27 research outputs found
Macropinocytosis of Extracellular Glutathione Ameliorates Tumor Necrosis Factor α Release in Activated Macrophages
A number of inflammatory lung diseases have abnormally low glutathione (GSH) levels in the airway fluids. Lung macrophages are common mediators of inflammation, make up the majority of cells that are found in the airway epithelial lining fluid (ELF), and are commonly elevated in many lung diseases. Several animal models with altered ELF GSH levels are associated with similar alterations in the intracellular GSH levels of bronchoalveolar lavage (BAL) cells. The possible mechanisms and outcomes for this association between ELF GSH levels and intracellular BAL cell GSH are unknown. To investigate these issues, macrophages were grown in media supplemented with 500 µM GSH. GSH supplementation resulted in a 2–3 fold increase in macrophage intracellular GSH levels. The increase in macrophage intracellular GSH levels was associated with a significant reduction in NF-κB nuclear translocation and tumor necrosis factor α (TNFα) release upon LPS stimulation. Furthermore, co-treatment of macrophages with GSH and inhibitors of GSH breakdown or synthesis did not block GSH accumulation. In contrast, treatment with cytochalasin D, an inhibitor of actin dependent endocytosis, and amiloride, an inhibitor of macropinocytosis blocked, at least in part, GSH uptake. Furthermore, using two cigarette smoke exposure paradigms that result in two different GSH levels in the ELF and thus in the BAL cells resulted in modulation of cytokine release when stimulated with LPS ex vivo. These data suggest that macrophages are able to utilize extracellular GSH which can then modulate inflammatory signaling in response to proinflammatory stimuli. This data also suggests the lung can modulate inflammatory responses triggered by proinflammatory stimuli by altering ELF GSH levels and may help explain the dysregulated inflammation associated with lung diseases that have low ELF GSH levels
Hypertonic saline increases lung epithelial lining fluid glutathione and thiocyanate: two protective CFTR-dependent thiols against oxidative injury
<p>Abstract</p> <p>Background</p> <p>Cystic fibrosis is a debilitating lung disease due to mutations in the cystic fibrosis transmembrane conductance regulator protein (CFTR) and is associated with chronic infections resulting in elevated myeloperoxidase activity and generation of hypochlorous acid (HOCl). CFTR mutations lead to decreased levels of glutathione (GSH) and thiocyanate (SCN) in the epithelial lining fluid (ELF). Hypertonic saline is used to improve lung function however the mechanism is uncertain.</p> <p>Methods</p> <p>In the present study, the effect of GSH and SCN on HOCl-mediated cell injury and their changes in the ELF after hypertonic saline nebulization in wild type (WT) and CFTR KO mice was examined. CFTR sufficient and deficient lung cells were assessed for GSH, SCN and corresponding sensitivity towards HOCl-mediated injury, in vitro.</p> <p>Results</p> <p>CFTR (-) cells had lower extracellular levels of both GSH and SCN and were more sensitive to HOCl-mediated injury. In vivo, hypertonic saline increased ELF GSH in the WT and to a lesser extent in the CFTR KO mice but only SCN in the WT ELF. Finally, potential protective effects of GSH and SCN at concentrations found in the ELF against HOCl toxicity were examined in vitro.</p> <p>Conclusions</p> <p>While the concentrations of GSH and SCN associated with the WT ELF protect against HOCl toxicity, those found in the CFTR KO mice were less sufficient to inhibit cell injury. These data suggests that CFTR has important roles in exporting GSH and SCN which are protective against oxidants and that hypertonic saline treatment may have beneficial effects by increasing their levels in the lung.</p
Mechanical Thrombectomy for Acute Stroke: Early versus Late Time Window Outcomes
BACKGROUND AND PURPOSERecent trials have shown benefit of thrombectomy in patients selected by penumbral imaging in the late (>6 hours) window. However, the role penumbral imaging is not clear in the early (0‐6 hours) window. We sought to evaluate if time to treatment modifies the effect of endovascular reperfusion in stroke patients with evidence of salvageable tissue on CT perfusion (CTP).METHODSWe retrospectively analyzed consecutive patients who underwent thrombectomy in a single center. Demographics, comorbidities, National Institute of Health Stroke Scale (NIHSS), rtPA administration, ASPECTS, core infarct volume, onset to skin puncture time, recanalization (mTICI IIb/III), final infarct volume were compared between patients with good and poor 90‐day outcomes (mRS 0‐2 vs. 3‐6). Multivariable logistic regression analyses were used to identify independent predictors of a good (mRS 0‐2) 90‐day outcome.RESULTSA total of 235 patients were studied, out of which 52.3% were female. Univariate analysis showed that the groups (early vs. late) were balanced for age (P = .23), NIHSS (P = .63), vessel occlusion location (P = .78), initial core infarct volume (P = .15), and recanalization (mTICI IIb/III) rates (P = .22). Favorable outcome (mRS 0‐2) at 90 days (P = .30) were similar. There was a significant difference in final infarct volume (P = .04). Shift analysis did not reveal any significant difference in 90‐day outcome (P = .14). After adjustment; age (P < .001), NIHSS (P = .01), recanalization (P = .008), and final infarct volume (P < .001) were predictive of favorable outcome.CONCLUSIONSPenumbral imaging‐based selection of patients for thrombectomy is effective regardless of onset time and yields similar functional outcomes in early and late window patients.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155458/1/jon12698_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155458/2/jon12698.pd
The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019
Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe
Role for Cystic Fibrosis Transmembrane Conductance Regulator Protein in a Glutathione Response to Bronchopulmonary Pseudomonas Infection
The lung maintains an elevated level of glutathione (GSH) in epithelial lining fluid (ELF) compared to serum. The mechanism(s) by which the lung maintains high levels of ELF GSH and factors that modulate them are largely unexplored. We hypothesized that lung cystic fibrosis transmembrane conductance regulator protein (CFTR) modulates GSH efflux in response to extracellular stress, which occurs with lung infections. Mice were challenged intratracheally with Pseudomonas aeruginosa, and on the third day of infection bronchoalveolar lavage fluid was obtained and analyzed for cytokines and antioxidants. Lung tissue antioxidants and enzyme activities were also assessed. P. aeruginosa lung infection increased levels of inflammatory cytokines and neutrophils in the ELF. This corresponded with a marked threefold increase in GSH and a twofold increase in urate levels in the ELF of P. aeruginosa-infected wild-type mice. A twofold increase in urate levels was also observed among lung tissue antioxidants of P. aeruginosa-infected wild-type mice. There were no changes in markers of lung oxidative stress associated with the P. aeruginosa lung infection. In contrast with wild-type mice, the CFTR knockout mice lacked a significant increase in ELF GSH when challenged with P. aeruginosa, and this correlated with a decrease in the ratio of reduced to oxidized GSH in the ELF, a marker of oxidative stress. These data would suggest that the lung adapts to infectious agents with elevated ELF GSH and urate. Individuals with lung diseases associated with altered antioxidant transport, such as cystic fibrosis, might lack the ability to adapt to the infection and present with a more severe inflammatory response
Anti-inflammatory effects of GSH are dependent on macropinocytosis.
<p>Brighfield images of control (A), fluorescent labeled GSH (Fl-GSH) (B) or Fl-GSH with cytochalasin D (C) provide further evidence for the direct uptake of extracellular GSH. Furthermore, LPS induced TNFα release was examined after supplementation with GSH and/or cytochalasin D to block that uptake (D). Data represented as mean ± SEM, with ***p<0.001 compared to either LPS only.</p
Extracellular GSH alters intracellular levels.
<p>J774 (A), or primary alveolar macrophages (B) were grown in media supplemented with or without 500 µM GSH and intracellular GSH levels were measured. Data represented as mean ± SEM, with ***p<0.001.</p
In vivo uptake of fluorescent labeled GSH.
<p>Fluorescent labeled GSH (Fl-GSH) was administered intratracheally and examined after a period of 2 h. Representative image of BAL cells recovered from control (A) and Fl-GSH (B) administered mice. Quantization of resulting Fl-GSH concentrations 2 h after administration (C), control samples contain no detectable fluorescence.</p
Altered GSH status in the airways results in different cytokine response to LPS.
<p>Alveolar macrophages were obtained from mice sampled immediately after a 2 h (closed bars) cigarette smoke (CS) exposure or 24 h (open bars) recovery from CS exposure and treated with LPS for 2 h. TNFα release was measured by ELISA. Data represented as mean ± SEM, with ***p<0.001 compared between 2 h CS and 1 d CS.</p