Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 548
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
PLoS Pathog ; 19(10): e1011702, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37801439

RESUMO

Coronaviruses (CoVs) are a family of the largest RNA viruses that typically cause respiratory, enteric, and hepatic diseases in animals and humans, imposing great threats to the public safety and animal health. Porcine deltacoronavirus (PDCoV), a newly emerging enteropathogenic coronavirus, causes severe diarrhea in suckling piglets all over the world and poses potential risks of cross-species transmission. Here, we use PDCoV as a model of CoVs to illustrate the reciprocal regulation between CoVs infection and host antiviral responses. In this study, downregulation of DNA polymerase delta interacting protein 3 (POLDIP3) was confirmed in PDCoV infected IPEC-J2 cells by isobaric tags for relative and absolute quantification (iTRAQ) and Western blotting analysis. Overexpression of POLDIP3 inhibits PDCoV infection, whereas POLDIP3 knockout (POLDIP3-/-) by CRISPR-Cas9 editing significantly promotes PDCoV infection, indicating POLDIP3 as a novel antiviral regulator against PDCoV infection. Surprisingly, an antagonistic strategy was revealed that PDCoV encoded nonstructural protein 5 (nsp5) was responsible for POLDIP3 reduction via its 3C-like protease cleavage of POLDIP3 at the glutamine acid 176 (Q176), facilitating PDCoV infection due to the loss of antiviral effects of the cleaved fragments. Consistent with the obtained data in IPEC-J2 cell model in vitro, POLDIP3 reduction by cleavage was also corroborated in PDCoV infected-SPF piglets in vivo. Collectively, we unveiled a new antagonistic strategy evolved by PDCoV to counteract antiviral innate immunity by nsp5-mediated POLDIP3 cleavage, eventually ensuring productive virus replication. Importantly, we further demonstrated that nsp5s from PEDV and TGEV harbor the conserved function to cleave porcine POLDIP3 at the Q176 to despair POLDIP3-mediated antiviral effects. In addition, nsp5 from SARS-CoV-2 also cleaves human POLDIP3. Therefore, we speculate that coronaviruses employ similar POLDIP3 cleavage mechanisms mediated by nsp5 to antagonize the host antiviral responses to sustain efficient virus infection.


Assuntos
Infecções por Coronavirus , Doenças dos Suínos , Animais , Humanos , Suínos , Imunidade Inata , Replicação Viral , Antivirais , Proteínas de Ligação a RNA
2.
Proc Natl Acad Sci U S A ; 119(20): e2120870119, 2022 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-35544691

RESUMO

Transient receptor potential canonical 4 (TRPC4) is a receptor-operated cation channel codependent on both the Gq/11­phospholipase C signaling pathway and Gi/o proteins for activation. This makes TRPC4 an excellent coincidence sensor of neurotransmission through Gq/11- and Gi/o-coupled receptors. In whole-cell slice recordings of lateral septal neurons, TRPC4 mediates a strong depolarizing plateau that shuts down action potential firing, which may or may not be followed by a hyperpolarization that extends the firing pause to varying durations depending on the strength of Gi/o stimulation. We show that the depolarizing plateau is codependent on Gq/11-coupled group I metabotropic glutamate receptors and on Gi/o-coupled γ-aminobutyric acid type B receptors. The hyperpolarization is mediated by Gi/o activation of G protein­activated inwardly rectifying K+ (GIRK) channels. Moreover, the firing patterns, elicited by either electrical stimulation or receptor agonists, encode information about the relative strengths of Gq/11 and Gi/o inputs in the following fashion. Pure Gq/11 input produces weak depolarization accompanied by firing acceleration, whereas pure Gi/o input causes hyperpolarization that pauses firing. Although coincident Gq/11­Gi/o inputs also pause firing, the pause is preceded by a burst, and both the pause duration and firing recovery patterns reflect the relative strengths of Gq/11 versus Gi/o inputs. Computer simulations demonstrate that different combinations of TRPC4 and GIRK conductances are sufficient to produce the range of firing patterns observed experimentally. Thus, concurrent neurotransmission through the Gq/11 and Gi/o pathways is converted to discernible electrical responses by the joint actions of TRPC4 and GIRK for communication to downstream neurons.


Assuntos
Potenciais de Ação , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP , Subunidades alfa de Proteínas de Ligação ao GTP , Neurônios , Transmissão Sináptica , Canais de Cátion TRPC , Animais , Comunicação Celular , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/fisiologia , Subunidades alfa de Proteínas de Ligação ao GTP/fisiologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Camundongos , Neurônios/fisiologia , Canais de Cátion TRPC/fisiologia
3.
Mol Cancer ; 23(1): 15, 2024 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-38225603

RESUMO

Mounting evidence suggests a strong association between tumor immunity and epigenetic regulation. The histone-lysine N-methyltransferase 2 (KMT2) family plays a crucial role in the methylation of histone H3 at lysine 4. By influencing chromatin structure and DNA accessibility, this modification serves as a key regulator of tumor progression and immune tolerance across various tumors. These findings highlight the potential significance of the KMT2 family in determining response to immune checkpoint inhibitor (ICI) therapy, which warrants further exploration. In this study, we integrated four ICI-treated cohorts (n = 2069) across 10 cancer types and The Cancer Genome Atlas pan-cancer cohort and conducted a comprehensive clinical and bioinformatic analysis. Our study indicated that patients with KMT2 family gene mutations benefited more from ICI therapy in terms of overall survival (P < 0.001, hazard ratio [HR] = 0.733 [95% confidence interval (CI): 0.632-0.850]), progression-free survival (P = 0.002, HR = 0.669 [95% CI: 0.518-0.864]), durable clinical benefit (P < 0.001, 54.1% vs. 32.6%), and objective response rate (P < 0.001, 40.6% vs. 22.0%). Through a comprehensive analysis of the tumor microenvironment across different KMT2 mutation statuses, we observed that tumors harboring the KMT2 mutation exhibited enhanced immunogenicity, increased infiltration of immune cells, and higher levels of immune cell cytotoxicity, suggesting a propensity towards a "hot tumor" phenotype. Therefore, our study indicates a potential association between KMT2 mutations and a more favorable response to ICI therapy and implicates different tumor microenvironments associated with ICI therapy response.


Assuntos
Epigênese Genética , Neoplasias , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Microambiente Tumoral , Mutação , Neoplasias/tratamento farmacológico , Neoplasias/genética
4.
J Virol ; 97(2): e0187122, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36648234

RESUMO

Pseudorabies virus (PRV) is a neurotropic virus causing obvious neurological disorders and reproductive failure in pigs. PRV entry into target cells is a complex multistep process initiated by interacting viral envelope glycoproteins with cellular receptors. In the current study, we found that thrombospondin 3 (THBS3) plays an important role in PRV entry into target cells, indicating that THBS3 is a new PRV coreceptor. To confirm this hypothesis, the knockdown of THBS3 in several permissive cells inhibited PRV primary infection, and overexpression of THBS3 in PK15 cells promoted PRV infection. CRISPR-Cas9 knockout markedly reduced PRV infection in PK15 cells. Antibodies against THBS3 blocked PRV infection in naturally permissive target cells. Moreover, soluble THBS3 protein neutralized the infectivity of PRV. Mechanistically, THBS3 interacted with the PRV gD via its N and C termini to facilitate PRV binding in permissive and nonpermissive cells. Also, in the absence of Nectin-1, THBS3 promoted cell-to-cell fusion mediated by virus glycoproteins. While THBS3 alone could not increase virus entry, overexpression of it in the presence of Nectin-1 promoted virus entry into CHO-K1 cells. Our results have identified THBS3 as a critical player in PRV binding and subsequent membrane fusion and entry. IMPORTANCE Herpesvirus entry occurs through a cascade of virus-cell interactions, and multiple surface glycoproteins play a role in virus binding and entry during the virus invasion process. Early studies showed that attachment to cells by PRV, as well as other alphaherpesviruses, is mediated by interactions between the viral glycoprotein gC and cell membrane proteoglycans carrying heparan sulfate chains (HSPGs). However, gD may also be involved in virus binding in an HSPG-independent manner. To date, the respective cellular receptors are still unknown. In this report, we identified a host molecule, THBS3, involved in gD-mediated PRV binding and subsequent membrane fusion and entry, which increases our understanding of the initial events in alpha herpesvirus infections.


Assuntos
Herpesvirus Suídeo 1 , Pseudorraiva , Ligação Viral , Internalização do Vírus , Animais , Cricetinae , Células CHO , Herpesvirus Suídeo 1/metabolismo , Herpesvirus Suídeo 1/patogenicidade , Nectinas/genética , Nectinas/metabolismo , Suínos , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Técnicas de Silenciamento de Genes
5.
Chemistry ; 30(19): e202304081, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38288909

RESUMO

Optically pure sulfoxides are valuable organosulfur compounds extensively employed in medicinal and organic synthesis. In this study, we present a biocatalytic oxidation-reduction cascade system designed for the preparation of enantiopure sulfoxides. The system involves the cooperation of a low-enantioselective chimeric oxidase SMO (styrene monooxygenase) with a high-enantioselective reductase MsrA (methionine sulfoxide reductase A), facilitating "non-selective oxidation and selective reduction" cycles for prochiral sulfide oxidation. The regeneration of requisite cofactors for MsrA and SMO was achieved via a cascade catalysis process involving three auxiliary enzymes, sustained by cost-effective D-glucose. Under the optimal reaction conditions, a series of heteroaryl alkyl, aryl alkyl and dialkyl sulfoxides in R configuration were synthesized through this "one-pot, one step" cascade reaction. The obtained compounds exhibited high yields of >90 % and demonstrated enantiomeric excess (ee) values exceeding 90 %. This study represents an unconventional and efficient biocatalytic way in utilizing the low-enantioselective oxidase for the synthesis of enantiopure sulfoxides.


Assuntos
Metionina Sulfóxido Redutases , Sulfóxidos , Biocatálise , Oxirredução , Catálise , Estereoisomerismo
6.
BMC Urol ; 24(1): 17, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38238690

RESUMO

BACKGROUND: To demonstrate the technical feasibility of percutaneous nephrolithotomy (PCNL) guided by 5G-powered robot-assisted teleultrasound diagnosis system (RTDS) in a complex kidney-stone (CKS) cohort and present our preliminary outcomes. PCNL is highly skill-required, which hinders it popularization in primary medical units of remote regions. We designed an innovative tele-assistance approach to make PCNL easy to be operated by inexperienced surgeons. METHODS: This was a prospective proof-of-concept study (IDEAL phase 1) on intraoperative tele-assistance provided by online urological experts via a 5G-powered RTDS. Total 15 CKS patients accepted this technology. Online experts manipulated a simulated probe to assist unskilled local operators by driving a patient-side robot-probe to guide and monitor the steps of access establishment and finding residual stones. RESULTS: Median total delay was 177ms despite one-way network-connecting distance > 5,800 km. No perceptible delay of audio-visual communication, driving robot-arm or dynamic ultrasound images was fed back. Successful tele-assistance was obtained in all cases. The first-puncture access-success rate was 78.6% with a one-session SF rate of 71.3% and without complications of grade III-V. CONCLUSIONS: The current technology based on 5G-powered RTDS can provide high-quality intraoperative tele-assistance, which has preliminarily shown satisfactory outcomes and reliable safety. It will break down a personal competence-based barrier to endow PCNL with more popular utilization. TRIAL REGISTRATION: The study was approved by ethics committee of the Xinjiang Kezhou People's Hospital and ethics committee of the First Affiliated Hospital of Nanjing Medical University and was registered on http://www.chictr.org.cn (ChiCTR2200065849, 16/11/2022).


Assuntos
Cálculos Renais , Metacrilatos , Nefrolitotomia Percutânea , Nefrostomia Percutânea , Robótica , Humanos , Nefrolitotomia Percutânea/métodos , Estudos Prospectivos , Resultado do Tratamento , Cálculos Renais/diagnóstico por imagem , Cálculos Renais/cirurgia , Nefrostomia Percutânea/métodos
7.
J Am Chem Soc ; 145(49): 26550-26556, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38019148

RESUMO

A catalytic enantioselective polycyclization of tertiary enamides with terminal silyl enol ethers has been developed by virtue of Cu(OTf)2 catalysis with a novel spiropyrroline-derived oxazole (SPDO) ligand. This tandem reaction offers an effective approach to assemble bicyclic and tricyclic N-heterocycles bearing both aza- and oxa-quaternary stereogenic centers, which are primal subunits in a range of natural alkaloids. Strategic application of this methodology and a late-stage radical cyclization as key steps have been showcased in the concise total synthesis of (-)-cephalocyclidin A.

8.
Anal Chem ; 95(18): 7237-7243, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37120835

RESUMO

DNA nanosheets (DNSs) have been utilized effectively as a fluorescence anisotropy (FA) amplifier for biosensing. But, their sensitivity needs to be further improved. Herein, CRISPR-Cas12a with strong trans-cleavage activity was utilized to enhance the FA amplification ability of DNSs for the sensitive detection of miRNA-155 (miR-155) as a proof-of-principle target. In this method, the hybrid of the recognition probe of miR-155 (T1) and a blocker sequence (T2) was immobilized on the surface of magnetic beads (MBs). In the presence of miR-155, T2 was released by a strand displacement reaction, which activated the trans-cleavage activity of CRISPR-Cas12a. The single-stranded DNA (ssDNA) probe modified with a carboxytetramethylrhodamine (TAMRA) fluorophore was cleaved in large quantities and could not bind to the handle chain on DNSs, inducing a low FA value. In contrast, in the absence of miR-155, T2 could not be released and the trans-cleavage activity of CRISPR-Cas12a could not be activated. The TAMRA-modified ssDNA probe remained intact and was complementary to the handle chain on the DNSs, and a high FA value was obtained. Thus, miR-155 was detected through the obviously decreased FA value with a low limit of detection (LOD) of 40 pM. Impressively, the sensitivity of this method was greatly improved about 322 times by CRISPR-Cas12a, confirming the amazing signal amplification ability of CRISPR-Cas12a. At the same time, the SARS-CoV-2 nucleocapsid protein was detected by the strategy successfully, indicating that this method was general. Moreover, this method has been applied in the analysis of miR-155 in human serum and the lysates of cells, which provides a new avenue for the sensitive determination of biomarkers in biochemical research and disease diagnosis.


Assuntos
Técnicas Biossensoriais , COVID-19 , MicroRNAs , Humanos , SARS-CoV-2 , DNA , DNA de Cadeia Simples , Sistemas CRISPR-Cas/genética
9.
Cancer Immunol Immunother ; 72(7): 1957-1969, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36811662

RESUMO

BACKGROUND AND AIMS: The impacts of macrovascular invasion (MVI) or extrahepatic spread (EHS) on the efficacy and safety of immune checkpoint inhibitors (ICIs) among hepatocellular carcinoma (HCC) patients remain unclear. Thus, we conducted a systematic review and meta-analysis to clarify whether ICI therapy is a feasible treatment option for HCC with MVI or EHS. METHODS: Eligible studies published before September 14, 2022, were retrieved. In this meta-analysis, the objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and occurrence of adverse events (AEs) were outcomes of interest. RESULTS: Fifty-four studies involving 6187 individuals were included. The findings indicated that the presence of EHS in ICI-treated HCC patients may indicate an inferior ORR (OR 0.77, 95% CI 0.63-0.96), but may not significantly affect the PFS (multivariate analyses: HR 1.27, 95% CI 0.70-2.31) and OS (multivariate analyses: HR 1.23, 95% CI 0.70-2.16). Additionally, the presence of MVI in ICI-treated HCC patients may not have significant prognostic impact on ORR (OR 0.84, 95% CI 0.64-1.10), but may indicate inferior PFS (multivariate analyses: HR 1.75, 95% CI 1.07-2.84) and OS (multivariate analyses: HR 2.03, 95% CI 1.31-3.14). The presence of EHS or MVI in ICI-treated HCC patients may not significantly impact the occurrence of any serious immune-related adverse events (irAEs) (grades ≥ 3) (EHS: OR 0.44, 95% CI 0.12-1.56; MVI: OR 0.68, 95% CI 0.24-1.88). CONCLUSION: The presence of MVI or EHS in ICI-treated HCC patients may not significantly impact the occurrence of serious irAEs. However, the presence of MVI (but not EHS) in ICI-treated HCC patients may be a significant negative prognostic factor. Therefore, ICI-treated HCC patients with MVI warrant more attention.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Inibidores de Checkpoint Imunológico/efeitos adversos , Neoplasias Hepáticas/patologia , Prognóstico
10.
J Virol ; 96(5): e0088921, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-34495699

RESUMO

Porcine epidemic diarrhea virus (PEDV) causes a porcine disease associated with swine epidemic diarrhea. Different antagonistic strategies have been identified, and the mechanism by which PEDV infection impairs the production of interferon (IFN) and delays the activation of the IFN response to escape host innate immunity has been determined, but the pathogenic mechanisms of PEDV infection remain enigmatic. Our preliminary results revealed that endogenous F-box and WD repeat domain-containing 7 (FBXW7) protein, the substrate recognition component of the SCF-type E3 ubiquitin ligase, is downregulated in PEDV-infected Vero E6 cells, according to the results from an isobaric tags for relative and absolute quantification (iTRAQ) analysis. Overexpression of FBXW7 in target cells makes them more resistant to PEDV infection, whereas ablation of FBXW7 expression by small interfering RNA (siRNA) significantly promotes PEDV infection. In addition, FBXW7 was verified as an innate antiviral factor capable of enhancing the expression of RIG-I and TBK1, and it was found to induce interferon-stimulated genes (ISGs), which led to an elevated antiviral state of the host cells. Moreover, we revealed that PEDV nonstructural protein 2 (nsp2) interacts with FBXW7 and targets FBXW7 for degradation through the K48-linked ubiquitin-proteasome pathway. Consistent with the results proven in vitro, FBXW7 reduction was also confirmed in different intestinal tissues from PEDV-infected specific-pathogen-free (SPF) pigs. Taken together, the data indicated that PEDV has evolved with a distinct antagonistic strategy to circumvent the host antiviral response by targeting the ubiquitin-proteasome-mediated degradation of FBXW7. Our findings provide novel insights into PEDV infection and pathogenesis. IMPORTANCE To counteract the host antiviral defenses, most viruses, including coronaviruses, have evolved with diverse strategies to dampen host IFN-mediated antiviral response, by interfering with or evading specific host regulators at multiple steps of this response. In this study, a novel antagonistic strategy was revealed showing that PEDV infection could circumvent the host innate response by targeted degradation of endogenous FBXW7 in target cells, a process that was verified to be a positive modulator for the host innate immune system. Degradation of FBXW7 hampers host innate antiviral activation and facilitates PEDV replication. Our findings reveal a new mechanism exploited by PEDV to suppress the host antiviral response.


Assuntos
Infecções por Coronavirus/veterinária , Proteína 7 com Repetições F-Box-WD/metabolismo , Evasão da Resposta Imune , Imunidade Inata , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/imunologia , Animais , Antivirais/imunologia , Chlorocebus aethiops , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Interferon Tipo I/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais/imunologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Ubiquitinas/metabolismo , Células Vero
11.
Opt Express ; 31(20): 33123-33131, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859099

RESUMO

Large-area, highly uniform microwave field radiation and efficient excitation of fluorescence are the key to achieving high sensitivity sensing of the NV (nitrogen-vacancy) magnetometer. In this paper, we report a compact multipass-laser-beam antenna for NV ensemble color centers sensing. The antenna not only provides a tridimensional uniform magnetic field, but also can be used for efficient excitation of the NV fluorescence. The optimal size of the antenna and the angle of laser incidence are determined by the multi-physics field simulation software COMSOL. For an equivalent excitation power, the designed structure increases the path length of the excitation beam by up to three orders of magnitude, up to the level of m, compared to the conventional direct beam mode. Finally, this method increased the sensitivity by a factor of 60 realized a magnetic field sensitivity of 2.8 nT/√Hz in the range of 10-100 Hz. This work provides an experimental method for the design of integrated NV magnetometers.

12.
Anal Biochem ; 660: 114980, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36368345

RESUMO

A precolumn derivatization-HPLC method using 2,4-dinitrophenylhydrazine and 4-nitro-o-phenylenediamine as respective labeling reagents for comprehensive analyses of the reactions catalyzed by acetohydroxyacid synthase (AHAS)/acetolactate synthase (ALS) is developed and evaluated in this research. Comparison with the classic Bauerle' UV assay which can analyze the enzymes only through measurement of acetoin production, the HPLC method shows advantages because it can analyze the enzymes not only via determination of consumption of the substrate pyruvate, but also via measurement of formation of the products including acetoin, 2,3-butanedione, and acetaldehyde in the enzymatic reactions. Thus the results deduced from the HPLC method can reflect the trait of each enzyme in a more precise manner. As far as we know, this is the first time that the reactions mediated by AHAS/ALS using pyruvate as a single substrate are globally analyzed and the features of the enzymes are properly discussed.


Assuntos
Acetolactato Sintase , Acetoína , Cromatografia Líquida de Alta Pressão , Ácido Pirúvico , Catálise
13.
J Org Chem ; 88(20): 14670-14675, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37815481

RESUMO

An asymmetric [3+2] cycloaddition of quinone esters with 2,3-dihydrofuran has been realized via a newly developed Cu(II)/SPDO complex. It provides straightforward access to 2,3,3a,8a-tetrahydrofuro[2,3-b]benzofurans (TFB) with high enantioselectivity (up to 97.5:2.5 er) and diastereoselectivity (all >20:1 dr). The resulting adducts contain two adjacent stereocenters and a continuously functionalized benzene ring. Additionally, this transformation could be easily performed on a gram scale, allowing for expedient synthesis of natural dihydroaflatoxin D2 and aflatoxin B2.

14.
Org Biomol Chem ; 21(16): 3417-3422, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-37017279

RESUMO

Optically pure sulfoxides are noteworthy compounds that find wide applications in various industrial fields. Here, we report a methionine sulfoxide reductase B (MsrB) homologue that exhibits high enantioselectivity and broad substrate scope for the kinetic resolution of racemic (rac) sulfoxides. This MsrB homologue, named liMsrB, was identified from Limnohabitans sp. 103DPR2 and showed good activity together with enantioselectivity towards a series of aromatic, heteroaromatic, alkyl and thioalkyl sulfoxides. Chiral sulfoxides in the S configuration were prepared in approximately 50% yield and 92-99% enantiomeric excess through kinetic resolution at an initial substrate concentration of up to 90 mM (11.2 g L-1). This study presents an efficient route for the enzymatic preparation of (S)-sulfoxides through kinetic resolution.


Assuntos
Metionina Sulfóxido Redutases , Sulfóxidos , Sulfóxidos/química , Cinética , Estereoisomerismo , Metionina
15.
Bioorg Chem ; 134: 106458, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36933336

RESUMO

Six new oligostilbenes, carastilphenols A-E (1-5) and (-)-hopeachinol B (6), with three reported oligostilbenes were obtained from the stems of Caragana sinica. The structures of compounds 1-6 were determined by comprehensive spectroscopy analysis, and their absolute configurations were determined by electronic circular dichroism calculations. Thus, natural tetrastilbenes were determined as absolute configuration for the first time. Also, we did several pharmacological essays. In the antiviral tests, compounds 2, 4 and 6 showed moderate anti-coxsackie virus B3 type (CVB3) effect on Vero cells activities in vitro with IC50 values of 19.2 âˆ¼ 69.3 µM; and compounds 3 and 4 showed different levels of anti-respiratory syncytial virus (RSV) effect on Hep2 cells activities in vitro with IC50 values of 23.1 and 33.3 µM, respectively. As for hypoglycemic activity, compounds 6-9 (10 µM) showed the inhibition of α-glucosidase in vitro with IC50 values of 0.1 âˆ¼ 0.4 µM; and compound 7 showed significant inhibition (88.8%, 10 µM) of protein tyrosine phosphatase 1B (PTP1B) with IC50 value of 1.1 µM in vitro.


Assuntos
Caragana , Hipoglicemiantes , Animais , Chlorocebus aethiops , Hipoglicemiantes/farmacologia , Hipoglicemiantes/química , Caragana/química , Caragana/metabolismo , Células Vero , Antivirais/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1 , Estrutura Molecular
16.
Bioorg Chem ; 135: 106491, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37011521

RESUMO

PTP1B plays an important role as a key negative regulator of tyrosine phosphorylation associated with insulin receptor signaling in the therapy for diabetes and obesity. In this study, the anti-diabetic activity of dianthrone derivatives from Polygonum multiflorum Thunb., as well as the structure-activity relationships, mechanism, and molecular docking were explored. Among these analogs, trans-emodin dianthrone (compound 1) enhances insulin sensitivity by upregulating the insulin signaling pathway in HepG2 cells and displays considerable anti-diabetic activity in db/db mice. By using photoaffinity labeling and mass spectrometry-based proteomics, we discovered that trans-emodin dianthrone (compound 1) may bind to PTP1B allosteric pocket at helix α6/α7, which provides fresh insight into the identification of novel anti-diabetic agents.


Assuntos
Diabetes Mellitus , Emodina , Fallopia multiflora , Camundongos , Animais , Fallopia multiflora/química , Fallopia multiflora/metabolismo , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo
17.
Ecotoxicol Environ Saf ; 268: 115732, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38000301

RESUMO

Glutathione plays a critical role in plant growth, development and response to stress. It is a major cellular antioxidant and is involved in the detoxification of xenobiotics in many organisms, including plants. However, the role of glutathione-dependent redox homeostasis and associated molecular mechanisms regulating the antioxidant system and pesticide metabolism remains unclear. In this study, endogenous glutathione levels were manipulated by pharmacological treatments with glutathione synthesis inhibitors and oxidized glutathione. The application of oxidized glutathione enriched the cellular oxidation state, reduced the activity and transcript levels of antioxidant enzymes, upregulated the expression level of nitric oxide and Ca2+ related genes and the content, and increased the residue of chlorothalonil in tomato leaves. Further experiments confirmed that glutathione-induced redox homeostasis is critical for the reduction of pesticide residues. RNA sequencing analysis revealed that miRNA156 and miRNA169 that target transcription factor SQUAMOSA-Promoter Binding Proteins (SBP) and NUCLEAR FACTOR Y (NFY) potentially participate in glutathione-mediated pesticide degradation in tomato plants. Our study provides important clues for further dissection of pesticide degradation mechanisms via miRNAs in plants.


Assuntos
Praguicidas , Solanum lycopersicum , Antioxidantes/metabolismo , Solanum lycopersicum/genética , Dissulfeto de Glutationa/metabolismo , Glutationa/metabolismo , Oxirredução , Praguicidas/metabolismo , Plantas/metabolismo , Homeostase , Estresse Oxidativo
18.
Sensors (Basel) ; 23(12)2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37420640

RESUMO

With the development of 3D sensors technology, 3D point cloud is widely used in industrial scenes due to their high accuracy, which promotes the development of point cloud compression technology. Learned point cloud compression has attracted much attention for its excellent rate distortion performance. However, there is a one-to-one correspondence between the model and the compression rate in these methods. To achieve compression at different rates, a large number of models need to be trained, which increases the training time and storage space. To address this problem, a variable rate point cloud compression method is proposed, which enables the adjustment of the compression rate by the hyperparameter in a single model. To address the narrow rate range problem that occurs when the traditional rate distortion loss is jointly optimized for variable rate models, a rate expansion method based on contrastive learning is proposed to expands the bit rate range of the model. To improve the visualization effect of the reconstructed point cloud, a boundary learning method is introduced to improve the classification ability of the boundary points through boundary optimization and enhance the overall model performance. The experimental results show that the proposed method achieves variable rate compression with a large bit rate range while ensuring the model performance. The proposed method outperforms G-PCC, achieving more than 70% BD-Rate against G-PCC, and performs about, as well as the learned methods at high bit rates.


Assuntos
Compressão de Dados , Fenômenos Físicos , Indústrias , Aprendizagem , Tecnologia
19.
Zhongguo Zhong Yao Za Zhi ; 48(22): 6216-6224, 2023 Nov.
Artigo em Zh | MEDLINE | ID: mdl-38114228

RESUMO

This study aims to systematically review the efficacy and safety of Shufeng Jiedu Capsules in the treatment of influenza. The randomized controlled trial(RCT) of Shufeng Jiedu Capsules alone or in combination with conventional western medicine for treating influenza were retrieved from PubMed, EMbase, Cochrane Library, Web of Science, SinoMed, CNKI, VIP, Wanfang, and ClinicalTrails.gov. The data analysis was performed in RevMan 5.4.1. The Cochrane risk of bias assessment tool was used to evaluate the quality of the involved RCT, and GRADEpro GDT to assess the quality of the evidence. A total of 11 RCTs involving 1 836 patients were included in this study. Compared with conventional western medicine, Shufeng Jiedu Capsules/Shufeng Jiedu Capsules + conventional western medicine improved the response rate(RR=1.09, 95%CI[1.03, 1.15], P=0.002), shortened the time to relief of cough, and increased the 3-day sore throat relief rate, whereas there was no significant difference in the time to fever abatement, the time to relief of sore throat, 3-day cough relief rate, or 3-day runny nose relief rate. Subgroup-analysis showed that Shufeng Jiedu Capsules + conventional western medicine improved the response rate(RR=1.11, 95%CI[1.08, 1.15], P<0.000 01), shortened the time to relief of cough, and increased the 3-day relief rate of symptoms(cough, sore throat, and runny nose) compared with conventional western medicine alone, while there was no significant difference in the time to fever abatement or the time to relief of sore throat. Shufeng Jiedu Capsules alone could not improve the response rate(RR=0.97, 95%CI[0.93, 1.02], P=0.19). In addition, Shufeng Jiedu Capsules/Shufeng Jiedu Capsules + conventional western medicine vs conventional western medicine were no significant difference in adverse reactions(RR=0.98, 95%CI[0.57, 1.69], P=0.95). The available evidence suggests that Shufeng Jiedu Capsules is effective and safe in the treatment of influenza, and the combination of Shufeng Jiedu Capsules with conventional western medicine can accelerate the relief of symptoms. However, since the number and quality of the included studies were low, the above findings remained to be further verified by multicenter RCT with large sample sizes.


Assuntos
Medicamentos de Ervas Chinesas , Influenza Humana , Faringite , Humanos , Influenza Humana/tratamento farmacológico , Medicamentos de Ervas Chinesas/efeitos adversos , Cápsulas , Tosse/tratamento farmacológico , Tosse/induzido quimicamente , Rinorreia , Estudos Multicêntricos como Assunto
20.
Angew Chem Int Ed Engl ; 62(39): e202308858, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37462217

RESUMO

An asymmetric intramolecular hydroalkylation of unactivated internal olefins with tethered cyclic ketones was realized by the cooperative catalysis of a newly designed chiral amine (SPD-NH2 ) and PdII complex, providing straightforward access to either bridged or fused bicyclic systems containing three stereogenic centers with excellent enantioselectivity (up to 99 % ee) and diastereoselectivity (up to >20 : 1 dr). Notably, the bicyclic products could be conveniently transformed into a diverse range of key structures frequently found in bioactive terpenes, such as Δ6 -protoilludene, cracroson D, and vulgarisins. The steric hindrance between the Ar group of the SPD-NH2 catalyst and the branched chain of the substrate, hydrogen-bonding interactions between the N-H of the enamine motif and the C=O of the directing group MQ, and the counterion of the PdII complex were identified as key factors for excellent stereoinduction in this dual catalytic process by density functional theory calculations.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA