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1.
Cell ; 158(5): 1159-1172, 2014 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-25171414

RESUMEN

In Alzheimer's disease (AD) brain, exposure of axons to Aß causes pathogenic changes that spread retrogradely by unknown mechanisms, affecting the entire neuron. We found that locally applied Aß1-42 initiates axonal synthesis of a defined set of proteins including the transcription factor ATF4. Inhibition of local translation and retrograde transport or knockdown of axonal Atf4 mRNA abolished Aß-induced ATF4 transcriptional activity and cell loss. Aß1-42 injection into the dentate gyrus (DG) of mice caused loss of forebrain neurons whose axons project to the DG. Protein synthesis and Atf4 mRNA were upregulated in these axons, and coinjection of Atf4 siRNA into the DG reduced the effects of Aß1-42 in the forebrain. ATF4 protein and transcripts were found with greater frequency in axons in the brain of AD patients. These results reveal an active role for intra-axonal translation in neurodegeneration and identify ATF4 as a mediator for the spread of AD pathology.


Asunto(s)
Factor de Transcripción Activador 4/análisis , Enfermedad de Alzheimer/patología , Encéfalo/patología , Factor de Transcripción Activador 4/metabolismo , Péptidos beta-Amiloides/genética , Animales , Axones/metabolismo , Encéfalo/citología , Química Encefálica , Factor 2 Eucariótico de Iniciación/metabolismo , Hipocampo , Humanos , Ratones Endogámicos C57BL , Ratas , Factor de Transcripción CHOP/metabolismo
2.
EMBO J ; 43(13): 2789-2812, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38811853

RESUMEN

It has remained unknown how cells reduce cystine taken up from the extracellular space, which is a required step for further utilization of cysteine in key processes such as protein or glutathione synthesis. Here, we show that the thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) is the rate-limiting enzyme for intracellular cystine reduction. When TRP14 is genetically knocked out, cysteine synthesis through the transsulfuration pathway becomes the major source of cysteine in human cells, and knockout of both pathways becomes lethal in C. elegans subjected to proteotoxic stress. TRP14 can also reduce cysteinyl moieties on proteins, rescuing their activities as here shown with cysteinylated peroxiredoxin 2. Txndc17 knockout mice were, surprisingly, protected in an acute pancreatitis model, concomitant with activation of Nrf2-driven antioxidant pathways and upregulation of transsulfuration. We conclude that TRP14 is the evolutionarily conserved enzyme principally responsible for intracellular cystine reduction in C. elegans, mice, and humans.


Asunto(s)
Caenorhabditis elegans , Cisteína , Cistina , Ratones Noqueados , Oxidación-Reducción , Proteoma , Tiorredoxinas , Animales , Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Humanos , Cistina/metabolismo , Ratones , Tiorredoxinas/metabolismo , Tiorredoxinas/genética , Cisteína/metabolismo , Proteoma/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Peroxirredoxinas/metabolismo , Peroxirredoxinas/genética
3.
Immunity ; 51(4): 625-637.e3, 2019 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-31564469

RESUMEN

Preventing aberrant immune responses against the microbiota is essential for the health of the host. Microbiota-shed pathogen-associated molecular patterns translocate from the gut lumen into systemic circulation. Here, we examined the role of hemolymph (insect blood) filtration in regulating systemic responses to microbiota-derived peptidoglycan. Drosophila deficient for the transcription factor Klf15 (Klf15NN) are viable but lack nephrocytes-cells structurally and functionally homologous to the glomerular podocytes of the kidney. We found that Klf15NN flies were more resistant to infection than wild-type (WT) counterparts but exhibited a shortened lifespan. This was associated with constitutive Toll pathway activation triggered by excess peptidoglycan circulating in Klf15NN flies. In WT flies, peptidoglycan was removed from systemic circulation by nephrocytes through endocytosis and subsequent lysosomal degradation. Thus, renal filtration of microbiota-derived peptidoglycan maintains immune homeostasis in Drosophila, a function likely conserved in mammals and potentially relevant to the chronic immune activation seen in settings of impaired blood filtration.


Asunto(s)
Infecciones Bacterianas/inmunología , Tejido Conectivo/fisiología , Drosophila/fisiología , Glomérulos Renales/fisiología , Factores de Transcripción de Tipo Kruppel/genética , Proteínas Nucleares/genética , Podocitos/fisiología , Animales , Animales Modificados Genéticamente , Secreciones Corporales , Proteínas de Drosophila/metabolismo , Endocitosis , Homeostasis , Inmunidad Innata , Mamíferos , Microbiota , Receptores Toll-Like/metabolismo
4.
PLoS Pathog ; 20(3): e1012085, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38484009

RESUMEN

Elaborate viral replication organelles (VROs) are formed to support positive-strand RNA virus replication in infected cells. VRO formation requires subversion of intracellular membranes by viral replication proteins. Here, we showed that the key ATG8f autophagy protein and NBR1 selective autophagy receptor were co-opted by Tomato bushy stunt virus (TBSV) and the closely-related carnation Italian ringspot virus. Knockdown of ATG8f or NBR1 in plants led to reduced tombusvirus replication, suggesting pro-viral function for selective autophagy. BiFC and proximity-labeling experiments showed that the TBSV p33 replication protein interacted with ATG8f and NBR1 to recruit them to VROs. In addition, we observed that several core autophagy proteins, such as ATG1a, ATG4, ATG5, ATG101 and the plant-specific SH3P2 autophagy adaptor proteins were also re-localized to TBSV VROs, suggesting that TBSV hijacks the autophagy machinery in plant cells. We demonstrated that subversion of autophagy components facilitated the recruitment of VPS34 PI3 kinase and enrichment of phospholipids, such as phosphatidylethanolamine and PI3P phosphoinositide in the VRO membranes. Hijacking of autophagy components into TBSV VROs led to inhibition of autophagic flux. We also found that a fraction of the subverted ATG8f and NBR1 was sequestered in biomolecular condensates associated with VROs. We propose that the VRO-associated condensates trap those autophagy proteins, taking them away from the autophagy pathway. Overall, tombusviruses hijack selective autophagy to provide phospholipid-rich membranes for replication and to regulate the antiviral autophagic flux.


Asunto(s)
Tombusvirus , Tombusvirus/fisiología , Saccharomyces cerevisiae/genética , Membranas Intracelulares/metabolismo , Replicación Viral/fisiología , Fosfolípidos/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo , Autofagia , Orgánulos/metabolismo , ARN Viral/genética
5.
BMC Genomics ; 25(1): 353, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38594632

RESUMEN

Mosquitoes are prolific vectors of human pathogens, therefore a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster, is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae (s.l.) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti, however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.


Asunto(s)
Aedes , Infecciones Bacterianas , Micosis , Animales , Humanos , Drosophila melanogaster , Mosquitos Vectores/genética , Aedes/genética , Aedes/microbiología , Bacterias , Hongos/genética
6.
Hum Brain Mapp ; 45(8): e26747, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38825981

RESUMEN

Electroencephalography (EEG) functional connectivity (FC) estimates are confounded by the volume conduction problem. This effect can be greatly reduced by applying FC measures insensitive to instantaneous, zero-lag dependencies (corrected measures). However, numerous studies showed that FC measures sensitive to volume conduction (uncorrected measures) exhibit higher reliability and higher subject-level identifiability. We tested how source reconstruction contributed to the reliability difference of EEG FC measures on a large (n = 201) resting-state data set testing eight FC measures (including corrected and uncorrected measures). We showed that the high reliability of uncorrected FC measures in resting state partly stems from source reconstruction: idiosyncratic noise patterns define a baseline resting-state functional network that explains a significant portion of the reliability of uncorrected FC measures. This effect remained valid for template head model-based, as well as individual head model-based source reconstruction. Based on our findings we made suggestions how to best use spatial leakage corrected and uncorrected FC measures depending on the main goals of the study.


Asunto(s)
Conectoma , Electroencefalografía , Red Nerviosa , Humanos , Electroencefalografía/métodos , Electroencefalografía/normas , Adulto , Conectoma/normas , Conectoma/métodos , Femenino , Masculino , Reproducibilidad de los Resultados , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/fisiología , Adulto Joven , Imagen por Resonancia Magnética/normas , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología
7.
PLoS Pathog ; 18(6): e1010653, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35767596

RESUMEN

Tombusviruses, similar to other (+)RNA viruses, exploit the host cells by co-opting numerous host components and rewiring cellular pathways to build extensive virus-induced replication organelles (VROs) in the cytosol of the infected cells. Most molecular resources are suboptimal in susceptible cells and therefore, tomato bushy stunt virus (TBSV) drives intensive remodeling and subversion of many cellular processes. The authors discovered that the nuclear centromeric CenH3 histone variant (Cse4p in yeast, CENP-A in humans) plays a major role in tombusvirus replication in plants and in the yeast model host. We find that over-expression of CenH3 greatly interferes with tombusvirus replication, whereas mutation or knockdown of CenH3 enhances TBSV replication in yeast and plants. CenH3 binds to the viral RNA and acts as an RNA chaperone. Although these data support a restriction role of CenH3 in tombusvirus replication, we demonstrate that by partially sequestering CenH3 into VROs, TBSV indirectly alters selective gene expression of the host, leading to more abundant protein pool. This in turn helps TBSV to subvert pro-viral host factors into replication. We show this through the example of hypoxia factors, glycolytic and fermentation enzymes, which are exploited more efficiently by tombusviruses to produce abundant ATP locally within the VROs in infected cells. Altogether, we propose that subversion of CenH3/Cse4p from the nucleus into cytosolic VROs facilitates transcriptional changes in the cells, which ultimately leads to more efficient ATP generation in situ within VROs by the co-opted glycolytic enzymes to support the energy requirement of virus replication. In summary, CenH3 plays both pro-viral and restriction functions during tombusvirus replication. This is a surprising novel role for a nuclear histone variant in cytosolic RNA virus replication.


Asunto(s)
Tombusvirus , Adenosina Trifosfato/metabolismo , Histonas/metabolismo , Interacciones Huésped-Patógeno/genética , Humanos , Orgánulos , ARN Viral/genética , Saccharomyces cerevisiae/metabolismo , Nicotiana , Tombusvirus/genética , Tombusvirus/metabolismo , Replicación Viral/genética
8.
New Phytol ; 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38515267

RESUMEN

Positive-strand RNA viruses co-opt organellar membranes for biogenesis of viral replication organelles (VROs). Tombusviruses also co-opt pro-viral cytosolic proteins to VROs. It is currently not known what type of molecular organization keeps co-opted proteins sequestered within membranous VROs. In this study, we employed tomato bushy stunt virus (TBSV) and carnation Italian ringspot virus (CIRV) - Nicotiana benthamiana pathosystems to identify biomolecular condensate formation in VROs. We show that TBSV p33 and the CIRV p36 replication proteins sequester glycolytic and fermentation enzymes in unique condensate substructures associated with membranous VROs. We find that p33 and p36 form droplets in vitro driven by intrinsically disordered region. The replication protein organizes partitioning of co-opted host proteins into droplets. VRO-associated condensates are critical for local adenosine triphosphate production to support energy for virus replication. We find that co-opted endoplasmic reticulum membranes and actin filaments form meshworks within and around VRO condensates, contributing to unique composition and structure. We propose that p33/p36 organize liquid-liquid phase separation of co-opted concentrated host proteins in condensate substructures within membranous VROs. Overall, we demonstrate that subverted membranes and condensate substructures co-exist and are critical for VRO functions. The replication proteins induce and connect the two substructures within VROs.

9.
Am J Med Genet A ; : e63814, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39011850

RESUMEN

We report a 17-year-old male with supravalvular stenosis, initial failure to thrive and delayed early development, short stature, acromelia, dysmorphic facial features, hypertelorism, macrocephaly, syringomyelia, hypertension, and anxiety disorder. Fluorescent in situ hybridization (FISH), chromosomal microarray analysis (CMA), and exome sequencing (ES) were nondiagnostic. Combined optical genome mapping (OGM) and genome sequencing (GS) showed a complex rearrangement including an X chromosome with a 22.5 kb deletion in band Xq28 replaced by a 61.4 kb insertion of duplicated chromosome 7p22.3 material. The deletion removes the distal 3' untranslated region (UTR) of FUNDC2, the entire CMC4 and MTCP1, and the first five exons of BRCC3. Transcriptome analysis revealed absent expression of CMC4 and MTCP1 and BRCC3 with normal transcript level of FUNDC2. The inserted duplication includes only one known gene: UNCX. Similar overlapping Xq28 deletions have been reported to be associated with Moyamoya disease (MMD), short stature, hypergonadotropic hypogonadism (HH), and facial dysmorphism. Although he has short stature, our patient does not have signs of Moyamoya arteriopathy or hypogonadism. The structurally abnormal X chromosome was present in his mother, but not in his unaffected brother, maternal uncle, or maternal grandparents. We propose that the combination of his absent Xq28 and duplicated 7p22.3 genomic material is responsible for his phenotype. This case highlights the potential of combined OGM and GS for detecting complex structural variants compared with standard of care genetic testing such as CMA and ES.

10.
World J Urol ; 42(1): 237, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38625417

RESUMEN

INTRODUCTION: In 2020, bladder cancer (BC) was the seventh most prevalent cancer in the world, with 5-year prevalence of more than 1.7 million cases. Due to the main risk factors-smoking and chemical exposures-associated with BC, it is considered a largely preventable and avoidable cancer. An overview of BC mortality can allow an insight not only into the prevalence of global risk factors, but also into the varying efficiency of healthcare systems worldwide. For this purpose, this study analyzes the national mortality estimates for 2020 and projected future trends up to 2040. MATERIALS AND METHODS: Age-standardized mortality rates per 100,000 person-years of BC for 185 countries by sex were obtained from the GLOBOCAN 2020 database, operated by the International Agency for Research on Cancer (IARC). Mortality rates were stratified according to sex and Human Development Index (HDI). BC deaths were projected up to 2040 on the basis of demographic changes, alongside different scenarios of annually increasing, stable or decreasing mortality rates from the baseline year of 2020. RESULTS: In 2020, nearly three times more men died from BC than women, with more than 210,000 deaths in both sexes combined, worldwide. Regardless of gender, more than half of the total BC deaths were from countries with a very high HDI. According to our projections, while the number of deaths for men can only increase up to 54% (from 159 to around 163-245 thousand), for women it is projected to increase two- to three-fold (from 50 to around 119-176 thousand) by 2040. The burden of BC mortality in countries with a very high HDI versus high HDI appears to converge by 2040 for both sexes. CONCLUSION: Opposite mortality trends by gender highlight the urgent need for immediate interventions to expand anti-tobacco strategies, especially for women. The implementation of more strict occupational health and safety regulations could also prevent exposures associated with BC. Improving the ability to detect BC earlier and access to treatment can have a significant positive impact on reducing mortality rates, minimizing economic costs, and enhancing the quality of life for patients.


Asunto(s)
Calidad de Vida , Neoplasias de la Vejiga Urinaria , Masculino , Humanos , Femenino , Neoplasias de la Vejiga Urinaria/epidemiología , Vejiga Urinaria , Conducta Sexual , Bases de Datos Factuales
11.
J Chem Inf Model ; 64(2): 378-392, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38051630

RESUMEN

Molecular mechanics (MM) simulations have the potential to provide detailed insights into the mechanisms of enzymes that utilize nucleotides as cofactors. In most cases, the activities of these enzymes also require the binding of divalent cations to catalytic sites. However, modeling divalent cations in MM simulations has been challenging. The inclusion of explicit polarization was considered promising, but despite improvements over nonpolarizable force fields and despite the inclusion of "Nonbonded-fix (NB-fix)" corrections, errors in interaction energies of divalent cations with proteins remain large. Importantly, the application of these models fails to reproduce the experimental structural data on Mg2+·Protein·ATP complexes. Focusing on these complexes, here we provide a systematic assessment of the polarizable AMOEBA model and recommend critical changes that substantially improve its predictive performance. Our key results are as follows. We first show that our recent revision of the AMOEBA protein model (AMOEBABIO18-HFC), which contains high field corrections (HFCs) to induced dipoles, dramatically improves Mg2+-protein interaction energies, reducing the mean absolute error (MAE) from 17 to 10 kcal/mol. This further supports the general applicability of AMOEBABIO18-HFC. The inclusion of many-body NB-fix corrections further reduces MAE to 6 kcal/mol, which amounts to less than 2% error. The errors are estimated with respect to vdW-inclusive density functional theory that we benchmark against CCSD(T) calculations and experiments. We also present a new model of ATP with revised polarization parameters to better capture its high field response, as well as new vdW and dihedral parameters. The ATP model accurately predicts experimental Mg2+-ATP binding free energy in the aqueous phase and provides new insights into how Mg2+ associates with ATP. Finally, we show that molecular dynamics (MD) simulations of Mg2+·Kinase·ATP complexes carried out with these improvements lead to a better agreement in global and local catalytic site structures between MD and X-ray crystallography.


Asunto(s)
Amoeba , Cationes Bivalentes , Proteínas/química , Simulación de Dinámica Molecular , Adenosina Trifosfato , Termodinámica
12.
Acta Oncol ; 63: 433-440, 2024 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-38881341

RESUMEN

Recent developments in molecular genetic testing methods (e.g. next-generation sequencing [NGS]-panels) largely accelerated the process of finding the most appropriate targeted therapeutic intervention for cancer patients based on molecularly targetable genetic alterations. In Hungary, a centralized approval system following the recommendation of the National Molecular Tumor Board was launched for the coordination of all aspects of comprehensive genetic profiling (CGP) including patient selection and therapy reimbursement. AIM: The study aims to evaluate the clinical benefit of CGP in our Comprehensive Cancer Center Methods and patients: CGP was introduced into our routine clinical practice in 2021. An NGS-based large (> 500 genes) gene panel was used for cases where molecular genetic testing was approved by the National Molecular Tumor Board. From 2021 until August 2023 163 cases were tested. The majority of them were ECOG 0-1 patients with advanced-stage diseases, histologically rare cancer, or cancers with unknown primary tumours. RESULTS: Seventy-four cases (74 of 163, 45%) had clinically relevant genetic alterations. In 34 patients, the identified variants represented an indication for an approved therapy (approved by the Hungarian authorities, on-label indication), while in 40 cases the recommended therapy did not have an approved indication in Hungary for certain tumour types, but off-label indication could be recommended. Based on our CGP results, 24 patients (24/163; 14.7%) received targeted therapy. Treatment duration was between 1 and 60 months. In total 14 (14/163; 8.5% of the tested cases) patients had a positive clinical response (objective response or stable disease) and were treated for more than 16 weeks. INTERPRETATION: NGS-based CGP was successfully introduced in our institution and a significant number of patients benefited from comprehensive genetic tests. Our preliminary results can serve as the starting point of Drug Rediscovery Protocol (DRUP) studies.


Asunto(s)
Pruebas Genéticas , Secuenciación de Nucleótidos de Alto Rendimiento , Neoplasias , Medicina de Precisión , Humanos , Hungría , Medicina de Precisión/métodos , Neoplasias/genética , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Masculino , Femenino , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Persona de Mediana Edad , Anciano , Adulto , Pruebas Genéticas/métodos , Anciano de 80 o más Años , Adulto Joven , Adolescente , Terapia Molecular Dirigida/métodos , Biomarcadores de Tumor/genética
13.
J Chem Phys ; 160(12)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38530010

RESUMEN

The theory of analytic gradients is presented for the projector-based density functional theory (DFT) embedding approach utilizing the Huzinaga-equation. The advantages of the Huzinaga-equation-based formulation are demonstrated. In particular, it is shown that the projector employed does not appear in the Lagrangian, and the potential risk of numerical problems is avoided at the evaluation of the gradients. The efficient implementation of the analytic gradient theory is presented for approaches where hybrid DFT, second-order Møller-Plesset perturbation theory, or double hybrid DFT are embedded in lower-level DFT environments. To demonstrate the applicability of the method and to gain insight into its accuracy, it is applied to equilibrium geometry optimizations, transition state searches, and potential energy surface scans. Our results show that bond lengths and angles converge rapidly with the size of the embedded system. While providing structural parameters close to high-level quality for the embedded atoms, the embedding approach has the potential to relax the coordinates of the environment as well. Our demonstrations on a 171-atom zeolite and a 570-atom protein system show that the Huzinaga-equation-based embedding can accelerate (double) hybrid gradient computations by an order of magnitude with sufficient active regions and enables affordable force evaluations or geometry optimizations for molecules of hundreds of atoms.

14.
Proc Natl Acad Sci U S A ; 118(1)2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-33376201

RESUMEN

Biogenesis of viral replication organelles (VROs) is critical for replication of positive-strand RNA viruses. In this work, we demonstrate that tomato bushy stunt virus (TBSV) and the closely related carnation Italian ringspot virus (CIRV) hijack the retromer to facilitate building VROs in the surrogate host yeast and in plants. Depletion of retromer proteins, which are needed for biogenesis of endosomal tubular transport carriers, strongly inhibits the peroxisome-associated TBSV and the mitochondria-associated CIRV replication in yeast and in planta. In vitro reconstitution revealed the need for the retromer for the full activity of the viral replicase. The viral p33 replication protein interacts with the retromer complex, including Vps26, Vps29, and Vps35. We demonstrate that TBSV p33-driven retargeting of the retromer into VROs results in delivery of critical retromer cargoes, such as 1) Psd2 phosphatidylserine decarboxylase, 2) Vps34 phosphatidylinositol 3-kinase (PI3K), and 3) phosphatidylinositol 4-kinase (PI4Kα-like). The recruitment of these cellular enzymes by the co-opted retromer is critical for de novo production and enrichment of phosphatidylethanolamine phospholipid, phosphatidylinositol-3-phosphate [PI(3)P], and phosphatidylinositol-4-phosphate [PI(4)P] phosphoinositides within the VROs. Co-opting cellular enzymes required for lipid biosynthesis and lipid modifications suggest that tombusviruses could create an optimized lipid/membrane microenvironment for efficient VRO assembly and protection of the viral RNAs during virus replication. We propose that compartmentalization of these lipid enzymes within VROs helps tombusviruses replicate in an efficient milieu. In summary, tombusviruses target a major crossroad in the secretory and recycling pathways via coopting the retromer complex and the tubular endosomal network to build VROs in infected cells.


Asunto(s)
Proteínas de Transporte Vesicular/metabolismo , Replicación Viral/fisiología , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Interacciones Huésped-Patógeno/genética , Metabolismo de los Lípidos/fisiología , Lípidos/fisiología , Peroxisomas/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilinositoles/metabolismo , ARN Viral/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Tombusvirus/genética , Tombusvirus/metabolismo , Proteínas Virales/metabolismo , Compartimentos de Replicación Viral/metabolismo , Compartimentos de Replicación Viral/fisiología
15.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34737229

RESUMEN

Basal-like breast cancer (BLBC) is the most aggressive subtype of breast tumors with poor prognosis and limited molecular-targeted therapy options. We show that BLBC cells have a high Cys demand and reprogrammed Cys metabolism. Patient-derived BLBC tumors from four different cohorts exhibited elevated expression of the transsulfuration enzyme cystathione ß-synthetase (CBS). CBS silencing (shCBS) made BLBC cells less invasive, proliferate slower, more vulnerable to oxidative stress and cystine (CySSCy) deprivation, prone to ferroptosis, and less responsive to HIF1-α activation under hypoxia. shCBS xenograft tumors grew slower than controls and exhibited impaired angiogenesis and larger necrotic areas. Sulfur metabolite profiling suggested that realigned sulfide/persulfide-inducing functions of CBS are important in BLBC tumor progression. Supporting this, the exclusion of serine, a substrate of CBS for producing Cys but not for producing sulfide/persulfide, did not exacerbate CySSCy deprivation-induced ferroptosis in shCBS BLBC cells. Impaired Tyr phosphorylation was detected in shCBS cells and xenografts, likely due to persulfidation-inhibited phosphatase functions. Overexpression of cystathione γ-lyase (CSE), which can also contribute to cellular sulfide/persulfide production, compensated for the loss of CBS activities, and treatment of shCBS xenografts with a CSE inhibitor further blocked tumor growth. Glutathione and protein-Cys levels were not diminished in shCBS cells or xenografts, but levels of Cys persulfidation and the persulfide-catabolizing enzyme ETHE1 were suppressed. Finally, expression of enzymes of the oxidizing Cys catabolism pathway was diminished, but expression of the persulfide-producing CARS2 was elevated in human BLBC tumors. Hence, the persulfide-producing pathways are major targetable determinants of BLBC pathology that could be therapeutically exploited.


Asunto(s)
Cistationina betasintasa/metabolismo , Cisteína/metabolismo , Neoplasias de la Mama Triple Negativas/enzimología , Animales , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Ferroptosis , Humanos , Ratones SCID , Neovascularización Patológica , Estrés Oxidativo , Sulfuros/metabolismo
16.
Am J Otolaryngol ; 45(2): 104201, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38134853

RESUMEN

PURPOSE: To determine the utility of laryngoscopy in the evaluation of liver transplant patients. METHODS: This study is a single center retrospective cohort review of patients with a diagnosis of liver failure who underwent laryngoscopy or stroboscopy exam as part of a pre-transplant evaluation from 1/1/2010 to 12/31/2022. Patients were identified using ICD 9 and 10 codes for liver failure and CPT codes for flexible laryngoscopy and stroboscopy. Only patients who underwent preoperative liver transplant evaluation were included. Demographic data was collected. Cohort analysis between patients who did or did not undergo further diagnostic intervention was undertaken. RESULTS: 1824 patients were identified. 243 of these patients underwent pre-transplant laryngoscopy or stroboscopy. 26 of the 243 (10.7 %) patients had further diagnostic work up for findings during laryngoscopy, stroboscopy, or head and neck examination. There was one patient who was found to have head and neck cancer and was excluded from the transplant list until this was treated. CONCLUSIONS: Otolaryngologic evaluation of liver transplant patients may be beneficial to identify head and neck pathology.


Asunto(s)
Laringoscopía , Fallo Hepático , Humanos , Estudios Retrospectivos , Cuidados Preoperatorios , Estroboscopía
17.
Trop Anim Health Prod ; 56(5): 180, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38819754

RESUMEN

The aim of the present study was to examine the mammary gland of dromedary camels using ultrasonography, endoscopy and radiography. These techniques are easy to perform in the field and feasible to diagnose pathological conditions of the mammary gland. Udders of 49 slaughtered and 26 adult dromedary camels submitted for necropsy were used for the examinations. Additionally, 11 lactating female dromedary camels were selected for the ultrasonographic udder examination. The transition from the milk ducts into the udder cistern, the teat cistern and the teat canals were examined in individual udders. Teat cistern length, teat end width, teat wall thickness, teat cistern width and middle cistern wall thickness were measured using ultrasonography. The measurements resulted in mean values of the teat cistern length of 37.3 mm, the teat end width of 2.0 mm, the teat wall thickness of 4.4 mm, the teat cistern width of 8.2 mm and the cistern wall thickness of 3.5 mm. The teat wall was differentiated into three layers, a hyperechoic outer layer, a hypoechoic middle layer and a hyperechoic inner layer. The mid cistern wall was hyperechoic. Endoscopic examination is an easy to perform and practicable method for examining the inner structures of the teats of dead animals; however, the feasibility has not been shown in lactating animals yet. Ring-like folds were present in the teat cistern, which protruded horizontally into the lumen. It was also possible to visualize the branchlike transition of the teat cistern into the larger milk ducts. Radiographic examination using barium sulfate contrast medium showed that the teat cistern ends in a network of initially wide but branching and narrowing milk ducts. The two teat canals and cisterns are completely independent of each other and there is no communication between the glandular tissue of the two canals and cisterns.


Asunto(s)
Camelus , Glándulas Mamarias Animales , Animales , Camelus/anatomía & histología , Femenino , Glándulas Mamarias Animales/diagnóstico por imagen , Glándulas Mamarias Animales/anatomía & histología , Endoscopía/veterinaria , Endoscopía/métodos , Radiografía/veterinaria , Ultrasonografía/veterinaria , Ultrasonografía/métodos
18.
J Am Chem Soc ; 145(46): 25372-25381, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37948071

RESUMEN

The adsorption energy of a molecule onto the surface of a material underpins a wide array of applications, spanning heterogeneous catalysis, gas storage, and many more. It is the key quantity where experimental measurements and theoretical calculations meet, with agreement being necessary for reliable predictions of chemical reaction rates and mechanisms. The prototypical molecule-surface system is CO adsorbed on MgO, but despite intense scrutiny from theory and experiment, there is still no consensus on its adsorption energy. In particular, the large cost of accurate many-body methods makes reaching converged theoretical estimates difficult, generating a wide range of values. In this work, we address this challenge, leveraging the latest advances in diffusion Monte Carlo (DMC) and coupled cluster with single, double, and perturbative triple excitations [CCSD(T)] to obtain accurate predictions for CO on MgO. These reliable theoretical estimates allow us to evaluate the inconsistencies in published temperature-programed desorption experiments, revealing that they arise from variations in employed pre-exponential factors. Utilizing this insight, we derive new experimental estimates of the (electronic) adsorption energy with a (more) precise pre-exponential factor. As a culmination of all of this effort, we are able to reach a consensus between multiple theoretical calculations and multiple experiments for the first time. In addition, we show that our recently developed cluster-based CCSD(T) approach provides a low-cost route toward achieving accurate adsorption energies. This sets the stage for affordable and reliable theoretical predictions of chemical reactions on surfaces to guide the realization of new catalysts and gas storage materials.

19.
J Virol ; 96(12): e0016821, 2022 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-35638821

RESUMEN

Positive-strand RNA viruses build large viral replication organelles (VROs) with the help of coopted host factors. Previous works on tomato bushy stunt virus (TBSV) showed that the p33 replication protein subverts the actin cytoskeleton by sequestering the actin depolymerization factor, cofilin, to reduce actin filament disassembly and stabilize the actin filaments. Then, TBSV utilizes the stable actin filaments as "trafficking highways" to deliver proviral host factors into the protective VROs. In this work, we show that the cellular intrinsic restriction factors (CIRFs) also use the actin network to reach VROs and inhibit viral replication. Disruption of the actin filaments by expression of the Legionella RavK protease inhibited the recruitment of plant CIRFs, including the CypA-like Roc1 and Roc2 cyclophilins, and the antiviral DDX17-like RH30 DEAD box helicase into VROs. Conversely, temperature-sensitive actin and cofilin mutant yeasts with stabilized actin filaments reduced the levels of copurified CIRFs, including cyclophilins Cpr1, CypA, Cyp40-like Cpr7, cochaperones Sgt2, the Hop-like Sti1, and the RH30 helicase in viral replicase preparations. Dependence of the recruitment of both proviral and antiviral host factors into VROs on the actin network suggests that there is a race going on between TBSV and its host to exploit the actin network and ultimately to gain the upper hand during infection. We propose that, in the highly susceptible plants, tombusviruses efficiently subvert the actin network for rapid delivery of proviral host factors into VROs and ultimately overcome host restriction factors via winning the recruitment race and overwhelming cellular defenses. IMPORTANCE Replication of positive-strand RNA viruses is affected by the recruitment of host components, which provide either proviral or antiviral functions during virus invasion of infected cells. The delivery of these host factors into the viral replication organelles (VROs), which represent the sites of viral RNA replication, depends on the cellular actin network. Using TBSV, we uncover a race between the virus and its host with the actin network as the central player. We find that in susceptible plants, tombusviruses exploit the actin network for rapid delivery of proviral host factors into VROs and ultimately overcome host restriction factors. In summary, this work demonstrates that the actin network plays a major role in determining the outcome of viral infections in plants.


Asunto(s)
Actinas , Factores de Restricción Antivirales , Biogénesis de Organelos , Tombusvirus , Replicación Viral , Factores Despolimerizantes de la Actina/metabolismo , Actinas/metabolismo , Proteínas Portadoras/metabolismo , Ciclofilinas/metabolismo , Virus ADN/genética , ARN Viral/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/virología , Proteínas de Saccharomyces cerevisiae , Tombusvirus/genética , Tombusvirus/fisiología , Proteínas Virales/metabolismo
20.
PLoS Pathog ; 17(6): e1009680, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34161398

RESUMEN

Positive-strand (+)RNA viruses take advantage of the host cells by subverting a long list of host protein factors and transport vesicles and cellular organelles to build membranous viral replication organelles (VROs) that support robust RNA replication. How RNA viruses accomplish major recruitment tasks of a large number of cellular proteins are intensively studied. In case of tomato bushy stunt virus (TBSV), a single viral replication protein, named p33, carries out most of the recruitment duties. Yet, it is currently unknown how the viral p33 replication protein, which is membrane associated, is capable of the rapid and efficient recruitment of numerous cytosolic host proteins to facilitate the formation of large VROs. In this paper, we show that, TBSV p33 molecules do not recruit each cytosolic host factor one-by-one into VROs, but p33 targets a cytosolic protein interaction hub, namely Rpn11, which interacts with numerous other cytosolic proteins. The highly conserved Rpn11, called POH1 in humans, is the metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates. However, TBSV takes advantage of a noncanonical function of Rpn11 by exploiting Rpn11's interaction with highly abundant cytosolic proteins and the actin network. We provide supporting evidence that the co-opted Rpn11 in coordination with the subverted actin network is used for delivering cytosolic proteins, such as glycolytic and fermentation enzymes, which are readily subverted into VROs to produce ATP locally in support of VRO formation, viral replicase complex assembly and viral RNA replication. Using several approaches, including knockdown of Rpn11 level, sequestering Rpn11 from the cytosol into the nucleus in plants or temperature-sensitive mutation in Rpn11 in yeast, we show the inhibition of recruitment of glycolytic and fermentation enzymes into VROs. The Rpn11-assisted recruitment of the cytosolic enzymes by p33, however, also requires the combined and coordinated role of the subverted actin network. Accordingly, stabilization of the actin filaments by expression of the Legionella VipA effector in yeast and plant, or via a mutation of ACT1 in yeast resulted in more efficient and rapid recruitment of Rpn11 and the selected glycolytic and fermentation enzymes into VROs. On the contrary, destruction of the actin filaments via expression of the Legionella RavK effector led to poor recruitment of Rpn11 and glycolytic and fermentation enzymes. Finally, we confirmed the key roles of Rpn11 and the actin filaments in situ ATP production within TBSV VROs via using a FRET-based ATP-biosensor. The novel emerging theme is that TBSV targets Rpn11 cytosolic protein interaction hub driven by the p33 replication protein and aided by the subverted actin filaments to deliver several co-opted cytosolic pro-viral factors for robust replication within VROs.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Endopeptidasas/metabolismo , Interacciones Huésped-Patógeno/fisiología , Tombusvirus/fisiología , Replicación Viral/fisiología , Citosol/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo
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