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1.
Hepatology ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38954820

RESUMO

Alpha-1 antitrypsin deficiency (A1ATD) is a life-threatening condition caused by inheritance of the SERPINA1 'Z' genetic variant (PiZ) driving AAT protein misfolding in hepatocytes. There remain no approved medicines for this disease. Here, we report the results of a small molecule screen performed in patient derived iPSC-hepatocytes that identified Leucine-rich repeat kinase-2 (LRRK2) as a potentially new therapeutic target. Of the commercially available LRRK2 inhibitors tested, we identified CZC-25146, a candidate with favorable pharmacokinetic properties, as being capable of reducing polymer load, increasing normal AAT secretion, and reducing inflammatory cytokines in both cells and PiZ mice. Mechanistically, this effect was achieved through induction of autophagy. Our findings support the use of CZC-25146 and LRRK2 inhibitors in hepatic proteinopathy research and their further investigation as novel therapeutic candidates for A1ATD.

2.
FEBS J ; 291(13): 2937-2954, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38523412

RESUMO

Mutants of alpha-1-antitrypsin cause the protein to self-associate and form ordered aggregates ('polymers') that are retained within hepatocytes, resulting in a predisposition to the development of liver disease. The associated reduction in secretion, and for some mutants, impairment of function, leads to a failure to protect lung tissue against proteases released during the inflammatory response and an increased risk of emphysema. We report here a novel deficiency mutation (Gly192Cys), that we name the Sydney variant, identified in a patient in heterozygosity with the Z allele (Glu342Lys). Cellular analysis revealed that the novel variant was mostly retained as insoluble polymers within the endoplasmic reticulum. The basis for this behaviour was investigated using biophysical and structural techniques. The variant showed a 40% reduction in inhibitory activity and a reduced stability as assessed by thermal unfolding experiments. Polymerisation involves adoption of an aggregation-prone intermediate and paradoxically the energy barrier for transition to this state was increased by 16% for the Gly192Cys variant with respect to the wild-type protein. However, with activation to the intermediate state, polymerisation occurred at a 3.8-fold faster rate overall. X-ray crystallography provided two crystal structures of the Gly192Cys variant, revealing perturbation within the 'breach' region with Cys192 in two different orientations: in one structure it faces towards the hydrophobic core while in the second it is solvent-exposed. This orientational heterogeneity was confirmed by PEGylation. These data show the critical role of the torsional freedom imparted by Gly192 in inhibitory activity and stability against polymerisation.


Assuntos
alfa 1-Antitripsina , Humanos , alfa 1-Antitripsina/genética , alfa 1-Antitripsina/química , alfa 1-Antitripsina/metabolismo , Cristalografia por Raios X , Mutação , Modelos Moleculares , Agregados Proteicos , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Agregação Patológica de Proteínas/patologia , Conformação Proteica , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/genética
3.
Methods Mol Biol ; 2750: 41-55, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38108966

RESUMO

In this chapter, we describe a method for analyzing both recombinant and plasma-derived alpha 1 antitrypsin and its oligomers by means of native ion mobility mass spectrometry. Our experimental workflow can be applied to other variants of alpha 1 antitrypsin and its oligomers as well as being used to probe their interactions with small molecules in the gas phase.


Assuntos
Espectrometria de Mobilidade Iônica , alfa 1-Antitripsina , alfa 1-Antitripsina/genética , Plasma , Fluxo de Trabalho , Espectrometria de Massas
4.
EMBO Mol Med ; 15(6): e17144, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-37158379

RESUMO

In the practice of medicine, many fundamental biological pathways that require tight on/off control, such as inflammation and circulatory homeostasis, are regulated by serine proteinases, but we rarely consider the unique protease inhibitors that, in turn, regulate these proteases. The serpins are a family of proteins with a shared tertiary structure, whose members largely act as serine protease inhibitors, found in all forms of life, ranging from viruses, bacteria, and archaea to plants and animals. These proteins represent up to 2-10% of proteins in the human blood and are the third most common protein family.


Assuntos
Serpinas , Animais , Humanos , Serpinas/genética , Serpinas/química , Serpinas/metabolismo , Inibidores de Serina Proteinase/farmacologia , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/metabolismo , Serina Proteases/metabolismo , Inflamação
5.
Respir Res ; 24(1): 38, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726148

RESUMO

BACKGROUND: The association between genetic variants on the X chromosome to risk of COPD has not been fully explored. We hypothesize that the X chromosome harbors variants important in determining risk of COPD related phenotypes and may drive sex differences in COPD manifestations. METHODS: Using X chromosome data from three COPD-enriched cohorts of adult smokers, we performed X chromosome specific quality control, imputation, and testing for association with COPD case-control status, lung function, and quantitative emphysema. Analyses were performed among all subjects, then stratified by sex, and subsequently combined in meta-analyses. RESULTS: Among 10,193 subjects of non-Hispanic white or European ancestry, a variant near TMSB4X, rs5979771, reached genome-wide significance for association with lung function measured by FEV1/FVC ([Formula: see text] 0.020, SE 0.004, p 4.97 × 10-08), with suggestive evidence of association with FEV1 ([Formula: see text] 0.092, SE 0.018, p 3.40 × 10-07). Sex-stratified analyses revealed X chromosome variants that were differentially trending in one sex, with significantly different effect sizes or directions. CONCLUSIONS: This investigation identified loci influencing lung function, COPD, and emphysema in a comprehensive genetic association meta-analysis of X chromosome genetic markers from multiple COPD-related datasets. Sex differences play an important role in the pathobiology of complex lung disease, including X chromosome variants that demonstrate differential effects by sex and variants that may be relevant through escape from X chromosome inactivation. Comprehensive interrogation of the X chromosome to better understand genetic control of COPD and lung function is important to further understanding of disease pathology. Trial registration Genetic Epidemiology of COPD Study (COPDGene) is registered at ClinicalTrials.gov, NCT00608764 (Active since January 28, 2008). Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints Study (ECLIPSE), GlaxoSmithKline study code SCO104960, is registered at ClinicalTrials.gov, NCT00292552 (Active since February 16, 2006). Genetics of COPD in Norway Study (GenKOLS) holds GlaxoSmithKline study code RES11080, Genetics of Chronic Obstructive Lung Disease.


Assuntos
Enfisema , Doença Pulmonar Obstrutiva Crônica , Enfisema Pulmonar , Feminino , Masculino , Humanos , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/genética , Fenótipo , Cromossomo X
6.
Cell Mol Life Sci ; 79(9): 503, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36045259

RESUMO

Early recognition and enhanced degradation of misfolded proteins by the endoplasmic reticulum (ER) quality control and ER-associated degradation (ERAD) cause defective protein secretion and membrane targeting, as exemplified for Z-alpha-1-antitrypsin (Z-A1AT), responsible for alpha-1-antitrypsin deficiency (A1ATD) and F508del-CFTR (cystic fibrosis transmembrane conductance regulator) responsible for cystic fibrosis (CF). Prompted by our previous observation that decreasing Keratin 8 (K8) expression increased trafficking of F508del-CFTR to the plasma membrane, we investigated whether K8 impacts trafficking of soluble misfolded Z-A1AT protein. The subsequent goal of this study was to elucidate the mechanism underlying the K8-dependent regulation of protein trafficking, focusing on the ERAD pathway. The results show that diminishing K8 concentration in HeLa cells enhances secretion of both Z-A1AT and wild-type (WT) A1AT with a 13-fold and fourfold increase, respectively. K8 down-regulation triggers ER failure and cellular apoptosis when ER stress is jointly elicited by conditional expression of the µs heavy chains, as previously shown for Hrd1 knock-out. Simultaneous K8 silencing and Hrd1 knock-out did not show any synergistic effect, consistent with K8 acting in the Hrd1-governed ERAD step. Fractionation and co-immunoprecipitation experiments reveal that K8 is recruited to ERAD complexes containing Derlin2, Sel1 and Hrd1 proteins upon expression of Z/WT-A1AT and F508del-CFTR. Treatment of the cells with c407, a small molecule inhibiting K8 interaction, decreases K8 and Derlin2 recruitment to high-order ERAD complexes. This was associated with increased Z-A1AT secretion in both HeLa and Z-homozygous A1ATD patients' respiratory cells. Overall, we provide evidence that K8 acts as an ERAD modulator. It may play a scaffolding protein role for early-stage ERAD complexes, regulating Hrd1-governed retrotranslocation initiation/ubiquitination processes. Targeting K8-containing ERAD complexes is an attractive strategy for the pharmacotherapy of A1ATD.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Degradação Associada com o Retículo Endoplasmático , Queratina-8/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Células HeLa , Humanos , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
7.
BMC Med Educ ; 22(1): 17, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983477

RESUMO

BACKGROUND: Despite considerable efforts there continues to be a degree awarding gap within the United Kingdom (UK) between the proportion of White British students receiving higher classifications, compared to ethnic minority UK-domiciled students. Practice placement elements constitute approximately 50% of most health and social care programmes, yet surprisingly little research exists related to the factors which may contribute to ethnic minority student placement outcomes or experiences. This study bridges this evidence gap by exploring factors influencing differential placement outcomes of ethnic minority students from the perspectives of key stakeholders. METHODS: The study followed a descriptive qualitative research design and was multi-disciplinary, with participants drawn from across nursing, midwifery, social work and the allied health professions. Participants from four stakeholder categories (ethnic minority students, academic staff, placement educators and student union advisors) were invited to join separate focus groups. Focus groups were recorded and transcribed and analysed thematically. RESULTS: Ten separate focus groups [n = 66] yielded three primary themes: 1) recognition, which highlighted stakeholder perceptions of the issues [sub-themes: acknowledging concerns; cultural norms; challenging environments]; 2) the lived experience, which primarily captured ethnic minority student perspectives [sub-themes: problematising language and stereotyping, and being treated differently]; 3) surviving not thriving, which outlines the consequences of the lived experience [sub-themes: withdrawing mentally, feeling like an alien]. CONCLUSION: This study presents a rich exploration of the factors affecting differential outcomes of ethnic minority students on practice placements through the lens of four different stakeholder groups. To our knowledge this is the first study in which this comprehensive approach has been taken to enable multiple viewpoints to be accessed across a wide range of health and social care professions. The issues and challenges raised appear to be common to most if not all of these disciplines. This study highlights the urgent need to value and support our ethnic minority students to remove the barriers they face in their practice learning settings. This is a monumental challenge and requires both individuals and organisations to step up and take collective responsibility.


Assuntos
Minorias Étnicas e Raciais , Etnicidade , Humanos , Grupos Minoritários , Pesquisa Qualitativa , Apoio Social , Estudantes
9.
Gut ; 71(2): 415-423, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33632708

RESUMO

OBJECTIVE: Alpha-1 antitrypsin deficiency (AATD) is a common, potentially lethal inborn disorder caused by mutations in alpha-1 antitrypsin (AAT). Homozygosity for the 'Pi*Z' variant of AAT (Pi*ZZ genotype) causes lung and liver disease, whereas heterozygous 'Pi*Z' carriage (Pi*MZ genotype) predisposes to gallstones and liver fibrosis. The clinical significance of the more common 'Pi*S' variant remains largely undefined and no robust data exist on the prevalence of liver tumours in AATD. DESIGN: Baseline phenotypes of AATD individuals and non-carriers were analysed in 482 380 participants in the UK Biobank. 1104 participants of a multinational cohort (586 Pi*ZZ, 239 Pi*SZ, 279 non-carriers) underwent a comprehensive clinical assessment. Associations were adjusted for age, sex, body mass index, diabetes and alcohol consumption. RESULTS: Among UK Biobank participants, Pi*ZZ individuals displayed the highest liver enzyme values, the highest occurrence of liver fibrosis/cirrhosis (adjusted OR (aOR)=21.7 (8.8-53.7)) and primary liver cancer (aOR=44.5 (10.8-183.6)). Subjects with Pi*MZ genotype had slightly elevated liver enzymes and moderately increased odds for liver fibrosis/cirrhosis (aOR=1.7 (1.2-2.2)) and cholelithiasis (aOR=1.3 (1.2-1.4)). Individuals with homozygous Pi*S mutation (Pi*SS genotype) harboured minimally elevated alanine aminotransferase values, but no other hepatobiliary abnormalities. Pi*SZ participants displayed higher liver enzymes, more frequent liver fibrosis/cirrhosis (aOR=3.1 (1.1-8.2)) and primary liver cancer (aOR=6.6 (1.6-26.9)). The higher fibrosis burden was confirmed in a multinational cohort. Male sex, age ≥50 years, obesity and the presence of diabetes were associated with significant liver fibrosis. CONCLUSION: Our study defines the hepatobiliary phenotype of individuals with the most relevant AATD genotypes including their predisposition to liver tumours, thereby allowing evidence-based advice and individualised hepatological surveillance.


Assuntos
Colelitíase/epidemiologia , Cirrose Hepática/epidemiologia , Neoplasias Hepáticas/epidemiologia , Deficiência de alfa 1-Antitripsina/complicações , Adulto , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prevalência , Reino Unido
10.
Am J Respir Crit Care Med ; 205(3): 313-323, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34762809

RESUMO

Rationale: Multiple studies have demonstrated an increased risk of chronic obstructive pulmonary disease (COPD) in heterozygous carriers of the AAT (alpha-1 antitrypsin) Z allele. However, it is not known if MZ subjects with COPD are phenotypically different from noncarriers (MM genotype) with COPD. Objectives: To assess if MZ subjects with COPD have different clinical features compared with MM subjects with COPD. Methods: Genotypes of SERPINA1 were ascertained by using whole-genome sequencing data in three independent studies. We compared outcomes between MM subjects with COPD and MZ subjects with COPD in each study and combined the results in a meta-analysis. We performed longitudinal and survival analyses to compare outcomes in MM and MZ subjects with COPD over time. Measurements and Main Results: We included 290 MZ subjects with COPD and 6,184 MM subjects with COPD across the three studies. MZ subjects had a lower FEV1% predicted and greater quantitative emphysema on chest computed tomography scans compared with MM subjects. In a meta-analysis, the FEV1 was 3.9% lower (95% confidence interval [CI], -6.55% to -1.26%) and emphysema (the percentage of lung attenuation areas <-950 HU) was 4.14% greater (95% CI, 1.44% to 6.84%) in MZ subjects. We found one gene, PGF (placental growth factor), to be differentially expressed in lung tissue from one study between MZ subjects and MM subjects. Conclusions: Carriers of the AAT Z allele (those who were MZ heterozygous) with COPD had lower lung function and more emphysema than MM subjects with COPD. Taken with the subtle differences in gene expression between the two groups, our findings suggest that MZ subjects represent an endotype of COPD.


Assuntos
Genótipo , Heterozigoto , Fenótipo , Doença Pulmonar Obstrutiva Crônica/genética , alfa 1-Antitripsina/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Marcadores Genéticos , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/mortalidade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Testes de Função Respiratória , Análise de Sobrevida , Sequenciamento Completo do Genoma
11.
ERJ Open Res ; 7(3)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34476245

RESUMO

RATIONALE: COPD and smoking are characterised by pulmonary inflammation. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging may improve knowledge of pulmonary inflammation in COPD patients and aid early development of novel therapies as an imaging biomarker. OBJECTIVES: To evaluate pulmonary inflammation, assessed by FDG uptake, in whole and regional lung in "usual" (smoking-related) COPD patients, alpha-1 antitrypsin deficiency (α1ATD) COPD patients, smokers without COPD and never-smokers using FDG PET/CT. Secondly, to explore cross-sectional associations between FDG PET/CT and systemic inflammatory markers in COPD patients and repeatability of the technique in COPD patients. METHODS: Data from two imaging studies were evaluated. Pulmonary FDG uptake (normalised Ki; nKi) was measured by Patlak graphical analysis in four subject groups: 84 COPD patients, 11 α1ATD-COPD patients, 12 smokers and 10 never-smokers. Within the COPD group, associations between nKi and systemic markers of inflammation were assessed. Repeatability was evaluated in 32 COPD patients comparing nKi values at baseline and at 4-month follow-up. RESULTS: COPD patients, α1ATD-COPD patients and smokers had increased whole lung FDG uptake (nKi) compared with never-smokers (0.0037±0.001, 0.0040±0.001, 0.0040±0.001 versus 0.0028±0.001 mL·cm-3·min-1, respectively, p<0.05 for all). Similar results were observed in upper and middle lung regions. In COPD participants, plasma fibrinogen was associated with whole lung nKi (ß=0.30, p=0.02) in multivariate analysis adjusted for current smoking, forced expiratory volume in 1 s % predicted, systemic neutrophils and C-reactive protein levels. Mean percentage difference in nKi between the baseline and follow-up was 3.2%, and the within subject coefficient of variability was 7.7%. CONCLUSIONS: FDG PET/CT has potential as a noninvasive tool to enable whole lung and regional quantification of FDG uptake to assess smoking- and COPD-related pulmonary inflammation.

12.
J Cachexia Sarcopenia Muscle ; 12(6): 1803-1817, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34523824

RESUMO

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally. COPD patients with cachexia or weight loss have increased risk of death independent of body mass index (BMI) and lung function. We tested the hypothesis genetic variation is associated with weight loss in COPD using a genome-wide association study approach. METHODS: Participants with COPD (N = 4308) from three studies (COPDGene, ECLIPSE, and SPIROMICS) were analysed. Discovery analyses were performed in COPDGene with replication in SPIROMICS and ECLIPSE. In COPDGene, weight loss was defined as self-reported unintentional weight loss > 5% in the past year or low BMI (BMI < 20 kg/m2 ). In ECLIPSE and SPIROMICS, weight loss was calculated using available longitudinal visits. Stratified analyses were performed among African American (AA) and Non-Hispanic White (NHW) participants with COPD. Single variant and gene-based analyses were performed adjusting for confounders. Fine mapping was performed using a Bayesian approach integrating genetic association results with linkage disequilibrium and functional annotation. Significant gene networks were identified by integrating genetic regions associated with weight loss with skeletal muscle protein-protein interaction (PPI) data. RESULTS: At the single variant level, only the rs35368512 variant, intergenic to GRXCR1 and LINC02383, was associated with weight loss (odds ratio = 3.6, 95% confidence interval = 2.3-5.6, P = 3.2 × 10-8 ) among AA COPD participants in COPDGene. At the gene level in COPDGene, EFNA2 and BAIAP2 were significantly associated with weight loss in AA and NHW COPD participants, respectively. The EFNA2 association replicated among AA from SPIROMICS (P = 0.0014), whereas the BAIAP2 association replicated in NHW from ECLIPSE (P = 0.025). The EFNA2 gene encodes the membrane-bound protein ephrin-A2 involved in the regulation of developmental processes and adult tissue homeostasis such as skeletal muscle. The BAIAP2 gene encodes the insulin-responsive protein of mass 53 kD (IRSp53), a negative regulator of myogenic differentiation. Integration of the gene-based findings participants with PPI data revealed networks of genes involved in pathways such as Rho and synapse signalling. CONCLUSIONS: The EFNA2 and BAIAP2 genes were significantly associated with weight loss in COPD participants. Collectively, the integrative network analyses indicated genetic variation associated with weight loss in COPD may influence skeletal muscle regeneration and tissue remodelling.


Assuntos
Estudo de Associação Genômica Ampla , Doença Pulmonar Obstrutiva Crônica , Adulto , Teorema de Bayes , Variação Genética , Humanos , Músculo Esquelético , Proteínas do Tecido Nervoso , Doença Pulmonar Obstrutiva Crônica/genética , Regeneração , Redução de Peso/genética
15.
Int J Mol Sci ; 22(11)2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073489

RESUMO

Alpha-1-antitrypsin (AAT) deficiency causes pulmonary disease due to decreased levels of circulating AAT and consequently unbalanced protease activity in the lungs. Deposition of specific AAT variants, such as the common Z AAT, within hepatocytes may also result in liver disease. These deposits are comprised of ordered polymers of AAT formed by an inter-molecular domain swap. The discovery and characterization of rare variants of AAT and other serpins have historically played a crucial role in the dissection of the structural mechanisms leading to AAT polymer formation. Here, we report a severely deficient shutter region variant, Bologna AAT (N186Y), which was identified in five unrelated subjects with different geographical origins. We characterized the new variant by expression in cellular models in comparison with known polymerogenic AAT variants. Bologna AAT showed secretion deficiency and intracellular accumulation as detergent-insoluble polymers. Extracellular polymers were detected in both the culture media of cells expressing Bologna AAT and in the plasma of a patient homozygous for this variant. Structural modelling revealed that the mutation disrupts the hydrogen bonding network in the AAT shutter region. These data support a crucial coordinating role for asparagine 186 and the importance of this network in promoting formation of the native structure.


Assuntos
Mutação de Sentido Incorreto , Deficiência de alfa 1-Antitripsina/metabolismo , alfa 1-Antitripsina , Substituição de Aminoácidos , Células HEK293 , Humanos , Domínios Proteicos , alfa 1-Antitripsina/biossíntese , alfa 1-Antitripsina/química , alfa 1-Antitripsina/genética , Deficiência de alfa 1-Antitripsina/genética , Deficiência de alfa 1-Antitripsina/patologia
16.
Materials (Basel) ; 14(10)2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-34063488

RESUMO

α1-Antitrypsin is a protease inhibitor belonging to the serpin family. Serpin polymerisation is at the core of a class of genetic conformational diseases called serpinopathies. These polymers are known to be unbranched, flexible, and heterogeneous in size with a beads-on-a-string appearance viewed by negative stain electron microscopy. Here, we use atomic force microscopy and time-lapse dynamic light scattering to measure polymer size and shape for wild-type (M) and Glu342→Lys (Z) α1-antitrypsin, the most common variant that leads to severe pathological deficiency. Our data for small polymers deposited onto mica and in solution reveal a power law relation between the polymer size, namely the end-to-end distance or the hydrodynamic radius, and the polymer mass, proportional to the contour length. We use the scaling concepts of polymer physics to assess that α1-antitrypsin polymers are random linear chains with a low persistence length.

17.
Respir Res ; 22(1): 130, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33910578

RESUMO

BACKGROUND: Fibrinogen is the first qualified prognostic/predictive biomarker for exacerbations in patients with chronic obstructive pulmonary disease (COPD). The IMPACT trial investigated fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy versus FF/VI and UMEC/VI in patients with symptomatic COPD at risk of exacerbations. This analysis used IMPACT trial data to examine the relationship between fibrinogen levels and exacerbation outcomes in patients with COPD. METHODS: 8094 patients with a fibrinogen assessment at Week 16 were included, baseline fibrinogen data were not measured. Post hoc analyses were performed by fibrinogen quartiles and by 3.5 g/L threshold. Endpoints included on-treatment exacerbations and adverse events of special interest (AESIs). RESULTS: Rates of moderate, moderate/severe, and severe exacerbations were higher in the highest versus lowest fibrinogen quartile (0.75, 0.92 and 0.15 vs 0.67, 0.79 and 0.10, respectively). The rate ratios (95% confidence interval [CI]) for exacerbations in patients with fibrinogen levels ≥ 3.5 g/L versus those with fibrinogen levels < 3.5 g/L were 1.03 (0.95, 1.11) for moderate exacerbations, 1.08 (1.00, 1.15) for moderate/severe exacerbations, and 1.30 (1.10, 1.54) for severe exacerbations. There was an increased risk of moderate/severe exacerbation (hazard ratio [95% CI]: highest vs lowest quartile 1.16 [1.04, 1.228]; ≥ 3.5 g/L vs < 3.5 g/L: 1.09 [1.00, 1.16]) and severe exacerbation (1.35 [1.09, 1.69]; 1.27 [1.08, 1.47], respectively) with increasing fibrinogen level. Cardiovascular AESIs were highest in patients in the highest fibrinogen quartile. CONCLUSIONS: Rate and risk of exacerbations was higher in patients with higher fibrinogen levels. This supports the validity of fibrinogen as a predictive biomarker for COPD exacerbations, and highlights the potential use of fibrinogen as an enrichment strategy in trials examining exacerbation outcomes. TRIAL REGISTRATION: NCT02164513.


Assuntos
Fibrinogênio/metabolismo , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/sangue , Idoso , Biomarcadores/sangue , Broncodilatadores/uso terapêutico , Progressão da Doença , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Pulmão/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Regulação para Cima
18.
Bioorg Med Chem Lett ; 41: 127973, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33753261

RESUMO

α1-antitrypsin deficiency is characterised by the misfolding and intracellular polymerisation of mutant α1-antitrypsin protein within the endoplasmic reticulum (ER) of hepatocytes. Small molecules that bind and stabilise Z α1-antitrypsin were identified via a DNA-encoded library screen. A subsequent structure based optimisation led to a series of highly potent, selective and cellular active α1-antitrypsin correctors.


Assuntos
Desenho de Fármacos , Dobramento de Proteína , alfa 1-Antitripsina/metabolismo , Cristalização , Desenvolvimento de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos , Retículo Endoplasmático/metabolismo , Biblioteca Gênica , Hepatócitos/metabolismo , Humanos , Modelos Moleculares , Conformação Proteica , alfa 1-Antitripsina/genética
19.
Magn Reson Med ; 86(1): 320-334, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33645815

RESUMO

PURPOSE: To develop an improved reconstruction method, k-space subtraction with phase and intensity correction (KSPIC), for highly accelerated, subtractive, non-contrast-enhanced MRA. METHODS: The KSPIC method is based on k-space subtraction of complex raw data. It applies a phase-correction procedure to restore the polarity of negative signals caused by subtraction and an intensity-correction procedure to improve background suppression and thereby sparsity. Ten retrospectively undersampled data sets and 10 groups of prospectively undersampled data sets were acquired in 12 healthy volunteers. The performance of KSPIC was compared with another improved reconstruction based on combined magnitude subtraction, as well as with conventional k-space subtraction reconstruction and magnitude subtraction reconstruction, both using quantitative metrics and using subjective quality scoring. RESULTS: In the quantitative evaluation, KSPIC had the best performance in terms of peak SNR, structural similarity index measure, contrast-to-noise ratio of artery-to-background and sharpness, especially at high acceleration factors. The KSPIC method also had the highest subjective scores for all acceleration factors in terms of vessel delineation, image noise and artifact, and background contamination. The acquisition can be accelerated by a factor of 20 without significant decreases of subjective scores. The optimal size of the phase-correction region was found to be 12-20 pixels in this study. CONCLUSION: Compared with combined magnitude subtraction and conventional reconstructions, KSPIC has the best performance in all of the quantitative and qualitative measurements, permitting good image quality to be maintained up to higher accelerations. The KSPIC method has the potential to further reduce the acquisition time of subtractive MRA for clinical examinations.


Assuntos
Angiografia por Ressonância Magnética , Técnica de Subtração , Artefatos , Artéria Femoral/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Estudos Retrospectivos
20.
ERJ Open Res ; 7(1)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33718490

RESUMO

INTRODUCTION: Clinically important deterioration (CID) is a multicomponent measure for assessing disease worsening in chronic obstructive pulmonary disease (COPD). This analysis investigated the prognostic value of a CID event on future clinical outcomes and the effect of single-inhaler triple versus dual therapy on reducing CID risk in patients in the IMPACT trial. METHODS: IMPACT was a phase III, double-blind, 52-week, multicentre trial. Patients with symptomatic COPD and at least one moderate/severe exacerbation in the prior year were randomised 2:2:1 to fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) 100/62.5/25 µg, FF/VI 100/25 µg or UMEC/VI 62.5/25 µg. CID at the time-point of interest was defined as a moderate/severe exacerbation, ≥100 mL decrease in trough forced expiratory volume in 1 s or deterioration in health status (increase of ≥4.0 units in St George's Respiratory Questionnaire total score or increase of ≥2.0 units in COPD Assessment Test score) from baseline. A treatment-independent post hoc prognostic analysis compared clinical outcomes up to week 52 in patients with/without a CID by week 28. A prospective analysis evaluated time to first CID with each treatment. RESULTS: Patients with a CID by week 28 had significantly increased exacerbation rates after week 28, smaller improvements in lung function and health status at week 52 (all p<0.001), and increased risk of all-cause mortality after week 28 versus patients who were CID-free. FF/UMEC/VI significantly reduced CID risk versus dual therapies (all p<0.001). CONCLUSIONS: Prevention of short-term disease worsening was associated with better long-term clinical outcomes. FF/UMEC/VI reduced CID risk versus dual therapies; this effect may improve long-term prognosis in this population.

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