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Mitochondria fulfill a diverse range of functions in cells including oxygen metabolism, homeostasis of inorganic ions and execution of apoptosis. Biogenesis of mitochondria relies on protein import pathways that are ensured by dedicated multiprotein translocase complexes localized in all sub-compartments of these organelles. The key components and pathways involved in protein targeting and assembly have been characterized in great detail over the last three decades. This includes the oxidative folding machinery in the intermembrane space, which contributes to the redox-dependent control of proteostasis. Here, we focus on several components of this system and discuss recent evidence suggesting links to human proteopathy.
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Enfermedad , Membranas Mitocondriales/metabolismo , Proteínas Mitocondriales/metabolismo , Humanos , Pliegue de Proteína , Mapeo de Interacción de Proteínas , Transporte de ProteínasRESUMEN
Mitochondria are organelles that play a central role in cellular metabolism, as they are responsible for processes such as iron/sulfur cluster biogenesis, respiration and apoptosis. Here, we describe briefly the various protein import pathways for sorting of mitochondrial proteins into the different subcompartments, with an emphasis on the targeting to the intermembrane space. The discovery of a dedicated redox-controlled pathway in the intermembrane space that links protein import to oxidative protein folding raises important questions on the redox regulation of this process. We discuss the salient features of redox regulation in the intermembrane space and how such mechanisms may be linked to the more general redox homeostasis balance that is crucial not only for normal cell physiology but also for cellular dysfunction.
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Membranas Mitocondriales/metabolismo , Proteínas Mitocondriales/metabolismo , Biosíntesis de Proteínas , Disulfuros/metabolismo , Humanos , Oxidación-Reducción , Transporte de ProteínasRESUMEN
INTRODUCTION: Treatment with monoclonal antibodies provides rapid, passive immunity and may stop COVID-19 disease progression. The study evaluated the effect of bamlanivimab (BAM) or BAM + etesevimab (ETE)/sotrovimab compared to placebo on SARS-CoV-2 viral load in patients with COVID-19. METHODS: The phase 2, randomized, single-dose study included patients aged between ≥ 18 and < 65 years, not hospitalized at the time of randomization, and had ≥ 1 mild or moderate COVID-19 symptoms. Study included arms 1-6 (placebo, BAM 175 mg + ETE 350 mg, BAM 700 mg + ETE 1400 mg, BAM 2800 mg + ETE 2800 mg, BAM 700 mg alone, and BAM 350 mg + ETE 700 mg, respectively), BAM 700 mg + ETE 700 mg unintentional dosing; and arms 7 and 8 (BAM 700 mg + sotrovimab 500 mg and placebo, respectively). The primary endpoint was proportion of patients with SARS-CoV-2 log viral load > 5.27 on day 7 (persistently high viral load [PHVL]) who received BAM or BAM + (ETE or sotrovimab). RESULTS: A total of 725 patients, mean age 39.6 years (range 18-75 years), 50.2% male were randomized and infused with study drug in arms 1-6; and a total 202 patients, mean age 38 years (range 18-63 years), 53.5% female were randomized and infused with study drug in arms 7 and 8. A significantly lower proportion of patients in arms 2-6 and arm 7 experienced PHVL on day 7 compared to placebo. On day 7, patients in arms 2, 3, and 6 consistently experienced significantly greater reduction in viral load than placebo. Significant improvement was observed in time to viral load clearance and time to symptom improvement by day 29 in some arms compared to placebo. No new safety concerns were observed with drug combinations. CONCLUSION: The study demonstrated that a significantly lower proportion of patients with mild-to-moderate COVID-19 treated with BAM or BAM + (ETE or sotrovimab) experienced a PHVL at day 7. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT04634409.
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INTRODUCTION: Bamlanivimab and etesevimab (BAM + ETE) are monoclonal antibodies (mAbs) effective in reducing COVID-19-related hospitalizations and all-cause mortality in adult participants at increased risk for severe disease. We present pharmacokinetic (PK), efficacy, and safety results from pediatric participants (< 18 years of age) with COVID-19 who were treated with BAM + ETE. METHODS: In an addendum to the phase 2/3 BLAZE-1 clinical trial (NCT04427501), pediatric participants received open-label weight-based dosing (WBD, n = 94) based on exposure-matching to the authorized dose of BAM + ETE in adult participants. For efficacy and safety assessments, placebo (n = 14) and BAM + ETE (n = 20)-treated adolescent participants (> 12 to < 18 years of age) from the BLAZE-1 trial were included in the overall pediatric population (N = 128). All participants had mild to moderate COVID-19 upon enrollment and ≥ 1 risk factor for severe COVID-19. The primary objective was to characterize the PK of BAM and ETE in the WBD population. RESULTS: The median age of the participants was 11.2 years, 46.1% were female, 57.9% were Black/African American, and 19.7% were Hispanic/Latino. The area under the curve for BAM and ETE in the WBD population was similar to that previously observed in adults. There were no COVID-19-related hospitalizations or deaths. All adverse events (AE) except one were mild or moderate, with one participant reporting a serious AE. CONCLUSION: WBD in pediatric participants achieved similar drug exposures compared to adult participants that received the authorized BAM + ETE dose. The pediatric efficacy and safety data were consistent with adults receiving mAbs for COVID-19. TRIAL REGISTRATION NUMBER: NCT04427501.
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BACKGROUND/OBJECTIVE: The aim of this study was to evaluate relative performance of composite measures in psoriatic arthritis and assess the impact of structural damage and functional disability on outcomes during ixekizumab treatment. METHODS: Data from SPIRIT-P1 and SPIRIT-P2 were analysed to evaluate the effect of ixekizumab on achievement of low disease activity (LDA) and remission with the minimal disease activity (MDA) and very low disease activity (VLDA) composite, Disease Activity index for Psoriatic Arthritis (DAPSA), Psoriatic Arthritis Disease Activity Score, GRAppa Composite ScorE and modified Composite Psoriatic Disease Activity Index (mCPDAI). Performance was compared by quantifying residual symptom burden and the impact of structural damage and functional disability. RESULTS: Significantly more ixekizumab-treated patients achieved treatment targets at week 24 versus placebo assessed with all composites. More patients achieved targets assessed by mCPDAI and DAPSA than other composites. Residual disease activity was similar between composites, but residual high patient-reported outcomes (PROs) and functional disability were more frequent when assessed with mCPDAI and DAPSA. Achievement of treatment targets was reduced by high baseline levels of structural damage and functional disability. CONCLUSION: Residual disease activity was similar in patients achieving treatment targets assessed with all composites, but residual high PROs and functional disability were more common when assessed with mCPDAI and DAPSA, most likely due to the absence/attenuated functional assessment in these composites. High baseline levels of structural damage and functional disability attenuated response rates with all composites, affecting MDA/VLDA most prominently; LDA may be the most appropriate target in these patients. TRIAL REGISTRATION NUMBER: NCT01695239.
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Antirreumáticos , Artritis Psoriásica , Anticuerpos Monoclonales Humanizados , Antirreumáticos/uso terapéutico , Artritis Psoriásica/diagnóstico , Artritis Psoriásica/tratamiento farmacológico , Progresión de la Enfermedad , Humanos , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Background: In the phase 2/3 BLAZE-1 trial, bamlanivimab and etesevimab together reduced coronavirus disease 2019 (COVID-19)-related hospitalizations and any-cause mortality in ambulatory patients. Herein, we assess the impact of bamlanivimab and etesevimab treatment on the severity and length of symptoms and health outcomes among patients at increased risk for severe COVID-19. Methods: In the phase 3 portion of BLAZE-1 (NCT04427501), symptomatic patients with increased risk for severe COVID-19 were randomized (2:1) to a single infusion of 700 mg bamlanivimab and 1400 mg etesevimab or placebo. Hospitalization events, vital signs, and symptomatology were monitored throughout the trial. Results: Overall, 769 patients were randomized to bamlanivimab and etesevimab together (nâ =â 511) or placebo (nâ =â 258). The time to sustained symptom resolution was significantly shorter among patients who received bamlanivimab and etesevimab compared with placebo (8 vs 10 days; Pâ <â .01). The median time to first sustained symptom resolution of body aches and pain, chills, fatigue, feeling feverish, headache, and shortness of breath was significantly different in patients receiving bamlanivimab and etesevimab compared to placebo (Pâ <â .05). The proportion of patients who experienced COVID-19-related hospitalization by day 29 was significantly reduced among the bamlanivimab and etesevimab group compared with placebo (0.8% vs 5.4%; Pâ <â .01). The mean duration of hospital stay was numerically shorter among patients who received bamlanivimab and etesevimab (7.3 vs 13.5 days; Pâ =â .16), with fewer intensive care admissions. Conclusions: Patients receiving bamlanivimab and etesevimab together resolved their symptoms more rapidly than those receiving placebo. Bamlanivimab and etesevimab treatment was associated with reduced rates of hospitalizations and shorter hospital stays. Clinical Trials Registration: NCT04427501.
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PURPOSE: Ixekizumab is a high-affinity monoclonal antibody that selectively targets interleukin-17A. The objective of this study was to assess the long-term efficacy and safety (to week 156) of ixekizumab in patients with active psoriatic arthritis and inadequate response or intolerance to one or two tumor necrosis factor inhibitors. METHODS: In the SPIRIT-P2 study (ClinicalTrials.gov ID: NCT02349295), patients were randomized to placebo or ixekizumab 80 mg every 4 weeks (IXE Q4W) or every 2 weeks (IXE Q2W) following a 160-mg starting dose. During the extension period (weeks 24-156), patients maintained their original ixekizumab dose, and placebo patients received IXE Q4W or IXE Q2W (1:1). Exposure-adjusted incidence rates (IRs) per 100 patient-years (PY) are presented. RESULTS: Of 363 patients enrolled in the study, 310 entered the extension period. In all patients treated with IXE Q4W and IXE Q2W at week 0, responses persisted to week 156. At week 156, clinical responses (observed) in patients treated with IXE Q4W and IXE Q2W were assessed [American College of Rheumatology (ACR) response criteria and minimal disease activity (MDA) criteria]: 84 and 85% showed 20% improvement (ACR20); 60 and 58% showed 50% improvement (ACR50); 35 and 47% showed 70% improvement (ACR70), respectively; and 48 and 54% showed MDA. Placebo patients re-randomized to ixekizumab also demonstrated sustained efficacy, as measured by ACR and MDA responses. In the All Ixekizumab Exposure Safety Population (n = 337), with 644 PY of ixekizumab exposure, treatment-emergent adverse events (TEAEs) were reported by 286 patients (44.4 IR). The most common TEAEs were upper respiratory tract infection (9.80 IR), nasopharyngitis (8.2 IR), sinusitis (6.2 IR), and bronchitis (4.5 IR). Serious adverse events were reported by 42 (6.5 IR) patients (included 3 deaths and 10 infections). CONCLUSION: In this 156-week study of ixekizumab, improvements in signs and symptoms of psoriatic arthritis and the safety profile remained consistent with those in previous reports. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02349295.