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1.
Cell ; 166(3): 596-608, 2016 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-27453466

RESUMEN

Influenza virus remains a threat because of its ability to evade vaccine-induced immune responses due to antigenic drift. Here, we describe the isolation, evolution, and structure of a broad-spectrum human monoclonal antibody (mAb), MEDI8852, effectively reacting with all influenza A hemagglutinin (HA) subtypes. MEDI8852 uses the heavy-chain VH6-1 gene and has higher potency and breadth when compared to other anti-stem antibodies. MEDI8852 is effective in mice and ferrets with a therapeutic window superior to that of oseltamivir. Crystallographic analysis of Fab alone or in complex with H5 or H7 HA proteins reveals that MEDI8852 binds through a coordinated movement of CDRs to a highly conserved epitope encompassing a hydrophobic groove in the fusion domain and a large portion of the fusion peptide, distinguishing it from other structurally characterized cross-reactive antibodies. The unprecedented breadth and potency of neutralization by MEDI8852 support its development as immunotherapy for influenza virus-infected humans.


Asunto(s)
Alphainfluenzavirus/inmunología , Anticuerpos Monoclonales/inmunología , Anticuerpos Antivirales/inmunología , Especificidad de Anticuerpos , Secuencia de Aminoácidos , Animales , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Monoclonales Humanizados , Anticuerpos Neutralizantes/química , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/aislamiento & purificación , Anticuerpos Antivirales/química , Anticuerpos Antivirales/aislamiento & purificación , Sitios de Unión de Anticuerpos , Cristalografía por Rayos X , Epítopos/inmunología , Hurones , Humanos , Vacunas contra la Influenza , Ratones , Infecciones por Orthomyxoviridae/prevención & control , Conformación Proteica
2.
Proc Natl Acad Sci U S A ; 121(25): e2314036121, 2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38857391

RESUMEN

Permafrost regions contain approximately half of the carbon stored in land ecosystems and have warmed at least twice as much as any other biome. This warming has influenced vegetation activity, leading to changes in plant composition, physiology, and biomass storage in aboveground and belowground components, ultimately impacting ecosystem carbon balance. Yet, little is known about the causes and magnitude of long-term changes in the above- to belowground biomass ratio of plants (η). Here, we analyzed η values using 3,013 plots and 26,337 species-specific measurements across eight sites on the Tibetan Plateau from 1995 to 2021. Our analysis revealed distinct temporal trends in η for three vegetation types: a 17% increase in alpine wetlands, and a decrease of 26% and 48% in alpine meadows and alpine steppes, respectively. These trends were primarily driven by temperature-induced growth preferences rather than shifts in plant species composition. Our findings indicate that in wetter ecosystems, climate warming promotes aboveground plant growth, while in drier ecosystems, such as alpine meadows and alpine steppes, plants allocate more biomass belowground. Furthermore, we observed a threefold strengthening of the warming effect on η over the past 27 y. Soil moisture was found to modulate the sensitivity of η to soil temperature in alpine meadows and alpine steppes, but not in alpine wetlands. Our results contribute to a better understanding of the processes driving the response of biomass distribution to climate warming, which is crucial for predicting the future carbon trajectory of permafrost ecosystems and climate feedback.


Asunto(s)
Biomasa , Ecosistema , Hielos Perennes , Tibet , Humedales , Plantas/metabolismo , Cambio Climático , Temperatura , Ciclo del Carbono , Desarrollo de la Planta/fisiología , Suelo/química , Pradera
3.
PLoS Genet ; 19(9): e1010923, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37676887

RESUMEN

Circular RNAs (circRNAs) have been recognized as critical regulators of skeletal muscle development. Myocyte enhancer factor 2A (MEF2A) is an evolutionarily conserved transcriptional factor that regulates myogenesis. However, it remains unclear whether MEF2A produces functional circRNAs. In this study, we identified two evolutionarily conserved circular MEF2A RNAs (circMEF2As), namely circMEF2A1 and circMEF2A2, in chicken and mouse muscle stem cells. Our findings revealed that circMEF2A1 promotes myogenesis by regulating the miR-30a-3p/PPP3CA/NFATC1 axis, whereas circMEF2A2 facilitates myogenic differentiation by targeting the miR-148a-5p/SLIT3/ROBO2/ß-catenin signaling pathway. Furthermore, in vivo experiments demonstrated that circMEF2As both promote skeletal muscle growth. We also discovered that the linear MEF2A mRNA-derived MEF2A protein binds to its own promoter region, accelerating the transcription of MEF2A and upregulating the expression of both linear MEF2A and circMEF2As, forming a MEF2A autoregulated positive feedback loop. Moreover, circMEF2As positively regulate the expression of linear MEF2A by adsorbing miR-30a-3p and miR-148a-5p, which directly contribute to the MEF2A autoregulated feedback loop. Importantly, we found that mouse circMEF2As are essential for the myogenic differentiation of C2C12 cells. Collectively, our results demonstrated the evolution, function, and underlying mechanisms of circMEF2As in animal myogenesis, which may provide novel insight for both the farm animal meat industry and human medicine.


Asunto(s)
MicroARNs , ARN Circular , Animales , Humanos , Ratones , Diferenciación Celular , Factores de Transcripción MEF2/genética , MicroARNs/genética , Desarrollo de Músculos/genética , ARN Circular/genética
4.
Plant J ; 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38972042

RESUMEN

Nucleotide-binding leucine-rich repeat (NLR) proteins are crucial intracellular immune receptors in plants, responsible for detecting invading pathogens and initiating defense responses. While previous studies on the evolution and function of NLR genes were mainly limited to land plants, the evolutionary trajectory and immune-activating character of NLR genes in algae remain less explored. In this study, genome-wide NLR gene analysis was conducted on 44 chlorophyte species across seven classes and seven charophyte species across five classes. A few but variable number of NLR genes, ranging from one to 20, were identified in five chlorophytes and three charophytes, whereas no NLR gene was identified from the remaining algal genomes. Compared with land plants, algal genomes possess fewer or usually no NLR genes, implying that the expansion of NLR genes in land plants can be attributed to their adaptation to the more complex terrestrial pathogen environments. Through phylogenetic analysis, domain composition analysis, and conserved motifs profiling of the NBS domain, we detected shared and lineage-specific features between NLR genes in algae and land plants, supporting the common origin and continuous evolution of green plant NLR genes. Immune-activation assays revealed that both TNL and RNL proteins from green algae can elicit hypersensitive responses in Nicotiana benthamiana, indicating the molecular basis for immune activation has emerged in the early evolutionary stage of different types of NLR proteins. In summary, the results from this study suggest that NLR proteins may have taken a role as intracellular immune receptors in the common ancestor of green plants.

5.
Plant Physiol ; 194(4): 2101-2116, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-37995372

RESUMEN

The precise timing of flowering plays a pivotal role in ensuring successful plant reproduction and seed production. This process is intricately governed by complex genetic networks that integrate internal and external signals. This study delved into the regulatory function of microRNA397 (miR397) and its target gene LACCASE-15 (OsLAC15) in modulating flowering traits in rice (Oryza sativa). Overexpression of miR397 led to earlier heading dates, decreased number of leaves on the main stem, and accelerated differentiation of the spikelet meristem. Conversely, overexpression of OsLAC15 resulted in delayed flowering and prolonged vegetative growth. Through biochemical and physiological assays, we uncovered that miR397-OsLAC15 had a profound impact on carbohydrate accumulation and photosynthetic assimilation, consequently enhancing the photosynthetic intensity in miR397-overexpressing rice plants. Notably, we identified that OsLAC15 is at least partially localized within the peroxisome organelle, where it regulates the photorespiration pathway. Moreover, we observed that a high CO2 concentration could rescue the late flowering phenotype in OsLAC15-overexpressing plants. These findings shed valuable insights into the regulatory mechanisms of miR397-OsLAC15 in rice flowering and provided potential strategies for developing crop varieties with early flowering and high-yield traits through genetic breeding.


Asunto(s)
Oryza , Oryza/metabolismo , Flores/fisiología , Fitomejoramiento , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Reproducción , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas
6.
J Infect Dis ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38716969

RESUMEN

BACKGROUND: Monoclonal antibodies (mAbs) represent a crucial antiviral strategy for SARS-CoV-2 infection, but it is unclear whether combination mAbs offer a benefit over single-active mAb treatment. Amubarvimab and romlusevimab significantly reduced the risk of hospitalizations or death in the ACTIV-2/A5401 trial. Certain SARS-CoV-2 variants are intrinsically resistant against romlusevimab, leading to only single-active mAb therapy with amubarvimab in these variants. We evaluated virologic outcomes in individuals treated with single- versus dual-active mAbs. METHODS: Participants were non-hospitalized adults at higher risk of clinical progression randomized to amubarvimab plus romlusevimab or placebo. Quantitative SARS-CoV-2 RNA levels and targeted S gene next-generation sequencing was performed on anterior nasal samples. We compared viral load kinetics and resistance emergence between individuals treated with effective single- versus dual-active mAbs depending on the infecting variant. RESULTS: Study participants receiving single- and dual-active mAbs had similar demographics, baseline nasal viral load, symptom score, and symptom duration. Compared to single-active mAb, treatment with dual-active mAbs led to faster viral load decline at study day 3 (p < 0.001) and day 7 (p < 0.01). Treatment-emergent resistance mutations were more likely to be detected after amubarvimab plus romlusevimab treatment than placebo (2.6% vs 0%, P < 0.001), and more frequently detected in the setting of single-active compared to dual-active mAb treatment (7.2% vs 1.1%, p < 0.01). Single-active and dual-active mAb treatment resulted in similar decrease in rates of hospitalizations or death. CONCLUSION: Compared to single-active mAb therapy, dual-active mAbs led to similar clinical outcomes, but significantly faster viral load decline and a lower risk of emergent resistance.

7.
J Biol Chem ; 299(7): 104856, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37230388

RESUMEN

Neuroblastoma (NB) is one of the most common extracranial solid tumors in children. MYCN gene amplification is highly associated with poor prognosis in high-risk NB patients. In non-MYCN-amplified high-risk NB patients, the expression of c-MYC (MYCC) and its target genes is highly elevated. USP28 as a deubiquitinase is known to regulate the stability of MYCC. We show here USP28 also regulates the stability of MYCN. Genetic depletion or pharmacologic inhibition of the deubiquitinase strongly destabilizes MYCN and stops the growth of NB cells that overexpress MYCN. In addition, MYCC could be similarly destabilized in non-MYCN NB cells by compromising USP28 function. Our results strongly suggest USP28 as a therapeutic target for NB with or without MYCN amplification/overexpression.


Asunto(s)
Células-Madre Neurales , Neuroblastoma , Niño , Humanos , Línea Celular Tumoral , Enzimas Desubicuitinizantes/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteína Proto-Oncogénica N-Myc/genética , Proteína Proto-Oncogénica N-Myc/metabolismo , Proteína Proto-Oncogénica N-Myc/uso terapéutico , Células-Madre Neurales/metabolismo , Neuroblastoma/patología , Factores de Transcripción/metabolismo , Ubiquitina Tiolesterasa/metabolismo
8.
Plant J ; 113(5): 1021-1034, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36602036

RESUMEN

Saururus chinensis, an herbaceous magnoliid without perianth, represents a clade of early-diverging angiosperms that have gone through woodiness-herbaceousness transition and pollination obstacles: the characteristic white leaves underneath inflorescence during flowering time are considered a substitute for perianth to attract insect pollinators. Here, using the newly sequenced S. chinensis genome, we revisited the phylogenetic position of magnoliids within mesangiosperms, and recovered a sister relationship for magnoliids and Chloranthales. By considering differentially expressed genes, we identified candidate genes that are involved in the morphogenesis of the white leaves in S. chinensis. Among those genes, we verified - in a transgenic experiment with Arabidopsis - that increasing the expression of the "pseudo-etiolation in light" gene (ScPEL) can inhibit the biosynthesis of chlorophyll. ScPEL is thus likely responsible for the switches between green and white leaves, suggesting that changes in gene expression may underlie the evolution of pollination strategies. Despite being an herbaceous plant, S. chinensis still has vascular cambium and maintains the potential for secondary growth as a woody plant, because the necessary machinery, i.e., the entire gene set involved in lignin biosynthesis, is well preserved. However, similar expression levels of two key genes (CCR and CAD) between the stem and other tissues in the lignin biosynthesis pathway are possibly associated with the herbaceous nature of S. chinensis. In conclusion, the S. chinensis genome provides valuable insights into the adaptive evolution of pollination in Saururaceae and reveals a possible mechanism for the evolution of herbaceousness in magnoliids.


Asunto(s)
Arabidopsis , Magnoliopsida , Saururaceae , Filogenia , Polinización/genética , Lignina , Magnoliopsida/genética
9.
Biochem Biophys Res Commun ; 727: 150313, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38954981

RESUMEN

Sepsis, a life-threatening condition resulting in multiple organ dysfunction, is characterized by a dysregulated immune response to infection. Current treatment options are limited, leading to unsatisfactory outcomes for septic patients. Here, we present a series of studies utilizing compact bone mesenchymal stem cells (CB-MSCs) and their derived paracrine mediators, especially exosome (CB-MSCs-Exo), to treat mice with cecal ligation and puncture-induced sepsis. Our results demonstrate that CB-MSCs treatment significantly improves the survival rate of septic mice by mitigating excessive inflammatory response and attenuating sepsis-induced organ injuries. Furthermore, CB-MSCs-conditioned medium, CB-MSCs secretome (CB-MSCs-Sec), and CB-MSCs-Exo exhibit potent anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated murine macrophage (RAW264.7). Intriguingly, intravenous administration of CB-MSCs-Exo confers superior protection against inflammation and organ damage in septic mice compared to CB-MSCs in certain aspects. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) shotgun proteomic analysis, we identify a range of characterized proteins derived from the paracrine activity of CB-MSCs, involved in critical biological processes such as immunomodulation and apoptosis. Our findings highlight that the paracrine products of CB-MSCs could serve as a promising cell-free therapeutic agent for sepsis.

10.
Biochem Biophys Res Commun ; 691: 149308, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38029542

RESUMEN

This study tried to generate anti-idiotypic antibodies (Ab2s) which mimic Cry2Aa toxin using a phage-display antibody library (2.8 × 107 CFU/mL). The latter was constructed from a mouse immunized with F (ab')2 fragments digested from anti-Cry2Aa polyclonal antibodies. The F (ab')2 fragments and Plutella xylostella (P. xylostella) brush border membrane vesicles (BBMV) were utilized as targets for selection. Eight mouse phage-display single-chain variable fragments (scFvs) were isolated and identified by enzyme-linked immunoassay (ELISA), PCR and DNA sequencing after four rounds of biopanning. Among them, M3 exhibited the highest binding affinity with F (ab')2, while M4 bound the best with the toxin binding region of cadherin of P. xylostella (PxCad-TBR). Both of these two fragments were chosen for prokaryotic expression. The expressed M3 and M4 proteins with molecular weights of 30 kDa were purified. The M4 showed a binding affinity of 29.9 ± 2.4 nM with the PxCad-TBR and resulted in 27.8 ± 4.3 % larvae mortality against P. xylostella. Computer-assisted molecular modeling and docking analysis showed that mouse scFv M4 mimicked some Cry2Aa toxin binding sites when interacting with PxCad-TBR. Therefore, anti-idiotypic antibodies generated by BBMV-based screening could be useful for the development of new bio-insecticides as an alternative to Cry2Aa toxin for pest control.


Asunto(s)
Bacteriófagos , Insecticidas , Lepidópteros , Anticuerpos de Cadena Única , Animales , Ratones , Biblioteca de Genes , Anticuerpos de Cadena Única/química , Endotoxinas/metabolismo , Anticuerpos Antiidiotipos , Biblioteca de Péptidos
11.
Int J Obes (Lond) ; 48(3): 339-345, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37989765

RESUMEN

BACKGROUND: The Energy-Adjusted Dietary Inflammatory Index (E-DII) is related to both body mass index (BMI) and hyperuricemia. However, the association among BMI, hyperuricemia and DII is yet to be fully elucidated. The purpose of this study is to explore the role of BMI in the relationship between E-DII and hyperuricemia in the American population. METHODS: A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2016, with a sample size of 10,571 participants. The study used a weighted logistic regression model and a generalized additive model (GAM) to explore the associations among BMI, hyperuricemia and E-DII. Furthermore, mediation analysis was utilized to illustrate the mediating relationships among these variables. RESULTS: The results of the study indicated that a higher E-DII was related to an increased risk of hyperuricemia. The association between E-DII and hyperuricemia was partially mediated by BMI. CONCLUSIONS: E-DII is associated with hyperuricemia. BMI mediates the relationship between E-DII and hyperuricemia among Americans, which provides crucial information for the prevention of hyperuricemia.


Asunto(s)
Hiperuricemia , Inflamación , Humanos , Encuestas Nutricionales , Índice de Masa Corporal , Inflamación/epidemiología , Inflamación/diagnóstico , Estudios Transversales , Hiperuricemia/epidemiología , Análisis de Mediación , Dieta/efectos adversos
13.
BMC Microbiol ; 24(1): 133, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38643067

RESUMEN

BACKGROUND: This study aimed to investigate the differences in the microbiota composition of serum exosomes from patients with acute and chronic cholecystitis. METHOD: Exosomes were isolated from the serum of cholecystitis patients through centrifugation and identified and characterized using transmission electron microscopy and nano-flow cytometry. Microbiota analysis was performed using 16S rRNA sequencing. RESULTS: Compared to patients with chronic cholecystitis, those with acute cholecystitis exhibited lower richness and diversity. Beta diversity analysis revealed significant differences in the microbiota composition between patients with acute and chronic cholecystitis. The relative abundance of Proteobacteria was significantly higher in exosomes from patients with acute cholecystitis, whereas Actinobacteria, Bacteroidetes, and Firmicutes were significantly more abundant in exosomes from patients with chronic cholecystitis. Furthermore, functional predictions of microbial communities using Tax4Fun analysis revealed significant differences in metabolic pathways such as amino acid metabolism, carbohydrate metabolism, and membrane transport between the two patient groups. CONCLUSIONS: This study confirmed the differences in the microbiota composition within serum exosomes of patients with acute and chronic cholecystitis. Serum exosomes could serve as diagnostic indicators for distinguishing acute and chronic cholecystitis.


Asunto(s)
Colecistitis Aguda , Colecistitis , Exosomas , Microbioma Gastrointestinal , Microbiota , Humanos , ARN Ribosómico 16S/genética , Microbioma Gastrointestinal/genética , Heces/microbiología , Microbiota/genética
14.
Plant Physiol ; 193(1): 840-854, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37325946

RESUMEN

As the harvest season of most fruit is concentrated, fruit maturation manipulation is essential for the fresh fruit industry to prolong sales time. Gibberellin (GA), an important phytohormone necessary for plant growth and development, has also shown a substantial regulatory effect on fruit maturation; however, its regulatory mechanisms remain inconclusive. In this research, preharvest GA3 treatment effectively delayed fruit maturation in several persimmon (Diospyros kaki) cultivars. Among the proteins encoded by differentially expressed genes, 2 transcriptional activators (NAC TRANSCRIPTION FACTOR DkNAC24 and ETHYLENE RESPONSIVE FACTOR DkERF38) and a repressor (MYB-LIKE TRANSCRIPTION FACTOR DkMYB22) were direct regulators of GERANYLGERANYL DIPHOSPHATE SYNTHASE DkGGPS1, LYSINE HISTIDINE TRANSPORTER DkLHT1, and FRUCTOSE-BISPHOSPHATE ALDOLASE DkFBA1, respectively, resulting in the inhibition of carotenoid synthesis, outward transport of an ethylene precursor, and consumption of fructose and glucose. Thus, the present study not only provides a practical method to prolong the persimmon fruit maturation period in various cultivars but also provides insights into the regulatory mechanisms of GA on multiple aspects of fruit quality formation at the transcriptional regulation level.


Asunto(s)
Diospyros , Giberelinas , Giberelinas/farmacología , Giberelinas/metabolismo , Diospyros/genética , Diospyros/metabolismo , Frutas/metabolismo , Etilenos/metabolismo , Factores de Transcripción/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
15.
Plant Cell ; 33(12): 3658-3674, 2021 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-34524462

RESUMEN

Protons (H+) in acidic soils arrest plant growth. However, the mechanisms by which plants optimize their biological processes to diminish the unfavorable effects of H+ stress remain largely unclear. Here, we showed that in the roots of Arabidopsis thaliana, the C2H2-type transcription factor STOP1 in the nucleus was enriched by low pH in a nitrate-independent manner, with the spatial expression pattern of NITRATE TRANSPORTER 1.1 (NRT1.1) established by low pH required the action of STOP1. Additionally, the nrt1.1 and stop1 mutants, as well as the nrt1.1 stop1 double mutant, had a similar hypersensitive phenotype to low pH, indicating that STOP1 and NRT1.1 function in the same pathway for H+ tolerance. Molecular assays revealed that STOP1 directly bound to the promoter of NRT1.1 to activate its transcription in response to low pH, thus upregulating its nitrate uptake. This action improved the nitrogen use efficiency (NUE) of plants and created a favorable rhizospheric pH for root growth by enhancing H+ depletion in the rhizosphere. Consequently, the constitutive expression of NRT1.1 in stop1 mutants abolished the hypersensitive phenotype to low pH. These results demonstrate that STOP1-NRT1.1 is a key module for plants to optimize NUE and ensure better plant growth in acidic media.


Asunto(s)
Proteínas de Transporte de Anión/genética , Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Nitratos/metabolismo , Proteínas de Plantas/genética , Rizosfera , Suelo/química , Factores de Transcripción/genética , Adaptación Fisiológica/genética , Proteínas de Transporte de Anión/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Concentración de Iones de Hidrógeno , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo
16.
Biotechnol Bioeng ; 121(3): 799-822, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38079153

RESUMEN

The chemical modifications (CMs) of protein is an important technique in chemical biology, protein-based therapy, and material science. In recent years, there has been rapid advances in the development of CMs of peptides and proteins, providing new approaches for peptide and protein functionalization, as well as drug discovery. In this review, we highlight the methods for chemically modifying tyrosine (Tyr) residues in different regions, offering a comprehensive exposition of the research content related to Tyr modification. This review summarizes and provides an outlook on Tyr residue modification, aiming to offer readers assistance in the site-selective modification of macromolecules and to facilitate application research in this field.


Asunto(s)
Péptidos , Tirosina , Péptidos/química
17.
Nitric Oxide ; 145: 1-7, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38309328

RESUMEN

Nitric oxide (NO), as a vital cellular signalling molecule in physiological processes, has been found to play an important role in various biological functions. In this study, we rationally designed three NO donors by tethering nitrobenzene derivatives to three fluorescent chromophores. NX-NO was found to release NO and exhibit a high fluorescence turn-on signal ratio upon exposure to LED yellow light. Additionally, it had excellent photo-stability and good inhibitory activity against cancer cell proliferation, and was successfully applied to cell imaging. Moreover, we detected the release of NO and fluorescence response in the blood of a mouse, suggesting its potential therapeutic application in living organisms.


Asunto(s)
Colorantes Fluorescentes , Donantes de Óxido Nítrico , Ratones , Animales , Donantes de Óxido Nítrico/farmacología , Óxido Nítrico , Fluorescencia , Proliferación Celular
18.
Arch Microbiol ; 206(7): 289, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38847838

RESUMEN

Staphylococcus epidermidis is an opportunistic pathogen commonly implicated in medical device-related infections. Its propensity to form biofilms not only leads to chronic infections but also exacerbates the issue of antibiotic resistance, necessitating high-dose antimicrobial treatments. In this study, we explored the use of diclofenac sodium, a non-steroidal anti-inflammatory drug, as an anti-biofilm agent against S. epidermidis. In this study, crystal violet staining and confocal laser scanning microscope analysis showed that diclofenac sodium, at subinhibitory concentration (0.4 mM), significantly inhibited biofilm formation in both methicillin-susceptible and methicillin-resistant S. epidermidis isolates. MTT assays demonstrated that 0.4 mM diclofenac sodium reduced the metabolic activity of biofilms by 25.21-49.01% compared to untreated controls. Additionally, the treatment of diclofenac sodium resulted in a significant decrease (56.01-65.67%) in initial bacterial adhesion, a crucial early phase of biofilm development. Notably, diclofenac sodium decreased the production of polysaccharide intercellular adhesin (PIA), a key component of the S. epidermidis biofilm matrix, in a dose-dependent manner. Real-time quantitative PCR analysis revealed that diclofenac sodium treatment downregulated biofilm-associated genes icaA, fnbA, and sigB and upregulated negative regulatory genes icaR and luxS, providing potential mechanistic insights. These findings indicate that diclofenac sodium inhibits S. epidermidis biofilm formation by affecting initial bacterial adhesion and the PIA synthesis. This underscores the potential of diclofenac sodium as a supplementary antimicrobial agent in combating staphylococcal biofilm-associated infections.


Asunto(s)
Antibacterianos , Biopelículas , Diclofenaco , Staphylococcus epidermidis , Biopelículas/efectos de los fármacos , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/fisiología , Diclofenaco/farmacología , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Antiinflamatorios no Esteroideos/farmacología , Adhesión Bacteriana/efectos de los fármacos , Humanos , Polisacáridos Bacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/tratamiento farmacológico , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos
19.
Lupus ; 33(4): 365-374, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38320572

RESUMEN

BACKGROUND: Systemic lupus erythematosus is an immunologically dysregulated disease characterized by the presence of multiple autoantibodies. In SLE, B lymphocytes contribute to the dysregulated production of autoantibodies and cytokines. Recently, we discovered that miR-99a-3p binds to both EIF4EBP1 and NCAPG mRNA and that lowering miR-99a-3p can promote B cell autophagy in SLE by increasing EIF4EBP1 expression. However, the functions of miR-99a-3p and NCAPG in SLE have not been extensively investigated. OBJECTIVE: This work aims to evaluate the levels of miR-99a-3p and NCAPG expression in SLE B cells and to determine whether the aberrant expression of miR-99a-3p and NCAPG contributes to the pathological mechanisms in SLE. METHODS: B lymphocytes were obtained through immunomagnetic negative selection. Using RT-qPCR, miR-99a-3p and NCAPG mRNA expressions in B lymphocytes and in the BALL-1 cell line were measured. To determine the relative abundance of NCAPG, PI3K, p-PI3K, AKT, and p-AKT, we normalize them to the level of ß-actin using Western blotting. Evaluation of miR-99a-3p and NCAPG's impact on cell proliferation was done utilizing CCK-8 assay. Using flow cytometry, the cell cycle and apoptosis were both measured. RESULTS: Comparing SLE B cells to healthy controls, miR-99a-3p expression was significantly downregulated. Additionally, it was observed that SLE B cells had significantly higher NCAPG mRNA expression. Blocking miR-99a-3p expression in BALL-1 cells with an antagomir elevated NCAPG expression, facilitated PI3K/AKT pathway activation, improved cell proliferation, raised the fraction of S-phase cells, and prevented cell apoptosis. The opposite effects of upregulated miR-99a-3p levels on BALL-1 cells were observed by using an agomir. Furthermore, the effect of decreased miR-99a-3p expression on cell proliferation was partially mediated by elevating NCAPG levels and activating the PI3K/AKT pathway. CONCLUSION: Our research indicates that lower miR-99a-3p expression in SLE B cells appears to boost B cell number via the NCAPG and PI3K/AKT pathways.


Asunto(s)
Lupus Eritematoso Sistémico , MicroARNs , Humanos , Autoanticuerpos/farmacología , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/farmacología , Proliferación Celular/genética , MicroARNs/genética , MicroARNs/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , ARN Mensajero , Transducción de Señal
20.
Ecol Appl ; 34(3): e2967, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38469663

RESUMEN

The future ecosystem carbon cycle has important implications for biosphere-climate feedback. The magnitude of future plant growth and carbon accumulation depends on plant strategies for nutrient uptake under the stresses of nitrogen (N) versus phosphorus (P) limitations. Two archetypal theories have been widely acknowledged in the literature to represent N and P limitations on ecosystem processes: Liebig's Law of the Minimum (LLM) and the Multiple Element Limitation (MEL) approach. LLM states that the more limiting nutrient controls plant growth, and commonly leads to predictions of dramatically dampened ecosystem carbon accumulation over the 21st century. Conversely, the MEL approach recognizes that plants possess multiple pathways to coordinate N and P availability and invest resources to alleviate N or P limitation. We implemented these two contrasting approaches in the E3SM model, and compiled 98 in situ forest N or P fertilization experiments to evaluate how terrestrial ecosystems will respond to N and P limitations. We find that MEL better captured the observed plant responses to nutrient perturbations globally, compared with LLM. Furthermore, LLM and MEL diverged dramatically in responses to elevated CO2 concentrations, leading to a two-fold difference in CO2 fertilization effects on Net Primary Productivity by the end of the 21st century. The larger CO2 fertilization effects indicated by MEL mainly resulted from plant mediation on N and P resource supplies through N2 fixation and phosphatase activities. This analysis provides quantitative evidence of how different N and P limitation strategies can diversely affect future carbon and nutrient dynamics.


Asunto(s)
Dióxido de Carbono , Ecosistema , Dióxido de Carbono/metabolismo , Nitrógeno/metabolismo , Fósforo/análisis , Plantas , Carbono/metabolismo , Suelo
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