ABSTRACT
The inflammasome is a large multiprotein complex that assembles in the cell cytoplasm in response to stress or pathogenic infection. Its primary function is to defend the cell and promote the secretion of pro-inflammatory cytokines, including IL-1ß and IL-18. Previous research has shown that in immortalized bone marrow-derived macrophages (iBMDMs) inflammasome assembly is dependent on the deacetylase HDAC6 and the aggresome processing pathway (APP), a cellular pathway involved in the disposal of misfolded proteins. Here we used primary BMDMs from mice in which HDAC6 is ablated or impaired and found that inflammasome activation was largely normal. We also used human peripheral blood mononuclear cells and monocyte cell lines expressing a synthetic protein blocking the HDAC6-ubiquitin interaction and impairing the APP and found that inflammasome activation was moderately affected. Finally, we used a novel HDAC6 degrader and showed that inflammasome activation was partially impaired in human macrophage cell lines with depleted HDAC6. Our results therefore show that HDAC6 importance in inflammasome activation is context-dependent.
Subject(s)
Inflammasomes , Leukocytes, Mononuclear , Animals , Humans , Mice , Cell Line , Histone Deacetylase 6/genetics , Histone Deacetylase 6/metabolism , Inflammasomes/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Leukocytes, Mononuclear/metabolism , Macrophages/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Protein Transport/physiologyABSTRACT
Heme dioxygenases oxidize the indole ring of tryptophan to kynurenine which is the first step in the biosynthesis of several important biomolecules like NAD, xanthurenic acid, and picolinic acid. A ferrous heme dioxygen adduct (or FeIII-O2â¢-) is the oxidant, and both the atoms of O2 are inserted in the product and its catalytic function has been difficult to emulate as it is complicated by competing rapid reactions like auto-oxidation and/or formation of the µ-oxo dimer. In situ resonance Raman spectroscopy technique, SERRS-RDE, is used to probe the species accumulated during electrochemical ORR catalyzed by site-isolated imidazole-bound iron porphyrin installed on a self-assembled monolayer covered electrode. These in situ SERRS-RDE data using labeled O2 show that indeed a FeIII-O2â¢- species accumulate on the electrode during ORR between -0.05 and -0.30 V versus Ag/AgCl (satd. KCl) and is reduced by proton coupled electron transfer to a FeIII-OOH species which, on the other hand, builds up on the electrode between -0.20 and -0.40 V versus Ag/AgCl (satd. KCl). This FeIII-OOH species then gives way to a FeIVâO species, which accumulates at -0.50 V versus Ag/AgCl (satd. KCl). When 2,3-dimethylindole is present in the solution and the applied potential is held in the range where FeIII-O2â¢- species accumulate, it gets oxidized to N-(2-acetylphenyl)acetamide retaining both the oxygens from O2 mimicking the reaction of heme dioxygenases. Turnover numbers more than 104 are recorded, establishing this imidazole-bound ferrous porphyrin as a functional model of heme dioxygenases.
Subject(s)
Dioxygenases , Porphyrins , Iron/chemistry , Heme/chemistry , Oxygen/chemistry , Oxidation-Reduction , Catalysis , Ferric Compounds/chemistry , ImidazolesABSTRACT
BACKGROUND: Although decision-makers in health care settings need to read and understand the validity of quantitative reports, they do not always carefully read information on research methods. Presenting the methods in a more structured way could improve the time spent reading the methods and increase the perceived relevance of this important report section. OBJECTIVE: To test the effect of a structured summary of the methods used in a quantitative data report on reading behavior with eye-tracking and measure the effect on the perceived importance of this section. METHODS: A nonrandomized pilot trial was performed in a computer laboratory setting with advanced medical students. All participants were asked to read a quantitative data report; an intervention arm was also shown a textbox summarizing key features of the methods used in the report. Three data-collection methods were used to document reading behavior and the views of participants: eye-tracking (during reading), a written questionnaire, and a face-to-face interview. RESULTS: We included 35 participants, 22 in the control arm and 13 in the intervention arm. The overall time spent reading the methods did not differ between the 2 arms. The intervention arm considered the information in the methods section to be less helpful for decision-making than did the control arm (scores for perceived helpfulness were 4.1 and 2.9, respectively, range 1-10). Participants who read the box more intensively tended to spend more time on the methods as a whole (Pearson correlation 0.81, P=.001). CONCLUSIONS: Adding a structured summary of information on research methods attracted attention from most participants, but did not increase the time spent on reading the methods or lead to increased perceptions that the methods section was helpful for decision-making. Participants made use of the summary to quickly judge the methods, but this did not increase the perceived relevance of this section.
ABSTRACT
BACKGROUND: Quantitative data reports are widely produced to inform health policy decisions. Policymakers are expected to critically assess provided information in order to incorporate the best available evidence into the decision-making process. Many other factors are known to influence this process, but little is known about how quantitative data reports are actually read. We explored the reading behavior of (future) health policy decision-makers, using innovative methods. METHODS: We conducted a computer-assisted laboratory study, involving starting and advanced students in medicine and health sciences, and professionals as participants. They read a quantitative data report to inform a decision on the use of resources for long-term care in dementia in a hypothetical decision scenario. Data were collected through eye-tracking, questionnaires, and a brief interview. Eye-tracking data were used to generate 'heatmaps' and five measures of reading behavior. The questionnaires provided participants' perceptions of understandability and helpfulness as well as individual characteristics. Interviews documented reasons for attention to specific report sections. The quantitative analysis was largely descriptive, complemented by Pearson correlations. Interviews were analyzed by qualitative content analysis. RESULTS: In total, 46 individuals participated [students (85%), professionals (15%)]. Eye-tracking observations showed that the participants spent equal time and attention for most parts of the presented report, but were less focused when reading the methods section. The qualitative content analysis identified 29 reasons for attention to a report section related to four topics. Eye-tracking measures were largely unrelated to participants' perceptions of understandability and helpfulness of the report. CONCLUSIONS: Eye-tracking data added information on reading behaviors that were not captured by questionnaires or interviews with health decision-makers.
Subject(s)
Laboratories , Policy Making , Computers , Health Policy , Humans , Research DesignABSTRACT
Despite its murderous act, carbon monoxide (CO) is found to be a very crucial small gaseous messenger molecule in dictating prime biological and physiological processes. Determination of endogenous or exhaled CO levels can throw significant light on smoking status and can be used as a breath biomarker of inflammatory diseases. Therefore, fluorescence imaging of CO in biofluids will empower one with the minute details of various disease states that involve CO. Unfortunately, such efficient fluorescent probes are less in number and also associated with tedious protocols. This enticed our attention and inspired us to look upon developing perceptive imaging agents for CO in a living system. In this report, a resorufin-based "turn-on" orange emissive molecular probe has been successfully utilized to detect CO in an aqueous system. The mono protection of a resorufin unit with an allyl chloroformate furnished a weakly fluorescent small molecular probe P1. Further, the P1+Pd2+ ensemble has been successfully developed in situ using PdCl2 (as Pd2+) and utilized as a light-up signaling mechanism tool for the sensing of CO at the nanomolar level (62 nM) through deprotection mechanism. The probe selectively detects CO without any interference from other anions, gasotransmitters and fatty acids. The present integrated probe P1+Pd2+ system has been found to be highly sensitive to detect CO in cellular systems as well.