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1.
Nat Immunol ; 20(10): 1348-1359, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31406382

RESUMO

Helper T cells actively communicate with adjacent cells by secreting soluble mediators, yet crosstalk between helper T cells and endothelial cells remains poorly understood. Here we found that placental growth factor (PlGF), a homolog of the vascular endothelial growth factor that enhances an angiogenic switch in disease, was selectively secreted by the TH17 subset of helper T cells and promoted angiogenesis. Interestingly, the 'angio-lymphokine' PlGF, in turn, specifically induced the differentiation of pathogenic TH17 cells by activating the transcription factor STAT3 via binding to its receptors and replaced the activity of interleukin-6 in the production of interleukin-17, whereas it suppressed the generation of regulatory T cells. Moreover, T cell-derived PlGF was required for the progression of autoimmune diseases associated with TH17 differentiation, including experimental autoimmune encephalomyelitis and collagen-induced arthritis, in mice. Collectively, our findings provide insights into the PlGF-dictated links among angiogenesis, TH17 cell development and autoimmunity.


Assuntos
Artrite Experimental/imunologia , Encefalomielite Autoimune Experimental/imunologia , Fator de Crescimento Placentário/metabolismo , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Animais , Autoimunidade , Diferenciação Celular , Células Cultivadas , Interleucina-17/metabolismo , Interleucina-6/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Neovascularização Patológica , Fator de Crescimento Placentário/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
2.
Nature ; 633(8030): 594-600, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39294349

RESUMO

Climate models indicate that dry extremes will be exacerbated in many regions of the world1,2. However, confidence in the magnitude and timing of these projected changes remains low3,4, leaving societies largely unprepared5,6. Here we show that constraining model projections with observations using a newly proposed emergent constraint (EC) reduces the uncertainty in predictions of a core drought indicator, the longest annual dry spell (LAD), by 10-26% globally. Our EC-corrected projections reveal that the increase in LAD will be 42-44% greater, on average, than 'mid-range' or 'high-end' future forcing scenarios currently indicate. These results imply that by the end of this century, the global mean land-only LAD could be 10 days longer than currently expected. Using two generations of climate models, we further uncover global regions for which historical LAD biases affect the magnitude of projected LAD increases, and we explore the role of land-atmosphere feedbacks therein. Our findings reveal regions with potentially higher- and earlier-than-expected drought risks for societies and ecosystems, and they point to possible mechanisms underlying the biases in the current generation of climate models.


Assuntos
Modelos Climáticos , Secas , Atmosfera/química , Secas/estatística & dados numéricos , Ecossistema , Fatores de Tempo , Incerteza
3.
Proc Natl Acad Sci U S A ; 121(36): e2405138121, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39190352

RESUMO

The neural pathways that start human color vision begin in the complex synaptic network of the foveal retina where signals originating in long (L), middle (M), and short (S) wavelength-sensitive cone photoreceptor types are compared through antagonistic interactions, referred to as opponency. In nonhuman primates, two cone opponent pathways are well established: an L vs. M cone circuit linked to the midget ganglion cell type, often called the red-green pathway, and an S vs. L + M cone circuit linked to the small bistratified ganglion cell type, often called the blue-yellow pathway. These pathways have been taken to correspond in human vision to cardinal directions in a trichromatic color space, providing the parallel inputs to higher-level color processing. Yet linking cone opponency in the nonhuman primate retina to color mechanisms in human vision has proven particularly difficult. Here, we apply connectomic reconstruction to the human foveal retina to trace parallel excitatory synaptic outputs from the S-ON (or "blue-cone") bipolar cell to the small bistratified cell and two additional ganglion cell types: a large bistratified ganglion cell and a subpopulation of ON-midget ganglion cells, whose synaptic connections suggest a significant and unique role in color vision. These two ganglion cell types are postsynaptic to both S-ON and L vs. M opponent midget bipolar cells and thus define excitatory pathways in the foveal retina that merge the cardinal red-green and blue-yellow circuits, with the potential for trichromatic cone opponency at the first stage of human vision.


Assuntos
Percepção de Cores , Visão de Cores , Fóvea Central , Células Fotorreceptoras Retinianas Cones , Células Ganglionares da Retina , Humanos , Fóvea Central/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Células Fotorreceptoras Retinianas Cones/metabolismo , Visão de Cores/fisiologia , Células Ganglionares da Retina/fisiologia , Percepção de Cores/fisiologia , Células Bipolares da Retina/fisiologia , Células Bipolares da Retina/metabolismo , Retina/fisiologia , Masculino , Feminino , Adulto , Conectoma , Vias Visuais/fisiologia
4.
Circ Res ; 135(5): e114-e132, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-38989585

RESUMO

BACKGROUND: Atherosclerosis is a chronic inflammatory disease causing a fatal plaque rupture, and its key aspect is a failure to resolve inflammation. We hypothesize that macrophage-targeted near-infrared fluorescence emitting photoactivation could simultaneously assess macrophage/lipid-rich plaques in vivo and facilitate inflammation resolution. METHODS: We fabricated a Dectin-1-targeted photoactivatable theranostic agent through the chemical conjugation of the near-infrared fluorescence-emitting photosensitizer chlorin e6 and the Dectin-1 ligand laminarin (laminarin-chlorin e6 [LAM-Ce6]). Intravascular photoactivation by a customized fiber-based diffuser after administration of LAM-Ce6 effectively reduced inflammation in the targeted plaques of atherosclerotic rabbits in vivo as serially assessed by dual-modal optical coherence tomography-near-infrared fluorescence structural-molecular catheter imaging after 4 weeks. RESULTS: The number of apoptotic macrophages peaked at 1 day after laser irradiation and then resolved until 4 weeks. Autophagy was strongly augmented 1 hour after the light therapy, with the formation of autophagolysosomes. LAM-Ce6 photoactivation increased the terminal deoxynucleotidyl transferase dUTP (deoxyuridine triphosphate) nick end labeling/RAM11 (rabbit monocyte/macrophage antibody)- and MerTK (c-Mer tyrosine kinase)-positive cells in the plaques, suggesting enhanced efferocytosis. In line with inflammation resolution, photoactivation reduced the plaque burden through fibrotic replacement via the TGF (transforming growth factor)-ß/CTGF (connective tissue growth factor) pathway. CONCLUSIONS: Optical coherence tomography-near-infrared fluorescence imaging-guided macrophage Dectin-1-targetable photoactivation could induce the transition of macrophage/lipid-rich plaques into collagen-rich lesions through autophagy-mediated inflammation resolution and TGF-ß-dependent fibrotic replacement. This novel strategy offers a new opportunity for the catheter-based theranostic strategy.


Assuntos
Clorofilídeos , Imagem Multimodal , Fármacos Fotossensibilizantes , Placa Aterosclerótica , Porfirinas , Tomografia de Coerência Óptica , Animais , Placa Aterosclerótica/diagnóstico por imagem , Coelhos , Imagem Multimodal/métodos , Tomografia de Coerência Óptica/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Macrófagos/metabolismo , Nanomedicina Teranóstica/métodos , Camundongos , Masculino , Autofagia , c-Mer Tirosina Quinase/metabolismo , Apoptose
5.
EMBO Rep ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39191946

RESUMO

Aberrant mitochondrial fission/fusion dynamics are frequently associated with pathologies, including cancer. We show that alternative splice variants of the fission protein Drp1 (DNM1L) contribute to the complexity of mitochondrial fission/fusion regulation in tumor cells. High tumor expression of the Drp1 alternative splice variant lacking exon 16 relative to other transcripts is associated with poor outcome in ovarian cancer patients. Lack of exon 16 results in Drp1 localization to microtubules and decreased association with mitochondrial fission sites, culminating in fused mitochondrial networks, enhanced respiration, changes in metabolism, and enhanced pro-tumorigenic phenotypes in vitro and in vivo. These effects are inhibited by siRNAs designed to specifically target the endogenously expressed transcript lacking exon 16. Moreover, lack of exon 16 abrogates mitochondrial fission in response to pro-apoptotic stimuli and leads to decreased sensitivity to chemotherapeutics. These data emphasize the pathophysiological importance of Drp1 alternative splicing, highlight the divergent functions and consequences of changing the relative expression of Drp1 splice variants in tumor cells, and strongly warrant consideration of alternative splicing in future studies focused on Drp1.

6.
Proc Natl Acad Sci U S A ; 120(18): e2300545120, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37098066

RESUMO

The Old World macaque monkey and New World common marmoset provide fundamental models for human visual processing, yet the human ancestral lineage diverged from these monkey lineages over 25 Mya. We therefore asked whether fine-scale synaptic wiring in the nervous system is preserved across these three primate families, despite long periods of independent evolution. We applied connectomic electron microscopy to the specialized foveal retina where circuits for highest acuity and color vision reside. Synaptic motifs arising from the cone photoreceptor type sensitive to short (S) wavelengths and associated with "blue-yellow" (S-ON and S-OFF) color-coding circuitry were reconstructed. We found that distinctive circuitry arises from S cones for each of the three species. The S cones contacted neighboring L and M (long- and middle-wavelength sensitive) cones in humans, but such contacts were rare or absent in macaques and marmosets. We discovered a major S-OFF pathway in the human retina and established its absence in marmosets. Further, the S-ON and S-OFF chromatic pathways make excitatory-type synaptic contacts with L and M cone types in humans, but not in macaques or marmosets. Our results predict that early-stage chromatic signals are distinct in the human retina and imply that solving the human connectome at the nanoscale level of synaptic wiring will be critical for fully understanding the neural basis of human color vision.


Assuntos
Visão de Cores , Conectoma , Animais , Humanos , Callithrix , Percepção de Cores/fisiologia , Retina/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Macaca , Cercopithecidae
7.
Proc Natl Acad Sci U S A ; 120(20): e2302937120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155852

RESUMO

Implantation is the first direct encounter between the embryo and uterus during pregnancy, and Hbegf is the earliest known molecular signaling for embryo-uterine crosstalk during implantation. The downstream effectors of heparin-binding EGF (HB-EGF) in implantation remain elusive due to the complexity of EGF receptor family. This study shows that the formation of implantation chamber (crypt) triggered by HB-EGF is disrupted by uterine deletion of Vangl2, a key planar cell polarity component (PCP). We found that HB-EGF binds to ERBB2 and ERBB3 to recruit VANGL2 for tyrosine phosphorylation. Using in vivo models, we show that uterine VAGL2 tyrosine phosphorylation is suppressed in Erbb2/Erbb3 double conditional knockout mice. In this context, severe implantation defects in these mice lend support to the critical role of HB-EGF-ERBB2/3-VANGL2 in establishing a two-way dialogue between the blastocyst and uterus. In addition, the result addresses an outstanding question how VANGL2 is activated during implantation. Taken together, these observations reveal that HB-EGF regulates the implantation process by influencing uterine epithelial cell polarity comprising VANGL2.


Assuntos
Polaridade Celular , Implantação do Embrião , Animais , Feminino , Camundongos , Gravidez , Polaridade Celular/fisiologia , Implantação do Embrião/fisiologia , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/genética , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/metabolismo , Camundongos Knockout , Transdução de Sinais , Tirosina
8.
EMBO J ; 40(24): e108684, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34726281

RESUMO

Plant photoperiodic growth is coordinated by interactions between circadian clock and light signaling networks. How post-translational modifications of clock proteins affect these interactions to mediate rhythmic growth remains unclear. Here, we identify five phosphorylation sites in the Arabidopsis core clock protein TIMING OF CAB EXPRESSION 1 (TOC1) which when mutated to alanine eliminate detectable phosphorylation. The TOC1 phospho-mutant fails to fully rescue the clock, growth, and flowering phenotypes of the toc1 mutant. Further, the TOC1 phospho-mutant shows advanced phase, a faster degradation rate, reduced interactions with PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) and HISTONE DEACETYLASE 15 (HDA15), and poor binding at pre-dawn hypocotyl growth-related genes (PHGs), leading to a net de-repression of hypocotyl growth. NUCLEAR FACTOR Y subunits B and C (NF-YB/C) stabilize TOC1 at target promoters, and this novel trimeric complex (NF-TOC1) acts as a transcriptional co-repressor with HDA15 to inhibit PIF-mediated hypocotyl elongation. Collectively, we identify a molecular mechanism suggesting how phosphorylation of TOC1 alters its phase, stability, and physical interactions with co-regulators to precisely phase PHG expression to control photoperiodic hypocotyl growth.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Fator de Ligação a CCAAT/metabolismo , Mutação , Fatores de Transcrição/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Fosforilação , Proteólise , Transdução de Sinais , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
9.
J Immunol ; 210(11): 1687-1699, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37042681

RESUMO

Although CD4+CD25+FOXP3+ regulatory T (TREG) cells have been studied in patients with COVID-19, changes in the TREG cell population have not been longitudinally examined during the course of COVID-19. In this study, we longitudinally investigated the quantitative and qualitative changes in the TREG cell population in patients with COVID-19. We found that the frequencies of total TREG cells and CD45RA-FOXP3hi activated TREG cells were significantly increased 15-28 d postsymptom onset in severe patients, but not in mild patients. TREG cells from severe patients exhibited not only increased proliferation but also enhanced apoptosis, suggesting functional derangement of the TREG cell population during severe COVID-19. The suppressive functions of the TREG cell population did not differ between patients with severe versus mild COVID-19. The frequency of TREG cells inversely correlated with SARS-CoV-2-specific cytokine production by CD4+ T cells and their polyfunctionality in patients with mild disease, suggesting that TREG cells are major regulators of virus-specific CD4+ T cell responses during mild COVID-19. However, such correlations were not observed in patients with severe disease. Thus, in this study, we describe distinctive changes in the TREG cell population in patients with severe and mild COVID-19. Our study provides a deep understanding of host immune responses upon SARS-CoV-2 infection in regard to TREG cells.


Assuntos
COVID-19 , Linfócitos T Reguladores , Humanos , SARS-CoV-2 , Linfócitos T CD4-Positivos , Subunidade alfa de Receptor de Interleucina-2 , Fatores de Transcrição Forkhead
10.
J Immunol ; 210(12): 1974-1989, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37163338

RESUMO

The gasdermins are a family of pore-forming proteins that has recently been suggested to play a central role in pyroptosis. In this study, we describe the novel roles of gasdermins in the biogenesis of apoptotic cell-derived exosomes. In apoptotic human HeLa and HEK293 cells, GSDMA, GSDMC, GSDMD, and GSDME increased the release of apoptotic exosomes. GSDMB and DFNB59, in contrast, negatively affected the release of apoptotic exosomes. GSDME at its full-length and cleaved forms was localized in the exosomes and exosomal membrane. Full-length and cleaved forms of GSDME are suggested to increase Ca2+ influx to the cytosol through endosomal pores and thus increase the biogenesis of apoptotic exosomes. In addition, the GSDME-mediated biogenesis of apoptotic exosomes depended on the ESCRT-III complex and endosomal recruitment of Ca2+-dependent proteins, that is, annexins A2 and A7, the PEF domain family proteins sorcin and grancalcin, and the Bro1 domain protein HD-PTP. Therefore, we propose that the biogenesis of apoptotic exosomes begins when gasdermin-mediated endosomal pores increase cytosolic Ca2+, continues through the recruitment of annexin-sorcin/grancalcin-HD-PTP, and is completed when the ESCRT-III complex synthesizes intraluminal vesicles in the multivesicular bodies of dying cells. Finally, we found that GSDME-bearing tumors released apoptotic exosomes to induce inflammatory responses in the in vivo mouse 4T1 orthotropic model of BALB/c breast cancer. The data indicate that the switch from apoptosis to pyroptosis could drive the transfer of mass signals to nearby or distant living cells and tissues by way of extracellular vesicles, and that gasdermins play critical roles in that process.

11.
Proc Natl Acad Sci U S A ; 119(30): e2119048119, 2022 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-35858411

RESUMO

The major challenges in pancreatic ductal adenocarcinoma (PDAC) management are local or distant metastasis and limited targeted therapeutics to prevent it. To identify a druggable target in tumor secretome and to explore its therapeutic intervention, we performed a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis of tumors obtained from a patient-derived xenograft model of PDAC. Galectin-3 binding protein (Gal-3BP) is identified as a highly secreted protein, and its overexpression is further validated in multiple PDAC tumors and primary cells. Knockdown and exogenous treatment of Gal-3BP showed that it is required for PDAC cell proliferation, migration, and invasion. Mechanistically, we revealed that Gal-3BP enhances galectin-3-mediated epidermal growth factor receptor signaling, leading to increased cMyc and epithelial-mesenchymal transition. To explore the clinical impact of these findings, two antibody clones were developed, and they profoundly abrogated the metastasis of PDAC cells in vivo. Altogether, our data demonstrate that Gal-3BP is an important therapeutic target in PDAC, and we propose its blockade by antibody as a therapeutic option for suppressing PDAC metastasis.


Assuntos
Antígenos de Neoplasias , Antineoplásicos Imunológicos , Biomarcadores Tumorais , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/imunologia , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores Tumorais/antagonistas & inibidores , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/imunologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/secundário , Carcinoma Ductal Pancreático/terapia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Cromatografia Líquida , Transição Epitelial-Mesenquimal , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Proteômica , Secretoma , Espectrometria de Massas em Tandem , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Proc Natl Acad Sci U S A ; 119(51): e2203711119, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36512497

RESUMO

The selenium-binding protein 1 (SELENBP1) has been reported to be up-regulated in the prefrontal cortex (PFC) of schizophrenia patients in postmortem reports. However, no causative link between SELENBP1 and schizophrenia has yet been established. Here, we provide evidence linking the upregulation of SELENBP1 in the PFC of mice with the negative symptoms of schizophrenia. We verified the levels of SELENBP1 transcripts in postmortem PFC brain tissues from patients with schizophrenia and matched healthy controls. We also generated transgenic mice expressing human SELENBP1 (hSELENBP1 Tg) and examined their neuropathological features, intrinsic firing properties of PFC 2/3-layer pyramidal neurons, and frontal cortex (FC) electroencephalographic (EEG) responses to auditory stimuli. Schizophrenia-like behaviors in hSELENBP1 Tg mice and mice expressing Selenbp1 in the FC were assessed. SELENBP1 transcript levels were higher in the brains of patients with schizophrenia than in those of matched healthy controls. The hSELENBP1 Tg mice displayed negative endophenotype behaviors, including heterotopias- and ectopias-like anatomical deformities in upper-layer cortical neurons and social withdrawal, deficits in nesting, and anhedonia-like behavior. Additionally, hSELENBP1 Tg mice exhibited reduced excitabilities of PFC 2/3-layer pyramidal neurons and abnormalities in EEG biomarkers observed in schizophrenia. Furthermore, mice overexpressing Selenbp1 in FC showed deficits in sociability. These results suggest that upregulation of SELENBP1 in the PFC causes asociality, a negative symptom of schizophrenia.


Assuntos
Esquizofrenia , Humanos , Animais , Camundongos , Esquizofrenia/genética , Esquizofrenia/metabolismo , Córtex Pré-Frontal/metabolismo , Células Piramidais/metabolismo , Encéfalo/metabolismo , Camundongos Transgênicos , Proteínas de Ligação a Selênio/genética , Proteínas de Ligação a Selênio/metabolismo
13.
Nano Lett ; 24(19): 5855-5861, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38690800

RESUMO

Quantum dots (QDs) have garnered a significant amount of attention as promising memristive materials owing to their size-dependent tunable bandgap, structural stability, and high level of applicability for neuromorphic computing. Despite these advantageous properties, the development of QD-based memristors has been hindered by challenges in understanding and adjusting the resistive switching (RS) behavior of QDs. Herein, we propose three types of InP/ZnSe/ZnS QD-based memristors to elucidate the RS mechanism, employing a thin poly(methyl methacrylate) layer. This approach not only allows us to identify which carriers (electron or hole) are trapped within the QD layer but also successfully demonstrates QD-based synaptic devices. Furthermore, to utilize the QD memristor as a synapse, long-term potentiation/depression (LTP/LTD) characteristics are measured, resulting in a low nonlinearity of LTP/LTD at 0.1/1. On the basis of the LTP/LTD characteristics, single-layer perceptron simulations were performed using the Extended Modified National Institute of Standards and Technology, verifying a maximum recognition rate of 91.46%.

14.
J Am Chem Soc ; 146(33): 23067-23074, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39134028

RESUMO

A new class of Ru-sulfonamidate precatalysts for sp3 C-H hydroxylation is described along with a versatile process for assembling unique heteroleptic Ru(II) complexes. The latter has enabled structure-performance studies to identify an optimal precatalyst, 2h, bearing one 4,4'-di-tert-butylbipyridine (dtbpy) and one pyridylsulfonamidate ligand. Single-crystal X-ray analysis confirmed the structure and stereochemistry of this adduct. Catalytic hydroxylation reactions are conveniently performed in an aqueous, biphasic solvent mixture with 1 mol % 2h and ceric ammonium nitrate as the terminal oxidant and deliver oxidized products in yields ranging from 37 to 90%. A comparative mechanistic investigation of 2h against a related homoleptic precatalyst, [Ru(dtbpy)2(MeCN)2](OTf)2, convincingly establishes that the former generates one or more surprisingly long-lived active species under the reaction conditions, thus accounting for the high turnover numbers. Structure-performance, kinetics, mass spectrometric, and electrochemical analyses reveal that ligand oxidation is a prerequisite for catalyst activation. Our findings sharply contrast a large body of prior art showing that ligand oxidation is detrimental to catalyst function. We expect these results to stimulate future innovations in C-H oxidation research.

15.
J Am Chem Soc ; 146(5): 3521-3530, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38284769

RESUMO

Copper-catalyzed aerobic oxidative coupling of diaryl imines provides a route for conversion of ammonia to hydrazine. The present study uses experimental and density functional theory computational methods to investigate the mechanism of N-N bond formation, and the data support a mechanism involving bimolecular coupling of Cu-coordinated iminyl radicals. Computational analysis is extended to CuII-mediated C-C, N-N, and O-O coupling reactions involved in the formation of cyanogen (NC-CN) from HCN, 1,3-butadiyne from ethyne (i.e., Glaser coupling), hydrazine from ammonia, and hydrogen peroxide from water. The results reveal two different mechanistic pathways. Heteroatom ligands with an uncoordinated lone pair (iminyl, NH2, OH) undergo charge transfer to CuII, generating ligand-centered radicals that undergo facile bimolecular radical-radical coupling. Ligands lacking a lone pair (CN and CCH) form bridged binuclear diamond-core structures that undergo C-C coupling. This mechanistic bifurcation is rationalized by analysis of spin densities in key intermediates and transition states, as well as multiconfigurational calculations. Radical-radical coupling is especially favorable for N-N coupling owing to energetically favorable charge transfer in the intermediate and thermodynamically favorable product formation.

16.
Emerg Infect Dis ; 30(5): 991-994, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38666642

RESUMO

African swine fever virus (ASFV) genotype II is endemic to Vietnam. We detected recombinant ASFV genotypes I and II (rASFV I/II) strains in domestic pigs from 6 northern provinces in Vietnam. The introduction of rASFV I/II strains could complicate ongoing ASFV control measures in the region.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Genótipo , Filogenia , Animais , Vírus da Febre Suína Africana/genética , Vírus da Febre Suína Africana/classificação , Vietnã/epidemiologia , Febre Suína Africana/epidemiologia , Febre Suína Africana/virologia , Suínos , Sus scrofa/virologia , Recombinação Genética
17.
HIV Med ; 25(3): 381-390, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38147871

RESUMO

OBJECTIVES: Cabotegravir + rilpivirine (CAB + RPV) dosed monthly or every 2 months is the first complete long-acting (LA) regimen recommended by treatment guidelines for the maintenance of HIV-1 virological suppression. This post hoc analysis summarizes outcomes for Asian participants through week 96. METHODS: Data from Asian participants naive to CAB + RPV randomized to receive dosing every 4 weeks (Q4W) or every 8 weeks (Q8W) in the FLAIR (NCT02938520) and ATLAS-2M (NCT03299049) phase 3/3b studies were pooled. The proportion of participants with plasma HIV-1 RNA ≥50 and <50 copies/mL (per FDA Snapshot algorithm), incidence of confirmed virological failure (CVF; two consecutive HIV-1 RNA ≥200 copies/mL), pharmacokinetics, safety, and tolerability through week 96 were assessed. RESULTS: Overall, 41 Asian participants received CAB + RPV (Q8W, n = 17; Q4W, n = 24). At week 96, 83% (n = 34/41) of participants maintained HIV-1 RNA <50 copies/mL, none had HIV-1 RNA ≥50 copies/mL, and 17% (n = 7/41) had no virological data. No Asian participant met the CVF criterion. Drug-related adverse events occurred in 44% (n = 18/41) of participants; none were Grade ≥3. All injection site reactions were Grade 1 or 2; median duration was 2 days and most resolved within 7 days (90%, n = 390/435). CAB and RPV trough concentrations remained well above their respective protein-adjusted 90% inhibitory concentrations (CAB, 0.166 µg/mL; RPV, 12 ng/mL) through week 96. CONCLUSIONS: CAB + RPV LA demonstrated high efficacy, with no participants having CVF, and an acceptable safety profile in Asian participants through week 96. These data support CAB + RPV LA as a complete regimen for the maintenance of HIV-1 virological suppression in Asian individuals.


Assuntos
Fármacos Anti-HIV , Dicetopiperazinas , Infecções por HIV , Soropositividade para HIV , Piridonas , Humanos , Fármacos Anti-HIV/efeitos adversos , Infecções por HIV/tratamento farmacológico , Soropositividade para HIV/tratamento farmacológico , Rilpivirina , RNA Viral , Ensaios Clínicos Fase III como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
18.
New Phytol ; 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39155726

RESUMO

Arabidopsis PSEUDORESPONSE REGULATOR7 (PRR7) is a core component of the circadian oscillator which also plays a crucial role in freezing tolerance. PRR7 undergoes proteasome-dependent degradation to discretely phase maximal expression in early evening. While its repressive activity on downstream genes is integral to cold regulation, the mechanism of the conditional regulation of the PRR7 abundance is unknown. We used mutant analysis, protein interaction and ubiquitylation assays to establish that the ubiquitin ligase adaptor, HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENE 15 (HOS15), controls the protein accumulation pattern of PRR7 through direct protein-protein interactions at low temperatures. Freezing tolerance and electrolyte leakage assays show that PRR7 enhances cold temperature sensitivity, supported by ChIP-qPCR at C-REPEAT BINDING FACTOR1 (CBF1) and COLD-REGULATED 15A (COR15A) promoters where PRR7 levels were higher in hos15 mutants. HOS15 mediates PRR7 turnover through enhanced ubiquitylation at low temperature in the dark. Under the same conditions, increased PRR7 association with the promoters of CBFs and COR15A in hos15 correlates with decreased CBF1 and COR15A transcription and enhanced freezing sensitivity. We propose a novel mechanism whereby HOS15-mediated degradation of PRR7 provides an intersection between the circadian system and other cold acclimation pathways that lead to increased freezing tolerance.

19.
Cytokine ; 178: 156579, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38471419

RESUMO

The aim of this study was to evaluate the effect of non-surgical periodontal treatment in the expression of chemokine receptors, in individuals with Periodontitis, associated or not with Diabetes. Pilot study, which included patients (n = 45) with Periodontitis, associated (n = 25) or not (n = 20) with Diabetes, submitted to the non-surgical periodontal treatment for one month. The expression of chemokine receptors CCR2, CCR5, and CX3CR1 at the mRNA level was evaluated in the peripheral mononuclear cells, as well as the expression of these receptors at the protein level was verified in monocyte subtypes (classical, intermediate, and non-classical monocytes). There was higher expression of CCR2 and CCR5 receptors at the initial visit in the group with Diabetes, with no differences for CX3CR1 (p = 0.002; p = 0.018, and p = 0.896, respectively), without differences after treatment. There was higher expression of CCR2 and CCR5 proteins in the group with Diabetes at the initial visit for classical, intermediate, and nonclassical monocytes, with no differences for CX3CR1 (CCR2: p = 0.004; p = 0.026; p = 0.024; CCR5: 0.045; p = 0.045; p = 0.013; CX3CR1: p = 0.424; p = 0.944; p = 0.392, respectively), without differences after the end of treatment. Concerning each group separately, there were reductions in the expression of CCR2 as well as CCR5 in classical, intermediate, and nonclassical monocytes, and reduction of CX3CR1 in classical monocytes after treatment in the group with Diabetes (p = 0.003; p = 0.006; p = 0.039; p = 0.007; p = 0.006; p = 0.004; p = 0.019, respectively), without differences in the group without Diabetes. The expression of the chemokine receptors CCR2 and CCR5, in patients with Periodontitis associated with Diabetes, is favorably modified after the end of the non-surgical periodontal treatment.


Assuntos
Diabetes Mellitus , Periodontite , Humanos , Monócitos/metabolismo , Projetos Piloto , Receptores CCR2/genética , Receptores CCR2/metabolismo , Receptores CCR5/genética , Receptores CCR5/metabolismo , Diabetes Mellitus/metabolismo , Periodontite/terapia , Periodontite/metabolismo , Receptor 1 de Quimiocina CX3C/genética , Receptor 1 de Quimiocina CX3C/metabolismo
20.
Gastrointest Endosc ; 100(2): 231-239.e2, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38521476

RESUMO

BACKGROUND AND AIMS: EUS-guided FNA and biopsy (EUS-FNAB) is a standard diagnostic procedure for pancreatic masses but not gallbladder (GB) cancer (GBC). The aim of this study was to investigate the efficacy and safety of EUS-FNAB for patients with suspected GBC. METHODS: Data were analyzed from patients who underwent EUS-FNAB for suspected GBC in 3 hospitals between 2010 and 2023. The diagnostic performance and safety of EUS-FNAB according to characteristic factors were calculated and compared. RESULTS: Of 170 patients, 163 had GBC. EUS-FNAB samples were obtained from the GB in 125 patients and sites other than the GB in 45 patients. The overall sensitivity, specificity, and accuracy were 83.4%, 100%, and 84.1%, respectively. The sensitivity and accuracy for patients with GB samples were 80.8% and 81.6%; for patients without GB samples, these values were 90.7% and 91.1%. The sensitivity and accuracy were higher with fine-needle biopsy needles than with FNA needles and with ≤22-gauge needles than with 25-gauge needles. However, no significant differences were observed between the GB and lymph node samples. GB lesions <40 mm in size, wall-thickening type, fundal location, absence of extensive liver invasion, and distant metastasis were more frequent in patients without GB samples than in patients with GB samples. Four mild bleeding events were the only reported adverse events. CONCLUSIONS: EUS-FNAB was safe and showed high diagnostic performance for patients with suspected GBC, regardless of the target site. When appropriate GB targeting is difficult, targeting the lymph nodes would be a good strategy with comparable outcomes.


Assuntos
Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico , Neoplasias da Vesícula Biliar , Sensibilidade e Especificidade , Humanos , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/diagnóstico , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Adulto , Idoso de 80 Anos ou mais , Linfonodos/patologia , Linfonodos/diagnóstico por imagem , Agulhas , Vesícula Biliar/patologia
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