RESUMEN
The host always employs various ways to defend against viral infection and spread. However, viruses have evolved their own effective strategies, such as inhibition of RNA translation of the antiviral effectors, to destroy the host's defense barriers. Protein synthesis, commonly controlled by the α-subunit of eukaryotic translation initiation factor 2 (eIF2α), is a basic cellular biological process among all species. In response to viral infection, in addition to inducing the transcription of antiviral cytokines by innate immunity, infected cells also inhibit the RNA translation of antiviral factors by activating the protein kinase R (PKR)-eIF2α signaling pathway. Regulation of innate immunity has been well studied; however, regulation of the PKR-eIF2α signaling pathway remains unclear. In this study, we found that the E3 ligase TRIM21 negatively regulates the PKR-eIF2α signaling pathway. Mechanistically, TRIM21 interacts with the PKR phosphatase PP1α and promotes K6-linked polyubiquitination of PP1α. Ubiquitinated PP1α augments its interaction with PKR, causing PKR dephosphorylation and subsequent translational inhibition release. Furthermore, TRIM21 can constitutively restrict viral infection by reversing PKR-dependent translational inhibition of various previously known and unknown antiviral factors. Our study highlights a previously undiscovered role of TRIM21 in regulating translation, which will provide new insights into the host antiviral response and novel targets for the treatment of translation-associated diseases in the clinic.
Asunto(s)
ARN , Virosis , Humanos , ARN/metabolismo , eIF-2 Quinasa/metabolismo , Procesamiento Proteico-Postraduccional , Fosforilación , Antivirales , Factor 2 Eucariótico de Iniciación/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Replicación ViralRESUMEN
UPF1 is an RNA helicase that orchestrates nonsense-mediated decay and other RNA surveillance pathways. While UPF1 is best known for its basal cytoprotective role in degrading aberrant RNAs, UPF1 also degrades specific, normally occurring mRNAs to regulate diverse cellular processes. Here we describe a role for UPF1 in regulated protein decay, wherein UPF1 acts as an E3 ubiquitin ligase to repress human skeletal muscle differentiation. Suppressing UPF1 accelerates myogenesis, while ectopically increasing UPF1 levels slows myogenesis. UPF1 promotes the decay of MYOD protein, a transcription factor that is a master regulator of myogenesis, while leaving MYOD mRNA stability unaffected. UPF1 acts as an E3 ligase via its RING domain to promote MYOD protein ubiquitination and degradation. Our data characterize a regulatory role for UPF1 in myogenesis, and they demonstrate that UPF1 provides a mechanistic link between the RNA and protein decay machineries in human cells.
Asunto(s)
Diferenciación Celular , Desarrollo de Músculos , Músculo Esquelético/enzimología , Mioblastos Esqueléticos/enzimología , Transactivadores/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Regulación hacia Abajo , Femenino , Células HEK293 , Humanos , Masculino , Músculo Esquelético/citología , Proteína MioD/genética , Proteína MioD/metabolismo , Dominios Proteicos , Proteolisis , ARN Helicasas , Interferencia de ARN , Estabilidad del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de Señal , Factores de Tiempo , Transactivadores/química , Transactivadores/genética , Transcripción Genética , Transfección , UbiquitinaciónRESUMEN
Heme has attracted considerable attention due to its indispensable biological roles and applications in healthcare and artificial foods. The development and utilization of edible microorganisms instead of animals to produce heme is the most promising method to promote the large-scale industrial production and safe application of heme. However, the cytotoxicity of heme severely restricts its efficient synthesis by microorganisms, and the cytotoxic mechanism is not fully understood. In this study, the effect of heme toxicity on Saccharomyces cerevisiae was evaluated by enhancing its synthesis using metabolic engineering. The results showed that the accumulation of heme after the disruption of heme homeostasis caused serious impairments in cell growth and metabolism, as demonstrated by significantly poor growth, mitochondrial damage, cell deformations, and chapped cell surfaces, and these features which were further associated with substantially elevated reactive oxygen species (ROS) levels within the cell (mainly H2O2 and superoxide anion radicals). To improve cellular tolerance to heme, 5 rounds of laboratory evolution were performed, increasing heme production by 7.3-fold and 4.2-fold in terms of the titer (38.9 mg/L) and specific production capacity (1.4 mg/L/OD600), respectively. Based on comparative transcriptomic analyses, 32 genes were identified as candidates that can be modified to enhance heme production by more than 20% in S. cerevisiae. The combined overexpression of 5 genes (SPS22, REE1, PHO84, HEM4 and CLB2) was shown to be an optimal method to enhance heme production. Therefore, a strain with enhanced heme tolerance and ROS quenching ability (R5-M) was developed that could generate 380.5 mg/L heme with a productivity of 4.2 mg/L/h in fed-batch fermentation, with S. cerevisiae strains being the highest producers reported to date. These findings highlight the importance of improving heme tolerance for the microbial production of heme and provide a solution for efficient heme production by engineered yeasts.
RESUMEN
In immunology, cross-reaction between antigens and antibodies are commonly observed. Prior research has shown that various monoclonal antibodies (mAbs) can recognize a broad spectrum of epitopes related to influenza viruses. However, existing theories on cross-reactions fall short in explaining the phenomena observed. This study explored the interaction characteristics of H1-74 mAb with three peptides: two natural peptides, LVLWGIHHP and LPFQNI, derived from the hemagglutinin (HA) antigen of the H1N1 influenza virus, and one synthetic peptide, WPFQNY. Our findings indicate that the complementarity-determining region (CDR) of H1-74 mAb comprised five antigen-binding sites, containing eight key amino acid residues from the light chain variable region and 16 from the heavy chain variable region. These critical residues formed distinct hydrophobic or hydrophilic clusters and functional groups within the binding sites, facilitating interaction with antigen epitopes through hydrogen bonding, salt bridge formation, and π-π stacking. The study revealed that the formation of the antibody molecule led to the creation of binding groups and small units in the CDR, allowing the antibody to attach to a variety of antigen epitopes through diverse combinations of these small units and functional groups. This unique ability of the antibody to bind with antigen epitopes provides a new molecular basis for explaining the phenomenon of antibody cross-reaction.
Asunto(s)
Anticuerpos Monoclonales , Subtipo H1N1 del Virus de la Influenza A , Humanos , Secuencia de Aminoácidos , Aminoácidos , Epítopos , PéptidosRESUMEN
BACKGROUND: This study aimed to compare the efficacy of focused ultrasound (FUS) and the loop electrosurgical excision procedure (LEEP) for the treatment of cervical high-grade squamous intraepithelial lesions (HSILs) among women of reproductive age. METHODS: Case records of patients aged < 40 years who were treated for cervical HSILs using either FUS or LEEP from September 1, 2020 to May 31, 2022 were retrospectively reviewed. Patients were followed up for cure, recurrence, human papillomavirus (HPV) clearance, and complications within 1 year of treatment. Odds ratios and 95% confidence intervals were determined using univariate and multivariate logistic regression models to analyze the association between disease evidence or HPV clearance and treatment modalities or other covariates. RESULTS: Of the 1,054 women who underwent FUS or LEEP, 225 met our selection criteria. Among the selected women, 101 and 124 received FUS and LEEP, respectively. There was no significant difference between the FUS and LEEP groups in the cure rate during the 3-6 months of follow-up (89.11% vs. 94.35%, P = 0.085) and recurrence rate during the 6-12 months follow-up (2.22% vs. 1.71%, P = 0.790). Both groups exhibited enhanced cumulative HPV clearance rates; however, the rates were not significantly different between the FUS and LEEP groups (74.23% vs. 82.79%, P = 0.122 during the 3-6 months follow-up; 84.95% vs. 89.17%, P = 0.359 during the 6-12 months follow-up). Furthermore, the incidence of complications caused by the FUS and LEEP techniques was comparable (5.0% vs. 5.6%, P = 0.818). CONCLUSIONS: We found that FUS and LEEP have similar efficacy, safety, and reliability in treating women (aged < 40 years) with HSILs.
Asunto(s)
Infecciones por Papillomavirus , Lesiones Intraepiteliales Escamosas , Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Humanos , Femenino , Neoplasias del Cuello Uterino/patología , Estudios Retrospectivos , Electrocirugia/efectos adversos , Electrocirugia/métodos , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/cirugía , Reproducibilidad de los Resultados , Recurrencia Local de Neoplasia/epidemiologíaRESUMEN
Betulinic acid (BA) is a lupinane-type pentacyclic triterpenoid natural product derived from lupeol that has favorable anti-inflammatory and anti-tumor activities. Currently, BA is mainly produced via botanical extraction, which significantly limits its widespread use. In this study, we investigated the de novo synthesis of BA in Saccharomyces cerevisiae, and to facilitate the synthesis and storage of hydrophobic BA, we adopted a dual-engineering strategy involving peroxisomes and lipid droplets to construct the BA biosynthetic pathway. By expressing Betula platyphylla-derived lupeol C-28 oxidase (BPLO) and Arabidopsis-derived ATR1, we succeeded in developing a BA-producing strain and following multiple expression optimizations of the linker between BPLO and ATR1, the BA titer reached 77.53 mg/L in shake flasks and subsequently reached 205.74 mg/L via fed-batch fermentation in a 5-L bioreactor. In this study, we developed a feasible approach for the de novo synthesis of BA and its direct precursor lupeol in engineered S. cerevisiae.
RESUMEN
Sepsis, a life-threatening health issue, lacks effective medicine targeting the septic response. In China, treatment combining the intravenous herbal medicine XueBiJing with conventional procedures reduces the 28-day mortality of critically ill patients by modulating septic response. In this study, we identified the combined active constituents that are responsible for the XueBiJing's anti-sepsis action. Sepsis was induced in rats by cecal ligation and puncture (CLP). The compounds were identified based on their systemic exposure levels and anti-sepsis activities in CLP rats that were given an intravenous bolus dose of XueBiJing. Furthermore, the identified compounds in combination were assessed, by comparing with XueBiJing, for levels of primary therapeutic outcome, pharmacokinetic equivalence, and pharmacokinetic compatibility. We showed that a total of 12 XueBiJing compounds, unchanged or metabolized, circulated with significant systemic exposure in CLP rats that received XueBiJing. Among these compounds, hydroxysafflor yellow A, paeoniflorin, oxypaeoniflorin, albiflorin, senkyunolide I, and tanshinol displayed significant anti-sepsis activities, which involved regulating immune responses, inhibiting excessive inflammation, modulating hemostasis, and improving organ function. A combination of the six compounds, with the same respective doses as in XueBiJing, displayed percentage survival and systemic exposure in CLP rats similar to those by XueBiJing. Both the combination and XueBiJing showed high degrees of pharmacokinetic compatibility regarding interactions among the six active compounds and influences of other circulating XueBiJing compounds. The identification of XueBiJing's pharmacologically significant constituents supports the medicine's anti-sepsis use and provides insights into a polypharmacology-based approach to develop medicines for effective sepsis management.
Asunto(s)
Medicamentos Herbarios Chinos , Ratas Sprague-Dawley , Sepsis , Animales , Sepsis/tratamiento farmacológico , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/uso terapéutico , Medicamentos Herbarios Chinos/farmacocinética , Masculino , Ratas , Administración IntravenosaRESUMEN
BACKGROUND: Non-suicidal self-injury (NSSI) has exhibited an increasing trend in recent years and is now globally recognized as a major public health problem among adolescents and young adults. Negative life events (NLEs) are positively associated with NSSI. We sought to explore (1) whether sex plays a role in the risk of NLEs leading to NSSI and (2) the role played by mental health (MH). METHODS: We adopted a multi-stage cluster sampling method to select college students across four grades from May to June 2022. Generalized linear models were used to evaluate the relationships between NLEs, sex, MH and NSSI, presented as incidence-rate ratios (RRs) with 95% confidence intervals (CIs). We examined the complex relationship between these variables using the PROCESS method for moderation analysis. RESULTS: Following the exclusion of data that did not meet the study requirements, data from 3,578 students (mean age: 20.53 [± 1.65] years) were included. Poisson regression results indicate that high-level NLEs (RR = 0.110, 95%CI: 0.047-0.173) are associated with increased NSSI. Furthermore, interaction effects were observed among sex, NLEs and NSSI. MH and sex moderated the relationship between NLEs and NSSI. CONCLUSION: Identifying risk factors for NSSI is also important when exploring the interaction between NLEs and MH given the potential for NSSI to significantly increase the risk of later psychopathological symptoms and substance abuse problems. In addition, the significance of sex differences in risk factors for NSSI should be determined. This study evaluated how the impact of NLEs on NSSI can be reduced among adolescents from multiple perspectives.
Asunto(s)
Conducta Autodestructiva , Humanos , Conducta Autodestructiva/psicología , Conducta Autodestructiva/epidemiología , Masculino , Femenino , Adulto Joven , Adolescente , Factores Sexuales , Estudiantes/psicología , Adulto , Acontecimientos que Cambian la Vida , Factores de Riesgo , Salud MentalRESUMEN
Sample preparation, including extraction, separation, and purification, is a vital process for natural product analysis. As an attractive sample pretreatment method, magnetic solid-phase extraction (MSPE) has gained plenty of attention, mainly due to its simpler operation, less consumption of organic solvents, and shorter processing time than traditional SPE. This updated review is devoted to summarizing the applications of MSPE based on different magnetic nanomaterials in the analysis of various natural products in complex matrixes, such as biological samples, plants, and Chinese herbal preparations in the past four years (2020-2023). The preparation and fabrication of different materials are briefly introduced. Furthermore, the extraction mechanism and interaction forces between adsorbent and analytes are elaborated, and the advantages and disadvantages of different adsorbents coupled with various analytical methods for MSPE of different natural products are summarized. Moreover, the future trends and opportunities for MSPE in the natural product analysis are discussed. It is expected that this work can provide updated information for future research on the applications of MSPE in such fields.
RESUMEN
BACKGROUND: Social needs inhibit receipt of timely medical care. Social needs screening is a vital part of comprehensive cancer care, and patient navigators are well-positioned to screen for and address social needs. This mixed methods project describes social needs screening implementation in a prospective pragmatic patient navigation intervention trial for minoritized women newly diagnosed with breast cancer. METHODS: Translating Research Into Practice (TRIP) was conducted at five cancer care sites in Boston, MA from 2018 to 2022. The patient navigation intervention protocol included completion of a social needs screening survey covering 9 domains (e.g., food, transportation) within 90 days of intake. We estimated the proportion of patients who received a social needs screening within 90 days of navigation intake. A multivariable log binomial regression model estimated the adjusted rate ratios (aRR) and 95% confidence intervals (CI) of patient socio-demographic characteristics and screening delivery. Key informant interviews with navigators (n = 8) and patients (n = 21) assessed screening acceptability and factors that facilitate and impede implementation. Using a convergent, parallel mixed methods approach, findings from each data source were integrated to interpret study results. RESULTS: Patients' (n = 588) mean age was 59 (SD = 13); 45% were non-Hispanic Black and 27% were Hispanic. Sixty-nine percent of patients in the navigators' caseloads received social needs screening. Patients of non-Hispanic Black race/ethnicity (aRR = 1.25; 95% CI = 1.06-1.48) and those with Medicare insurance (aRR = 1.13; 95% CI = 1.04-1.23) were more likely to be screened. Screening was universally acceptable to navigators and generally acceptable to patients. Systems-based supports for improving implementation were identified. CONCLUSIONS: Social needs screening was acceptable, yet with modest implementation. Continued systems-based efforts to integrate social needs screening in medical care are needed.
Asunto(s)
Neoplasias de la Mama , Navegación de Pacientes , Humanos , Femenino , Neoplasias de la Mama/diagnóstico , Persona de Mediana Edad , Estudios Prospectivos , Anciano , Evaluación de Necesidades , Boston , AdultoRESUMEN
Ergothioneine (EGT) is a rare thiohistidine derivative with exceptional antioxidant properties. The blood level of EGT is considered highly reliable predictors for cardiovascular diseases and mortality, yet animals lack the ability to synthesize this compound. Free plasmids have been previously used to overexpress genes involved in the EGT biosynthetic pathway of Mycolicibacterium neoaurum. Here, we tentatively introduced a putative transporter gene mfsT1 into high-copy plasmids and sharply increased the ratio of extracellular EGT concentration from 18.7% to 44.9%. Subsequently, an additional copy of egtABCDE, hisG, and mfsT1 was inserted into the genome with a site-specific genomic integration tool of M. neoaurum, leading a 2.7 times increase in EGT production. Co-enhancing the S-adenosyl-L-methionine regeneration pathway, or alternatively, the integration of three copies of egtABCDE, hisG and mfsT1 into the genome further increased the total EGT yield by 16.1% (64.6 mg/L) and 21.7% (67.7 mg/L), respectively. After 168-h cultivation, the highest titer reached 85.9 mg/L in the latter strain with three inserted copies. This study provided a solid foundation for genome engineering to increase the production of EGT in M. neoaurum.
Asunto(s)
Ergotioneína , Mycobacteriaceae , Animales , Ergotioneína/genética , Ergotioneína/metabolismo , Antioxidantes/metabolismoRESUMEN
Two new rare trachylobane euphoratones A-B (1-2), together with five known diterpenoids (compounds 3-7), were isolated from the aerial parts of Euphorbia atoto. Their structures were unambiguously elucidated through HRESIMS, 1D and 2D NMR spectral analysis. Compounds 1, 3, 4 and 7 showed weak anti-inflammatory activities (IC50 77.49 ± 6.34, 41.61 ± 14.49, 16.00 ± 1.71 and 33.41 ± 4.52 µM, respectively), compared to the positive control quercetin (IC50 15.23 ± 0.65 µM).
Asunto(s)
Diterpenos , Euphorbia , Estructura Molecular , Euphorbia/química , Espectroscopía de Resonancia Magnética , Diterpenos/farmacología , Diterpenos/química , Antiinflamatorios/farmacología , Antiinflamatorios/químicaRESUMEN
Chiral molecules have similar physicochemical properties, which are different in terms of physiological activities and toxicities, rendering their differentiation and recognition highly significant. Nanozymes, which are nanomaterials with inherent enzyme-like activities, have garnered significant interest owing to their high cost-effectiveness, enhanced stability, and straightforward synthesis. However, constructing nanozymes with high activity and enantioselectivity remains a significant challenge. This review briefly introduces the synthesis methods of chiral nanozymes and systematically summarizes the latest research progress in enantioselective recognition of chiral molecules based on electrochemical methods and ultraviolet-visible absorption spectroscopy. Moreover, the challenges and development trends in developing enantioselective nanozymes are discussed. It is expected that this review will provide new ideas for the design of multifunctional chiral nanozymes and broaden the application field of nanozymes.
Asunto(s)
Técnicas Electroquímicas , Nanoestructuras , Espectrofotometría Ultravioleta , Estereoisomerismo , Nanoestructuras/químicaRESUMEN
The high toxicity of arsenic (As) can cause irreversible harm to the environment and human health. In this study, the chlorin e6 (Ce6), which emits fluorescence in the infrared region, was introduced as the luminescence center, and the addition of copper ion (Cu2+) and As(V) provoked a regular change in fluorescence at 652 nm, whereas that of As(III) was 665 nm, which was used to optionally detect Cu2+, arsenic (As(III), and As(V)). The limit of detection (LOD) values were 0.212 µM, 0.089 ppm, and 1.375 ppb for Cu2+, As(III), and As(V), respectively. The developed method can be used to determine Cu2+ and arsenic in water and soil with good sensitivity and selectivity. The 1:1 stoichiometry of Ce6 with Cu2+ was obtained from the Job plot that was developed from UV-visible spectra. The binding constants for Cu2+ and As(V) were established to be 1.248 × 105 M-1 and 2.35 × 1012 M-2, respectively, using B-H (Benesi-Hildebrand) plots. Fluorescence lifetimes, B-H plots, FT-IR, and 1H-NMR were used to postulate the mechanism of Cu2+ fluorescence quenching and As(V) fluorescence restoration and the interactions of the two ions with the Ce6 molecule.
Asunto(s)
Arsénico , Clorofilidas , Porfirinas , Humanos , Cobre/química , Espectroscopía Infrarroja por Transformada de Fourier , Iones , Espectrometría de Fluorescencia , Colorantes Fluorescentes/químicaRESUMEN
Rehmannia glutinosa is one of the commonly used Chinese herbal medicines, which has activities of heat-clearing,blood-cooling, Yin-nourishing, and body fluid-promoting. Iridoid glycosides are the main bioactive in R. glutinosa. Iridoid oxidase is a key rate-limiting enzyme in the biosynthetic pathway of iridoid glycosides. In this study, an iridoid oxidase gene Rg IO was screened based on the transcriptome data, followed by bioinformatics analysis, expression characteristic detection, and subcellular localization analysis. The results show that the coding region of Rg IO is 1 536 bp, with 511 amino acids encoded, and the molecular weight is about 58 258. 01. The protein sequence of Rg IO contains the conserved domains and motifs of cytochrome P450 oxidases. Rg IO has the highest sequence identities with its ortholog proteins in Striga asiatica, Striga hermonthica, and Centranthera grandiflora and has good sequence identities(77. 28%) with Catharanthus roseus Cr IO. Rg IO shows specific expression in the leaf of R. glutinosa. In response to MeJA induction, the expression of MeJA in leaves and roots after treatment increases by 3. 15 and 1. 3 times at 3 h and 6 h,respectively. The result of subcellular localization shows that Rg IO is distributed in the endoplasmic reticulum. Agrobacterium-mediated transient expression of Rg IO gene in leaves of R. glutinosa makes the content of catalpol increase by 0. 82 times compared with the transient expression of the empty vector. This study provides a key target gene for the molecular regulation and biosynthesis of catalpol in R. glutinosa and lays a foundation for revealing the complete biosynthetic pathway of catalpol.
Asunto(s)
Clonación Molecular , Proteínas de Plantas , Rehmannia , Rehmannia/genética , Rehmannia/enzimología , Rehmannia/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química , Regulación de la Expresión Génica de las Plantas , Filogenia , Secuencia de AminoácidosRESUMEN
Lonicera macranthoides (LM) and L. japonica (LJ) are medicinal plants widely used in treating viral diseases, such as COVID-19. Although the two species are morphologically similar, their secondary metabolite profiles are significantly different. Here, metabolomics analysis showed that LM contained ~86.01 mg/g hederagenin-based saponins, 2000-fold higher than LJ. To gain molecular insights into its secondary metabolite production, a chromosome-level genome of LM was constructed, comprising 9 pseudo-chromosomes with 40 097 protein-encoding genes. Genome evolution analysis showed that LM and LJ were diverged 1.30-2.27 million years ago (MYA). The two plant species experienced a common whole-genome duplication event that occurred â¼53.9-55.2 MYA before speciation. Genes involved in hederagenin-based saponin biosynthesis were arranged in clusters on the chromosomes of LM and they were more highly expressed in LM than in LJ. Among them, oleanolic acid synthase (OAS) and UDP-glycosyltransferase 73 (UGT73) families were much more highly expressed in LM than in LJ. Specifically, LmOAS1 was identified to effectively catalyse the C-28 oxidation of ß-Amyrin to form oleanolic acid, the precursor of hederagenin-based saponin. LmUGT73P1 was identified to catalyse cauloside A to produce α-hederin. We further identified the key amino acid residues of LmOAS1 and LmUGT73P1 for their enzymatic activities. Additionally, comparing with collinear genes in LJ, LmOAS1 and LmUGT73P1 had an interesting phenomenon of 'neighbourhood replication' in LM genome. Collectively, the genomic resource and candidate genes reported here set the foundation to fully reveal the genome evolution of the Lonicera genus and hederagenin-based saponin biosynthetic pathway.
Asunto(s)
COVID-19 , Lonicera , Ácido Oleanólico , Plantas Medicinales , Saponinas , Humanos , Ácido Oleanólico/química , Ácido Oleanólico/metabolismo , Lonicera/genética , Lonicera/metabolismo , Plantas Medicinales/genética , Plantas Medicinales/metabolismo , Saponinas/genética , Saponinas/química , Genómica , Evolución MolecularRESUMEN
In drug discovery, one of the most important tasks is to find novel and biologically active molecules. Given that only a tip of iceberg of drugs was founded in nearly one-century's experimental exploration, it shows great significance to use in silico methods to expand chemical database and profile drug-target linkages. In this study, a web server named ChemGenerator was proposed to generate novel activates for specific targets based on users' input. The ChemGenerator relies on an autoencoder-based algorithm of Recurrent Neural Networks with Long Short-Term Memory by training of 7 million of molecular Simplified Molecular-Input Line-Entry System as the basic model, and further develops target guided generation by transfer learning. As results, ChemGenerator gains lower loss (<0.01) than existing reference model (0.2~0.4) and shows good performance in the case of Epidermal Growth Factor Receptor. Meanwhile, ChemGenerator is now freely accessible to the public by http://smiles.tcmobile.org. In proportion to endless molecular enumeration and time-consuming expensive experiments, this work demonstrates an efficient alternative way for the first virtual screening in drug discovery.
Asunto(s)
Bases de Datos de Compuestos Químicos , Descubrimiento de Drogas , Internet , Redes Neurales de la Computación , Programas Informáticos , LigandosRESUMEN
Influenza virus infection can cause kidney damage. However, the link between influenza infection and disease is still unclear. The purpose of this study was to analyze the relationship between heterophilic epitopes on H5N1 hemagglutinin (HA) and disease. The monoclonal antibody (mAb) against H5N1 was prepared, mAbs binding to human kidney tissue were screened, and the reactivities of mAbs with five different subtypes of influenza virus were detected. Design and synthesize the peptides according to the common amino acid sequence of these antigens, and analyze the distribution of the epitope on the crystal structure of HA. Immunological methods were used to detect whether the heterophilic epitopes could induce the production of antibodies that cross-react with kidney tissue. The results showed that H5-30 mA b binding to human kidney tissue recognized the heterophilic epitope 191-LVLWGIHHP-199 on the head of HA. The key amino acid were V192, L193, W194 and I196, which were highly conserved in human and avian influenza virus HA. The heterophilic epitope could induce mice to produce different mAbs binding to kidney tissue. Such heterophilic antibodies were also detected in the serum of the patients. It can provide materials for the mechanism of renal diseases caused by influenza virus infection.
Asunto(s)
Subtipo H5N1 del Virus de la Influenza A , Virus de la Influenza A , Gripe Aviar , Gripe Humana , Humanos , Animales , Ratones , Epítopos , Hemaglutininas , Mapeo Epitopo/métodos , Glicoproteínas Hemaglutininas del Virus de la Influenza , Anticuerpos Antivirales , Anticuerpos Monoclonales , RiñónRESUMEN
As a valuable biomarker for various tumor, sensitive and reliable quantitative determination of microRNA (miRNA) is crucial for both disease diagnosis and cancer treatment. Herein, we depict a novel simple and sensitive miRNA detection approach by exploiting an elegantly designed target recognition initiated self-dissociation based DNA nanomachine. In this nanomachine, target recognition assists the formation of active DNAzyme secondary conformation, and the active DNAzyme generates a nicking site in H probe, initiating the self-assembly of H probe. With the reflexed sequences as primer, dual signal recycles are formed under the cooperation of DNA polymerase and Nb.BbvCI. Eventually, the method exhibits a high sensitivity with the limit of detection as low as 12 fM. In addition, the method is also demonstrated with a high selectivity that can distinguish one mismatched base pair. We believe the established approach can be a robust tool for the early-diagnosis of a variety of cancers and also in anticancer drug development.
Asunto(s)
Técnicas Biosensibles , ADN Catalítico , MicroARNs , MicroARNs/genética , Técnicas Biosensibles/métodos , ADN , Límite de Detección , Técnicas de Amplificación de Ácido Nucleico/métodosRESUMEN
Thermoelectric (TE) performance of the Janus ZrSSe monolayer under biaxial strain is systematically explored by the first-principles approach and Boltzmann transport theory. Our results show that the Janus ZrSSe monolayer has excellent chemical, dynamical, thermal, and mechanical stabilities, which provide a reliable platform for strain tuning. The electronic structure and TE transport parameters of the Janus ZrSSe monolayer can be obviously tuned by biaxial strain. Under 2% tensile strain, the optimal power factor PF of the n-type-doped Janus ZrSSe monolayer reaches 46.36 m W m-1 K-2 at 300 K. This value is higher than that of the most classical TE materials. Under 6% tensile strain, the maximum ZT values for the p-type- and n-type-doped Janus ZrSSe monolayers are 4.41 and 4.88, respectively, which are about 3.83 and 1.49 times the results of no strain, respectively. Such high TE performance can be attributed to high band degeneracy and short phonon relaxation time under strain, causing simultaneous increase of the Seebeck coefficient and suppression of the phonon thermal transport. Present work demonstrates that the Janus ZrSSe monolayer is a promising candidate as a strain-tunable TE material and stimulates further experimental synthesis.