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1.
Nature ; 601(7892): 205-210, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35022592

RESUMO

Fermi liquid theory forms the basis for our understanding of the majority of metals: their resistivity arises from the scattering of well defined quasiparticles at a rate where, in the low-temperature limit, the inverse of the characteristic time scale is proportional to the square of the temperature. However, various quantum materials1-15-notably high-temperature superconductors1-10-exhibit strange-metallic behaviour with a linear scattering rate in temperature, deviating from this central paradigm. Here we show the unexpected signatures of strange metallicity in a bosonic system for which the quasiparticle concept does not apply. Our nanopatterned YBa2Cu3O7-δ (YBCO) film arrays reveal linear-in-temperature and linear-in-magnetic field resistance over extended temperature and magnetic field ranges. Notably, below the onset temperature at which Cooper pairs form, the low-field magnetoresistance oscillates with a period dictated by the superconducting flux quantum, h/2e (e, electron charge; h, Planck's constant). Simultaneously, the Hall coefficient drops and vanishes within the measurement resolution with decreasing temperature, indicating that Cooper pairs instead of single electrons dominate the transport process. Moreover, the characteristic time scale τ in this bosonic system follows a scale-invariant relation without an intrinsic energy scale: h/τ ≈ a(kBT + γµBB), where h is the reduced Planck's constant, a is of order unity7,8,11,12, kB is Boltzmann's constant, T is temperature, µB is the Bohr magneton and γ ≈ 2. By extending the reach of strange-metal phenomenology to a bosonic system, our results suggest that there is a fundamental principle governing their transport that transcends particle statistics.


Assuntos
Elétrons , Supercondutividade , Campos Magnéticos , Metais , Temperatura
2.
Proc Natl Acad Sci U S A ; 120(1): e2209990120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36577069

RESUMO

Microglia play a critical role in the clearance of myelin debris, thereby ensuring functional recovery from neural injury. Here, using mouse model of demyelination following two-point LPC injection, we show that the microglial autophagic-lysosomal pathway becomes overactivated in response to severe demyelination, leading to lipid droplet accumulation and a dysfunctional and pro-inflammatory microglial state, and finally failed myelin debris clearance and spatial learning deficits. Data from genetic approaches and pharmacological modulations, via microglial Atg5 deficient mice and intraventricular BAF A1 administration, respectively, demonstrate that staged suppression of excessive autophagic-lysosomal activation in microglia, but not sustained inhibition, results in better myelin debris degradation and exerts protective effects against demyelination. Combined multi-omics results in vitro further showed that enhanced lipid metabolism, especially the activation of the linoleic acid pathway, underlies this protective effect. Supplementation with conjugated linoleic acid (CLA), both in vivo and in vitro, could mimic these effects, including attenuating inflammation and restoring microglial pro-regenerative properties, finally resulting in better recovery from demyelination injuries and improved spatial learning function, by activating the peroxisome proliferator-activated receptor (PPAR-γ) pathway. Therefore, we propose that pharmacological inhibition targeting microglial autophagic-lysosomal overactivation or supplementation with CLA could represent a potential therapeutic strategy in demyelinated disorders.


Assuntos
Doenças Desmielinizantes , Microglia , Camundongos , Animais , Microglia/metabolismo , Ácido Linoleico/metabolismo , Autofagia , Doenças Desmielinizantes/metabolismo , Regeneração
3.
Brain ; 147(1): 163-176, 2024 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-37740498

RESUMO

Microglia-mediated neuroinflammation contributes to acute demyelination in neuromyelitis optica spectrum disorders (NMOSD). Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in the CSF has been associated with microglial activation in several neurodegenerative diseases. However, the basis for this immune-mediated attack and the pathophysiological role of sTREM2 in NMOSD remain to be elucidated. Here, we performed Mendelian randomization analysis and identified a genetic association between increased CSF sTREM2 and NMOSD risk. CSF sTREM2 was elevated in patients with NMOSD and was positively correlated with neural injury and other neuroinflammation markers. Single-cell RNA sequencing of human macrophage/microglia-like cells in CSF, a proxy for microglia, showed that increased CSF sTREM2 was positively associated with microglial dysfunction in patients with NMOSD. Furthermore, we demonstrated that sTREM2 is a reliable biomarker of microglial activation in a mouse model of NMOSD. Using unbiased transcriptomic and lipidomic screens, we identified that excessive activation, overwhelmed phagocytosis of myelin debris, suppressed lipid metabolism and enhanced glycolysis underlie sTREM2-mediated microglial dysfunction, possibly through the nuclear factor kappa B (NF-κB) signalling pathway. These molecular and cellular findings provide a mechanistic explanation for the genetic association between CSF sTREM2 and NMOSD risk and indicate that sTREM2 could be a potential biomarker of NMOSD progression and a therapeutic target for microglia-mediated neuroinflammation.


Assuntos
Doença de Alzheimer , Neuromielite Óptica , Animais , Camundongos , Humanos , Microglia/metabolismo , Doença de Alzheimer/metabolismo , Neuromielite Óptica/genética , Neuromielite Óptica/metabolismo , Doenças Neuroinflamatórias , Biomarcadores/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Receptores Imunológicos/genética
4.
Proc Natl Acad Sci U S A ; 119(36): e2205629119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36037365

RESUMO

Elimination of autoreactive developing B cells is an important mechanism to prevent autoantibody production. However, how B cell receptor (BCR) signaling triggers apoptosis of immature B cells remains poorly understood. We show that BCR stimulation up-regulates the expression of the lysosomal-associated transmembrane protein 5 (LAPTM5), which in turn triggers apoptosis of immature B cells through two pathways. LAPTM5 causes BCR internalization, resulting in decreased phosphorylation of SYK and ERK. In addition, LAPTM5 targets the E3 ubiquitin ligase WWP2 for lysosomal degradation, resulting in the accumulation of its substrate PTEN. Elevated PTEN levels suppress AKT phosphorylation, leading to increased FOXO1 expression and up-regulation of the cell cycle inhibitor p27Kip1 and the proapoptotic molecule BIM. In vivo, LAPTM5 is involved in the elimination of autoreactive B cells and its deficiency exacerbates autoantibody production. Our results reveal a previously unidentified mechanism that contributes to immature B cell apoptosis and B cell tolerance.


Assuntos
Apoptose , Tolerância Imunológica , Proteínas de Membrana , Células Precursoras de Linfócitos B , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Proteína Forkhead Box O1/metabolismo , Humanos , Lisossomos/metabolismo , Proteínas de Membrana/genética , PTEN Fosfo-Hidrolase/metabolismo , Células Precursoras de Linfócitos B/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
5.
J Am Chem Soc ; 146(6): 4178-4186, 2024 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-38301245

RESUMO

DNA origami, comprising a long folded DNA scaffold and hundreds of linear DNA staple strands, has been developed to construct various sophisticated structures, smart devices, and drug delivery systems. However, the size and diversity of DNA origami are usually constrained by the length of DNA scaffolds themselves. Herein, we report a new paradigm of scaling up DNA origami assembly by introducing a novel branched staple concept. Owing to their covalent characteristics, the chemically conjugated branched DNA staples we describe here can be directly added to a typical DNA origami assembly system to obtain super-DNA origami with a predefined number of origami tiles in one pot. Compared with the traditional two-step coassembly system (yields <10%), a much greater yield (>80%) was achieved using this one-pot strategy. The diverse superhybrid DNA origami with the combination of different origami tiles can be also efficiently obtained by the hybrid branched staples. Furthermore, the branched staples can be successfully employed as the effective molecular glues to stabilize micrometer-scale, super-DNA origami arrays (e.g., 10 × 10 array of square origami) in high yields, paving the way to bridge the nanoscale precision of DNA origami with the micrometer-scale device engineering. This rationally developed assembly strategy for super-DNA origami based on chemically conjugated branched staples presents a new avenue for the development of multifunctional DNA origami-based materials.


Assuntos
Nanoestruturas , Nanoestruturas/química , Nanotecnologia , DNA/química , Análise de Sequência com Séries de Oligonucleotídeos , Conformação de Ácido Nucleico
6.
Anal Chem ; 96(10): 4138-4145, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38426857

RESUMO

Calcification and abnormal collagen deposition within blood vessels constitute causative factors for atherosclerotic plaque rupture, and their occurrence is intimately linked with γ-glutamyltranspeptidase (GGT) and hypobromous acid (HOBr). However, the underlying regulatory mechanisms of GGT and HOBr in plaque rupture remain unclear. Hence, we developed a dual-responsive near-infrared (NIR) fluorescent probe (BOC-H) that effectively avoids spectral crosstalk for the in situ visualization of the fluctuations in GGT and HOBr levels during atherosclerotic plaque rupture. We found that both GGT and HOBr contents increase significantly in the calcification models of cells and animals. The overexpressed GGT participated in intracellular oxygen-promoting behavior, which obviously upregulated the expression of RunX2 and Col IV by facilitating H2O2 and HOBr secretion. This process triggered calcification and abnormal collagen deposition within the plaque, which raised the risk of plaque rupture. PM2.5-induced arteriosclerotic calcification models further verified the results that GGT and HOBr accelerate plaque rupture via activation of the RunX2/Col IV signaling pathway. Moreover, the assessment of GGT and HOBr in serum samples from patients with acute myocardial infarction further confirmed the co-regulation of GGT and HOBr in the plaque rupture. Together, our studies highlight the involvement of GGT and HOBr in driving plaque rupture and offer new targets for the prevention and treatment of acute cardiovascular disease.


Assuntos
Bromatos , Placa Aterosclerótica , Animais , Humanos , Placa Aterosclerótica/diagnóstico por imagem , Peróxido de Hidrogênio , Transdução de Sinais , Colágeno
7.
Appl Environ Microbiol ; 90(2): e0109023, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38259075

RESUMO

Acetate is a major intermediate in the anaerobic digestion of organic waste to produce CH4. In methanogenic systems, acetate degradation is carried out by either acetoclastic methanogenesis or syntrophic degradation by acetate oxidizers and hydrogenotrophic methanogens. Due to challenges in the isolation of syntrophic acetate-oxidizing bacteria (SAOB), the diversity and metabolism of SAOB and the mechanisms of their interactions with methanogenic partners are not fully characterized. In this study, the in situ activity and metabolic characteristics of potential SAOB and their interactions with methanogens were elucidated through metagenomics and metatranscriptomics. In addition to the reported SAOB classified in the genera Tepidanaerobacter, Desulfotomaculum, and Thermodesulfovibrio, we identified a number of potential SAOB that are affiliated with Clostridia, Thermoanaerobacteraceae, Anaerolineae, and Gemmatimonadetes. The potential SAOB possessing the glycine-mediated acetate oxidation pathway dominates SAOB communities. Moreover, formate appeared to be the main product of the acetate degradation by the most active potential SAOB. We identified the methanogen partner of these potential SAOB in the acetate-fed chemostat as Methanosarcina thermophila. The dominated potential SAOB in each chemostat had similar metabolic characteristics, even though they were in different fatty-acid-fed chemostats. These novel syntrophic lineages are prevalent and may play critical roles in thermophilic methanogenic reactors. This study expands our understanding of the phylogenetic diversity and in situ biological functions of uncultured syntrophic acetate degraders and presents novel insights into how they interact with methanogens.IMPORTANCECombining reactor operation with omics provides insights into novel uncultured syntrophic acetate degraders and how they perform in thermophilic anaerobic digesters. This improves our understanding of syntrophic acetate degradation and contributes to the background knowledge necessary to better control and optimize anaerobic digestion processes.


Assuntos
Bactérias , Euryarchaeota , Filogenia , Acetatos/metabolismo , Bactérias Anaeróbias/metabolismo , Euryarchaeota/metabolismo , Anaerobiose , Oxirredução , Firmicutes/metabolismo , Metano/metabolismo , Reatores Biológicos/microbiologia
8.
BMC Microbiol ; 24(1): 158, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720268

RESUMO

BACKGROUND: The production of succinic acid (SA) from biomass has attracted worldwide interest. Saccharomyces cerevisiae is preferred for SA production due to its strong tolerance to low pH conditions, ease of genetic manipulation, and extensive application in industrial processes. However, when compared with bacterial producers, the SA titers and productivities achieved by engineered S. cerevisiae strains were relatively low. To develop efficient SA-producing strains, it's necessary to clearly understand how S. cerevisiae cells respond to SA. RESULTS: In this study, we cultivated five S. cerevisiae strains with different genetic backgrounds under different concentrations of SA. Among them, KF7 and NBRC1958 demonstrated high tolerance to SA, whereas NBRC2018 displayed the least tolerance. Therefore, these three strains were chosen to study how S. cerevisiae responds to SA. Under a concentration of 20 g/L SA, only a few differentially expressed genes were observed in three strains. At the higher concentration of 60 g/L SA, the response mechanisms of the three strains diverged notably. For KF7, genes involved in the glyoxylate cycle were significantly downregulated, whereas genes involved in gluconeogenesis, the pentose phosphate pathway, protein folding, and meiosis were significantly upregulated. For NBRC1958, genes related to the biosynthesis of vitamin B6, thiamin, and purine were significantly downregulated, whereas genes related to protein folding, toxin efflux, and cell wall remodeling were significantly upregulated. For NBRC2018, there was a significant upregulation of genes connected to the pentose phosphate pathway, gluconeogenesis, fatty acid utilization, and protein folding, except for the small heat shock protein gene HSP26. Overexpression of HSP26 and HSP42 notably enhanced the cell growth of NBRC1958 both in the presence and absence of SA. CONCLUSIONS: The inherent activities of small heat shock proteins, the levels of acetyl-CoA and the strains' potential capacity to consume SA all seem to affect the responses and tolerances of S. cerevisiae strains to SA. These factors should be taken into consideration when choosing host strains for SA production. This study provides a theoretical basis and identifies potential host strains for the development of robust and efficient SA-producing strains.


Assuntos
Regulação Fúngica da Expressão Gênica , Saccharomyces cerevisiae , Ácido Succínico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Ácido Succínico/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fermentação
9.
Toxicol Appl Pharmacol ; 489: 117017, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38925513

RESUMO

Liver fibrosis, a progressive process of fibrous scarring, results from the accumulation of extracellular matrix proteins (ECM). If left untreated, it often progresses to diseases such as cirrhosis and hepatocellular carcinoma. Lycorine, a natural alkaloid derived from medicinal plants, has shown diverse bioactivities by targeting JAK2/STAT3 signaling, but its pharmacological effects and potential molecular mechanisms in liver fibrosis remains largely unexplored. The purpose of this study is to elucidate the pharmacological activity and molecular mechanism of lycorine in anti-hepatic fibrosis. Findings indicate that lycorine significantly inhibited hepatic stellate cells (HSCs) activation by reducing the expression of α-SMA and collagen-1. In vivo, lycorine treatment alleviated carbon tetrachloride (CCl4) -induced mice liver fibrosis, improving liver function, decreasing ECM deposition, and inhibiting fibrosis-related markers' expression. Mechanistically, it was found that lycorine exerts protective activity through the JAK2/STAT3 and PI3K/AKT signaling pathways, as evidenced by transcriptome sequencing technology and small molecule inhibitors. These results underscore lycorine's potential as a therapeutic drug for liver fibrosis.


Assuntos
Alcaloides de Amaryllidaceae , Tetracloreto de Carbono , Células Estreladas do Fígado , Janus Quinase 2 , Cirrose Hepática , Fenantridinas , Proteínas Proto-Oncogênicas c-akt , Fator de Transcrição STAT3 , Transdução de Sinais , Animais , Janus Quinase 2/metabolismo , Fator de Transcrição STAT3/metabolismo , Alcaloides de Amaryllidaceae/farmacologia , Tetracloreto de Carbono/toxicidade , Transdução de Sinais/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Camundongos , Masculino , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/patologia , Cirrose Hepática/metabolismo , Fenantridinas/farmacologia , Fenantridinas/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Camundongos Endogâmicos C57BL , Linhagem Celular
10.
Brain Behav Immun ; 119: 416-430, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38636563

RESUMO

The role of microglia in triggering the blood-brain barrier (BBB) impairment and white matter damage after chronic cerebral hypoperfusion is unclear. Here we demonstrated that the vessel-adjacent microglia were specifically activated by the leakage of plasma low-density lipoprotein (LDL), which led to BBB breakdown and ischemic demyelination. Interestingly, we found that LDL stimulation enhanced microglial phagocytosis, causing excessive engulfment of myelin debris and resulting in an overwhelming lipid burden in microglia. Surprisingly, these lipid-laden microglia exhibited a suppressed profile of inflammatory response and compromised pro-regenerative properties. Microglia-specific knockdown of LDLR or systematic medication lowering circulating LDL-C showed protective effects against ischemic demyelination. Overall, our findings demonstrated that LDL-stimulated vessel-adjacent microglia possess a disease-specific molecular signature, characterized by suppressed regenerative properties, which is associated with the propagation of demyelination during ischemic white matter damage.


Assuntos
Barreira Hematoencefálica , Isquemia Encefálica , Lipoproteínas LDL , Microglia , Substância Branca , Microglia/metabolismo , Animais , Substância Branca/metabolismo , Substância Branca/patologia , Camundongos , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Isquemia Encefálica/metabolismo , Barreira Hematoencefálica/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Doenças Desmielinizantes/metabolismo , Doenças Desmielinizantes/patologia , Fagocitose/fisiologia , Bainha de Mielina/metabolismo
11.
Anticancer Drugs ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38995659

RESUMO

OBJECTIVE: The aim of this study was to establish a simple and sensitive high-performance liquid chromatography method for therapeutic drug monitoring of venetoclax (VEN) and optimize regimens. METHODS: The analysis required the extraction of a 50 µl plasma sample and the precipitation of proteins using acetonitrile extraction. The chromatographic method employed a mobile phase of acetonitrile: 0.5% KH2PO4 (pH 3.5) (60/40, v/v) on a Diamond C18 (4.6 mm × 250 mm, 5 µm) column at a flow rate of 1.0 ml/min. The quantitative method was validated based on standards described in 'Bioanalytical Method Validation: Guidance for Industry' published by the US Food and Drug Administration (FDA). RESULTS: The calibration curve was linear (R2 = 0.9998) over the range of 75-4800 ng/ml, with limits of quantification of 25 ng/ml. The coefficients of intraday and interday validation, specificity, recovery, and stability all met the criteria of FDA guidance. The method was successfully applied to analyze VEN concentrations in 30 cases of acute myeloid leukemia patients. The peak concentration (Cmax) was 1881.19 ±â€…756.61 ng/ml, while the trough concentration (Cmin) was 1212.69 ±â€…767.92 ng/ml in acute myeloid leukemia patients. CONCLUSION: Our study establishes a simple, precise, and sensitive high-performance liquid chromatography method for monitoring VEN and confirms its applicability for therapeutic drug monitoring of VEN in hematological cancers.

12.
Inorg Chem ; 63(17): 7848-7857, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38635372

RESUMO

To systematically investigate the dependence of the initiating group and metal size on polymerization performance, a family of rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes supported by a monoanionic tridentate amidinate ligand [(2,6-iPr2C6H3)NC(Ph)N(C6H4-2-OMe]- (HL) were synthesized and well-characterized. Treatment of rare-earth metal tris(alkyl)/tris(benzyl)/tris(amide) complexes Y(CH2C6H4NMe2-o)3 or Y(CH2SiMe3)3(THF)2 or Ln[N(SiHMe2)2]3(THF)x (Ln = Sc, x = 1; Ln = Y, La, Sm, Lu, x = 2) with 1 equiv of HL gave the corresponding mono(amidinate) rare-earth metal bis(alkyl)/bis(benzyl)/bis(amide) complexes [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Y(CH2C6H4NMe2-o)2 (1), [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Y(CH2SiMe3)2(THF) (2), and [(2,6-iPr2C6H4)NC(Ph)N(C6H4-2-OMe)]Ln[N(SiHMe2)2]2(THF)n (Ln = Y, n = 1 (3); Ln = La, n = 1 (4); Ln = Sc, n = 0 (5); Ln = Lu, n = 0 (6); Ln = Sm, n = 0 (7)) in good isolated yields. These complexes were characterized by elemental analysis, NMR spectroscopy, and single-crystal X-ray diffraction. In the presence of excess AlMe3 and on treatment with 1 equiv of [Ph3C][B(C6F5)4], these complexes could serve as precatalysts for cationic polymerization of isoprene, in which the dependence of the polymerization activity and regioselectivity on the initiating group and metal size was observed.

13.
Methods ; 212: 12-20, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36858137

RESUMO

Gut microbiota plays a crucial role in modulating pig development and health, and gut microbiota characteristics are associated with differences in feed efficiency. To answer open questions in feed efficiency analysis, biologists seek to retrieve information across multiple heterogeneous data sources. However, this is error-prone and time-consuming work since the queries can involve a sequence of multiple sub-queries over several databases. We present an implementation of an ontology-based Swine Gut Microbiota Federated Query Platform (SGMFQP) that provides a convenient, automated, and efficient query service about swine feeding and gut microbiota. The system is constructed based on a domain-specific Swine Gut Microbiota Ontology (SGMO), which facilitates the construction of queries independent of the actual organization of the data in the individual sources. This process is supported by a template-based query interface. A Datalog+-based federated query engine transforms the queries into sub-queries tailored for each individual data source, and an automated workflow orchestration mechanism executes the queries in each source database and consolidates the results. The efficiency of the system is demonstrated on several swine feeding scenarios.


Assuntos
Microbioma Gastrointestinal , Interface Usuário-Computador , Animais , Suínos , Bases de Dados Factuais , Fonte de Informação , Semântica
14.
J Appl Microbiol ; 135(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38268415

RESUMO

AIMS: This study aimed to improve the production of mutantioxidin, an antioxidant encoded by a biosynthetic gene cluster (mao) in Streptococcus mutans UA140, through a series of optimization methods. METHOD AND RESULTS: Through the construction of mao knockout strain S. mutans UA140∆mao, we identified mutantioxidin as the antioxidant encoded by mao and verified its antioxidant activity through a reactive oxygen species (ROS) tolerance assay. By optimizing the culture medium and fermentation time, 72 h of fermentation in chemically defined medium (CDM) medium was determined as the optimal fermentation conditions. Based on two promoters commonly used in Streptococcus (ldhp and xylS1p), eight promoter refactoring strains were constructed, nevertheless all showed impaired antioxidant production. In-frame deletion and complementation experiments demonstrated the positive regulatory role of mao1 and mao2, on mao. Afterward, the mao1 and mao2, overexpression strain S. mutans UA140/pDL278:: mao1mao2, were constructed, in which the production of mutantioxidin was improved significantly. CONCLUSIONS: In this study, through a combination of varied strategies such as optimization of fermentation conditions and overexpression of regulatory genes, production of mutantioxidin was increased by 10.5 times ultimately.


Assuntos
Cárie Dentária , Streptococcus mutans , Humanos , Streptococcus mutans/genética , Antioxidantes , Streptococcus , Regiões Promotoras Genéticas , Monoaminoxidase/genética , Biofilmes , Cárie Dentária/prevenção & controle
15.
BMC Cardiovasc Disord ; 24(1): 119, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38383333

RESUMO

INTRODUCTION: This study evaluates the effectiveness of a combined regimen involving injectable hydrogels for the treatment of experimental myocardial infarction. PATIENT CONCERNS: Myocardial infarction is an acute illness that negatively affects quality of life and increases mortality rates. Experimental models of myocardial infarction can aid in disease research by allowing for the development of therapies that effectively manage disease progression and promote tissue repair. DIAGNOSIS: Experimental animal models of myocardial infarction were established using the ligation method on the anterior descending branch of the left coronary artery (LAD). INTERVENTIONS: The efficacy of intracardiac injection of hydrogels, combined with cells, drugs, cytokines, extracellular vesicles, or nucleic acid therapies, was evaluated to assess the functional and morphological improvements in the post-infarction heart achieved through the combined hydrogel regimen. OUTCOMES: A literature review was conducted using PubMed, Web of Science, Scopus, and Cochrane databases. A total of 83 papers, including studies on 1332 experimental animals (rats, mice, rabbits, sheep, and pigs), were included in the meta-analysis based on the inclusion and exclusion criteria. The overall effect size observed in the group receiving combined hydrogel therapy, compared to the group receiving hydrogel treatment alone, resulted in an ejection fraction (EF) improvement of 8.87% [95% confidence interval (CI): 7.53, 10.21] and a fractional shortening (FS) improvement of 6.31% [95% CI: 5.94, 6.67] in rat models, while in mice models, the improvements were 16.45% [95% CI: 11.29, 21.61] for EF and 5.68% [95% CI: 5.15, 6.22] for FS. The most significant improvements in EF (rats: MD = 9.63% [95% CI: 4.02, 15.23]; mice: MD = 23.93% [95% CI: 17.52, 30.84]) and FS (rats: MD = 8.55% [95% CI: 2.54, 14.56]; mice: MD = 5.68% [95% CI: 5.15, 6.22]) were observed when extracellular vesicle therapy was used. Although there have been significant results in large animal experiments, the number of studies conducted in this area is limited. CONCLUSION: The present study demonstrates that combining hydrogel with other therapies effectively improves heart function and morphology. Further preclinical research using large animal models is necessary for additional study and validation.


Assuntos
Hidrogéis , Infarto do Miocárdio , Humanos , Ratos , Camundongos , Animais , Suínos , Coelhos , Ovinos , Hidrogéis/uso terapêutico , Qualidade de Vida , Infarto do Miocárdio/tratamento farmacológico , Coração , Injeções
16.
Appl Microbiol Biotechnol ; 108(1): 267, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498053

RESUMO

ADP-activated ß-D-manno-heptoses (ADP-ß-D-manno-heptoses) are precursors for the biosynthesis of the inner core of lipopolysaccharide in Gram-negative bacteria. Recently, ADP-D-glycero-ß-D-manno-heptose (ADP-D,D-manno-heptose) and its C-6'' epimer, ADP-L-glycero-ß-D-manno-heptose (ADP-L,D-manno-heptose), were identified as potent pathogen-associated molecular patterns (PAMPs) that can trigger robust innate immune responses. Although the production of ADP-D,D-manno-heptose has been studied in several different pathogenic Gram-negative bacteria, current knowledge of ADP-ß-D-manno-heptose biosynthesis in Vibrio strains remains limited. Here, we characterized the biosynthetic enzymes of ADP-D,D-manno-heptose and the epimerase that converts it to ADP-L,D-manno-heptose from Vibrio cholerae (the causative agent of pandemic cholera) and Vibrio parahaemolyticus (non-cholera pathogen causing vibriosis with clinical manifestations of gastroenteritis and wound infections) in comparison with their isozymes from Escherichia coli. Moreover, we discovered that ß-D-mannose 1-phosphate, but not α-D-mannose 1-phosphate, could be activated to its ADP form by the nucleotidyltransferase domains of bifunctional kinase/nucleotidyltransferases HldEVC (from V. cholerae) and HldEVP (from V. parahaemolyticus). Kinetic analyses of the nucleotidyltransferase domains of HldEVC and HldEVP together with the E. coli-derived HldEEC were thus carried out using ß-D-mannose 1-phosphate as a mimic sugar substrate. Overall, our works suggest that V. cholerae and V. parahaemolyticus are capable of synthesizing ADP-ß-D-manno-heptoses and lay a foundation for further physiological function explorations on manno-heptose metabolism in Vibrio strains. KEY POINTS: • Vibrio strains adopt the same biosynthetic pathway as E. coli in synthesizing ADP-ß-D-manno-heptoses. • HldEs from two Vibrio strains and E. coli could activate ß-D-mannose 1-phosphate to ADP-ß-D-mannose. • Comparable nucleotidyltransfer efficiencies were observed in the kinetic studies of HldEs.


Assuntos
Escherichia coli , Vibrio , Escherichia coli/genética , Cinética , Vibrio/genética , Imunidade Inata , Nucleotidiltransferases
17.
J Sci Food Agric ; 104(3): 1668-1678, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37847204

RESUMO

BACKGROUND: Hemp protein isolates (HPIs), which provide a well-balanced profile of essential amino acids comparable to other high-quality proteins, have recently garnered significant attention. However, the underutilized functional attributes of HPIs have constrained their potential commercial applications within the food and agriculture field. This study advocates the utilization of dynamic-high-pressure-microfluidization (DHPM) for the production of stable high-internal-phase emulsions (HIPEs), offering an efficient approach to fully exploit the potential of HPI resources. RESULTS: The findings underscore the effectiveness of DHPM in producing HPI as a stabilizing agent for HIPEs with augmented antioxidant activity. Microfluidized HPI exhibited consistent adsorption and anchoring at the oil-water interface, resulting in the formation of a dense and compact layer. Concurrently, the compression of droplets within HIPEs gave rise to a polyhedral framework, conferring viscoelastic properties and a quasi-solid behavior to the emulsion. Remarkably, HIPEs stabilized by microfluidized HPI demonstrated superior oxidative and storage stability, attributable to the establishment of an antioxidative barrier by microfluidized HPI particles. CONCLUSION: This study presents an appealing approach for transforming liquid oils into solid-like fats using HPI particles, all without the need for surfactants. HIPEs stabilized by microfluidized HPI particles hold promise as emerging food ingredients for the development of emulsion-based formulations with enhanced oxidative stability, thereby finding application in the food and agricultural industries. © 2023 Society of Chemical Industry.


Assuntos
Cannabis , Emulsões/química , Excipientes , Oxirredução , Antioxidantes/metabolismo , Estresse Oxidativo , Tamanho da Partícula
18.
J Ment Health ; : 1-12, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014933

RESUMO

BACKGROUND: Soteria houses and peer respites, collectively called Healing Houses, are alternatives to psychiatric hospitalisation. AIMS: The aim of this research is to review Healing Houses in relation to design characteristics (architectural and service), sustainability and development opportunities and barriers. METHODS: This systematic review followed a PROSPERO protocol (CRD42022378089). Articles were identified from journal database searches, hand searching websites, Google Scholar searches, expert consultation and backwards and forward citation searches. RESULTS: Eight hundred and forty-nine documents were screened in three languages (English, German and Hebrew) and 45 documents were included from seven countries. The review highlights 11 architectural design characteristics (atmosphere, size, soft room, history, location, outdoor space, cleanliness, interior design, facilities, staff only areas and accessibility), six service design characteristics (guiding principles, living and working together, consensual treatment, staff, supporting personal meaning making and power), five opportunities (outcomes, human rights, economics, hospitalization and underserved) and four types of barriers (clinical, economic and regulatory, societal and ideological). The primary sustainability issue was long-term funding. CONCLUSION: Future research should focus on operationalizing a "home-like" atmosphere and the impact of design features such as green spaces on wellbeing of staff and service users. Future research could also produce design guidelines for Healing Houses.

19.
J Am Chem Soc ; 145(25): 13858-13868, 2023 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-37329284

RESUMO

Molecular tessellation research aims to elucidate the underlying principles that govern intricate patterns in nature and to leverage these principles to create precise and ordered structures across multiple scales, thereby facilitating the emergence of novel functionalities. DNA origami nanostructures are excellent building blocks for constructing tessellation patterns. However, the size and complexity of DNA origami tessellation systems are currently limited by several unexplored factors relevant to the accuracy of essential design parameters, the applicability of design strategies, and the compatibility between different tiles. Here, we present a general method for creating DNA origami tiles that grow into tessellation patterns with micrometer-scale order and nanometer-scale precision. Interhelical distance (D) was identified as a critical design parameter determining tile conformation and tessellation outcome. Finely tuned D facilitated the accurate geometric design of monomer tiles with minimized curvature and improved tessellation capability, enabling the formation of single-crystalline lattices ranging from tens to hundreds of square micrometers. The general applicability of the design method was demonstrated by 9 tile geometries, 15 unique tile designs, and 12 tessellation patterns covering Platonic, Laves, and Archimedean tilings. Particularly, we took two strategies to increase the complexity of DNA origami tessellation, including reducing the symmetry of monomer tiles and coassembling tiles of different geometries. Both yielded various tiling patterns that rivaled Platonic tilings in size and quality, indicating the robustness of the optimized tessellation system. This study will promote DNA-templated, programmable molecular and material patterning and open up new opportunities for applications in metamaterial engineering, nanoelectronics, and nanolithography.


Assuntos
DNA , Nanoestruturas , DNA/química , Nanoestruturas/química , Conformação de Ácido Nucleico , Replicação do DNA , Nanotecnologia/métodos
20.
J Neurochem ; 167(4): 489-504, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37823326

RESUMO

Chronic cerebral hypoperfusion leads to sustained demyelination and a unique response of microglia. Triggering receptor expressed on myeloid cells 2 (Trem2), which is expressed exclusively on microglia in the central nervous system (CNS), plays an essential role in microglial response in various CNS disorders. However, the specific role of Trem2 in chronic cerebral hypoperfusion has not been elucidated. In this study, we investigated the specific role of Trem2 in a mouse model of chronic cerebral hypoperfusion induced by bilateral carotid artery stenosis (BCAS). Our results showed that chronic hypoperfusion induced white matter demyelination, microglial phagocytosis, and activation of the microglial autophagic-lysosomal pathway, accompanied by an increase in Trem2 expression. After Trem2 knockout, we observed attenuation of white matter lesions and microglial response. Trem2 deficiency also suppressed microglial phagocytosis and relieved activation of the autophagic-lysosomal pathway, leading to microglial polarization towards anti-inflammatory and homeostatic phenotypes. Furthermore, Trem2 knockout inhibited lipid droplet accumulation in microglia in vitro. Collectively, these findings suggest that Trem2 deficiency ameliorated microglial phagocytosis and autophagic-lysosomal activation in hypoperfusion-induced white matter injury, and could be a promising target for the treatment of chronic cerebral hypoperfusion.


Assuntos
Isquemia Encefálica , Doenças Desmielinizantes , Substância Branca , Animais , Camundongos , Substância Branca/patologia , Microglia/metabolismo , Fagocitose , Isquemia Encefálica/metabolismo , Lisossomos/metabolismo , Doenças Desmielinizantes/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo
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