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1.
Biotechnol J ; 19(4): e2300740, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38581087

RESUMO

ß-Phenylethanol (2-PE), as an important flavor component in wine, is widely used in the fields of flavor chemistry and food health. 2-PE can be sustainably produced through Saccharomyces cerevisiae. Although significant progress has been made in obtaining high-yield strains, as well as improving the synthesis pathways of 2-PE, there still lies a gap between these two fields to unpin. In this study, the macroscopic metabolic characteristics of high-yield and low-yield 2-PE strains were systematically compared and analyzed. The results indicated that the production potential of the high-yield strain might be contributed to the enhancement of respiratory metabolism and the high tolerance to 2-PE. Furthermore, this hypothesis was confirmed through comparative genomics. Meanwhile, transcriptome analysis at key specific growth rates revealed that the collective upregulation of mitochondrial functional gene clusters plays a more prominent role in the production process of 2-PE. Finally, findings from untargeted metabolomics suggested that by enhancing respiratory metabolism and reducing the Crabtree effect, the accumulation of metabolites resisting high 2-PE stress was observed, such as intracellular amino acids and purines. Hence, this strategy provided a richer supply of precursors and cofactors, effectively promoting the synthesis of 2-PE. In short, this study provides a bridge for studying the metabolic mechanism of high-yield 2-PE strains with the subsequent targeted strengthening of relevant synthetic pathways. It also provides insights for the synthesis of nonalcoholic products in S. cerevisiae.


Assuntos
Álcool Feniletílico , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Álcool Feniletílico/metabolismo , Multiômica , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Vias Biossintéticas , Fermentação
2.
Pharm Stat ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317370

RESUMO

The Bayesian logistic regression method (BLRM) is a widely adopted and flexible design for finding the maximum tolerated dose in oncology phase I studies. However, the BLRM design has been criticized in the literature for being overly conservative due to the use of the overdose control rule. Recently, a discussion paper titled "Improving the performance of Bayesian logistic regression model with overall control in oncology dose-finding studies" in Statistics in Medicine has proposed an overall control rule to address the "excessive conservativeness" of the standard BLRM design. In this short communication, we discuss the relative conservativeness of the standard BLRM design and also suggest a dose-switching rule to further enhance its performance.

3.
Commun Chem ; 7(1): 45, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418525

RESUMO

The theories for substrate recognition in enzyme catalysis have evolved from lock-key to induced fit, then conformational selection, and conformational selection followed by induced fit. However, the prevalence and consensus of these theories require further examination. Here we use cryogenic electron microscopy and African swine fever virus type 2 topoisomerase (AsfvTop2) to demonstrate substrate binding theories in a joint and ordered manner: catalytic selection by the enzyme, conformational selection by the substrates, then induced fit. The apo-AsfvTop2 pre-exists in six conformers that comply with the two-gate mechanism directing DNA passage and release in the Top2 catalytic cycle. The structures of AsfvTop2-DNA-inhibitor complexes show that substantial induced-fit changes occur locally from the closed apo-conformer that however is too far-fetched for the open apo-conformer. Furthermore, the ATPase domain of AsfvTop2 in the MgAMP-PNP-bound crystal structures coexist in reduced and oxidized forms involving a disulfide bond, which can regulate the AsfvTop2 function.

4.
Nat Commun ; 14(1): 8009, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38049400

RESUMO

Phycobilisomes (PBS) are antenna megacomplexes that transfer energy to photosystems II and I in thylakoids. PBS likely evolved from a basic, inefficient form into the predominant hemidiscoidal shape with radiating peripheral rods. However, it has been challenging to test this hypothesis because ancestral species are generally inaccessible. Here we use spectroscopy and cryo-electron microscopy to reveal a structure of a "paddle-shaped" PBS from a thylakoid-free cyanobacterium that likely retains ancestral traits. This PBS lacks rods and specialized ApcD and ApcF subunits, indicating relict characteristics. Other features include linkers connecting two chains of five phycocyanin hexamers (CpcN) and two core subdomains (ApcH), resulting in a paddle-shaped configuration. Energy transfer calculations demonstrate that chains are less efficient than rods. These features may nevertheless have increased light absorption by elongating PBS before multilayered thylakoids with hemidiscoidal PBS evolved. Our results provide insights into the evolution and diversification of light-harvesting strategies before the origin of thylakoids.


Assuntos
Cianobactérias , Tilacoides , Tilacoides/metabolismo , Ficobilissomas/metabolismo , Microscopia Crioeletrônica , Complexo de Proteína do Fotossistema I/metabolismo , Proteínas de Bactérias/metabolismo , Cianobactérias/metabolismo
6.
Science ; 382(6674): eadd7795, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-38033054

RESUMO

Photolyases, a ubiquitous class of flavoproteins, use blue light to repair DNA photolesions. In this work, we determined the structural mechanism of the photolyase-catalyzed repair of a cyclobutane pyrimidine dimer (CPD) lesion using time-resolved serial femtosecond crystallography (TR-SFX). We obtained 18 snapshots that show time-dependent changes in four reaction loci. We used these results to create a movie that depicts the repair of CPD lesions in the picosecond-to-nanosecond range, followed by the recovery of the enzymatic moieties involved in catalysis, completing the formation of the fully reduced enzyme-product complex at 500 nanoseconds. Finally, back-flip intermediates of the thymine bases to reanneal the DNA were captured at 25 to 200 microseconds. Our data cover the complete molecular mechanism of a photolyase and, importantly, its chemistry and enzymatic catalysis at work across a wide timescale and at atomic resolution.


Assuntos
Proteínas Arqueais , Reparo do DNA , Desoxirribodipirimidina Fotoliase , Methanosarcina , Dímeros de Pirimidina , Proteínas Arqueais/química , Catálise , Cristalografia/métodos , Desoxirribodipirimidina Fotoliase/química , DNA/química , DNA/efeitos da radiação , Methanosarcina/enzimologia , Conformação Proteica , Dímeros de Pirimidina/química , Raios Ultravioleta
7.
Structure ; 31(12): 1567-1577.e5, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-37794594

RESUMO

The structure determination of protein tyrosine phosphatase (PTP): phospho-protein complexes, which is essential to understand how specificity is achieved at the amino acid level, remains a significant challenge for protein crystallography and cryoEM due to the transient nature of binding interactions. Using rPTPεD1 and phospho-SrcKD as a model system, we have established an integrative workflow to address this problem, by means of which we generate a protein:phospho-protein complex model using predetermined protein structures, SAXS and pTyr-tailored MD simulations. Our model reveals transient protein-protein interactions between rPTPεD1 and phospho-SrcKD and is supported by three independent experimental validations. Measurements of the association rate between rPTPεD1 and phospho-SrcKD showed that mutations on the rPTPεD1: SrcKD complex interface disrupts these transient interactions, resulting in a reduction in protein-protein association rate and, eventually, phosphatase activity. This integrative approach is applicable to other PTP: phospho-protein complexes and the characterization of transient protein-protein interface interactions.


Assuntos
Proteínas , Espalhamento a Baixo Ângulo , Difração de Raios X , Fosforilação
9.
Nat Metab ; 5(7): 1111-1126, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37349485

RESUMO

Regulation of CO2 fixation in cyanobacteria is important both for the organism and global carbon balance. Here we show that phosphoketolase in Synechococcus elongatus PCC7942 (SeXPK) possesses a distinct ATP-sensing mechanism, where a drop in ATP level allows SeXPK to divert precursors of the RuBisCO substrate away from the Calvin-Benson-Bassham cycle. Deleting the SeXPK gene increased CO2 fixation particularly during light-dark transitions. In high-density cultures, the Δxpk strain showed a 60% increase in carbon fixation and unexpectedly resulted in sucrose secretion without any pathway engineering. Using cryo-EM analysis, we discovered that these functions were enabled by a unique allosteric regulatory site involving two subunits jointly binding two ATP, which constantly suppresses the activity of SeXPK until the ATP level drops. This magnesium-independent ATP allosteric site is present in many species across all three domains of life, where it may also play important regulatory functions.


Assuntos
Dióxido de Carbono , Fotossíntese , Dióxido de Carbono/metabolismo , Fotossíntese/fisiologia , Ciclo do Carbono , Trifosfato de Adenosina/metabolismo
10.
J Colloid Interface Sci ; 642: 283-291, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37004262

RESUMO

Covalent organic frameworks (COFs) are excellent candidates for rationally designed metal-coordinated catalysts due to their porous structures and adjustable organic building blocks. In this work, a two-dimensional (2D) COF with novel fxt topology was synthesized. The newly devised COF had been fully characterized by a range of spectroscopic and microscopic techniques. The COF was further metallized by the gold species to form a heterogeneous catalyst that enabled the one-pot synthesis of flavone and its derivatives. The Au@COF catalyst showed high catalytic activity and good recyclability. This work demonstrates the great potential of metallized COFs with unique well-defined pores in organic catalysis.

11.
ACS Appl Mater Interfaces ; 15(13): 16631-16639, 2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-36943938

RESUMO

In order to selectively oxidize benzyl alcohol, a novel noble metal catalyst based on polymer ionic liquids with a core-shell structure was created. First, polymer ionic liquid microspheres (PILMs) were prepared by free radical polymerization. Second, the in situ adsorption of Au nanoparticles on the surface of PILMs was accomplished, thanks to the strong electrostatic interaction between N atoms and metal ions on the diazole ring of PILMs. Additionally, the introduction of Al(OH)3 prevented the aggregation of Au nanoparticles and promoted the catalytic reaction. Finally, the PILM/Au/Al(OH)3 catalyst with a core-shell structure was formed. The effectiveness of the PILM/Au/Al(OH)3 catalyst was assessed by varying the catalyst's type, quantity, amount of Au, amount of H2O2, temperature, and reaction time. After five cycles of experiments, the catalyst was effective and reusable. In addition, the potential catalytic mechanism of the catalyst in the oxidation of benzyl alcohol was proposed.

12.
Sci Rep ; 13(1): 4061, 2023 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-36906711

RESUMO

The study aimed to determine the resilience of multi-ethnic, multi-cultural adolescent students in cosmopolitan Singapore, their coping abilities, and the impact on their social and physical activities during the COVID-19 pandemic and its association with their resilience. A total of 582 adolescents in post-secondary education institutes completed an online survey from June to November 2021. The survey assessed their sociodemographic status, resilience level using the Brief Resilience Scale (BRS) and Hardy-Gill Resilience Scale (HGRS), the impact of the COVID-19 pandemic on their daily activities, life settings, social life, social interactions, and coping ability in these aspects of life. Poor ability to cope with school life (adjusted beta = - 0.163, 95% CI - 1.928 to 0.639, p < 0.001), staying home (adjusted beta = - 0.108, 95% CI = - 1.611 to - 0.126, p = 0.022), sports (adjusted beta = - 0.116, 95% CI - 1.691 to - 0.197, p = 0.013) and friends (adjusted beta = - 0.143, 95% CI - 1.904 to - 0.363, p = 0.004) were associated with statistically significant low resilience level measured with HGRS. About half and a third of the participants reported normal and low resilience, respectively, based on BRS (59.6%/32.7%) and HGRS (49.0%/29.0%) scores. Adolescents of Chinese ethnicity and low socioeconomic status had comparatively lower resilience scores. Approximately half of the adolescents in this study had normal resilience despite the COVID-19 pandemic. Adolescents with lower resilience tended to have lower coping abilities. The study did not compare changes in the social life and coping behaviour of the adolescents due to COVID-19, as data on these aspects prior to the pandemic was unavailable.


Assuntos
COVID-19 , Humanos , Adolescente , Pandemias , Renda , Baixo Nível Socioeconômico , Adaptação Psicológica
13.
Front Oncol ; 12: 951560, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36353548

RESUMO

Background: Perineural invasion (PNI), a form of local invasion defined as the ability of cancer cells to invade in, around, and through nerves, has a negative prognostic impact in oral cavity squamous cell carcinoma (OCSCC). Unfortunately, the diagnosis of PNI suffers from a significant degree of intra- and interobserver variability. The aim of this pilot study was to develop a deep learning-based human-enhanced tool, termed domain knowledge enhanced yield (Domain-KEY) algorithm, for identifying PNI in digital slides. Methods: Hematoxylin and eosin (H&E)-stained whole-slide images (WSIs, n = 85) were obtained from 80 patients with OCSCC. The model structure consisted of two parts to simulate human decision-making skills in diagnostic pathology. To this aim, two semantic segmentation models were constructed (i.e., identification of nerve fibers followed by the diagnosis of PNI). The inferred results were subsequently subjected to post-processing of generated decision rules for diagnostic labeling. Ten H&E-stained WSIs not previously used in the study were read and labeled by the Domain-KEY algorithm. Thereafter, labeling correctness was visually inspected by two independent pathologists. Results: The Domain-KEY algorithm was found to outperform the ResnetV2_50 classifier for the detection of PNI (diagnostic accuracy: 89.01% and 61.94%, respectively). On analyzing WSIs, the algorithm achieved a mean diagnostic accuracy as high as 97.50% versus traditional pathology. The observed accuracy in a validation dataset of 25 WSIs obtained from seven patients with oropharyngeal (cancer of the tongue base, n = 1; tonsil cancer, n = 1; soft palate cancer, n = 1) and hypopharyngeal (cancer of posterior wall, n = 2; pyriform sinus cancer, n = 2) malignancies was 96%. Notably, the algorithm was successfully applied in the analysis of WSIs to shorten the time required to reach a diagnosis. The addition of the hybrid intelligence model decreased the mean time required to reach a diagnosis by 15.0% and 23.7% for the first and second pathologists, respectively. On analyzing digital slides, the tool was effective in supporting human diagnostic thinking. Conclusions: The Domain-KEY algorithm successfully mimicked human decision-making skills and supported expert pathologists in the routine diagnosis of PNI.

14.
Microb Cell Fact ; 21(1): 238, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36376878

RESUMO

BACKGROUND: Our recent multi-omics analyses of glucoamylase biosynthesis in Aspergillus niger (A. niger) suggested that lipid catabolism was significantly up-regulated during high-yield period under oxygen limitation. Since the catabolism of fatty acids can provide energy compounds such as ATP and important precursors such as acetyl-CoA, we speculated that enhancement of this pathway might be beneficial to glucoamylase overproduction. RESULTS: Based on previous transcriptome data, we selected and individually overexpressed five candidate genes involved in fatty acid degradation under the control of the Tet-on gene switch in A. niger. Overexpression of the fadE, fadA and cyp genes increased the final specific enzyme activity and total secreted protein on shake flask by 21.3 ~ 31.3% and 16.0 ~ 24.2%, respectively. And a better inducible effect by doxycycline was obtained from early logarithmic growth phase (18 h) than stationary phase (42 h). Similar with flask-level results, the glucoamylase content and total extracellular protein in engineered strains OE-fadE (overexpressing fadE) and OE-fadA (overexpressing fadA) on maltose-limited chemostat cultivation were improved by 31.2 ~ 34.1% and 35.1 ~ 38.8% compared to parental strain B36. Meanwhile, intracellular free fatty acids were correspondingly decreased by 41.6 ~ 44.6%. The metabolomic analysis demonstrated intracellular amino acids pools increased 24.86% and 18.49% in two engineered strains OE-fadE and OE-fadA compared to B36. Flux simulation revealed that increased ATP, acetyl-CoA and NADH was supplied into TCA cycle to improve amino acids synthesis for glucoamylase overproduction. CONCLUSION: This study suggested for the first time that glucoamylase production was significantly improved in A. niger by overexpression of genes fadE and fadA involved in fatty acids degradation pathway. Harnessing the intracellular fatty acids could be a strategy to improve enzyme production in Aspergillus niger cell factory.


Assuntos
Aspergillus niger , Glucana 1,4-alfa-Glucosidase , Glucana 1,4-alfa-Glucosidase/metabolismo , Aspergillus niger/metabolismo , Acetilcoenzima A/metabolismo , Aminoácidos/metabolismo , Ácidos Graxos/metabolismo , Trifosfato de Adenosina/metabolismo
15.
J Clin Neurosci ; 101: 37-46, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35526362

RESUMO

PURPOSE: Solitary type primary intracranial malignant melanoma (PIMM) is extremely rare but fatal. The optimal treatment algorithm according to clinical relevance of symptoms and outcomes is unclear. This series emphasized the prognostic factors of solitary PIMM and established the treatment algorithm for this rare disease. METHODS: Patients with solitary PIMMs were pathologically verified and treated with neurosurgical tumor resection. All solitary PIMMs recruited at our institute received multidisciplinary team care. We analyzed the clinical findings and prognostic factors. RESULTS: The study cohort included 10 patients. PIMMs in solitary type impacted middle-aged populations with male predominance in Taiwan. Most patients (80%) presented a single tumor initially. Six patients had progressed to multiplicity after the initial treatment. Rates of tumor bleeding and leptomeningeal metastasis seeding (LS) are high in solitary PIMMs. Patients who had gross-total resection (GTR) had better survival than those who had incomplete resection, with median overall survival (OS) rates of 170.4 months vs. 5.23 months (p = 0.004). Multiplicity, eloquent area involvement, initial tumor bleeding, LS, hydrocephalus, and Karnofsky Performance Score < 80 at diagnosis were associated with negative outcomes in progression-free survival and OS. Adjuvant radiotherapy for patients who had LS and for those who cannot undergo grossly total tumor removal resulted in a good outcome. CONCLUSIONS: GTR demonstrated better outcomes for solitary PIMM. For recurrent tumors, aggressively repeated surgical resection remained beneficial for selected cases. Adjuvant radiotherapy was a treatment option for LS following operation. We proposed a possible treatment algorithm for solitary PIMM.


Assuntos
Neoplasias Encefálicas , Melanoma , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/cirurgia , Feminino , Humanos , Avaliação de Estado de Karnofsky , Masculino , Melanoma/cirurgia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Intervalo Livre de Progressão , Estudos Retrospectivos , Resultado do Tratamento
16.
Nat Chem ; 14(6): 677-685, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35393554

RESUMO

Flavin coenzymes are universally found in biological redox reactions. DNA photolyases, with their flavin chromophore (FAD), utilize blue light for DNA repair and photoreduction. The latter process involves two single-electron transfers to FAD with an intermittent protonation step to prime the enzyme active for DNA repair. Here we use time-resolved serial femtosecond X-ray crystallography to describe how light-driven electron transfers trigger subsequent nanosecond-to-microsecond entanglement between FAD and its Asn/Arg-Asp redox sensor triad. We found that this key feature within the photolyase-cryptochrome family regulates FAD re-hybridization and protonation. After first electron transfer, the FAD•- isoalloxazine ring twists strongly when the arginine closes in to stabilize the negative charge. Subsequent breakage of the arginine-aspartate salt bridge allows proton transfer from arginine to FAD•-. Our molecular videos demonstrate how the protein environment of redox cofactors organizes multiple electron/proton transfer events in an ordered fashion, which could be applicable to other redox systems such as photosynthesis.


Assuntos
Desoxirribodipirimidina Fotoliase , Prótons , Arginina/metabolismo , Cristalografia , Desoxirribodipirimidina Fotoliase/química , Desoxirribodipirimidina Fotoliase/genética , Desoxirribodipirimidina Fotoliase/metabolismo , Transporte de Elétrons , Elétrons , Flavina-Adenina Dinucleotídeo/química , Flavina-Adenina Dinucleotídeo/metabolismo , Flavinas , Oxirredução
17.
J Cachexia Sarcopenia Muscle ; 13(2): 1314-1328, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35170238

RESUMO

BACKGROUND: Interferon-induced protein with tetratricopeptide repeat 2 (IFIT2) is a reported metastasis suppressor in oral squamous cell carcinoma (OSCC). Metastases and cachexia may coexist. The effect of cancer metastasis on cancer cachexia is largely unknown. We aimed to address this gap in knowledge by characterizing the cachectic phenotype of an IFIT2-depleted metastatic OSCC mouse model. METHODS: Genetically engineered and xenograft tumour models were used to explore the effect of IFIT2-depleted metastatic OSCC on cancer cachexia. Muscle and organ weight changes, tumour burden, inflammatory cytokine profiles, body composition, food intake, serum albumin and C-reactive protein (CRP) levels, and survival were assessed. The activation of the IL6/p38 pathway in atrophied muscle was measured. RESULTS: IFIT2-depleted metastatic tumours caused marked body weight loss (-18.2% vs. initial body weight, P < 0.001) and a poor survival rate (P < 0.01). Skeletal muscles were markedly smaller in IFIT2-depleted metastatic tumour-bearing mice (quadriceps: -28.7%, gastrocnemius: -29.4%, and tibialis: -24.3%, all P < 0.001). Tumour-derived circulating granulocyte-macrophage colony-stimulating factor (+772.2-fold, P < 0.05), GROα (+1283.7-fold, P < 0.05), IL6 (+245.8-fold, P < 0.001), IL8 (+616.9-fold, P < 0.001), IL18 (+24-fold, P < 0.05), IP10 (+18.8-fold, P < 0.001), CCL2 (+439.2-fold, P < 0.001), CCL22 (+9.1-fold, P < 0.01) and tumour necrosis factor α (+196.8-fold, P < 0.05) were elevated in IFIT2-depleted metastatic tumour-bearing mice. Murine granulocyte colony-stimulating factor (+61.4-fold, P < 0.001) and IL6 (+110.9-fold, P < 0.01) levels were significantly increased in IFIT2-depleted metastatic tumour-bearing mice. Serum CRP level (+82.1%, P < 0.05) was significantly increased in cachectic shIFIT2 mice. Serum albumin level (-26.7%, P < 0.01) was significantly decreased in cachectic shIFIT2 mice. An assessment of body composition revealed decreased fat (-81%, P < 0.001) and lean tissue (-21.7%, P < 0.01), which was consistent with the reduced food intake (-19.3%, P < 0.05). Muscle loss was accompanied by a smaller muscle cross-sectional area (-23.3%, P < 0.05). Muscle atrophy of cachectic IFIT2-depleted metastatic tumour-bearing mice (i.v.-shIFIT2 group) was associated with elevated IL6 (+2.7-fold, P < 0.05), phospho-p38 (+2.8-fold, P < 0.05), and atrogin-1 levels (+2.3-fold, P < 0.05) in the skeletal muscle. Neutralization of IL6 rescued shIFIT2 conditioned medium-induced myotube atrophy (+24.6%, P < 0.01). CONCLUSIONS: Our results suggest that the development of shIFIT2 metastatic OSCC lesions promotes IL6 production and is accompanied by the loss of fat and lean tissue, anorexia, and muscle atrophy. This model is appropriate for the study of OSCC cachexia, especially in linking metastasis with cachexia.


Assuntos
Proteínas Reguladoras de Apoptose , Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Proteínas de Ligação a RNA , Animais , Proteínas Reguladoras de Apoptose/genética , Caquexia/patologia , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/complicações , Humanos , Camundongos , Neoplasias Bucais/complicações , Neoplasias Bucais/patologia , Atrofia Muscular/patologia , Proteínas de Ligação a RNA/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/complicações
18.
J Colloid Interface Sci ; 608(Pt 1): 809-819, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785458

RESUMO

Controlling the spatial confinement effect and highly dispersed Pd nanoparticles (NPs) can help to improve applicability in catalysis, energy conversion, and separation. However, the nonspatial confinement effect, agglomeration of Pd NPs of catalyst and harsh reaction conditions have become the urgent problems to be solved in Suzuki-Miyaura cross-coupling reaction. Herein, we report the first application of a new MOFs@COFs by using core with metal organic frameworks (MOFs) NH2-MIL-101(Fe) and shell with covalent organic frameworks (COFs) for loading Pd NPs. The quickly formation of a transition state, the highly dispersed Pd NPs and the advancedly spatial confinement effect were achieved by coupling Fe base synergistic active components, electron-oriented anchoring with controlling pore scale, respectively. Most notably, as a proof-of-concept application, the high catalytic activity of NH2-MIL-101(Fe)@Pd@COFs(3 + 3) in catalysis is elucidated for Suzuki-Miyaura coupling reaction by the broad scope of the reactants and the preeminent yields of the products, together with excellent stability and recoverability. With this strategy, the mechanism of Suzuki-Miyaura coupling reaction was verified by examining the catalytic activity. We hope that our approach can further facilitate the study of the design and use of functional MOFs@Pd@COFs materials.

19.
Pathol Res Pract ; 223: 153474, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33993060

RESUMO

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity with poor prognosis. The dysregulation of Notch signaling pathway has been implicated in the OSCC tumorigenesis. However, the clinical implication of NOTCH1 mutation status in OSCC remains unelucidated. We extracted the NOTCH1 gene mutations from a whole exome sequencing dataset of 168 frozen OSCC tumor specimens and validated these NOTCH1 gene mutations by Sanger sequencing. We also assessed these NOTCH1 gene mutations and its pathological significance in our OSCC tumor tissues using immunohistochemistry. Univariate and multivariate analyses were also used to determine whether the association between NOTCH1 mutation status and prognostic factors was independent of other parameters. In this study, we have identified 44 (26.19 %) NOTCH1 gene mutations from a whole-exome sequencing of 168 OSCC formalin-fixed, paraffin-embedded (FFPE) tissue specimen. These mutations distributed in different NOTCH1 function domains, including the EGF-like repeats region, negative regulatory region, and Ankyrin repeats region. The immunohistochemical staining analysis revealed that NOTCH1 expression was increased in oral cancer tissues. In addition, of the 43 OSCC tumors with NOTCH1 mutations, we observed that the majority were negative for NOTCH1 intracellular domain 1 (NICD1) staining (76.74 %), and 10 tumors were positive for NICD1 staining (23.26 %). In conclusion, our study suggested that NOTCH1 expression is associated with the progression of OSCC. We also demonstrated that presence of a mutated NOTCH1 gene will help prognostic stratification in OSCC when combined with other clinicopathologic parameters.


Assuntos
Biomarcadores Tumorais/genética , Neoplasias Bucais/genética , Mutação , Receptor Notch1/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Análise Mutacional de DNA , Bases de Dados Genéticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Valor Preditivo dos Testes , Prognóstico , Receptor Notch1/metabolismo , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Sequenciamento do Exoma
20.
Int J Mol Sci ; 22(7)2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33917452

RESUMO

Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas. Web-based open megadata minings revealed that FN was mainly mutated in the cBio Cancer Genomic Portal but dominantly overexpressed in the ONCOMINE (a cancer microarray database and integrated data-mining platform) in distinct tumor types. Furthermore, numerous different cancer patients with high FN indeed exhibited a poor prognosis in the PrognoScan mining, indicating that FN involves in tumor malignancy. To investigate further the significance of FN expression in glioma progression, tumor specimens from five malignant gliomas with recurrences that received at least two surgeries were enrolled and examined. The immunohistochemical staining showed that FN expression indeed determined the distinct progressions of malignant gliomas. Furthermore, the expression of vimentin (VIM), a mesenchymal protein that is strongly expressed in malignant cancers, was similar to the FN pattern. Moreover, the level of epithelial-mesenchymal transition (EMT) inducer transforming growth factor-beta (TGF-ß) was almost recapitulated with the FN expression. Together, this study identifies a protein FN that can be used to diagnose GBM from low-grade astrocytoma; moreover, its expression functionally determines the malignant glioma progressions via TGF-ß-induced EMT pathway.


Assuntos
Neoplasias Encefálicas/metabolismo , Fibronectinas/biossíntese , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Proteínas de Neoplasias/biossíntese , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Adulto , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Bases de Dados de Ácidos Nucleicos , Feminino , Fibronectinas/genética , Glioblastoma/diagnóstico , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Prognóstico , Fator de Crescimento Transformador beta/genética
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