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1.
Cell ; 186(2): 346-362.e17, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36638793

RESUMO

Ribosomes frequently stall during mRNA translation, resulting in the context-dependent activation of quality control pathways to maintain proteostasis. However, surveillance mechanisms that specifically respond to stalled ribosomes with an occluded A site have not been identified. We discovered that the elongation factor-1α (eEF1A) inhibitor, ternatin-4, triggers the ubiquitination and degradation of eEF1A on stalled ribosomes. Using a chemical genetic approach, we unveiled a signaling network comprising two E3 ligases, RNF14 and RNF25, which are required for eEF1A degradation. Quantitative proteomics revealed the RNF14 and RNF25-dependent ubiquitination of eEF1A and a discrete set of ribosomal proteins. The ribosome collision sensor GCN1 plays an essential role by engaging RNF14, which directly ubiquitinates eEF1A. The site-specific, RNF25-dependent ubiquitination of the ribosomal protein RPS27A/eS31 provides a second essential signaling input. Our findings illuminate a ubiquitin signaling network that monitors the ribosomal A site and promotes the degradation of stalled translation factors, including eEF1A and the termination factor eRF1.


Assuntos
Proteínas de Ligação a RNA , Transativadores , Proteínas de Transporte/metabolismo , Fatores de Alongamento de Peptídeos/genética , Biossíntese de Proteínas , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Humanos , Células HeLa , Células HEK293 , Proteínas de Ligação a RNA/metabolismo , Transativadores/metabolismo , Fator 1 de Elongação de Peptídeos/metabolismo
2.
Immunity ; 56(1): 43-57.e10, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36630917

RESUMO

There is growing recognition that regionalization of bacterial colonization and immunity along the intestinal tract has an important role in health and disease. Yet, the mechanisms underlying intestinal regionalization and its dysregulation in disease are not well understood. This study found that regional epithelial expression of the transcription factor GATA4 controls bacterial colonization and inflammatory tissue immunity in the proximal small intestine by regulating retinol metabolism and luminal IgA. Furthermore, in mice without jejunal GATA4 expression, the commensal segmented filamentous bacteria promoted pathogenic inflammatory immune responses that disrupted barrier function and increased mortality upon Citrobacter rodentium infection. In celiac disease patients, low GATA4 expression was associated with metabolic alterations, mucosal Actinobacillus, and increased IL-17 immunity. Taken together, these results reveal broad impacts of GATA4-regulated intestinal regionalization on bacterial colonization and tissue immunity, highlighting an elaborate interdependence of intestinal metabolism, immunity, and microbiota in homeostasis and disease.


Assuntos
Infecções por Enterobacteriaceae , Fator de Transcrição GATA4 , Microbioma Gastrointestinal , Mucosa Intestinal , Animais , Humanos , Camundongos , Actinobacillus , Microbioma Gastrointestinal/imunologia , Fator de Transcrição GATA4/metabolismo , Imunidade nas Mucosas , Interleucina-17/imunologia , Interleucina-17/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Intestino Delgado , Simbiose
3.
Cell ; 162(2): 271-286, 2015 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-26186187

RESUMO

Repair of DNA double strand breaks by homologous recombination (HR) is initiated by Rad51 filament nucleation on single-stranded DNA (ssDNA), which catalyzes strand exchange with homologous duplex DNA. BRCA2 and the Rad51 paralogs are tumor suppressors and critical mediators of Rad51. To gain insight into Rad51 paralog function, we investigated a heterodimeric Rad51 paralog complex, RFS-1/RIP-1, and uncovered the molecular basis by which Rad51 paralogs promote HR. Unlike BRCA2, which nucleates RAD-51-ssDNA filaments, RFS-1/RIP-1 binds and remodels pre-synaptic filaments to a stabilized, "open," and flexible conformation, in which the ssDNA is more accessible to nuclease digestion and RAD-51 dissociation rate is reduced. Walker box mutations in RFS-1, which abolish filament remodeling, fail to stimulate RAD-51 strand exchange activity, demonstrating that remodeling is essential for RFS-1/RIP-1 function. We propose that Rad51 paralogs stimulate HR by remodeling the Rad51 filament, priming it for strand exchange with the template duplex.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Proteínas de Transporte/metabolismo , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/metabolismo , Recombinação Homóloga , Rad51 Recombinase/metabolismo , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Mutação , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
4.
Development ; 150(10)2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37129010

RESUMO

Nematode molting is a remarkable process where animals must repeatedly build a new apical extracellular matrix (aECM) beneath a previously built aECM that is subsequently shed. The nuclear hormone receptor NHR-23 (also known as NR1F1) is an important regulator of C. elegans molting. NHR-23 expression oscillates in the epidermal epithelium, and soma-specific NHR-23 depletion causes severe developmental delay and death. Tissue-specific RNAi suggests that nhr-23 acts primarily in seam and hypodermal cells. NHR-23 coordinates the expression of factors involved in molting, lipid transport/metabolism and remodeling of the aECM. NHR-23 depletion causes dampened expression of a nas-37 promoter reporter and a loss of reporter oscillation. The cuticle collagen ROL-6 and zona pellucida protein NOAH-1 display aberrant annular localization and severe disorganization over the seam cells after NHR-23 depletion, while the expression of the adult-specific cuticle collagen BLI-1 is diminished and frequently found in patches. Consistent with these localization defects, the cuticle barrier is severely compromised when NHR-23 is depleted. Together, this work provides insight into how NHR-23 acts in the seam and hypodermal cells to coordinate aECM regeneration during development.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Epitélio/metabolismo , Matriz Extracelular/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo
5.
EMBO Rep ; 25(4): 1962-1986, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38548973

RESUMO

Oncogenic intercellular signaling is regulated by extracellular vesicles (EVs), but the underlying mechanisms remain mostly unclear. Since TCTP (translationally controlled tumor protein) is an EV component, we investigated whether it has a role in genotoxic stress signaling and malignant transformation. By generating a Tctp-inducible knockout mouse model (Tctp-/f-), we report that Tctp is required for genotoxic stress-induced apoptosis signaling via small EVs (sEVs). Human breast cancer cells knocked-down for TCTP show impaired spontaneous EV secretion, thereby reducing sEV-dependent malignant growth. Since Trp53-/- mice are prone to tumor formation, we derived tumor cells from Trp53-/-;Tctp-/f- double mutant mice and describe a drastic decrease in tumori-genicity with concomitant decrease in sEV secretion and content. Remarkably, Trp53-/-;Tctp-/f- mice show highly prolonged survival. Treatment of Trp53-/- mice with sertraline, which inhibits TCTP function, increases their survival. Mechanistically, TCTP binds DDX3, recruiting RNAs, including miRNAs, to sEVs. Our findings establish TCTP as an essential protagonist in the regulation of sEV-signaling in the context of apoptosis and tumorigenicity.


Assuntos
Biomarcadores Tumorais , Neoplasias , Camundongos , Humanos , Animais , Biomarcadores Tumorais/metabolismo , Neoplasias/patologia , Apoptose , Transdução de Sinais
6.
Nature ; 578(7796): 600-604, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051586

RESUMO

Coeliac disease is a complex, polygenic inflammatory enteropathy caused by exposure to dietary gluten that occurs in a subset of genetically susceptible individuals who express either the HLA-DQ8 or HLA-DQ2 haplotypes1,2. The need to develop non-dietary treatments is now widely recognized3, but no pathophysiologically relevant gluten- and HLA-dependent preclinical model exists. Furthermore, although studies in humans have led to major advances in our understanding of the pathogenesis of coeliac disease4, the respective roles of disease-predisposing HLA molecules, and of adaptive and innate immunity in the development of tissue damage, have not been directly demonstrated. Here we describe a mouse model that reproduces the overexpression of interleukin-15 (IL-15) in the gut epithelium and lamina propria that is characteristic of active coeliac disease, expresses the predisposing HLA-DQ8 molecule, and develops villous atrophy after ingestion of gluten. Overexpression of IL-15 in both the epithelium and the lamina propria is required for the development of villous atrophy, which demonstrates the location-dependent central role of IL-15 in the pathogenesis of coeliac disease. In addition, CD4+ T cells and HLA-DQ8 have a crucial role in the licensing of cytotoxic T cells to mediate intestinal epithelial cell lysis. We also demonstrate a role for the cytokine interferon-γ (IFNγ) and the enzyme transglutaminase 2 (TG2) in tissue destruction. By reflecting the complex interaction between gluten, genetics and IL-15-driven tissue inflammation, this mouse model provides the opportunity to both increase our understanding of coeliac disease, and develop new therapeutic strategies.


Assuntos
Doença Celíaca/imunologia , Doença Celíaca/patologia , Glutens/imunologia , Antígenos HLA-DQ/imunologia , Interleucina-15/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Feminino , Antígenos HLA-DQ/genética , Humanos , Interferon gama/imunologia , Interleucina-15/genética , Masculino , Camundongos , Camundongos Transgênicos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo
7.
J Neurosci ; 44(18)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38548338

RESUMO

Hearing loss is a major disability in everyday life and therapeutic interventions to protect hearing would benefit a large portion of the world population. Here we found that mice devoid of the protein kinase suppressor of RAS 1 (KSR1) in their tissues (germline KO mice) exhibit resistance to both cisplatin- and noise-induced permanent hearing loss compared with their wild-type KSR1 littermates. KSR1 is a scaffold protein that brings in proximity the mitogen-activated protein kinase (MAPK) proteins BRAF, MEK1/2 and ERK1/2 and assists in their activation through a phosphorylation cascade induced by both cisplatin and noise insults in the cochlear cells. KSR1, BRAF, MEK1/2, and ERK1/2 are all ubiquitously expressed in the cochlea. Deleting the KSR1 protein tempered down the MAPK phosphorylation cascade in the cochlear cells following both cisplatin and noise insults and conferred hearing protection of up to 30 dB SPL in three tested frequencies in male and female mice. Treatment with dabrafenib, an FDA-approved oral BRAF inhibitor, protected male and female KSR1 wild-type mice from both cisplatin- and noise-induced hearing loss. Dabrafenib treatment did not enhance the protection of KO KSR1 mice, providing evidence dabrafenib works primarily through the MAPK pathway. Thus, either elimination of the KSR1 gene expression or drug inhibition of the MAPK cellular pathway in mice resulted in profound protection from both cisplatin- and noise-induced hearing loss. Inhibition of the MAPK pathway, a cellular pathway that responds to damage in the cochlear cells, can prove a valuable strategy to protect and treat hearing loss.


Assuntos
Cisplatino , Perda Auditiva Provocada por Ruído , Sistema de Sinalização das MAP Quinases , Camundongos Knockout , Proteínas Quinases , Animais , Cisplatino/toxicidade , Camundongos , Feminino , Perda Auditiva Provocada por Ruído/metabolismo , Perda Auditiva Provocada por Ruído/genética , Masculino , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Camundongos Endogâmicos C57BL
8.
Hum Mol Genet ; 32(1): 1-14, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35866299

RESUMO

One of the most significant risk variants for Parkinson's disease (PD), rs356182, is located at the PD-associated locus near the alpha-synuclein (α-syn) encoding gene, SNCA. SNCA-proximal variants, including rs356182, are thought to function in PD risk through enhancers via allele-specific regulatory effects on SNCA expression. However, this interpretation discounts the complex activity of genetic enhancers and possible non-conical functions of α-syn. Here we investigated a novel risk mechanism for rs356182. We use CRISPR-Cas9 in LUHMES cells, a model for dopaminergic midbrain neurons, to generate precise hemizygous lesions at rs356182. The PD-protective (A/-), PD-risk (G/-) and wild-type (A/G) clones were neuronally differentiated and then compared transcriptionally and morphologically. Among the affected genes was SNCA, whose expression was promoted by the PD-protective allele (A) and repressed in its absence. In addition to SNCA, hundreds of genes were differentially expressed and associated with neurogenesis and axonogenesis-an effect not typically ascribed to α-syn. We also found that the transcription factor FOXO3 specifically binds to the rs356182 A-allele in differentiated LUHMES cells. Finally, we compared the results from the rs356182-edited cells to our previously published knockouts of SNCA and found only minimal overlap between the sets of significant differentially expressed genes. Together, the data implicate a risk mechanism for rs356182 in which the risk-allele (G) is associated with abnormal neuron development, independent of SNCA expression. We speculate that these pathological effects manifest as a diminished population of dopaminergic neurons during development leading to the predisposition for PD later in life.


Assuntos
Doença de Parkinson , alfa-Sinucleína , Humanos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Diferenciação Celular/genética , Neurônios Dopaminérgicos/metabolismo , Expressão Gênica , Doença de Parkinson/genética , Doença de Parkinson/metabolismo
9.
Circ Res ; 133(10): 810-825, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37800334

RESUMO

BACKGROUND: Dilated cardiomyopathy (DCM) is a major cause of heart failure and carries a high mortality rate. Myocardial recovery in DCM-related heart failure patients is highly variable, with some patients having little or no response to standard drug therapy. A genome-wide association study may agnostically identify biomarkers and provide novel insight into the biology of myocardial recovery in DCM. METHODS: A genome-wide association study for change in left ventricular ejection fraction was performed in 686 White subjects with recent-onset DCM who received standard pharmacotherapy. Genome-wide association study signals were subsequently functionally validated and studied in relevant cellular models to understand molecular mechanisms that may have contributed to the change in left ventricular ejection fraction. RESULTS: The genome-wide association study identified a highly suggestive locus that mapped to the 5'-flanking region of the CDCP1 (CUB [complement C1r/C1s, Uegf, and Bmp1] domain containing protein 1) gene (rs6773435; P=7.12×10-7). The variant allele was associated with improved cardiac function and decreased CDCP1 transcription. CDCP1 expression was significantly upregulated in human cardiac fibroblasts (HCFs) in response to the PDGF (platelet-derived growth factor) signaling, and knockdown of CDCP1 significantly repressed HCF proliferation and decreased AKT (protein kinase B) phosphorylation. Transcriptomic profiling after CDCP1 knockdown in HCFs supported the conclusion that CDCP1 regulates HCF proliferation and mitosis. In addition, CDCP1 knockdown in HCFs resulted in significantly decreased expression of soluble ST2 (suppression of tumorigenicity-2), a prognostic biomarker for heart failure and inductor of cardiac fibrosis. CONCLUSIONS: CDCP1 may play an important role in myocardial recovery in recent-onset DCM and mediates its effect primarily by attenuating cardiac fibrosis.


Assuntos
Cardiomiopatia Dilatada , Insuficiência Cardíaca , Humanos , Cardiomiopatia Dilatada/metabolismo , Volume Sistólico , Estudo de Associação Genômica Ampla , Função Ventricular Esquerda , Fibrose , Antígenos de Neoplasias/uso terapêutico , Moléculas de Adesão Celular/metabolismo
10.
Proc Natl Acad Sci U S A ; 119(30): e2122227119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35858420

RESUMO

NF-κB-mediated endothelial activation drives leukocyte recruitment and atherosclerosis, in part through adhesion molecules Icam1 and Vcam1. The endothelium is primed for cytokine activation of NF-κB by exposure to low and disturbed blood flow (LDF)but the molecular underpinnings are not fully understood. In an experimental in vivo model of LDF, platelets were required for the increased expression of several RNA-binding splice factors, including polypyrimidine tract binding protein (Ptbp1). This was coordinated with changes in RNA splicing in the NF-κB pathway in primed cells, leading us to examine splice factors as mediators of priming. Using Icam1 and Vcam1 induction by tumor necrosis factor (TNF)-α stimulation as a readout, we performed a CRISPR Cas9 knockout screen and identified a requirement for Ptbp1 in priming. Deletion of Ptbp1 had no effect on cell growth or response to apoptotic stimuli, but reversed LDF splicing patterns and inhibited NF-κB nuclear translocation and transcriptional activation of downstream targets, including Icam1 and Vcam1. In human coronary arteries, elevated PTBP1 correlates with expression of TNF pathway genes and plaque. In vivo, endothelial-specific deletion of Ptbp1 reduced Icam1 expression and myeloid cell infiltration at regions of LDF in atherosclerotic mice, limiting atherosclerosis. This may be mediated, in part, by allowing inclusion of a conserved alternative exon in Ripk1 leading to a reduction in Ripk1 protein. Our data show that Ptbp1, which is induced in a subset of the endothelium by platelet recruitment at regions of LDF, is required for priming of the endothelium for subsequent NF-κB activation, myeloid cell recruitment and atherosclerosis.


Assuntos
Aterosclerose , Proteína de Ligação a Regiões Ricas em Polipirimidinas , Processamento Alternativo , Animais , Aterosclerose/genética , Aterosclerose/metabolismo , Endotélio/metabolismo , Ribonucleoproteínas Nucleares Heterogêneas/genética , Humanos , Inflamação/genética , Inflamação/metabolismo , Camundongos , NF-kappa B/genética , NF-kappa B/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo
11.
Mol Biol Evol ; 40(7)2023 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-37395787

RESUMO

Inference and interpretation of evolutionary processes, in particular of the types and targets of natural selection affecting coding sequences, are critically influenced by the assumptions built into statistical models and tests. If certain aspects of the substitution process (even when they are not of direct interest) are presumed absent or are modeled with too crude of a simplification, estimates of key model parameters can become biased, often systematically, and lead to poor statistical performance. Previous work established that failing to accommodate multinucleotide (or multihit, MH) substitutions strongly biases dN/dS-based inference towards false-positive inferences of diversifying episodic selection, as does failing to model variation in the rate of synonymous substitution (SRV) among sites. Here, we develop an integrated analytical framework and software tools to simultaneously incorporate these sources of evolutionary complexity into selection analyses. We found that both MH and SRV are ubiquitous in empirical alignments, and incorporating them has a strong effect on whether or not positive selection is detected (1.4-fold reduction) and on the distributions of inferred evolutionary rates. With simulation studies, we show that this effect is not attributable to reduced statistical power caused by using a more complex model. After a detailed examination of 21 benchmark alignments and a new high-resolution analysis showing which parts of the alignment provide support for positive selection, we show that MH substitutions occurring along shorter branches in the tree explain a significant fraction of discrepant results in selection detection. Our results add to the growing body of literature which examines decades-old modeling assumptions (including MH) and finds them to be problematic for comparative genomic data analysis. Because multinucleotide substitutions have a significant impact on natural selection detection even at the level of an entire gene, we recommend that selection analyses of this type consider their inclusion as a matter of routine. To facilitate this procedure, we developed, implemented, and benchmarked a simple and well-performing model testing selection detection framework able to screen an alignment for positive selection with two biologically important confounding processes: site-to-site synonymous rate variation, and multinucleotide instantaneous substitutions.


Assuntos
Evolução Molecular , Modelos Genéticos , Genômica , Evolução Biológica , Seleção Genética , Viés , Humanos , Animais , Heurística , Simulação por Computador , Polimorfismo de Nucleotídeo Único , Substituição de Aminoácidos , Polimorfismo Genético , Vírus/genética
12.
Annu Rev Pharmacol Toxicol ; 61: 779-803, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-32997601

RESUMO

Senescence is the consequence of a signaling mechanism activated in stressed cells to prevent proliferation of cells with damage. Senescent cells (Sncs) often develop a senescence-associated secretory phenotype to prompt immune clearance, which drives chronic sterile inflammation and plays a causal role in aging and age-related diseases. Sncs accumulate with age and at anatomical sites of disease. Thus, they are regarded as a logical therapeutic target. Senotherapeutics are a new class of drugs that selectively kill Sncs (senolytics) or suppress their disease-causing phenotypes (senomorphics/senostatics). Since 2015, several senolytics went from identification to clinical trial. Preclinical data indicate that senolytics alleviate disease in numerous organs, improve physical function and resilience, and suppress all causes of mortality, even if administered to the aged. Here, we review the evidence that Sncs drive aging and disease, the approaches to identify and optimize senotherapeutics, and the current status of preclinical and clinical testing of senolytics.


Assuntos
Senescência Celular , Preparações Farmacêuticas , Idoso , Envelhecimento , Humanos , Fenótipo , Transdução de Sinais
13.
PLoS Pathog ; 18(2): e1009831, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35130312

RESUMO

During chronic human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) infection prior to AIDS progression, the vast majority of viral replication is concentrated within B cell follicles of secondary lymphoid tissues. We investigated whether infusion of T cells expressing an SIV-specific chimeric antigen receptor (CAR) and the follicular homing receptor, CXCR5, could successfully kill viral-RNA+ cells in targeted lymphoid follicles in SIV-infected rhesus macaques. In this study, CD4 and CD8 T cells from rhesus macaques were genetically modified to express antiviral CAR and CXCR5 moieties (generating CAR/CXCR5-T cells) and autologously infused into a chronically infected animal. At 2 days post-treatment, the CAR/CXCR5-T cells were located primarily in spleen and lymph nodes both inside and outside of lymphoid follicles. Few CAR/CXCR5-T cells were detected in the ileum, rectum, and lung, and no cells were detected in the bone marrow, liver, or brain. Within follicles, CAR/CXCR5-T cells were found in direct contact with SIV-viral RNA+ cells. We next infused CAR/CXCR5-T cells into ART-suppressed SIV-infected rhesus macaques, in which the animals were released from ART at the time of infusion. These CAR/CXCR5-T cells replicated in vivo within both the extrafollicular and follicular regions of lymph nodes and accumulated within lymphoid follicles. CAR/CXR5-T cell concentrations in follicles peaked during the first week post-infusion but declined to undetectable levels after 2 to 4 weeks. Overall, CAR/CXCR5-T cell-treated animals maintained lower viral loads and follicular viral RNA levels than untreated control animals, and no outstanding adverse reactions were noted. These findings indicate that CAR/CXCR5-T cell treatment is safe and holds promise as a future treatment for the durable remission of HIV.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Receptores CXCR5/imunologia , Receptores de Antígenos Quiméricos/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/terapia , Vírus da Imunodeficiência Símia/imunologia , Animais , Linfócitos B/imunologia , Centro Germinativo/imunologia , Humanos , Imunoterapia , Linfonodos/imunologia , Macaca mulatta , RNA Viral , Receptores CXCR5/metabolismo , Receptores de Antígenos Quiméricos/metabolismo , Carga Viral
14.
Chemistry ; 30(25): e202400390, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38381600

RESUMO

Reaction of [CuH(PPh3)]6 with 1 equiv. of Tl(OTf) results in formation of [Cu6TlH6(PPh3)6][OTf] ([1]OTf]), which can be isolated in good yields. Variable-temperature 1H NMR spectroscopy, in combination with density functional theory (DFT) calculations, confirms the presence of a rare Tl-H orbital interaction. According to DFT, the 1H chemical shift of the Tl-adjacent hydride ligands of [1]+ includes 7.7 ppm of deshielding due to spin-orbit effects from the heavy Tl atom. This study provides valuable new insights into a rare class of metal hydrides, given that [1][OTf] is only the third isolable species reported to contain a Tl-H interaction.

15.
Trends Immunol ; 42(8): 654-657, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34246558

RESUMO

Broadly neutralizing antibodies against rapidly evolving viruses (e.g., HIV-1 and influenza virus), often manifest antigen-binding promiscuity. Based on a recent study, we hypothesize on the significance of antibody polyreactivity in neutralization of rapidly evolving viruses. We propose that polyreactivity contributes to toleration of viral variants and shortens the time for generating neutralizing antibodies.


Assuntos
HIV-1 , Orthomyxoviridae , Imunidade Adaptativa , Anticorpos Neutralizantes , Anticorpos Antivirais , Anticorpos Anti-HIV , Humanos
16.
Nat Chem Biol ; 18(9): 934-941, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35590003

RESUMO

The expansion of the target landscape of covalent inhibitors requires the engagement of nucleophiles beyond cysteine. Although the conserved catalytic lysine in protein kinases is an attractive candidate for a covalent approach, selectivity remains an obvious challenge. Moreover, few covalent inhibitors have been shown to engage the kinase catalytic lysine in animals. We hypothesized that reversible, lysine-targeted inhibitors could provide sustained kinase engagement in vivo, with selectivity driven in part by differences in residence time. By strategically linking benzaldehydes to a promiscuous kinase binding scaffold, we developed chemoproteomic probes that reversibly and covalently engage >200 protein kinases in cells and mice. Probe-kinase residence time was dramatically enhanced by a hydroxyl group ortho to the aldehyde. Remarkably, only a few kinases, including Aurora A, showed sustained, quasi-irreversible occupancy in vivo, the structural basis for which was revealed by X-ray crystallography. We anticipate broad application of salicylaldehyde-based probes to proteins that lack a druggable cysteine.


Assuntos
Lisina , Inibidores de Proteínas Quinases , Animais , Cisteína/metabolismo , Lisina/metabolismo , Camundongos , Ligação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo
17.
Exp Physiol ; 109(7): 1080-1098, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38747161

RESUMO

High altitude (HA) ascent imposes systemic hypoxia and associated risk of acute mountain sickness. Acute hypoxia elicits a hypoxic ventilatory response (HVR), which is augmented with chronic HA exposure (i.e., ventilatory acclimatization; VA). However, laboratory-based HVR tests lack portability and feasibility in field studies. As an alternative, we aimed to characterize area under the curve (AUC) calculations on Fenn diagrams, modified by plotting portable measurements of end-tidal carbon dioxide ( P ETC O 2 ${P_{{\mathrm{ETC}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) against peripheral oxygen saturation ( S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) to characterize and quantify VA during incremental ascent to HA (n = 46). Secondarily, these participants were compared with a separate group following the identical ascent profile whilst self-administering a prophylactic oral dose of acetazolamide (Az; 125 mg BID; n = 20) during ascent. First, morning P ETC O 2 ${P_{{\mathrm{ETC}}{{\mathrm{O}}_{\mathrm{2}}}}}$ and S p O 2 ${S_{{\mathrm{p}}{{\mathrm{O}}_{\mathrm{2}}}}}$ measurements were collected on 46 acetazolamide-free (NAz) lowland participants during an incremental ascent over 10 days to 5160 m in the Nepal Himalaya. AUC was calculated from individually constructed Fenn diagrams, with a trichotomized split on ranked values characterizing the smallest, medium, and largest magnitudes of AUC, representing high (n = 15), moderate (n = 16), and low (n = 15) degrees of acclimatization. After characterizing the range of response magnitudes, we further demonstrated that AUC magnitudes were significantly smaller in the Az group compared to the NAz group (P = 0.0021), suggesting improved VA. These results suggest that calculating AUC on modified Fenn diagrams has utility in assessing VA in large groups of trekkers during incremental ascent to HA, due to the associated portability and congruency with known physiology, although this novel analytical method requires further validation in controlled experiments. HIGHLIGHTS: What is the central question of this study? What are the characteristics of a novel methodological approach to assess ventilatory acclimatization (VA) with incremental ascent to high altitude (HA)? What is the main finding and its importance? Area under the curve (AUC) magnitudes calculated from modified Fenn diagrams were significantly smaller in trekkers taking an oral prophylactic dose of acetazolamide compared to an acetazolamide-free group, suggesting improved VA. During incremental HA ascent, quantifying AUC using modified Fenn diagrams is feasible to assess VA in large groups of trekkers with ascent, although this novel analytical method requires further validation in controlled experiments.


Assuntos
Aclimatação , Acetazolamida , Doença da Altitude , Altitude , Hipóxia , Acetazolamida/farmacologia , Humanos , Aclimatação/fisiologia , Masculino , Adulto , Doença da Altitude/fisiopatologia , Feminino , Hipóxia/fisiopatologia , Inibidores da Anidrase Carbônica/farmacologia , Adulto Jovem , Dióxido de Carbono/metabolismo , Saturação de Oxigênio/fisiologia , Saturação de Oxigênio/efeitos dos fármacos , Ventilação Pulmonar/efeitos dos fármacos , Ventilação Pulmonar/fisiologia
18.
Eur Radiol ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842692

RESUMO

OBJECTIVES: To develop an automated pipeline for extracting prostate cancer-related information from clinical notes. MATERIALS AND METHODS: This retrospective study included 23,225 patients who underwent prostate MRI between 2017 and 2022. Cancer risk factors (family history of cancer and digital rectal exam findings), pre-MRI prostate pathology, and treatment history of prostate cancer were extracted from free-text clinical notes in English as binary or multi-class classification tasks. Any sentence containing pre-defined keywords was extracted from clinical notes within one year before the MRI. After manually creating sentence-level datasets with ground truth, Bidirectional Encoder Representations from Transformers (BERT)-based sentence-level models were fine-tuned using the extracted sentence as input and the category as output. The patient-level output was determined by compilation of multiple sentence-level outputs using tree-based models. Sentence-level classification performance was evaluated using the area under the receiver operating characteristic curve (AUC) on 15% of the sentence-level dataset (sentence-level test set). The patient-level classification performance was evaluated on the patient-level test set created by radiologists by reviewing the clinical notes of 603 patients. Accuracy and sensitivity were compared between the pipeline and radiologists. RESULTS: Sentence-level AUCs were ≥ 0.94. The pipeline showed higher patient-level sensitivity for extracting cancer risk factors (e.g., family history of prostate cancer, 96.5% vs. 77.9%, p < 0.001), but lower accuracy in classifying pre-MRI prostate pathology (92.5% vs. 95.9%, p = 0.002) and treatment history of prostate cancer (95.5% vs. 97.7%, p = 0.03) than radiologists, respectively. CONCLUSION: The proposed pipeline showed promising performance, especially for extracting cancer risk factors from patient's clinical notes. CLINICAL RELEVANCE STATEMENT: The natural language processing pipeline showed a higher sensitivity for extracting prostate cancer risk factors than radiologists and may help efficiently gather relevant text information when interpreting prostate MRI. KEY POINTS: When interpreting prostate MRI, it is necessary to extract prostate cancer-related information from clinical notes. This pipeline extracted the presence of prostate cancer risk factors with higher sensitivity than radiologists. Natural language processing may help radiologists efficiently gather relevant prostate cancer-related text information.

19.
Curr Opin Crit Care ; 30(4): 290-297, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38872371

RESUMO

PURPOSE OF REVIEW: Gastrointestinal (GI) dysfunction limits enteral nutrition (EN) delivery in critical illness and contributes to systemic inflammation. The enteroendocrine (EE) axis plays an integral role in this interface between nutrition, inflammation, and GI function in critical illness. In this review, we present an overview of the EE system with a focus on its role in GI inflammation and function. RECENT FINDINGS: Enteroendocrine cells have been primarily described in their role in macronutrient digestion and absorption. Recent research has expanded on the diverse functions of EE cells including their ability to sense microbial peptides and metabolites and regulate immune function and inflammation. Therefore, EE cells may be both affected by and contribute to many pathophysiologic states and interventions of critical illness such as dysbiosis , inflammation, and alternative EN strategies. In this review, we present an overview of EE cells including their growing role in nonnutrient functions and integrate this understanding into relevant aspects of critical illness with a focus on EN. SUMMARY: The EE system is key in maintaining GI homeostasis in critical illness, and how it is impacted and contributes to outcomes in the setting of dysbiosis , inflammation and different feeding strategies in critical illness should be considered.


Assuntos
Estado Terminal , Nutrição Enteral , Células Enteroendócrinas , Inflamação , Humanos , Inflamação/fisiopatologia , Células Enteroendócrinas/fisiologia , Disbiose/fisiopatologia , Trato Gastrointestinal/fisiopatologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/fisiologia , Microbioma Gastrointestinal/fisiologia , Gastroenteropatias/fisiopatologia , Estado Nutricional/fisiologia
20.
Arterioscler Thromb Vasc Biol ; 43(8): 1349-1361, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37317847

RESUMO

Independent of etiology, hemolytic diseases are associated with thrombosis, inflammation and immune dysregulation, all together contributing to organ damage and poor outcome. Beyond anemia and the loss of the anti-inflammatory functions of red blood cells, hemolysis leads to the release of damage-associated molecular patterns including ADP, hemoglobin, and heme, which act through multiple receptors and signaling pathways fostering a hyperinflammatory and hypercoagulable state. Extracellular free heme is promiscuous alarmin capable of triggering oxido-inflammatory and thrombotic events by inducing the activation of platelets, endothelial and innate cells as well as the coagulation and complement cascades. In this review, we discuss the main mechanisms by which hemolysis and, in particular, heme, drive this thrombo-inflammatory milieu and discuss the consequences of hemolysis on the host response to secondary infections.


Assuntos
Hemoglobinas , Hemólise , Humanos , Hemoglobinas/metabolismo , Eritrócitos/metabolismo , Heme , Inflamação/metabolismo
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