• 1 alpha,25-dihydroxyvitamin D3-induced changes in intracellular pH in osteoblast-like cells modulate gene expression

      Jenis, Louis G.; Lian, Jane B.; Stein, Gary S.; Baran, Daniel T. (1993-11-01)
      1 alpha,25-Dihydroxyvitamin D3 exerts rapid nongenomic effects on rat osteoblast-like cells independent of the classic nuclear receptor. These effects include changes in phospholipid metabolism and cell calcium. Intracellular calcium itself has been proposed to regulate intracellular pH in osteoblast cell lines. The purpose of this study was to determine the effect of 1 alpha,25-dihydroxyvitamin D3 on intracellular pH, the relationship of changes in calcium to changes in pH, and the role of pH changes in genomic activation. 1 alpha,25-Dihydroxyvitamin D3 increased intracellular pH within 10 min in rat osteoblast-like cells, an effect that was inhibited by removal of extracellular sodium and by the biologically inactive epimer 1 beta,25-dihydroxyvitamin D3. The hormone increased intracellular calcium in Quin 2 loaded cells in the presence and absence of extracellular sodium. The 1 alpha,25-dihydroxyvitamin D3-induced increments in osteocalcin and osteopontin mRNA levels were abolished in sodium-free medium. The results indicate that 1 alpha,25-dihydroxyvitamin D3-induced increments in cellular calcium precede cell alkalinization and that these changes in intracellular pH may modulate steady-state mRNA levels of genes induced by vitamin D.
    • 1-Deoxysphingolipids cause autophagosome and lysosome accumulation and trigger NLRP3 inflammasome activation

      Lauterbach, Mario A.; Saavedra, Victor; Mangan, Matthew S. J; Penno, Anke; Thiele, Christoph; Latz, Eicke; Kuerschner, Lars (2021-08-01)
      1-Deoxysphingolipids (deoxySLs) are atypical sphingolipids of clinical relevance as they are elevated in plasma of patients suffering from hereditary sensory and autonomic neuropathy (HSAN1) or type 2 diabetes. Their neurotoxicity is described best but they inflict damage to various cell types by an uncertain pathomechanism. Using mouse embryonic fibroblasts and an alkyne analog of 1-deoxysphinganine (doxSA), the metabolic precursor of all deoxySLs, we here study the impact of deoxySLs on macroautophagy/autophagy, the regulated degradation of dysfunctional or expendable cellular components. We find that deoxySLs induce autophagosome and lysosome accumulation indicative of an increase in autophagic flux. The autophagosomal machinery targets damaged mitochondria that have accumulated N-acylated doxSA metabolites, presumably deoxyceramide and deoxydihydroceramide, and show aberrant swelling and tubule formation. Autophagosomes and lysosomes also interact with cellular lipid aggregates and crystals that occur upon cellular uptake and N-acylation of monomeric doxSA. As crystals entering the lysophagosomal apparatus in phagocytes are known to trigger the NLRP3 inflammasome, we also treated macrophages with doxSA. We demonstrate the activation of the NLRP3 inflammasome by doxSLs, prompting the release of IL1B from primary macrophages. Taken together, our data establish an impact of doxSLs on autophagy and link doxSL pathophysiology to inflammation and the innate immune system.Abbreviations: alkyne-doxSA: (2S,3R)-2-aminooctadec-17yn-3-ol; alkyne-SA: (2S,3R)-2- aminooctadec-17yn-1,3-diol; aSA: alkyne-sphinganine; ASTM-BODIPY: azido-sulfo-tetramethyl-BODIPY; CerS: ceramide synthase; CMR: clonal macrophage reporter; deoxySLs: 1-deoxysphingolipids; dox(DH)Cer: 1-deoxydihydroceramide; doxCer: 1-deoxyceramide; doxSA: 1-deoxysphinganine; FB1: fumonisin B1; HSAN1: hereditary sensory and autonomic neuropathy type 1; LC3: MAP1LC3A and MAP1LC3B; LPS: lipopolysaccharide; MEF: mouse embryonal fibroblasts; MS: mass spectrometry; N3635P: azido-STAR635P; N3Cy3: azido-cyanine 3; N3picCy3: azido-picolylcyanine 3; NLRP3: NOD-like receptor pyrin domain containing protein 3; P4HB: prolyl 4-hydroxylase subunit beta; PINK1: PTEN induced putative kinase 1; PYCARD/ASC: PYD and CARD domain containing; SPTLC1: serine palmitoyltransferase long chain base subunit 1; SQSTM1: sequestosome 1; TLC: thin layer chromatography.
    • 1274: Pediatric Critical Care Transfusion and Anemia Expertise Initiative

      Valentine, Stacey L.; Bateman, Scot T.; Bembea, Melania; Doctor, Allan; Lacroix, Jacques; Spinella, Philip C.; Tucci, Marisa; Hassan, Nabil (2016-12-01)
      Abstract no. 1974 for the Critical Care Congress, Research Snapshot Theater: Quality and Safety XXV.
    • 13-cis-retinoic acid suppresses hippocampal cell division and hippocampal-dependent learning in mice

      Crandall, James E.; Sakai, Yasuo; Zhang, Jinhua; Koul, Omanand; Mineur, Yann; Crusio, Wim E.; McCaffery, Peter J. (2004-03-31)
      The active component of the acne drug Accutane is 13-cis-retinoic acid (RA), and it is highly teratogenic for the developing central nervous system. Very little is known, however, regarding the effect of this drug on the adult brain. Regions of the brain that may be susceptible to RA are those that continue to generate new neurons. In the adult mouse, neurogenesis is maintained in the hippocampus and subventricular zone. This report demonstrates that a clinical dose (1 mg/kg/day) of 13-cis-RA in mice significantly reduces cell proliferation in the hippocampus and the subventricular zone, suppresses hippocampal neurogenesis, and severely disrupts capacity to learn a spatial radial maze task. The results demonstrate that the regions of the adult brain where cell proliferation is ongoing are highly sensitive to disruption by a clinical dose of 13-cis-RA.
    • 1alpha,25-dihydroxy vitamin D(3) induces nuclear matrix association of the 1alpha,25-dihydroxy vitamin D(3) receptor in osteoblasts independently of its ability to bind DNA

      Arriagada, Gloria; Paredes, Roberto; Van Wijnen, Andre J.; Lian, Jane B.; van Zundert, Brigitte; Stein, Gary S.; Stein, Janet L.; Montecino, Martin A. (2010-02-04)
      1alpha,25-dihydroxy vitamin D(3) (vitamin D(3)) has an important role during osteoblast differentiation as it directly modulates the expression of key bone-related genes. Vitamin D(3) binds to the vitamin D(3) receptor (VDR), a member of the superfamily of nuclear receptors, which in turn interacts with transcriptional activators to target this regulatory complex to specific sequence elements within gene promoters. Increasing evidence demonstrates that the architectural organization of the genome and regulatory proteins within the eukaryotic nucleus support gene expression in a physiological manner. Previous reports indicated that the VDR exhibits a punctate nuclear distribution that is significantly enhanced in cells grown in the presence of vitamin D(3). Here, we demonstrate that in osteoblastic cells, the VDR binds to the nuclear matrix in a vitamin D(3)-dependent manner. This interaction of VDR with the nuclear matrix occurs rapidly after vitamin D(3) addition and does not require a functional VDR DNA-binding domain. Importantly, nuclear matrix-bound VDR colocalizes with its transcriptional coactivator DRIP205/TRAP220/MED1 which is also matrix bound. Together these results indicate that after ligand stimulation the VDR rapidly enters the nucleus and associates with the nuclear matrix preceding vitamin D(3)-transcriptional upregulation.
    • 2'-O-Methyl at 20-mer Guide Strand 3' Termini May Negatively Affect Target Silencing Activity of Fully Chemically Modified siRNA

      Davis, Sarah M.; Sousa, Jacquelyn; Vangjeli, Lorenc; Hassler, Matthew R.; Echeverria, Dimas; Knox, Emily G.; Turanov, Anton A.; Alterman, Julia F.; Khvorova, Anastasia (2020-09-04)
      Small interfering RNAs (siRNAs) have the potential to treat a broad range of diseases. siRNAs need to be extensively chemically modified to improve their bioavailability, safety, and stability in vivo. However, chemical modifications variably impact target silencing for different siRNA sequences, making the activity of chemically modified siRNA difficult to predict. Here, we systematically evaluated the impact of 3' terminal modifications (2'-O-methyl versus 2'-fluoro) on guide strands of different length and showed that 3' terminal 2'-O-methyl modification negatively impacts activity for >60% of siRNA sequences tested but only in the context of 20- and not 19- or 21-nt-long guide strands. These results indicate that sequence, modification pattern, and structure may cooperatively affect target silencing. Interestingly, the introduction of an extra 2'-fluoro modification in the seed region at guide strand position 5, but not 7, may partially compensate for the negative impact of 3' terminal 2'-O-methyl modification. Molecular modeling analysis suggests that 2'-O-methyl modification may impair guide strand interactions within the PAZ domain of argonaute-2, which may affect target recognition and cleavage, specifically when guide strands are 20-nt long. Our findings emphasize the complex nature of modified RNA-protein interactions and contribute to design principles for chemically modified siRNAs.
    • 2,3,7,8-Tetrachlorodibenzo-p-dioxin inhibits differentiation of normal diploid rat osteoblasts in vitro

      Gierthy, John F.; Silkworth, J. B.; Tassinari, Melissa S.; Stein, Gary S.; Lian, Jane B. (1994-02-01)
      The influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent halogenated aromatic hydrocarbon, on the development of bone tissue-like organization in primary cultures of normal diploid calvarial-derived rat osteoblasts was examined. Initially, when placed in culture, these cells actively proliferate while expressing genes associated with biosynthesis of the bone extracellular matrix. Then, post-proliferatively, genes are expressed that render the osteoblast competent for extracellular matrix mineralization and maintenance of structural as well as functional properties of the mature bone-cell phenotype. Our results indicate that, in the presence of TCDD, proliferation of osteoblasts was not inhibited but post-confluent formation of multicellular nodules that develop bone tissue-like organization was dramatically suppressed. Consistent with TCDD-mediated abrogation of bone nodule formation, expression of alkaline phosphatase and osteocalcin was not upregulated post-proliferatively. These findings are discussed within the context of TCDD effects on estrogens and vitamin D-responsive developmental gene expression during osteoblast differentiation and, from a broader biological perspective, on steroid hormone control of differentiation.
    • 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative

      Aletaha, Daniel; Neogi, Tuhina; Silman, Alan J.; Funovits, Julia; Felson, David T.; Bingham, Clifton O. III; Birnbaum, Neal S.; Burmester, Gerd R.; Bykerk, Vivian P.; Cohen, Marc D.; et al. (2010-09-01)
      OBJECTIVE: The 1987 American College of Rheumatology (ACR; formerly, the American Rheumatism Association) classification criteria for rheumatoid arthritis (RA) have been criticized for their lack of sensitivity in early disease. This work was undertaken to develop new classification criteria for RA. METHODS: A joint working group from the ACR and the European League Against Rheumatism developed, in 3 phases, a new approach to classifying RA. The work focused on identifying, among patients newly presenting with undifferentiated inflammatory synovitis, factors that best discriminated between those who were and those who were not at high risk for persistent and/or erosive disease--this being the appropriate current paradigm underlying the disease construct "rheumatoid arthritis." RESULTS: In the new criteria set, classification as "definite RA" is based on the confirmed presence of synovitis in at least 1 joint, absence of an alternative diagnosis that better explains the synovitis, and achievement of a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains: number and site of involved joints (score range 0-5), serologic abnormality (score range 0-3), elevated acute-phase response (score range 0-1), and symptom duration (2 levels; range 0-1). CONCLUSION: This new classification system redefines the current paradigm of RA by focusing on features at earlier stages of disease that are associated with persistent and/or erosive disease, rather than defining the disease by its late-stage features. This will refocus attention on the important need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent or minimize the occurrence of the undesirable sequelae that currently comprise the paradigm underlying the disease construct "rheumatoid arthritis."
    • 2017 AAAEM Benchmarking Survey: Comparing Pediatric and Adult Academic Emergency Departments

      Rathlev, Niels K.; Holt, Nate M.; Harbertson, Cathi A.; Hettler, Joeli; Reznek, Martin A.; Tsai, Shiu-Lin; Lopiano, Kenny K.; Bohrmann, Tommy; Scheulen, James J. (2020-01-21)
      OBJECTIVES: The Academy of Administrators in Academic Emergency Medicine Benchmark Survey of academic emergency departments (EDs) was conducted in 2017. We compared operational measures between pediatric and adult (defined as fewer than 5% pediatric visits) EDs based on survey data. Emergency departments in dedicated pediatric hospitals were not represented. METHODS: Measures included: (1) patient volumes, length of stay, and acuity; and 2) faculty staffing, productivity, and percent effort in academics. t Tests were used to compare continuous measures and inferences for categorical variables were made using Pearson chi test. RESULTS: The analysis included 17 pediatric and 52 adult EDs. We found a difference in the number of annual visits between adult (median, 66,275; interquartile range [IQR], 56,184-77,702) and pediatric EDs (median, 25,416; IQR, 19,840-29,349) (P < 0.0001). Mean "arrivals per faculty clinical hour" and "total arrivals per treatment space" showed no differences. The proportion of visits (1) arriving by emergency medical services and (2) for behavioral health were significantly higher in adult EDs (both P < 0.0001). The mean length of stay in hours for "all" patients was significantly longer in adult (5.4; IQR, 5.0-6.6) than in pediatric EDs (3.5; IQR, 2.9-4.3; P = 0.017). A similar difference was found for "discharged" patients (P = 0.004). Emergency severity indices, professional evaluation and management codes, and hospitalization rates all suggest higher acuity in adult EDs (all P < 0.0001). There were no differences in mean work relative value units per patient or in the distribution of full time equivalent effort dedicated to academics. CONCLUSIONS: In this cohort, significant differences in operational measures exist between academic adult and pediatric EDs. No differences were found when considering per unit measures, such as arrivals per faculty clinical hour or per treatment space.
    • 3-Hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin)-induced 28-kDa interleukin-1beta interferes with mature IL-1beta signaling

      Davaro, Facundo; Forde, Sorcha D.; Garfield, Mark; Jiang, Zhaozhao; Halmen, Kristen A.; Tamburro, Nelsy DePaula; Kurt-Jones, Evelyn A.; Fitzgerald, Katherine A.; Golenbock, Douglas T.; Wang, Donghai (2014-06-06)
      Multiple clinical trials have shown that the 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors known as statins have anti-inflammatory effects. However, the underlying molecular mechanism remains unclear. The proinflammatory cytokine interleukin-1beta (IL-1beta) is synthesized as a non-active precursor. The 31-kDa pro-IL-1beta is processed into the 17-kDa active form by caspase-1-activating inflammasomes. Here, we report a novel signaling pathway induced by statins, which leads to processing of pro-IL-1beta into an intermediate 28-kDa form. This statin-induced IL-1beta processing is independent of caspase-1- activating inflammasomes. The 28-kDa form of IL-1beta cannot activate interleukin-1 receptor-1 (IL1R1) to signal inflammatory responses. Instead, it interferes with mature IL-1beta signaling through IL-1R1 and therefore may dampen inflammatory responses initiated by mature IL-1beta. These results may provide new clues to explain the anti-inflammatory effects of statins.
    • 3-Methyladenine DNA glycosylase activity in a glial cell line sensitive to the haloethylnitrosoureas in comparison with a resistant cell line

      Matijasevic, Zdenka; Bodell, William J.; Ludlum, David B. (1991-03-01)
      Extracts of a glial cell line (SF-126) which is sensitive to the cytotoxic effect of the haloethylnitrosoureas and of a cell line (SF-188) which is resistant to these agents have been tested for their ability to release methylated bases from a DNA substrate which has been modified with [3H]dimethyl sulfate. In comparison with the sensitive cell line, extracts from the resistant cell line have 2-3-fold higher enzymatic activity. High performance liquid chromatography profiles of the bases which are released by these extracts show that the activity is specific for 3-methyladenine, suggesting that the resistant cells contain elevated levels of 3-methyladenine DNA glycosylase. Previous studies have shown that these cells also contain elevated levels of O6-alkylguanine-DNA alkyl-transferase, suggesting that both enzyme activities may be involved in the resistance of this cell line to the haloethylnitrosoureas.
    • 30-year trends in patient characteristics, treatment practices, and long-term outcomes of adults aged 35 to 54 years hospitalized with acute myocardial infarction

      Tisminetzky, Mayra; McManus, David D.; Gore, Joel M.; Yarzebski, Jorge L.; Coles, Andrew H.; Lessard, Darleen M.; Goldberg, Robert J. (2014-04-01)
      Much of our knowledge about the characteristics, clinical management, and postdischarge outcomes of acute myocardial infarction (AMI) is derived from clinical studies in middle-aged and older subjects with little contemporary information available about the descriptive epidemiology of AMI in relatively young men and women. The objectives of our population-based study were to describe >3-decade-long trends in the clinical features, treatment practices, and long-term outcomes of young adults aged 35 to 54 years discharged from the hospital after AMI. The study population consisted of 2,142 residents of the Worcester (Massachusetts) metropolitan area who were hospitalized with AMI at all central Massachusetts medical centers during 16 annual periods from 1975 to 2007. Our primarily male study population had an average age of 47 years. Patients hospitalized during the most recent decade (1997 to 2007) under study were more likely to have a history of hypertension and heart failure than those hospitalized during earlier study years. Patients were less likely to have developed heart failure or stroke during their hospitalization in the most recent compared with the initial decade under study (heart failure 13.7% and stroke 0.7% vs 20.9% and 2.0%, respectively). One- and 2-year postdischarge death rates also decreased significantly between 1975 to 1986 (6.2% and 9.0%, respectively) and 1988 to 1995 (2.6% and 4.9%). These trends were concomitant with the increasing use of effective cardiac therapies and coronary interventions during hospitalization. The present results provide insights into the changing characteristics, management, and improving long-term outcomes of relatively young patients hospitalized with AMI.
    • 3C-Based Chromatin Interaction Analyses

      Kim, Tae Hoon; Dekker, Job (2018-09-04)
      This introduction presents a molecular approach that uses formaldehyde cross-linking to investigate genome structure and function-chromosome conformation capture (3C). This approach allows us to determine the spatial proximity of distant functional genomic sites (by looping). 3C-based techniques to interrogate chromosome folding and long-range interactions between genomic sequences in vivo are detailed.
    • 3C-based technologies to study the shape of the genome

      de Laat, Wouter; Dekker, Job (2012-11-01)
      Guest editors' introduction to November 2012 issue of Methods, which provides detailed and up-to-date lab protocols of the many 3C (chromosome conformation capture) methodologies, provided by expert groups that often first pioneered these technologies.
    • 4-D Reconstruction With Respiratory Correction for Gated Myocardial Perfusion SPECT

      Qi, Wenyuan; Yang, Yongyi; Song, Chao; Wernick, Miles N.; Pretorius, P. Hendrik; King, Michael A. (2017-08-01)
      Cardiac single photon emission computed tomography (SPECT) images are known to suffer from both cardiac and respiratory motion blur. In this paper, we investigate a 4-D reconstruction approach to suppress the effect of respiratory motion in gated cardiac SPECT imaging. In this approach, the sequence of cardiac gated images is reconstructed with respect to a reference respiratory amplitude bin in the respiratory cycle. To combat the challenge of inherent high-imaging noise, we utilize the data counts acquired during the entire respiratory cycle by making use of a motion-compensated scheme, in which both cardiac motion and respiratory motion are taken into account. In the experiments, we first use Monte Carlo simulated imaging data, wherein the ground truth is known for quantitative comparison. We then demonstrate the proposed approach on eight sets of clinical acquisitions, in which the subjects exhibit different degrees of respiratory motion blur. The quantitative evaluation results show that the 4-D reconstruction with respiratory correction could effectively reduce the effect of motion blur and lead to a more accurate reconstruction of the myocardium. The mean-squared error of the myocardium is reduced by 22%, and the left ventricle (LV) resolution is improved by 21%. Such improvement is also demonstrated with the clinical acquisitions, where the motion blur is markedly improved in the reconstructed LV wall and blood pool. The proposed approach is also noted to be effective on correcting the spill-over effect in the myocardium from nearby bowel or liver activities.
    • 40-year-old Female with Sudden Onset Dyspnea

      Kebort, Breanna M.; Hong, Aleta; Bontempo, Laura J.; Dezman, Zachary D. W. (2021-02-01)
      A 40-year-old female presented to the emergency department (ED) after the acute onset of dyspnea. The patient was tachypneic with accessory muscle usage and diffuse wheezing on initial examination. Despite aggressive treatment, the patient deteriorated and was intubated. This case takes the reader through the differential diagnosis and systematic workup of a patient presenting to the ED with dyspnea and arrives at the unexpected cause for this patient's presentation.
    • 4C Analysis of 3C, ChIP-Loop, and Control Libraries

      Kim, Tae Hoon; Dekker, Job (2018-09-04)
      The 4C detection method starts with a 3C, ChIP-loop, or control library and then uses inverse polymerase chain reaction (PCR) to amplify all restriction fragments that are ligated to a single restriction fragment of interest. As a result, a genome-wide interaction profile of the restriction fragment of interest is obtained. Before starting a 4C experiment, first assess the quality of the 3C, ChIP-loop, or control library that will be studied by performing semiquantitative PCR with the library as template. This procedure ascertains that ligation products can be readily detected and that nearby restriction fragments become ligated more frequently than more distant fragments. Choice of a restriction enzyme for 4C analysis and determination of interaction frequencies using 4C are described in detail.
    • 5 Year Expression and Neutrophil Defect Repair after Gene Therapy in Alpha-1 Antitrypsin Deficiency

      Mueller, Christian; Gernoux, Gwladys; Gruntman, Alisha M.; Borel, Florie; Reeves, Emer P.; Calcedo, Roberto; Rouhani, Farshid N.; Yachnis, Anthony; Humphries, Margaret; Campbell-Thompson, Martha; et al. (2017-06-07)
      Alpha-1 antitrypsin deficiency is a monogenic disorder resulting in emphysema due principally to the unopposed effects of neutrophil elastase. We previously reported achieving plasma wild-type alpha-1 antitrypsin concentrations at 2.5%-3.8% of the purported therapeutic level at 1 year after a single intramuscular administration of recombinant adeno-associated virus serotype 1 alpha-1 antitrypsin vector in alpha-1 antitrypsin deficient patients. We analyzed blood and muscle for alpha-1 antitrypsin expression and immune cell response. We also assayed previously reported markers of neutrophil function known to be altered in alpha-1 antitrypsin deficient patients. Here, we report sustained expression at 2.0%-2.5% of the target level from years 1-5 in these same patients without any additional recombinant adeno-associated virus serotype-1 alpha-1 antitrypsin vector administration. In addition, we observed partial correction of disease-associated neutrophil defects, including neutrophil elastase inhibition, markers of degranulation, and membrane-bound anti-neutrophil antibodies. There was also evidence of an active T regulatory cell response (similar to the 1 year data) and an exhausted cytotoxic T cell response to adeno-associated virus serotype-1 capsid. These findings suggest that muscle-based alpha-1 antitrypsin gene replacement is tolerogenic and that stable levels of M-AAT may exert beneficial neutrophil effects at lower concentrations than previously anticipated.
    • 5,6-Dimethylxanthenone-4-acetic acid (DMXAA) activates stimulator of interferon gene (STING)-dependent innate immune pathways and is regulated by mitochondrial membrane potential

      Prantner, Daniel; Perkins, Darren J.; Lai, Wendy; Williams, Mark S.; Sharma, Shrutie; Fitzgerald, Katherine A.; Vogel, Stefanie N. (2012-11-16)
      The chemotherapeutic agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is a potent inducer of type I IFNs and other cytokines. This ability is essential for its chemotherapeutic benefit in a mouse cancer model and suggests that it might also be useful as an antiviral agent. However, the mechanism underlying DMXAA-induced type I IFNs, including the host proteins involved, remains unclear. Recently, it was reported that the antioxidant N-acetylcysteine (NAC) decreased DMXAA-induced TNF-alpha and IL-6, suggesting that oxidative stress may play a role. The goal of this study was to identify host proteins involved in DMXAA-dependent signaling and determine how antioxidants modulate this response. We found that expression of IFN-beta in response to DMXAA in mouse macrophages requires the mitochondrial and endoplasmic reticulum resident protein STING. Addition of the antioxidant diphenylene iodonium (DPI) diminished DMXAA-induced IFN-beta, but this decrease was independent of both the NADPH oxidase, Nox2, and de novo generation of reactive oxygen species. Additionally, IFN-beta up-regulation by DMXAA was inhibited by agents that target the mitochondrial electron transport chain and, conversely, loss of mitochondrial membrane potential correlated with diminished innate immune signaling in response to DMXAA. Up-regulation of Ifnb1 gene expression mediated by cyclic dinucleotides was also impaired by DPI, whereas up-regulation of Ifnb1 mRNA due to cytosolic double-stranded DNA was not. Although both stimuli signal through STING, cyclic dinucleotides interact directly with STING, suggesting that recognition of DMXAA by STING may also be mediated by direct interaction.
    • 5-Fluorouracil-associated cardiotoxicity

      Freeman, N. J.; Costanza, Mary E. (1988-01-01)
      Cardiotoxicity manifested as myocardial ischemia is not generally recognized as a side effect of 5-fluorouracil. However, there have been at least 35 cases reported since 1975. In only one of these cases was a somewhat detailed evaluation done to rule out underlying coronary disease. The case reported here of 5-FU cardiotoxicity included an extensive cardiac evaluation to rule out underlying coronary disease and to assess spasm. The literature on 5-FU cardiotoxicity is also reviewed, and its possible mechanisms are analyzed.