RESUMO
Invertebrates mainly rely on sequence-specific RNA interference (RNAi) to resist viral infections. Increasing studies show that double-stranded RNA (dsRNA) can induce sequence-independent protection and that Dicer-2, the key RNAi player that cleaves long dsRNA into small interfering RNA (siRNA), is necessary for this protection. However, how this protection occurs remains unknown. Herein, we report that it is caused by adenosine triphosphate (ATP)-hydrolysis accompanying the dsRNA-cleavage. Dicer-2 helicase domain is ATP-dependent; therefore, the cleavage consumes ATP. ATP depletion activates adenosine monophosphate-activated protein kinase (Ampk) and induces nuclear localization of Fork head box O (FoxO), a key transcriptional factor for dsRNA-induced genes. siRNAs that do not require processing cannot activate the transcriptional response. This study reveals a unique nonspecific antiviral mechanism other than the specific RNAi in shrimp. This mechanism is functionally similar to, but mechanistically different from, the dsRNA-activated antiviral response in vertebrates and suggests an interesting evolution of innate antiviral immunity.
Assuntos
Proteínas Quinases Ativadas por AMP , Trifosfato de Adenosina , RNA de Cadeia Dupla , Ribonuclease III , Animais , RNA de Cadeia Dupla/metabolismo , Ribonuclease III/metabolismo , Ribonuclease III/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Imunidade Inata , Transcrição GênicaRESUMO
Alkene functionalisation is a powerful strategy that has enabled access to a wide array of compounds including valuable pharmaceuticals and agrochemicals. The reactivity of the alkene π-bond has allowed incorporation of a diverse range of atoms and functional groups through a wide variety of reaction pathways. N-Heterocyclic carbenes (NHCs) are a class of persistent carbenes that are widely employed as ancillary ligands due to their ability to act as strong σ-donors compared to widely-applied conventional phosphine-based ligands. NHCs are also unique as their molecular bulk provides steric influence for regio- and stereo-control in many alkene functionalisation reactions, illustrated by the examples covered in this review. A combination of the unique reactivity of NHC ligands and nickel's characteristics has facilitated the design of reaction pathways that show distinct selectivity and reactivity, including the activation of bonds previously considered "inert", such as C-H bonds, the C-O bond of ethers and esters, and the C-N bonds of amides. This review summarises the advancements in Ni(NHC) catalysed alkene functionalisation up to 2022, covering the following major reaction classes: Heck-type reactions, hydrofunctionalisation and dicarbofunctionalisation.
RESUMO
This study was carried out to investigate the correlation between the onset of peripheral neuropathy and levels of hypersensitive C-reactive protein (hs-CRP), interleukin 1ß (IL-1ß) and IL-6 in senile Parkinson's disease (PD) patients. For this purpose, a total of 60 PD patients and 60 age-matched healthy subjects were enrolled in this study and received the assessment for peripheral nerves by using the quantified method. Besides, levels of hs-CRP, IL-1ß and IL-6 in serum were determined to analyze the correlation between the clinical features, including the severity of PD and cognitive decline, and the levels of hs-CRP, IL-1ß and IL-6. Results showed that PD patients had more cases of peripheral neuropathy than those in the healthy control group. Levels of hs-CRP, IL-1ß and IL-6 in the serum of PD patients were much higher than those in the healthy control (P<0.05). Besides, PD patients had lower scores of MMSE and MoCA but higher CNPI scores when compared to the healthy control group. As a result, we found that the severity of peripheral neuropathy was in a positive correlation with the levels of hs-CRP, IL-1ß and IL-6. It was concluded that PD patients generally have peripheral neuropathy that may correlate with the increases in the levels of hs-CRP, IL-1ß and IL-6, and early intervention may mitigate the development and progression of peripheral neuropathy.
Assuntos
Doença de Parkinson , Doenças do Sistema Nervoso Periférico , Humanos , Proteína C-Reativa/metabolismo , Interleucina-1beta , Interleucina-6RESUMO
Zearalenone (ZEN) is a potent oestrogenic mycotoxin that is mainly produced by Fusarium species and is a serious environmental pollutant in animal feeds. Apiotrichum mycotoxinivorans has been widely used as a feed additive to detoxify ZEN. However, the effects of ZEN on A. mycotoxinivorans and its detoxification mechanisms remain unclear. In this study, transcriptomic and bioinformatic analyses were used to investigate the molecular responses of A. mycotoxinivorans to ZEN exposure and the genetic basis of ZEN detoxification. We detected 1424 significantly differentially expressed genes (DEGs), of which 446 were upregulated and 978 were downregulated. Functional and enrichment analyses showed that ZEN-induced genes were significantly associated with xenobiotic metabolism, oxidative stress response, and active transport systems. However, ZEN-inhibited genes were mainly related to cell division, cell cycle, and fungal development. Subsequently, bioinformatic analysis identified candidate ZEN-detoxification enzymes. The Baeyer-Villiger monooxygenases and carboxylesterases, which are responsible for the formation and subsequent hydrolysis of a new ZEN lactone, respectively, were significantly upregulated. In addition, the expression levels of genes related to conjugation and transport involved in the xenobiotic detoxification pathway were significantly upregulated. Moreover, the expression levels of genes encoding enzymatic antioxidants and those related to growth and apoptosis were significantly upregulated and downregulated, respectively, which made it possible for A. mycotoxinivorans to survive in a highly toxic environment and efficiently detoxify ZEN. This is the first systematic report of ZEN tolerance and detoxification in A. mycotoxinivorans. We identified the metabolic enzymes that were potentially involved in detoxifying ZEN in the GMU1709 strain and found that ZEN-induced transcriptional regulation of genes is key to withstanding highly toxic environments. Hence, our results provide valuable information for developing enzymatic detoxification systems or engineering this detoxification pathway in other species.
Assuntos
Zearalenona , Animais , Saccharomyces cerevisiae/metabolismo , Transcriptoma , Trichosporon , Xenobióticos , Zearalenona/toxicidadeRESUMO
Catalytic strategies that provide stereoselective access to highly substituted alkenes from abundant monosubstituted substrates are exceedingly sought-after but rare. Here, we show that a N-heterocyclic carbene-NiI catalytic species mediates efficient union of electronically polarized terminal olefins with benzyl chlorides, in the presence of trimethylsilyl triflate and trimethylamine additives, to generate trisubstituted boron- and arene-containing trans alkenes in excellent regio- and stereoselectivities. Control experiments provide evidence for a mechanism involving branched-selective Heck-type benzylation that overrides substrate control, followed by trans-selective 1,3-hydrogen shift. The method represents a significant addition to the toolbox of reactions for the concise synthesis of unsaturated biologically active compounds.
Assuntos
Alcenos , Níquel , Alcenos/química , Catálise , Isomerismo , Estrutura Molecular , Níquel/química , EstereoisomerismoRESUMO
Alkene hydrocarbofunctionalization represents one of the most important classes of chemical transformations, but related branched-selective examples with unactivated olefins are scarce. Here, we report that catalytic amounts of a dimeric Ni(I) complex and an exogenous alkoxide base promote Markovnikov-selective hydroarylation(alkenylation) of unactivated and activated olefins using organo bromides or triflates derived from widely available phenols and ketones. Products bearing aryl- and alkenyl-substituted tertiary and quaternary centers could be isolated in up to 95% yield and >99:1 regioisomeric ratios. Contrary to previous dual-catalytic methods that rely on metal-hydride atom transfer (MHAT) to the olefin prior to carbofunctionalization with a cocatalyst, our mechanistic evidence points toward a nonradical reaction pathway that begins with site-selective carbonickelation across the CâC bond followed by hydride transfer using alkoxide as the hydride source. Utility of the single-catalyst protocol is highlighted through the synthesis of medicinally relevant scaffolds.
RESUMO
A highly efficient iridium-catalyzed cascade annulation of pyrazolones and sulfoxonium ylides to access various pyrazolo[1,2-α]cinnoline derivatives has been achieved. This novel approach expanded the application scope of coupling partners to ylides. The control experiments were performed to give insight into the mechanism of this reaction.
RESUMO
Diazo compounds play an important role as a coupling partner in the synthesis of unique π-conjugated 7-azaindole derivatives via rhodium(iii)-catalyzed double C-H activation/cyclization.
RESUMO
An efficient rhodium-catalyzed dehydrogenative Heck-type reaction between N-aryl-substituted 7-azaindoles and various alkenes through a H2 -releasing process without the need of any oxidizing agent was developed. The novel methodology broadens the scope of metal-catalyzed hydrogen-releasing reactions to include rhodium catalysis.
RESUMO
Rhodium(iii)-catalyzed N-directed ortho C-H activation and subsequent roll-over C-H activation represents an important strategy to synthesize fused polycyclic compounds. Herein, the novel methodology broadens the scope of the coupling partner to alkenes, which working smoothly with 7-azaindoles has been proven to be an efficient and atom-economical strategy to access complex π-conjugated 7-azaindole derivatives.
RESUMO
A novel one-pot synthesis of π-conjugated polycyclic compounds, which could undergo further facile transformation to form complex polycyclic heteroarene compounds, has been realized between 7-azaindoles and α,ß-unsaturated ketones. This distinctive cascade process proceeds via a rhodium(iii)-catalyzed alkylation/copper-catalyzed radical annulation-aromatization pathway.
RESUMO
Decidual macrophages are the second-largest immune cell group at the maternal-foetal interface. They participate in apoptotic cell removal, and protect the foetus from microorganisms or pathogens. Dysfunction of decidual macrophages gives rise to pregnancy complications such as preeclampsia and recurrent spontaneous miscarriage (RSM). However, the mechanisms by which decidual macrophages are involved in the occurrence of adverse pregnancy outcomes have not been elucidated. Here we integrated DNA methylation and gene expression data from decidua macrophages to identify potential risk factors related to RSM. GPR133 was significantly hypomethylated and upregulated in decidual macrophages from RSM patients. Further demethylation analysis demonstrated that GPR133 expression in decidual macrophages was significantly increased by 5-Aza-dC treatment. In addition, the influence of GPR133 on the phagocytic ability of macrophages was explored. Phagocytosis was impaired in the decidual macrophages of RSM patients with increased GPR133 expression. Increased GPR133 expression induced by demethylation treatment in the decidual macrophages of healthy control patients led to a significant decrease in phagocytic function. Importantly, knockdown of GPR133 resulted in a significant improvement in the phagocytic function of THP-1 macrophages. In conclusion, the existing studies have shown the influence of GPR133 on the phagocytic function of decidual macrophages and pregnancy outcomes, providing new data and ideas for future research on the role of decidual macrophages in RSM.
Assuntos
Aborto Espontâneo , Decídua , Feminino , Humanos , Gravidez , Aborto Espontâneo/genética , Decídua/metabolismo , Metilação de DNA , Macrófagos , Fagocitose , Regulação para CimaRESUMO
Maintenance therapy in adult T-cell acute lymphoblastic leukemia (T-ALL) is the longest phase but with limited option. The classic drugs used in the maintenance phase such as 6-mercaptopurine, methotrexate, corticosteroid and vincristine have potentially serious toxicities. Optimizing therapy in the modern age, chemo-free maintenance therapy regimens for patients with T-ALL may dramatically improve the maintenance therapeutic landscape. We report here the combination of Anti-programmed cell death protein 1 antibody and histone deacetylase inhibitor as chemo-free maintenance treatment in a T-ALL patient with literature review, thus providing a unique perspective in addition to valuable information which may inform novel therapeutic approaches.
RESUMO
AMPK plays significant roles in the modulation of metabolic reprogramming and viral infection. However, the detailed mechanism by which AMPK affects viral infection is unclear. The present study aims to determine how AMPK influences white spot syndrome virus (WSSV) infection in shrimp (Marsupenaeus japonicus). Here, we find that AMPK expression and phosphorylation are significantly upregulated in WSSV-infected shrimp. WSSV replication decreases remarkably after knockdown of Ampkα and the shrimp survival rate of AMPK-inhibitor injection shrimp increases significantly, suggesting that AMPK is beneficial for WSSV proliferation. Mechanistically, WSSV infection increases intracellular Ca2+ level, and activates CaMKK, which result in AMPK phosphorylation and partial nuclear translocation. AMPK directly activates mTORC2-AKT signaling pathway to phosphorylate key enzymes of glycolysis in the cytosol and promotes expression of Hif1α to mediate transcription of key glycolytic enzyme genes, both of which lead to increased glycolysis to provide energy for WSSV proliferation. Our findings reveal a novel mechanism by which WSSV exploits the host CaMKK-AMPK-mTORC2 pathway for its proliferation, and suggest that AMPK might be a target for WSSV control in shrimp aquaculture.
Assuntos
Proteínas Quinases Ativadas por AMP , Glicólise , Alvo Mecanístico do Complexo 2 de Rapamicina , Penaeidae , Replicação Viral , Vírus da Síndrome da Mancha Branca 1 , Aerobiose , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Penaeidae/genética , Penaeidae/metabolismo , Fosforilação , Transdução de Sinais , Vírus da Síndrome da Mancha Branca 1/fisiologia , Técnicas de Silenciamento de GenesRESUMO
Prostate cancer (PC) is one of the common malignant tumors of the male genitourinary system. Here, we constructed PTX@ZIF-8, which is a metal-organic-framework-encapsulated drug delivery nanoparticle with paclitaxel (PTX) as a model drug, and further modified the synthesized peptide dimer (Di-PEG2000-COOH) onto the surface of PTX@ZIF-8 to prepare a nanotargeted drug delivery system (Di-PEG@PTX@ZIF-8) for the treatment of prostate cancer. This study investigated the morphology, particle size distribution, zeta potential, drug loading, encapsulation rate, stability, in vitro release behavior, and cytotoxicity of this targeted drug delivery system, and explored the uptake of Di-PEG@PTX@ZIF-8 by human prostate cancer Lncap cells at the in vitro cellular level, as well as the proliferation inhibition and promotion of apoptosis of Lncap cells by the composite nanoparticles. The results suggest that Di-PEG@PTX@ZIF-8, as a zeolitic imidazolate frameworks-8-loaded paclitaxel nanoparticle, has promising potential for the treatment of prostate cancer, which may provide a novel strategy for the delivery system targeting prostate cancer.
RESUMO
In the absence of directing auxiliaries, the catalytic addition of carbogenic groups to unactivated alkenes with control of regioselectivity remains an ongoing challenge in organic chemistry. Here we describe a directing-group-free, nickel-catalysed strategy that couples a broad array of unactivated and activated olefins with aryl-substituted triflates and organometallic nucleophiles to afford diarylation adducts in either regioisomeric form, in up to 93% yield and >98% site selectivity. By switching the reagents involved, the present strategy may be extended to other classes of dicarbofunctionalization reactions. Mechanistic and computational investigations offer insights into the origin of the observed regiochemical outcome and the utility of the method is highlighted through the concise syntheses of biologically active molecules. The catalyst control principles reported are expected to advance efforts towards the development of general site-selective alkene functionalizations, removing the requirement for neighbouring activating groups.
Assuntos
Alcenos/química , Catálise , Indicadores e Reagentes/química , Níquel/químicaRESUMO
Trained immunity is driven by metabolism and epigenetics in innate immune cells in mammals. The phenomenon of trained immunity has been identified in invertebrates, including shrimp, but the underlying mechanisms remain unclear. To elucidate mechanisms of trained immunity in shrimp, the metabolomic changes in hemolymph of Marsupenaeus japonicus trained by the UV-inactivated white spot syndrome virus (UV-WSSV) were analyzed using tandem gas chromatography-mass/mass spectrometry. The metabolomic profiles of shrimp trained with UV-WSSV followed WSSV infection showed significant differences comparison with the control groups, PBS injection followed WSSV infection. 16 differential metabolites in total of 154 metabolites were identified, including D-fructose-6-phosphate, D-glucose-6-phosphate, and D-fructose-6-phosphate, and metabolic pathways, glycolysis, pentose phosphate pathway, and AMPK signaling pathway were enriched in the UV-WSSV trained groups. Further study found that histone monomethylation and trimethylation at H3K4 (H3K4me1 and H3K4me3) were involved in the trained immunity. Our data suggest that the UV-WSSV induced trained immunity leads to metabolism reprogramming in the shrimp and provide insights for WSSV control in shrimp aquaculture.
Assuntos
Penaeidae , Vírus da Síndrome da Mancha Branca 1 , Animais , Proteínas de Artrópodes , Imunidade Inata , Mamíferos/metabolismo , Raios UltravioletaRESUMO
Over the past decade, Apiotrichum mycotoxinivorans has been recognized globally as a source of opportunistic infections. It is a yeast-like fungus, and its association as an uncommon pulmonary pathogen with cystic fibrosis patients has been previously reported. Immunocompromised patients are at the highest risk of A. mycotoxinivorans infections. Therefore, to investigate the genetic basis for the pathogenicity of A. mycotoxinivorans, we performed whole-genome sequencing and comparative genomic analysis of A. mycotoxinivorans GMU1709 that was isolated from sputum specimens of a pneumonia patient receiving cardiac repair surgery. The assembly of Oxford Nanopore reads from the GMU1709 strain and its subsequent correction using Illumina paired-end reads yielded a high-quality complete genome with a genome size of 30.5 Mb in length, which comprised six chromosomes and one mitochondrion. Subsequently, 8,066 protein-coding genes were predicted based on multiple pieces of evidence, including transcriptomes. Phylogenomic analysis indicated that A. mycotoxinivorans exhibited the closest evolutionary affinity to A. veenhuisii, and both the A. mycotoxinivorans strains and the formerly Trichosporon cutaneum ACCC 20271 strain occupied the same phylogenetic position. Further comparative analysis supported that the ACCC 20271 strain belonged to A. mycotoxinivorans. Comparisons of three A. mycotoxinivorans strains indicated that the differences between clinical and non-clinical strains in pathogenicity and drug resistance may be little or none. Based on the comparisons with strains of other species in the Trichosporonaceae family, we identified potential key genetic factors associated with A. mycotoxinivorans infection or pathogenicity. In addition, we also deduced that A. mycotoxinivorans had great potential to inactivate some antibiotics (e.g., tetracycline), which may affect the efficacy of these drugs in co-infection. In general, our analyses provide a better understanding of the classification and phylogeny of the Trichosporonaceae family, uncover the underlying genetic basis of A. mycotoxinivorans infections and associated drug resistance, and provide clues into potential targets for further research and the therapeutic intervention of infections.
Assuntos
Trichosporon , Genoma Bacteriano , Humanos , Filogenia , Análise de Sequência de DNA , Sequenciamento Completo do GenomaRESUMO
Pseudomonas aeruginosa is an opportunistic pathogen, which usually presents multiple antibiotic resistance. Host-directed therapy involves modulating the host defense system and the interplay between innate and adaptive immunity is a new strategy for designing anti-infection drugs. Memantine (MEM), a drug used to treat Alzheimer's disease, has a good inhibitory effect on neonatal mice with Escherichia coli-associated bacteremia and meningitis; however, the inhibitory effect and mechanisms of MEM against P. aeruginosa infection remain unclear. Here, we investigated whether MEM could inhibit P. aeruginosa infection and explored the potential mechanisms. MEM significantly promoted the bactericidal effect of neutrophils against P. aeruginosa and its drug-resistant strain. The combination index of MEM and amikacin (AMK) was <1. In vivo experiments showed that the bacteremia and inflammation severities in the MEM-treated group were less than those in the untreated group, and the bacterial load in the organs was significantly less than that in the control group. Combining MEM with the reactive oxygen species (ROS) inhibitor, N-acetyl-l-cysteine, weakened the anti-infective effect of MEM. MEM increased the expression of NADPH p67phox and promoted neutrophilic ROS production. Deleting the p67phox gene significantly weakened the effects of MEM on ROS generation and improving bactericidal effect of neutrophils. In conclusion, MEM promoted the bactericidal effect of neutrophils against P. aeruginosa and its drug-resistant strain, and had a synergistic antibacterial effect when combined with AMK. MEM may exert its anti-infective effects by promoting neutrophilic bactericidal activity via increasing the expression level of p67phox and further stimulating ROS generation.
Assuntos
Amicacina/farmacologia , Antibacterianos/farmacologia , Memantina/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Acetilcisteína/farmacologia , Animais , Farmacorresistência Bacteriana , Neutrófilos/efeitos dos fármacos , Fosfoproteínas/efeitos dos fármacos , Infecções por Pseudomonas/prevenção & controle , Ratos , Ratos Sprague-DawleyRESUMO
Despite tremendous efforts aimed at devising methods for stereoselective alkene synthesis, critical challenges are yet to be addressed. Direct access to a diverse range of 1aryl(boryl)-1-methyl-functionalized tri- and tetrasubstituted trans alkenes, entities that are prevalent in many important molecules of interest, through a catalytic manifold from readily available α-olefin substrates remains elusive. Here, we demonstrate that catalytic amounts of a nonprecious N-heterocyclic carbene-Ni(I) complex in conjunction with a sterically bulky base promote site- and trans-selective union of monosubstituted olefins with a wide array of electrophilic reagents to deliver tri- and tetrasubstituted alkenes in up to 92% yield and >98% regio- and stereoselectivity. The protocol is amenable to the preparation of carbon- and heteroatom-substituted C=C bonds, providing distinct advantages over existing transformations. Utility is highlighted through concise stereoselective synthesis of biologically active compounds.