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1.
J Nematol ; 56(1): 20240033, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-39221106

RESUMO

Sweetpotato is an important crop whose roots are consumed by people worldwide. Meloidogyne enterolobii stands out as a highly deleterious variant among the species of root-knot nematode that causes significant damage in sweetpotato. In the present study, the activity of four nematicides against M. enterolobii was assessed both in vitro and in growth cabinet experiments. After 48 hours of exposure, fluopyram and cyclobutrifluram had a greater negative effect on the motility of M. enterolobii second-stage juveniles (J2s) compared to fluensulfone and hymexazol, with respective median effective concentration (EC50) values of 0.204, 0.423, 22.335 and 216.622 mg L-1. When M. enterolobii eggs were incubated for 72 hours at the highest concentration of each nematicides, the inhibitory hatching effect of cyclobutrifluram (2.5 mg L-1), fluopyram (1.25 mg L-1) and fluensulfone (80 mg L-1) surpassed 85%, whereas hymexazol (640 mg L-1) was only 67%. Similar results were observed in growth cabinet experiments as well. The disease index (DI) and gall index (GI) were significantly decreased by all four nematicides compared to the control. However, the application of hymexazol did not yield a statistically significant difference in the egg masses index compared to the control, a finding which may be attributed to its potentially limited penetrability through the eggshell barrier. Overall, this study has demonstrated that all four nematicides effectively suppress M. enterolobii in sweetpotato, and this is the first report on the nematicidal activity of cyclobutrifluram and hymexazol against M. enterolobii.

2.
Molecules ; 29(18)2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39339472

RESUMO

The Zn/Cr-MOFs/TiO2 composites were synthesized using the solvothermal method. XRD, FTIR, and SEM techniques were utilized to characterize the Zn/Cr-MOFs/TiO2 composites employed for simulating levofloxacin hydrochloride in wastewater. The impact of the mass of the Zn/Cr-MOFs/TiO2 composite, concentration of levofloxacin hydrochloride, solution pH, and temperature on the adsorption performance was investigated. Experimental findings indicated that at pH 6, the maximum removal efficiency of levofloxacin hydrochloride by the Zn/Cr-MOFs/TiO2 composite was achieved at 88.8%, with an adsorption capacity of 246.3 mg/g. To analyze the experimental data, both pseudo-first-order and pseudo-second-order kinetics models were applied, revealing that the pseudo-second-order model provided a better fit to the data. Additionally, Langmuir and Freundlich isotherm models were used to study equilibrium adsorption behavior and showed good agreement with both kinetic modeling and Langmuir isotherm analysis results. These observations suggest that monolayer adsorption predominates during the removal process of levofloxacin hydrochloride by Zn/Cr-MOFs/TiO2 composites.

3.
Mater Horiz ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39221699

RESUMO

As a unique structural form, helical structures have a wide range of application prospects. In the field of biology, helical structures are essential for the function of biological macromolecules such as proteins, so the study of helical structures can help to deeply understand life phenomena and develop new biotechnology. In materials science, helical structures can give rise to special physical and chemical properties, such as in the case of spiral nanotubes, helical fibers, etc., which are expected to be used in energy, environment, medical and other fields. The helical structure also has unique charm and application value in the fields of aesthetics and architecture. In addition, helical fibers have attracted a lot of attention because of their tendrils' vascular geometry and indispensable structural properties. In this paper, the development of helical fibers is briefly reviewed from the aspects of mechanism, synthesis process and application. Due to their good chemical and physical properties, helical fibers have a good application prospect in many fields. Potential problems and future opportunities for helical fibers are also presented for future studies.

4.
J Phys Chem A ; 128(37): 7889-7898, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39230386

RESUMO

The composite material, consisting of graphene oxide (GO) and chromium metal-organic frameworks (Cr-MOFs), was successfully synthesized by using a solvothermal method. The organic ligand employed was 2,5-dihydroxyterephthalic acid, while chromium acetate served as the source of the metal. The resulting material underwent characterization through Fourier transform infrared, scanning electron microscopy, and X-ray diffraction techniques. Subsequently, the adsorption capacity of the composite material toward moxifloxacin was evaluated. The results indicated a gradual increase in the moxifloxacin removal rate from GO/Cr-MOFs over time until reaching an equilibrium with a maximum removal rate of 90.4%. Additionally, it was observed that higher temperatures led to a decrease in the adsorption capacity. By incorporating 30 mg of GO/Cr-MOFs into a solution containing 40 ppm of moxifloxacin, the adsorption capacity could be maximized at 222.25 mg/g. Experimental data on MOF adsorption of moxifloxacin were analyzed using pseudo-first-order kinetics (PFO), pseudo-second-order kinetics (PSO), and Langmuir, Freundlich, and Temkin isotherm models for theoretical research purposes. Results showed that the PSO model exhibited a better correlation than the PFO model did. Furthermore, experimental data demonstrated good agreement with the Freundlich isothermal model, suggesting its effectiveness in accurately describing the adsorption process. Henceforth, it can be concluded that chemisorption plays a significant role in removing moxifloxacin by GO/Cr-MOFs. The van't Hoff equation analysis revealed an exothermic and spontaneous nature of moxifloxacin adsorption onto GO/Cr-MOFs. Compared to other materials, the GO/Cr-MOF composite exhibited high potential for applications such as drug removal or related fields.

5.
Molecules ; 29(16)2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39202951

RESUMO

In this study, Co/Cd-MOFs were synthesized via a solvothermal method. The resulting material was subjected to calcination at 900 °C for 2 h and characterized using FT-IR, XRD, and SEM techniques to assess its efficacy in moxifloxacin removal. The experimental findings revealed that the maximum adsorption capacity of Co/Cd-MOFs for moxifloxacin was observed at 350.4 mg/g within a 5 h timeframe. Furthermore, the analysis based on the pseudo-second-order kinetic model demonstrated that the adsorption process adhered to this specific model. Additionally, the adsorption isotherm analysis indicated that Freundlich multilayer adsorption provided the best description of the interaction between moxifloxacin and the Co/Cd-MOF material. These experimental and theoretical results collectively suggest that employing Co/Cd-MOFs as adsorbents holds promise for wastewater treatment applications.

6.
JACS Au ; 4(8): 2925-2935, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39211597

RESUMO

Anthraquinone-fused enediynes are anticancer natural products featuring a DNA-intercalating anthraquinone moiety. Despite recent insights into anthraquinone-fused enediyne (AQE) biosynthesis, the enzymatic steps involved in anthraquinone biogenesis remain to be elucidated. Through a combination of in vitro and in vivo studies, we demonstrated that a two-enzyme system, composed of a flavin adenine dinucleotide (FAD)-dependent monooxygenase (DynE13) and a cofactor-free enzyme (DynA1), catalyzes the final steps of anthraquinone formation by converting δ-thiolactone anthracene to hydroxyanthraquinone. We showed that the three oxygen atoms in the hydroxyanthraquinone originate from molecular oxygen (O2), with the sulfur atom eliminated as H2S. We further identified the key catalytic residues of DynE13 and A1 by structural and site-directed mutagenesis studies. Our data support a catalytic mechanism wherein DynE13 installs two oxygen atoms with concurrent desulfurization and decarboxylation, whereas DynA1 acts as a cofactor-free monooxygenase, installing the final oxygen atom in the hydroxyanthraquinone. These findings establish the indispensable roles of DynE13 and DynA1 in AQE biosynthesis and unveil novel enzymatic strategies for anthraquinone formation.

7.
Biomol Ther (Seoul) ; 32(5): 582-600, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39104205

RESUMO

Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment landscape for chronic myeloid leukemia (CML). However, TKI resistance poses a significant challenge, leading to treatment failure and disease progression. Resistance mechanisms include both BCR::ABL1-dependent and BCR::ABL1-independent pathways. The mechanisms underlying BCR::ABL1 independence remain incompletely understood, with CML cells potentially activating alternative signaling pathways, including the AKT/mTOR and JAK2/STAT5 pathways, to compensate for the loss of BCR::ABL1 kinase activity. This study explored tumoral VISTA (encoded by VSIR) as a contributing factor to TKI resistance in CML patients and identified elevated tumoral VISTA levels as a marker of resistance and poor survival. Through in vitro and in vivo analyses, we demonstrated that VSIR knockdown and the application of NSC-622608, a novel VISTA inhibitor, significantly impeded CML cell proliferation and induced apoptosis by attenuating the AKT/ mTOR and JAK2/STAT5 pathways, which are crucial for CML cell survival independent of BCR::ABL1 kinase activity. Moreover, VSIR overexpression promoted TKI resistance in CML cells. Importantly, the synergistic effect of NSC-622608 with TKIs offers a potent therapeutic avenue against both imatinib-sensitive and imatinib-resistant CML cells, including those harboring the challenging T315I mutation. Our findings highlight the role of tumoral VISTA in mediating TKI resistance in CML, suggesting that inhibition of VISTA, particularly in combination with TKIs, is an innovative approach to enhancing treatment outcomes in CML patients, irrespective of BCR::ABL1 mutation status. This study not only identified a new pathway contributing to TKI resistance but also revealed the possibility of targeting tumoral VISTA as a means of overcoming this significant clinical challenge.

8.
Mol Plant Pathol ; 25(7): e13496, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39011828

RESUMO

The second messenger cyclic diguanylate monophosphate (c-di-GMP) regulates a wide range of bacterial behaviours through diverse mechanisms and binding receptors. Single-domain PilZ proteins, the most widespread and abundant known c-di-GMP receptors in bacteria, act as trans-acting adaptor proteins that enable c-di-GMP to control signalling pathways with high specificity. This study identifies a single-domain PilZ protein, XAC3402 (renamed N5MapZ), from the phytopathogen Xanthomonas citri subsp. citri (Xcc), which modulates Xcc virulence by directly interacting with the methyltransferase HemK. Through yeast two-hybrid, co-immunoprecipitation and immunofluorescent staining, we demonstrated that N5MapZ and HemK interact directly under both in vitro and in vivo conditions, with the strength of the protein-protein interaction decreasing at high c-di-GMP concentrations. This finding distinguishes N5MapZ from other characterized single-domain PilZ proteins, as it was previously known that c-di-GMP enhances the interaction between those single-domain PilZs and their protein partners. This observation is further supported by the fact that the c-di-GMP binding-defective mutant N5MapZR10A can interact with HemK to inhibit the methylation of the class 1 translation termination release factor PrfA. Additionally, we found that HemK plays an important role in Xcc pathogenesis, as the deletion of hemK leads to extensive phenotypic changes, including reduced virulence in citrus plants, decreased motility, production of extracellular enzymes and stress tolerance. Gene expression analysis has revealed that c-di-GMP and the HemK-mediated pathway regulate the expression of multiple virulence effector proteins, uncovering a novel regulatory mechanism through which c-di-GMP regulates Xcc virulence by mediating PrfA methylation via the single-domain PilZ adaptor protein N5MapZ.


Assuntos
Proteínas de Bactérias , GMP Cíclico , Metiltransferases , Xanthomonas , Xanthomonas/patogenicidade , Xanthomonas/metabolismo , Xanthomonas/genética , GMP Cíclico/metabolismo , GMP Cíclico/análogos & derivados , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Metiltransferases/metabolismo , Metiltransferases/genética , Virulência , Doenças das Plantas/microbiologia , Ligação Proteica
10.
Cell Discov ; 10(1): 70, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38937452

RESUMO

KRAS mutations are highly prevalent in a wide range of lethal cancers, and these mutant forms of KRAS play a crucial role in driving cancer progression and conferring resistance to treatment. While there have been advancements in the development of small molecules to target specific KRAS mutants, the presence of undruggable mutants and the emergence of secondary mutations continue to pose challenges in the clinical treatment of KRAS-mutant cancers. In this study, we developed a novel molecular tool called tumor-targeting KRAS degrader (TKD) that effectively targets a wide range of KRAS mutants. TKD is composed of a KRAS-binding nanobody, a cell-penetrating peptide selectively targeting cancer cells, and a lysosome-binding motif. Our data revealed that TKD selectively binds to KRAS in cancer cells and effectively induces KRAS degradation via a lysosome-dependent process. Functionally, TKD suppresses tumor growth with no obvious side effects and enhances the antitumor effects of PD-1 antibody and cetuximab. This study not only provides a strategy for developing drugs targeting "undruggable" proteins but also reveals that TKD is a promising therapeutic for treating KRAS-mutant cancers.

11.
PLoS One ; 19(5): e0301714, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38713679

RESUMO

The development of intelligent education has led to the emergence of knowledge tracing as a fundamental task in the learning process. Traditionally, the knowledge state of each student has been determined by assessing their performance in previous learning activities. In recent years, Deep Learning approaches have shown promising results in capturing complex representations of human learning activities. However, the interpretability of these models is often compromised due to the end-to-end training strategy they employ. To address this challenge, we draw inspiration from advancements in graph neural networks and propose a novel model called GELT (Graph Embeddings based Lite-Transformer). The purpose of this model is to uncover and understand the relationships between skills and questions. Additionally, we introduce an energy-saving attention mechanism for predicting knowledge states that is both simple and effective. This approach maintains high prediction accuracy while significantly reducing computational costs compared to conventional attention mechanisms. Extensive experimental results demonstrate the superior performance of our proposed model compared to other state-of-the-art baselines on three publicly available real-world datasets for knowledge tracking.


Assuntos
Conhecimento , Redes Neurais de Computação , Humanos , Aprendizado Profundo , Algoritmos
12.
Inflammation ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38727856

RESUMO

RNA binding proteins (RBPs) have the potential for transcriptional regulation in sepsis-induced liver injury, but precise functions remain unclear. Our aim is to conduct a genome-wide expression analysis of RBPs and illuminate changes in the regulation of alternative splicing in sepsis-induced liver injury. RNA-seq data on "sepsis and liver" from the publicly available NCBI data set was analyzed, and differentially expressed RBPs and alternative splicing events (ASEs) in the healthy and septic liver were identified. Co-expression analyses of sepsis-regulated RBPs and ASEs were performed. Models of sepsis were established to validate hepatic RBP gene expression patterns with different treatments. Pairwise analysis of gene expression profiles of sham, cecum ligation puncture (CLP), and CLP with dichloroacetate (CLPDCA) mice allowed 1208 differentially expressed genes (DEGs), of which 800 were up-regulated and 408 down-regulated, to be identified. DEGs were similar in both Sham and CLPDCA mice. The KEGG analysis showed that up-regulated genes as being involved in cytokine-cytokine receptor interaction and IL-17 signaling pathway and down-regulated genes in metabolic pathways. Differences in lipid metabolism-related alternative splicing events, including A3SS, were also found in CLP and CLPDCA compared with sham mice. Thirty-seven RBPs, including S100a11, Ads2, Fndc3b, Fn1, Ddx28, Car2, Cisd1, and Ptms, were differentially expressed in CLP mice and the regulated alternative splicing genes(RASG) with the RBP shown to be enriched in lipid metabolic and oxidation-reduction-related processes by GO functional analysis. In KEEG analysis the RASG mainly enriched in metabolic pathway. The models of sepsis were constructed with different treatment groups, and S100a11 expression in the CLP group found to be higher than in the sham group, a change that was reversed by DCA. The alternative splicing ratio of Srebf1 and Cers2 decreased compared with the sham group increased after DCA treatment. Abnormal profiles of gene expression and alternative splicing were associated with sepsis-induced liver injury. Unusual expression of RBPs, such as S100a11, may regulate alternative splicing of lipid metabolism-associated genes, such as Srebf1 and Cers2, in the septic liver. RBPs may constitute potential treatment targets for sepsis-induced liver injury.

13.
Environ Res ; 252(Pt 3): 118941, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38649015

RESUMO

The Zn/Zr-MOFs were synthesized via microwave-assisted ball milling and subsequently characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The thermal stability of the Zn/Zr-MOFs was evaluated through thermogravimetry (TGA). The results demonstrated the exceptional adsorption properties of the Zn/Zr-MOFs towards Lomefloxacin hydrochloride and Levofloxacin hydrochloride. At a concentration of 30 ppm for Lomefloxacin hydrochloride, the addition of 30 mg of Zn/Zr-MOFs material resulted in an adsorption capacity of 179.2 mg•g-1. Similarly, at a concentration of 40 ppm for Levofloxacin hydrochloride, the addition of 30 mg Zn/Zr-MOFs material led to an adsorption capacity of 187.1 mg•g-1. Kinetic analysis revealed that the experimental data aligned well with a pseudo-second order kinetic model. Overall, these findings highlight the significant potential application of Zn/Zr-MOF materials in wastewater treatment.


Assuntos
Fluoroquinolonas , Levofloxacino , Micro-Ondas , Águas Residuárias , Poluentes Químicos da Água , Zinco , Levofloxacino/química , Adsorção , Fluoroquinolonas/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/análise , Zinco/química , Águas Residuárias/química , Zircônio/química , Antibacterianos/química , Cinética , Estruturas Metalorgânicas/química
14.
Shanghai Kou Qiang Yi Xue ; 33(1): 54-58, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38583025

RESUMO

PURPOSE: To compare the forming ability of four kinds of nickel-titanium instrument preparation resin for simulated curved root canal. METHODS: A total of 40 single bend resin simulated root canals were randomly divided into 4 groups with 10 in each group. Four kinds of nickel-titanium instruments (ProTaper, HyFlex EDM, WaveOne Gold and Reciproc Blue) were used for root canal preparation, and divided into group A, group B, group C and group D. The preparation time of the four groups was compared, the root canal images before and after preparation were analyzed by computer image analysis software, and the changes of the preparation time, curvature and curvature radius of the four groups were recorded. With the root tip as the center of the circle, the radius of 1-10 mm was selected as concentric circle arcs. The detection points were overlapping root canal intersection points. The resin removal amount and center positioning force of the inner and outer walls of the root canal at different detection points were recorded. Statistical analysis was performed with SPSS 20.0 software package. RESULTS: The root canal preparation time in group A was significant longer than that in group B, C and D(P<0.05), but there was no significant difference in the curvature and curvature radius of the root canal among the four groups (P>0.05). The removal amount of resin from the root canal wall in group C was significant lower than that in group A, B and D (P<0.05) when the distance from the detection point to the apical foramina was 5, 6, 8, 9 and 10 mm, respectively. The removal amount of resin from the outer wall of the root canal in group C was significant lower than that in group A, B and D (P<0.05) when the distance from the detection point to the apical foramina was 5, 6, 7, 9 and 10 mm, respectively. The root tip offset of group A from the detection point to the apical hole of 1, 2, 3, 4, 6, 7, 8, 9 and 10 mm was significant greater than that of group B, C and D(P<0.05). CONCLUSIONS: Among the four instruments, ProTaper has the largest apical deviation, HyFlex EDM, WaveOne Gold and Reciproc Blue have better ability of root canal forming.


Assuntos
Cavidade Pulpar , Titânio , Níquel , Instrumentos Odontológicos , Preparo de Canal Radicular/métodos , Desenho de Equipamento
15.
Cancer Lett ; 588: 216802, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38467180

RESUMO

Multiple myeloma (MM) is a hematological malignancy that remains incurable, primarily due to the high likelihood of relapse or development of resistance to current treatments. To explore and discover new medications capable of overcoming drug resistance in MM, we conducted cell viability inhibition screens of 1504 FDA-approved drugs. Lomitapide, a cholesterol-lowering agent, was found to exhibit effective inhibition on bortezomib-resistant MM cells in vitro and in vivo. Our data also indicated that lomitapide decreases the permeability of the mitochondrial outer membrane and induces mitochondrial dysfunction in MM cells. Next, lomitapide treatment upregulated DRP1 and PINK1 expression levels, coupled with the mitochondrial translocation of Parkin, leading to MM cell mitophagy. Excessive mitophagy caused mitochondrial damage and dysfunction induced by lomitapide. Meanwhile, PARP14 was identified as a direct target of lomitapide by SPR-HPLC-MS, and we showed that DRP1-induced mitophagy was crucial in the anti-MM activity mediated by PARP14. Furthermore, PARP14 is overexpressed in MM patients, implying that it is a novel therapeutic target in MM. Collectively, our results demonstrate that DRP1-mediated mitophagy induced by PARP14 may be the cause for mitochondrial dysfunction and damage in response to lomitapide treatment.


Assuntos
Benzimidazóis , Doenças Mitocondriais , Mieloma Múltiplo , Humanos , Mitofagia , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , Mitocôndrias/metabolismo , Recidiva Local de Neoplasia/patologia , Resistência a Medicamentos , Doenças Mitocondriais/metabolismo , Doenças Mitocondriais/patologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo
16.
ACS Synth Biol ; 13(4): 1259-1272, 2024 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-38513222

RESUMO

We present the newly isolated Streptomyces sungeiensis SD3 strain as a promising microbial chassis for heterologous production of secondary metabolites. S. sungeiensis SD3 exhibits several advantageous traits as a microbial chassis, including genetic tractability, rapid growth, susceptibility to antibiotics, and metabolic capability supporting secondary metabolism. Genomic and transcriptomic sequencing unveiled the primary metabolic capabilities and secondary biosynthetic pathways of S. sungeiensis SD3, including a previously unknown pathway responsible for the biosynthesis of streptazone B1. The unique placement of S. sungeiensis SD3 in the phylogenetic tree designates it as a type strain, setting it apart from other frequently employed Streptomyces chassis. This distinction makes it the preferred chassis for expressing biosynthetic gene clusters (BGCs) derived from strains within the same phylogenetic or neighboring phylogenetic clade. The successful expression of secondary biosynthetic pathways from a closely related yet slow-growing strain underscores the utility of S. sungeiensis SD3 as a heterologous expression chassis. Validation of CRISPR/Cas9-assisted genetic tools for chromosomal deletion and insertion paved the way for further strain improvement and BGC refactoring through rational genome editing. The addition of S. sungeiensis SD3 to the heterologous chassis toolkit will facilitate the discovery and production of secondary metabolites.


Assuntos
Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Filogenia , Antibacterianos/metabolismo , Genômica , Metabolismo Secundário/genética , Família Multigênica
17.
Biotechnol J ; 19(2): e2300542, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38403404

RESUMO

Bacterial second messenger c-di-GMP upregulation is associated with the transition from planktonic to sessile microbial lifestyle, inhibiting cellular motility, and virulence. However, in-depth elucidation of the cellular processes resulting from c-di-GMP upregulation has not been fully explored. Here, we report the role of upregulated cellular c-di-GMP in promoting planktonic cell growth of Escherichia coli K12 and Pseudomonas aeruginosa PAO1. We found a rapid expansion of cellular growth during initial cellular c-di-GMP upregulation, resulting in a larger planktonic bacterial population. The initial increase in c-di-GMP levels promotes bacterial swarming motility during the growth phase, which is subsequently inhibited by the continuous increase of c-di-GMP, and ultimately facilitates the formation of biofilms. We demonstrated that c-di-GMP upregulation triggers key bacterial genes linked to bacterial growth, swarming motility, and biofilm formation. These genes are mainly controlled by the master regulatory genes csgD and csrA. This study provides us a glimpse of the bacterial behavior of evading potential threats through adapting lifestyle changes via c-di-GMP regulation.


Assuntos
Proteínas de Bactérias , GMP Cíclico/análogos & derivados , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação para Cima , Biofilmes , Regulação Bacteriana da Expressão Gênica , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo
18.
J Biol Chem ; 300(3): 105741, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38340793

RESUMO

Type VI secretion systems (T6SS) are bacterial macromolecular complexes that secrete effectors into target cells or the extracellular environment, leading to the demise of adjacent cells and providing a survival advantage. Although studies have shown that the T6SS in Pseudomonas aeruginosa is regulated by the Quorum Sensing system and second messenger c-di-GMP, the underlying molecular mechanism remains largely unknown. In this study, we discovered that the c-di-GMP-binding adaptor protein PA0012 has a repressive effect on the expression of the T6SS HSI-I genes in P. aeruginosa PAO1. To probe the mechanism by which PA0012 (renamed TssZ, Type Six Secretion System -associated PilZ protein) regulates the expression of HSI-I genes, we conducted yeast two-hybrid screening and identified HinK, a LasR-type transcriptional regulator, as the binding partner of TssZ. The protein-protein interaction between HinK and TssZ was confirmed through co-immunoprecipitation assays. Further analysis suggested that the HinK-TssZ interaction was weakened at high c-di-GMP concentrations, contrary to the current paradigm wherein c-di-GMP enhances the interaction between PilZ proteins and their partners. Electrophoretic mobility shift assays revealed that the non-c-di-GMP-binding mutant TssZR5A/R9A interacts directly with HinK and prevents it from binding to the promoter of the quorum-sensing regulator pqsR. The functional connection between TssZ and HinK is further supported by observations that TssZ and HinK impact the swarming motility, pyocyanin production, and T6SS-mediated bacterial killing activity of P. aeruginosa in a PqsR-dependent manner. Together, these results unveil a novel regulatory mechanism wherein TssZ functions as an inhibitor that interacts with HinK to control gene expression.


Assuntos
Proteínas de Bactérias , Regulação Bacteriana da Expressão Gênica , Pseudomonas aeruginosa , Transcrição Gênica , Sistemas de Secreção Tipo VI , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Imunoprecipitação , Mutação , Regiões Promotoras Genéticas , Ligação Proteica , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Piocianina/metabolismo , Percepção de Quorum , Sistemas do Segundo Mensageiro , Técnicas do Sistema de Duplo-Híbrido , Sistemas de Secreção Tipo VI/genética , Sistemas de Secreção Tipo VI/metabolismo
19.
Expert Rev Gastroenterol Hepatol ; 18(1-3): 103-112, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38164659

RESUMO

OBJECTIVES: Metabolic-associated fatty liver disease (MAFLD) has clinical relevance in patients with acute-on-chronic liver failure (ACLF). We investigated the association between MAFLD and prognosis in patients with ACLF. METHODS: We included patients with ACLF with available clinical data who visited our hospital for nearly 9 years. We compared the prognosis of patients in the different subgroups of ACLF and predicted the incidence of adverse outcomes. Moreover, a new model based on MAFLD was established. RESULTS: Among 339 participants, 75 had MAFLD. The prognosis of patients with ACLF was significantly correlated with MAFLD. Patients with ACLF with concomitant MAFLD tended to have a lower cumulative survival rate (p = 0.026) and a higher incidence of hepatorenal syndrome (9.33% versus 3.40%, p = 0.033) than those without MAFLD. We developed an TIM2 model and the area under the ROC curve of the new model for 30-day and 60-day mortality (0.759 and 0.748) was higher than other predictive methods. CONCLUSION: The presence of MAFLD in patients with HBV-related ACLF was associated with an increased risk of in-hospital mortality. Moreover, The TIM2 model is a high-performance prognostic score for HBV-related ACLF.


Assuntos
Insuficiência Hepática Crônica Agudizada , Hepatopatia Gordurosa não Alcoólica , Humanos , Insuficiência Hepática Crônica Agudizada/diagnóstico , Insuficiência Hepática Crônica Agudizada/etiologia , Vírus da Hepatite B , Prognóstico , Curva ROC , Hepatopatia Gordurosa não Alcoólica/complicações , Estudos Retrospectivos
20.
Biosens Bioelectron ; 248: 115991, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38169279

RESUMO

The effective combination of ultra-precise detection and on-demand sterilization stands out as one of the most valuable antifouling methods to combat pathogenic bacteria source and ensure the environment and food safety. Herein, an innovative "five birds one stone" aptasensor has been reported. It integrates magnetic separation, tri-modal precision detection, and efficient sterilization for monitoring of Staphylococcus aureus. Firstly, as a switch of the aptasensor, aptamer-modified potassium chloride-doped carbon dots (apt/KCl@CDs) could be adsorbed onto the surface of magnetic multi-walled carbon nanotube composites (M-MWCNTs) through π-π stacking, which could be replaced by the specific binding of the target bacteria to the aptamer. The mutual interference between the nanomaterials could be eliminated by this reverse magnetosorption strategy, enhancing the test sensitivity. In addition to the fluorescence properties, the peroxidase activity possessed by apt/KCl@CDs enables the conversion of the (3,3',5,5'-tetramethylbenzidine) TMB-H2O2 colorimetric system to a photothermal modal. Then, the ultra-precision detection in the assay was achieved by the fluorescence-colorimetric-photothermal tri-modal sensing from the formation of S. aureus-apt/KCl@CDs in the supernatant. Besides, the efficient sterilization could be ensured by adsorbing the apt/KCl@CDs on the surface of S. aureus, generating toxic •OH for direct attacking cells. This was the first report that was more beneficial for bacterial eradication. The detection limits of fluorescence, colorimetric and photothermal modals were 4.81 cfu/mL, 3.40 cfu/mL and 6.74 cfu/mL, respectively. The magnetic nanoplatform integrating tri-modal detection-sterilization meets the demand for highly sensitive and precise detection in different scenarios, providing immediate control for pathogens and broad application prospects.


Assuntos
Anti-Infecciosos , Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Staphylococcus aureus/química , Peróxido de Hidrogênio , Técnicas Biossensoriais/métodos , Bactérias , Fenômenos Magnéticos , Limite de Detecção , Aptâmeros de Nucleotídeos/química
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