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1.
Nat Commun ; 15(1): 3832, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714720

RESUMO

Herein, we develop a straightforward, metal-free, and acid-/base-free electrochemical C4-selective C - H deuteration of pyridine derivatives with economic and convenient D2O at room temperature. This strategy features an efficient and environmentally friendly approach with high chemo- and regioselectivity, affording a wide range of D-compounds, such as pyridines, quinolones, N-ligands and biorelevant compounds. Notably, the mechanistic experiments and cyclic voltammetry (CV) studies demonstrate that N-butyl-2-phenylpyridinium iodide is a crucial intermediate during the electrochemical transformation, which provides a general and efficient way for deuteration of pyridine derivatives.

2.
Nano Lett ; 24(20): 6061-6068, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38728017

RESUMO

van der Waals (vdW) superlattices, comprising different 2D materials aligned alternately by weak interlayer interactions, offer versatile structures for the fabrication of novel semiconductor devices. Despite their potential, the precise control of optoelectronic properties with interlayer interactions remains challenging. Here, we investigate the discrepancies between the SnS/TiS2 superlattice (SnTiS3) and its subsystems by comprehensive characterization and DFT calculations. The disappearance of certain Raman modes suggests that the interactions alter the SnS subsystem structure. Specifically, such structural changes transform the band structure from indirect to direct band gap, causing a strong PL emission (∼2.18 eV) in SnTiS3. In addition, the modulation of the optoelectronic properties ultimately leads to the unique phenomenon of thermally activated photoluminescence. This phenomenon is attributed to the inhibition of charge transfer induced by tunable intralayer strains. Our findings extend the understanding of the mechanism of interlayer interactions in van der Waals superlattices and provide insights into the design of high-temperature optoelectronic devices.

3.
Respir Res ; 25(1): 186, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678295

RESUMO

BACKGROUND: Influenza A viruses (IAV) are extremely common respiratory viruses for the acute exacerbation of chronic obstructive pulmonary disease (AECOPD), in which IAV infection may further evoke abnormal macrophage polarization, amplify cytokine storms. Melatonin exerts potential effects of anti-inflammation and anti-IAV infection, while its effects on IAV infection-induced AECOPD are poorly understood. METHODS: COPD mice models were established through cigarette smoke exposure for consecutive 24 weeks, evaluated by the detection of lung function. AECOPD mice models were established through the intratracheal atomization of influenza A/H3N2 stocks in COPD mice, and were injected intraperitoneally with melatonin (Mel). Then, The polarization of alveolar macrophages (AMs) was assayed by flow cytometry of bronchoalveolar lavage (BAL) cells. In vitro, the effects of melatonin on macrophage polarization were analyzed in IAV-infected Cigarette smoking extract (CSE)-stimulated Raw264.7 macrophages. Moreover, the roles of the melatonin receptors (MTs) in regulating macrophage polarization and apoptosis were determined using MTs antagonist luzindole. RESULTS: The present results demonstrated that IAV/H3N2 infection deteriorated lung function (reduced FEV20,50/FVC), exacerbated lung damages in COPD mice with higher dual polarization of AMs. Melatonin therapy improved airflow limitation and lung damages of AECOPD mice by decreasing IAV nucleoprotein (IAV-NP) protein levels and the M1 polarization of pulmonary macrophages. Furthermore, in CSE-stimulated Raw264.7 cells, IAV infection further promoted the dual polarization of macrophages accompanied with decreased MT1 expression. Melatonin decreased STAT1 phosphorylation, the levels of M1 markers and IAV-NP via MTs reflected by the addition of luzindole. Recombinant IL-1ß attenuated the inhibitory effects of melatonin on IAV infection and STAT1-driven M1 polarization, while its converting enzyme inhibitor VX765 potentiated the inhibitory effects of melatonin on them. Moreover, melatonin inhibited IAV infection-induced apoptosis by suppressing IL-1ß/STAT1 signaling via MTs. CONCLUSIONS: These findings suggested that melatonin inhibited IAV infection, improved lung function and lung damages of AECOPD via suppressing IL-1ß/STAT1-driven macrophage M1 polarization and apoptosis in a MTs-dependent manner. Melatonin may be considered as a potential therapeutic agent for influenza virus infection-induced AECOPD.


Assuntos
Apoptose , Vírus da Influenza A Subtipo H3N2 , Melatonina , Doença Pulmonar Obstrutiva Crônica , Animais , Melatonina/farmacologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/virologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Camundongos , Apoptose/efeitos dos fármacos , Células RAW 264.7 , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/metabolismo , Infecções por Orthomyxoviridae/imunologia , Camundongos Endogâmicos C57BL , Masculino , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Progressão da Doença , Polaridade Celular/efeitos dos fármacos , Modelos Animais de Doenças , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/virologia
4.
Cancers (Basel) ; 16(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38339238

RESUMO

Background: Small Cajal body-specific RNAs (scaRNAs) are a specific subset of small nucleolar RNAs (snoRNAs) that have recently emerged as pivotal contributors in diverse physiological and pathological processes. However, their defined roles in carcinogenesis remain largely elusive. This study aims to explore the potential function and mechanism of SCARNA12 in bladder cancer (BLCA) and to provide a theoretical basis for further investigations into the biological functionalities of scaRNAs. Materials and Methods: TCGA, GEO and GTEx data sets were used to analyze the expression of SCARNA12 and its clinicopathological significance in BLCA. Quantitative real-time PCR (qPCR) and in situ hybridization were applied to validate the expression of SCARNA12 in both BLCA cell lines and tissues. RNA sequencing (RNA-seq) combined with bioinformatics analyses were conducted to reveal the changes in gene expression patterns and functional pathways in BLCA patients with different expressions of SCARNA12 and T24 cell lines upon SCARNA12 knockdown. Single-cell mass cytometry (CyTOF) was then used to evaluate the tumor-related cell cluster affected by SCARNA12. Moreover, SCARNA12 was stably knocked down in T24 and UMUC3 cell lines by lentivirus-mediated CRISPR/Cas9 approach. The biological effects of SCARNA12 on the proliferation, clonogenic, migration, invasion, cell apoptosis, cell cycle, and tumor growth were assessed by in vitro MTT, colony formation, wound healing, transwell, flow cytometry assays, and in vivo nude mice xenograft models, respectively. Finally, a chromatin isolation by RNA purification (ChIRP) experiment was further conducted to delineate the potential mechanisms of SCARNA12 in BLCA. Results: The expression of SCARNA12 was significantly up-regulated in both BLCA tissues and cell lines. RNA-seq data elucidated that SCARAN12 may play a potential role in cell adhesion and extracellular matrix (ECM) related signaling pathways. CyTOF results further showed that an ECM-related cell cluster with vimentin+, CD13+, CD44+, and CD47+ was enriched in BLCA patients with high SCARNA12 expression. Additionally, SCARNA12 knockdown significantly inhibited the proliferation, colony formation, migration, and invasion abilities in T24 and UMUC3 cell lines. SCARNA12 knockdown prompted cell arrest in the G0/G1 and G2/M phase and promoted apoptosis in T24 and UMUC3 cell lines. Furthermore, SCARNA12 knockdown could suppress the in vivo tumor growth in nude mice. A ChIRP experiment further suggested that SCARNA12 may combine transcription factors H2AFZ to modulate the transcription program and then affect BLCA progression. Conclusions: Our study is the first to propose aberrant alteration of SCARNA12 and elucidate its potential oncogenic roles in BLCA via the modulation of ECM signaling. The interaction of SCARNA12 with the transcriptional factor H2AFZ emerges as a key contributor to the carcinogenesis and progression of BLCA. These findings suggest SCARNA12 may serve as a diagnostic biomarker and potential therapeutic target for the treatment of BLCA.

5.
Aging (Albany NY) ; 16(3): 2542-2562, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38305811

RESUMO

The H2A.Z variant histone 1 (H2AZ1) is aberrantly expressed in various tumors, correlating with an unfavorable prognosis. However, its role in hepatocellular carcinoma (HCC) remains unclear. We aimed to elucidate the pathways affected by H2AZ1 and identify promising therapeutic targets for HCC. Following bioinformatic analysis of gene expression and clinical data from The Cancer Genome Atlas and Gene Expression Omnibus database, we found 6,344 dysregulated genes related to H2AZ1 overexpression in HCC tissues (P < 0.05). We performed weighted gene co-expression network analysis to identify the gene module most related to H2AZ1. The H2AZ1-based index was further developed using Cox regression analysis, which revealed that the poor prognosis in the high H2AZ1-based index group could be attributed to elevated tumor stemness (P < 0.05). Moreover, the clinical model showed good prognostic potential (AUC > 0.7). We found that H2AZ1 knockdown led to reduced superoxide dismutase (SOD) activity, elevated malondialdehyde (MDA) levels, and increased apoptosis rate in tumor cells (P < 0.001). Thus, we developed an H2AZ1-based index model with the potential to predict the prognosis of patients with HCC. Our findings provide initial evidence that H2AZ1 overexpression plays a pivotal role in HCC initiation and progression.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Cognição , Histonas , Neoplasias Hepáticas/genética , Prognóstico
6.
J Pediatr Surg ; 59(4): 653-659, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38182535

RESUMO

PURPOSE: There is no standard surgical approach for pancreaticobiliary maljunction (PBM) without congenital biliary dilatation (CBD). This study aimed to compare outcomes between therapeutic endoscopic retrograde cholangiopancreatography (ERCP) and laparoscopic hepaticojejunostomy (LH) for pediatric patients of PBM without obvious biliary dilatation (PBM-nonOBD). METHODS: We retrospectively reviewed demographic and clinical data of pediatric patients with PBM-nonOBD from 2015 to 2021. There were 33 patients in ERCP group and 35 patients in LH group. Primary outcomes included treatment efficiency, postoperative recovery, and postoperative complications. Univariate analysis was further used to explore prognostic factors for ERCP. RESULTS: The mean diameter of the common bile duct in LH group was larger than that in ERCP group (8.6 ± 1.3 mm vs. 6.9 ± 2.1 mm, p = 0.003), while there were no significant differences between the two groups in age, gender, clinical manifestations, complications, and other imaging findings. Compared with LH group, ERCP group had a shorter operation time and postoperative recovery time. The treatment effective rate of ERCP was inferior to that of LH (45.4 % vs. 85.7 %, p<0.001). For postoperative adverse events, post-ERCP pancreatitis (15.1 %) was most common in the ERCP group. 30.3 % of patients eventually required LH. Intestinal obstruction (5.7 %), recurrent cholangitis (5.7 %), gastrointestinal bleeding (2.8 %), and anastomotic stenosis (2.8 %) were observed in LH group and 8.6 % of patients required a reoperation. A long common channel may be associated with poor prognosis after ERCP. CONCLUSIONS: ERCP is associated with less surgical trauma, shorter recovery time, and fewer serious complications than LH, while the treatment effective rate of ERCP is inferior to LH. The indications for endoscopic sphincterotomy and the timing of radical surgery need to be further explored. LEVEL OF EVIDENCE: Ⅲ STUDY TYPE: Retrospective Comparative Study.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Má Junção Pancreaticobiliar , Humanos , Criança , Colangiopancreatografia Retrógrada Endoscópica/métodos , Estudos Retrospectivos , Dilatação/métodos , Má Junção Pancreaticobiliar/etiologia , Esfinterotomia Endoscópica/efeitos adversos
7.
Ann Hematol ; 103(3): 999-1005, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38285081

RESUMO

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare hematologic malignancy that is highly aggressive with a poor prognosis. There is no standard treatment for BPDCN. Although conventional chemotherapies are usually sensitive in the initial therapy, relapse and drug resistance are inevitable within a short duration. Targeted therapies have enlightened new prospects for the treatment of BPDCN, especially for those in a frail state and intolerable to standard chemotherapies or hematopoietic stem cell transplantation. Here, we report an 82-year-old man diagnosed with cutaneous-limited BPDCN. Considering the old age and limited involvement of the tumor, we reduced the dosage of venetoclax. His skin lesions subsided significantly after 1 cycle of azacytidine (100 mg d1-7) combined with reduced doses of venetoclax (200 mg d1-14). The reduction in the dose of venetoclax avoided severe myelosuppression while achieving satisfactory outcomes. The patient received 2 cycles of therapy with no skin lesions re-occurred for 7 months before relapsing.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Neoplasias Hematológicas , Transtornos Mieloproliferativos , Neoplasias Cutâneas , Sulfonamidas , Masculino , Humanos , Idoso de 80 Anos ou mais , Azacitidina/uso terapêutico , Células Dendríticas/patologia , Recidiva Local de Neoplasia/tratamento farmacológico , Neoplasias Cutâneas/patologia , Neoplasias Hematológicas/terapia , Transtornos Mieloproliferativos/patologia
8.
PLoS One ; 19(1): e0292082, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38271369

RESUMO

An essential industrial application is the examination of surface flaws in hot-rolled steel strips. While automatic visual inspection tools must meet strict real-time performance criteria for inspecting hot-rolled steel strips, their capabilities are constrained by the accuracy and processing speed of the algorithm used to identify defects. To solve the problems of poor detection accuracy, low detection efficiency, and unsuitability of low computing power platforms of the hot-rolled strip surface defect detection algorithm The Swin-Transformer-YOLOv5 model based on the improved one-stage detector is proposed. By employing GhostNet, the model's lightweight design, and guaranteed detection accuracy are both achieved. The C3 module introduces Swin-Transformer to address the issues of cluttered backdrops of defect photos and easily confused defect categories. With the addition of the CoordAttention module, the model's capacity to extract defective features is improved, and its performance keeps getting better. The issue of huge differences in different scales and poor detection of small flaws is resolved by employing BiFPN for feature fusion, and the detector's capacity to adapt to targets of different scales is improved. The experimental results demonstrate that the improved Swin-Transformer-Yolov5 model significantly outperforms the industry-standard target detection algorithms, and the model's mAP value still improves by 8.39% over the original model while reducing the number of parameters, GFLOPs, and weight by 36.6%, 40.0%, and 34.7%, respectively. The model is better suited for use on low-arithmetic platforms as a result.


Assuntos
Algoritmos , Exame Físico , Humanos , Confusão , Fontes de Energia Elétrica , Aço
9.
Cell Signal ; 116: 111032, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38185228

RESUMO

Universal stress proteins are a class of proteins widely present in bacteria, archaea, plants, and invertebrates, playing essential roles in bacterial adaptation to various environmental stresses. The functions of bacterial universal stress proteins are versatile, including resistance to oxidative stress, maintenance of cell wall integrity, DNA damage repair, regulation of cell division and growth, among others. When facing stresses such as temperature changes, pH shifts, fluctuations in oxygen concentration, and exposure to toxins, these proteins can bind to specific DNA sequences and rapidly adjust bacterial metabolic pathways and gene expression patterns to adapt to the new environment. In summary, bacterial universal stress proteins play a crucial role in bacterial adaptability and survival. A comprehensive understanding of bacterial stress response mechanisms and the development of new antibacterial strategies are of great significance. This review summarizes the research progress on the structure, function, and regulatory factors of universal stress proteins in clinically relevant bacteria, aiming to facilitate deeper investigations by clinicians and researchers into universal stress proteins.


Assuntos
Bactérias , Proteínas de Choque Térmico , Bactérias/genética , Archaea , Proteínas de Bactérias/genética , Antibacterianos
10.
Hepatol Int ; 18(1): 73-90, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159218

RESUMO

PURPOSE: Cytokeratin 19-positive cancer stem cells (CK19 + CSCs) and their tumor-associated macrophages (TAMs) have not been fully explored yet in the hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). EXPERIMENTAL DESIGN: Single-cell RNA sequencing was performed on the viable cells obtained from 11 treatment-naïve HBV-associated HCC patients, including 8 CK19 + patients, to elucidate their transcriptomic landscape, CK19 + CSC heterogeneity, and immune microenvironment. Two in-house primary HCC cohorts (96 cases-related HBV and 89 cases with recurrence), TCGA external cohort, and in vitro and in vivo experiments were used to validate the results. RESULTS: A total of 64,581 single cells derived from the human HCC and adjacent normal tissues were sequenced, and 11 cell types were identified. The result showed that CK19 + CSCs were phenotypically and transcriptionally heterogeneous, co-expressed multiple hepatics CSC markers, and were positively correlated with worse prognosis. Moreover, the SPP1 + TAMs (TAM_SPP1) with strong M2-like features and worse prognosis were specifically enriched in the CK19 + HCC and promoted tumor invasion and metastasis by activating angiogenesis. Importantly, matrix metalloproteinase 9 (MMP9) derived from TAM_SPP1, as the hub gene of CK19 + HCC, was activated by the VEGFA signal. CONCLUSIONS: This study revealed the heterogeneity and stemness characteristics of CK19 + CSCs and specific immunosuppressive TAM_SPP1 in CK19 + HCC. The VEGFA signal can activate TAM_SPP1-derived MMP9 to promote the invasion and metastasis of CK19 + HCC tumors. This might provide novel insights into the clinical treatment of HCC patients.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Vírus da Hepatite B/genética , Metaloproteinase 9 da Matriz/genética , Queratina-19/genética , Queratina-19/metabolismo , Macrófagos Associados a Tumor/metabolismo , Macrófagos Associados a Tumor/patologia , Células-Tronco Neoplásicas , Análise de Sequência de RNA , Microambiente Tumoral , Osteopontina/genética , Osteopontina/metabolismo
11.
Exp Lung Res ; 49(1): 220-230, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38047519

RESUMO

Background: Sepsis has become one of the main factors inducing the development of acute lung injury (ALI) in clinical practice. Currently, inhibiting the activation of NLRP3 mediated pyroptosis is the target of multiple drugs in the treatment of sepsis induced ALI. This study aimed to explore the effects of METTL14 on the pyroptosis in the sepsis induced ALI progression.Methods: LPS-stimulated A549 cells and cecal ligation and puncture (CLP)-treated mice were used to establish the ALI model in vitro and in vivo. Then, the cell viability was measured by CCK-8 assay. ELISA kits were used to determine the IL-18 and IL-1ß contents. Pyroptosis rate was tested by flow cytometry. M6A dot blot was conducted to analyze the global m6A levels and MeRIP assay was performed to detect the m6A levels of NLRP3. The relationship between METTL14 and NLRP3 was confirmed by RIP and dual-luciferase report assays.Results: The global m6A levels were significantly increased in the LPS-stimulated A549 cells and CLP-treated mice. METTL14 knockdown decreased the cell viability, IL-18 and IL-1ß contents, and pyroptosis rate of the LPS-stimulated A549 cells. Furthermore, the increase of pyroptosis-related proteins in LPS-stimulated A549 cells was significantly decreased after METTL14 knockdown. Additionally, METTL14 knockdown decreased the m6A and mRNA levels of NLRP3, and NLRP3 overexpression reversed the effects of METTL14 knockdown on the pyroptosis in the LPS-stimulated A549 cells. In CLP-treated mice, METTL14 knockdown relieved the injury and decreased the IL-18 and IL-1ß contents in the lung tissues, serum and bronchoalveolar lavage fluid.Conclusion: This study demonstrated that METTL14 knockdown inhibited the pyroptosis in the sepsis-induced ALI progression through decreasing the NLRP3 levels dependent on m6A methylation modification.


Assuntos
Lesão Pulmonar Aguda , Sepse , Animais , Camundongos , Lesão Pulmonar Aguda/induzido quimicamente , Interleucina-18/efeitos adversos , Lipopolissacarídeos/efeitos adversos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose , Sepse/complicações
12.
J Gastroenterol ; 58(12): 1167-1177, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37777987

RESUMO

BACKGROUND: The application of vonoprazan significantly improved the eradication rate of Helicobacter pylori (H. pylori). This study aimed to compare efficacy and safety of the 10-day vonoprazan-amoxicillin (VA) and 14-day rabeprazole-amoxicillin (RA) dual therapy, and to provide a more efficient, safer, and convenient dual regimen for H. pylori infection. METHODS: This was a prospective, open-label, multi-center, randomized controlled study of treatment-naive patients with H. pylori infection. The participants were randomly assigned to the 10-day VA group with vonoprazan 20 mg Bid plus amoxicillin 1 g Tid or the 14-day RA group with rabeprazole 10 mg Tid plus amoxicillin 1 g Tid. The effectiveness, the adverse events, and the patient compliance of the two groups were compared. RESULTS: A total of 690 patients were enrolled. The eradication rates of 10-day VA and 14-day RA dual therapy were 89.3% and 84.9% in intention-to-treat (ITT) analysis (P = 0.088); 90.6% and 85.9% by modified intention-to-treat (mITT) analysis (P = 0.059); 91.4% and 86.6% by per-protocol (PP) analysis (P = 0.047). Non-inferiority was confirmed between the two groups (all P < 0.001). No discernible differences were observed in adverse effects and compliance between groups. Poor compliance reduced the eradication efficacy (P < 0.05). CONCLUSIONS: The 10-day VA dual therapy was non-inferior to the 14-day RA dual therapy for H. pylori treatment-naive patients, which should be given priority in the first-line treatment. The application of vonoprazan reduced treatment course and antibiotic use. Patients' adherence was crucial for the success of eradication.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Humanos , Infecções por Helicobacter/tratamento farmacológico , Rabeprazol/efeitos adversos , Estudos Prospectivos , Inibidores da Bomba de Prótons/efeitos adversos , Claritromicina/uso terapêutico , Quimioterapia Combinada , Antibacterianos/efeitos adversos , Amoxicilina/efeitos adversos , Resultado do Tratamento
13.
Nat Commun ; 14(1): 6467, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833286

RESUMO

Herein, a metal-free electrochemical dihydroxylation of unactivated alkenes is described. The transformation proceeds smoothly under mild conditions with a broad range of unactivated alkenes, providing valuable and versatile dihydroxylated products in moderate to good yields without the addition of costly transition metals and stoichiometric amounts of chemical oxidants. Moreover, this method can be applied to a range of natural products and pharmaceutical derivatives, further demonstrating its synthetic utility. Mechanistic studies have revealed that iodohydrin and epoxide intermediate are formed during the reaction process.

14.
Appl Microbiol Biotechnol ; 107(23): 7089-7104, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37733049

RESUMO

Nitriles are of significant interest in the flavor and fragrance industries with potential application in cosmetics due to their higher stability than analogous aldehydes. However, the traditional methods to prepare nitriles need toxic reagents and hash conditions. This work aimed to develop a chemoenzymatic strategy to synthesize nitriles from natural aldehydes with aldoxime as the intermediate. A non-classical aldoxime dehydratase (Oxd) was discovered from the fungus Aspergillus ibericus (OxdAsp) to catalyze the dehydration of aldoximes to corresponding nitriles under mild conditions. The amino acid sequence of OxdAsp exhibits an approximately 20% identity with bacterial Oxds. OxdAsp contains a heme prosthetic group bound with the axial H287 in the catalytic pocket. The structure models of OxdAsp with substrates suggest that its catalytic triad is Y138-R141-E192, which is different from the classically bacterial Oxds of His-Arg-Ser/Thr. The catalytic mechanism of OxdAsp was proposed based on the mutagenesis of key residues. The hydroxyl group of the substrate is fixed by E192 to increase its basicity. Y138 acts as a general acid-based catalyst, and its phenolic proton is polarized by the adjacent R141. The protonated Y138 would donate a proton to the hydroxyl group of the substrate and eliminate a water molecule from aldoxime to produce nitrile. The recombinant OxdAsp can efficiently dehydrate citronellal oxime and cinnamaldoxime to citronellyl nitrile and cinnamonitrile in aqueous media, which are applied as fragrance ingredients in the food and cosmetic fields. KEY POINTS: • A novel aldoxime dehydratase from the Aspergillus genus was first characterized as a heme-binding protein. • The catalytic mechanism was predicted based on the molecular interactions of the catalytic pocket with the substrate. • A chemoenzymatic strategy was developed to synthesize nitriles from natural aldehydes with aldoxime as the intermediate.


Assuntos
Bactérias , Prótons , Bactérias/metabolismo , Hidroliases/metabolismo , Nitrilas/metabolismo , Aldeídos
16.
Langmuir ; 39(37): 13028-13037, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37671509

RESUMO

Water scarcity presents a pressing global challenge, necessitating innovative solutions, such as the collection of water from the air using conical structures. However, current research primarily focuses on mist collection rather than on nanoscale clusters of water molecules. Under standard atmospheric conditions, water vapor predominantly exists as imperceptible clusters. Therefore, it is crucial to investigate the interactions between these water molecule clusters and conical structures, particularly regarding whether the conical shape induces Laplace pressure difference on the adhering cluster formations. To gain deeper insights and determine optimal droplet collection structures, we conducted molecular dynamics simulations to investigate interactions between water molecule clusters and conical structures. Our investigations focused on studying the interactions between conical structures and water molecule clusters with varying densities, as well as the impact of surface energies on the collection of water by these conical structures. Notably, our simulations unveiled the significant roles played by van der Waals forces and Laplace pressure in the process of collecting water molecule clusters. Furthermore, our simulations revealed that Janus conical structures, featuring two distinct surface energy regions, played a crucial role in promoting the aggregation of water molecules, resulting in the formation of larger droplets. This aggregation was driven by surface tension gradients, which arise from the contrasting wetting properties in different regions of the Janus structure. As a consequence, under the influence of gravitational forces, these larger droplets could eventually detach from the structure. Through the combined effects of surface tension gradients and gravitational forces, Janus conical structures offer a promising avenue for enhancing the collection efficiency of water from the air. Our research sheds light on the fundamental mechanisms governing water molecule cluster-based water collection and provides valuable insights for the design of more efficient and effective water collection systems.

17.
Funct Plant Biol ; 50(9): 701-711, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37531972

RESUMO

Suaeda salsa is an important salt- and drought-tolerant plant with important ecological restoration roles. However, little is known about its underlying molecular regulatory mechanisms. Therefore, understanding the response mechanisms of plants to salt and drought stress is of great importance. In this study, metabolomics analysis was performed to evaluate the effects of salt and drought stress on S. salsa . The experiment consisted of three treatments: (1) control (CK); (2) salt stress (Ps); and (3) drought stress (Pd). The results showed that compared with the control group, S. salsa showed significant differences in phenotypes under salt and drought stress conditions. First, a total of 207 and 292 differential metabolites were identified in the Ps/CK and Pd/CK groups, respectively. Second, some soluble sugars and amino acids, such as raffinose, maltopentoses, D -altro-beptulose, D -proline, valine-proline, proline, tryptophan and glycine-L -leucine, showed increased activity under salt and drought stress conditions, suggesting that these metabolites may be responsible for salt and drought resistance in S. salsa . Third, the flavonoid biosynthetic and phenylalanine metabolic pathways were significantly enriched under both salt and drought stress conditions, indicating that these two metabolic pathways play important roles in salt and drought stress resistance in S. salsa . The findings of this study provide new insights into the salt and drought tolerance mechanisms of S. salsa .


Assuntos
Chenopodiaceae , Secas , Metabolômica/métodos , Chenopodiaceae/genética , Chenopodiaceae/metabolismo , Estresse Salino , Redes e Vias Metabólicas
18.
Funct Plant Biol ; 50(10): 765-776, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37562446

RESUMO

Drought and salinity are the main factors limiting agricultural production. Improving crop resistance to relieve land stress is a major challenge in agriculture. The salt-tolerant species Suaeda salsa is a typical indicator of saline soil. It has a strong drought tolerance and can be used as a model plant to study salt and drought tolerance in plants. In this study, transcriptome sequencing and bioinformatic analysis were performed to study gene expression changes in S. salsa under salt and drought stresses, and to screen out differentially expressed genes. The genetic changes were most abundant in cellular processes, metabolic processes, ion binding, signalling, post-translational modifications, protein conversion, and molecular chaperones, suggesting that the above methods may play a significant role in the response of S. salsa to external salt and drought stress. Enrichment analysis showed that carbohydrate metabolic processes, oxidoreductase activity, transmembrane transport, kinase activity, cellular protein modification processes, and ion-binding pathways are involved in the stress response of S. salsa .

19.
Front Oncol ; 13: 1205163, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37388227

RESUMO

Purpose: To establish and validate a machine learning based radiomics model for detection of perineural invasion (PNI) in gastric cancer (GC). Methods: This retrospective study included a total of 955 patients with GC selected from two centers; they were separated into training (n=603), internal testing (n=259), and external testing (n=93) sets. Radiomic features were derived from three phases of contrast-enhanced computed tomography (CECT) scan images. Seven machine learning (ML) algorithms including least absolute shrinkage and selection operator (LASSO), naïve Bayes (NB), k-nearest neighbor (KNN), decision tree (DT), logistic regression (LR), random forest (RF), eXtreme gradient boosting (XGBoost) and support vector machine (SVM) were trained for development of optimal radiomics signature. A combined model was constructed by aggregating the radiomic signatures and important clinicopathological characteristics. The predictive ability of the radiomic model was then assessed with receiver operating characteristic (ROC) and calibration curve analyses in all three sets. Results: The PNI rates for the training, internal testing, and external testing sets were 22.1, 22.8, and 36.6%, respectively. LASSO algorithm was selected for signature establishment. The radiomics signature, consisting of 8 robust features, revealed good discrimination accuracy for the PNI in all three sets (training set: AUC = 0.86; internal testing set: AUC = 0.82; external testing set: AUC = 0.78). The risk of PNI was significantly associated with higher radiomics scores. A combined model that integrated radiomics and T stage demonstrated enhanced accuracy and excellent calibration in all three sets (training set: AUC = 0.89; internal testing set: AUC = 0.84; external testing set: AUC = 0.82). Conclusion: The suggested radiomics model exhibited satisfactory prediction performance for the PNI in GC.

20.
Front Cell Dev Biol ; 11: 1194199, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37333982

RESUMO

Background: Hepatocellular carcinoma (HCC) is among the deadliest cancers worldwide, and advanced HCC is difficult to treat. Identifying specific cell subpopulations in the tumor microenvironment and exploring interactions between the cells and their environment are crucial for understanding the development, prognosis, and treatment of tumors. Methods: In this study, we constructed a tumor ecological landscape of 14 patients with HCC from 43 tumor tissue samples and 14 adjacent control samples. We used bioinformatics analysis to reveal cell subpopulations with potentially specific functions in the tumor microenvironment and to explore the interactions between tumor cells and the tumor microenvironment. Results: Immune cell infiltration was evident in the tumor tissues, and BTG1 + RGS1 + central memory T cells (Tcms) interact with tumor cells through CCL5-SDC4/1 axis. HSPA1B may be associated with remodeling of the tumor ecological niche in HCC. Cancer-associated fibroblasts (CAFs) and macrophages (TAMs) were closely associated with tumor cells. APOC1 + SPP1 + TAM secretes SPP1, which binds to ITGF1 secreted by CAFs to remodel the tumor microenvironment. More interestingly, FAP + CAF interacts with naïve T cells via the CXCL12-CXCR4 axis, which may lead to resistance to immune checkpoint inhibitor therapy. Conclusion: Our study suggests the presence of tumor cells with drug-resistant potential in the HCC microenvironment. Among non-tumor cells, high NDUFA4L2 expression in fibroblasts may promote tumor progression, while high HSPA1B expression in central memory T cells may exert anti-tumor effects. In addition, the CCL5-SDC4/1 interaction between BTG1 + RGS1 + Tcms and tumor cells may promote tumor progression. Focusing on the roles of CAFs and TAMs, which are closely related to tumor cells, in tumors would be beneficial to the progress of systemic therapy research.

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