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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause acute respiratory disease and multiorgan failure. Finding human host factors that are essential for SARS-CoV-2 infection could facilitate the formulation of treatment strategies. Using a human kidney cell line-HK-2-that is highly susceptible to SARS-CoV-2, we performed a genome-wide RNAi screen and identified virus dependency factors (VDFs), which play regulatory roles in biological pathways linked to clinical manifestations of SARS-CoV-2 infection. We found a role for a secretory form of SARS-CoV-2 receptor, soluble angiotensin converting enzyme 2 (sACE2), in SARS-CoV-2 infection. Further investigation revealed that SARS-CoV-2 exploits receptor-mediated endocytosis through interaction between its spike with sACE2 or sACE2-vasopressin via AT1 or AVPR1B, respectively. Our identification of VDFs and the regulatory effect of sACE2 on SARS-CoV-2 infection shed insight into pathogenesis and cell entry mechanisms of SARS-CoV-2 as well as potential treatment strategies for COVID-19.
Assuntos
Enzima de Conversão de Angiotensina 2/imunologia , Interações entre Hospedeiro e Microrganismos/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vasopressinas/imunologia , Internalização do Vírus , COVID-19/imunologia , COVID-19/virologia , Linhagem Celular , Humanos , Ligação ProteicaRESUMO
Highly pathogenic coronaviruses, including severe acute respiratory syndrome coronavirus 2 (refs. 1,2) (SARS-CoV-2), Middle East respiratory syndrome coronavirus3 (MERS-CoV) and SARS-CoV-1 (ref. 4), vary in their transmissibility and pathogenicity. However, infection by all three viruses results in substantial apoptosis in cell culture5-7 and in patient tissues8-10, suggesting a potential link between apoptosis and pathogenesis of coronaviruses. Here we show that caspase-6, a cysteine-aspartic protease of the apoptosis cascade, serves as an important host factor for efficient coronavirus replication. We demonstrate that caspase-6 cleaves coronavirus nucleocapsid proteins, generating fragments that serve as interferon antagonists, thus facilitating virus replication. Inhibition of caspase-6 substantially attenuates lung pathology and body weight loss in golden Syrian hamsters infected with SARS-CoV-2 and improves the survival of mice expressing human DPP4 that are infected with mouse-adapted MERS-CoV. Our study reveals how coronaviruses exploit a component of the host apoptosis cascade to facilitate virus replication.
Assuntos
Ácido Aspártico , Caspase 6 , Infecções por Coronavirus , Coronavirus , Cisteína , Interações Hospedeiro-Patógeno , Replicação Viral , Animais , Apoptose , Ácido Aspártico/metabolismo , Caspase 6/metabolismo , Coronavirus/crescimento & desenvolvimento , Coronavirus/patogenicidade , Infecções por Coronavirus/enzimologia , Infecções por Coronavirus/virologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Cricetinae , Cisteína/metabolismo , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidase 4/metabolismo , Humanos , Interferons/antagonistas & inibidores , Interferons/imunologia , Pulmão/patologia , Mesocricetus , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , SARS-CoV-2 , Taxa de Sobrevida , Redução de PesoRESUMO
The Omicron (B.1.1.529) variant of SARS-CoV-2 emerged in November 2021 and is rapidly spreading among the human population1. Although recent reports reveal that the Omicron variant robustly escapes vaccine-associated and therapeutic neutralization antibodies2-10, the pathogenicity of the virus remains unknown. Here we show that the replication of Omicron is substantially attenuated in human Calu3 and Caco2 cells. Further mechanistic investigations reveal that Omicron is inefficient in its use of transmembrane serine protease 2 (TMPRSS2) compared with wild-type SARS-CoV-2 (HKU-001a) and previous variants, which may explain its reduced replication in Calu3 and Caco2 cells. The replication of Omicron is markedly attenuated in both the upper and lower respiratory tracts of infected K18-hACE2 mice compared with that of the wild-type strain and Delta (B.1.617.2) variant, resulting in its substantially ameliorated lung pathology. Compared with wild-type SARS-CoV-2 and the Alpha (B.1.1.7), Beta (1.351) and Delta variants, infection by Omicron causes the lowest reduction in body weight and the lowest mortality rate. Overall, our study demonstrates that the replication and pathogenicity of the Omicron variant of SARS-CoV-2 in mice is attenuated compared with the wild-type strain and other variants.
Assuntos
COVID-19/patologia , COVID-19/virologia , SARS-CoV-2/patogenicidade , Replicação Viral , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , COVID-19/imunologia , Células CACO-2 , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Serina Endopeptidases/metabolismo , VirulênciaRESUMO
The high transmissibility of SARS-CoV-2 Omicron subvariants was generally ascribed to immune escape. It remained unclear whether the emerging variants have gradually acquired replicative fitness in human respiratory epithelial cells. We sought to evaluate the replicative fitness of BA.5 and earlier variants in physiologically active respiratory organoids. BA.5 exhibited a dramatically increased replicative capacity and infectivity than B.1.1.529 and an ancestral strain wildtype (WT) in human nasal and airway organoids. BA.5 spike pseudovirus showed a significantly higher entry efficiency than that carrying WT or B.1.1.529 spike. Notably, we observed prominent syncytium formation in BA.5-infected nasal and airway organoids, albeit elusive in WT- and B.1.1.529-infected organoids. BA.5 spike-triggered syncytium formation was verified by lentiviral overexpression of spike in nasal organoids. Moreover, BA.5 replicated modestly in alveolar organoids, with a significantly lower titer than B.1.1.529 and WT. Collectively, the higher entry efficiency and fusogenic activity of BA.5 spike potentiated viral spread through syncytium formation in the human airway epithelium, leading to enhanced replicative fitness and immune evasion, whereas the attenuated replicative capacity of BA.5 in the alveolar organoids may account for its benign clinical manifestation.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/genética , Nariz , Organoides , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Neutralizantes , Anticorpos AntiviraisRESUMO
Protein S-acylation is a reversible post-translational modification (PTM). It is present on diverse proteins and has important roles in regulating protein function. Aminolysis with hydroxylamine is widely used in the global identification of the PTM. However, the identification is indirect. Distinct criteria have been used for identification, and the false discovery rate has not been addressed. Here, we report a site-specific method for S-acylation identification based on tagging of S-acylation sites with iodoTMT0. Efforts to improve the performance of the method and confidence of identification are discussed, highlighting the importance of reducing contaminant peptides and keeping the recovery rate consistent between aliquots with or without hydroxylamine treatment. With very stringent criteria, presumptive S-acylation sites of 269, 684, 695, and 780 were identified from HK2 cells, HK11 cells, mouse brain, and mouse liver samples, respectively. Among them, the newly identified protein S-acylation sites are equivalent to 34% of human and 24% of mouse S-acylation sites reported previously. In addition, false-positive rates for S-acylation identification and S-acylation abundances were estimated. Significant differences in S-acylation abundance were found from different samples (from 0.08% in HK2 cells to 0.76% in mouse brain), and the false-positive rates were significantly higher for samples with a low abundance of S-acylation.
Assuntos
Processamento de Proteína Pós-Traducional , Proteínas , Animais , Camundongos , Humanos , Acilação , Lipoilação , Hidroxilamina , HidroxilaminasRESUMO
T lymphocytes are the major components of adaptive immunity in Behçet's syndrome (BS) pathology. However, the precise mechanism of T-cell-induced inflammatory condition remains to be determined. We applied bulk sequencing of the T-cell receptor (TCR) ß chain in peripheral blood samples from 45 patients with BS and 10 healthy donors as controls. TCR repertoires in BS patients displayed more clonality and less diversity than in healthy donors. Male patients exhibited lower diversity metrics of TCR and had a larger proportion in the top 10 clones than females (p = 0.016). There were no TCR clonality differences in other clinical features, such as age, disease duration, organ involvement, disease severity, and activity. By "Grouping of Lymphocyte Interactions by Paratope Hotspots" (GLIPH2) for antigen prediction, we found distinct 2477 clusters of TCR-ß sequences that potentially recognize similar antigens shared between BS patients. We observed clonal T-cell expansion in BS patients. Sexual differences in TCR clonal expansion and public TCR groups deserve further study to reveal the underline T-cell-mediated immunity in BS.
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Síndrome de Behçet , Linfócitos T , Feminino , Humanos , Masculino , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Imunidade Celular , Imunidade Adaptativa , Receptores de Antígenos de Linfócitos T/genéticaRESUMO
To elucidate the impact of CYP3A4 activity inhibition and genetic polymorphism on the metabolism of crizotinib. Enzymatic incubation systems for crizotinib were established, and Sprague-Dawley rats were utilized for in vivo experiments. Analytes were quantified using LC-MS/MS. Upon screening 122 drugs and natural compounds, proanthocyanidins emerged as inhibitor of crizotinib metabolism, exhibiting a relative inhibition rate of 93.7%. The IC50 values were 24.53 ± 0.32 µM in rat liver microsomes and 18.24 ± 0.12 µM in human liver microsomes. In vivo studies revealed that proanthocyanidins markedly affected the pharmacokinetic parameters of crizotinib. Co-administration led to a significant reduction in the AUC(0-t), Cmax of PF-06260182 (the primary metabolite of crizotinib), and the urinary metabolic ratio. This interaction is attributed to the mixed-type inhibition of liver microsome activity by proanthocyanidins. CYP3A4, being the principal metabolic enzyme for crizotinib, has its genetic polymorphisms significantly influencing crizotinib's pharmacokinetics. Kinetic data showed that the relative metabolic rates of crizotinib across 26 CYP3A4 variants ranged from 13.14% (CYP3A4.12, 13) to 188.57% (CYP3A4.33) when compared to the wild-type CYP3A4.1. Additionally, the inhibitory effects of proanthocyanidins varied between CYP3A4.12 and CYP3A4.33, when compared to the wild type. Our findings indicate that proanthocyanidins coadministration and CYP3A4 genetic polymorphism can significantly influence crizotinib metabolism.
Assuntos
Crizotinibe , Citocromo P-450 CYP3A , Interações Medicamentosas , Microssomos Hepáticos , Polimorfismo Genético , Ratos Sprague-Dawley , Crizotinibe/farmacocinética , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Animais , Humanos , Masculino , Microssomos Hepáticos/metabolismo , Microssomos Hepáticos/enzimologia , Microssomos Hepáticos/efeitos dos fármacos , Ratos , Piridinas/farmacocinética , Pirazóis/farmacocinética , Pirazóis/farmacologiaRESUMO
The recovery of an unknown density matrix of large size requires huge computational resources. State-of-the-art performance has recently been achieved with the factored gradient descent (FGD) algorithm and its variants since they are able to mitigate the dimensionality barrier by utilizing some of the underlying structures of the density matrix. Despite the theoretical guarantee of a linear convergence rate, convergence in practical scenarios is still slow because the contracting factor of the FGD algorithms depends on the condition number κ of the ground truth state. Consequently, the total number of iterations needed to achieve the estimation error ϵ can be as large as O(sqrt[κ]ln(1/ϵ)). In this Letter, we derive a quantum state tomography scheme that improves the dependence on κ to the logarithmic scale. Thus, our algorithm can achieve the approximation error ϵ in O(ln(1/κϵ)) steps. The improvement comes from the application of nonconvex Riemannian gradient descent (RGD). The contracting factor in our approach is thus a universal constant that is independent of the given state. Our theoretical results of extremely fast convergence and nearly optimal error bounds are corroborated by the numerical results.
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BACKGROUND: Surgical therapy is the most optimal treatment for hepatocellular carcinoma (HCC) combined with bile duct tumor thrombus (BDTT) patients. However, whether to perform bile duct resection (BDR) is still controversial. The purpose of this multicenter research is to compare the effect of BDR on the prognosis of extrahepatic BDTT patients. METHODS: We collected the data of 111 HCC patients combined with extrahepatic BDTT who underwent radical hepatectomy from June 1, 2004 to December 31, 2021. Those patients had either received hepatectomy with extrahepatic bile duct resection (BDR group) or hepatectomy without bile duct resection (NBDR group). Inverse probability of treatment weighting (IPTW) was used to reduce the potential bias between two groups and balance the influence of confounding factors in baseline data. Then compare the prognosis between the two groups of patients. Cox regression model was used for univariate and multivariate analysis to further determine the independent risk factors that influence the prognosis of HCC-BDTT patients. RESULTS: There were 38 patients in the BDR group and 73 patients in the NBDR group. Before and after IPTW, there were no statistical significance in OS, RFS and intraoperative median blood loss between the two groups (all P > 0.05). Before IPTW, the median postoperative hospital stay in the NBDR group was shorter (P = 0.046) and the grade of postoperative complications was lower than BDR group (P = 0.014). After IPTW, there was no difference in postoperative hospital stay between the two groups (P > 0.05). The complication grade in the NBDR group was still lower than that in the BDR group (P = 0.046). The univariate analysis showed that TNM stage and portal vein tumor thrombus (PVTT) were significantly correlated with OS (both P < 0.05). Preoperative AFP level, TNM stage and prognostic nutritional index (PNI) were significantly correlated with postoperative RFS (all P < 0.05). Multivariate analysis showed that tumor TNM stage was an independent risk factor for the OS rate (P = 0.014). TNM stage, PNI and AFP were independent predictors of RFS after radical hepatectomy (all P < 0.05). CONCLUSIONS: For HCC-BDTT patients, hepatocellular carcinoma resection combined with choledochotomy to remove the tumor thrombus may benefit more.
Assuntos
Ductos Biliares Extra-Hepáticos , Carcinoma Hepatocelular , Hepatectomia , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/complicações , Masculino , Feminino , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/complicações , Pessoa de Meia-Idade , Prognóstico , Ductos Biliares Extra-Hepáticos/cirurgia , Ductos Biliares Extra-Hepáticos/patologia , Trombose/cirurgia , Trombose/etiologia , Trombose/patologia , Estudos Retrospectivos , Neoplasias dos Ductos Biliares/cirurgia , Neoplasias dos Ductos Biliares/patologia , Neoplasias dos Ductos Biliares/complicações , Neoplasias dos Ductos Biliares/mortalidade , Idoso , AdultoRESUMO
BACKGROUND AND AIMS: The aim of this study was to determine if utilization of artificial intelligence (AI) in the course of endoscopic procedures can significantly diminish both the adenoma miss rate (AMR) and the polyp miss rate (PMR) compared with standard endoscopy. METHODS: We performed an extensive search of various databases, encompassing PubMed, Embase, Cochrane Library, Web of Science, and Scopus, until June 2023. The search terms used were artificial intelligence, machine learning, deep learning, transfer machine learning, computer-assisted diagnosis, convolutional neural networks, gastrointestinal (GI) endoscopy, endoscopic image analysis, polyp, adenoma, and neoplasms. The main study aim was to explore the impact of AI on the AMR, PMR, and sessile serrated lesion miss rate. RESULTS: A total of 7 randomized controlled trials were included in this meta-analysis. Pooled AMR was markedly lower in the AI group versus the non-AI group (pooled relative risk [RR], .46; 95% confidence interval [CI], .36-.59; P < .001). PMR was also reduced in the AI group in contrast with the non-AI control (pooled RR, .43; 95% CI, .27-.69; P < .001). The results showed that AI decreased the miss rate of sessile serrated lesions (pooled RR, .43; 95% CI, .20 to .92; P < .05) and diminutive adenomas (pooled RR, .49; 95% CI, .26-.93) during endoscopy, but no significant effect was observed for advanced adenomas (pooled RR, .48; 95% CI, .17-1.37; P = .17). The average number of polyps (Hedges' g = -.486; 95% CI, -.697 to -.274; P = .000) and adenomas (Hedges' g = -.312; 95% CI, -.551 to -.074; P = .01) detected during the second procedure also favored AI. However, AI implementation did not lead to a prolonged withdrawal time (P > .05). CONCLUSIONS: This meta-analysis suggests that AI technology leads to significant reduction of miss rates for GI adenomas, polyps, and sessile serrated lesions during endoscopic surveillance. These results underscore the potential of AI to improve the accuracy and efficiency of GI endoscopic procedures.
RESUMO
The α-L-arabinofuranosidase enzyme plays a crucial role in the degradation of ginsenosides. In this study, we successfully cloned and expressed a novel α-L-arabinofuranosidase bsafs gene (1503 bp, 501 amino acids, 55 kDa, and pI = 5.4) belonging to glycosyl hydrolase (GH) family 51 from Bacillus subtilis genome in Escherichia coli BL21 cells. The recombinant protein Bsafs was purified using Ni2+ sepharose fastflow affinity chromatography and exhibited a specific activity of 2.91 U/mg. Bsafs effectively hydrolyzed the α-L-arabinofuranoside at C20 site of ginsenoside Rc to produce Rd as the product. The Km values for hydrolysis of pNP-α-L-arabinofuranoside (pNPαAraf) and ginsenoside Rc were determined as 0.74 and 4.59 mmol/L, respectively; while the Vmax values for these substrates were found to be 24 and 164 µmol/min/mg, respectively; furthermore, the Kcat values for these enzymes were calculated as 22.3 and 1.58 S-1 correspondingly.
Assuntos
Ginsenosídeos , Ginsenosídeos/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Clonagem Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Glicosídeo Hidrolases/metabolismo , Especificidade por SubstratoRESUMO
Refined indigenous Saccharomyces cerevisiae can enhance refinement, sophistication, and subtlety of fruit wines by showcasing exceptional regional characteristics. In order to identify exceptional indigenous S. cerevisiae strains from Yunnan olive, this study isolated 60 yeast strains from wild Yunnan olive fermentation mash. The five S. cerevisiae strains were subjected to morphological and molecular biological identification, followed by evaluation of their fermentation performance, ethanol production capacity, ester production capacity, H2S production capacity, killing capacity, and tolerance. Strains LJM-4, LJM-10, and LJM-26 exhibited robust tolerance to 6% ethanol volume fraction, pH 2.8, sucrose concentration of 400 g/L, SO2 concentration of 0.3 g/L, glucose concentration of 400 g/L at both 40 °C and 15 °C. Additionally, strain LJM-10 demonstrated a faster fermentation rate compared to the other strains. Among the tested S. cerevisiae strains evaluated in this study for olive wine fermentation process in Yunnan region; strain LJM-10 displayed superior abilities in terms of ester and ethanol production while exhibiting the lowest H2S production levels. These findings suggest that strain LJM-10 holds great potential as an excellent candidate for optimizing fruit wine S. cerevisiae fermentation processes in Yunnan olive fruit wine.
Assuntos
Olea , Vinho , Saccharomyces cerevisiae/genética , Fermentação , China , Vinho/análise , Etanol/análise , ÉsteresRESUMO
The present study focuses on investigating 60 strains of yeast isolated from the natural fermentation broth of Vitis labruscana Baily × Vitis vinifera L. These strains underwent screening using lysine culture medium and esculin culture medium, resulting in the identification of 27 local non-Saccharomyces yeast strains exhibiting high ß-glucosidase production. Subsequent analysis of their fermentation characteristics led to the selection of four superior strains (Z-6, Z-11, Z-25, and Z-58) with excellent ß-glucosidase production and fermentation performance. Notably, these selected strains displayed a dark coloration on esculin medium and exhibited robust gas production during Duchenne tubules' fermentation test. Furthermore, all four non-Saccharomyces yeast strains demonstrated normal growth under specific conditions including SO2 mass concentration ranging from 0.1 to 0.3 g/L, temperature between 25 and 30 °C, glucose mass concentration ranging from 200 to 400 g/L, and ethanol concentration at approximately 4%. Molecular biology identification confirmed that all selected strains belonged to Pichia kudriavzevii species which holds great potential for wine production.
Assuntos
Vitis , Vinho , Saccharomyces cerevisiae/metabolismo , Fermentação , beta-Glucosidase/metabolismo , Esculina/análise , Leveduras/metabolismo , Vinho/análise , Pichia/metabolismoRESUMO
Yeast, which plays a pivotal role in the brewing, food, and medical industries, exhibits a close relationship with human beings. In this study, we isolated and purified 60 yeast strains from the natural fermentation broth of Sidamo coffee beans to screen for indigenous beneficial yeasts. Among them, 25 strains were obtained through morphological characterization on nutritional agar medium from Wallerstein Laboratory (WL), with molecular biology identifying Saccharomyces cerevisiae strain YBB-47 and the remaining 24 yeast strains identified as Pichia kudriavzevii. We investigated the fermentation performance, alcohol tolerance, SO2 tolerance, pH tolerance, sugar tolerance, temperature tolerance, ester production capacity, ethanol production capacity, H2S production capacity, and other brewing characteristics of YBB-33 and YBB-47. The results demonstrated that both strains could tolerate up to 3% alcohol by volume at a high sucrose mass concentration (400 g/L) under elevated temperature conditions (40 â), while also exhibiting a remarkable ability to withstand an SO2 mass concentration of 300 g/L at pH 3.2. Moreover, S. cerevisiae YBB-47 displayed a rapid gas production rate and strong ethanol productivity. whereas P. kudriavzevii YBB-33 exhibited excellent alcohol tolerance. Furthermore, this systematic classification and characterization of coffee bean yeast strains from the Sidamo region can potentially uncover additional yeasts that offer high-quality resources for industrial-scale coffee bean production.
Assuntos
Etanol , Fermentação , Pichia , Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/isolamento & purificação , Pichia/metabolismo , Pichia/isolamento & purificação , Pichia/genética , Pichia/classificação , Etanol/metabolismo , Concentração de Íons de Hidrogênio , Café/microbiologia , Coffea/microbiologia , Temperatura , Sementes/microbiologia , Sulfeto de Hidrogênio/metabolismoRESUMO
Natural ginsenoside needs to be converted into rare ginsenoside before it can be readily absorbed into the bloodstream for action. In this study, an α-l-arabinofuranosidase (α-l-AFase) gene Bsafs2 was cloned from Bacillus subtilis (B. subtilis). Bsafs2 was ligated to the expression vector pET28a(+), and the expression vector was constructed and transformed into Escherichia coli (E. coli) BL21 heterologous recombinant expression to obtain α-l-AFase. α-l-AFase can hydrolyze at the C20 site of Ginsenoside Rc to obtain rare ginsenoside Rd. Studies on the enzymatic property showed that α-l-AFase had good tolerance to ethanol, glucose, and l-arabinose. The optimum temperature of α-l-AFase was 40 °C and pH = 5.5. Kinetic parameters Km of α-l-AFase for pNPαAraf and Ginsenoside Rc were 1.93 and 8.9 mmol/L, the Vmax were 26 and 154 µmol/min/mg, the Kcat were 24.14 and 1.48 S-1, respectively. This study provides the enzyme source for the biotransformation of Ginsenoside Rc.
Assuntos
Ginsenosídeos , Ginsenosídeos/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Clonagem Molecular , Proteínas Recombinantes/química , Escherichia coli/metabolismo , Glicosídeo Hidrolases/químicaRESUMO
Resistance to temozolomide (TMZ), the frontline chemotherapeutic agent for glioblastoma (GBM), has emerged as a formidable obstacle, underscoring the imperative to identify alternative therapeutic strategies to improve patient outcomes. In this study, we comprehensively evaluated a novel agent, O6-methyl-2'-deoxyguanosine-5'-triphosphate (O6-methyl-dGTP) for its anti-GBM activity both in vitro and in vivo. Notably, O6-methyl-dGTP exhibited pronounced cytotoxicity against GBM cells, including those resistant to TMZ and overexpressing O6-methylguanine-DNA methyltransferase (MGMT). Mechanistic investigations revealed that O6-methyl-dGTP could be incorporated into genomic DNA, disrupting nucleotide pools balance, and inducing replication stress, resulting in S-phase arrest and DNA damage. The compound exerted its anti-tumor properties through the activation of AIF-mediated apoptosis and the parthanatos pathway. In vivo studies using U251 and Ln229 cell xenografts supported the robust tumor-inhibitory capacity of O6-methyl-dGTP. In an orthotopic transplantation model with U87MG cells, O6-methyl-dGTP showcased marginally superior tumor-suppressive activity compared to TMZ. In summary, our research, for the first time, underscores the potential of O6-methyl-dGTP as an effective candidate against GBM, laying a robust scientific groundwork for its potential clinical adoption in GBM treatment regimens.
Assuntos
Glioblastoma , Polifosfatos , Humanos , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Nucleosídeos/farmacologia , Nucleosídeos/uso terapêutico , Caspases , Linhagem Celular Tumoral , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Nucleotídeos , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , O(6)-Metilguanina-DNA Metiltransferase/farmacologia , O(6)-Metilguanina-DNA Metiltransferase/uso terapêutico , Desoxiguanosina/farmacologia , Desoxiguanosina/uso terapêutico , DNA , Resistencia a Medicamentos AntineoplásicosRESUMO
It is necessary to predict the critical transition of lake ecosystems due to their abrupt, non-linear effects on social-economic systems. Given the promising application of paleolimnological archives to tracking the historical changes of lake ecosystems, it is speculated that they can also record the lake's critical transition. We studied Lake Dali-Nor in the arid region of Inner Mongolia because of the profound shrinking the lake experienced between the 1300 s and the 1600 s. We reconstructed the succession of bacterial communities from a 140-cm-long sediment core at 4-cm intervals and detected the critical transition. Our results showed that the historical trajectory of bacterial communities from the 1200 s to the 2010s was divided into two alternative states: state1 from 1200 to 1300 s and state2 from 1400 to 2010s. Furthermore, in the late 1300 s, the appearance of a tipping point and critical slowing down implied the existence of a critical transition. By using a multi-decadal time series from the sedimentary core, with general Lotka-Volterra model simulations, local stability analysis found that bacterial communities were the most unstable as they approached the critical transition, suggesting that the collapse of stability triggers the community shift from an equilibrium state to another state. Furthermore, the most unstable community harbored the strongest antagonistic and mutualistic interactions, which may imply the detrimental role of interaction strength on community stability. Collectively, our study showed that sediment DNA can be used to detect the critical transition of lake ecosystems.
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Bactérias , DNA Bacteriano , Sedimentos Geológicos , Lagos , Lagos/microbiologia , Lagos/química , Sedimentos Geológicos/microbiologia , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , China , DNA Bacteriano/genética , Ecossistema , RNA Ribossômico 16S/genética , MicrobiotaRESUMO
An unprecedented di-seco-indole diterpenoid, peniditerpenoid A (1), and a rare N-oxide-containing indole diterpenoid derivative, peniditerpenoid B (2), together with three known ones (3-5), were obtained from the mangrove-sediment-derived fungus Penicillium sp. SCSIO 41411. Their structures were determined by the analysis of spectroscopic data, quantum chemical calculations, and X-ray diffraction analyses. Peniditerpenoid A (1) inhibited lipopolysaccharide-induced NF-κB with an IC50 value of 11 µM and further effectively prevented RANKL-induced osteoclast differentiation in bone marrow macrophages. In vitro studies demonstrated that 1 exerted significant inhibition of NF-κB activation in the classical pathway by preventing TAK1 activation, IκBα phosphorylation, and p65 translocation. Furthermore, 1 effectively reduced the level of NFATc1 activation, resulting in the attenuation of osteoclast differentiation. Our findings suggest that 1 holds promise as an inhibitor with significant potential for the treatment of diseases related to osteoporosis.
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Diferenciação Celular , Diterpenos , Indóis , NF-kappa B , Osteoclastos , Penicillium , Penicillium/química , Osteoclastos/efeitos dos fármacos , Diterpenos/farmacologia , Diterpenos/química , Diterpenos/isolamento & purificação , Animais , Camundongos , Diferenciação Celular/efeitos dos fármacos , Estrutura Molecular , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Indóis/farmacologia , Indóis/química , Ligante RANK/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacosRESUMO
Four new p-terphenyl derivatives, talaroterphenyls A-D (1-4), together with three biosynthetically related known ones (5-7), were obtained from the mangrove sediment-derived Talaromyces sp. SCSIO 41412. Compounds 1-3 are rare p-terphenyls, which are completely substituted on the central benzene ring by oxygen atoms; this is the first report of their isolation from natural sources. Their structures were elucidated through NMR spectroscopy, HRESIMS, and X-ray diffraction. Genome sequence analysis revealed that 1-7 were biosynthesized from tyrosine and phenylalanine, involving four key biosynthetic genes (ttpB-ttpE). These p-terphenyls (1-7) and 36 marine-derived terphenyl analogues (8-43) were screened for phosphodiesterase 4 (PDE4) inhibitory activities, and 1-5, 14, 17, 23, and 26 showed notable activities with IC50 values of 0.40-16 µM. The binding pattern of p-terphenyl inhibitors 1-3 with PDE4 were explored by molecular docking analysis. Talaroterphenyl A (1), with a low cytotoxicity, showed obvious anti-inflammatory activity in LPS-stimulated RAW264.7 cells. Furthermore, in the TGF-ß1-induced medical research council cell strain-5 (MRC-5) pulmonary fibrosis model, 1 could down-regulate the expression levels of FN1, COL1, and α-SMA significantly at concentrations of 5-20 µM. This study suggests that the oxidized p-terphenyl 1, as a marine-derived PDE4 inhibitor, could be used as a promising antifibrotic agent.