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1.
PLoS Genet ; 20(3): e1011179, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38437227

RESUMO

Recent human genome-wide association studies have identified common missense variants in MARC1, p.Ala165Thr and p.Met187Lys, associated with lower hepatic fat, reduction in liver enzymes and protection from most causes of cirrhosis. Using an exome-wide association study we recapitulated earlier MARC1 p.Ala165Thr and p.Met187Lys findings in 540,000 individuals from five ancestry groups. We also discovered novel rare putative loss of function variants in MARC1 with a phenotype similar to MARC1 p.Ala165Thr/p.Met187Lys variants. In vitro studies of recombinant human MARC1 protein revealed Ala165Thr substitution causes protein instability and aberrant localization in hepatic cells, suggesting MARC1 inhibition or deletion may lead to hepatoprotection. Following this hypothesis, we generated Marc1 knockout mice and evaluated the effect of Marc1 deletion on liver phenotype. Unexpectedly, our study found that whole-body Marc1 deficiency in mouse is not protective against hepatic triglyceride accumulation, liver inflammation or fibrosis. In attempts to explain the lack of the observed phenotype, we discovered that Marc1 plays only a minor role in mouse liver while its paralogue Marc2 is the main Marc family enzyme in mice. Our findings highlight the major difference in MARC1 physiological function between human and mouse.


Assuntos
Estudo de Associação Genômica Ampla , Oximas , Animais , Humanos , Camundongos , Cirrose Hepática
2.
EMBO J ; 41(24): e112006, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36398858

RESUMO

Mitochondria are increasingly recognized as cellular hubs to orchestrate signaling pathways that regulate metabolism, redox homeostasis, and cell fate decisions. Recent research revealed a role of mitochondria also in innate immune signaling; however, the mechanisms of how mitochondria affect signal transduction are poorly understood. Here, we show that the NF-κB pathway activated by TNF employs mitochondria as a platform for signal amplification and shuttling of activated NF-κB to the nucleus. TNF treatment induces the recruitment of HOIP, the catalytic component of the linear ubiquitin chain assembly complex (LUBAC), and its substrate NEMO to the outer mitochondrial membrane, where M1- and K63-linked ubiquitin chains are generated. NF-κB is locally activated and transported to the nucleus by mitochondria, leading to an increase in mitochondria-nucleus contact sites in a HOIP-dependent manner. Notably, TNF-induced stabilization of the mitochondrial kinase PINK1 furthermore contributes to signal amplification by antagonizing the M1-ubiquitin-specific deubiquitinase OTULIN. Overall, our study reveals a role for mitochondria in amplifying TNF-mediated NF-κB activation, both serving as a signaling platform, as well as a transport mode for activated NF-κB to the nuclear.


Assuntos
NF-kappa B , Ubiquitina , NF-kappa B/genética , NF-kappa B/metabolismo , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Transdução de Sinais/fisiologia , Mitocôndrias/metabolismo , Ubiquitinação
3.
N Engl J Med ; 387(4): 332-344, 2022 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-35939579

RESUMO

BACKGROUND: Exome sequencing in hundreds of thousands of persons may enable the identification of rare protein-coding genetic variants associated with protection from human diseases like liver cirrhosis, providing a strategy for the discovery of new therapeutic targets. METHODS: We performed a multistage exome sequencing and genetic association analysis to identify genes in which rare protein-coding variants were associated with liver phenotypes. We conducted in vitro experiments to further characterize associations. RESULTS: The multistage analysis involved 542,904 persons with available data on liver aminotransferase levels, 24,944 patients with various types of liver disease, and 490,636 controls without liver disease. We found that rare coding variants in APOB, ABCB4, SLC30A10, and TM6SF2 were associated with increased aminotransferase levels and an increased risk of liver disease. We also found that variants in CIDEB, which encodes a structural protein found in hepatic lipid droplets, had a protective effect. The burden of rare predicted loss-of-function variants plus missense variants in CIDEB (combined carrier frequency, 0.7%) was associated with decreased alanine aminotransferase levels (beta per allele, -1.24 U per liter; 95% confidence interval [CI], -1.66 to -0.83; P = 4.8×10-9) and with 33% lower odds of liver disease of any cause (odds ratio per allele, 0.67; 95% CI, 0.57 to 0.79; P = 9.9×10-7). Rare coding variants in CIDEB were associated with a decreased risk of liver disease across different underlying causes and different degrees of severity, including cirrhosis of any cause (odds ratio per allele, 0.50; 95% CI, 0.36 to 0.70). Among 3599 patients who had undergone bariatric surgery, rare coding variants in CIDEB were associated with a decreased nonalcoholic fatty liver disease activity score (beta per allele in score units, -0.98; 95% CI, -1.54 to -0.41 [scores range from 0 to 8, with higher scores indicating more severe disease]). In human hepatoma cell lines challenged with oleate, CIDEB small interfering RNA knockdown prevented the buildup of large lipid droplets. CONCLUSIONS: Rare germline mutations in CIDEB conferred substantial protection from liver disease. (Funded by Regeneron Pharmaceuticals.).


Assuntos
Proteínas Reguladoras de Apoptose , Mutação em Linhagem Germinativa , Hepatopatias , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Predisposição Genética para Doença/genética , Predisposição Genética para Doença/prevenção & controle , Humanos , Fígado/metabolismo , Hepatopatias/genética , Hepatopatias/metabolismo , Hepatopatias/prevenção & controle , Transaminases/genética , Sequenciamento do Exoma
4.
PLoS Biol ; 20(4): e3001600, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35421093

RESUMO

The risk of accidental or deliberate misuse of biological research is increasing as biotechnology advances. As open science becomes widespread, we must consider its impact on those risks and develop solutions that ensure security while facilitating scientific progress. Here, we examine the interaction between open science practices and biosecurity and biosafety to identify risks and opportunities for risk mitigation. Increasing the availability of computational tools, datasets, and protocols could increase risks from research with misuse potential. For instance, in the context of viral engineering, open code, data, and materials may increase the risk of release of enhanced pathogens. For this dangerous subset of research, both open science and biosecurity goals may be achieved by using access-controlled repositories or application programming interfaces. While preprints accelerate dissemination of findings, their increased use could challenge strategies for risk mitigation at the publication stage. This highlights the importance of oversight earlier in the research lifecycle. Preregistration of research, a practice promoted by the open science community, provides an opportunity for achieving biosecurity risk assessment at the conception of research. Open science and biosecurity experts have an important role to play in enabling responsible research with maximal societal benefit.


Assuntos
Biosseguridade , Contenção de Riscos Biológicos , Contenção de Riscos Biológicos/métodos
5.
Proc Natl Acad Sci U S A ; 119(23): e2119266119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35639701

RESUMO

The effectiveness of mask wearing at controlling severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission has been unclear. While masks are known to substantially reduce disease transmission in healthcare settings [D. K. Chu et al., Lancet 395, 1973­1987 (2020); J. Howard et al., Proc. Natl. Acad. Sci. U.S.A. 118, e2014564118 (2021); Y. Cheng et al., Science eabg6296 (2021)], studies in community settings report inconsistent results [H. M. Ollila et al., medRxiv (2020); J. Brainard et al., Eurosurveillance 25, 2000725 (2020); T. Jefferson et al., Cochrane Database Syst. Rev. 11, CD006207 (2020)]. Most such studies focus on how masks impact transmission, by analyzing how effective government mask mandates are. However, we find that widespread voluntary mask wearing, and other data limitations, make mandate effectiveness a poor proxy for mask-wearing effectiveness. We directly analyze the effect of mask wearing on SARS-CoV-2 transmission, drawing on several datasets covering 92 regions on six continents, including the largest survey of wearing behavior (n= 20 million) [F. Kreuter et al., https://gisumd.github.io/COVID-19-API-Documentation (2020)]. Using a Bayesian hierarchical model, we estimate the effect of mask wearing on transmission, by linking reported wearing levels to reported cases in each region, while adjusting for mobility and nonpharmaceutical interventions (NPIs), such as bans on large gatherings. Our estimates imply that the mean observed level of mask wearing corresponds to a 19% decrease in the reproduction number R. We also assess the robustness of our results in 60 tests spanning 20 sensitivity analyses. In light of these results, policy makers can effectively reduce transmission by intervening to increase mask wearing.


Assuntos
COVID-19 , Máscaras , COVID-19/epidemiologia , COVID-19/prevenção & controle , Humanos , Política Pública , Inquéritos e Questionários
6.
Genet Epidemiol ; 47(3): 231-248, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36739617

RESUMO

Linkage analysis, a class of methods for detecting co-segregation of genomic segments and traits in families, was used to map disease-causing genes for decades before genotyping arrays and dense SNP genotyping enabled genome-wide association studies in population samples. Population samples often contain related individuals, but the segregation of alleles within families is rarely used because traditional linkage methods are computationally inefficient for larger datasets. Here, we describe Population Linkage, a novel application of Haseman-Elston regression as a method of moments estimator of variance components and their standard errors. We achieve additional computational efficiency by using modern methods for detection of IBD segments and variance component estimation, efficient preprocessing of input data, and minimizing redundant numerical calculations. We also refined variance component models to account for the biases in population-scale methods for IBD segment detection. We ran Population Linkage on four blood lipid traits in over 70,000 individuals from the HUNT and SardiNIA studies, successfully detecting 25 known genetic signals. One notable linkage signal that appeared in both was for low-density lipoprotein (LDL) cholesterol levels in the region near the gene APOE (LOD = 29.3, variance explained = 4.1%). This is the region where the missense variants rs7412 and rs429358, which together make up the ε2, ε3, and ε4 alleles each account for 2.4% and 0.8% of variation in circulating LDL cholesterol. Our results show the potential for linkage analysis and other large-scale applications of method of moments variance components estimation.


Assuntos
Estudo de Associação Genômica Ampla , Modelos Genéticos , Humanos , Fenótipo , LDL-Colesterol/genética , Ligação Genética , Apolipoproteínas E/genética
7.
J Am Chem Soc ; 146(3): 2102-2112, 2024 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-38225538

RESUMO

Recent therapeutic strategies suggest that small peptides can act as aggregation inhibitors of monomeric amyloid-ß (Αß) by inducing structural rearrangements upon complexation. However, characterizing the binding events in such dynamic and transient noncovalent complexes, especially in the presence of natively occurring metal ions, remains a challenge. Here, we deploy a combined transition metal ion Förster resonance energy transfer (tmFRET) and native ion mobility-mass spectrometry (IM-MS) approach to characterize the structure of mass- and charge-selected Aß complexes with Cu(II) ions (a quencher) and a potential aggregation inhibitor, a small neuropeptide named leucine enkephalin (LE). We show conformational changes of monomeric Αß species upon Cu(II)-binding, indicating an uncoiled N-terminus and a close interaction between the C-terminus and the central hydrophobic region. Furthermore, we introduce LE labeled at the N-terminus with a metal-chelating agent, nitrilotriacetic acid (NTA). This allows us to employ tmFRET to probe the binding even in low-abundance and transient Aß-inhibitor-metal ion complexes. Complementary intramolecular distance and global shape information from tmFRET and native IM-MS, respectively, confirmed Cu(II) displacement toward the N-terminus of Αß, which discloses the binding region and the inhibitor's orientation.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Elementos de Transição , Ligantes , Peptídeos beta-Amiloides/química , Metais/química , Íons , Cobre/química
8.
Clin Proteomics ; 21(1): 26, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38565978

RESUMO

BACKGROUND: Clinical samples are irreplaceable, and their transformation into searchable and reusable digital biobanks is critical for conducting statistically empowered retrospective and integrative research studies. Currently, mainly data-independent acquisition strategies are employed to digitize clinical sample cohorts comprehensively. However, the sensitivity of DIA is limited, which is why selected marker candidates are often additionally measured targeted by parallel reaction monitoring. METHODS: Here, we applied the recently co-developed hybrid-PRM/DIA technology as a new intelligent data acquisition strategy that allows for the comprehensive digitization of rare clinical samples at the proteotype level. Hybrid-PRM/DIA enables enhanced measurement sensitivity for a specific set of analytes of current clinical interest by the intelligent triggering of multiplexed parallel reaction monitoring (MSxPRM) in combination with the discovery-driven digitization of the clinical biospecimen using DIA. Heavy-labeled reference peptides were utilized as triggers for MSxPRM and monitoring of endogenous peptides. RESULTS: We first evaluated hybrid-PRM/DIA in a clinical context on a pool of 185 selected proteotypic peptides for tumor-associated antigens derived from 64 annotated human protein groups. We demonstrated improved reproducibility and sensitivity for the detection of endogenous peptides, even at lower concentrations near the detection limit. Up to 179 MSxPRM scans were shown not to affect the overall DIA performance. Next, we applied hybrid-PRM/DIA for the integrated digitization of biobanked melanoma samples using a set of 30 AQUA peptides against 28 biomarker candidates with relevance in molecular tumor board evaluations of melanoma patients. Within the DIA-detected approximately 6500 protein groups, the selected marker candidates such as UFO, CDK4, NF1, and PMEL could be monitored consistently and quantitatively using MSxPRM scans, providing additional confidence for supporting future clinical decision-making. CONCLUSIONS: Combining PRM and DIA measurements provides a new strategy for the sensitive and reproducible detection of protein markers from patients currently being discussed in molecular tumor boards in combination with the opportunity to discover new biomarker candidates.

9.
Eur J Haematol ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023132

RESUMO

BACKGROUND: First-line treatment in patients with acute myeloid leukemia (AML) unfit for intensive therapy is the combination of a hypomethylating agent (HMA) with venetoclax (VEN). However, retrospective data confirming the benefits of this regimen outside of clinical trials have shown conflicting results. METHODS: We performed a multicenter retrospective analysis of outcomes with first-line HMA-VEN versus HMA in AML patients unfit for intensive chemotherapy. RESULTS: A total of 213 patients were included from three German hospitals (125 HMA-VEN, 88 HMA). Median overall survival in the HMA-VEN cohort was 7.9 months (95% confidence interval [CI], 5.1-14.7) versus 4.9 months (3.1-7.1) with HMA. After 1 year, 42% (95% CI, 33-54) and 19% (12-30) of patients were alive, respectively (hazard ratio [HR] for death, 0.64; 95% CI, 0.46-0.88). After adjusting for clinical and molecular baseline characteristics, treatment with HMA-VEN remained significantly associated with both prolonged survival (HR, 0.48; 95% CI, 0.29-0.77) and time to next treatment (HR, 0.63; 95% CI, 0.47-0.85). Patients who achieved recovery of peripheral blood counts had a favorable prognosis (HR for death, 0.52; 95% CI, 0.33-0.84). DISCUSSION: These data align with findings from the pivotal VIALE-A trial and support the use of HMA-VEN in patients unfit for intensive therapy.

10.
J Pathol ; 260(1): 5-16, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36656126

RESUMO

The Ki-67 labeling index (Ki-67 LI) is a strong prognostic marker in prostate cancer, although its analysis requires cumbersome manual quantification of Ki-67 immunostaining in 200-500 tumor cells. To enable automated Ki-67 LI assessment in routine clinical practice, a framework for automated Ki-67 LI quantification, which comprises three different artificial intelligence analysis steps and an algorithm for cell-distance analysis of multiplex fluorescence immunohistochemistry (mfIHC) staining, was developed and validated in a cohort of 12,475 prostate cancers. The prognostic impact of the Ki-67 LI was tested on a tissue microarray (TMA) containing one 0.6 mm sample per patient. A 'heterogeneity TMA' containing three to six samples from different tumor areas in each patient was used to model Ki-67 analysis of multiple different biopsies, and 30 prostate biopsies were analyzed to compare a 'classical' bright field-based Ki-67 analysis with the mfIHC-based framework. The Ki-67 LI provided strong and independent prognostic information in 11,845 analyzed prostate cancers (p < 0.001 each), and excellent agreement was found between the framework for automated Ki-67 LI assessment and the manual quantification in prostate biopsies from routine clinical practice (intraclass correlation coefficient: 0.94 [95% confidence interval: 0.87-0.97]). The analysis of the heterogeneity TMA revealed that the Ki-67 LI of the sample with the highest Gleason score (area under the curve [AUC]: 0.68) was as prognostic as the mean Ki-67 LI of all six foci (AUC: 0.71 [p = 0.24]). The combined analysis of the Ki-67 LI and Gleason score obtained on identical tissue spots showed that the Ki-67 LI added significant additional prognostic information in case of classical International Society of Urological Pathology grades (AUC: 0.82 [p = 0.002]) and quantitative Gleason score (AUC: 0.83 [p = 0.018]). The Ki-67 LI is a powerful prognostic parameter in prostate cancer that is now applicable in routine clinical practice. In the case of multiple cancer-positive biopsies, the sole automated analysis of the worst biopsy was sufficient. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Inteligência Artificial , Neoplasias da Próstata , Masculino , Humanos , Antígeno Ki-67 , Imuno-Histoquímica , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Prognóstico
11.
Mol Cell ; 63(1): 49-59, 2016 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-27320200

RESUMO

Maintaining a fluid bilayer is essential for cell signaling and survival. Lipid saturation is a key factor determining lipid packing and membrane fluidity, and it must be tightly controlled to guarantee organelle function and identity. A dedicated eukaryotic mechanism of lipid saturation sensing, however, remains elusive. Here we show that Mga2, a transcription factor conserved among fungi, acts as a lipid-packing sensor in the ER membrane to control the production of unsaturated fatty acids. Systematic mutagenesis, molecular dynamics simulations, and electron paramagnetic resonance spectroscopy identify a pivotal role of the oligomeric transmembrane helix (TMH) of Mga2 for intra-membrane sensing, and they show that the lipid environment controls the proteolytic activation of Mga2 by stabilizing alternative rotational orientations of the TMH region. This work establishes a eukaryotic strategy of lipid saturation sensing that differs significantly from the analogous bacterial mechanism relying on hydrophobic thickness.


Assuntos
Retículo Endoplasmático/metabolismo , Ácidos Graxos/metabolismo , Membranas Intracelulares/metabolismo , Fluidez de Membrana , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Ácidos Graxos Dessaturases/genética , Ácidos Graxos Dessaturases/metabolismo , Regulação Fúngica da Expressão Gênica , Proteínas de Membrana/química , Proteínas de Membrana/genética , Simulação de Dinâmica Molecular , Mutação , Conformação Proteica em alfa-Hélice , Estabilidade Proteica , Proteólise , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais , Estearoil-CoA Dessaturase , Relação Estrutura-Atividade , Fatores de Transcrição/química , Fatores de Transcrição/genética , Ativação Transcricional
12.
Rheumatol Int ; 44(2): 319-328, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37775621

RESUMO

The aim of this study was to investigate utilisation patterns of prescribed analgesics before, during, and after an exercise therapy and patient education program among patients with knee or hip osteoarthritis. This cohort study is based on data from the nationwide Good Life with osteoarthritis in Denmark (GLA:D®) patient-register linked with national health registries including data on prescribed analgesics. GLA:D® consists of 8-12 weeks of exercise and patient education. We included 35,549 knee/hip osteoarthritis patients starting the intervention between January 2013 and November 2018. Utilisation patterns the year before, 3 months during, and the year after the intervention were investigated using total dispensed defined daily doses (DDDs) per month per 1000 population as outcome. During the year before the intervention, use of prescribed paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids increased with 85%, 79% and 22%, respectively. During the intervention, use of paracetamol decreased with 16% with a stable use the following year. Use of NSAIDs and opioids decreased with 38% and 8%, respectively, throughout the intervention and the year after. Sensitivity analyses indicated that the prescription of most analgesics changed over time. For paracetamol, NSAIDs, and opioids, 10% of analgesic users accounted for 45%, 50%, and 70%, respectively, of the total DDDs dispensed during the study period. In general, analgesic use increased the year before the intervention followed by a decrease during the intervention and the year after. A small proportion of analgesic users accounted for half or more of all paracetamol, NSAIDs, and opioids dispensed during the study period.


Assuntos
Osteoartrite do Quadril , Osteoartrite do Joelho , Humanos , Acetaminofen/uso terapêutico , Osteoartrite do Quadril/tratamento farmacológico , Estudos de Coortes , Educação de Pacientes como Assunto , Analgésicos/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Analgésicos Opioides/uso terapêutico , Osteoartrite do Joelho/tratamento farmacológico , Terapia por Exercício
13.
Proc Natl Acad Sci U S A ; 118(41)2021 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-34607955

RESUMO

The COVID-19 pandemic led to widespread mandates requiring the wearing of face masks, which led to debates on their benefits and possible adverse effects. To that end, the physiological effects at the systemic and at the brain level are of interest. We have investigated the effect of commonly available face masks (FFP2 and surgical) on cerebral hemodynamics and oxygenation, particularly microvascular cerebral blood flow (CBF) and blood/tissue oxygen saturation (StO2), measured by transcranial hybrid near-infrared spectroscopies and on systemic physiology in 13 healthy adults (ages: 23 to 33 y). The results indicate small but significant changes in cerebral hemodynamics while wearing a mask. However, these changes are comparable to those of daily life activities. This platform and the protocol provides the basis for large or targeted studies of the effects of mask wearing in different populations and while performing critical tasks.


Assuntos
Encéfalo/fisiologia , Máscaras , Atividades Cotidianas , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , COVID-19/prevenção & controle , Feminino , Voluntários Saudáveis , Hemodinâmica , Humanos , Masculino , Microcirculação , Monitorização Fisiológica , Oxigênio/metabolismo , SARS-CoV-2 , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
14.
Proc Natl Acad Sci U S A ; 118(7)2021 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-33563755

RESUMO

CD20 is a B cell-specific membrane protein and represents an attractive target for therapeutic antibodies. Despite widespread usage of anti-CD20 antibodies for B cell depletion therapies, the biological function of their target remains unclear. Here, we demonstrate that CD20 controls the nanoscale organization of receptors on the surface of resting B lymphocytes. CRISPR/Cas9-mediated ablation of CD20 in resting B cells resulted in relocalization and interaction of the IgM-class B cell antigen receptor with the coreceptor CD19. This receptor rearrangement led to a transient activation of B cells, accompanied by the internalization of many B cell surface marker proteins. Reexpression of CD20 restored the expression of the B cell surface proteins and the resting state of Ramos B cells. Similarly, treatment of Ramos or naive human B cells with the anti-CD20 antibody rituximab induced nanoscale receptor rearrangements and transient B cell activation in vitro and in vivo. A departure from the resting B cell state followed by the loss of B cell identity of CD20-deficient Ramos B cells was accompanied by a PAX5 to BLIMP-1 transcriptional switch, metabolic reprogramming toward oxidative phosphorylation, and a shift toward plasma cell development. Thus, anti-CD20 engagement or the loss of CD20 disrupts membrane organization, profoundly altering the fate of human B cells.


Assuntos
Antígenos CD20/metabolismo , Linfócitos B/imunologia , Antígenos CD19/metabolismo , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Células Cultivadas , Humanos , Ativação Linfocitária , Receptores de Antígenos de Linfócitos B/metabolismo
15.
Z Gastroenterol ; 62(5): 723-736, 2024 May.
Artigo em Alemão | MEDLINE | ID: mdl-38417809

RESUMO

Technical simulation of diagnostic and therapeutic procedures is of growing relevance for student education and advanced medical training and has already been introduced in the field of ultrasound. This review gives a broad overview on different levels of simulation for ultrasound diagnostics and highlights the technical background of the methodology. A critical review of the literature reveals recommendations for implementing simulation techniques in medical studies and professional ultrasound training. An analysis of strengths and weaknesses shows the advantages of simulation especially in the context of individual learning situations and COVID-19-related restrictions for personal interaction. However, simulation techniques cannot replace the experiences of complex clinical examinations with direct interaction to real patients. Therefore, future applications may focus on repetition and assessment of achieved competencies by using standardized feedback mechanisms in order to preserve the limited resources for practical medical training.


Assuntos
COVID-19 , Humanos , Ultrassonografia/métodos , Currículo , Treinamento por Simulação/métodos , Alemanha , Competência Clínica , Educação Médica/tendências , Educação Médica/métodos , Simulação por Computador
16.
Gene Ther ; 30(5): 407-410, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35264741

RESUMO

Optimizing viral vectors and their properties will be important for improving the effectiveness and safety of clinical gene therapy. However, such research may generate dual-use insights relevant to the enhancement of pandemic pathogens. In particular, reliable and generalizable methods of immune evasion could increase viral fitness sufficient to cause a new pandemic. High potential for misuse is associated with (1) the development of universal genetic elements for immune modulation, (2) specific insights on capsid engineering for antibody evasion applicable to viruses with pandemic potential, and (3) the development of computational methods to inform capsid engineering. These risks may be mitigated by prioritizing non-viral delivery systems, pharmacological immune modulation methods, non-genetic vector surface modifications, and engineering methods specific to AAV and other viruses incapable of unassisted human-to-human transmission. We recommend that computational vector engineering and the publication of associated code and data be limited to AAV until a technical solution for preventing malicious access to viral engineering tools has been established.


Assuntos
Proteínas do Capsídeo , Vetores Genéticos , Humanos , Vetores Genéticos/genética , Proteínas do Capsídeo/genética , Capsídeo , Dependovirus/genética
17.
Hum Mol Genet ; 30(21): 2027-2039, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33961016

RESUMO

Circulating cardiac troponin proteins are associated with structural heart disease and predict incident cardiovascular disease in the general population. However, the genetic contribution to cardiac troponin I (cTnI) concentrations and its causal effect on cardiovascular phenotypes are unclear. We combine data from two large population-based studies, the Trøndelag Health Study and the Generation Scotland Scottish Family Health Study, and perform a genome-wide association study of high-sensitivity cTnI concentrations with 48 115 individuals. We further use two-sample Mendelian randomization to investigate the causal effects of circulating cTnI on acute myocardial infarction (AMI) and heart failure (HF). We identified 12 genetic loci (8 novel) associated with cTnI concentrations. Associated protein-altering variants highlighted putative functional genes: CAND2, HABP2, ANO5, APOH, FHOD3, TNFAIP2, KLKB1 and LMAN1. Phenome-wide association tests in 1688 phecodes and 83 continuous traits in UK Biobank showed associations between a genetic risk score for cTnI and cardiac arrhythmias, metabolic and anthropometric measures. Using two-sample Mendelian randomization, we confirmed the non-causal role of cTnI in AMI (5948 cases, 355 246 controls). We found indications for a causal role of cTnI in HF (47 309 cases and 930 014 controls), but this was not supported by secondary analyses using left ventricular mass as outcome (18 257 individuals). Our findings clarify the biology underlying the heritable contribution to circulating cTnI and support cTnI as a non-causal biomarker for AMI in the general population. Using genetically informed methods for causal inference helps inform the role and value of measuring cTnI in the general population.


Assuntos
Biomarcadores , Genética Populacional , Estudo de Associação Genômica Ampla , Troponina I/genética , Alelos , Mapeamento Cromossômico , Expressão Gênica , Variação Genética , Análise da Randomização Mendeliana , Especificidade de Órgãos , Locos de Características Quantitativas , Troponina T/genética
18.
Environ Microbiol ; 25(11): 2564-2579, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37622480

RESUMO

The type VI secretion system (T6SS) is a contractile nanomachine widespread in Gram-negative bacteria. The T6SS injects effectors into target cells including eukaryotic hosts and competitor microbial cells and thus participates in pathogenesis and intermicrobial competition. Pseudomonas fluorescens MFE01 possesses a single T6SS gene cluster that confers biocontrol properties by protecting potato tubers against the phytopathogen Pectobacterium atrosepticum (Pca). Here, we demonstrate that a functional T6SS is essential to protect potato tuber by reducing the pectobacteria population. Fluorescence microscopy experiments showed that MFE01 displays an aggressive behaviour with an offensive T6SS characterized by continuous and intense T6SS firing activity. Interestingly, we observed that T6SS firing is correlated with rounding of Pectobacterium cells, suggesting delivery of a potent cell wall targeting effector. Mutagenesis coupled with functional assays then revealed that a putative T6SS secreted amidase, Tae3Pf , is mainly responsible for MFE01 toxicity towards Pca. Further studies finally demonstrated that Tae3Pf is toxic when produced in the periplasm, and that its toxicity is counteracted by the Tai3Pf inner membrane immunity protein.


Assuntos
Pectobacterium , Pseudomonas fluorescens , Solanum tuberosum , Sistemas de Secreção Tipo VI , Pseudomonas fluorescens/genética , Pseudomonas fluorescens/metabolismo , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo , Mutagênese , Pectobacterium/genética , Pectobacterium/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
19.
Mod Pathol ; 36(4): 100089, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36788088

RESUMO

Focal T lymphocyte aggregates commonly occur in colorectal cancer; however, their biological significance is unknown. To study focal aggregates of T lymphocytes, a deep learning-based framework for automated identification of T cell accumulations (T cell nests) was developed using CD8, PD-1, CD112R, and Ki67 multiplex fluorescence immunohistochemistry. To evaluate the clinical significance of these parameters, a cohort of 523 colorectal cancers with clinical follow-up data was analyzed. Spatial analysis of locally enriched CD8+ T cell density and cell-to-cell contacts identified T cell nests in the tumor microenvironment of colorectal cancer. CD112R and PD-1 expressions on CD8+ T cells located in T cell nests were found to be elevated compared with those on CD8+ T cells in all other tumor compartments (P < .001 each). Although the highest mean CD112R expression on CD8+ T cells was observed at the invasive margin, the PD-1 expression on CD8+ T cells was elevated in the center of the tumor (P < .001 each). Across all tissue compartments, proliferating CD8+ T cells showed higher relative CD112R and PD-1 expressions than those shown by non-proliferating CD8+ T cells (P < .001 each). Integration of all available spatial and immune checkpoint expression parameters revealed a superior predictive performance for overall survival (area under the curve, 0.65; 95% CI, 0.60-0.70) compared with the commonly used CD8+ tumor-infiltrating lymphocyte density (area under the curve, 0.57; 95% CI, 0.53-0.61; P < .001). Cytotoxic T cells with elevated CD112R and PD-1 expression levels are orchestrated in T cell nests of colorectal cancer and predict favorable patient outcomes, and the spatial nonredundancy underlies fundamental differences between both inhibitory immune checkpoints that provide a rationale for dual anti-CD112R/PD-1 immune checkpoint therapy.


Assuntos
Neoplasias Colorretais , Linfócitos T Citotóxicos , Humanos , Linfócitos T CD8-Positivos , Neoplasias Colorretais/patologia , Linfócitos do Interstício Tumoral , Prognóstico , Receptor de Morte Celular Programada 1/genética , Linfócitos T Citotóxicos/patologia , Microambiente Tumoral , Regulação para Cima
20.
Malar J ; 22(1): 300, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37803381

RESUMO

BACKGROUND: Malaria and dengue fever are the leading causes of acute, undifferentiated febrile illness. In Africa, misdiagnosis of dengue fever as malaria is a common scenario. Through a systematic review of the published literature, this study seeks to estimate the prevalence of dengue and malaria coinfection among acute undifferentiated febrile diseases in Africa. METHODS: Relevant publications were systematically searched in the PubMed, Cochrane Library, and Google Scholar until May 19, 2023. A random-effects meta-analysis and meta-regression were used to summarize and examine the prevalence estimates. RESULTS: Twenty-two studies with 22,803 acute undifferentiated febrile patients from 10 countries in Africa were included. The meta-analysis findings revealed a pooled prevalence of malaria and dengue coinfection of 4.2%, with Central Africa having the highest rate (4.7%), followed by East Africa (2.7%) and West Africa (1.6%). Continent-wide, Plasmodium falciparum and acute dengue virus coinfection prevalence increased significantly from 0.9% during 2008-2013 to 3.8% during 2014-2017 and to 5.5% during 2018-2021 (p = 0.0414). CONCLUSION: There was a high and increasing prevalence of malaria and acute dengue virus coinfection in Africa. Healthcare workers should bear in mind the possibility of dengue infection as a differential diagnosis for acute febrile illness, as well as the possibility of coexisting malaria and dengue in endemic areas. In addition, high-quality multicentre studies are required to verify the above conclusions. Protocol registration number: CRD42022311301.


Assuntos
Coinfecção , Vírus da Dengue , Dengue , Malária , Humanos , Coinfecção/epidemiologia , Coinfecção/diagnóstico , Dengue/epidemiologia , Dengue/diagnóstico , Estudos Transversais , Prevalência , Malária/diagnóstico , África/epidemiologia , Febre/epidemiologia
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