Anti-ATP5B monoclonal antibody, clone FQS22002

Using flow cytometry analysis, followed by iTRAQ technology, ASC speck((+)) cells were discovered to be enriched with mitochondrial OxPhos proteins, which modulate mtROS production and downstream inflammasome activation. Two proteins, NDUFB8 (complex I) and ATP5B (complex V) are found associated with local recurrence-free survival in NPC patients. Multivariate analysis additionally indicated that NDUFB8 and ATP5B may serve as markers for local recurrence. This study experimentally links mitochondrial OxPhos proteins, inflammasome activation and clinical outcomes among NPC patients. We previously reported that tumor inflammasomes play a key role in tumor control and act as favorable prognostic markers in nasopharyngeal carcinoma (NPC). Activated inflammasomes frequently form distinguishable specks and govern the cellular secretion of IL-1?. However, we know little about the biological and biochemical differences between cells with and without apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) speck formation. In this study, we used proteomic iTRAQ analysis to analyze the proteomes of NPC cells that differ in their ASC speck formation upon cisplatin treatment. We identified proteins that were differentially over-expressed in cells with specks, and found that they fell into two Gene ontology (GO) pathways: mitochondrial oxidative phosphorylation (OxPhos) and ubiquinone metabolism. We observed up-regulation of various components of the OxPhos machinery (including NDUFB3, NDUFB8 and ATP5B), and subsequently found that these changes lead to mitochondrial ROS (mtROS) production, which promotes the formation and activation of NLRP3 inflammasomes and subsequent pyroptosis. In NPC patients, better local recurrence-free survival was significantly associated with high-level expression of NDUFB8 (p = 0.037) and ATP5B (p = 0.029), as examined using immunohistochemistry. However, there were no significant associations between the expression of NDUFB8 and ATP5B with overall survival of NPC patients. Together, our results demonstrate that up-regulated mitochondrial OxPhos components are strongly associated with NLRP3 inflammasome activation in NPC. Our findings further suggest that high-level expression of OxPhos components could be markers for local recurrence and/or promising therapeutic targets in patients with NPC.

Trichothecenes are a large family of chemically related mycotoxins. Deoxynivalenol (DON), T-2 and HT-2 toxins belong to this family and are produced by various species of Fusarium. The H295R steroidogenesis assay, regulation of steroidogenic gene expression and reporter gene assays (RGAs) for the detection of androgen, estrogen, progestagen and glucocorticoid (ant) agonist responses, have been used to assess the endocrine disrupting activity of DON, T-2 and HT-2 toxins. H295R cells were used as a model for steroidogenesis and gene expression studies and exposed with either DON (0.1-1000 ng/ml), T-2 toxin (0.0005-5 ng/ml) or HT-2 toxin (0.005-50 ng/ml) for 48 h. We observed a reduction in hormone levels in media of exposed cells following radioimmunoassay. Cell viability was determined by four colorimetric assays and we observed reduced cell viability with increasing toxin concentrations partly explaining the significant reduction in hormone levels at the highest toxin concentration of all three trichothecenes. Thirteen of the 16 steroidogenic genes analyzed by quantitative real time PCR (RT-qPCR) were significantly regulated (P < 0.05) by DON (100 ng/ml), T-2 toxin (0.5 ng/ml) and HT-2 toxin (5 ng/ml) compared to the control, with reference genes (B2M, ATP5B and ACTB). Whereas HMGR and CYP19 were down-regulated, CYP1A1 and CYP21 were up-regulated by all three trichothecenes. DON further up-regulated CYP17, HSD3B2, CYP11B2 and CYP11B1 and down-regulated NR5A1. T-2 toxin caused down-regulation of NR0B1 and NR5A1 whereas HT-2 toxin induced up-regulation of EPHX and HSD17B1 and down-regulation of CYP11A and CYP17. The expressions of MC2R, StAR and HSD17B4 genes were not significantly affected by any of the trichothecenes in the present study. Although the results indicate that there is no evidence to suggest that DON, T-2 and HT-2 toxins directly interact with the steroid hormone receptors to cause endocrine disruption, the present findings indicate that exposure to DON, T-2 toxin and HT-2 toxin have effects on cell viability, steroidogenesis and alteration in gene expression indicating their potential as endocrine disruptors. (C) 2012 Elsevier Ireland Ltd. All rights reserved.