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1.
Biomed Pharmacother ; 178: 117188, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-39053427

RESUMEN

Multiple sclerosis (MS) is an autoimmune-mediated chronic inflammatory demyelinating disease of the central nervous system (CNS) that poses significant treatment challenges. Currently, it is believed that inflammatory and neuroprotective reactive astrocytes, along with other resident CNS cells and immune cells, contribute to the pathophysiology of MS. In our study, we found that isoliquiritigenin (ILG), a bioactive chalcone compound, significantly reduces the clinical scores of experimental autoimmune encephalomyelitis (EAE) by 44 % (P < 0.05). Additionally, ILG significantly decreases the pathological scores of spinal cord inflammation and demyelination by 61 % and 65 %, respectively (both P < 0.0001). Furthermore, ILG affects the populations of CD4, Th1, Th17, and Treg cells in vivo. More importantly, ILG significantly promotes the activation of astrocytes in EAE (P < 0.0001). Additionally, ILG treatment indirectly inhibits inflammatory reactive astrocytes and promotes neuroprotective reactive astrocytes. It reduces spleen levels of TNFα, IL1α, C1qa, IL1ß, and IL17A by 95 % (P < 0.001), 98 % (P < 0.01), 46 % (P < 0.05), 97 % (P < 0.001), and 60 % (P < 0.001), respectively. It also decreases CNS levels of TNFα, IL1α, C1qa, IL1ß, and IL17A by 53 % (P < 0.05), 88 % (P < 0.05), 64 % (P < 0.01), 57 % (P < 0.05), and 60 % (P < 0.001), respectively. These results indicate that ILG exerts an immunoregulatory effect by inhibiting the secretion of pro-inflammatory cytokines. Consequently, ILG inhibits inflammatory reactive astrocytes, promotes neuroprotective reactive astrocytes, alleviates inflammation and improves EAE. These findings provide a theoretical basis and support for the application of ILG in the prevention and treatment of MS.

2.
World J Gastrointest Oncol ; 16(6): 2271-2283, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38994170

RESUMEN

The morbidity and mortality of gastrointestinal (GI) malignancies are among the highest in the world, posing a serious threat to human health. Because of the insidious onset of the cancer, it is difficult for patients to be diagnosed at an early stage, and it rapidly progresses to an advanced stage, resulting in poor treatment and prognosis. Fusobacterium nucleatum (F. nucleatum) is a gram-negative, spore-free anaerobic bacterium that primarily colonizes the oral cavity and is implicated in the development of colorectal, esophageal, gastric, and pancreatic cancers via various intricate mechanisms. Recent development in novel research suggests that F. nucleatum may function as a biomarker in GI malignancies. Detecting the abundance of F. nucleatum in stool, saliva, and serum samples of patients may aid in the diagnosis, risk assessment, and prognosis monitoring of GI malignancies. This editorial systematically describes the biological roles and mechanisms of F. nucleatum in GI malignancies focusing on the application of F. nucleatum as a biomarker in the diagnosis and prognosis of GI malignancies to promote the clinical translation of F. nucleatum and GI tumors-related research.

3.
Ecol Evol ; 14(7): e11662, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38983700

RESUMEN

Crop wild relatives (CWR) provide a valuable resource for improving crops. They possess desirable traits that confer resilience to various environmental stresses. To fully utilize crop wild relatives in breeding and conservation programs, it is important to understand the genetic basis of their adaptation. Landscape genomics associates environments with genomic variation and allows for examining the genetic basis of adaptation. Our study examined the differences in allele frequency of 15,416 single nucleotide polymorphisms (SNPs) generated through genotyping by sequencing approach among 153 accessions of 15 wild eggplant relatives and two cultivated species from Africa, the principal hotspot of these wild relatives. We also explored the correlation between these variations and the bioclimatic and soil conditions at their collection sites, providing a comprehensive understanding of the genetic signals of environmental adaptation in African wild eggplant. Redundancy analysis (RDA) results showed that the environmental variation explained 6% while the geographical distances among the collection sites explained 15% of the genomic variation in the eggplant wild relative populations when controlling for population structure. Our findings indicate that even though environmental factors are not the main driver of selection in eggplant wild relatives, it is influential in shaping the genomic variation over time. The selected environmental variables and candidate SNPs effectively revealed grouping patterns according to the environmental characteristics of sampling sites. Using four genotype-environment association methods, we detected 396 candidate SNPs (2.5% of the initial SNPs) associated with eight environmental factors. Some of these SNPs signal genes involved in pathways that help adapt to environmental stresses such as drought, heat, cold, salinity, pests, and diseases. These candidate SNPs will be useful for marker-assisted improvement and characterizing the germplasm of this crop for developing climate-resilient eggplant varieties. The study provides a model for applying landscape genomics to other crops' wild relatives.

4.
PLoS One ; 19(7): e0298564, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39008464

RESUMEN

High-quality, chromosome-scale genomes are essential for genomic analyses. Analyses, including 3D genomics, epigenetics, and comparative genomics rely on a high-quality genome assembly, which is often accomplished with the assistance of Hi-C data. Curation of genomes reveal that current Hi-C-assisted scaffolding algorithms either generate ordering and orientation errors or fail to assemble high-quality chromosome-level scaffolds. Here, we offer the software Puzzle Hi-C, which uses Hi-C reads to accurately assign contigs or scaffolds to chromosomes. Puzzle Hi-C uses the triangle region instead of the square region to count interactions in a Hi-C heatmap. This strategy dramatically diminishes scaffolding interference caused by long-range interactions. This software also introduces a dynamic, triangle window strategy during assembly. Initially small, the window expands with interactions to produce more effective clustering. Puzzle Hi-C outperforms available scaffolding tools.


Asunto(s)
Algoritmos , Genómica , Programas Informáticos , Genómica/métodos , Cromosomas/genética , Humanos , Genoma
5.
J Environ Manage ; 366: 121830, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39013316

RESUMEN

The rapid expansion of laver (Porphyra yezoensis) cultivation on lower tidal flats has become integral to the local economy, yet it also raises concerns regarding its potential impact on the morphological evolution due to increasing human activities. This study utilizes integrated near-bed field measurements to assess morphological dynamics and quantify sediment erosion processes, highlighting the significant impact of laver harvest on tidal flat stability. Our results show that erosion and bed coarsening in the cultivated areas experienced a notable intensification immediately after harvest, with net erosion in cultivated areas reaching approximately -38.2 mm during the first tide post-harvest, markedly higher-more than an order of magnitude-compared to adjacent uncultivated areas. The erosion rate notably spiked with the average bed level change rate increasing to -13.8 × 10-4 mm/s, compared to a rate of +0.3 × 10-4 mm/s during the unharvest period. Subsequently, the cultivated areas entered a recovery phase with a deposition amount of +12.5 mm, while the net cumulative erosion thickness throughout the entire observation period was -25.2 mm. The cultivation method, characterized by consistent harvests every 10 days, means that even minor erosion from continuous harvests can escalate into significant degradation. This study suggests that long-term cultivation cycle practices may result in irreversible changes to the depositional environment, potentially jeopardizing the habitat viability and ecological function. Sustainable agricultural strategies, including site selection, infrastructure planning, monitoring environmental changes, ecological assessments and sustainable practices, are recommended to mitigate the negative impacts of cultivation on regional stability and preserve the coastal ecological balance.

6.
Biotechnol J ; 19(7): e2400287, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39014925

RESUMEN

The d-amino acid oxidase (DAAO) is pivotal in obtaining optically pure l-glufosinate (l-PPT) by converting d-glufosinate (d-PPT) to its deamination product. We screened and designed a Rasamsonia emersonii DAAO (ReDAAO), making it more suitable for oxidizing d-PPT. Using Caver 3.0, we delineated three substrate binding pockets and, via alanine scanning, identified nearby key residues. Pinpointing key residues influencing activity, we applied virtual saturation mutagenesis (VSM), and experimentally validated mutants which reduced substrate binding energy. Analysis of positive mutants revealed elongated side-chain prevalence in substrate binding pocket periphery. Although computer-aided approaches can rapidly identify advantageous mutants and guide further design, the mutations obtained in the first round may not be suitable for combination with other advantageous mutations. Therefore, each round of combination requires reasonable iteration. Employing VSM-assisted screening multiple times and after four rounds of combining mutations, we ultimately obtained a mutant, N53V/F57Q/V94R/V242R, resulting in a mutant with a 5097% increase in enzyme activity compared to the wild type. It provides valuable insights into the structural determinants of enzyme activity and introduces a novel rational design procedure.


Asunto(s)
D-Aminoácido Oxidasa , Ingeniería de Proteínas , D-Aminoácido Oxidasa/genética , D-Aminoácido Oxidasa/metabolismo , D-Aminoácido Oxidasa/química , Ingeniería de Proteínas/métodos , Especificidad por Sustrato , Mutagénesis , Mutagénesis Sitio-Dirigida/métodos , Aminobutiratos/metabolismo , Modelos Moleculares , Mutación , Sitios de Unión
7.
Int Breastfeed J ; 19(1): 46, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38956574

RESUMEN

BACKGROUND: Limited research has explored the associations of gestational age (GA) and breastfeeding practices with growth and nutrition in term infants. METHODS: This multicenter cross-sectional study recruited 7299 singleton term infants from well-child visits in Shandong, China, between March 2021 and November 2022. Data on GA, gender, ethnicity, birth weight, parental heights, gestational diabetes and hypertension, age at visit, breastfeeding practices (point-in-time data at visit for infants < 6 months and retrospective data at 6 months for infants ≥ 6 months), complementary foods introduction, infant length and weight, were collected. 7270 infants were included in the analysis after excluding outliers with Z-scores of length (LAZ), weight or weight for length (WLZ) <-4 or > 4. Linear regression models adjused for covariates explored the impact of GA and breastfeeding practices on LAZ and WLZ, while logistic regression models evaluated their effect on the likelihood of moderate and severe stunting (MSS, LAZ<-2), moderate and severe acute malnutrition (MSAM, WLZ<-2) and overweight/obesity (WLZ > 2). Sensitivity analysis was conducted on normal birth weight infants (2.5-4.0 kg). RESULTS: Infants born early-term and exclusively breastfed accounted for 31.1% and 66.4% of the sample, respectively. Early-term birth related to higher WLZ (< 6 months: ß = 0.23, 95% confidence interval (CI): 0.16, 0.29; ≥6 months: ß = 0.12, 95% CI: 0.04, 0.20) and an increased risk of overweight/obesity throughout infancy (< 6 months: OR: 1.41, 95% CI 1.08, 1.84; ≥6 months: OR: 1.35, 95% CI 1.03, 1.79). Before 6 months, early-term birth correlated with lower LAZ (ß=-0.16, 95% CI: -0.21, -0.11) and an increased risk of MSS (OR: 1.01, 95%CI 1.00, 1.02); Compared to exclusive breastfeeding, exclusive formula-feeding and mixed feeding linked to lower WLZ (ß=-0.15, 95%CI -0.30, 0.00 and ß=-0.12, 95%CI -0.19, -0.05, respectively) and increased risks of MSAM (OR: 5.57, 95%CI 1.95, 15.88 and OR: 3.19, 95%CI 1.64, 6.19, respectively). Sensitivity analyses confirmed these findings. CONCLUSIONS: The findings emphasize the health risks of early-term birth and the protective effect of exclusive breastfeeding in singleton term infants, underscoring the avoidance of nonmedically indicated delivery before 39 weeks and promoting exclusive breastfeeding before 6 months.


Asunto(s)
Lactancia Materna , Humanos , Lactancia Materna/estadística & datos numéricos , Estudios Transversales , Femenino , Masculino , Recién Nacido , Lactante , China/epidemiología , Edad Gestacional , Fenómenos Fisiológicos Nutricionales del Lactante , Nacimiento a Término , Estudios Retrospectivos , Adulto , Estado Nutricional
8.
Ren Fail ; 46(2): 2367708, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38973391

RESUMEN

BACKGROUND: Cellular senescence, macrophages infiltration, and vascular smooth muscle cells (VSMCs) osteogenic transdifferentiation participate in the pathophysiology of vascular calcification in chronic kidney disease (CKD). Senescent macrophages are involved in the regulation of inflammation in pathological diseases. In addition, senescent cells spread senescence to neighboring cells via Interferon-induced transmembrane protein3 (IFITM3). However, the role of senescent macrophages and IFITM3 in VSMCs calcification remains unexplored. AIMS: To explore the hypothesis that senescent macrophages contribute to the calcification and senescence of VSMCs via IFITM3. METHODS: Here, the macrophage senescence model was established using Lipopolysaccharides (LPS). The VSMCs were subjected to supernatants from macrophages (MCFS) or LPS-induced macrophages (LPS-MCFS) in the presence or absence of calcifying media (CM). Senescence-associated ß-galactosidase (SA-ß-gal), Alizarin red (AR), immunofluorescent staining, and western blot were used to identify cell senescence and calcification. RESULTS: The expression of IFITM3 was significantly increased in LPS-induced macrophages and the supernatants. The VSMCs transdifferentiated into osteogenic phenotype, expressing higher osteogenic differentiation markers (RUNX2) and lower VSMCs constructive makers (SM22α) when cultured with senescent macrophages supernatants. Also, senescence markers (p16 and p21) in VSMCs were significantly increased by senescent macrophages supernatants treated. However, IFITM3 knockdown inhibited this process. CONCLUSIONS: Our study showed that LPS-induced senescence of macrophages accelerated the calcification of VSMCs via IFITM3. These data provide a new perspective linking VC and aging, which may provide clues for diagnosing and treating accelerated vascular aging in patients with CKD.


Asunto(s)
Senescencia Celular , Lipopolisacáridos , Macrófagos , Proteínas de la Membrana , Músculo Liso Vascular , Proteínas de Unión al ARN , Calcificación Vascular , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patología , Lipopolisacáridos/farmacología , Calcificación Vascular/patología , Calcificación Vascular/metabolismo , Macrófagos/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas de Unión al ARN/metabolismo , Humanos , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patología , Insuficiencia Renal Crónica/metabolismo , Insuficiencia Renal Crónica/patología , Células Cultivadas , Animales , Osteogénesis , Transdiferenciación Celular
9.
ACS Nano ; 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39012271

RESUMEN

The edges of 2D materials have emerged as promising electrochemical catalyst systems, yet their performance still lags behind that of noble metals. Here, we demonstrate the potential of oriented electric fields (OEFs) to enhance the electrochemical activity of 2D materials edges. By atomically engineering the edge of a fluorographene/graphene/MoS2 heterojunction nanoribbon, strong and localized OEFs were realized as confirmed by simulations and spatially resolved spectroscopy. The observed fringing OEF results in an enhancement of the heterogeneous charge transfer rate between the edge and the electrolyte by 2 orders of magnitude according to impedance spectroscopy. Ab initio calculations indicate a field-induced decrease in the reactant adsorption energy as the origin of this improvement. We apply the OEF-enhanced edge reactivity to hydrogen evolution reactions (HER) and observe a significantly enhanced electrochemical performance, as evidenced by a 30% decrease in Tafel slope and a 3-fold enhanced turnover frequency. Our findings demonstrate the potential of OEFs for tailoring the catalytic properties of 2D material edges toward future complex reactions.

10.
Int Immunopharmacol ; 139: 112710, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39029229

RESUMEN

PANoptosis is manifested with simultaneous activation of biomarkers for both pyroptotic, apoptotic and necroptotic signaling via the molecular platform PANoptosome and it is involved in pathologies of various inflammatory diseases including hemophagocytic lymphohistiocytosis (HLH). Scutellarin is a flavonoid isolated from herbal Erigeron breviscapus (Vant.) Hand.-Mazz. and has been shown to possess multiple pharmacological effects, but it is unknown whether scutellarin has any effects on PANoptosis and related inflammatory diseases. In this study, we found that scutellarin inhibited cell death in bone marrow-derived macrophages (BMDMs) and J774A.1 cells treated with TGF-ß-activated kinase 1 (TAK1) inhibitor 5Z-7-oxozeaenol (OXO) plus lipopolysaccharide (LPS), which has been commonly used to induce PANoptosis. Western blotting showed that scutellarin dose-dependently inhibited the activation biomarkers for pyroptotic (Caspase-1p10 and GSDMD-NT), apoptotic (cleaved Casp3/8/9 and GSDME-NT), and necroptotic (phosphorylated MLKL) signaling. The inhibitory effect of scutellarin was unaffected by NLRP3 or Caspase-1 deletion. Interestingly, scutellarin blocked the assembly of PANoptosome that encompasses ASC, RIPK3, Caspase-8 and ZBP1, suggesting its action on upstream signaling. Consistent with this, scutellarin inhibited mitochondrial damage and mitochondrial reactive oxygen species (mtROS) generation in cells treated with OXO+LPS. Further, mito-TEMPO that can scavenge mtROS significantly inhibited OXO+LPS-induced PANoptotic cell death. In line with the in vitro results, scutellarin markedly alleviated systemic inflammation, multiple organ injury, and activation of PANoptotic biomarkers in mice with HLH. Collectively, our data suggest that scutellarin can inhibit PANoptosis by suppressing mitochondrial damage and mtROS generation and thereby mitigating multiple organ injury in mice with inflammatory disorders.

11.
PhytoKeys ; 243: 231-248, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38974888

RESUMEN

Paraphlomisqingyuanensis and P.baiwanensis (Lamiaceae), two new species from the limestone area in Guangdong Province, China, are described. Morphologically, both species belong to P.ser.Subcoriaceae C.Y. Wu & H.W. Li. A close relationship between the two new and P.subcoriacea was revealed by molecular phylogenetic analyses based on ETS and ITS. Further morphological and population genetic evidence indicated that they are distinct species in Paraphlomis. According to the IUCN Red List Categories and Criteria, P.qingyuanensis and P.baiwanensis were assessed as Endangered (EN) and Deficient (DD), respectively.

12.
Am J Surg Pathol ; 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38979928

RESUMEN

Burkitt lymphoma is characterized by high cell turnover and numerous cytoplasmic vacuoles that are demonstrated to be lipid droplets (LDs) decorated by adipophilin. By contrast, cytoplasmic vacuoles are variably observed in diffuse large B-cell lymphoma (DLBCL) and less well characterized. In this study, we first validated in DLBCL that cytoplasmic vacuoles are indeed LDs by Oil-red-O stain, Bodipy fluorescent stain, and electron microscopy. Second, in a cohort of DLBCL patients (n=52) we showed that LDs in effusional lymphoma cells were associated with a poorer prognosis (P=0.029, log-rank test) and higher International Prognostic Index (IPI) score (94% vs. 66%, P=0.026) than those without. Moreover, using adipophilin as a surrogate marker for LDs, we found in another cohort of biopsy specimen (n=85) that expression of adipophilin by lymphoma cells predicted a poorer prognosis (P=0.007, log-rank test) and higher IPI score (63% vs. 30%, P=0.005). In addition, whole exome sequencing of effusional DLBCL cells showed LD-positive DLBCL shared genetic features with the MCD (MYD88 and CD79B mutations) subtype and highlighted OSBPL10 and CUBN as the most frequently mutated genes involved in lipogenesis. Whole transcriptome analysis by comparing effusional DLBCL cells with versus without LDs showed upregulation of EHHADH, SLC1A1, CD96, INPP4B, and RNF183 relevant for lymphoma lipogenesis and upregulation of epithelial-mesenchymal transition and KRAS signaling pathways. Higher expression of EHHADH and CD96 were validated in LD-positive clinical samples and LD-rich cell lines than LD-poor cells along with the known lipogenic gene, FASN. Our findings highlight the roles of LDs and adipophilin expression in DLBCL, suggest that these markers may predict prognosis and show that lipogenic genes may be potential therapeutic targets.

13.
World J Hepatol ; 16(6): 900-911, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38948438

RESUMEN

Achievement of a 'clinical cure' in chronic hepatitis B (CHB) implies sustained virological suppression and immunological control over the infection, which is the ideal treatment goal according to domestic and international CHB management guidelines. Clinical practice has shown encouraging results for specific patient cohorts using tailored treatment regimens. These regimens incorporate either nucleos(t)ide analogs, immunomodulatory agents such as pegylated interferon α, or a strategic combination of both, sequentially or concurrently administered. Despite these advancements in the clinical handling of hepatitis B, achieving a clinical cure remains elusive for a considerable subset of patients due to the number of challenges that preclude the realization of optimal treatment outcomes. These include, but are not limited to, the emergence of antiviral resistance, incomplete immune recovery, and the persistence of covalently closed circular DNA. Moreover, the variance in response to interferon therapy and the lack of definitive biomarkers for treatment cessation also contribute to the complexity of achieving a clinical cure. This article briefly overviews the current research progress and existing issues in pursuing a clinical cure for hepatitis B.

14.
Artículo en Inglés | MEDLINE | ID: mdl-38954294

RESUMEN

PURPOSE: Oocyte maturation defect (OOMD) is a rare cause of in vitro fertilization failure characterized by the production of immature oocytes. Compound heterozygous or homozygous PATL2 mutations have been associated with oocyte arrest at the germinal vesicle (GV), metaphase I (MI), and metaphase II (MII) stages, as well as morphological changes. METHODS: In this study, we recruited three OOMD cases and conducted a comprehensive multiplatform laboratory investigation. RESULTS: Whole exome sequence (WES) revealed four diagnostic variants in PATL2, nonsense mutation c.709C > T (p.R237*) and frameshift mutation c.1486_1487delinsT (p.A496Sfs*4) were novel mutations that have not been reported previously. Furthermore, the pathogenicity of these variants was predicted using in silico analysis, which indicated detrimental effects. Molecular dynamic analysis suggested that the A496S variant disrupted the hydrophobic segment, leading to structural changes that affected the overall protein folding and stability. Additionally, biochemical and molecular experiments were conducted on cells transfected with wild-type (WT) or mutant PATL2 (p.R237* and p.A496Sfs*4) plasmid vectors. CONCLUSIONS: The results demonstrated that PATL2A496Sfs*4 and PATL2R237* had impacts on protein size and expression level. Interestingly, expression levels of specific genes involved in oocyte maturation and early embryonic development were found to be simultaneously deregulated. The findings in our study expand the variation spectrum of the PATL2 gene, provide solid evidence for counseling on future pregnancies in affected families, strongly support the application of in the diagnosis of OOMD, and contribute to the understanding of PATL2 function.

15.
J Agric Food Chem ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38842002

RESUMEN

The nicotinamide phosphoribosyltransferase (NAMPT)-catalyzed substitution reaction plays a pivotal role in the biosynthesis of nucleotide compounds. However, industrial applications are hindered by the low activity of NAMPTs. In this study, a novel dual-channel protein engineering strategy was developed to increase NAMPT activity by enhancing substrate accessibility. The best mutant (CpNAMPTY13G+Y15S+F76P) with a remarkable 5-fold increase in enzyme activity was obtained. By utilizing CpNAMPTY13G+Y15S+F76P as a biocatalyst, the accumulation of ß-nicotinamide mononucleotide reached as high as 19.94 g L-1 within 3 h with an impressive substrate conversion rate of 99.8%. Further analysis revealed that the newly generated substrate channel, formed through crack propagation, facilitated substrate binding and enhanced byproduct tolerance. In addition, three NAMPTs from different sources were designed based on the dual-channel protein engineering strategy, and the corresponding dual-channel mutants with improved enzyme activity were obtained, which proved the effectiveness and practicability of the approach.

16.
Biotechnol Bioeng ; 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38822747

RESUMEN

D-amino acid oxidase (DAAO)-catalyzed selective oxidative deamination is a very promising process for synthesizing l-amino acids including l-phosphinothricin ( l-PPT, a high-efficiency and broad-spectrum herbicide). However, the wild-type DAAO's low activity toward unnatural substrates like d-phosphinothricin ( d-PPT) hampers its application. Herein, a DAAO from Caenorhabditis elegans (CeDAAO) was screened and engineered to improve the catalytic potential on d-PPT. First, we designed a novel growth selection system, taking into account the intricate relationship between the growth of Escherichia coli (E. coli) and the catalytic mechanism of DAAO. The developed system was used for high-throughput screening of gene libraries, resulting in the discovery of a variant (M6) with significantly increased catalytic activity against d-PPT. The variant displays different catalytic properties on substrates with varying hydrophobicity and hydrophilicity. Analysis using Alphafold2 modeling and molecular dynamic simulations showed that the reason for the enhanced activity was the substrate-binding pocket with enlarged size and suitable charge distribution. Further QM/MM calculations revealed that the crucial factor for enhancing activity lies in reducing the initial energy barrier of the reductive half reaction. Finally, a comprehensive binding-model index to predict the enhanced activity of DAAO toward d-PPT, and an enzymatic deracemization approach was developed, enabling the efficient synthesis of l-PPT with remarkable efficiency.

17.
Nanomaterials (Basel) ; 14(11)2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38869597

RESUMEN

Two-dimensional (2D) materials promise advances in electronic devices beyond Moore's scaling law through extended functionality, such as non-monotonic dependence of device parameters on input parameters. However, the robustness and performance of effects like negative differential resistance (NDR) and anti-ambipolar behavior have been limited in scale and robustness by relying on atomic defects and complex heterojunctions. In this paper, we introduce a novel device concept that utilizes the quantum capacitance of junctions between 2D materials and molecular layers. We realized a variable capacitance 2D molecular junction (vc2Dmj) diode through the scalable integration of graphene and single layers of stearic acid. The vc2Dmj exhibits NDR with a substantial peak-to-valley ratio even at room temperature and an active negative resistance region. The origin of this unique behavior was identified through thermoelectric measurements and ab initio calculations to be a hybridization effect between graphene and the molecular layer. The enhancement of device parameters through morphology optimization highlights the potential of our approach toward new functionalities that advance the landscape of future electronics.

18.
ACS Nano ; 18(27): 17622-17629, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38922204

RESUMEN

Engineering atomic-scale defects has become an important strategy for the future application of transition metal dichalcogenide (TMD) materials in next-generation electronic technologies. Thus, providing an atomic understanding of the electron-defect interactions and supporting defect engineering development to improve carrier transport is crucial to future TMDs technologies. In this work, we utilize low-temperature scanning tunneling microscopy/spectroscopy (LT-STM/S) to elicit how distinct types of defects bring forth scattering potential engineering based on intervalley quantum quasiparticle interference (QPI) in TMDs. Furthermore, quantifying the energy-dependent phase variation of the QPI standing wave reveals the detailed electron-defect interaction between the substitution-induced scattering potential and the carrier transport mechanism. By exploring the intrinsic electronic behavior of atomic-level defects to further understand how defects affect carrier transport in low-dimensional semiconductors, we offer potential technological applications that may contribute to the future expansion of TMDs.

19.
Cells ; 13(12)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38920688

RESUMEN

Serine/threonine kinase AKT isoforms play a well-established role in cell metabolism and growth. Most pancreatic adenocarcinomas (PDACs) harbor activation mutations of KRAS, which activates the PI3K/AKT signaling pathway. However, AKT inhibitors are not effective in the treatment of pancreatic cancer. To better understand the role of AKT signaling in mutant-KRAS pancreatic tumors, this study utilized proteolysis-targeting chimeras (PROTACs) and CRISPR-Cas9-genome editing to investigate AKT proteins. The PROTAC down-regulation of AKT proteins markedly slowed the growth of three pancreatic tumor cell lines harboring mutant KRAS. In contrast, the inhibition of AKT kinase activity alone had very little effect on the growth of these cell lines. The concurrent genetic deletion of all AKT isoforms (AKT1, AKT2, and AKT3) in the KPC (KrasG12D; Trp53R172H; Pdx1-Cre) pancreatic cancer cell line also dramatically slowed its growth in vitro and when orthotopically implanted in syngeneic mice. Surprisingly, insulin-like growth factor-1 (IGF-1), but not epidermal growth factor (EGF), restored KPC cell growth in serum-deprived conditions, and the IGF-1 growth stimulation effect was AKT-dependent. The RNA-seq analysis of AKT1/2/3-deficient KPC cells suggested that reduced cholesterol synthesis may be responsible for the decreased response to IGF-1 stimulation. These results indicate that the presence of all three AKT isoforms supports pancreatic tumor cell growth, and the pharmacological degradation of AKT proteins may be more effective than AKT catalytic inhibitors for treating pancreatic cancer.


Asunto(s)
Regulación hacia Abajo , Mutación , Neoplasias Pancreáticas , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas p21(ras) , Proteínas Proto-Oncogénicas c-akt/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/tratamiento farmacológico , Animales , Línea Celular Tumoral , Ratones , Humanos , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/genética , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Mutación/genética , Proliferación Celular/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 321: 124704, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38936208

RESUMEN

The thiophene- and pyrrole-fused heterocyclic compounds have garnered significant interest for their distinctive electron-rich characteristics and notable optoelectronic properties. However, the construction of high-performance systems within this class is of great challenge. Herein, we develop a series of novel dithieno[3,2-b:2',3'-d] pyrrole (DTP) and tetrathieno[3,2-b:2',3'-d] pyrrole (TTP) bridged arylamine compounds (DTP-C4, DTP-C12, DTP-C4-Fc, TTP-C4-OMe, TTP-C4, and TTP-C12) with varying carbon chain lengths. The pertinent experimental results reveal that this series of compounds undergo completely reversible multistep redox processes. Notably, TTP-bridged compounds TTP-C4 and TTP-C12 exhibit impressive multistep near-infrared (NIR) absorption alterations with notable color changes and electroluminescent behaviors, which are mainly attributed to the charge transfer transitions from terminal arylamine units to central bridges, as supported by theoretical calculations. Additionally, compound DTP-C4 demonstrates the ability to visually identify gram-positive and gram-negative bacteria. Therefore, this work suggests the promising electroresponsive nature of compounds TTP-C4 and TTP-C12, positioning them as excellent materials for various applications. It also provides a facile approach to constructing high-performance multifunctional luminescent materials, particularly those with strong and long-wavelength NIR absorption capabilities.

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