Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 102
Filtrar
1.
Sci Total Environ ; : 161549, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36640892

RESUMO

Due to the rising usage of plastics, plastic debris are present throughout marine ecosystems and detrimentally affects marine biota. Additionally, plastics likely result in elusive toxicity effects due to addition of plasticizers. The aim of the present study was to reveal the potential effects and mechanism of microplastics (MPs), di-(2-ethylhexyl) phthalate (DEHP) and copollution of MPs and DEHP (MPs-DEHP) on Peneaus vannamei (P. vannamei) juveniles regarding oxidative stress, transcriptomics and metabolomics. MPs, DEHP and MPs-DEHP significantly induced the activities of superoxide dismutase (SOD) and catalase (CAT); MPs and DEHP have an antagonistic effect for malondialdehyde (MDA); suggesting that disorders of the antioxidant defence systems. 13, 133 and 58 differentially expressed genes and 21, 82 and 39 differentially expressed metabolites were responsible for the distinction of MPs, DEHP and MPs-DEHP groups, respectively. The combination of transcriptomic and metabolomic analyses showed that MPs, DEHP and MPs-DEHP exposure disturbed amino acid and lipid metabolism, and further induced inflammatory responses and dysfunction of purine metabolism. Furthermore, the presence of MPs might alleviate the biotoxicity of DEHP in P. vannamei. These findings provide new insights into the single and combined toxicological effects of MPs and additives for marine biota.

2.
J Med Virol ; 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36594413

RESUMO

Zika virus (ZIKV) is a mosquito-borne RNA virus that belongs to the Flaviviridae family. While flavivirus replication is known to occur in the cytoplasm, a significant portion of the viral capsid protein localizes to the nucleus during infection. However, the role of nuclear capsid is less clear. Herein, we demonstrated SERTA domain containing 3 (SERTAD3) as an antiviral interferon stimulatory gene product had an antiviral ability to ZIKV but not JEV. Mechanistically, we found that SERTAD3 interacted with the capsid protein of ZIKV in the nucleolus and reduced capsid protein abundance through proteasomal degradation. Furthermore, an eight amino acid peptide of SERTAD3 was identified as the minimum motif that binds with ZIKV capsid protein. Remarkably, the 8 amino acid synthetic peptide from SERTAD3 significantly prevented ZIKV infection in culture and pregnant mouse models. Taken together, these findings not only reveal the function of SERTAD3 in promoting proteasomal degradation of a specific viral protein but also provide a promising host-targeted therapeutic strategy against ZIKV infection. This article is protected by copyright. All rights reserved.

3.
Microb Pathog ; : 105924, 2022 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-36473667

RESUMO

Piglet diarrhea caused by the porcine epidemic diarrhea virus (PEDV) is a common problem on pig farms in China associated with high morbidity and mortality rates. In this study, three PEDV isolates were successfully detected after the fourth blind passage in Vero cells. The samples were obtained from infected piglet farms in Jilin (Changchun), and Shandong (Qingdao) Provinces of China and were designated as CH/CC-1/2018, CH/CC-2/2018, and CH/QD/2018. According to the analysis of the complete S protein gene sequence, the CH/CC-1/2018 and CH/CC-2/2018 were allocated to the G2b branch, while CH/QD/2018 was located in the G1a interval and was closer to the vaccine strain CV777. Successful detection and identification of the isolated strains were carried out using electron microscopy and indirect immunofluorescence. Meanwhile, animal challenge experiments and viral RNA copies determination were used to compare the pathogenicity. The results showed that CH/CC-1/2018 in Changchun was more pathogenic than CH/QD/2018 in Qingdao. In conclusion, the discovery of these new strains is conducive to the development of vaccines to prevent the pandemic of PEDV, especially that the CH/CC-1/2018, and CH/CC-2/2018 were not related to the classical vaccine strain CV777.

4.
J Ethnopharmacol ; 303: 115944, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36410574

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Fuzheng Xiaoai Decoction 1 (FZXAD1) is a clinical experience prescription for the treatment of cancer patients at an advanced stage. FZXAD1 has been used for more than 10 years in the clinic and can effectively improve the deficiency syndrome of cancer patients. However, its mechanisms need further clarification. AIM OF THE STUDY: To check the effects of FZXAD1 in colon 26 (C26) cancer cachexia mice and try to clarify the mechanisms of FZXAD1 in ameliorating cancer cachexia symptoms. MATERIALS AND METHODS: An animal model of cancer cachexia was constructed with male BALB/c mice bearing C26 tumor cells. Food intake, body weight and tumor size were measured daily during the animal experiment. Tissue samples in different groups including tumor and gastrocnemius muscle, were dissected and weighed at the end of the assay. Serum biochemical indicators such as total protein (TP), glucose (GLU) and alkaline phosphatase (ALP) were also detected. Network pharmacology-based analysis predicted the possible targets and signaling pathways involved in the effects of FZXAD1 on cancer cachexia therapy. Western blotting assays of the gastrocnemius muscle tissues from C26 tumor-bearing mice were then used to confirm the predicted possible targets of FZXAD1. RESULTS: The results of animal experiments showed that FZXAD1 could ameliorate cancer cachexia by alleviating the muscle wasting as well as kidney atrophy and increasing the body weight of cancer cachexia mice. AKT1, MTOR, MAPK3, HIF1A and MAPK1 were predicted as the core targets of FZXAD1. Western blotting confirmed the prediction that FZXAD1 increased the expression levels of phosphorylated Akt and mTOR in the muscle tissues. In addition, FZXAD1 treatment obviously ameliorated the increased levels of HIF-1α and phosphorylated Erk1/2 in C26 tumor-bearing mice. CONCLUSION: FZXAD1 effectively ameliorated cancer cachexia in an animal model of mice, which is consistent with its efficacy in the treatment of cancer patients. The mechanisms of FZXAD1 might be mainly based on its alleviating effects on muscle atrophy by activating the Akt-mTOR pathway and thus helping to maintain body weight.

5.
Res Vet Sci ; 153: 115-126, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36351352

RESUMO

Avian influenza virus (AIV)is easy to cause diseases in birds and humans.It causes great economic losses to the poultry farms and leads to public health problems. Using vaccines is the main approach to control the prevalence of AIV. In our previously published article, a recombinant Lactobacillus plantarum (L. plantarum) expressing the NP-M2 peptide ofH9N2 AIV was generated, and its protective effect was evaluated in a chicken model. In this study, the protective effect was estimated in mice model. Humoral and cellular immune response parameters were measured using flow cytometry adding to body weight loss, survival rate, virus load, and histopathological changes in the lung. The obtained results elucidated that, the recombinant L. plantarum can promote the activation of dendritic cells (DC), proliferation of T and B cells adding to eliciting protective secretory IgA (sIgA) and humeral IgG level in mice model. Accordingly, it could be used as a patent vaccine to control the AIV infection.

6.
Sensors (Basel) ; 22(18)2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36146335

RESUMO

Absolute pose regression (APR) for camera localization is a single-shot approach that encodes the information of a 3D scene in an end-to-end neural network. The camera pose result of APR methods can be observed as the linear combination of the base poses. Previous APR methods' base poses are learned from training data. However, the training data can limit the performance of the methods, which cannot be generalized to cover the entire scene. To solve this issue, we use handcrafted base poses instead of learning-based base poses, which prevents overfitting the camera poses of the training data. Moreover, we use a dual-stream network architecture to process color and depth images separately to get more accurate localization. On the 7 Scenes dataset, the proposed method is among the best in median rotation error, and in median translation error, it outperforms previous APR methods. On a more difficult dataset-Oxford RobotCar dataset, the proposed method achieves notable improvements in median translation and rotation errors compared to the state-of-the-art APR methods.

7.
Emerg Microbes Infect ; 11(1): 2350-2358, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36069671

RESUMO

Zika virus (ZIKV) is primarily transmitted through mosquito bites and sexual contact, and vertical transmission of ZIKV has also been observed in humans. In addition, ZIKV infection via unknown transmission routes has been frequently reported in clinical settings. However, whether ZIKV can be transmitted via aerosol routes remains unknown. In this study, we demonstrated that aerosolized ZIKV is fully infectious in vitro and in vivo. Remarkably, intratracheal (i.t.) inoculation with aerosolized ZIKV led to rapid viremia and viral secretion in saliva, as well as robust humoral and innate immune responses in guinea pigs. Transcriptome analysis further revealed that the expression of genes related to viral processes, biological regulation and the immune response was significantly changed. Together, our results confirm that aerosolized ZIKV can result in systemic infection and induce both innate and adaptive immune responses in guinea pigs, highlighting the possibility of ZIKV transmission via aerosols.


Assuntos
Infecção por Zika virus , Zika virus , Animais , Cobaias , Humanos , Imunidade Humoral , Transmissão Vertical de Doenças Infecciosas , Viremia , Zika virus/fisiologia
8.
Mamm Genome ; 33(4): 642-653, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35994105

RESUMO

BACKGROUND: Sepsis-induced acute kidney injury (AKI) is a common in clinic. Circular RNAs (circRNAs) play significant roles in ameliorating AKI. The purpose of this study was aimed to identify the role of circ_0074371 and the potential action mechanism in sepsis-induced AKI. METHODS: AKI patients and healthy individual serum samples were collected and the relative expression of circ_0074371 was measured by real-time polymerase chain reaction (RT-PCR). HK2 cells were treated with different dose (0, 2.5, 5 and 10 µg/ml) lipopolysaccharide (LPS) to establish the AKI cell model. The cell viability and apoptosis of HK2 cells were detected using cell counting kit-8 (CCK-8) and flow cytometry, respectively. The contents of malondialdehyde (MDA), and superoxide dismutase (SOD) were evaluated using the relative commercial kits. The IL-1ß and TNF-α levels in cell culture supernatants were measured by ELISA. The interaction relationship between miR-330-5p and circ_0074371 or ELK1 was predicted by Targetscan database and further confirmed by the dual-luciferase reporter assay system. RESULTS: The circ_0074371 expression was up-regulated in sepsis patients and LPS-induced HK2 cells. Silencing circ_0074371 promoted HK2 cells viability and inhibited the HK2 cells apoptosis. miR-330-5p inhibitor weakened circ_0074371 inhibitor-induced cell viability, apoptosis and oxidative stress. Further mechanism analysis showed that circ_0074371 acted as a sponge for miR-330-5p to increase ELK1 expression level. Importantly, miR-330-5p downregulation or ELK1 upregulation reversed the action of circ_0074371 knockdown on LPS-induced HK2 cells. CONCLUSION: Knockdown of circ_0074371 ameliorated LPS-induced HK2 cells apoptosis, inflammation and oxidative stress via regulating miR-330-5p/ELK1, opening a new window into the pathogenesis AKI.


Assuntos
Injúria Renal Aguda , MicroRNAs , Sepse , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Proliferação de Células/fisiologia , Lipopolissacarídeos/toxicidade , Apoptose/genética , Injúria Renal Aguda/genética , Sepse/complicações , Sepse/genética , Proteínas Elk-1 do Domínio ets/genética
9.
Cell Biosci ; 12(1): 139, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36042495

RESUMO

BACKGROUND: Recognition of viral invasion by innate antiviral immune system triggers activation of the type I interferon (IFN-I) and proinflammatory signaling pathways. Subsequently, IFN-I induction regulates expression of a group of genes known as IFN-I-stimulated genes (ISGs) to block viral infection. The tripartite motif containing 22 (TRIM22) is an ISG with strong antiviral functions. RESULTS: Here we have shown that the TRIM22 has been strongly upregulated both transcriptionally and translationally upon Zika virus (ZIKV) infection. ZIKV infection is associated with a wide range of clinical manifestations in human from mild to severe symptoms including abnormal fetal brain development. We found that the antiviral function of TRIM22 plays a crucial role in counterattacking ZIKV infection. Overexpression of TRIM22 protein inhibited ZIKV growth whereas deletion of TRIM22 in host cells increased ZIKV infectivity. Mechanistically, TRIM22, as a functional E3 ubiquitin ligase, promoted the ubiquitination and degradation of ZIKV nonstructural protein 1 (NS1) and nonstructural protein 3 (NS3). Further studies showed that the SPRY domain and Ring domain of TRIM22 played important roles in protein interaction and degradation, respectively. In addition, we found that TRIM22 also inhibited other flaviviruses infection including dengue virus (DENV) and yellow fever virus (YFV). CONCLUSION: Thus, TRIM22 is an ISG with important role in host defense against flaviviruses through binding and degradation of the NS1 and NS3 proteins.

10.
Front Microbiol ; 13: 820484, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35847111

RESUMO

There are some limitations of traditional influenza vaccines concerning novel mutant strains. Therefore, it is particularly important to develop preventive means for antigen-unrelated types of influenza viruses. Recent studies have shown that probiotics can modulate the immune system and reduce the severity of viral infections. In this study, we investigated the potential of Lactiplantibacillus plantarum 0111 against influenza virus H9N2. Challenge experiments showed that L. plantarum 0111 pretreatments could effectively improve mice's survival rate and weight loss and reduce the inflammatory cytokines IL-6 and TNF-α in the lungs and bronchoalveolar lavage fluid (BALF) along with the degree of lung and intestinal injury. FMT experiment demonstrates that the protective effect produced by L. plantarum 0111 is associated with gut microorganisms. In addition, 16S high-throughput sequencing of the mouse intestinal microbiota showed that L. plantarum 0111 remodeled the intestinal microbiota after H9N2 infection and maintained the gut microbiota balance. In a mouse model, the oral administration of L. plantarum 0111 increased IFN-ß expression in the serum and BALF. At the same time, the transcript levels of IFN-ß and related ISGs in the intestine and lungs of mice were also increased. In addition, the activation and polarization of T cells in mesenteric lymph nodes (MLNs) and the spleen were detected by flow cytometry, and the results showed that L. plantarum 0111 modulated cytokines in T cells and increased IgA expression in B cells in the MLNs and spleen. Thus, L. plantarum 0111 may improve gut microbiota-mediated immune responses and thus, resist infection by the influenza virus, and it could be used as an effective preventive measure against the influenza virus.

11.
Sci Total Environ ; 848: 157675, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35907542

RESUMO

A tricolor ratiometric fluorescence sensor was fabricated by mixing blue- and red-emission molecularly imprinted quantum dots (MIP-QDs) with green-emission quantum dots at the optimal ratio. The MIP-QDs were synthesized by coating CdSe/ZnS QDs in polymer by inverse microemulsion method. Compared with single-emission or dual-emission sensors, the tricolor ratiometric fluorescence sensor provided a wider range of color variations for visual DBP detection. The ratio fluorescence value I530/(I450 + I630) of the tricolor ratiometric fluorescence sensor linearly changed within the concentration of 2.0-20.0 × 103 µg/L DBP. The correlation coefficient was 0.9910, and the limits of detection were 1.0 µg/kg and 0.65 µg/L in fish and seawater, respectively. Meanwhile, the fluorescence color gradually changed from purple to plum to pink to salmon to yellowish green and finally to green. The recoveries of DBP in fish and seawater were 84.3 %-91.4 % and 88.3 %-110.3 %, respectively. Moreover, no obvious differences were observed between the detection results of the tricolor ratiometric fluorescence sensor and gas chromatography-tandem mass spectrometry. The tricolor ratiometric fluorescence sensor constructed herein provides an ideal choice for rapid and intuitive DBP detection in environmental and aquatic products.


Assuntos
Impressão Molecular , Nanopartículas , Animais , Dibutilftalato , Corantes Fluorescentes , Cromatografia Gasosa-Espectrometria de Massas , Impressão Molecular/métodos , Polímeros/química , Água do Mar
13.
Plant Sci ; 322: 111367, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35788027

RESUMO

The phytochrome-interacting factor (PIF) subfamily of basic helix-loop-helix (bHLH) transcription factors plays a critical role in plant growth and development. However, there has been no detailed report on the PIFs in carrot. In this study, we present the identification and characterization of DcPIF gene family in carrot (Daucus carota L.). Phylogenetic analysis indicated that PIFs from carrot and other five plant species could be divided into four groups supported by similar gene structure and motif analysis. Expression profiles showed that all DcPIF genes were tissue-specific and could be induced by drought or abscisic acid (ABA) treatment except DcPIF7.1, among which DcPIF3 was the most responsive. The DcPIF3-overexpressed Arabidopsis plants exhibited more tolerance to drought stress, with higher antioxidant capacity and lower malondialdehyde content after drought treatment than wild type plants. Further stress tolerance assays revealed that DcPIF3 plays a positive role in drought stress by increasing endogenous ABA level and promoting the expression of ABA-related genes. Our results can enrich the understanding of DcPIF family genes and lay a foundation for further investigation of DcPIF3 function to defend against drought stress in carrot.


Assuntos
Arabidopsis , Daucus carota , Fitocromo , Ácido Abscísico/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Daucus carota/genética , Daucus carota/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Filogenia , Fitocromo/genética , Fitocromo/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Estresse Fisiológico/genética
14.
NPJ Vaccines ; 7(1): 84, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35882870

RESUMO

As the world continues to experience the COVID-19 pandemic, seasonal influenza remain a cause of severe morbidity and mortality globally. Worse yet, coinfection with SARS-CoV-2 and influenza A virus (IAV) leads to more severe clinical outcomes. The development of a combined vaccine against both COVID-19 and influenza is thus of high priority. Based on our established lipid nanoparticle (LNP)-encapsulated mRNA vaccine platform, we developed and characterized a novel mRNA vaccine encoding the HA antigen of influenza A (H1N1) virus, termed ARIAV. Then, ARIAV was combined with our COVID-19 mRNA vaccine ARCoV, which encodes the receptor-binding domain (RBD) of the SARS-CoV-2 S protein, to formulate the final combined vaccine, AR-CoV/IAV. Further characterization demonstrated that immunization with two doses of AR-CoV/IAV elicited robust protective antibodies as well as antigen-specific cellular immune responses against SARS-CoV-2 and IAV. More importantly, AR-CoV/IAV immunization protected mice from coinfection with IAV and the SARS-CoV-2 Alpha and Delta variants. Our results highlight the potential of the LNP-mRNA vaccine platform in preventing COVID-19 and influenza, as well as other respiratory diseases.

15.
J Adv Res ; 2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35753652

RESUMO

BACKGROUND: Lycopene is a natural red compound with potent antioxidant activity that can be utilized both as pigment and as a raw material in functional food, and so possesses good commercial prospects. The biosynthetic pathway has already been documented, which provides the foundation for lycopene production using biotechnology. AIM OF REVIEW: Although lycopene production has begun to take shape, there is still an urgent need to alleviate the yield of lycopene. Progress in this area can provide useful reference for metabolic engineering of lycopene production utilizing multiple approaches. Key scientific concepts of review. Using conventional microbial fermentation approaches, biotechnologists have enhanced the yield of lycopene by selecting suitable host strains, utilizing various additives, and optimizing culture conditions. With the development of modern biotechnology, genetic engineering, protein engineering, and metabolic engineering have been applied for lycopene production. Extraction from natural plants is the main way for lycopene production at present. Based on the molecular mechanism of lycopene accumulation, the production of lycopene by plant bioreactor through genetic engineering has a good prospect. Here we summarized common strategies for optimizing lycopene production engineering from a biotechnology perspective, which are mainly carried out by microbial cultivation. We reviewed the challenges and limitations of this approach, summarized the critical aspects, and provided suggestions with the aim of potential future breakthroughs for lycopene production in plants.

16.
Chin J Nat Med ; 20(3): 202-209, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35369964

RESUMO

Two cardenolide glycosides, corotoxigenin 3-O-[ß-D-glucopyranosyl-(1→4)-6-deoxy-ß-D-glucopyranoside] (1) and coroglaucigenin 3-O-[ß-D-glucopyranosyl-(1→4)-6-deoxy-ß-D-glucopyranoside] (2), were isolated from the seed fairs of Asclepias curassavica. The structures of 1-2 were determined based on the combination of the analysis of their MS, NMR spectroscopic data and acid hydrolysis. The inhibitory effects of compounds 1 and 2 on human colorectal carcinoma cells (HCT116), non-small cell lung carcinoma cells (A549) and hepatic cancer cells (SMMC-7721) were evaluated. The results showed that both compounds 1 and 2 significantly inhibited the viability, proliferation, and migration of A549, HCT116 and SMMC-7721 cells, suggesting that compounds 1 and 2 can be applied in the treatment of lung, colon and liver cancers in clinical practice. This study may not only provide a scientific basis for clarifying the active ingredients in A. curassavica, but also help to understand its antitumor activity, which can promote the application of A. curassavica in clinical treatment of various cancers.


Assuntos
Antineoplásicos , Asclepias , Antineoplásicos/farmacologia , Asclepias/química , Cardenolídeos/química , Cardenolídeos/farmacologia , Glicosídeos/química , Glicosídeos/farmacologia , Humanos , Sementes
17.
Phytochemistry ; 199: 113172, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35381277

RESUMO

Six unidentified C21 steroidal glycosides, cynwallosides A-F, as well as twenty-two known compounds, were isolated from the roots of Cynanchum wallichii Wight. The structures of cynwallosides A-F were determined by spectroscopic analysis and acidic hydrolysis. Most of these twenty-eight compounds were found to significantly reverse drug resistance in both the MCF-7/ADR and HepG2/ADM cell lines by suppressing P-gp protein expression. Further investigation revealed that three compounds suppressed P-gp expression by significantly inactivating the JNK and NF-κB pathways.


Assuntos
Cynanchum , Cynanchum/química , Resistência a Múltiplos Medicamentos , Glicosídeos/química , Imidazóis , Estrutura Molecular , Raízes de Plantas/química , Pregnanos/química , Pregnanos/farmacologia , Sulfonamidas , Tiofenos
18.
Innovation (Camb) ; 3(2): 100221, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35252935

RESUMO

The highly pathogenic and readily transmissible SARS-CoV-2 has caused a global coronavirus pandemic, urgently requiring effective countermeasures against its rapid expansion. All available vaccine platforms are being used to generate safe and effective COVID-19 vaccines. Here, we generated a live-attenuated candidate vaccine strain by serial passaging of a SARS-CoV-2 clinical isolate in Vero cells. Deep sequencing revealed the dynamic adaptation of SARS-CoV-2 in Vero cells, resulting in a stable clone with a deletion of seven amino acids (N679SPRRAR685) at the S1/S2 junction of the S protein (named VAS5). VAS5 showed significant attenuation of replication in multiple human cell lines, human airway epithelium organoids, and hACE2 mice. Viral fitness competition assays demonstrated that VAS5 showed specific tropism to Vero cells but decreased fitness in human cells compared with the parental virus. More importantly, a single intranasal injection of VAS5 elicited a high level of neutralizing antibodies and prevented SARS-CoV-2 infection in mice as well as close-contact transmission in golden Syrian hamsters. Structural and biochemical analysis revealed a stable and locked prefusion conformation of the S trimer of VAS5, which most resembles SARS-CoV-2-3Q-2P, an advanced vaccine immunogen (NVAX-CoV2373). Further systematic antigenic profiling and immunogenicity validation confirmed that the VAS5 S trimer presents an enhanced antigenic mimic of the wild-type S trimer. Our results not only provide a potent live-attenuated vaccine candidate against COVID-19 but also clarify the molecular and structural basis for the highly attenuated and super immunogenic phenotype of VAS5.

19.
J Med Virol ; 94(7): 3223-3232, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35322439

RESUMO

SARS-CoV-2 has evolved into a panel of variants of concern (VOCs) and constituted a sustained threat to global health. The wildtype (WT) SARS-CoV-2 isolates fail to infect mice, while the Beta variant, one of the VOCs, has acquired the capability to infect standard laboratory mice, raising a spreading risk of SARS-CoV-2 from humans to mice. However, the infectivity and pathogenicity of other VOCs in mice remain not fully understood. In this study, we systematically investigated the infectivity and pathogenicity of three VOCs, Alpha, Beta, and Delta, in mice in comparison with two well-understood SARS-CoV-2 mouse-adapted strains, MASCp6 and MASCp36, sharing key mutations in the receptor-binding domain (RBD) with Alpha or Beta, respectively. Our results showed that the Beta variant had the strongest infectivity and pathogenicity among the three VOCs, while the Delta variant only caused limited replication and mild pathogenic changes in the mouse lung, which is much weaker than what the Alpha variant did. Meanwhile, Alpha showed comparable infectivity in lungs in comparison with MASCp6, and Beta only showed slightly lower infectivity in lungs when compared with MASCp36. These results indicated that all three VOCs have acquired the capability to infect mice, highlighting the ongoing spillover risk of SARS-CoV-2 from humans to mice during the continued evolution of SARS-CoV-2, and that the key amino acid mutations in the RBD of mouse-adapted strains may be referenced as an early-warning indicator for predicting the spillover risk of newly emerging SARS-CoV-2 variants.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , Camundongos , Ligação Proteica , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/metabolismo
20.
J Agric Food Chem ; 70(13): 4000-4006, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35297245

RESUMO

Six unusual meroterpenoids, psidiguajadiol A-J (1-6), and three known meroterpenoids (7-9) were isolated from the leaves of Psidium guajava L. Compounds 2-6 represent the first examples of 6/8-formyl-5,7-dihydroxy-4-phenylchromane-coupled sesquiterpenoids. The structures of the undescribed compounds, including their absolute configurations, were elucidated by spectroscopic analyses, X-ray diffraction, and computational calculations. Compounds 3, 4, and 6 exhibited inhibitory activities against PTP1B with IC50 values of 9.83, 18.52, and 16.87 µM, respectively. In light of these findings, we performed molecular docking studies to predict their inhibition mechanisms at the atomic level.


Assuntos
Psidium , Sesquiterpenos , Simulação de Acoplamento Molecular , Folhas de Planta/química , Psidium/química , Sesquiterpenos/química , Análise Espectral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...