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  • Roasted Coffees High in Lipophilic Antioxidants and Chlorogenic Acid Lactones Are More Neuroprotective than Green Coffees. 19772322

    Oxidative stress is involved in many neurodegenerative processes leading to age-related cognitive decline. Coffee, a widely consumed beverage, is rich in many bioactive components, including polyphenols with antioxidant potential. In this study, regular and decaffeinated samples of both roasted and green coffee all showed high hydrophilic antioxidant activity in vitro, whereas lipophilic antioxidant activities were on average 30-fold higher in roasted than in green coffee samples. In primary neuronal cell culture, pretreatment with green and roasted coffees (regular and decaffeinated) protected against subsequent H(2)O(2)-induced oxidative stress and improved neuronal cell survival (green coffees increased neuron survival by 78%, compared to 203% by roasted coffees). All coffee extracts inhibited ERK1/2 activation, indicating a potential attenuating effect in stress-induced neuronal cell death. Interestingly, only roasted coffee extracts inhibited JNK activation, evidencing a distinctive neuroprotective benefit. Analysis of coffee phenolic compounds revealed that roasted coffees contained high levels of chlorogenic acid lactones (CGLs); a significant correlation between CGLs and neuroprotective efficacy was observed (R(2) = 0.98). In conclusion, this study showed that roasted coffees are high in lipophilic antioxidants and CGLs, can protect neuronal cells against oxidative stress, and may do so by modulation of the ERK1/2 and JNK signaling pathways.
    Document Type:
    Reference
    Product Catalog Number:
    AP132F
    Product Catalog Name:
    Goat Anti-Rabbit IgG Antibody, FITC conjugate

  • Poly(vinyl alcohol)/gelatin Hydrogels Cultured with HepG2 Cells as a 3D Model of Hepatocellular Carcinoma: A Morphological Study. 25590431

    It has been demonstrated that three-dimensional (3D) cell culture models represent fundamental tools for the comprehension of cellular phenomena both for normal and cancerous tissues. Indeed, the microenvironment affects the cellular behavior as well as the response to drugs. In this study, we performed a morphological analysis on a hepatocarcinoma cell line, HepG2, grown for 24 days inside a bioartificial hydrogel composed of poly(vinyl alcohol) (PVA) and gelatin (G) to model a hepatocellular carcinoma (HCC) in 3D. Morphological features of PVA/G hydrogels were investigated, resulting to mimic the trabecular structure of liver parenchyma. A histologic analysis comparing the 3D models with HepG2 cell monolayers and tumor specimens was performed. In the 3D setting, HepG2 cells were viable and formed large cellular aggregates showing different morphotypes with zonal distribution. Furthermore, β-actin and α5β1 integrin revealed a morphotype-related expression; in particular, the frontline cells were characterized by a strong immunopositivity on a side border of their membrane, thus suggesting the formation of lamellipodia-like structures apt for migration. Based on these results, we propose PVA/G hydrogels as valuable substrates to develop a long term 3D HCC model that can be used to investigate important aspects of tumor biology related to migration phenomena.
    Document Type:
    Reference
    Product Catalog Number:
    AB1928
    Product Catalog Name:
    Anti-Integrin α5 Antibody, CT, Intracellular

  • Synthetic lethal interactions between EGFR and PARP inhibition in human triple negative breast cancer cells. 23071597

    Few therapeutic options exist for the highly aggressive triple negative breast cancers (TNBCs). In this study, we report that a contextual synthetic lethality can be achieved both in vitro and in vivo with combined EGFR and PARP inhibition with lapatinib and ABT-888, respectively. The mechanism involves a transient DNA double strand break repair deficit induced by lapatinib and subsequent activation of the intrinsic pathway of apoptosis. Further dissection of the mechanism reveals that EGFR and BRCA1 can be found in the same protein complex, which is reduced by lapatinib. Interestingly, lapatinib also increases cytosolic BRCA1 and EGFR, away from their nuclear DNA repair substrates. Taken together, these results reveal a novel regulation of homologous recombination repair involving EGFR and BRCA1 interaction and alteration of subcellular localization. Additionally, a contextual synthetic lethality may exist between combined EGFR and PARP inhibitors.
    Document Type:
    Reference
    Product Catalog Number:
    07-164
    Product Catalog Name:
    Anti-phospho-H2A.X (Ser139) Antibody

  • Recognition and degradation of myelin basic protein peptides by serum autoantibodies: novel biomarker for multiple sclerosis. 18178866

    The pathologic role of autoantibodies in autoimmune disease is widely accepted. Recently, we reported that anti-myelin basic protein (MBP) serum Abs from multiple sclerosis (MS) patients exhibit proteolytic activity toward the autoantigen. The aim of this study is to determine MBP epitopes specific for the autoantibodies in MS and compare these data with those from other neuronal disorders (OND), leading to the generation of new diagnostic and prognostic criteria. We constructed a MBP-derived recombinant epitope library covering the entire molecule. We used ELISA and PAGE/surface-enhanced laser desorption/ionization mass spectroscopy assays to define the epitope binding/cleaving activities of autoantibodies isolated from the sera of 26 MS patients, 22 OND patients, and 11 healthy individuals. The levels of autoantibodies to MBP fragments 48-70 and 85-170 as well as to whole MBP and myelin oligodendrocyte glycoprotein molecules were significantly higher in the sera of MS patients than in those of healthy donors. In contrast, selective reactivity to the two MBP fragments 43-68 and 146-170 distinguished the OND and MS patients. Patients with MS (77% of progressive and 85% of relapsing-remitting) but only 9% of patients with OND and no healthy donors were positive for catalysis, showing pronounced epitope specificity to the encephalitogenic MBP peptide 81-103. This peptide retained its substrate properties when flanked with two fluorescent proteins, providing a novel fluorescent resonance energy transfer approach for MS studies. Thus, anti-MBP autoantibody-mediated, epitope-specific binding and cleavage may be regarded as a specific characteristic of MS compared with OND and healthy donors and may serve as an additional biomarker of disease progression.
    Document Type:
    Reference
    Product Catalog Number:
    MAB381
    Product Catalog Name:
    Anti-Myelin Basic Protein Antibody, a.a. 119-131, clone 2

  • CD14-dependent activation of protein kinase C and mitogen-activated protein kinases (p42 and p44) in human monocytes treated with bacterial lipopolysaccharide. 7521366

    To investigate mechanisms of mononuclear phagocyte cell signaling, the effects of bacterial LPS on protein kinase activities in normal human peripheral blood monocytes were examined. Incubation of intact monocytes with LPS brought about time- and concentration-dependent increases in myelin basic protein (MBP) phosphotransferase activity in high speed supernatants of cell lysates. Anion-exchange chromatography on Mono Q demonstrated that LPS treatment resulted in two principal peaks of stimulated MBP kinase activity. Evidence was obtained to indicate that the first eluted peak of MBP kinase activity is accounted for by p42 and p44 mitogen-activated protein (MAP) kinases. Thus, 1) MBP kinase activity within peak 1 was quantitatively precipitated by anti-MAP kinase Abs, 2) the enzyme effectively phosphorylated a specific peptide substrate, 3) peak 1 contained proteins of subunit size M(r) 42,000 and M(r) 44,000 that reacted specifically with anti-MAP kinase Abs, and that 4) were recognized by anti-phosphotyrosine Abs only after stimulation of cells with LPS. Studies of the second peak of LPS-stimulated MBP kinase activity indicate that it is an isoform of protein kinase C (PKC) because: 1) enzyme activity was quantitatively immunoprecipitated by anti-PKC Abs, 2) the activity of the enzyme was potently and selectively inhibited by a specific peptide modeled on the autoinhibitory domain of PKC, and 3) the presence of a protein of subunit size M(r) 80,000 recognized by anti-PKC Abs. Because the second peak of MBP kinase activity (like the first) was active in the absence of added calcium and in the presence of 2 mM EGTA, it appears to be a type II, calcium-independent isoform of PKC. Abs to CD14 completely abrogated LPS-induced activation of both Mono Q peaks of MBP phosphotransferase activity. These results indicate that LPS coordinately activates both an apparently calcium-independent PKC and MAP kinase in mononuclear phagocytes and these responses appear to be initiated by signaling through the cell surface receptor, CD14.
    Document Type:
    Reference
    Product Catalog Number:
    06-182
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