RESUMEN
Cell size is tightly controlled in healthy tissues, but it is unclear how deviations in cell size affect cell physiology. To address this, we measured how the cell's proteome changes with increasing cell size. Size-dependent protein concentration changes are widespread and predicted by subcellular localization, size-dependent mRNA concentrations, and protein turnover. As proliferating cells grow larger, concentration changes typically associated with cellular senescence are increasingly pronounced, suggesting that large size may be a cause rather than just a consequence of cell senescence. Consistent with this hypothesis, larger cells are prone to replicative, DNA-damage-induced, and CDK4/6i-induced senescence. Size-dependent changes to the proteome, including those associated with senescence, are not observed when an increase in cell size is accompanied by an increase in ploidy. Together, our findings show how cell size could impact many aspects of cell physiology by remodeling the proteome and provide a rationale for cell size control and polyploidization.
Asunto(s)
Senescencia Celular , Proteoma , Tamaño de la Célula , Senescencia Celular/fisiología , Daño del ADN , Proteoma/genéticaRESUMEN
Physical exercise is generally beneficial to all aspects of human and animal health, slowing cognitive ageing and neurodegeneration1. The cognitive benefits of physical exercise are tied to an increased plasticity and reduced inflammation within the hippocampus2-4, yet little is known about the factors and mechanisms that mediate these effects. Here we show that 'runner plasma', collected from voluntarily running mice and infused into sedentary mice, reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. Plasma proteomic analysis revealed a concerted increase in complement cascade inhibitors including clusterin (CLU). Intravenously injected CLU binds to brain endothelial cells and reduces neuroinflammatory gene expression in a mouse model of acute brain inflammation and a mouse model of Alzheimer's disease. Patients with cognitive impairment who participated in structured exercise for 6 months had higher plasma levels of CLU. These findings demonstrate the existence of anti-inflammatory exercise factors that are transferrable, target the cerebrovasculature and benefit the brain, and are present in humans who engage in exercise.
Asunto(s)
Enfermedad de Alzheimer , Encefalitis , Enfermedad de Alzheimer/metabolismo , Animales , Clusterina/genética , Clusterina/metabolismo , Células Endoteliales/metabolismo , Humanos , Ratones , ProteómicaRESUMEN
A better mechanistic understanding of virus-host dependencies can help reveal vulnerabilities and identify opportunities for therapeutic intervention. Of particular interest are essential interactions that enable production of viral proteins, as those could target an early step in the virus lifecycle. Here, we use subcellular proteomics, ribosome profiling analyses and reporter assays to detect changes in protein synthesis dynamics during SARS-CoV-2 (CoV2) infection. We identify specific translation factors and molecular chaperones that are used by CoV2 to promote the synthesis and maturation of its own proteins. These can be targeted to inhibit infection, without major toxicity to the host. We also find that CoV2 non-structural protein 1 (Nsp1) cooperates with initiation factors EIF1 and 1A to selectively enhance translation of viral RNA. When EIF1/1A are depleted, more ribosomes initiate translation from a conserved upstream CUG start codon found in all genomic and subgenomic viral RNAs. This results in higher translation of an upstream open reading frame (uORF1) and lower translation of the main ORF, altering the stoichiometry of viral proteins and attenuating infection. Replacing the upstream CUG with AUG strongly inhibits translation of the main ORF independently of Nsp1, EIF1, or EIF1A. Taken together, our work describes multiple dependencies of CoV2 on host biosynthetic networks and proposes a model for dosage control of viral proteins through Nsp1-mediated control of translation start site selection.
Asunto(s)
COVID-19 , ARN Viral , Humanos , ARN Viral/genética , SARS-CoV-2/genética , COVID-19/genética , Factores de Iniciación de Péptidos , Proteínas ViralesRESUMEN
OBJECTIVE: Rapid-onset Obesity with Hypothalamic Dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD), is a severe pediatric disorder of uncertain etiology resulting in hypothalamic dysfunction and frequent sudden death. Frequent co-occurrence of neuroblastic tumors have fueled suspicion of an autoimmune paraneoplastic neurological syndrome (PNS); however, specific anti-neural autoantibodies, a hallmark of PNS, have not been identified. Our objective is to determine if an autoimmune paraneoplastic etiology underlies ROHHAD. METHODS: Immunoglobulin G (IgG) from pediatric ROHHAD patients (n = 9), non-inflammatory individuals (n = 100) and relevant pediatric controls (n = 25) was screened using a programmable phage display of the human peptidome (PhIP-Seq). Putative ROHHAD-specific autoantibodies were orthogonally validated using radioactive ligand binding and cell-based assays. Expression of autoantibody targets in ROHHAD tumor and healthy brain tissue was assessed with immunohistochemistry and mass spectrometry, respectively. RESULTS: Autoantibodies to ZSCAN1 were detected in ROHHAD patients by PhIP-Seq and orthogonally validated in 7/9 ROHHAD patients and 0/125 controls using radioactive ligand binding and cell-based assays. Expression of ZSCAN1 in ROHHAD tumor and healthy human brain tissue was confirmed. INTERPRETATION: Our results support the notion that tumor-associated ROHHAD syndrome is a pediatric PNS, potentially initiated by an immune response to peripheral neuroblastic tumor. ZSCAN1 autoantibodies may aid in earlier, accurate diagnosis of ROHHAD syndrome, thus providing a means toward early detection and treatment. This work warrants follow-up studies to test sensitivity and specificity of a novel diagnostic test. Last, given the absence of the ZSCAN1 gene in rodents, our study highlights the value of human-based approaches for detecting novel PNS subtypes. ANN NEUROL 2022;92:279-291.
Asunto(s)
Enfermedades del Sistema Nervioso Autónomo , Enfermedades del Sistema Endocrino , Enfermedades Hipotalámicas , Síndromes Paraneoplásicos del Sistema Nervioso , Autoanticuerpos , Niño , Humanos , Enfermedades Hipotalámicas/genética , Hipoventilación/genética , Ligandos , Síndromes Paraneoplásicos del Sistema Nervioso/diagnóstico , SíndromeRESUMEN
Eriodictyol is a hydroxylated flavonoid displaying multiple pharmaceutical activities, such as antitumoral, antiviral or neuroprotective. However, its industrial production is limited to extraction from plants due to its inherent limitations. Here, we present the generation of a Streptomyces albidoflavus bacterial factory edited at the genome level for an optimized de novo heterologous production of eriodictyol. For this purpose, an expansion of the Golden Standard toolkit (a Type IIS assembly method based on the Standard European Vector Architecture (SEVA)) has been created, encompassing a collection of synthetic biology modular vectors (adapted for their use in actinomycetes). These vectors have been designed for the assembly of transcriptional units and gene circuits in a plug-and-play manner, as well as for genome editing using CRISPR-Cas9-mediated genetic engineering. These vectors have been used for the optimization of the eriodictyol heterologous production levels in S. albidoflavus by enhancing the flavonoid-3'-hydroxylase (F3'H) activity (by means of a chimera design) and by replacing three native biosynthetic gene clusters in the bacterial chromosome with the plant genes matBC (involved in extracellular malonate uptake and its intracellular activation into malonyl-CoA), therefore allowing more malonyl-CoA to be devoted to the heterologous production of plant flavonoids in this bacterial factory. These experiments have allowed an increase in production of 1.8 times in the edited strain (where the three native biosynthetic gene clusters have been deleted) in comparison with the wild-type strain and a 13 times increase in eriodictyol overproduction in comparison with the non-chimaera version of the F3'H enzyme.
Asunto(s)
Actinobacteria , Actinobacteria/genética , Actinomyces , FlavonoidesRESUMEN
Major histocompatibility complex (MHC)-presented peptides (pMHC) give insight into T cell immune responses, a critical step toward developing a new generation of targeted immunotherapies. Recent instrumentation advances have propelled mass spectrometry to being arguably the most robust technology for discovering and quantifying naturally presented pMHC from cells and tissues. However, sample preparation has remained a major limitation due to time-consuming and labor-intensive workflows. We developed a high-throughput and automated platform with enhanced speed, sensitivity, and reproducibility relative to prior studies. This pipeline is capable of processing up to 96 samples in 6 h or less yielding high-quality pMHC mixtures ready for mass spectrometry. Here, we describe our efforts to optimize purification and mass spectrometer parameters, ultimately allowing us to identify as many as almost 5000 pMHC I and 7400 pMHC II from as little as 2.5 × 107 Raji cells each. We believe that this platform will facilitate and accelerate immunopeptidome profiling and benefit clinical research for immunotherapies.
Asunto(s)
Inmunoterapia , Péptidos , Ligandos , Espectrometría de Masas , Reproducibilidad de los ResultadosRESUMEN
This work represents an overview of the current investigations involving organosulfur compounds and colorectal cancer. The molecules discussed in this review have been investigated regarding their impact on colorectal cancer directly, at the in vitro, in vivo, and clinical stages. Organosulfur compounds may have indirect effects on colorectal cancer, such as due to their modulating effects on the intestinal microbiota or their positive effects on intestinal mucosal health. Here, we focus on their direct effects via the repression of multidrug resistance proteins, triggering of apoptosis (via the inhibition of histone deacetylases, increases in reactive oxygen species, p53 activation, ß-catenin inhibition, damage in the mitochondrial membrane, etc.), activation of TGF-ß, binding to tubulin, inhibition of angiogenesis and metastasis mechanisms, and inhibition of cancer stem cells, among others. In general, the interesting positive effects of these nutraceuticals in in vitro tests must be further analyzed with more in vivo models before conducting clinical trials.
Asunto(s)
Neoplasias Colorrectales , Compuestos de Azufre , Humanos , Apoptosis , Suplementos Dietéticos , Neoplasias Colorrectales/patología , Línea Celular TumoralRESUMEN
A better mechanistic understanding of virus-host interactions can help reveal vulnerabilities and identify opportunities for therapeutic interventions. Of particular interest are essential interactions that enable production of viral proteins, as those could target an early step in the virus lifecycle. Here, we use subcellular proteomics, ribosome profiling analyses and reporter assays to detect changes in polysome composition and protein synthesis during SARS-CoV-2 (CoV2) infection. We identify specific translation factors and molecular chaperones whose inhibition impairs infectious particle production without major toxicity to the host. We find that CoV2 non-structural protein Nsp1 selectively enhances virus translation through functional interactions with initiation factor EIF1A. When EIF1A is depleted, more ribosomes initiate translation from an upstream CUG start codon, inhibiting translation of non-structural genes and reducing viral titers. Together, our work describes multiple dependencies of CoV2 on host biosynthetic networks and identifies druggable targets for potential antiviral development.
RESUMEN
BACKGROUND: Nasal adhesions (NAs) are a known complication of nasal airway surgery. Even minor NAs can lead to significant postoperative nasal airway obstruction (NAO). Division of such NAs often provides much greater relief than anticipated. OBJECTIVE: We examine the impact of NAs at various anatomical sites on nasal airflow and mucosal cooling using computational fluid dynamics (CFD) and multiple test subjects. METHODS: CT scans of healthy adult subjects were used to construct three-dimensional nasal airway computational models. A single virtual 2.5 mm diameter NA was placed at one of five sites commonly seen following NAO surgery within each nasal cavity bilaterally, resulting in 10 NA models and 1 NA-free control for each subject. CFD analysis was performed on each NA model and compared with the subject's NA-free control model. RESULTS: 4 subjects were recruited to create 44 computational models. The NAs caused the airflow streamlines to separate, leading to a statistically significant increase in mucosal temperature immediately downstream to the NAs (wake region). Changes in the mucosal temperature in the wake region of the NAs were most prominent in anteriorly located NAs with a mean increase of 1.62â °C for the anterior inferior turbinate NAs (P < .001) and 0.63â °C for the internal valve NAs (P < .001). CONCLUSION: NAs result in marked disruption to airflow patterns and reduced mucosal cooling on critical surfaces, particularly in the wake region. Reduced wake region mucosal cooling may be a contributing factor to the exaggerated perception of nasal obstruction experienced by patients with NAs.
Asunto(s)
Obstrucción Nasal , Adulto , Humanos , Obstrucción Nasal/cirugía , Hidrodinámica , Cavidad Nasal/diagnóstico por imagen , Cornetes Nasales/cirugía , Nasofaringe , Simulación por ComputadorRESUMEN
The modern environmental management literature stresses the need for community involvement to identify indicators to monitor progress towards sustainable development and environmental management goals. The purpose of this paper is to assess the impact of participatory processes on sustainability indicator identification and environmental management in three disparate case studies. The first is a process of developing partnerships between First Nations communities, environmental groups, and forestry companies to resolve conflicts over forest management in Western Canada. The second describes a situation in Botswana where local pastoral communities worked with development researchers to reduce desertification. The third case study details an on-going government led process of developing sustainability indicators in Guernsey, UK, that was designed to monitor the environmental, social, and economic impacts of changes in the economy. The comparative assessment between case studies allows us to draw three primary conclusions. (1) The identification and collection of sustainability indicators not only provide valuable databases for making management decisions, but the process of engaging people to select indicators also provides an opportunity for community empowerment that conventional development approaches have failed to provide. (2) Multi-stakeholder processes must formally feed into decision-making forums or they risk being viewed as irrelevant by policy-makers and stakeholders. (3) Since ecological boundaries rarely meet up with political jurisdictions, it is necessary to be flexible when choosing the scale at which monitoring and decision-making occurs. This requires an awareness of major environmental pathways that run through landscapes to understand how seemingly remote areas may be connected in ways that are not immediately apparent.