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Deep-sea mussels, one of the dominant species in most deep-sea ecosystems, have long been used as model organisms to investigate the adaptations and symbiotic relationships of deep-sea macrofauna under laboratory conditions due to their ability to survive under atmospheric pressure. However, the impact of additional abiotic conditions beyond pressure, such as temperature and light, on their physiological characteristics remains unknown. In this study, deep-sea mussels (Gigantidas platifrons) from cold seep of the South China Sea, along with nearshore mussels (Mytilus coruscus) from the East China Sea, were reared in unfavorable abiotic conditions for up to 8 days. Integrated biochemical indexes including antioxidant defense, immune ability and energy metabolism were investigated in the gill and digestive gland, while cytotoxicity was determined in hemocytes of both types of mussels. The results revealed mild bio-responses in two types of mussels in the laboratory, represented by the effective antioxidant defense with constant total antioxidant capability level and malondialdehyde content. There were also disparate adaptations in deep-sea and nearshore mussels. In deep-sea mussels, significantly increased immune response and energy reservation were observed in gills, together with the elevated cytotoxicity in hemocytes, implying the more severe biological adaptation was required, mainly due to the symbiotic bacteria loss under laboratory conditions. On the contrary, insignificant biological responses were exhibited in nearshore mussels except for the increased energy consumption, indicating the trade-off strategy to use more energy to deal with potential stress. Overall, this comparative study highlights the basal bio-responses of deep-sea and nearshore mussels out of their native environments, providing evidence that short-term culture of both mussels under easily achievable laboratory conditions would not dramatically alter their biological status. This finding will assist in broadening the application of deep-sea mussels as model organism in future research regardless of the specialized research equipment.
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Bivalves , Animais , Bivalves/fisiologia , Adaptação Fisiológica , Brânquias/metabolismo , Antioxidantes/metabolismo , Metabolismo Energético , China , Ecossistema , Mytilus/fisiologiaRESUMO
The salt-responsiveness of Pickering emulsions has significantly influenced their applications due to the large amount of salt on the surface of plant leaves. The present study provided a maleic anhydride-functionalized cellulose nanocrystal-stabilized high internal phase Pickering emulsion (MACNCs-HIPPEs) that was stable to high-concentration salt and used for pesticide delivery. The stability of MACNCs-HIPPEs was investigated by adjusting the oil-phase volume fraction (φ), the MACNCs concentration, NaCl dosages, and the rheological properties. The high internal phase Pickering emulsion was obtained at φ of 0.8 and MACNCs concentration of 2wt% and showed excellent salt stability (NaCl, 1200 mM) and significant storage stability (60 days). The sustained release of imidacloprid (IMI) from imidacloprid-loaded MACNCs-HIPPEs (IMI@MACNCs-HIPPEs) showed a positive correlation to the temperature (15°C, 25°C, 35°C), indicating clear thermo-responsiveness of the prepared pesticide formulation. The test of spread and retention of IMI@MACNCs-HIPPEs on the leaf surface showed a significant advantage compared with the commercial IMI water dispersible granules (CG). All the advantages mentioned above showed the excellent potential of the MACNCs-HIPPEs in delivering lipophilic pesticides.
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Celulose , Emulsões , Anidridos Maleicos , Nanopartículas , Neonicotinoides , Praguicidas , Celulose/química , Nanopartículas/química , Anidridos Maleicos/química , Emulsões/química , Praguicidas/química , Neonicotinoides/química , Nitrocompostos/química , Temperatura , Liberação Controlada de FármacosRESUMO
Background/Aims: Liver transplantation is the most effective treatment for the sickest patients with acute-on-chronic liver failure (ACLF). However, the influence of donor age on liver transplantation, especially in ACLF patients, is still unclear. Methods: In this study, we used the data of the Scientific Registry of Transplant Recipients. We included patients with ACLF who received liver transplantation from January 1, 2007, to December 31, 2017, and the total number was 13,857. We allocated the ACLF recipients by age into group I (donor age ≤17 years, n=647); group II (donor age 18-59 years, n=11,423); and group III (donor age ≥60 years, n=1,787). Overall survival (OS), graft survival, and mortality were compared among the three age groups and the four ACLF grades. Cox regression was also analyzed. Results: The 1-, 3-, and 5-year OS rates were 89.6%, 85.5%, and 82.0% in group I; 89.4%, 83.4%, and 78.2% in group II; and 86.8%, 78.4%, and 71.4% in group III, respectively (p<0.001). When we analyzed the different effects of donor age on OS with different ACLF grades, in groups II and III, we observed statistical differences. Finally, the cubic spline curve told us that the relative death rate changed linearly with increasing donor age. Conclusions: Donor age is related to OS and graft survival of ACLF patients after transplantation, and poorer results were associated with elderly donors. In addition, different donor ages have different effects on recipients with different ACLF grades.
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BACKGROUND: Bevacizumab resistance poses barriers to targeted therapy in clear cell renal cell carcinoma (ccRCC). Whether there exist epigenetic targets that modulate bevacizumab sensitivity in ccRCC remains indefinite. The focus of this study is to explore the role of UCHL1 in ccRCC. METHODS: Both in vitro and in vivo experiments were utilized to investigate the roles of UCHL1 in ccRCC. In vivo ubiquitination assays were performed to validate the posttranslational modification of KDM4B by UCHL1. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were utilized to explore KDM4B/VEGFA epigenetic regulations. RESULTS: UCHL1 was increased in ccRCC and associated with unfavorable survival outcomes in patients. UCHL1 was required for ccRCC growth and migration. Mechanistically, the wild-type UCHL1, but not C90A mutant, mediated the deubiquitination of KDM4B and thereby stabilized its proteins. KDM4B was up-regulated in ccRCC and potentiated cell growth. UCHL1 depended on KDM4B to augment ccRCC malignancies. Targeting UCHL1 suppressed tumor growth, colony formation, and migration abilities, which could be rescued by KDM4B. Furthermore, KDM4B was directly bound to the promoter region of VEGFA, abolishing repressive H3K9me3 modifications. KDM4B coordinated with HIF2α to activate VEGFA transcriptional levels. UCHL1-KDM4B axis governs VEGFA levels to sustain the angiogenesis phenotypes. Finally, a specific small-molecule inhibitor (6RK73) targeting UCHL1 remarkably inhibited ccRCC progression and further sensitized ccRCC to bevacizumab treatment. CONCLUSION: Overall, this study defined an epigenetic mechanism of UCHL1/KDM4B in activating VEGF signaling. The UCHL1-KDM4B axis represents a novel target for treating ccRCC and improving the efficacy of anti-angiogenesis therapy.
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Pathogen infections including Shigella flexneri have posed a significant threat to human health for numerous years. Although culturing and qPCR were the gold standards for pathogen detection, time-consuming and instrument-dependent restrict their application in rapid diagnosis and economically less-developed regions. Thus, it is urgently needed to develop rapid, simple, sensitive, accurate, and low-cost detection methods for pathogen detection. In this study, an immunomagnetic beads-recombinase polymerase amplification-CRISPR/Cas12a (IMB-RPA-CRISPR/Cas12a) method was built based on a cascaded signal amplification strategy for ultra-specific, ultra-sensitive, and visual detection of S. flexneri in the laboratory. Firstly, S. flexneri was specifically captured and enriched by IMB (Shigella antibody-coated magnetic beads), and the genomic DNA was released and used as the template in the RPA reaction. Then, the RPA products were mixed with the pre-loaded CRISPR/Cas12a for fluorescence visualization. The results were observed by naked eyes under LED blue light, with a sensitivity of 5 CFU/mL in a time of 70 min. With no specialized equipment or complicated technical requirements, the IMB-RPA-CRISPR/Cas12a diagnostic method can be used for visual, rapid, and simple detection of S. flexneri and can be easily adapted to monitoring other pathogens.
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Anticorpos , Shigella flexneri , Humanos , Luz Azul , Fluorescência , RecombinasesRESUMO
Purpose: Nonsense-mediated RNA decay (NMD), a surveillance pathway for selective degradation of aberrant mRNAs, is associated with cancer progression. Its potential as a predictor for aggressive hepatocellular carcinoma (HCC) is unclear. Here, we present an innovative NMD risk model for predicting HCC prognosis. Methods: The Cancer Genome Atlas (TCGA) data of 374 liver HCC (LIHC) and 50 normal liver samples were extracted. A risk model based on NMD-related genes was developed through least absolute shrinkage and selection operator Cox (LASSO-Cox) regression of the LIHC-TCGA data. Prognostic validation was done using GSE54236, GSE116174, and GSE76427 data. Univariate and multivariate Cox regression analyses were conducted to assess the prognostic value of the model. We also constructed nomograms for survival prediction. Tumor immune infiltration was evaluated using the CIBERSORT algorithm, and the tumor cell phenotype was assessed. Finally, mouse experiments verified UPF3B knockdown effects on HCC tumor characteristics. Results: We developed a risk model based on four NMD-related genes (PABPC1, RPL8, SMG5, and UPF3B) and validated it using GSE54236, GSE116174, and GSE76427 data. The model effectively distinguished high- and low-risk groups corresponding to unfavorable and favorable HCC outcomes. Its prognostic prediction accuracy was confirmed through time-dependent ROC analysis, and clinical-use nomograms with calibration curves were developed. Single-cell RNA sequencing results indicated significantly higher expression of SMG5 and UPF3B in tumor cells. Knockdown of SMG5 and UPF3B inhibited HCC cell proliferation, invasion, and migration, while affecting cell-cycle progression and apoptosis. In vivo, UPF3B knockdown delayed tumor growth and increased immune cell infiltration. Conclusion: Our NMD-related gene-based risk model can help identify therapeutic targets and biomarkers for HCC. Additionally, it assists clinicians in predicting the prognosis of HCC patients.
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BACKGROUND: Functional performance as measured by the Karnofsky Performance Status (KPS) scale has been linked to the outcomes of liver transplant patients; however, the effect of KPS on the outcomes of the hepatocellular carcinoma (HCC) liver transplant population has not been fully elucidated. We aimed to investigate the association between pre-transplant KPS score and long-term outcomes in HCC patients listed for liver transplantation. METHODS: Adult HCC candidates listed on the Scientific Registry of Transplant Recipients (SRTR) database from January 1, 2011 to December 31, 2017 were grouped into group I (KPS 80-100%, n = 8,379), group II (KPS 50-70%, n = 8,091), and group III (KPS 10-40%, n = 1,256) based on percentage KPS score at listing. Survival was compared and multivariable analysis was performed to identify independent predictors. RESULTS: Patients with low KPS score had a higher risk of removal from the waiting list. The 5-year intent-to-treat survival was 57.7% in group I, 53.2% in group II and 46.7% in group III (P < 0.001). The corresponding overall survival was 77.6%, 73.7% and 66.3% in three groups, respectively (P < 0.001). Multivariable analysis demonstrated that KPS was an independent predictor of intent-to-treat survival (P < 0.001, reference group I; HR 1.19 [95%CI 1.07-1.31] for group II, P = 0.001; HR 1.63 [95%CI 1.34-1.99] for group III, P < 0.001) and overall survival(P < 0.001, reference group I; HR 1.16 [95%CI 1.05-1.28] for group II, P = 0.004; HR 1.53 [95%CI 1.26-1.87] for group III, P < 0.001). The cumulative 5-year recurrence rates was higher in group III patients (7.4%), compared with 5.2% in group I and 5.5% in group II (P = 0.037). However, this was not significant in the competing regression analysis. CONCLUSIONS: Low pre-transplant KPS score is associated with inferior long-term survival in liver transplant HCC patients, but is not significantly associated with post-transplant tumor recurrence.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Transplante de Fígado , Adulto , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Avaliação de Estado de Karnofsky , Estudos Retrospectivos , Recidiva Local de Neoplasia , Prognóstico , Listas de EsperaRESUMO
The eukaryotic single-stranded DNA (ssDNA)-binding protein Replication Protein A (RPA) plays a crucial role in various DNA metabolic pathways, including DNA replication and repair, by dynamically associating with ssDNA. While the binding of a single RPA molecule to ssDNA has been thoroughly studied, the accessibility of ssDNA is largely governed by the bimolecular behavior of RPA, the biophysical nature of which remains unclear. In this study, we develop a three-step low-complexity ssDNA Curtains method, which, when combined with biochemical assays and a Markov chain model in non-equilibrium physics, allow us to decipher the dynamics of multiple RPA binding to long ssDNA. Interestingly, our results suggest that Rad52, the mediator protein, can modulate the ssDNA accessibility of Rad51, which is nucleated on RPA coated ssDNA through dynamic ssDNA exposure between neighboring RPA molecules. We find that this process is controlled by the shifting between the protection mode and action mode of RPA ssDNA binding, where tighter RPA spacing and lower ssDNA accessibility are favored under RPA protection mode, which can be facilitated by the Rfa2 WH domain and inhibited by Rad52 RPA interaction.
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DNA de Cadeia Simples , Rad51 Recombinase , Proteína de Replicação A , DNA de Cadeia Simples/genética , Proteínas de Ligação a DNA/genética , Proteína de Replicação A/genética , Rad51 Recombinase/genéticaRESUMO
Polychlorinated biphenyls (PCBs) and microplastics (MPs) commonly co-exist in various environments. MPs inevitably start aging once they enter environment. In this study, the effect of photo-aged polystyrene MPs on microbial PCB dechlorination was investigated. After a UV aging treatment, the proportion of oxygen-containing groups in MPs increased. Photo-aging promoted the inhibitory effect of MPs on microbial reductive dechlorination of PCBs, mainly attributed to the inhibition of meta-chlorine removal. The inhibitory effects on hydrogenase and adenosine triphosphatase activity by MPs increased with increasing aging degree, which may be attributed to electron transfer chain inhibition. PERMANOVA showed significant differences in microbial community structure between culturing systems with and without MPs (p < 0.05). Co-occurrence network showed a simpler structure and higher proportion of negative correlation in the presence of MPs, especially for biofilms, resulting in increased potential for competition among bacteria. MP addition altered microbial community diversity, structure, interactions, and assembly processes, which was more deterministic in biofilms than in suspension cultures, especially regarding the bins of Dehalococcoides. This study sheds light on the microbial reductive dechlorination metabolisms and mechanisms where PCBs and MPs co-exist and provides theoretical guidance for in situ application of PCB bioremediation technology.
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Bifenilos Policlorados , Envelhecimento da Pele , Bifenilos Policlorados/metabolismo , Microplásticos , Plásticos , Poliestirenos , Biodegradação Ambiental , Cloro/farmacologia , Cloro/metabolismo , Sedimentos Geológicos/microbiologiaRESUMO
BACKGROUND: NASH-related liver transplants are increasing because of the obesity epidemic, but the influence of T2DM on various levels of BMI among NASH recipients is unclear. RESEARCH DESIGN AND METHODS: We analyzed data retrieved from SRTR on 4,515 patients. We divided patients by BMI into five groups: normal weight; overweight; class 1 obesity; class 2 obesity; and class 3 obesity. Statistical analysis was done. RESULTS: Patients in the NASH group with T2DM had a lower patient and graft survival than patients without T2DM (5-year patient and graft survival: 77.5% vs. 79.8%; P = 0.001 and 76.4% vs. 78.2%; P = 0.002, respectively). Multivariate Cox proportional regression showed an independent association between T2DM and decreased patient and graft survival (HR, 1.170; P = 0.015 and HR, 1.133; P = 0.048, respectively). In the lean and the class 3 obesity NASH groups, patients with T2DM had lower patient and graft survival than the patients without T2DM. In the class 3 obesity NASH group, T2DM was independently associated with decreased patient survival (HR, 1.581; P = 0.027). CONCLUSION: Our research reveals that the focus of the post-transplantation treatment should be different for different BMI patients.
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Diabetes Mellitus Tipo 2 , Transplante de Fígado , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Hepatopatia Gordurosa não Alcoólica/cirurgia , Transplante de Fígado/efeitos adversos , Índice de Massa Corporal , Obesidade/complicações , Obesidade/diagnóstico , Obesidade/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Estudos Retrospectivos , Fatores de RiscoRESUMO
A 6500 V SiC trench MOSFET with integrated unipolar diode (UD-MOS) is proposed to improve reverse conduction characteristics, suppress bipolar degradation, and reduce switching loss. An N type base region under the trench dummy gate provides a low barrier path to suppress hole injection during the reverse conduction operation. The reverse conduction voltage VON is reduced to 1.11 V, and the reverse recovery charge (QRR) is reduced to 1.22 µC/cm2. The gate-to-drain capacitance (CGD) and gate-to-source capacitance (CGS) of the UD-MOS are also reduced to improve switching loss due to the thick oxide layer between the trench gate and dummy gate. The proposed device exhibits an excellent loss-related figure of merit (FOM). It provides a high-voltage SiC MOSFET prototype with potential performance advantages for voltage source converter-based high voltage direct current applications.
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Antimicrobial resistance in bacteria is the most urgent global threat to public health, with extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-E. coli) being one of the most documented examples. Nonetheless, the ESBL-E. coli transmission relationship among clinical sites and chicken farms remains unclear. Here, 408 ESBL-E. coli strains were isolated from hospitals and chicken farms in Sichuan Province and Yunnan Province in 2021. We detected blaCTX-M genes in 337 (82.62%) ESBL-E. coli strains. Although the isolation rate, prevalent sequence type (ST) subtypes, and blaCTX-M gene subtypes of ESBL-E. coli varied based on regions and sources, a few strains of CTX-ESBL-E. coli derived from clinical sites and chicken farms in Sichuan Province displayed high genetic similarity. This indicates a risk of ESBL-E. coli transmission from chickens to humans. Moreover, we found that the high-risk clonal strains ST131 and ST1193 primarily carried blaCTX-M-27. This indicates that drug-resistant E. coli from animal and human sources should be monitored. As well, the overuse of ß-lactam antibiotics should be avoided in poultry farms to ensure public health and build an effective regulatory mechanism of "farm to fork" under a One Health perspective. IMPORTANCE Bacterial drug resistance has become one of the most significant threats to human health worldwide, especially for extended-spectrum ß-lactamase-producing E. coli (ESBL-E. coli). Timely and accurate epidemiological surveys can provide scientific guidance for the adoption of treatments in different regions and also reduce the formation of drug-resistant bacteria. Our study showed that the subtypes of ESBL-E. coli strains prevalent in different provinces are somewhat different, so it is necessary to individualize treatment regimens in different regions, and it is especially important to limit and reduce antibiotic use in poultry farming since chicken-derived ESBL-E. coli serves as an important reservoir of drug resistance genes and has the potential to spread to humans, thus posing a threat to human health. The use of antibiotics in poultry farming should be particularly limited and reduced.
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Infecções por Escherichia coli , Escherichia coli , Animais , Humanos , Galinhas/microbiologia , Fazendas , Filogenia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Fatores de Virulência/genética , beta-Lactamases/genética , China/epidemiologia , Antibacterianos/farmacologia , Aves DomésticasRESUMO
Yolk-shell structure materials with the light weight, excellent impedance matching and electromagnetic wave (EMW) loss ability were widely used in the field of absorbing materials. However, the previous researches on this kind of structure always focused on the comparison between solid structure and empty structure. Different from previous studies, in this paper, the effect of yolk-shell structure with different air layer thickness on EMW absorption was studied for the first time. Graphene oxide (GO) supported yolk-shell ZnS/Ni3S4 absorbers with adjustable air layer were prepared by a simple two-step hydrothermal method. Through the equivalence of RLC resonant circuit and the elimination of the influence of polarization relaxation and conduction loss, it was found that yolk-shell structure with different air layer thickness will resonate with EMW of different frequencies, thus increasing the loss capacity of materials to EMW of this frequency. At the same time, Compared with the solid structure, the yolk-shell structure can not only make the material lighter, but also cause multiple reflections and scattering of EMW. Noteworthy, yolk-shell structure composite material exhibits the maximum reflection loss (RL) of -63.0 dB at 4.8 GHz and an effective absorption bandwidth (EAB) of 4.1 GHz at a thickness of 1.6 mm. This research provides an idea and basis for the design of absorbing materials that respond to different frequency EMW.
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Shigella flexneri is a serious threat to global public health, and a rapid detection method is urgently needed. The CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system is widely used in gene editing, gene therapy, and in vitro diagnosis. Here, we combined loop-mediated isothermal amplification (LAMP) and CRISPR/Cas12a to develop a novel diagnostic test (CRISPR/Cas12a-E-LAMP) for the diagnosis of S. flexneri. The CRISPR/Cas12a-E-LAMP protocol conducts LAMP reaction for S. flexneri templates followed by CRISPR/Cas12a detection of predefined target sequences. LAMP primers and sgRNAs were designed to the highly conserved gene hypothetical protein (accession: AE014073, region: 4170556-4171,068) of S. flexneri. After the LAMP reaction at 60°C for 20 min, the pre-loaded CRISPR/Cas12a regents were mixed with the LAMP products in one tube at 37°C for 20 min, and the final results can be viewed by naked eyes with a total time of 40 min. The sensitivity of CRISPR/Cas12a-E-LAMP to detect S. flexneri was 4 × 100 copies/µl plasmids and without cross-reaction with other six closely related non-S. flexneri. Therefore, the CRISPR/Cas12a-E-LAMP assay is a useful method for the reliable and quick diagnosis of S. flexneri and may be applied in other pathogen infection detection.
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BACKGROUND: Pulmonary fibrosis initiates a pneumonic cascade that leads to fibroblast dysfunction characterized by excess proliferation. Anoikis is a physiological process that ensures tissue development and homeostasis. Researchers have not clearly determined whether disruption of anoikis is involved in pulmonary fibrosis. RESULTS: Here, we investigated the mechanism by which silica induces fibroblast activation via anoikis resistance and subsequent fibrosis. Anoikis of lung fibroblasts, alveolar epithelial cells and endothelial cells during the process of fibrosis was detected using CCK-8, western blot, cell count and flow cytometry (FCM) assays. Although the three cell types showed similar increases in proliferation, the expression of NTRK2, a marker of anoikis resistance, was upregulated specifically in fibroblasts, indicating the unique proliferation mechanism of fibroblasts in pulmonary fibrosis, which may be related to anoikis resistance. Furthermore, the CRISPR/Cas9 system was used to investigate the molecular mechanism of anoikis resistance; the SiO2-induced inflammatory response activated the MAPK/PI3K signaling pathway in lung fibroblasts and then induced the expression of the ZC3H4 protein, which specifically mediated anoikis resistance, followed by pulmonary fibrosis. CONCLUSIONS: The current study revealed a specific pattern of fibroblast proliferation, and strategies targeting anoikis resistance may inhibit the pathological process of pulmonary fibrosis. This result provides a new approach for treating pulmonary fibrosis and new insights into the potential application of ZC3H4 in the development of novel therapeutic strategies for mitigating pulmonary fibrosis.
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m6A (N6-methyladenosine) is the most common type of RNA methylation modification, mainly occurring on mRNA. Whether m6A-modified circular RNAs (circRNAs) are involved in pulmonary fibrosis in different settings remains unclear. Using an m6A-circRNA epitranscriptomic chip, candidate circRNAs were selected, among which hsa_circ_0000672 and hsa_circ_0005654 were specifically involved in SiO2-induced pulmonary fibrosis by targeting the same protein, eIF4A3, indicating that the m6A modification of these two circRNAs has a synergistic effect on fibroblast dysfunction induced by SiO2. A mechanistic study revealed that the m6A modification of circRNAs was mainly mediated by the methyltransferase METTL3. Furthermore, METTL3 promoted the activation, migration, and activity of pulmonary fibroblasts and participated in SiO2-induced pulmonary fibrosis via the circRNA m6A modification. m6A methylation of circRNAs mediates silica-induced fibrosis, enriching the understanding of circRNAs and uncovering a potential new target for treating fibrosis-related diseases.
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Fibrose Pulmonar , RNA Circular , Adenosina/metabolismo , Humanos , Metilação , Metiltransferases/genética , Metiltransferases/metabolismo , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/genética , RNA Circular/genética , Dióxido de SilícioRESUMO
Many recent references show that living cells can form some membrane-less organelles by liquid-liquid phase separation (LLPS) of biomolecules, like proteins and nucleic acids. LLPS has been confirmed to link with many important biological functions in living cells, and one of the most important functions of biomolecular condensates is in the field of RNA transcription. Many studies confirm that mammalian RNA polymerase II (Pol II) molecules containing the CTD with different phosphorylation level are purposed to shuttle between initiation condensates and elongation condensates of RNA transcription. Traditional ensemble assays often experience difficulties in quantitively and directly recording the transient recruitment of Pol II CTD. Novel single-molecule approach - DNA curtains can be used to directly visualize biomolecular condensates formation and also recruitment of RNA polymerase II (Pol II) carboxyl-terminal domain (CTD) at the target sites in solution and in real time. This method can offer the potential for new insights into the mechanism of gene transcription. Here, we highlight the detailed protocol of DNA curtains method for studying LLPS.
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High-performance electromagnetic (EM) absorbers are necessary for military and industry application in view of the extensive utilization of EM devices. Carbon fibers (CFs) have been considered as promising candidates in electromagnetic wave (EMW) absorption materials, while the single carbon fiber material cannot achieve satisfactory EMW absorption performance because of its limited impedance matching. Herein, electrodeposition and hydrothermal methods were used to fabricate vertical hollow ZnS nanoarrays on carbon cloth (CC) substrate, and then one kind of novel flexible EM composite absorbers with excellent performance was obtained through adjusting morphology of hollow ZnS nanoarrays by easily changing the synthesis parameters of the precursor. Noteworthy, the miniaturized cone-shaped hollow ZnS nanoarray composite absorber shows excellent EMW absorption performance of strong absorption and wide absorption band. The maximum reflection loss value is -52.5 dB and the effective absorption bandwidth reaches 5.1 GHz when the thickness is only 1.9 mm. At the same time, the composite possesses the characteristics of light weight and thin thickness. The excellent properties of the composite absorbers are mainly attributed to their morphological structure. The unique hollow ZnS nanoarray structure enhances the interface polarization and multiple reflections, meanwhile also giving it the properties of metamaterials with resonant absorption. Furthermore, the adjustment of the ZnS nanoarray morphology can not only change the transmission behavior of EMW but also affect the resonance frequency and intensity of the ZnS nanoarray unit. This study obtains high-performance absorbing materials with flexible characteristics as well as highlights the importance of the adjustment of the morphological structure to improve the EMW absorption performance.
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The fusion genes resulting from chromosomal translocation have been found in many solid tumors or leukemia. EWS-FLI1, which belongs to the FUS/EWS/TAF15 (FET) family of fusion oncoproteins, is one of the most frequently involved fusion genes in Ewing sarcoma. These FET family fusion proteins typically harbor a low-complexity domain (LCD) of FET protein at their N-terminus and a DNA-binding domain (DBD) at their C-terminus. EWS-FLI1 has been confirmed to form biomolecular condensates at its target binding loci due to LCD-LCD and LCD-DBD interactions, and these condensates can recruit RNA polymerase II to enhance gene transcription. However, how these condensates are assembled at their binding sites remains unclear. Recently, a single-molecule biophysics method-DNA Curtains-was applied to visualize these assembling processes of EWS-FLI1 condensates. Here, the detailed experimental protocol and data analysis approaches are discussed for the application of DNA Curtains in studying the biomolecular condensates assembling on target DNA.
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Proteína Proto-Oncogênica c-fli-1 , Imagem Individual de Molécula , Linhagem Celular Tumoral , DNA , Regulação Neoplásica da Expressão Gênica , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/metabolismo , Proteína EWS de Ligação a RNARESUMO
OBJECTIVES: Shigella flexneri (S. flexneri) is prevalent worldwide and the most common Shigella in many countries, causing highly contagious diarrhea, which seriously threatens public health. This study aimed to develop a colorimetric loop-mediated isothermal amplification (LAMP) for the rapid, accurate, and visualization detection of S. flexneri. METHODS: According to the screened specific genes of S. flexneri, three groups of LAMP primers were designed and evaluated, and the colorimetric LAMP reaction volume was optimized. The specificity of the colorimetric LAMP was validated by 20 S. flexneri and 96 non-S. flexneri clinical isolates. In addition, the sensitivity of the developed assay was evaluated by the serial 10-fold dilutions of plasmid DNA. RESULTS: A colorimetric LAMP assay was developed based on the specific S. flexneri hypothetical protein gene (Accession: AE014073 Region: 4170556.4171068). The colorimetric LAMP method had good specificity for detecting S. flexneri and enabled detection of S. flexneri within 30 minutes, with a plasmid detection limit of 7*10° copies/µL. The results of amplification could be easily identified by color. CONCLUSIONS: This colorimetric LAMP assay could be used for rapid and accurate diagnosis of S. flexneri infection, especially in remote hospitals and laboratories with under-equipped medical facilities, and in situations where an urgent diagnosis is needed.