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1.
ISME J ; 18(1)2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38959853

RESUMEN

Effector proteins secreted by bacteria that infect mammalian and plant cells often subdue eukaryotic host cell defenses by simultaneously affecting multiple targets. However, instances when a bacterial effector injected in the competing bacteria sabotage more than a single target have not been reported. Here, we demonstrate that the effector protein, LtaE, translocated by the type IV secretion system from the soil bacterium Lysobacter enzymogenes into the competing bacterium, Pseudomonas protegens, affects several targets, thus disabling the antibacterial defenses of the competitor. One LtaE target is the transcription factor, LuxR1, that regulates biosynthesis of the antimicrobial compound, orfamide A. Another target is the sigma factor, PvdS, required for biosynthesis of another antimicrobial compound, pyoverdine. Deletion of the genes involved in orfamide A and pyoverdine biosynthesis disabled the antibacterial activity of P. protegens, whereas expression of LtaE in P. protegens resulted in the near-complete loss of the antibacterial activity against L. enzymogenes. Mechanistically, LtaE inhibits the assembly of the RNA polymerase complexes with each of these proteins. The ability of LtaE to bind to LuxR1 and PvdS homologs from several Pseudomonas species suggests that it can sabotage defenses of various competitors present in the soil or on plant matter. Our study thus reveals that the multi-target effectors have evolved to subdue cell defenses not only in eukaryotic hosts but also in bacterial competitors.


Asunto(s)
Proteínas Bacterianas , Lysobacter , Pseudomonas , Sistemas de Secreción Tipo IV , Pseudomonas/genética , Pseudomonas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Lysobacter/genética , Lysobacter/metabolismo , Sistemas de Secreción Tipo IV/genética , Sistemas de Secreción Tipo IV/metabolismo , Regulación Bacteriana de la Expresión Génica , Oligopéptidos/metabolismo , Oligopéptidos/genética , Transactivadores/genética , Transactivadores/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factor sigma/genética , Factor sigma/metabolismo
2.
Inorg Chem ; 63(26): 12073-12080, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38946340

RESUMEN

Luminescent materials typically emit their fluorescence or phosphorescence at a specific wavelength with different excitation energies via the so-called Kasha's rule. If fluorescence or phosphorescence emission via anti-Kasha's rule could be achieved, it will hold great promise for applications in many fields. In this work, we report the synthesis and characterization of new metal-organic halide materials with dual emission of efficient room-temperature phosphorescence and fluorescence, which obey anti-Kasha's rule. Here, three emitting metal-organic halides with formula [ZnX2(bidpe)] (X = Cl for 1, X = Br for 2, X = I for 3, bidpe = 4,4'-bis(imidazol-1-yl)diphenyl ether) were prepared and their photophysical properties were investigated. The complexes exhibit dual emission of fluorescence and phosphorescence via anti-Kasha's rule, and their RTP properties of resultant products are modulated by halide substitution synthesis. DFT calculations indicate that the singlet states exhibit a halide-ligand charge transfer (XLCT) character while the triplet states are dominated by the intraligand π-π* transitions. Furthermore, the multilevel information encryption and anticounterfeiting applications are developed by virtue of anti-Kasha's rule emission.

3.
Int J Biol Macromol ; 276(Pt 1): 133871, 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39009257

RESUMEN

Camptothecin (CPT) is a monoterpenoid indole alkaloid with a wide spectrum of anticancer activity. However, its application is hindered by poor solubility, lack of targeting specificity, and severe side effects. Structural derivatization of CPT and the development of suitable drug delivery systems are potential strategies for addressing these issues. In this study, we discovered that the protein Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) from Homo sapiens catalyzes CPT to yield 9-hydroxycamptothecin (9-HCPT), which exhibits increased water solubility and cytotoxicity. We then created a RNA-protein complex based drug delivery system with enzyme and pH responsiveness and improved the targeting and stability of the nanomedicine through protein module assembly. The subcellular localization of nanoparticles can be visualized using fluorescent RNA probes. Our results not only identified the protein CYP1A1 responsible for the structural derivatization of CPT to synthesize 9-HCPT but also offered potential strategies for enhancing the utilization of silk-based drug delivery systems in tumor therapy.

4.
Artículo en Inglés | MEDLINE | ID: mdl-39019048

RESUMEN

Precise segmentation for skin cancer lesions at different stages is conducive to early detection and further treatment. Considering the huge cost of obtaining pixel-perfect annotations for this task, segmentation using less expensive image-level labels has become a research direction. Most image-level label weakly supervised segmentation uses class activation mapping (CAM) methods. A common consequence of this method is incomplete foreground segmentation, insufficient segmentation, or false negatives. At the same time, when performing weakly supervised segmentation of skin cancer lesions, ulcers, redness, and swelling may appear near the segmented areas of individual disease categories. This co-occurrence problem affects the model's accuracy in segmenting class-related tissue boundaries to a certain extent. The above two issues are determined by the loosely constrained nature of image-level labels that penalize the entire image space. Therefore, providing pixel-level constraints for weak supervision of image-level labels is the key to improving performance. To solve the above problems, this paper proposes a joint unsupervised constraint-assisted weakly supervised segmentation model(UCA-WSS). The weakly supervised part of the model adopts a dual-branch adversarial erasure mechanism to generate higher-quality CAM. The unsupervised part uses contrastive learning and clustering algorithms to generate foreground labels and fine boundary labels to assist segmentation and solve common co-occurrence problems in weakly supervised skin cancer lesion segmentation through unsupervised constraints. The model proposed in the article is evaluated comparatively with other related models on some public dermatology data sets. Experimental results show that our model performs better on the skin cancer segmentation task than other weakly supervised segmentation models, showing the potential of combining unsupervised constraint methods on weakly supervised segmentation.

5.
Food Chem X ; 22: 101522, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38883917

RESUMEN

Histamine is a biogenic amine with various physiological functions. However, excessive consumption of histamine can lead to various symptoms, and pose a threat to human lives. A ratiometric fluorescent test strip for visual detection of histamine was developed based on CB-Ni2+@CDs probes. As the concentration of histamine increases, the test strips exhibit a transition in fluorescence signal from yellow-green to blue. The RGB values were extracted from the images, and used for quantitative analysis of histamine. The method had a linear range of 0-1.0 mM, with a detection limit of 0.086 mM. The test strips were employed for the detection of histamine, and the recovery rate was found to be in the range of 88.3% to 104.69%, indicating a high level of accuracy. The uniqueness of the test strips lies in their ability to be produced simply by mixing CB, Ni2+ on a suitable polyvinyl alcohol/wood cellulose fiber substrate.

6.
Front Microbiol ; 15: 1395504, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38841069

RESUMEN

Persister cells are transiently tolerant to antibiotics and are associated with recalcitrant chronic infections due to recolonization of host cells after antibiotic removal. Brucella spp. are facultative pathogens that establish intracellular infection cycles in host cells which results in chronic persistent infections. Brucella abortus forms multi-drug persister cells which are promoted by the (p)ppGpp synthetase Rsh during rifampicin exposure. Here, we confirmed that Rsh promoted persister cells formation in B. abortus stationary phase treated with rifampicin and enrofloxacin. Deletion of the gene for Rsh decreased persister cells level in the presence of these drugs in different growth phases. However, persister cells formation by deletion strain varied in different growth phases in the presence of other antibiotics. Rsh also was involved in persister cells formation during rifampicin treatment under certain stress conditions, including acidic conditions, exposure to PBS, and heat stress. Moreover, Rsh impacted persister cell levels during rifampicin or enrofloxacin treatment in RAW264.7 macrophages. Certain typeIItoxin-antitoxin modules were upregulated under various stress conditions in B. abortus. We established that Rsh positively regulated the type II toxin-antitoxin mbcTA. Moreover, rifampicin-tolerant persister cells formation was elevated and ATP levels were decreased when mbcTA promoter was overexpressed in Rsh deletion background in stationary phase. Our results establish that (p)ppGpp synthetase Rsh plays a key role in B. abortus persistence and may serve as a potent novel target in combination with rifampicin in the development of new therapeutic approaches and prevention strategies to treat chronic infections of Brucella.

8.
BMC Cancer ; 24(1): 761, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38918775

RESUMEN

High-grade B-cell lymphoma (HGBCL), the subtype of non-Hodgkin lymphoma, to be relapsed or refractory in patients after initial therapy or salvage chemotherapy. Dual dysregulation of MYC and BCL2 is one of the important pathogenic mechanisms. Thus, combined targeting of MYC and BCL2 appears to be a promising strategy. Dihydroorotate dehydrogenase (DHODH) is the fourth rate-limiting enzyme for the de novo biosynthesis of pyrimidine. It has been shown to be a potential therapeutic target for multiple diseases. In this study, the DHODH inhibitor brequinar exhibited growth inhibition, cell cycle blockade, and apoptosis promotion in HGBCL cell lines with MYC and BCL2 rearrangements. The combination of brequinar and BCL2 inhibitors venetoclax had a synergistic inhibitory effect on the survival of DHL cells through different pathways. Venetoclax could upregulate MCL-1 and MYC expression, which has been reported as a resistance mechanism of BCL2 inhibitors. Brequinar downregulated MCL-1 and MYC, which could potentially overcome drug resistance to venetoclax in HGBCL cells. Furthermore, brequinar could downregulate a broad range of genes, including ribosome biosynthesis genes, which might contribute to its anti-tumor effects. In vivo studies demonstrated synergetic tumor growth inhibition in xenograft models with brequinar and venetoclax combination treatment. These results provide preliminary evidence for the rational combination of DHODH and BCL2 blockade in HGBCL with abnormal MYC and BCL2.


Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes , Dihidroorotato Deshidrogenasa , Sinergismo Farmacológico , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Proto-Oncogénicas c-myc , Sulfonamidas , Ensayos Antitumor por Modelo de Xenoinjerto , Humanos , Animales , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratones , Sulfonamidas/farmacología , Sulfonamidas/uso terapéutico , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Línea Celular Tumoral , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/genética , Apoptosis/efectos de los fármacos , Linfoma de Células B/tratamiento farmacológico , Linfoma de Células B/genética , Linfoma de Células B/patología , Linfoma de Células B/metabolismo , Reordenamiento Génico , Proliferación Celular/efectos de los fármacos , Compuestos de Bifenilo , Quinaldinas
9.
Poult Sci ; 103(9): 103967, 2024 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-38941789

RESUMEN

Periplaneta americana residue is a byproduct of using Periplaneta americana in pharmaceutical research and development for extracting active ingredients. Three hundred Three-yellow chickens were selected for the experiment and randomly divided into 6 groups (5 replications per group, 10 chickens per replicate): the control group (group A) was fed a basal ration, and the experimental groups (groups B, C, D, E, and F) were fed experimental diets in which P. americana residue replaced puffed soybean meal at proportions of 20, 40, 60, 80, and 100%, respectively, for a period of 42 d. The aim was to assess the impact of different levels of P. americana residue on the growth, survival, intestinal morphology, digestive enzyme activity, intestinal flora, and intestinal transcriptional responses of Three-yellow chickens. The results indicated that the increase in P. americana residue levels had a linear and quadratic impact on the average daily gain (ADG) and feed conversion ratio (FCR), respectively. The ADG was notably greater in the 40% group than in the 100% group, while the FCR was significantly lower in the 20% and 40% groups than in the 100% group (P < 0.05). Protease, lipase, and amylase activities exhibited a quadratic increase with increasing concentrations of P. americana residue (P < 0.05). Protease and lipase activities were notably greater in the 20% and 40% groups than in the 0% group (control group), amylase activity was significantly greater in the 40% group than in the 0% group (control group) (P < 0.05). Duodenal crypt depth (CD) decreased quadratically with increasing P. americana residue (P < 0.05). The duodenal villus height/crypt depth ratio (V/C) was significantly lower in the 100% group than in the 60% group (P < 0.05). The intestinal villus height (VH) increased quadratically with increasing levels of P. americana residue. The VH in the 60% group was significantly greater than that in the 0% (control group), 20, 80, and 100% groups (P < 0.05). The Chao and Ace indices demonstrated linear and quadratic increases with increasing levels of P. americana residue, while the Pd index showed a quadratic increase with increasing levels of P. americana residue (P < 0.05). The relative abundance profile of Lactobacillus exhibited a linear and quadratic decrease with increasing levels of P. americana residue, with the 100% group showing a significantly lower abundance than the 0% (control group) and 40% groups (P < 0.05). The transcriptome results showed that P. americana residue could enhance the digestive system by promoting vitamin, fat, carbohydrate digestion and absorption, cholesterol metabolism, etc. In conclusion, P. americana residue can replace puffed soybean meal without negatively affecting the growth performance of three-yellow chickens. The low and medium groups had positive effects on the growth performance, digestive enzyme activity, intestinal morphology, intestinal flora, and substance digestion and absorption of three-yellow chickens. The recommended replacement of P. americana residue for puffed soybean meal in the diets of three-yellow chickens ranged from 20% to 60%.

11.
Environ Sci Technol ; 58(22): 9536-9547, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38771144

RESUMEN

Recent studies found the intrusion and retention of exogenous fine particles into joints, but epidemiological data for long- and intermediate-term exposure associations are scare. Here, all urban working, retired employee, and rural residents (16.78 million) in Beijing from January 1, 2011 to December 31, 2019 were included to investigate the effects of long- and intermediate-term ambient particulate exposure on development of osteoarthritis. We identified 1,742,067 participants as first-visit patients with osteoarthritis. For each interquartile range increase in annual PM2.5 (23.32 µg/m3) and PM10 (23.92 µg/m3) exposure concentration, the pooled hazard ratios were respectively 1.238 (95% CI: 1.228, 1.249) and 1.178 (95% CI: 1.168, 1.189) for first osteoarthritis outpatient visits. Moreover, age at first osteoarthritis outpatient visits significantly decreased by 4.52 (95% CI: 3.45 to 5.40) days per µg/m3 for annual PM2.5 exposure at below 67.85 µg/m3. Finally, among the six constituents analyzed, black carbon appears to be the most important component associated with the association between PM2.5 exposure and the three osteoarthritis-related outcomes.


Asunto(s)
Osteoartritis , Material Particulado , Humanos , Osteoartritis/epidemiología , Estudios Prospectivos , Contaminación del Aire , Masculino , Contaminantes Atmosféricos , Femenino , Exposición a Riesgos Ambientales , Persona de Mediana Edad , Factores de Riesgo , Beijing/epidemiología , Anciano
12.
Artículo en Inglés | MEDLINE | ID: mdl-38713566

RESUMEN

Achieving accurate bladder wall and tumor segmentation from MRI is critical for diagnosing and treating bladder cancer. However, automated segmentation remains challenging due to factors such as comparable density distributions, intricate tumor morphologies, and unclear boundaries. Considering the attributes of bladder MRI images, we propose an efficient multiscale hierarchical hybrid attention with a transformer (MH2AFormer) for bladder cancer and wall segmentation. Specifically, a multiscale hybrid attention and transformer (MHAT) module in the encoder is designed to adaptively extract and aggregate multiscale hybrid feature representations from the input image. In the decoder stage, we devise a multiscale hybrid attention (MHA) module to generate high-quality segmentation results from multiscale hybrid features. Combining these modules enhances the feature representation and guides the model to focus on tumor and wall regions, which helps to solve bladder image segmentation challenges. Moreover, MHAT utilizes the Fast Fourier Transformer with a large kernel (e.g., 224*******224) to model global feature relationships while reducing computational complexity in the encoding stage. The model performance was evaluated on two datasets. As a result, the model achieves relatively best results regarding the intersection over union (IoU) and dice similarity coefficient (DSC) on both datasets (Dataset A: IoU=80.26%, DSC=88.20%; Dataset B: IoU=89.74%, DSC=94.48%). These advantageous outcomes substantiate the practical utility of our approach, highlighting its potential to alleviate the workload of radiologists when applied in clinical settings.

13.
Anim Biotechnol ; 35(1): 2349625, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38733367

RESUMEN

This study aimed to evaluate the genetic diversity and structure within the Dengchuan cattle population and effectively protect and utilize their germplasm resources. Herein, the single-nucleotide polymorphisms (SNPs) of 100 Dengchuan cattle (46 bulls and 54 cows) were determined using the GGP Bovine 100K SNP Beadchip. The results showed that among the Dengchuan cattle, a total of 101,220 SNPs were detected, and there were 83,534 SNPs that passed quality control, of which 85.7% were polymorphic. The average genetic distance based on identity-by-state (IBS) within the conservation population of Dengchuan cattle was 0.26 ± 0.02. A total of 3,999 genome-length runs of homozygosity (ROHs) were detected in the Dengchuan cattle, with ROH lengths primarily concentrated in the range of 1-5 Mb, accounting for 87.02% of the total. The average inbreeding coefficient based on ROHs was 4.6%, within the conservation population of Dengchuan cattle, whereas it was 4.9% for bulls, and the Wright inbreeding coefficient (FIS) value was 2.4%, demonstrating a low level of inbreeding within the Dengchuan cattle population. Based on neighbor-joining tree analysis, the Dengchuan cattle could be divided into 16 families. In summary, the conservation population of Dengchuan cattle displays relatively abundant diversity and a moderate genetic relationship. Inbreeding was observed among a few individuals, but the overall inbreeding level of the population remained low. It is important to maintain this low level of inbreeding when introducing purebred bloodlines to expand the core group. This approach will ensure the long-term conservation of Dengchuan cattle germplasm resources and prevent loss of genetic diversity.


Asunto(s)
Polimorfismo de Nucleótido Simple , Animales , Bovinos/genética , Polimorfismo de Nucleótido Simple/genética , Variación Genética , Especies en Peligro de Extinción , Masculino , Endogamia , Femenino , Genética de Población , China
14.
Plant Physiol ; 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38709681

RESUMEN

Cuticular wax is a protective layer on the aerial surfaces of land plants. In Arabidopsis (Arabidopsis thaliana), cuticular wax is mainly constituted of compounds derived from very-long-chain fatty acids (VLCFAs) with chain lengths longer than C28. CER2-LIKE (ECERIFERUM2-LIKE) proteins interact with CER6/KCS6 (ECERIFERUM6/ß-Ketoacyl-CoA Synthase6), the key enzyme of the fatty acid elongase complex, to modify its substrate specificity for VLCFA elongation past C28. However, the molecular regulatory mechanism of CER2-LIKE proteins remains unclear. Arabidopsis eceriferum19 (cer19) mutants display wax-deficient stems caused by loss of waxes longer than C28, indicating that CER19 may participate in the CER2-LIKE-mediated VLCFA elongation past C28. Using positional cloning and genetic complementation, we showed that CER19 encodes Acetyl-CoA Carboxylase1 (ACC1), which catalyzes the synthesis of malonyl-CoA, the essential substrate for the CER6/KCS6-mediated condensation reaction in VLCFA synthesis. We demonstrated that ACC1 physically interacts with CER2-LIKE proteins via split-ubiquitin yeast two-hybrid (SUY2H) and firefly luciferase complementation imaging (LCI) analysis. Additionally, heterologous expression in yeast and genetic analysis in Arabidopsis revealed that ACC1 affects CER2 activity to influence VLCFA elongation past C28. These findings imply that CER2-LIKE proteins might function as a link between ACC1 and CER6/KCS6 and subsequently enhance CER6/KCS6 binding to malonyl-CoA for further utilization in VLCFA elongation past C28. This information deepens our understanding of the complex mechanism of cuticular wax biosynthesis.

15.
Int J Biol Macromol ; 269(Pt 2): 131954, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38697424

RESUMEN

Silk fibroin (SF) from the cocoon of silkworm has exceptional mechanical properties and biocompatibility and is used as a biomaterial in a variety of fields. Sustainable, affordable, and scalable manufacturing of SF would enable its large-scale use. We report for the first time the high-level secretory production of recombinant SF peptides in engineered Pichia pastoris cell factories and the processing thereof to nanomaterials. Two SF peptides (BmSPR3 and BmSPR4) were synthesized and secreted by P. pastoris using signal peptides and appropriate spacing between hydrophilic sequences. By strain engineering to reduce protein degradation, increase glycyl-tRNA supply, and improve protein secretion, we created the optimized P. pastoris chassis PPGSP-8 to produce BmSPR3 and BmSPR4. The SF fed-batch fermentation titers of the resulting two P. pastoris cell factories were 11.39 and 9.48 g/L, respectively. Protein self-assembly was inhibited by adding Tween 80 to the medium. Recombinant SF peptides were processed to nanoparticles (NPs) and nanofibrils. The physicochemical properties of nanoparticles R3NPs and R4NPs from the recombinant SFs synthesized in P. pastoris cell factories were similar or superior to those of RSFNPs (Regenerated Silk Fibroin NanoParticles) originating from commercially available SF. Our work will facilitate the production by microbial fermentation of functional SF for use as a biomaterial.


Asunto(s)
Fibroínas , Proteínas Recombinantes , Fibroínas/química , Fibroínas/biosíntesis , Fibroínas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/biosíntesis , Nanoestructuras/química , Fermentación , Saccharomycetales/metabolismo , Saccharomycetales/genética , Seda/química , Seda/biosíntesis , Animales , Bombyx/metabolismo , Bombyx/genética
16.
Front Nutr ; 11: 1341827, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38765811

RESUMEN

Essential oils have been recognized for their strong antibacterial property, making them an innovative approach for preserving meat. However, their chemical instability and direct impact on meat proteins limit their application. To overcome these limitations, various loading systems have been explored. This study aimed to compare the effect of cinnamon essential oil (CEO) loaded in a liposome and emulsion system on the proteolysis of minced pork and to evaluate the advantages of each delivery system in preventing microorganism-induced quality deterioration of meat. Minced pork treated with CEO-liposomes exhibited lower pH, total volatile basic nitrogen (TVB-N), and total viable count (TVC) values than CEO-emulsions and provided better protection against microorganisms. SDS-polyacrylamide gel electrophoresis (PAGE) analysis confirmed that CEO-liposome was more effective in protecting proteins from degradation. Moreover, CEO-liposome produced lower amount of bitter amino acids and harmful biogenic amines. Antibacterial mechanisms indicated that CEO-liposome exhibited a stronger inhibitory effect against major spoilage bacteria in meat products by increasing cell membrane permeability. The membrane damage was further supported by an increase in conductivity and the leakage of nucleic acids. Compared to the CEO-emulsion system, CEO-liposome emerged as an effective preservative for minced pork. These results provided important theoretical support for using a bioactive compound delivery system to prevent microorganism-induced quality deterioration in meat.

17.
ACS Biomater Sci Eng ; 10(5): 2995-3005, 2024 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-38654432

RESUMEN

Magnetic hyperthermia is a crucial medical engineering technique for treating diseases, which usually uses alternating magnetic fields (AMF) to interplay with magnetic substances to generate heat. Recently, it has been found that in some cases, there is no detectable temperature increment after applying an AMF, which caused corresponding effects surprisingly. The mechanisms involved in this phenomenon are not yet fully understood. In this study, we aimed to explore the role of Ca2+ overload in the magnetic hyperthermia effect without a perceptible temperature rise. A cellular system expressing the fusion proteins TRPV1 and ferritin was prepared. The application of an AMF (518 kHz, 16 kA/m) could induce the fusion protein to release a large amount of iron ions, which then participates in the production of massive reactive oxygen radicals (ROS). Both ROS and its induced lipid oxidation enticed the opening of ion channels, causing intracellular Ca2+ overload, which further led to decreased cellular viability. Taken together, Ca2+ overload triggered by elevated ROS and the induced oxidation of lipids contributes to the magnetic hyperthermia effect without a perceptible temperature rise. These findings would be beneficial for expanding the application of temperature-free magnetic hyperthermia, such as in cellular and neural regulation, design of new cancer treatment methods.


Asunto(s)
Calcio , Supervivencia Celular , Hipertermia Inducida , Campos Magnéticos , Especies Reactivas de Oxígeno , Canales Catiónicos TRPV , Calcio/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Canales Catiónicos TRPV/metabolismo , Humanos , Hipertermia Inducida/métodos , Temperatura , Ferritinas/metabolismo , Hipertermia/metabolismo
18.
ACS Chem Biol ; 19(5): 1151-1160, 2024 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-38648729

RESUMEN

Magnetogenetics has shown great potential for cell function and neuromodulation using heat or force effects under different magnetic fields; however, there is still a contradiction between experimental effects and underlying mechanisms by theoretical computation. In this study, we aimed to investigate the role of reactive oxygen species (ROS) in mechanical force-dependent regulation from a physicochemical perspective. The transient receptor potential vanilloid 4 (TRPV4) cation channels fused to ferritin (T4F) were overexpressed in HEK293T cells and exposed to static magnetic fields (sMF, 1.4-5.0 mT; gradient: 1.62 mT/cm). An elevation of ROS levels was found under sMF in T4F-overexpressing cells, which could lead to lipid oxidation. Compared with the overexpression of TRPV4, ferritin in T4F promoted the generation of ROS under the stimulation of sMF, probably related to the release of iron ions from ferritin. Then, the resulting ROS regulated the opening of the TRPV4 channel, which was attenuated by the direct addition of ROS inhibitors or an iron ion chelator, highlighting a close relationship among iron release, ROS production, and TRPV4 channel activation. Taken together, these findings indicate that the produced ROS under sMF act on the TRPV4 channel, regulating the influx of calcium ions. The study would provide a scientific basis for the application of magnetic regulation in cellular or neural regulation and disease treatment and contribute to the development of the more sensitive regulatory technology.


Asunto(s)
Ferritinas , Campos Magnéticos , Especies Reactivas de Oxígeno , Canales Catiónicos TRPV , Canales Catiónicos TRPV/metabolismo , Humanos , Especies Reactivas de Oxígeno/metabolismo , Células HEK293 , Ferritinas/metabolismo , Ferritinas/química , Hierro/metabolismo , Calcio/metabolismo
19.
Brain Circ ; 10(1): 77-84, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38655440

RESUMEN

PURPOSE: In patients undergoing endovascular thrombectomy (EVT) with acute ischemic stroke (AIS), dynamic cerebral autoregulation (dCA) may minimize neurological injury from blood pressure fluctuations. This study set out to investigate the function of dCA in predicting clinical outcomes following EVT. METHODS: 43 AIS of the middle cerebral or internal carotid artery patients underwent with EVT, and 43 healthy individuals (controls) were enrolled in this case control research. The dCA was evaluated using transcranial Doppler 12 h and five days after EVT. The transfer function analysis was used to derive the dCA parameters, such as phase, gain, and coherence. The modified Rankin scale (mRS) at 3 months after EVT was used to assess the clinical outcomes. Thefavorable outcome group was defined with mRS ≤2 and the unfavorable outcome group was defined with mRS score of 3-6. Logistic regression analysis was performed to determine the risk factors of clinical outcomes. RESULTS: A significant impairment in dCA was observed on the ipsilateral side after EVT, particularly in patients with unfavorable outcomes. After 5 days, the ipsilateral phase was associated with poor functional outcomes (adjusted odds ratio [OR] = 0.911, 95% confidence interval [CI]: 0.854-0.972; P = 0.005) and the area under the curve (AUC) (AUC, 0.878, [95% CI: 0.756-1.000] P < 0.001) (optimal cutoff, 35.0°). Phase change was an independent predictor of clinical outcomes from 12 h to 5 days after EVT (adjusted OR = 1.061, 95% CI: 1.016-1.109, P = 0.008). CONCLUSIONS: dCA is impaired in patients with AIS after EVT. Change in dCA could be an independent factor related to the clinical outcomes.

20.
BMC Infect Dis ; 24(1): 403, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38622539

RESUMEN

BACKGROUND: Monkeypox is an emerging infectious disease with confirmed cases and deaths in several parts of the world. In light of this crisis, this study aims to analyze the global knowledge pattern of monkeypox-related patents and explore current trends and future technical directions in the medical development of monkeypox to inform research and policy. METHODS: A comprehensive study of 1,791 monkeypox-related patents worldwide was conducted using the Derwent patent database by descriptive statistics, social network method and linear regression analysis. RESULTS: Since the 21st century, the number of monkeypox-related patents has increased rapidly, accompanied by increases in collaboration between commercial and academic patentees. Enterprises contributed the most in patent quantity, whereas the initial milestone patent was filed by academia. The core developments of technology related to the monkeypox include biological and chemical medicine. The innovations of vaccines and virus testing lack sufficient patent support in portfolios. CONCLUSIONS: Monkeypox-related therapeutic innovation is geographically limited with strong international intellectual property right barriers though it has increased rapidly in recent years. The transparent licensing of patent knowledge is driven by the merger and acquisition model, and the venture capital, intellectual property and contract research organization model. Currently, the patent thicket phenomenon in the monkeypox field may slow the progress of efforts to combat monkeypox. Enterprises should pay more attention to the sharing of technical knowledge, make full use of drug repurposing strategies, and promote innovation of monkeypox-related technology in hotspots of antivirals (such as tecovirimat, cidofovir, brincidofovir), vaccines (JYNNEOS, ACAM2000), herbal medicine and gene therapy.


Asunto(s)
Enfermedades Transmisibles Emergentes , Mpox , Vacunas , Humanos , Enfermedades Transmisibles Emergentes/tratamiento farmacológico , Enfermedades Transmisibles Emergentes/epidemiología , Mpox/tratamiento farmacológico , Mpox/epidemiología , Tecnología
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