small molecules,we establish a chemical genetic approach for studying Wnt pathway responses and stem cell function in adult tissue. We achieve transient,reversible suppression of Wnt/beta-catenin pathway response in vivo,and we establish a mechanism-based approach to target cancerous cell growth. The signal transduction mechanisms shown here to be chemically tractable additionally contribute to Wnt-independent signal transduction pathways and thus could be broadly exploited for chemical genetics and therapeutic goals. View Publication

BACKGROUND: Inflammatory processes play important roles in both neuropathic and inflammatory pain states,but the effects of inflammation per se within the sensory ganglia are not well understood. The cytokine growth-related oncogene (GRO/KC; CXCL1) shows strong,rapid upregulation in dorsal root ganglion (DRG) in both nerve injury and inflammatory pain models. We examined the direct effects of GRO/KC on small diameter DRG neurons,which are predominantly nociceptive. Whole cell voltage clamp technique was used to measure voltage-activated potassium (K) currents in acutely cultured adult rat small diameter sensory neurons. Fluorescently labeled isolectin B4 (IB4) was used to classify cells as IB4-positive or IB4-negative. RESULTS: In IB4-negative neurons,voltage-activated K current densities of both transient and sustained components were increased after overnight incubation with GRO/KC (1.5 nM),without marked changes in voltage dependence or kinetics. The average values for the slow and fast decay time constants at 20 mV were unchanged by GRO/KC. The amplitude of the fast inactivating component increased significantly with no large shifts in the voltage dependence of inactivation. The increase in K currents was completely blocked by co-incubation with protein synthesis inhibitor cycloheximide (CHX) or NF-kappaB inhibitors pyrrolidine dithiocarbamate (PDTC) or quinazoline (6-Amino-4-(4-phenoxypheny lethylamino;QNZ). In contrast,the voltage-activated K current of IB4-positive neurons was unchanged by GRO/KC. GRO/KC incubation caused no significant changes in the expression level of eight selected voltage-gated K channel genes in quantitative PCR analysis. CONCLUSION: The results suggest that GRO/KC has important effects in inflammatory processes via its direct actions on sensory neurons,and that activation of NF-kappaB is involved in the GRO/KC-induced enhancement of K currents. View Publication

Recent evidence suggests that pancreatic cancer and other solid tumors contain a subset of tumorigenic cells capable of extensive self-renewal that contribute to metastasis and treatment resistance. Sorafenib (SO) is a promising new multikinase inhibitor for treatment of advanced kidney and liver cancers. We report here targeting of pancreatic cancer stem cells (CSC) by SO and the development of a strategy to enhance this effect. Although SO administration diminished clonogenicity,spheroid formation,aldehyde dehydrogenase 1 (ALDH1) activity,growth on immunodeficient mice,proliferation,and angiogenesis and induced apoptosis,we observed SO-induced activation of NF-kappaB associated with survival and regrowth of spheroids. For enhanced elimination of CSC characteristics by SO,we cotreated cells with sulforaphane (SF). This broccoli isothiocyanate was recently described to eliminate pancreatic CSCs by downregulation of NF-kappaB activity without inducing toxic side effects. On combination treatment,SF completely eradicated SO-induced NF-kappaB binding,which was associated with abrogated clonogenicity,spheroid formation,ALDH1 activity,migratory capacity,and induction of apoptosis. In vivo,combination therapy reduced the tumor size in a synergistic manner. This was due to induction of apoptosis,inhibition of proliferation and angiogenesis,and downregulation of SO-induced expression of proteins involved in epithelial-mesenchymal transition. Our data suggest that SF may be suited to increase targeting of CSCs by SO. View Publication

Transfusion-related acute lung injury (TRALI) is a serious complication of transfusion and has been ranked as one of the leading causes of transfusion-related fatalities. Nonetheless,many details of the immunopathogenesis of TRALI,particularly with respect to recipient factors are unknown. We used a murine model of antibody-mediated TRALI in an attempt to understand the role that recipient lymphocytes might play in TRALI reactions. Intravenous injection of an IgG2a antimurine major histocompatibility complex class I antibody (34-1-2s) into BALB/c mice induced moderate hypothermia and pulmonary granulocyte accumulation but no pulmonary edema nor mortality. In contrast,34-1-2s injections into mice with severe combined immunodeficiency caused severe hypothermia,severe pulmonary edema,and approximately 40% mortality indicating a critical role for T and B lymphocytes in suppressing TRALI reactions. Adoptive transfer of purified CD8(+) T lymphocytes or CD4(+) T cells but not CD19(+) B cells into the severe combined immunodeficiency mice alleviated the antibody-induced hypothermia,lung damage,and mortality,suggesting that T lymphocytes were responsible for the protective effect. Taken together,these results suggest that recipient T lymphocytes play a significant role in suppressing antibody-mediated TRALI reactions. They identify a potentially new recipient mechanism that controls the severity of TRALI reactions. View Publication

The bisdichloroacetyldiamine WIN 18,446 reversibly inhibits spermatogenesis in many species,including humans; however,the mechanism by which WIN 18,446 functions is unknown. As retinoic acid is essential for spermatogenesis,we hypothesized that WIN 18,446 might inhibit retinoic acid biosynthesis from retinol (vitamin A) within the testes by inhibiting the enzyme aldehyde dehydrogenase 1a2 (ALDH1a2). We studied the effect of WIN 18,446 on ALDH1a2 enzyme activity in vitro,and on spermatogenesis and fertility in vivo,in mature male rabbits for 16 weeks. WIN 18,446 markedly inhibited ALDH1a2 enzyme activity in vitro with an IC(50) of 0.3 μM. In vivo,the oral administration of 200 mg/kg WIN 18,446 to male rabbits for 16 weeks significantly reduced intratesticular concentrations of retinoic acid,severely impaired spermatogenesis,and caused infertility. Reduced concentrations of intratesticular retinoic acid were apparent after only 4 weeks of treatment and preceded the decrease in sperm counts and the loss of mature germ cells in tissue samples. Sperm counts and fertility recovered after treatment was discontinued. These findings demonstrate that bisdichloroacetyldiamines such as WIN 18,446 reversibly suppress spermatogenesis via inhibition of testicular retinoic acid biosynthesis by ALDH1a2. These findings suggest that ALDH1a2 is a promising target for the development of a reversible,nonhormonal male contraceptive. View Publication