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BACKGROUND: Oritavancin is a new generation of semi-synthetic glycopeptide antibiotics against Gram-positive bacteria, which served as the first and only antibiotic with a single-dose therapeutic regimen to treat ABSSSI. A naturally occurring glycopeptide A82846B is the direct precursor of oritavancin. However, its application has been hampered by low yields and homologous impurities. This study established a multi-step combinatorial strategy to rationally construct a high-quality and high-efficiency biosynthesis system for A82846B and systematically optimize its fermentation process to break through the bottleneck of microbial fermentation production. RESULTS: Firstly, based on the genome sequencing and analysis, we deleted putative competitive pathways and constructed a better A82846B-producing strain with a cleaner metabolic background, increasing A82846B production from 92 to 174 mg/L. Subsequently, the PhiC31 integrase system was introduced based on the CRISPR-Cas12a system. Then, the fermentation level of A82846B was improved to 226 mg/L by over-expressing the pathway-specific regulator StrR via the constructed PhiC31 system. Furthermore, overexpressing glycosyl-synthesis gene evaE enhanced the production to 332 mg/L due to the great conversion of the intermediate to target product. Finally, the scale-up production of A82846B reached 725 mg/L in a 15 L fermenter under fermentation optimization, which is the highest reported yield of A82846B without the generation of homologous impurities. CONCLUSION: Under approaches including blocking competitive pathways, inserting site-specific recombination system, overexpressing regulator, overexpressing glycosyl-synthesis gene and optimizing fermentation process, a multi-step combinatorial strategy for the high-level production of A82846B was developed, constructing a high-producing strain AO-6. The combinatorial strategies employed here can be widely applied to improve the fermentation level of other microbial secondary metabolites, providing a reference for constructing an efficient microbial cell factory for high-value natural products.
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Amycolatopsis , Fermentação , Engenharia Metabólica , Amycolatopsis/metabolismo , Amycolatopsis/genética , Engenharia Metabólica/métodos , Sistemas CRISPR-Cas , Antibacterianos/biossíntese , Vias Biossintéticas , Glicopeptídeos/biossínteseRESUMO
AIMS: We evaluated whether the randomness of mutation breeding can be regulated through a double-reporter system. We hope that by establishing a new precursor feeding strategy, the production capacity of industrial microorganisms after pilot scale-up can be further improved. METHODS AND RESULTS: In this study, the industrial strain Streptomyces roseosporus L2796 was used as the starter strain for daptomycin production, and a double-reporter system with the kanamycin resistance gene Neo and the chromogenic gene gusA was constructed to screen for high-yield strain L2201 through atmospheric and room temperature plasma (ARTP). Furthermore, the composition of the culture medium and the parameters of precursor replenishment were optimized, resulting in a significant enhancement of the daptomycin yield of the mutant strain L2201(752.67 mg/l). CONCLUSIONS: This study successfully screened a high-yield strain of daptomycin through a double-reporter system combined with ARTP mutation. The expression level of two reporter genes can evaluate the strength of dptEp promoter, which can stimulate the expression level of dptE in the biosynthesis of daptomycin, thus producing more daptomycin. The developed multi-stage feeding rate strategy provides a novel way to increase daptomycin in industrial fermentation.
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Daptomicina , Streptomyces , Fermentação , Mutagênese , Mutação , Streptomyces/genética , Streptomyces/metabolismoRESUMO
Objective To investigate the effects of Weidiao-3(WD-3)Mixture on the clinical efficacy of immunotherapy for advanced gastric cancer and the intestinal flora.Methods Fifty-one patients with advanced gastric cancer treated in Wuxi Traditional Chinese Medicine Hospital from January 2020 to December 2021 were randomized into a WD-3 group(immunotherapy + WD-3 Mixture,one dose per day)(n=25)and a gastric cancer(GC) group(only immunotherapy)(n=26)according to the admission time.Ten healthy volunteers were included as the healthy control group.The Karnofsky score and the Quality of Life Questionnare-Core score were evaluated before and after treatment,and the clinical efficacy was compared after treatment.After treatment,the stool samples were collected for 16SrRNA gene high-throughput sequencing and targeted metabolomics.The α and ß diversity and structure of the intestinal flora and the content of short-chain fatty acids were compared between groups.Results The quality of life in both groups improved after treatment and was better in the WD-3 group than in the GC group(P=0.035).The dry mouth(P=0.038)and altered taste(P=0.008)were mitigated in the WD-3 group after treatment,and the reflux(P=0.001)and dry mouth(P=0.022)were mitigated in the GC group after treatment.After treatment,the WD-3 group outperformed the GC group in terms of dysphagia(P=0.047)and dry mouth(P=0.045).The WD-3 group was superior to the GC group in terms of objective remission rate and disease control rate,with prolonged median progression-free survival and median overall survival(P=0.039,P=0.043).The α and ß diversity indexes of the intestinal flora showed no significant differences between WD-3 and GC groups(all P>0.05).At the phylum level,WD-3 and GC groups had lower relative abundance of Firmicutes(P=0.038,P=0.042)and higher relative abundance of Proteobacteria(P=0.016,P=0.015)than the healthy control group.The relative abundance of Actinomycetes in the GC group was lower than that in the healthy control group(P=0.035)and the WD-3 group(P=0.046).At the genus level,the GC group had lower relative abundance of Bifidobacteria and Coprococcus than the healthy control group and the WD-3 group(all P<0.001).LEfSe revealed the differences in the relative abundance of 6 intestinal bacterial taxa between the WD-3 group and the GC group.At the genus level,Saccharopolyspora had higher relative abundance in the WD-3 group than in the healthy control group and only existed in the WD-3 group.The content of isobutyric acid and isovaleric acid in the WD-3 group was higher than that in the healthy control group(P=0.037,P=0.004).Conclusion WD-3 Mixture may increase the relative abundance of Bifidobacteria and Coprococcus and the content of isobutyric acid and isovaleric acid to alter the intestinal microecology,thereby improving the efficacy of immunotherapy for gastric cancer.
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Microbioma Gastrointestinal , Neoplasias Gástricas , Humanos , Isobutiratos , Qualidade de Vida , Neoplasias Gástricas/terapia , Imunoterapia , Resultado do TratamentoRESUMO
Daptomycin is a new lipopeptide antibiotic for treatment of severe infection caused by multi-drug-resistant bacteria, but its production cost remains high currently. Thus, it is very important to improve the fermentation ability of the daptomycin producer Streptomyces roseosporus. Here, we found that the deletion of proteasome in S. roseosporus would result in the loss of ability to produce daptomycin. Therefore, transcriptome and 4D label-free proteome analyses of the proteasome mutant (Δprc) and wild type were carried out, showing 457 differential genes. Further, five genes were screened by integrated crotonylation omics analysis. Among them, two genes (orf04750/orf05959) could significantly promote the daptomycin synthesis by overexpression, and the fermentation yield in shake flask increased by 54% and 76.7%, respectively. By enhancing the crotonylation modification via lysine site mutation (K-Q), the daptomycin production in shake flask was finally increased by 98.8% and 206.3%, respectively. This result proved that the crotonylation modification of appropriate proteins could effectively modulate daptomycin biosynthesis. In summary, we established a novel strategy of gene screen for antibiotic biosynthesis process, which is more convenient than the previous screening method based on pathway-specific regulators. KEY POINTS: ⢠Δprc strain has lost the ability of daptomycin production ⢠Five genes were screened by multi-omics analysis ⢠Two genes (orf04750/orf05959) could promote the daptomycin synthesis by overexpression.
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Daptomicina , Streptomyces , Antibacterianos/farmacologia , Complexo de Endopeptidases do Proteassoma , Proteoma/metabolismo , Streptomyces/metabolismoRESUMO
By incorporating the CsPbBr3 quantum dots (QDs) into a glass host, we report for the first time, to our knowledge, the measurement of non-resonant optical nonlinearity and multiphoton upconversion (UC) processes for this QD-in-glass composite. We observe up to four-photon stable UC photoluminescence under excitation by infrared femtosecond pulses, low optical limiting thresholds, and high nonlinear optical absorption coefficients close to those of colloid processed metal halide perovskite (MHP) QDs. Combined with high robustness against air and moisture, the monolithic inorganic glass with incorporated MHP QDs could be a better platform for exploiting strong light-matter interaction for MHPs.
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Avian Tembusu virus (TMUV) is a newly emerging avian pathogenic flavivirus in China and Southeast Asia with features of rapid spread, an expanding host range, and cross-species transmission. The mechanisms of its infection and pathogenesis remain largely unclear. Here, we investigated the tropism of this arbovirus in peripheral blood mononuclear cells of specific-pathogen-free (SPF) ducks and SPF chickens and identified monocytes/macrophages as the key targets of TMUV infection. In vivo studies in SPF ducks and SPF chickens with monocyte/macrophage clearance demonstrated that the infection of monocytes/macrophages was crucial for viral replication, transmission, and pathogenesis. Further genome-wide transcriptome analyses of TMUV-infected chicken macrophages revealed that host antiviral innate immune barriers were the major targets of TMUV in macrophages. Despite the activation of major pattern recognition receptor signaling, the inductions of alpha interferon (IFN-α) and IFN-ß were blocked by TMUV infection on transcription and translation levels, respectively. Meanwhile, TMUV inhibited host redox responses by repressing the transcription of genes encoding NADPH oxidase subunits and promoting Nrf2-mediated antioxidant responses. The recovery of either of the above-mentioned innate immune barriers was sufficient to suppress TMUV infection. Collectively, we identify an essential step of TMUV infection and reveal extensive subversion of host antiviral innate immune responses.IMPORTANCE Mosquito-borne flaviviruses include a group of pathogenic viruses that cause serious diseases in humans and animals, including dengue, West Nile, and Japanese encephalitis viruses. These flaviviruses are zoonotic and use animals, including birds, as amplifying and reservoir hosts. Avian Tembusu virus (TMUV) is an emerging mosquito-borne flavivirus that is pathogenic for many avian species and can infect cells derived from mammals and humans in vitro Although not currently pathogenic for primates, the infection of duck industry workers and the potential risk of TMUV infection in immunocompromised individuals have been highlighted. Thus, the prevention of TMUV in flocks is important for both avian and mammalian health. Our study reveals the escape of TMUV from the first line of the host defense system in the arthropod-borne transmission route of arboviruses, possibly helping to extend our understanding of flavivirus infection in birds and refine the design of anti-TMUV therapeutics.
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Infecções por Flavivirus/imunologia , Flavivirus/imunologia , Animais , Galinhas/virologia , China , Patos/virologia , Feminino , Flavivirus/metabolismo , Infecções por Flavivirus/metabolismo , Especificidade de Hospedeiro/genética , Interações Hospedeiro-Patógeno/genética , Imunidade Inata/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Doenças das Aves Domésticas/virologia , Replicação Viral/efeitos dos fármacosRESUMO
Lack of deep understanding of nanoparticle (NP) actions at oil/water interface set an obstacle to practical applications of Pickering emulsions. Fluorescence labels fabricated by incorporation of carbon dots (CDs) into poly(N-isopropylacrylamide) (PNIPAM) matrix can not only mark the action of PNIPAM-based NPs in the interface but also reflect the colloidal morphologies of PNIPAM. In this work, we employed coaxial electrospraying for fabricating core-shell nanospheres of cellulose acetate encapsulated by PNIPAM, and facile incorporation of CDs in PNIPAM shells was achieved simultaneously. The coaxial electrosprayed NPs (CENPs) with temperature-dependent wettability can stabilize heptane and toluene in water at 25 °C, respectively, and reversible emulsion break can be triggered by temperature adjustment around the low critical solution temperature (LCST). Remarkably, CENP/CD composites exhibited a fluorescence "on-off" behavior because of the volume phase transition of the PNIPAM shell. CENP/CD composites in Pickering emulsions clearly elucidated the motions of CENPs in response to temperature changes. At temperatures below the LCST, the CENP concentration played an important role in surface coverage of oil droplets. Specifically, the CENP concentration above the minimum concentration for complete emulsification of oil phase led to high surface coverage and two-domain adsorption of CENPs at the interface including primary monolayer anchoring of CENPs on droplets surrounded by interconnected CENP networks, which contributed to the superior stability of the emulsions. Moreover, CENP/CD composites can be recycled with well-preserved core-shell structure and stable fluorescent properties, which offers their great potential applications in sensors and imaging.
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To observe the effect of Xiaoqinglong decoction combined with noninvasive ventilation on procalcitonin (PCT), blood gas analysis and respiratory functions in acute exacerbation of chronic obstructive pulmonary disease in the elderly (AECOPD), and investigate its correlation and clinical significance. Eighty-four elderly AECOPD patients with respiratory failure in our hospital from January 2015 to October 2017, were randomly divided into control group and observation group, 42 cases in each group. The control group received western medicine combined with noninvasive ventilator therapy, and the patients in observation group additionally received Xiaoqinglong decoction on the basis of the treatment in control group. Both groups were treated for 2 weeks. The clinical effects of two groups were observed and their PCT, blood gas analysis outcomes [arterial oxygen partial pressure (PaO2), arterial partial pressure of carbon dioxide (PaCO2), respiratory function, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC], TCM syndrome score and other indexes and adverse reactions were compared before and after treatment. The total efficiency was 95.24% (40/42) in observation group, higher than 76.19% (32/42) in control group, with statistically significant difference (P<0.05). There were no statistically significant differences in PCT, PaO2, PaCO2, FVC, FEV1/FVC, FEV1, and TCM syndrome scores between two groups before treatment. But after treatment, PCT and PaCO2 levels in the observation group were lower and PaO2, FVC, FEV1/FVC, FEV1 levels was higher than those in the control group (P<0.05); TCM syndrome scores were lower than those in the control group (P<0.05); both groups had no obvious adverse reactions. The results showed that Xiaoqinglong decoction combined with noninvasive ventilator could significantly reduce the procalcitonin level, effectively improve the respiratory function and blood gas analysis indexes, and significantly reduce the clinical symptoms in AECOPD patients, so it is worthy of promotion.
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Ventilação não Invasiva , Doença Pulmonar Obstrutiva Crônica , Gasometria , Humanos , Pró-Calcitonina , Testes de Função RespiratóriaRESUMO
BACKGROUND/AIMS: p53 dysfunction is frequently observed in lung cancer. Although restoring the tumour suppressor function of p53 is recently approved as a putative strategy for combating cancers, the lack of understanding of the molecular mechanism underlying p53-mediated lung cancer suppression has limited the application of p53-based therapies in lung cancer. METHODS AND RESULTS: Using RNA sequencing, we determined the transcriptional profile of human non-small cell lung carcinoma A549 cells after treatment with two p53-activating chemical compounds, nutlin and RITA, which could induce A549 cell cycle arrest and apoptosis, respectively. Bioinformatics analysis of genome-wide gene expression data showed that distinct transcription profiles were induced by nutlin and RITA and 66 pathways were differentially regulated by these two compounds. However, only two of these pathways, 'Adherens junction' and 'Axon guidance', were found to be synthetic lethal with p53 re-activation, as determined via integrated analysis of genome-wide gene expression profile and short hairpin RNA (shRNA) screening. Further functional protein association analysis of significantly regulated genes associated with these two synthetic lethal pathways indicated that GSK3 played a key role in p53-mediated A549 cell apoptosis, and then gene function study was performed, which revealed that GSK3 inhibition promoted p53-mediated A549 cell apoptosis in a p53 post-translational activity-dependent manner. CONCLUSION: Our findings provide us with new insights regarding the mechanism by which p53 mediates A549 apoptosis and may cast light on the development of more efficient p53-based strategies for treating lung cancer.
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Apoptose , Carcinoma Pulmonar de Células não Pequenas/genética , Quinase 3 da Glicogênio Sintase/genética , Neoplasias Pulmonares/genética , Pulmão/patologia , Proteína Supressora de Tumor p53/genética , Células A549 , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Pontos de Checagem do Ciclo Celular , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Pulmão/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Transcriptoma , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND/AIMS: Osteopontin (OPN) is an Extracellular Matrix (ECM) molecule and is involved in many physiologic and pathologic processes, including cell adhesion, angiogenesis and tumor metastasis. OPN is a well-known multifunctional factor involved in various aspects of cancer progression, including endometrial cancer. In this study, we examined the significance of OPN in endometrial cancer. METHODS: The proliferation, migration and invasion ability of HEC-1A cells were detected by Cell Counting Kit-8 (CCK-8), Wound scratch assay and transwell. Western blots were employed to detect the expression of Matrix metalloproteinase-2 (MMP-2) and epithelial-mesenchymal transition (EMT)-related factors in HEC-1A cells treated with rhOPN. RESULTS: rhOPN promotes cell proliferation, migration and invasion in HEC-1A cells. rhOPN influenced EMT-related factors and MMP-2 expression in HEC-1A cells. rhOPN promoted HEC-1A cells migration, invasion and EMT through protein kinase B (PKB/AKT) and Extracellular regulated protein kinases (ERK1/2) signaling pathway. CONCLUSIONS: These results may open up a novel therapeutic strategy for endometrial cancer: namely, rhOPN have important roles in controlling growth of endometrial of cancer cells and suggest a novel target pathway for treatment of this cancer.
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Transição Epitelial-Mesenquimal/efeitos dos fármacos , Osteopontina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Butadienos/farmacologia , Caderinas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromonas/farmacologia , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Morfolinas/farmacologia , Nitrilas/farmacologia , Osteopontina/genética , Osteopontina/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Vimentina/metabolismoRESUMO
This study evaluated antioxidant and antimicrobial properties of chitosan gel (Cs-gel) functionalized with cinnamaldehyde oil (CN) and orange peel-derived flavonoid extract (Fs) using the ionic-gelation method. Results showed that the encapsulation efficiencies of CCF-9 and CCN were 83.14 ± 3.34 and 80.56 ± 1.17%, respectively. The interaction of CN or Fs on Cs-gel indicates the presence of H-bonding formation, as observed by UV-vis spectroscopy, Fourier transform infrared spectrophotometry (FTIR), and Raman-spectroscopy showed a good corroboration with Surflex-dock findings. Scanning electron microscopy also showed the integration that occurred between Cs and both ligands, which was further supported with X-ray diffraction and X-Ray photoelectron spectroscopy spectra. The textural properties of CCF-5 gel showed high hardness, chewiness, and gumminess values, indicating that the integration of Fs and CN altered the microstructure of Cs-gel. Chotison-functionalized based gels exhibited higher antioxidant abilities against DPPH and ABTS free radicals than Cs-gel. The CCF-9 gel showed a good inhibition value of 29.91 ± 1.22 and 93.61 ± 2.12% against Penicillium expansum and Alternaria westerdijkiae, respectively. Additionally, CCF-9 inhibition zones against Staphylococcus aureus, Escherichia coli, and Bacillus cerues were 28.65 ± 0.05, 27.69 ± 0.04, and 26.16 ± 0.02 mm, respectively. These findings demonstrated the potential antioxidant and antimicrobial effects of functionalized chitosan gel indicating its potential as a bioactive additive for food preservation.
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Aspergillus westerdijkiae can infect many agricultural products including cereals, grapes, and pear. Pathogenic fungi secrete diverse effectors as invasive weapons for successful invasion the host plant. During the pathogen-host interaction, 4486 differentially expressed genes were observed in A. westerdijkiae with 2773 up-regulated and 1713 down-regulated, whereas 8456 differentially expressed genes were detected in pear fruits with 4777 up-regulated and 3679 down-regulated. A total of 309 effector candidate genes were identified from the up-regulated genes in A. westerdijkiae. Endoglucanase H (AwEGH) was significantly induced during the pathogen-host interaction. Deletion of AwEGH resulted in altered fungal growth and morphology and reduced conidia production and germination compared to the wild-type. Further experiments demonstrated that AwEGH plays a role in cell wall integrity. Importantly, disruption of AwEGH significantly reduced the fungal virulence on pear fruits, and this defect can be partly explained by the impaired ability of A. westerdijkiae to penetrate host plants.
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Aspergillus , Celulase , Pyrus , Pyrus/genética , Celulase/genética , Virulência , Frutas/genética , Proteínas Fúngicas/genéticaRESUMO
Chitosan is a natural polysaccharide that is abundant, biocompatible and exhibits effective antifungal activity against various pathogenic fungi. However, the potential intracellular targets of chitosan in pathogenic fungi and the way of activity of chitosan are far from well known. The present work demonstrated that chitosan could inhibit Penicillium expansum, the principal causal agent of postharvest blue mold decay on apple fruits, by binding to DNA and triggering apoptosis. UV-visible spectroscopy, fluorescence spectroscopy and electrophoretic mobility assay proved the interaction between chitosan and DNA, while atomic force microscope (AFM) observation revealed the binding morphology of chitosan to DNA. Chitosan could inhibit in vitro DNA replication, and cell cycle analysis employing flow cytometry demonstrated that cell cycle was retarded by chitosan treatment. Furthermore, the reactive oxygen species (ROS) assay and membrane potential analysis showed that apoptosis was induced in P. expansum cells after exposure to chitosan. In conclusion, our results confirmed that chitosan interacts with DNA and induces apoptosis. These findings are expected to provide a feasible theoretical basis and practical direction for the promoting and implementing of chitosan in plant protection and further illuminate the possible antifungal mechanisms of chitosan against fungal pathogens.
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Quitosana , Malus , Penicillium , Antifúngicos/farmacologia , Quitosana/farmacologia , Penicillium/genética , Frutas , DNA/farmacologiaRESUMO
Learning-based surface reconstruction based on unsigned distance functions (UDF) has many advantages such as handling open surfaces. We propose SuperUDF, a self-supervised UDF learning which exploits a learned geometry prior for efficient training and a novel regularization for robustness to sparse sampling. The core idea of SuperUDF draws inspiration from the classical surface approximation operator of locally optimal projection (LOP). The key insight is that if the UDF is estimated correctly, the 3D points should be locally projected onto the underlying surface following the gradient of the UDF. Based on that, a number of inductive biases on UDF geometry and a pre-learned geometry prior are devised to learn UDF estimation efficiently. A novel regularization loss is proposed to make SuperUDF robust to sparse sampling. Furthermore, we also contribute a learning-based mesh extraction from the estimated UDFs. Extensive evaluations demonstrate that SuperUDF outperforms the state of the arts on several public datasets in terms of both quality and efficiency. Code will be released after accteptance.
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Background: Colorectal cancer (CRC) is a heterogeneous cancer. Its treatment depends on its anatomical site and molecular features. Carcinomas of the rectosigmoid junction are frequent; however, specific data on these tumors are sparse, as they are frequently assigned to either the colon or rectum. This study sought to identify the molecular features of rectosigmoid junction cancer to determine whether there should be any difference between the therapeutic management of rectosigmoid junction cancer and that of sigmoid colon or rectum cancer. Methods: The data of 96 CRC patients with carcinomas in the sigmoid colon, rectosigmoid junction, and rectum were retrospectively summarized. The next-generation sequencing (NGS) data of the patients were analyzed to study the molecular characteristics of the carcinomas in different locations of the bowel. Results: In total, there was no difference in the clinicopathologic characteristics of the three groups. TP53, APC, and KRAS genes were the top 3 alteration genes in sigmoid colon, rectosigmoid junction, and rectum cancer. The rates of the KRAS, NRAS, and PIK3CA increased as the location moved distally, while the rates of APC and BRAF decreased. Almost no significant molecular differences were found among the three groups. The prevalence of the FLT3, fms-related tyrosine kinase 1 (FLT1), and phosphoenolpyruvate carboxykinase 1 (PCK1) mutation was lower in the rectosigmoid junction group than the sigmoid colon and rectum groups (P>0.05). The proportion of the transforming growth factor beta pathway was higher in the rectosigmoid junction and rectum groups than the sigmoid colon group (39.3% vs. 34.3% vs. 18.2%, respectively, P=0.121, P=0.067, P=0.682); a higher proportion of MYC pathway was also observed in the rectosigmoid junction than that in rectum and sigmoid colon (28.6% vs. 15.2% vs. 17.1%, P=0.278, P=0.202, P=0.171). Regardless of the clustering method employed, the patients were divided into two clusters, and the composition of clusters revealed no significant differences in terms of the different locations. Conclusions: Rectosigmoid junction cancer has a distinctive molecular profile compared to the molecular profiles of the adjacent bowel segment cancers.
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The efficiency of drug biosynthesis depends on different transcriptional regulatory pathways in Streptomyces, and the protein degradation system adds another layer of complexity to the regulatory processes. AtrA, a transcriptional regulator in the A-factor regulatory cascade, stimulates the production of daptomycin by binding to the dptE promoter in Streptomyces roseosporus. Using pull-down assays, bacterial two-hybrid system and knockout verification, we demonstrated that AtrA is a substrate for ClpP protease. Furthermore, we showed that ClpX is necessary for AtrA recognition and subsequent degradation. Bioinformatics analysis, truncating mutation, and overexpression proved that the AAA motifs of AtrA were essential for initial recognition in the degradation process. Finally, overexpression of mutated atrA (AAA-QQQ) in S. roseosporus increased the yield of daptomycin by 225% in shake flask and by 164% in the 15 L bioreactor. Thus, improving the stability of key regulators is an effective method to promote the ability of antibiotic synthesis.
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Daptomicina , Streptomyces , Daptomicina/metabolismo , Antibacterianos/metabolismo , Regiões Promotoras Genéticas , Mutação , Tretinoína/metabolismo , Streptomyces/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismoRESUMO
BACKGROUND: Chemotherapy is the main treatment strategy for patients with advanced HER2-negative gastric cancer (GC); yet, many patients do not respond well to treatment. This study evaluated the sensitivity of a mini patient-derived xenograft (MiniPDX) animal model in patients with HER2-negative intermediate-advanced GC. METHODS: In this single-arm, open-label clinical study, we consecutively recruited patients with HER2-negative advanced or recurrent GC from September 2018 to July 2021. Tumor tissues were subjected to MiniPDX drug sensitivity tests for screening individualized anti-tumor drugs; appropriate drug types or combinations were selected based on drug screening results. The primary endpoints were progression-free survival (PFS) and safety, and the secondary endpoints were overall survival (OS) and objective response rate (ORR). RESULTS: A total of 17 patients were screened, and 14 eligible patients were included.The median follow-up time was 9 (2-34) months. The median PFS time was 14.1 (2-34) months, the median OS time was 16.9 (2-34) months, ORR was 42.9% (6/14), and DCR was 92.9% (13/14). The most common treatment-related adverse events (TRAE) were fatigue (14 (100%)), anorexia (13 (93%)) and insomnia (12 (86%)), and the most common grade 3 or worse TRAE was fatigue (6 (43%)), and anorexia (6 (43%)). The occurrence rate of myelosuppression, nausea and vomiting, abnormal liver enzymes, and other grade 3-4 chemotherapy adverse reactions were relatively low, and no grade 5 treatment-related adverse events occurred. CONCLUSION: Screening HER2-negative medium-advanced GC/GJC chemotherapy regimens and targeted drugs based on MiniPDX animal models showed good tumor activity and safety.
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Background: As an antidiabetic agent, sotagliflozin was recently approved for heart failure (HF). However, its cardiovascular benefits in type 2 diabetic mellitus (T2DM) patients with HF or cardiovascular (CV) risk factors have not been systematically evaluated. The aim of this study is to evaluate the cardiovascular benefits and safety of sotagliflozin in T2DM patients with HF or CV risk factors using Bayesian network meta-analysis. Methods: Data were retrieved from PubMed, Embase, Web of Science, ClinicalTrials.gov, and Cochrane Library from their inception to 16 August 2023. Randomized controlled trials (RCTs) comparing sotagliflozin with a placebo, dapagliflozin, and empagliflozin in adult T2DM patients with HF or CV risks for at least 12 weeks were included in the study. Data analysis was conducted using R 4.2.3 and Stata 17.0. Cardiovascular efficacy outcomes included HF events (hospitalization or urgent visits for HF), MACE (deaths from CV causes, hospitalizations for HF, nonfatal myocardial infarctions, and strokes), cardiovascular death, the decrease in SBP, and weight loss. Safety outcomes are urinary tract infection, diarrhea, and diabetic ketoacidosis. Results: Eleven studies with 30,952 patients were included. Compared to dapagliflozin and empagliflozin, 200 mg of sotagliflozin showed the best effect in reducing HF events [OR (95% CI), 0.79 (0.66, 0.94) and 0.90 (0.63, 1.27)]. Compared to dapagliflozin, 200 mg of sotagliflozin [OR (95% CI), 0.76 (0.66, 0.87)] was superior in preventing MACE. Compared to empagliflozin, 200 mg of sotagliflozin [OR (95% CI), 1.46 (1.04, 2.05)] was inferior in preventing CV death. Sotagliflozin showed a poorer SBP decreasing effect than empagliflozin and dapagliflozin [MD (95% CI), 1.30 (0.03, 2.56) and 2.25 (0.35, 4.14), respectively]. There was no significant difference between sotagliflozin and other interventions in weight loss. Sotagliflozin exhibited no increased risk for diabetic ketoacidosis or urinary tract infection among all interventions, however, it showed a mild risk for diarrhea than placebo [OR (95% CI), 1.47 (1.28, 1.69)]. Conclusion: Sotagliflozin displayed moderate CV benefits and acceptable safety. Sotagliflozin can be one of the recommended options for T2DM patients with HF or CV risk factors, which will be important for evidence-based use of sotagliflozin as well as decision-making of T2DM medication.
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DNA methylation is a defense that microorganisms use against extreme environmental stress, and improving resistance against environmental stress is essential for industrial actinomycetes. However, research on strain optimization utilizing DNA methylation for breakthroughs is rare. Based on DNA methylome analysis and KEGG pathway assignment in Streptomyces roseosporus, we discovered an environmental stress resistance regulator, TagR. A series of in vivo and in vitro experiments identified TagR as a negative regulator, and it is the first reported regulator of the wall teichoic acid (WTA) ABC transport system. Further study showed that TagR had a positive self-regulatory loop and m4C methylation in the promoter improved its expression. The ΔtagR mutant exhibited better hyperosmotic resistance and higher decanoic acid tolerance than the wild type, which led to a 100% increase in the yield of daptomycin. Moreover, enhancing the expression of the WTA transporter resulted in better osmotic stress resistance in Streptomyces lividans TK24, indicating the potential for wide application of the TagR-WTA transporter regulatory pathway. This research confirmed the feasibility and effectiveness of mining regulators of environmental stress resistance based on the DNA methylome, characterized the mechanism of TagR, and improved the resistance and daptomycin yield of strains. Furthermore, this research provides a new perspective on the optimization of industrial actinomycetes. IMPORTANCE This study established a novel strategy for screening regulators of environmental stress resistance based on the DNA methylome and discovered a new regulator, TagR. The TagR-WTA transporter regulatory pathway improved the resistance and antibiotic yield of strains and has the potential for wide application. Our research provides a new perspective on the optimization and reconstruction of industrial actinomycetes.