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BACKGROUND: Chronic immunosuppression following pancreas transplantation carries significant risk, including posttransplant lymphoproliferative disease (PTLD). We sought to define the incidence, risk factors, and long-term outcomes of PTLD following pancreas transplantation at a single center. METHODS: All adult pancreas transplants between February 1, 1983 and December 31, 2023 at the University of Minnesota were reviewed, including pancreas transplant alone (PTA), simultaneous pancreas-kidney transplants (SPK), and pancreas after kidney transplants (PAK). RESULTS: Among 2353 transplants, 110 cases of PTLD were identified, with an overall incidence of 4.8%. 17.3% were diagnosed within 1 year of transplant, 32.7% were diagnosed within 5 years, and 74 (67.3%) were diagnosed after 5 years. The overall 30-year incidence of PTLD did not differ by transplant type-7.4% for PTA, 14.2% for SPK, and 19.4% for PAK (p = 0.3). In multivariable analyses, older age and Epstein-Barr virus seronegativity were risk factors for PTLD, and PTLD was a risk factor for patient death. PTLD-specific mortality was 32.7%, although recipients with PTLD had similar median posttransplant survival compared to those without PTLD (14.9 year vs. 15.6 year, p = 0.9). CONCLUSIONS: PTLD following pancreas transplantation is associated with significant mortality. Although the incidence of PTLD has decreased over time, a high index of suspicion for PTLD following PTx should remain in EBV-negative recipients.
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Sobrevivência de Enxerto , Transtornos Linfoproliferativos , Transplante de Pâncreas , Complicações Pós-Operatórias , Humanos , Transplante de Pâncreas/efeitos adversos , Masculino , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/epidemiologia , Feminino , Adulto , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Seguimentos , Fatores de Risco , Prognóstico , Pessoa de Meia-Idade , Incidência , Taxa de Sobrevida , Estudos Retrospectivos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/mortalidade , Transplante de Rim/efeitos adversos , Adulto JovemRESUMO
Introduction: African Americans (AA) are widely underrepresented in plasma biomarker studies for Alzheimer's disease (AD) and current diagnostic biomarker candidates do not reflect the heterogeneity of AD. Methods: Untargeted proteome measurements were obtained using the SomaScan 7k platform to identify novel plasma biomarkers for AD in a cohort of AA clinically diagnosed as AD dementia (n=183) or cognitively unimpaired (CU, n=145). Machine learning approaches were implemented to identify the set of plasma proteins that yields the best classification accuracy. Results: A plasma protein panel achieved an area under the curve (AUC) of 0.91 to classify AD dementia vs CU. The reproducibility of this finding was observed in the ANMerge plasma and AMP-AD Diversity brain datasets (AUC=0.83; AUC=0.94). Discussion: This study demonstrates the potential of biomarker discovery through untargeted plasma proteomics and machine learning approaches. Our findings also highlight the potential importance of the matrisome and cerebrovascular dysfunction in AD pathophysiology.
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BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) presents a significant global health challenge, particularly among individuals with liver cirrhosis, with hepatitis C (HCV) a major cause. In people with HCV-related cirrhosis, an increased risk of HCC remains after cure. HCC surveillance with six monthly ultrasounds has been shown to improve survival. However, adherence to biannual screening is currently suboptimal. This study aimed to evaluate the effect of increased HCC surveillance uptake and improved ultrasound sensitivity on mortality among people with HCV-related cirrhosis post HCV cure. METHODS: This study utilized mathematical modelling to assess HCC progression, surveillance, diagnosis, and treatment among individuals with cirrhosis who had successfully been treated for HCV. The deterministic compartmental model incorporated Barcelona Clinic Liver Cancer (BCLC) stages to simulate disease progression and diagnosis probabilities in 100 people with cirrhosis who had successfully been treated for hepatitis C over 10 years. Four interventions were modelled to assess their potential for improving life expectancy: realistic improvements to surveillance adherence, optimistic improvements to surveillance adherence, diagnosis sensitivity enhancements, and improved treatment efficacy Results: Realistic adherence improvements resulted in 9.8 (95% CI 7.9, 11.6) life years gained per cohort of 100 over a 10-year intervention period; 17.2 (13.9, 20.3) life years were achieved in optimistic adherence improvements. Diagnosis sensitivity improvements led to a 7.0 (3.6, 13.8) year gain in life years, and treatment improvements improved life years by 9.0 (7.5, 10.3) years. CONCLUSIONS: Regular HCC ultrasound surveillance remains crucial to reduce mortality among people with cured hepatitis C and cirrhosis. Our study highlights that even minor enhancements to adherence to ultrasound surveillance can significantly boost life expectancy across populations more effectively than strategies that increase surveillance sensitivity or treatment efficacy.
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In this Viewpoint, the accuracy, usefulness, and marketing of at-home rape kits is explored.
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Health-related quality of life (HRQoL) measures individual well-being across physical, psychological, and social domains. Patients with predominantly antibody deficiency (PAD) are at risk for morbidity and mortality, however, the effect of these complications on HRQoL requires additional study. Patients with PAD were asked to voluntarily complete the Centers for Disease Control (CDC) HRQoL-14 Healthy Days Measure questionnaire. These results were compared to data from the CDC-initiated Behavioral Risk Factor Surveillance System (BRFSS), a cross-sectional questionnaire including questions from CDC-HRQOL-14. Statistical analyses included two-proportion Z-test, t-tests, and analysis of variance. 83 patients with PAD completed the survey. Patients were sub-stratified into mild (23.7%), moderate (35.5%), severe (40.8%), and secondary (8.4%) PAD. "Fair or poor" health status was reported in 52.6% of PAD patients. Mental health challenges ≥ 14 days/month occurred in 25% of patients. Physical health issues ≥ 14 days/month was reported in 44.7% of patients. Activity limitations were noted by 80.3% of patients. There were no statistically significant differences by PAD severity. Patients with autoimmune and inflammatory disease co-morbidities reported more mental health challenges compared to those without (78% vs. 54.3%, p = 0.02). Compared to the CDC-BRFSS data, significantly more patients with PAD reported "fair or poor" health status (53% vs 12.0%; p < 0.0001), mental health challenges (24.1% vs 14.7%; p = 0.02), and poor physical health (44.6% vs 8.0%; p < 0.0001). Patients with PAD had significantly reduced HRQoL compared to CDC-BRFSS respondents from a similar geographical region. Decreased HRQoL was prevalent across all PAD severity levels. Additional research is needed to improve HRQoL for patients with PAD.
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Qualidade de Vida , Humanos , Estudos Transversais , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Inquéritos e Questionários , Nível de Saúde , Idoso , Adulto Jovem , Síndromes de Imunodeficiência/epidemiologia , Estados Unidos/epidemiologia , AdolescenteAssuntos
Infecções por HIV , Pessoas Mal Alojadas , Desemprego , Humanos , Infecções por HIV/psicologia , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Filipinas/epidemiologia , Pessoas Mal Alojadas/psicologia , Desemprego/psicologia , Masculino , Apoio Social , Feminino , AdultoRESUMO
BACKGROUND AND OBJECTIVE: Protease-activated receptor-1 (PAR1) has emerged as an important link between coagulation and the complications of obesity including metabolic dysfunction-associated steatotic liver disease (MASLD). PAR1 is expressed by various cells and cleaved by different proteases to generate unique tethered agonists that activate distinct signaling pathways. Mice expressing PAR1 with an R41Q mutation have disabled canonical thrombin-mediated signaling, whereas R46Q mice express PAR1 resistant to non-canonical signaling by activated protein C (APC). METHODS: Mice with whole body and hepatocyte-selective PAR1 deficiency, as well as PAR1 R41Q and R46Q mice were fed a high fat diet to induce MASLD. RESULTS AND CONCLUSIONS: High fat diet (HFD)-fed R41Q mice displayed reduced hepatic steatosis and liver/body weight ratio. In contrast, HFD-fed R46Q mice displayed increased relative liver weight and hepatic steatosis alongside increased serum ALT activity. Surprisingly, despite the distinct impact of PAR1 mutations on steatosis, selective deletion of PAR1 in hepatocytes had no impact. To evaluate a viable PAR1-targeted approach, mice with HFD-induced obesity were treated with the allosteric PAR1 modulator NRD-21, which inhibits canonical PAR1 inflammatory signaling but promotes PAR1 protective, non-canonical anti-inflammatory signaling. NRD-21 treatment reduced plasma TNFα, serum ALT activity, hepatic steatosis, and insulin resistance (HOMA-IR), but increased plasma active GLP-1. The results suggest non-hepatocellular canonical PAR1 cleavage drives MASLD in obese mice and provide translational proof-of-concept that selective pharmacological modulation of PAR1 yields multiple metabolic benefits in experimental obesity.
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Background: While growth factors have the potential to halt degeneration and decrease inflammation in animal models, the literature investigating the effect of dosage on human cells is lacking. Moreover, despite the completion of clinical trials using growth differentiation factor-5 (GDF-5), no results have been publicly released. Aims: The overall objective was to quantitatively assess the effect of three clinically relevant concentrations of GDF-5 (0.25, 1, and 2 mg) as a therapeutic for disc regeneration. Materials and methods: Firstly, this work experimentally determined the effects of GDF-5 concentration on the metabolic and matrix synthesis rates of human nucleus pulposus (NP) cells. Secondly, in silico modeling was employed to predict the subsequent regenerative effect of different GDF-5 treatments (± cells). Results: This study suggests a trend of increased matrix synthesis with 0.25 and 1 mg of GDF-5. However, 2 mg of GDF-5 significantly upregulates oxygen consumption. Despite this, in silico models highlight the potential of growth factors in promoting matrix synthesis compared to cell-only treatments, without significantly perturbing the nutrient microenvironment. Discussion: This work elucidates the potential of GDF-5 on human NP cells. Although the results did not reveal statistical differences across all doses, the variability and response among donors is an interesting finding. It highlights the complexity of human response to biological treatments and reinforces the need for further human research and personalized approaches. Furthermore, this study raises a crucial question about whether these potential biologics are more regenerative in nature or better suited as prophylactic therapies for younger patient groups. Conclusion: Biological agents exhibit unique characteristics and features, demanding tailored development strategies and individualized assessments rather than a one-size-fits-all approach. Therefore, the journey to realizing the full potential of biological therapies is long and costly. Nonetheless, it holds the promise of revolutionizing spinal healthcare and improving the quality of life for patients suffering from discogenic back pain.
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INTRODUCTION: A national nicotine reduction policy could reduce the public health toll of smoking. However, reducing nicotine in cigarettes may lead to changes in the use of other tobacco products such as nicotine vaping devices, particularly among young people. Product use outcomes may depend on characteristics of available nicotine vaping devices. We aimed to determine the impact of cigarette nicotine content, vaping device nicotine concentration, and vaping device flavors on choices to smoke, vape, or abstain. METHODS: Early young adults (ages 18-20 inclusive, N=80) who reported smoking daily and vaping nicotine at least twice in their lifetime participated in a laboratory study. Participants received either Very Low Nicotine Content (VLNC; 0.4 mg nicotine/g of tobacco) or Normal Nicotine Content (NNC; 15.8 mg/g) cigarettes. First, participants chose between their assigned cigarette or abstaining. Subsequently, participants chose between 2 cigarette puffs, 2 vape puffs, or abstaining. Vaping device nicotine concentration (3mg vs. 18mg/ml) and flavor (tobacco vs. non-tobacco) were manipulated within-subjects. RESULTS: When only cigarettes were available, there were no differences between the VLNC and NNC groups on cigarette choices. When the nicotine vaping device was concurrently available, the VLNC group made fewer choices to smoke than the NNC group. Non-tobacco flavors and lower vaping device nicotine concentration were associated with fewer choices to smoke. CONCLUSIONS: Nicotine vaping device availability reduced choices to smoke VLNC cigarettes, and vaping devices with lower nicotine and non-tobacco flavors led to the fewest choices to smoke. Regulators should consider that the availability and characteristics of alternative tobacco products can moderate the product standard's impact. IMPLICATIONS: The U.S. Food and Drug Administration may enact a reduced nicotine product standard that would affect all commercially-available cigarettes. One important population affected by this policy would be early young adults who smoke. We aimed to determine the impact of cigarette nicotine content, vaping device nicotine concentration, and vaping device flavors on choices to smoke, vape, or abstain. Lower nicotine in cigarettes, along with non-tobacco flavors and lower nicotine concentration in the vaping device, were associated with the fewest choices to smoke. Regulators should consider that the availability and characteristics of alternative tobacco products can moderate the product standard's impact.
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Physical inactivity among older adults remains a global burden, leading to a variety of health challenges and even mortality. This study evaluated the impact of a novel virtual humanoid coach-driven physical exercise program among older adults. A non-randomized (quasi) experimental research was conducted in two community senior centers. The recruited participants (n = 130) were primarily female older adults with a mean age of 66.40 and agreed to be purposively assigned either experimental or control groups. Trained healthcare providers performed health assessments in three time points using valid and reliable tools. Descriptive statistics, t-tests, and RM-ANOVA were used to quantitatively analyze the data using SPSS version 22. There are significant mean differences between the groups across all functional capacity assessments and Time 2-3 assessment of sleep quality. RM-ANOVA revealed significant differences in physical assessment over time between the two groups. The analyses of time and group interaction revealed significant improvement in health assessments among the members of the mixed reality group compared to the traditional groups. The impact of virtual coaches in community-based enhancing physical activity programs is comparable to the traditional mode and introduces a novel approach to promoting physical activity among older adults.
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Exercício Físico , Humanos , Feminino , Idoso , Masculino , Filipinas , Pessoa de Meia-Idade , Realidade Virtual , Promoção da Saúde/métodosRESUMO
BACKGROUND: This study's purpose was to assess whether larger volumes of reinfused unwashed shed autologous blood (SAB) were associated with adverse events within 30 days for patients undergoing open thoracoabdominal aortic aneurysm (TAAA) repair. During TAAA repair, our institution uses a system wherein SAB is filtered, but not washed or centrifuged, and then returned to the patient via a rapid-infusion device. By reinfusing SAB, the system preserves the patient's autologous whole blood and may reduce the number of allogenic transfusions required during TAAA repair, but the end-organ effects of reinfusing unwashed SAB have not been extensively evaluated. METHODS: Using a prospectively maintained database, we retrospectively analyzed data from 972 consecutive patients who underwent open TAAA repair at our institution from 2007 to 2021 and who received SAB. Multivariable logistic regressions were performed to assess whether SAB reinfusion volume was associated with a composite outcome of adverse events, as well as operative mortality, a composite of cardiac complications, a composite of pulmonary complications, or persistent paraplegia, stroke, or postoperative renal failure. RESULTS: Among the cohort of 972 patients, the median volume of reinfused SAB was 4159 mL (quartile1-quartile3 [Q1-Q3]: 2524-6790 mL). Greater reinfusion volumes of unwashed SAB were not associated with greater odds of composite adverse events (odds ratio [OR], 1.02 per 1000 mL increase, 97.5% confidence interval [CI], 0.94-1.09, P = .624), nor with any individual outcome-operative mortality (OR, 1.02 per 1000 mL increase, 97.5% CI, 0.93-1.12, P = .617), a composite of cardiac complications (OR, 0.98 per 1000 mL increase, 97.5% CI, 0.93-1.04, P = .447), a composite of pulmonary complications (OR, 1.00 per 1000 mL increase, 97.5% CI, 0.94-1.06, P = .963), renal failure necessitating hemodialysis (OR, 1.01 per 1000 mL increase, 97.5% CI, 0.92-1.11, P = .821), persistent paraplegia (OR, 0.97 per 1000 mL increase, 97.5% CI, 0.84-1.13, P = .676), persistent stroke (OR, 0.85 per 1000 mL increase, 97.5% CI, 0.70-1.04, P = .070), or reoperation to control bleeding (OR, 0.99, 97.5% CI, 0.87-1.13, P = .900)-when adjusted for confounders. CONCLUSIONS: For patients undergoing open TAAA repair, larger reinfusion volumes of unwashed SAB were not associated with greater odds of major early postoperative complications.
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BACKGROUND: Margin accentuation using irreversible electroporation (MA-IRE) improves recurrence and overall survival (OS) in pancreatic cancer patients; however, there have been limited outcome comparisons to similarly risked patients who did not receive MA-IRE. METHODS: Patients with borderline resectable or locally advanced pancreatic adenocarcinoma who underwent a pancreaticoduodenectomy (PD) between 2017 and 2022 were included. Those who did not receive neoadjuvant chemotherapy for major vessel involvement were excluded. One-to-one propensity score matching (PSM) was used to match the MA-IRE group with the corresponding non-MA-IRE control group with similar risk factors. RESULTS: A total of 36 patients were included in this study. Seventeen (47.2%) patients who underwent MA-IRE matched with 19 control patients (52.8%) with similar risk factors who did not have MA-IRE. Before matching, OS and disease-free survival (DFS) were comparable between the MA-IRE and non-MA-IRE groups. After matching, the MA-IRE group showed improved OS (746 vs. 509 days, hazard ratio 0.313; p = 0.034) compared with the non-MA-IRE group. DFS (p = 0.768), negative margin status (p = 0.317), and 30-day complication rates (p = 1.000) remained statistically different between the groups. CONCLUSIONS: MA-IRE in PD results in longer OS but does not impact margin status, DFS, or postoperative complication rates in our cohort. These findings suggest that MA-IRE is safe and potentially promotes immune cell activation rather than upfront margin mitigation.
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AIM: There is concern that the provision of the clinical high risk for psychosis (CHR) label is stigmatizing. Prior research suggests people have nuanced reactions to feedback involving the CHR label, including a positive experience receiving feedback and improvement in negative emotions (e.g., shame), while also exhibiting concerns about self-perception and perceptions from others related to the label. The current pilot study aimed to evaluate whether individuals at CHR showed changes in emotional and stigma-related experiences following a CHR psychoeducation intervention, BEGIN: Brief Educational Guide for Individuals in Need. METHOD: Participants at CHR (N = 26) identified via the Structured Interview for Psychosis-Risk Syndromes completed the Mental Health Attitudes Interview measuring symptom-related and CHR label-related stigma at pre- and post-intervention. RESULTS: Stigma did not increase and participants had greater positive emotions (e.g., feeling hopeful and relieved), post-BEGIN. CONCLUSION: This study suggests that standardized CHR psychoeducation does not increase stigma in individuals at CHR.
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Chlorine oxides play crucial roles in ozone depletion, and the final oxidation steps of chlorine oxide potentially result in the formation of chloric acid (HClO3) or perchloric acid (HClO4). Herein, the solvation and reactive uptake of three stable isomers of chlorine trioxide (Cl2O3), namely, ClOCl(O)O, ClClO3, and ClOOOCl, at the air-water interface were investigated using classical and hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) coupled with advanced free energy methods. Two distinct mechanisms were revealed for the hydrolysis of ClOCl(O)O and ClClO3: molecular and ionic mechanisms. A comparison of the computed free-energy profiles for the gaseous and air-water interfacial systems indicated that the air-water interface could markedly lower the free-energy barrier for ClO3- or HClO3 formation while stabilizing the product state. In particular, the hydrolysis of ClClO3 at the air-water interface was barrierless. In contrast, our calculations showed that the hydrolysis of ClOOOCl was very slow, indicating that ClOOOCl was inert to water at the air-water interface. This study provides theoretical evidence for the hypothesis that HClO3 is a sink for chlorine oxides and for the widespread distributions of HClO3 recently observed in the Arctic region.
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BACKGROUND: Synaptic Ras GTPase activating protein 1 (SYNGAP1)-related non-specific intellectual disability is a neurodevelopmental disorder caused by an insufficient level of SynGAP1 resulting in a dysfunction of neuronal synapses and presenting with a wide array of clinical phenotypes. Hematopoietic stem cell gene therapy has the potential to deliver therapeutic levels of functional SynGAP1 to affected neurons upon transduction of hematopoietic stem and progenitor cells with a lentiviral vector. METHODS: As a novel approach toward the treatment of SYNGAP1, we have generated a lentiviral vector expressing a modified form of SynGAP1 for transduction of human CD34+ hematopoietic stem and progenitor cells. The gene-modified cells were then transplanted into adult immunodeficient SYNGAP1+/- heterozygous mice and evaluated for improvement of SYNGAP1-related clinical phenotypes. Expression of SynGAP1 was also evaluated in the brain tissue of transplanted mice. RESULTS: In our proof-of-concept study, we have demonstrated significant improvement of SYNGAP1-related phenotypes including an improvement in motor abilities observed in mice transplanted with the vector transduced cells because they displayed decreased hyperactivity in an open field assay and an increased latency to fall in a rotarod assay. An increased level of SynGAP1 was also detected in the brains of these mice. CONCLUSIONS: These early-stage results highlight the potential of this stem cell gene therapy approach as a treatment strategy for SYNGAP1.
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Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Deficiência Intelectual , Animais , Humanos , Camundongos , Encéfalo/metabolismo , Modelos Animais de Doenças , Terapia Genética/métodos , Vetores Genéticos/genética , Células-Tronco Hematopoéticas/metabolismo , Deficiência Intelectual/terapia , Deficiência Intelectual/genética , Lentivirus/genética , Proteínas Ativadoras de ras GTPase/genética , Proteínas Ativadoras de ras GTPase/metabolismo , Transdução GenéticaRESUMO
Idiopathic pulmonary fibrosis (IPF) is an age-related disease with poor prognosis and limited therapeutic options. Activation of lung fibroblasts and differentiation to myofibroblasts are the principal effectors of disease pathology, but damage and senescence of alveolar epithelial cells, specifically type II (ATII) cells, has recently been identified as a potential trigger event for the progressive disease cycle. Targeting ATII senescence and the senescence-associated secretory phenotype (SASP) is an attractive therapeutic strategy; however, translatable primary human cell models that enable mechanistic studies and drug development are lacking. Here, we describe a novel system of conditioned medium (CM) transfer from bleomycin-induced senescent primary alveolar epithelial cells (AEC) onto normal human lung fibroblasts (NHLF) that demonstrates an enhanced fibrotic transcriptional and secretory phenotype compared to non-senescent AEC CM treatment or direct bleomycin damage of the NHLFs. In this system, the bleomycin-treated AECs exhibit classical hallmarks of cellular senescence, including SASP and a gene expression profile that resembles aberrant epithelial cells of the IPF lung. Fibroblast activation by CM transfer is attenuated by pre-treatment of senescent AECs with the senolytic Navitoclax and AD80, but not with the standard of care agent Nintedanib or senomorphic JAK-targeting drugs (e.g., ABT-317, ruxolitinib). This model provides a relevant human system for profiling novel senescence-targeting therapeutics for IPF drug development.
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Células Epiteliais Alveolares , Bleomicina , Senescência Celular , Fibroblastos , Fibrose Pulmonar Idiopática , Humanos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Bleomicina/toxicidade , Bleomicina/farmacologia , Senescência Celular/efeitos dos fármacos , Células Epiteliais Alveolares/efeitos dos fármacos , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Fibrose Pulmonar Idiopática/patologia , Fibrose Pulmonar Idiopática/metabolismo , Meios de Cultivo Condicionados/farmacologia , Indóis/farmacologia , Fenótipo Secretor Associado à Senescência/efeitos dos fármacos , Pulmão/patologia , Pulmão/citologia , Pulmão/efeitos dos fármacos , Sulfonamidas/farmacologia , Senoterapia/farmacologia , Células Cultivadas , Pirimidinas/farmacologia , Pirazóis/farmacologia , Nitrilas/farmacologia , Compostos de AnilinaRESUMO
The severity of bacterial pneumonia can be worsened by impaired innate immunity resulting in ineffective pathogen clearance. We describe a mitochondrial protein, aspartyl-tRNA synthetase (DARS2), which is released in circulation during bacterial pneumonia in humans and displays intrinsic innate immune properties and cellular repair properties. DARS2 interacts with a bacterial-induced ubiquitin E3 ligase subunit, FBXO24, which targets the synthetase for ubiquitylation and degradation, a process that is inhibited by DARS2 acetylation. During experimental pneumonia, Fbxo24 knockout mice exhibit elevated DARS2 levels with an increase in pulmonary cellular and cytokine levels. In silico modeling identified an FBXO24 inhibitory compound with immunostimulatory properties which extended DARS2 lifespan in cells. Here, we show a unique biological role for an extracellular, mitochondrially derived enzyme and its molecular control by the ubiquitin apparatus, which may serve as a mechanistic platform to enhance protective host immunity through small molecule discovery.
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Aspartato-tRNA Ligase , Imunidade Inata , Camundongos Knockout , Mitocôndrias , Ubiquitinação , Animais , Aspartato-tRNA Ligase/metabolismo , Aspartato-tRNA Ligase/genética , Humanos , Camundongos , Mitocôndrias/metabolismo , Proteínas F-Box/metabolismo , Proteínas F-Box/genética , Camundongos Endogâmicos C57BL , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Proteólise , Feminino , Masculino , Citocinas/metabolismo , Células HEK293 , Acetilação , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genéticaRESUMO
The photochemistry of nitrous acid (HONO), encompassing dissociation into OH and NO as well as the reverse association reaction, plays a pivotal role in atmospheric chemistry. Here, we report the direct observation of nitrosyl-O-hydroxide (HOON) in the photochemistry of HONO, employing matrix-isolation IR and UV-vis spectroscopy. Despite a barrier of approximately 30 kJ/mol, HOON undergoes spontaneous rearrangement to the more stable HONO isomer through quantum mechanical tunneling, with a half-life of 28 min at 4 K. Kinetic isotope effects and instanton theory calculations reveal that the tunneling process involves the concerted motion of the NO moiety (65.2%) and the hydrogen atom (32.3%). Our findings underscore the significance of HOON as a key intermediate in the photolytic dissociation-association cycle of HONO at low temperatures.