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1.
Nat Immunol ; 21(2): 199-209, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31959979

RESUMO

A goal of HIV vaccine development is to elicit antibodies with neutralizing breadth. Broadly neutralizing antibodies (bNAbs) to HIV often have unusual sequences with long heavy-chain complementarity-determining region loops, high somatic mutation rates and polyreactivity. A subset of HIV-infected individuals develops such antibodies, but it is unclear whether this reflects systematic differences in their antibody repertoires or is a consequence of rare stochastic events involving individual clones. We sequenced antibody heavy-chain repertoires in a large cohort of HIV-infected individuals with bNAb responses or no neutralization breadth and uninfected controls, identifying consistent features of bNAb repertoires, encompassing thousands of B cell clones per individual, with correlated T cell phenotypes. These repertoire features were not observed during chronic cytomegalovirus infection in an independent cohort. Our data indicate that the development of numerous B cell lineages with antibody features associated with autoreactivity may be a key aspect in the development of HIV neutralizing antibody breadth.


Assuntos
Vacinas contra a AIDS/imunologia , Linfócitos B/imunologia , Anticorpos Amplamente Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/imunologia
2.
Cell ; 165(2): 449-63, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-26949186

RESUMO

Antibodies with ontogenies from VH1-2 or VH1-46-germline genes dominate the broadly neutralizing response against the CD4-binding site (CD4bs) on HIV-1. Here, we define with longitudinal sampling from time-of-infection the development of a VH1-46-derived antibody lineage that matured to neutralize 90% of HIV-1 isolates. Structures of lineage antibodies CH235 (week 41 from time-of-infection, 18% breadth), CH235.9 (week 152, 77%), and CH235.12 (week 323, 90%) demonstrated the maturing epitope to focus on the conformationally invariant portion of the CD4bs. Similarities between CH235 lineage and five unrelated CD4bs lineages in epitope focusing, length-of-time to develop breadth, and extraordinary level of somatic hypermutation suggested commonalities in maturation among all CD4bs antibodies. Fortunately, the required CH235-lineage hypermutation appeared substantially guided by the intrinsic mutability of the VH1-46 gene, which closely resembled VH1-2. We integrated our CH235-lineage findings with a second broadly neutralizing lineage and HIV-1 co-evolution to suggest a vaccination strategy for inducing both lineages.


Assuntos
Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Infecções por HIV/imunologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/química , Linfócitos B/imunologia , Anticorpos Anti-HIV/química , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Alinhamento de Sequência
3.
Cell ; 161(5): 1026-1034, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25959776

RESUMO

Vaccines for rapidly evolving pathogens will confer lasting immunity if they elicit antibodies recognizing conserved epitopes, such as a receptor-binding site (RBS). From characteristics of an influenza-virus RBS-directed antibody, we devised a signature motif to search for similar antibodies. We identified, from three vaccinees, over 100 candidates encoded by 11 different VH genes. Crystal structures show that antibodies in this class engage the hemagglutinin RBS and mimic binding of the receptor, sialic acid, by supplying a critical dipeptide on their projecting, heavy-chain third complementarity determining region. They share contacts with conserved, receptor-binding residues but contact different residues on the RBS periphery, limiting the likelihood of viral escape when several such antibodies are present. These data show that related modes of RBS recognition can arise from different germline origins and mature through diverse affinity maturation pathways. Immunogens focused on an RBS-directed response will thus have a broad range of B cell targets.


Assuntos
Anticorpos Antivirais/química , Receptores Virais/química , Sequência de Aminoácidos , Anticorpos Antivirais/imunologia , Regiões Determinantes de Complementaridade , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Vacinas contra Influenza/imunologia , Modelos Moleculares , Mimetismo Molecular , Dados de Sequência Molecular
4.
Cell ; 158(3): 481-91, 2014 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25065977

RESUMO

Development of strategies for induction of HIV-1 broadly neutralizing antibodies (bnAbs) by vaccines is a priority. Determining the steps of bnAb induction in HIV-1-infected individuals who make bnAbs is a key strategy for immunogen design. Here, we study the B cell response in a bnAb-producing individual and report cooperation between two B cell lineages to drive bnAb development. We isolated a virus-neutralizing antibody lineage that targeted an envelope region (loop D) and selected virus escape mutants that resulted in both enhanced bnAb lineage envelope binding and escape mutant neutralization-traits associated with increased B cell antigen drive. Thus, in this individual, two B cell lineages cooperated to induce the development of bnAbs. Design of vaccine immunogens that simultaneously drive both helper and broadly neutralizing B cell lineages may be important for vaccine-induced recapitulation of events that transpire during the maturation of neutralizing antibodies in HIV-1-infected individuals.


Assuntos
Vacinas contra a AIDS/química , Vacinas contra a AIDS/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/fisiologia , Sequência de Aminoácidos , Linfócitos B/imunologia , Evasão da Resposta Imune , Modelos Moleculares , Dados de Sequência Molecular , Mutação , Alinhamento de Sequência , Produtos do Gene env do Vírus da Imunodeficiência Humana/genética , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia
5.
Exp Cell Res ; 438(2): 114039, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38641125

RESUMO

The pathogenesis of acute lung injury is not fully understood. Stimulator of interferon genes (STING) and ferroptosis have been implicated in various pathological and physiological processes, including acute lung injury (ALI). However, the relationship between STING and ferroptosis in lipopolysaccharide (LPS)-induced ALI is unclear. We found that LPS stimulation activated STING and ferroptosis. Furthermore, STING knockout and ferroptosis inhibitor alleviated lung inflammation and epithelial cell damage. Also, STING knockout reduced inflammation injury and ferroptosis. Notably, the ferroptosis inducer reversed the alleviation of inflammation caused by STING knockout. These results show that STING participates in the inflammation injury of ALI by regulating ferroptosis. Results also showed that p-STAT3 levels increased after STING knockout, suggesting that STING negatively regulates STAT3 activation. Besides, STAT3 inhibitor aggravated ferroptosis after STING knockout, indicating that STING regulates ferroptosis through STAT3 signaling. In conclusion, STING mediates LPS-induced ALI by regulating ferroptosis, indicating that STING and ferroptosis may be new targets for ALI treatment.


Assuntos
Lesão Pulmonar Aguda , Ferroptose , Lipopolissacarídeos , Proteínas de Membrana , Fator de Transcrição STAT3 , Animais , Humanos , Masculino , Camundongos , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Inflamação/metabolismo , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética
6.
BMC Cancer ; 24(1): 914, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39080568

RESUMO

BACKGROUND: Although there is a strong correlation between the novel cholesterol-to-lymphocyte ratio (CLR) and tumor survival, its prognostic significance in breast cancer (BC) is unknown. After analyzing the relationship between CLR and the overall survival (OS) of patients with BC, we created a predictive model. METHODS: Following retrospective enrollment, 1316 patients with BC were randomized into two cohorts: validation (n = 392) and training (n = 924). Distinct factors within the training dataset were identified for OS by univariate and multivariate Cox analyses; two-tailed P-value < 0.05 were considered to indicate statistical significance. On this premise, we developed novel signals for survival prediction and utilized the calibration curve, receiver operating characteristic curves, and concordance index (C-index) to validate their efficacy across both datasets. RESULTS: Patients with BC were categorized into two categories with differing prognoses based on the CLR score [hazard ratio = 0.492; 95% confidence interval (CI): 0.286-0.846, P = 0.009]. A prediction nomogram was created based on multivariate analysis, which showed that N stage, postoperative pathological categorization, and CLR score were all independently correlated with OS. In the training [C-index = 0.831 (95% CI: 0.788-0.874)] and validation [C-index = 0.775 (95% CI: 0.694-0.856)] cohorts, the nomogram demonstrated favorable performance in predicting OS. In both the training and validation cohorts, it outperformed the traditional staging system [C-index = 0.702 (95% CI: 0.623-0.782)] and [C-index = 0.709 (95% CI: 0.570-0.847)]. The accurate prediction by the signature was further demonstrated by the time-dependent receiver operating characteristic curves. CONCLUSIONS: The novel immunonutritional marker CLR could function as a simplified, cost-effective, easily accessible, non-invasive, and readily promotive prognostic indicator for patients with early-stage BC and demonstrates superior predictive power than the traditional staging system.


Assuntos
Neoplasias da Mama , Colesterol , Linfócitos , Nomogramas , Humanos , Feminino , Neoplasias da Mama/patologia , Neoplasias da Mama/sangue , Neoplasias da Mama/imunologia , Neoplasias da Mama/mortalidade , Prognóstico , Pessoa de Meia-Idade , Colesterol/sangue , Estudos Retrospectivos , Adulto , Idoso , Curva ROC , Biomarcadores Tumorais/sangue , Contagem de Linfócitos , Estadiamento de Neoplasias
7.
BMC Cancer ; 24(1): 762, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918690

RESUMO

BACKGROUND: Despite evidence supporting the high correlation of the novel platelet-to-albumin ratio (PAR) with survival in diverse malignancies, its prognostic relevance in nasopharyngeal carcinoma (NPC) remains underexplored. This study aimed to examine the link between PAR and overall survival (OS) in NPC and to establish a predictive model based on this biomarker. METHODS: We retrospectively assembled a cohort consisting of 858 NPC patients who underwent concurrent chemoradiotherapy (CCRT). Utilizing the maximally selected log-rank method, we ascertained the optimal cut-off point for the PAR. Subsequently, univariate and multivariate Cox proportional hazards models were employed to discern factors significantly associated with OS and to construct a predictive nomogram. Further, we subjected the nomogram's predictive accuracy to rigorous independent validation. RESULTS: The discriminative optimal PAR threshold was determined to be 4.47, effectively stratifying NPC patients into two prognostically distinct subgroups (hazard ratio [HR] = 0.53; 95% confidence interval [CI]: 0.28-0.98, P = 0.042). A predictive nomogram was formulated using the results from multivariate analysis, which revealed age greater than 45 years, T stage, N stage, and PAR score as independent predictors of OS. The nomogram demonstrated a commendable predictive capability for OS, with a C-index of 0.69 (95% CI: 0.64-0.75), surpassing the performance of the conventional staging system, which had a C-index of 0.56 (95% CI: 0.65-0.74). CONCLUSIONS: In the context of NPC patients undergoing CCRT, the novel nutritional-inflammatory biomarker PAR emerges as a promising, cost-efficient, easily accessible, non-invasive, and potentially valuable predictor of prognosis. The predictive efficacy of the nomogram incorporating the PAR score exceeded that of the conventional staging approach, thereby indicating its potential as an enhanced prognostic tool in this clinical setting.


Assuntos
Quimiorradioterapia , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Nomogramas , Humanos , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/terapia , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/sangue , Carcinoma Nasofaríngeo/patologia , Quimiorradioterapia/métodos , Prognóstico , Neoplasias Nasofaríngeas/terapia , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/patologia , Adulto , Plaquetas/patologia , Idoso , Albumina Sérica/análise , Estadiamento de Neoplasias , Adulto Jovem , Modelos de Riscos Proporcionais , Contagem de Plaquetas , Biomarcadores Tumorais/sangue
8.
Inorg Chem ; 63(27): 12624-12634, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38910548

RESUMO

Four Ag(I) complexes with mefenamato and nitrogen heterocyclic ligands, [Ag(2-apy)(mef)]2 (1), [Ag(3-apy)(mef)] (2), [Ag2(tmpyz)(mef)2] (3), and {[Ag(4,4'-bipy)(mef)]2(CH3CN)1.5(H2O)2}n (4), (mef = mefenamato, 2-apy = 2-aminopyridine, 3-apy = 3-aminopyridine, tmpyz = 2,3,5,6-tetramethylpyrazine, 4,4'-bipy = 4,4'-bipyridine), were synthesized and characterized. The interactions of these complexes with BSA were investigated by fluorescence spectroscopy, which indicated that these complexes quench the fluorescence of BSA by a static mechanism. The fluorescence data also indicated that the complexes showed good affinity for BSA, and one binding site on BSA was suitable for the complexes. The in vitro cytotoxicity of the four complexes against human cancer cell lines (MCF-7, HepG-2, A549, and MDA-MB-468) and one normal cell line (HTR-8) was evaluated by the MTT assay. Complex 1 displayed high cytotoxic activity against A549 cells. Further studies revealed that complex 1 could enhance the intracellular levels of ROS (reactive oxygen species) in A549 cells, cause cell cycle arrest in the G0/G1 phase, and induce apoptosis in A549 cells in a dose-dependent manner.


Assuntos
Antineoplásicos , Complexos de Coordenação , Ensaios de Seleção de Medicamentos Antitumorais , Ácido Mefenâmico , Prata , Humanos , Prata/química , Prata/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Ligantes , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Ácido Mefenâmico/farmacologia , Ácido Mefenâmico/química , Apoptose/efeitos dos fármacos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Proliferação de Células/efeitos dos fármacos , Nitrogênio/química , Estrutura Molecular , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Linhagem Celular Tumoral
9.
BMC Gastroenterol ; 24(1): 358, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39390428

RESUMO

BACKGROUND: The Global Leadership Initiative on Malnutrition criteria (GLIM) was established to build a global consensus on the diagnostic criteria for malnutrition. The study aimed to assess the prevalence of the malnutrition diagnosed by GLIM criteria for patients with hepatocellular carcinoma (HCC), and to determine the role of the reduced muscle mass defined by CT scans in the GLIM criteria. METHODS: This cohort research was conducted on adult cirrhotic patients with HCC. The risk of malnutrition was screened by Nutritional Risk Screening 2002 (NRS-2002), and malnutrition was diagnosed by GLIM criteria. The third lumbar vertebrae (L3-SMI) were used to represent the muscle mass in GLIM criteria. The variables associated with overall mortality were assessed by multivariate Cox regression analyses. RESULTS: The incidence of malnutrition diagnosed by GLIM criteria was 49.7% (179/360) in patients with HCC. If reduced muscle mass was not included in GLIM criteria, the prevalence of malnutrition was 31.7% (114/360). GLIM-defined malnutrition (HR = 1.979, 95%CI 1.019-3.841, P = 0.044) was independently associated with overall mortality in patients with HCC. However, the GLIM-defined malnutrition (without muscle mass) was not associated with overall mortality (HR = 0.863, 95%CI 0.399-1.867, P = 0.709). CONCLUSIONS: Skeletal muscle mass is an integral component of the GLIM criteria for patients with HCC. The malnutrition is common in patients with HCC, and malnourishment is associated with higher overall mortality. GLIM criteria are recommended to assess the nutritional status of hospitalized patients with HCC, which is recommended and can be used as the basis for nutritional interventions.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Desnutrição , Tomografia Computadorizada por Raios X , Humanos , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/diagnóstico , Desnutrição/diagnóstico , Desnutrição/epidemiologia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Prevalência , Avaliação Nutricional , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Estado Nutricional , Cirrose Hepática/complicações , Músculo Esquelético/patologia , Músculo Esquelético/diagnóstico por imagem
10.
Acta Pharmacol Sin ; 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39060523

RESUMO

Heart failure with preserved ejection fraction (HFpEF) is a complex clinical syndrome with cardiac dysfunction, fluid retention and reduced exercise tolerance as the main manifestations. Current treatment of HFpEF is using combined medications of related comorbidities, there is an urgent need for a modest drug to treat HFpEF. Geniposide (GE), an iridoid glycoside extracted from Gardenia Jasminoides, has shown significant efficacy in the treatment of cardiovascular, digestive and central nervous system disorders. In this study we investigated the therapeutic effects of GE on HFpEF experimental models in vivo and in vitro. HFpEF was induced in mice by feeding with HFD and L-NAME (0.5 g/L) in drinking water for 8 weeks, meanwhile the mice were treated with GE (25, 50 mg/kg) every other day. Cardiac echocardiography and exhaustive exercise were performed, blood pressure was measured at the end of treatment, and heart tissue specimens were collected after the mice were euthanized. We showed that GE administration significantly ameliorated cardiac oxidative stress, inflammation, apoptosis, fibrosis and metabolic disturbances in the hearts of HFpEF mice. We demonstrated that GE promoted the transcriptional activation of Nrf2 by targeting MMP2 to affect upstream SIRT1 and downstream GSK3ß, which in turn alleviated the oxidative stress in the hearts of HFpEF mice. In H9c2 cells and HL-1 cells, we showed that treatment with GE (1 µM) significantly alleviated H2O2-induced oxidative stress through the MMP2/SIRT1/GSK3ß pathway. In summary, GE regulates cardiac oxidative stress via MMP2/SIRT1/GSK3ß pathway and reduces cardiac inflammation, apoptosis, fibrosis and metabolic disorders as well as cardiac dysfunction in HFpEF. GE exerts anti-oxidative stress properties by binding to MMP2, inhibiting ROS generation in HFpEF through the SIRT1/Nrf2 signaling pathway. In addition, GE can also affect the inhibition of the downstream MMP2 target GSK3ß, thereby suppressing the inflammatory and apoptotic responses in HFpEF. Taken together, GE alleviates oxidative stress/apoptosis/fibrosis and metabolic disorders as well as HFpEF through the MMP2/SIRT1/GSK3ß signaling pathway.

11.
Chem Soc Rev ; 52(8): 2596-2616, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-36994760

RESUMO

Molecular structure conversion concomitant with mass transfer processes at the electrode-electrolyte interfaces plays a central role in energy electrochemistry. Mass spectrometry, as one of the most intuitive, sensitive techniques, provides the capability to collect transient intermediates and products and uncover reaction mechanisms and kinetics. In situ time-of-flight secondary ion electrochemical mass spectrometry with inherent high mass and spatiotemporal resolution has emerged as a promising strategy for investigating electrochemical processes at the electrode surface. This review illustrates the recent advancements in coupling time-of-flight secondary ion mass spectrometry and electrochemistry to visualize and quantify local dynamic electrochemical processes, identify solvated species distribution, and disclose hidden reaction pathways at the molecular level. Moreover, the key challenges in this field are further discussed to promote new applications and discoveries in operando studying the dynamic electrochemical interfaces of advanced energy systems.

12.
J Cell Physiol ; 2023 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-37393608

RESUMO

Anthraquinones are polycyclic compounds with an unsaturated diketone structure (quinoid moiety). As important secondary metabolites of plants, anthraquinones play an important role in the response of many biological processes and environmental factors. Anthraquinones are common in the human diet and have a variety of biological activities including anticancer, antibacterial, and antioxidant activities that reduce disease risk. The biological activity of anthraquinones depends on the substitution pattern of their hydroxyl groups on the anthraquinone ring structure. However, there is still a lack of systematic summary on the distribution, classification, and biosynthesis of plant anthraquinones. Therefore, this paper systematically reviews the research progress of the distribution, classification, biosynthesis, and regulation of plant anthraquinones. Additionally, we discuss future opportunities in anthraquinone research, including biotechnology, therapeutic products, and dietary anthraquinones.

13.
Nat Prod Rep ; 40(8): 1303-1353, 2023 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-36454108

RESUMO

Covering: up to 2022Pentacyclic triterpenoids are important natural bioactive substances that are widely present in plants and fungi. They have significant medicinal efficacy, play an important role in reducing blood glucose and protecting the liver, and have anti-inflammatory, anti-oxidation, anti-fatigue, anti-viral, and anti-cancer activities. Pentacyclic triterpenoids are derived from the isoprenoid biosynthetic pathway, which generates common precursors of triterpenes and steroids, followed by cyclization with oxidosqualene cyclases (OSCs) and decoration via cytochrome P450 monooxygenases (CYP450s) and glycosyltransferases (GTs). Many biosynthetic pathways of triterpenoid saponins have been elucidated by studying their metabolic regulation network through the use of multiomics and identifying their functional genes. Unfortunately, natural resources of pentacyclic triterpenoids are limited due to their low content in plant tissues and the long growth cycle of plants. Based on the understanding of their biosynthetic pathway and transcriptional regulation, plant bioreactors and microbial cell factories are emerging as alternative means for the synthesis of desired triterpenoid saponins. The rapid development of synthetic biology, metabolic engineering, and fermentation technology has broadened channels for the accumulation of pentacyclic triterpenoid saponins. In this review, we summarize the classification, distribution, structural characteristics, and bioactivity of pentacyclic triterpenoids. We further discuss the biosynthetic pathways of pentacyclic triterpenoids and involved transcriptional regulation. Moreover, the recent progress and characteristics of heterologous biosynthesis in plants and microbial cell factories are discussed comparatively. Finally, we propose potential strategies to improve the accumulation of triterpenoid saponins, thereby providing a guide for their future biomanufacturing.


Assuntos
Produtos Biológicos , Saponinas , Triterpenos , Triterpenos Pentacíclicos/metabolismo , Produtos Biológicos/metabolismo , Triterpenos/química , Plantas/metabolismo , Saponinas/química
14.
Metab Eng ; 76: 232-246, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36849090

RESUMO

Cholesterol serves as a key precursor for many high-value chemicals such as plant-derived steroidal saponins and steroidal alkaloids, but a plant chassis for effective biosynthesis of high levels of cholesterol has not been established. Plant chassis have significant advantages over microbial chassis in terms of membrane protein expression, precursor supply, product tolerance, and regionalization synthesis. Here, using Agrobacterium tumefaciens-mediated transient expression technology, Nicotiana benthamiana, and a step-by-step screening approach, we identified nine enzymes (SSR1-3, SMO1-3, CPI-5, CYP51G, SMO2-2, C14-R-2, 8,7SI-4, C5-SD1, and 7-DR1-1) from the medicinal plant Paris polyphylla and established detailed biosynthetic routes from cycloartenol to cholesterol. Specfically, we optimized HMGR, a key gene of the mevalonate pathway, and co-expressed it with the PpOSC1 gene to achieve a high level of cycloartenol (28.79 mg/g dry weight, which is a sufficient amount of precursor for cholesterol biosynthesis) synthesis in the leaves of N. benthamiana. Subsequently, using a one-by-one elimination method we found that six of these enzymes (SSR1-3, SMO1-3, CPI-5, CYP51G, SMO2-2, and C5-SD1) were crucial for cholesterol production in N. benthamiana, and we establihed a high-efficiency cholesterol synthesis system with a yield of 5.63 mg/g dry weight. Using this strategy, we also discovered the biosynthetic metabolic network responsible for the synthesis of a common aglycon of steroidal saponin, diosgenin, using cholesterol as a substrate, obtaining a yield of 2.12 mg/g dry weight in N. benthamiana. Our study provides an effective strategy to characterize the metabolic pathways of medicinal plants that lack a system for in vivo functional verification, and also lays a foundation for the synthesis of active steroid saponins in plant chassis.


Assuntos
Diosgenina , Liliaceae , Saponinas , Diosgenina/metabolismo , Liliaceae/química , Liliaceae/metabolismo , Colesterol/genética , Colesterol/metabolismo , Plantas/metabolismo , Saponinas/genética , Saponinas/química
15.
Immunity ; 41(6): 909-18, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25526306

RESUMO

In HIV-1, the ability to mount antibody responses to conserved, neutralizing epitopes is critical for protection. Here we have studied the light chain usage of human and rhesus macaque antibodies targeted to a dominant region of the HIV-1 envelope second variable (V2) region involving lysine (K) 169, the site of immune pressure in the RV144 vaccine efficacy trial. We found that humans and rhesus macaques used orthologous lambda variable gene segments encoding a glutamic acid-aspartic acid (ED) motif for K169 recognition. Structure determination of an unmutated ancestor antibody demonstrated that the V2 binding site was preconfigured for ED motif-mediated recognition prior to maturation. Thus, light chain usage for recognition of the site of immune pressure in the RV144 trial is highly conserved across species. These data indicate that the HIV-1 K169-recognizing ED motif has persisted over the diversification between rhesus macaques and humans, suggesting an evolutionary advantage of this antibody recognition mode.


Assuntos
Vacinas contra a AIDS , Anticorpos Antivirais/metabolismo , Linfócitos B/imunologia , Epitopos de Linfócito B/metabolismo , Proteína gp120 do Envelope de HIV/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Cadeias Leves de Imunoglobulina/metabolismo , Sequência de Aminoácidos , Animais , Afinidade de Anticorpos/genética , Células Cultivadas , Ensaios Clínicos como Assunto , Sequência Conservada/genética , Mapeamento de Epitopos , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/prevenção & controle , Humanos , Macaca mulatta , Dados de Sequência Molecular , Mutação/genética , Filogenia , Ligação Proteica/genética , Engenharia de Proteínas
16.
Environ Sci Technol ; 57(48): 19295-19303, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37938123

RESUMO

N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6-PPD), one of the most common additives used in rubber, enters the environment due to significant emissions of tire wear particles. 6-PPD quinone (6-PPDQ) is an important derivative of 6-PPD after ozonization. With concentrations ranging from nanograms per liter to µg/L, 6-PPDQ has so far been identified in a series of water samples. Acute lethality of 6-PPDQ in coho salmon (LC50 < 1 µg/L) was lower than environmental concentrations of 6-PPDQ, highlighting the environment exposure risks of 6-PPDQ. It is becoming increasingly necessary to investigate the potential toxicity of 6-PPDQ at environmental concentrations. Here, we examined the effect of 6-PPDQ exposure on lifespan and healthspan and the underlying mechanism in Caenorhabditis elegans. Exposure to 6-PPDQ (1 and 10 µg/L) shortened the lifespan. Meanwhile, during the aging process, 6-PPDQ (0.1-10 µg/L) could decrease both pumping rate and locomotion behavior, suggesting the 6-PPDQ toxicity on healthspan. For the underlying molecular mechanism, the dysregulation in the insulin signaling pathway was linked to toxicity of 6-PPDQ on lifespan and healthspan. In the insulin signaling pathway, DAF-2 restricted the function of DAF-16 to activate downstream targets (SOD-3 and HSP-6), which in turn controlled the toxicity of 6-PPDQ on lifespan and healthspan. Additionally, in response to 6-PPDQ toxicity, insulin peptides (INS-6, INS-7, and DAF-28) could activate the corresponding receptor DAF-2. Therefore, exposure to 6-PPDQ at environmentally relevant concentrations potentially causes damage to both lifespan and healthspan by activating insulin signaling in organisms.


Assuntos
Benzoquinonas , Caenorhabditis elegans , Exposição Ambiental , Insulina , Longevidade , Fenilenodiaminas , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , Insulina/metabolismo , Longevidade/efeitos dos fármacos , Fenilenodiaminas/toxicidade , Benzoquinonas/toxicidade , Receptor de Insulina/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
Environ Sci Technol ; 57(12): 4940-4950, 2023 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-36913653

RESUMO

6-PPD quinone (6-PPDQ) can be transformed from 6-PPD through ozonation. Nevertheless, the potential neurotoxicity of 6-PPDQ after long-term exposure and the underlying mechanism are largely unclear. In Caenorhabditis elegans, we here observed that 0.1-10 µg/L of 6-PPDQ caused several forms of abnormal locomotion behaviors. Meanwhile, the neurodegeneration of D-type motor neurons was observed in 10 µg/L of 6-PPDQ-exposed nematodes. The observed neurodegeneration was associated with the activation of the Ca2+ channel DEG-3-mediated signaling cascade. In this signaling cascade, expressions of deg-3, unc-68, itr-1, crt-1, clp-1, and tra-3 were increased by 10 µg/L of 6-PPDQ. Moreover, among genes encoding neuronal signals required for the control of stress response, expressions of jnk-1 and dbl-1 were decreased by 0.1-10 µg/L of 6-PPDQ, and expressions of daf-7 and glb-10 were decreased by 10 µg/L of 6-PPDQ. RNAi of jnk-1, dbl-1, daf-7, and glb-10 resulted in the susceptibility to 6-PPDQ toxicity in decreasing locomotory ability and in inducing neurodegeneration, suggesting that JNK-1, DBL-1, DAF-7, and GLB-10 were also required for the induction of 6-PPDQ neurotoxicity. Molecular docking analysis further demonstrated the binding potential of 6-PPDQ to DEG-3, JNK-1, DBL-1, DAF-7, and GLB-10. Together, our data suggested the exposure risk of 6-PPDQ at environmentally relevant concentrations in causing neurotoxicity in organisms.


Assuntos
Benzoquinonas , Caenorhabditis elegans , Locomoção , Neurônios Motores , Fenilenodiaminas , Animais , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Locomoção/efeitos dos fármacos , Simulação de Acoplamento Molecular , Fenilenodiaminas/toxicidade , Benzoquinonas/toxicidade , Neurônios Motores/efeitos dos fármacos
18.
Crit Care ; 27(1): 173, 2023 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-37147701

RESUMO

BACKGROUND: This study aims to provide an updated assessment of the efficacy of optimized enteral nutrition (EN) delivery by implementing the volume-based feeding (VBF) protocol in critically ill patients. METHODS: We updated our previous literature retrieval with no language restrictions. The inclusion criteria were:1) Participants: Critically ill patients (Patients who was admitted in ICU; 2) Intervention: The VBF protocol was adopted for EN administration; 3) Comparison: The rate-based feeding (RBF) protocol was adopted for EN administration; 4) Major outcomes: EN nutrition delivery. The exclusion criteria included participants aged < 18 years, duplicated literature, animal and cellular experiments, and studies lacking any of the outcomes mentioned in the inclusion criteria. The databases included MEDLINE (through PubMed), Web of Science, Cochrane Library, Chinese Biomedical Literature Service System (SinoMed), Wanfang Data Knowledge Service Platform, and China National Knowledge Infrastructure. RESULT: Sixteen studies involving a total of 2896 critically ill patients are included in the updated meta-analysis. Compared with the previous meta-analysis, nine new studies were added that included 2205 more patients. The VBF protocol significantly improved energy (MD = 15.41%, 95% CI: [10.68, 20.14], p < 0.00001) and protein (MD = 22.05%, 95% CI: [10.89, 33.22], p = 0.0001) delivery. The patients in the VBF group stayed in the ICU for a shorter time (MD = 0.78, 95% CI: [0.01, 1.56], p = 0.05). The VBF protocol did not increase the risk of death (RR = 1.03, 95% CI: [0.85, 1.24], p = 0.76) or prolong the mechanical ventilation duration (MD = 0.81, 95% CI: [-0.30,1.92], p = 0.15). In addition, the VBF protocol did not affect EN complications, such as diarrhea (RR = 0.91, 95% CI: [0.73, 1.15], p = 0.43), emesis (RR = 1.23, 95% CI: [0.76, 1.99], p = 0.41), feeding intolerance (RR = 1.14, 95% CI: [0.63, 2.09], p = 0.66), and gastric retention (RR = 0.45, 95% CI: [0.16, 1.30], p = 0.14). CONCLUSION: Our study revealed that the VBF protocol significantly improved calorie and protein delivery in critically ill patients with no additional risk.


Assuntos
Estado Terminal , Nutrição Enteral , Humanos , Nutrição Enteral/métodos , Estado Terminal/terapia , Respiração Artificial , Tempo de Internação , Hospitalização , Unidades de Terapia Intensiva , Metanálise como Assunto
19.
World J Microbiol Biotechnol ; 39(12): 340, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37821760

RESUMO

Fusarium graminearum, a devastating fungal pathogen, is the main pathogen of Fusarium head blight (FHB) in wheat globally; it results in significant yield loss and mycotoxin contamination that severely threatens global wheat production and food safety. However, despite ongoing efforts, controlling this pathogen still remains a major challenge. Surfactin, primarily synthesized by Bacillus sp. via non-ribosomal peptide synthetases, exhibits potent surfactant and antibacterial properties, but its antifungal mechanism has yet to be fully elucidated. We found that the EC50 of surfactin against hyphal growth of F. graminearum was 102.1 µg/mL, and control efficacy against wheat FHB under field conditions achieved 86.38% in wheat cultivar Huaimai 40 and 81.60% in wheat cultivar Zhoumai 36, indicating that surfactin has potential antifungal activity against F. graminearum. Accumulated intracellular ROS, decreased mitochondrial membrane potential (MMP), activated metacaspase activity and condensed chromatin, were induced by surfactin in F. graminearum hyphae, suggesting that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Furthermore, accumulated intracellular ROS was evidenced to act as a key mediator of surfactin-induced apoptosis. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that surfactin induces caspase-independent apoptosis in F. graminearum. Collectively, this study provides evidence that surfactin induces a ROS-mediated mitochondrial apoptosis in F. graminearum hyphae, and may exert its antifungal activity against F. graminearum by activating apoptosis. This study demonstrates the potential of surfactin as an antifungal agent for FHB biocontrol, provides a new perspective on the antifungal mechanism of surfactin against filamentous fungi, and contributes to the application of surfactin-producing microbes in the biocontrol of plant diseases.


Assuntos
Antifúngicos , Fusarium , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Apoptose , Caspases , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia
20.
Zhongguo Zhong Yao Za Zhi ; 48(23): 6442-6456, 2023 Dec.
Artigo em Zh | MEDLINE | ID: mdl-38212002

RESUMO

The present study aimed to investigate the effect of Xianglian Pills(XLP) on lipid metabolism in obese mice and explore the underlying mechanism based on network pharmacology and intestinal flora. Firstly, network pharmacology was used to predict the possible effect of XLP on obesity. Secondly, an obese mouse model induced by a high-fat diet was established to observe changes in mouse body weight, adiposity index, liver and adipose tissue pathology. Lipid profiles, liver and kidney function markers, insulin content, and the expression of recombinant uncoupling protein 1(UCP-1) and PR structural domain protein 16(PRDM16) were measured. The 16S rRNA gene sequencing technology was used to analyze the changes in the intestinal flora. Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis showed that XLP mainly played a role in improving obesity by regulating lipolysis, type 2 diabetes mellitus, and insulin resistance. The results of animal experiments showed that XLP significantly reduced body weight, adiposity, blood lipid levels, and serum insulin levels in obese mice, while enhancing the expression of UCP-1 and PRDM16 in adipose tissue without causing damage to the liver or kidneys. The 16S rRNA gene sequencing results showed that XLP decreased the Firmicutes/Bacteroidetes(F/B) ratio at the phylum level, increased the relative abundance of Akkermansia and Bacteroides at the family and genus levels, and reduced the abundance of Allobaculum. Therefore, XLP can effectively improve lipid metabolism disorders in high-fat diet-induced obese mice, and the mechanism is related to the improvement of brown adipose function, the browning of white fat, the accelerated lipid metabolism, and the improvement of intestinal flora. However, its effect on promoting the conversion of white adipose to brown adipose still needs to be further studied.


Assuntos
Diabetes Mellitus Tipo 2 , Medicamentos de Ervas Chinesas , Dislipidemias , Microbioma Gastrointestinal , Camundongos , Animais , Camundongos Obesos , Dieta Hiperlipídica/efeitos adversos , Farmacologia em Rede , RNA Ribossômico 16S , Diabetes Mellitus Tipo 2/complicações , Obesidade/tratamento farmacológico , Obesidade/genética , Peso Corporal , Lipídeos , Insulina , Fatores de Transcrição , Dislipidemias/tratamento farmacológico , Dislipidemias/genética , Camundongos Endogâmicos C57BL
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