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1.
J Ethnopharmacol ; 323: 117609, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38142875

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: In elderly people, Alzheimer's disease (AD) is the most common form of dementia. It has been shown that traditional Chinese medicine (TCM) based on phytomedicines enhances the therapeutic effects of modern medicine when taken in conjunction with them. Modern medicine N-methyl-D-aspartate receptor (NMDA) antagonist memantine (Mm) are mainly used in the clinical treatment of AD. TCM Cerebralcare Granule® (CG) has long been an effective treatment for headaches, dizziness, and other symptoms. In this study, we employ a blend of CG and Mm to address Alzheimer's disease-like symptoms and explore their impacts and underlying mechanisms. AIM OF THE STUDY: The objective of our study was to observe the effects of CG combined with Memantine (Mm) on learning and memory impairment of AD mice induced by D-galactose and to explore the mechanism at work. MATERIALS AND METHODS: CG and Mm were combined to target multiple pathological processes involved in AD. For a thorough analysis, we performed various experiments such as behavioral detection, pathological detection, proteomic detection, and other experimental methods of detection. RESULTS: It was found that the combination of CG and Mm was significantly effective for improving learning and memory in AD mice as well as brain pathology. The serum and hippocampal tissue of AD mice were significantly enhanced with catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) levels were decreased with this treatment. In AD mice, a combination of Mm and CG (CG + Mm) significantly increased the levels of the anti-inflammatory factors IL-4 and IL-10, decreased the levels of pro-inflammatory factors (IL-6, IL-1ß) and tumor necrosis factor-alpha (TNF-α), improved synaptic plasticity by restoring synaptophysin (SYP) and postsynaptic density protein-95 (PSD-95) expression in the hippocampus, enhanced Aß phagocytosis of microglia in AD mice, and increased mitochondrial respiratory chain enzyme complexes I, II, III, and IV, lead to an increase in the number of functionally active NMDA receptors in the hippocampus. Proteomic analysis GO analysis showed that the positive regulation gene H3BIV5 of G protein coupled receptor signal pathway and synaptic transmission was up-regulated, while the transsynaptic signal of postsynaptic membrane potential and regulation-related gene Q5NCT9 were down-regulated. Most proteins showed significant enriched signal transduction pathway profiles after CG + Mm treatment, based on the KEGG pathway database. CONCLUSION: The data supported the idea that CG and Mm could be more effective in treating AD mice induced by D-galactose than Mm alone. We provided a basis for the clinical use of CG with Mm.


Assuntos
Doença de Alzheimer , Humanos , Camundongos , Animais , Idoso , Doença de Alzheimer/metabolismo , Memantina/efeitos adversos , Galactose , Proteômica , Hipocampo , Antioxidantes/farmacologia
2.
J Chem Phys ; 158(23)2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37318176

RESUMO

In this work, the dynamics of a prototypical heavy-light-heavy abstract reaction, Cl(2P) + HCl → HCl + Cl(2P), is investigated both by constructing a new potential energy surface (PES) and by rate coefficient calculations. Both the permutation invariant polynomial neural network method and the embedded atom neural network (EANN) method, based on ab initio MRCI-F12+Q/AVTZ level points, are used for obtaining globally accurate full-dimensional ground state PES, with the corresponding total root mean square error being only 0.043 and 0.056 kcal/mol, respectively. In addition, this is also the first application of the EANN in a gas-phase bimolecular reaction. The saddle point of this reaction system is confirmed to be nonlinear. In comparison with both the energetics and rate coefficients obtained on both PESs, we find that the EANN is reliable in dynamic calculations. A full-dimensional approximate quantum mechanical method, ring-polymer molecular dynamics with a Cayley propagator, is employed to obtain the thermal rate coefficients and kinetic isotopic effects of the title reaction Cl(2P) + XCl→ XCl + Cl(2P) (H, D, Mu) on both new PESs, and the kinetic isotope effect (KIE) is also obtained. The rate coefficients reproduce the experimental results at high temperatures perfectly but with moderate accuracy at lower temperatures, but the KIE is with high accuracy. The similar kinetic behavior is supported by quantum dynamics using wave packet calculations as well.

3.
Phytomedicine ; 109: 154600, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36610144

RESUMO

BACKGROUND: There is no doubt that Alzheimer's disease (AD) is one of the greatest threats facing mankind today. Within the next few decades, Acetylcholinesterase inhibitors (AChEIs) will be the most widely used treatment for Alzheimer's disease. The withdrawal of the first generation AChEIs drug Tacrine (TAC)/ Cognex from the market as a result of hepatotoxicity has always been an interesting case study. Rosmarinic acid (RA) is a natural compound of phenolic acids that has pharmacological activity for inhibiting Alzheimer's disease, as well as liver protection. PURPOSE AND STUDY DESIGN: In this study, we determined that RA can reduce the hepatotoxicity of TAC, and both of them act synergistically to inhibit the progression of AD in mice. METHODS: In addition to the wild type mice (WT) group, the 6-month-old APP/PS1 (APPswe/PSEN1dE9) double-transgenic (Tg) mice were randomly divided into 6 groups: Tg group, TAC group, RA group, TAC+Silymarin (SIL) group, TAC+RA-L (Rosmarinic Acid Low Dose) goup and TAC+RA-H (Rosmarinic Acid High Dose) group. A series of experiments were carried out, including open field test, Morris water maze test, Hematoxylin - Eosin (HE) staining, Nissl staining, biochemical analysis, immunofluorescence analysis, western blotting analysis and so on. RESULTS: RA combined with TAC could enter the brain tissue of AD mice, and the combination of drugs could better improve the cognitive behavior and brain pathological damage of AD mice, reduce the expression of A ß oligomer, inhibit the deposition of A ß, inhibit the activity of AChE and enhance the level of Ach in hippocampus. Both in vivo and in vitro experiments showed that RA could alleviate the hepatotoxicity or liver injury induced by TAC. The Western blot analysis of the liver of AD mice showed that RA combined with TAC might inhibit the apoptosis of Bcl-2/Bax, reduce the programmed apoptosis mediated by caspase-3 and reduce the burden of liver induced by TAC, could inhibit the development of liver apoptosis by alleviating the hepatotoxicity of TAC and inhibiting the phosphorylation of JNK. CONCLUSION: The potential drug combination that combines rosmarinic acid with tacrine could reduce tacrine's hepatotoxicity as well as enhance its therapeutic effect on Alzheimer's disease.


Assuntos
Doença de Alzheimer , Doença Hepática Induzida por Substâncias e Drogas , Camundongos , Animais , Doença de Alzheimer/metabolismo , Tacrina/farmacologia , Tacrina/uso terapêutico , Acetilcolinesterase/metabolismo , Camundongos Transgênicos , Modelos Animais de Doenças , Peptídeos beta-Amiloides , Ácido Rosmarínico
4.
J Chem Phys ; 157(22): 224302, 2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36546819

RESUMO

The mode selectivity in the prototypical H + CH3D reaction is investigated by the initial state selected time-dependent wave packet method within a ten-dimensional quantum dynamics model. The model is a novel reduced dimensional model for the X + YCZ3 reaction, which allows the CZ3 to break C3V symmetry. The calculated reaction probabilities initially from different reactant vibrational states show that the CH3 stretching modes excitations obviously promote the H-abstraction reaction but have a slight influence on the D-abstraction reaction. In contrast, the CD stretching mode excitation significantly enhances the D-abstraction reaction. For both H- and D-abstraction reactions, the excitation of either the CH3 umbrella bending mode or the CH3 rocking mode shows a promotional effect on the reactivity, while fundamental excitation of the CH3 bending mode has a negligible effect. Impressively, the first-overtone excitation of CH3 bending mode remarkably promotes the H-abstraction reaction, resulting from the 1:2 Fermi coupling between the CH3 symmetric stretching mode and the first overtone of CH3 bending mode. In addition, translational energy is more efficient than vibrational energy in promoting the H-abstraction reaction at low energy, while vibrational energy becomes more efficient for the D-abstraction reaction.

5.
J Nanobiotechnology ; 20(1): 485, 2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402976

RESUMO

Currently, tumor treatments are characterized by intelligence, diversity and personalization, but the therapeutic reagents used are often limited in clinical efficacy due to problems with water solubility, targeting, stability and multidrug resistance. To remedy these shortcomings, the application of multifunctional nanotechnology in the biomedical field has been widely studied. Synthetic melanin nanoparticles (MNPs) surfaces which contain highly reactive chemical groups such as carboxyl, hydroxyl and amine groups, can be used as a reaction platform on which to graft different functional components. In addition, MNPs easily adhere to substrate surface, and serve as a secondary reaction platform to modify it. The multifunctionality and intrinsic biocompatibility make melanin-like nanoparticles promising as a multifunctional and powerful nanoplatform for oncological applications. This paper first reviews the preparation methods, polymerization mechanisms and physicochemical properties of melanin including natural melanin and chemically synthesized melanin to guide scholars in MNP-based design. Then, recent advances in MNPs especially synthetic polydopamine (PDA) melanin for various medical oncological applications are systematically and thoroughly described, mainly focusing on bioimaging, photothermal therapy (PTT), and drug delivery for tumor therapy. Finally, based on the investigated literature, the current challenges and future directions for clinical translation are reasonably discussed, focusing on the innovative design of MNPs and further elucidation of pharmacokinetics. This paper is a timely and comprehensive and detailed study of the progress of MNPs in tumor therapy, especially PTT, and provides ideas for the design of personalized and customizable oncology nanomedicines to address the heterogeneity of the tumor microenvironment.


Assuntos
Nanopartículas , Neoplasias , Humanos , Melaninas/química , Terapia Fototérmica , Nanopartículas/uso terapêutico , Nanopartículas/química , Nanomedicina , Neoplasias/tratamento farmacológico , Microambiente Tumoral
6.
Nat Commun ; 13(1): 7365, 2022 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-36450777

RESUMO

Antimicrobial resistance of Shigella sonnei has become a global concern. Here, we report a phylogenetic group of S. sonnei with extensive drug resistance, including a combination of multidrug resistance, coresistance to ceftriaxone and azithromycin (cefRaziR), reduced susceptibility to fluoroquinolones, and even colistin resistance (colR). This distinct clone caused six waterborne shigellosis outbreaks in China from 2015 to 2020. We collect 155 outbreak isolates and 152 sporadic isolates. The cefRaziR isolates, including outbreak strains, are mainly distributed in a distinct clade located in global Lineage III. The outbreak strains form a recently derived monophyletic group that may have emerged circa 2010. The cefRaziR and colR phenotypes are attributed to the acquisition of different plasmids, particularly the IncB/O/K/Z plasmid coharboring the blaCTX-M-14, mphA, aac(3)-IId, dfrA17, aadA5, and sul1 genes and the IncI2 plasmid with an mcr-1 gene. Genetic analyses identify 92 accessory genes and 60 single-nucleotide polymorphisms associated with the cefRaziR phenotype. Surveillance of this clone is required to determine its dissemination and threat to global public health.


Assuntos
Surtos de Doenças , Shigella sonnei , Shigella sonnei/genética , Filogenia , China/epidemiologia , Fluoroquinolonas , Resistência a Medicamentos , Células Clonais
7.
Risk Anal ; 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100578

RESUMO

The Grunow-Finke epidemiological assessment tool (GFT) has several limitations in its ability to differentiate between natural and man-made epidemics. Our study aimed to improve the GFT and analyze historical epidemics to validate the model. Using a gray relational analysis (GRA), we improved the GFT by revising the existing standards and adding five new standards. We then removed the artificial weights and final decision threshold. Finally, by using typically unnatural epidemic events as references, we used the GRA to calculate the unnatural probability and obtain assessment results. Using the advanced tool, we conducted retrospective and case analyses to test its performance. In the validation set of 13 historical epidemics, unnatural and natural epidemics were divided into two categories near the unnatural probability of 45%, showing evident differences (p < 0.01) and an assessment accuracy close to 100%. The unnatural probabilities of the Ebola virus disease of 2013 and Middle East Respiratory Syndrome of 2012 were 30.6% and 36.1%, respectively. Our advanced epidemic assessment tool improved the accuracy of the original GFT from approximately 55% to approximately 100% and reduced the impact of human factors on these outcomes effectively.

8.
Infect Dis Model ; 7(2): 117-126, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35475256

RESUMO

Numerous studies have proposed search engine-based estimation of COVID-19 prevalence during the COVID-19 pandemic; however, their estimation models do not consider the impact of various urban socioeconomic indicators (USIs). This study quantitatively analysed the impact of various USIs on search engine-based estimation of COVID-19 prevalence using 15 USIs (including total population, gross regional product (GRP), and population density) from 369 cities in China. The results suggested that 13 USIs affected either the correlation (SC-corr) or time lag (SC-lag) between search engine query volume and new COVID-19 cases ( p <0.05). Total population and GRP impacted SC-corr considerably, with their correlation coefficients r for SC-corr being 0.65 and 0.59, respectively. Total population, GRP per capita, and proportion of the population with a high school diploma or higher had simultaneous positive impacts on SC-corr and SC-lag ( p <0.05); these three indicators explained 37-50% of the total variation in SC-corr and SC-lag. Estimations for different urban agglomerations revealed that the goodness of fit, R 2 , for search engine-based estimation was more than 0.6 only when total urban population, GRP per capita, and proportion of the population with a high school diploma or higher exceeded 11.08 million, 120,700, and 38.13%, respectively. A greater urban size indicated higher accuracy of search engine-based estimation of COVID-19 prevalence. Therefore, the accuracy and time lag for search engine-based estimation of infectious disease prevalence can be improved only when the total urban population, GRP per capita, and proportion of the population with a high school diploma or higher are greater than the aforementioned thresholds.

11.
Front Microbiol ; 12: 779749, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34880847

RESUMO

Salmonella contamination of eggs and egg shells has been identified as a public health problem worldwide. Here, we reported an outbreak of severe gastrointestinal symptoms caused by Salmonella enterica serovar Enteritidis (S. enteritidis) in China. We evaluated the outbreak by using epidemiological surveys, routine laboratory testing methods, and whole genome sequencing (WGS). This outbreak occurred in a canteen in Beijing, during March 9-11, 2021, 225 of the 324 diners who have eaten at the canteen showed gastrointestinal symptoms. The outbreak had characteristical epidemiological and clinical features. It caused a very high attack rate (69.4%) in a short incubation time. All patients developed diarrhea and high fever, accompanied by abdominal pain (62.3%), nausea (50.4%), and vomiting (62.7%). The average frequency of diarrhea was 12.4 times/day, and the highest frequency of diarrhea was as high as 50 times/day. The average fever temperature was 39.4°C, and the highest fever temperature was 42°C. Twenty strains of S. enteritidis were recovered, including 19 from the patients samples, and one from remained egg fried rice. Antibiotic susceptibility test showed that the 20 outbreak strains all had the same resistance pattern. PFGE results demonstrated that all 20 strains bore completely identical bands. Phylogenetic analysis based on WGS revealed that all 20 outbreak strains were tightly clustered together. So the pathogenic source of this food poisoning incident may was contaminated egg fried rice. Resistance gene analysis showed that the outbreak strains are all multi-drug resistant strains. Virulence gene analysis indicated that these outbreak strains carried a large number of virulence genes, including 2 types of Salmonella pathogenicity islands (SPI-1 and SPI-2). Other important virulence genes were also carried by the outbreak strains, such as pefABCD, rck and shdA. And the shdA gene was not in other strains located in the same evolutionary branch as the outbreak strain. We speculated that this is a significant reason for the serious symptoms of gastroenteritis in this outbreak. This outbreak caused by S. enteritidis suggested government should strengthen monitoring of the prevalence of outbreak clone strains, and take measures to mitigate the public health threat posed by contaminated eggs.

12.
IBRO Neurosci Rep ; 11: 164-174, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34746914

RESUMO

Exercise can reduce the incidence of stress-related mental diseases, such as depression and anxiety. Control group was neither exposed to CVMS nor TRE (noCVMS/noTRE). Females were tested and levels of serum17-beta-oestradiol (E2), estrogen receptors α immunoreactive neurons (ERα-IRs), estrogen receptors ß immunoreactive neurons (ERß-IRs) and oxytocin immunoreactive neurons (OT-IRs) were measured. The results showed there's increased anxiety-like behaviors for mice from CVMS/noTRE, CVMS/higher speed TRE (CVMS/HTRE) and noCVMS/HTRE groups when they were put in open field and elevated maze tests. They had lower serum E2 levels than mice from CVMS/low-moderate speed TRE (CVMS/LMTRE), noCVMS/LMTRE and noCVMS/noTRE groups. The three groups of CVMS/noTRE, CVMS/HTRE and noCVMS/HTRE mice had more ERα-IRs and less ERß-IRs in the medial preoptic area (mPOA), bed nucleus of the stria terminalis (BNST) and medial amygdala (MeA), hypothalamic paraventricular nucleus (PVN) and supraoptic nucleus (SON). The number of OT-IRs in PVN and SON of CVMS/noTRE, CVMS/HTRE and noCVMS/HTRE mice was also lower than that of mice from CVMS/LMTRE, noCVMS/LMTRE and noCVMS/noTRE groups. Interestingly, CVMS/LMTRE and noCVMS/LMTRE mice were similar to noCVMS/noTRE mice in that they did not show anxiety, while CVMS/HTRE and noCVMS/HTRE mice did not, which were similar to the mice in CVMS/noTRE. We propose that LMTRE instead of HTRE changes the serum concentration of E2. ERß/ERα ratio and OT level in the brain may be responsible for the decrease in anxiety-like behavior in female mice exposed to anxiety-inducing stress conditions.

13.
Front Med (Lausanne) ; 8: 735779, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34650998

RESUMO

Objectives: To data, no patients with obvious epidemiological relationship co-infected with SARS-CoV-2 and other pathogens have been reported. Here, we investigated 10 patients caused by co-infection with SARS-CoV-2 and human adenovirus (HAdV), resulting in third-generation transmission. Materials and Methods: From Jan 15, 2020, we enrolled 10 patients with pneumonia in Hunan Province, China. Epidemiological, clinical, and laboratory investigation results from these patients were analyzed. An epidemiological investigation was performed to assess whether patient infections were linked using conventional methods and metagenomic sequencing. Results: The presence of co-infection with SARS-CoV-2 and HAdV was determined via RT-PCR and metagenomic sequencing. Phylogenetic analysis revealed that SARS-CoV-2 and HAdV genomes clustered together, with similar genetic relationships. The first patient likely became co-infected during meetings or travel in Wuhan. The patient transmitted the virus via dinners and meetings, which resulted in four second-generation cases. Then, a second-generation case transmitted the virus to her family members or relatives via presymptomatic transmission. Conclusions: This study described an example of co-infection with SARS-CoV-2 and HAdV in pneumonia patients, which caused third-generation cases and inter-regional transmission via meetings, household interactions, and dinner parties. We also observed the persistent and presymptomatic transmission of co-infection, which has the potential to make the continued control of the COVID-19 pandemic challenging. Continuous surveillance is needed to monitor the prevalence, infectivity, transmissibility, and pathogenicity of SARS-CoV-2 co-infection with other pathogens to evaluate its real risk.

14.
Front Microbiol ; 12: 774797, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35082765

RESUMO

With the rapid emergence of plasmid-mediated colistin resistance gene mcr-1, the increased resistance of Salmonella has attracted extensive attention. This study reports on 11 multidrug-resistant Salmonella enterica serovar Typhimurium strains harboring mcr-1 in China. They all presented resistance to colistin, and additionally, one that was isolated from a child's stool sample was also resistant to ceftriaxone and azithromycin. We screened 1454 strains of Salmonella for mcr-1 gene through PCR, and these strains are all preserved in our laboratory. Antimicrobial sensitivity analysis was carried out for the screened mcr-1 positive strains. Genetic polymorphism analysis of S. Typhimurium was performed by using the Pulsed-Field Gel Electrophoresis (PFGE). The plasmids harboring mcr-1 were identified by S1-PFGE and southern blotting. Plasmid conjugation assays were used to analyze the transferability of colistin resistance. The plasmids harboring mcr-1 were characterized by sequencing and bioinformatic analysis. Eleven S. Typhimurium strains harboring mcr-1 with colistin resistance (MICs 4µg/ml) were detected, which were isolated from children and pig offal in China. All of them were multidrug-resistant strains. PFGE results revealed that the strains isolated from different samples or locations have identical genotypes. S1-PFGE and southern blotting experiments showed that three plasmids of different sizes (33, 60, and 250 kb) all carried the mcr-1 gene. The plasmid conjugation assays revealed that Salmonella acquired mcr-1 harboring plasmids by horizontal transfer. Sequencing and plasmid type analysis revealed that these plasmids were types IncX4, IncI2, and IncHI2. Among them, IncX4 and IncI2 plasmids had extremely similar backbones and contained one resistant gene mcr-1. IncHI2 plasmid contained multiple resistant genes including bla CTX-M, oqxB, sul, aph, aadA, and bla TEM. We identified 11 mcr-1 harboring S. Typhimurium strains in China and described their characteristics. Our findings indicate that the mcr-1 gene can effectively spread among intestinal bacteria by horizontal transfer of three types of plasmids. Moreover, the IncHI2 plasmid can also mediate the transfer of other drug resistance genes. These results reveal that constant surveillance of mcr-1 harboring S Typhimurium is imperative to prevent the spread of colistin resistance.

15.
Mol Cell ; 80(4): 607-620.e12, 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-33113344

RESUMO

Aberrant mitophagy has been implicated in a broad spectrum of disorders. PINK1, Parkin, and ubiquitin have pivotal roles in priming mitophagy. However, the entire regulatory landscape and the precise control mechanisms of mitophagy remain to be elucidated. Here, we uncover fundamental mitophagy regulation involving PINK1 and a non-canonical role of the mitochondrial Tu translation elongation factor (TUFm). The mitochondrion-cytosol dual-localized TUFm interacts with PINK1 biochemically and genetically, which is an evolutionarily conserved Parkin-independent route toward mitophagy. A PINK1-dependent TUFm phosphoswitch at Ser222 determines conversion from activating to suppressing mitophagy. PINK1 modulates differential translocation of TUFm because p-S222-TUFm is restricted predominantly to the cytosol, where it inhibits mitophagy by impeding Atg5-Atg12 formation. The self-antagonizing feature of PINK1/TUFm is critical for the robustness of mitophagy regulation, achieved by the unique kinetic parameters of p-S222-TUFm, p-S65-ubiquitin, and their common kinase PINK1. Our findings provide new mechanistic insights into mitophagy and mitophagy-associated disorders.


Assuntos
Drosophila melanogaster/crescimento & desenvolvimento , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Mitofagia , Fator Tu de Elongação de Peptídeos/metabolismo , Proteínas Quinases/metabolismo , Animais , Citosol/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Células HeLa , Humanos , Masculino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Fator Tu de Elongação de Peptídeos/genética , Fosforilação , Domínios e Motivos de Interação entre Proteínas , Proteínas Quinases/genética , Transporte Proteico , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-33042862

RESUMO

Regulation of the environmental stress response and virulence of Shigella flexneri may involve multiple signaling pathways; however, these mechanisms are not well-defined. In bacteria, small regulatory RNAs (sRNAs) regulate bacterial growth, metabolism, virulence, and environmental stress response. Therefore, identifying novel functional sRNAs in S. flexneri could help elucidate pathogenic adaptations to host micro-environmental stresses and associated virulence. The aim of this study was to confirm the presence of an sRNA, Ssr54, in S. flexneri and to determine its functions and possible mechanism of action. Ssr54 was found to regulate tolerance and virulence under hyperosmotic pressure. Its expression was verified by qRT-PCR and Northern blotting, and its genomic position was confirmed by 5'-rapid amplification of cDNA ends. Ssr54 expression was significantly decreased (~ 80%) under hyperosmotic conditions (680 mM NaCl), and the survival rate of the Ssr54 deletion strain increased by 20% under these conditions. This suggested that Ssr54 has been selected to promote host survival under hyperosmotic conditions. Additionally, virulence assessment, including guinea pig Sereny test and competitive invasion assays in mouse lungs, revealed that Ssr54 deletion significantly decreased S. flexneri virulence. Two-dimensional gel analyses suggest that Ssr54 may modulate the expression of tolC, ompA, and treF genes, which may affect the virulence and survival of S. flexneri under osmotic pressures. Furthermore, treF expression has been shown to improve the survival of S. flexneri under osmotic pressures. These results suggest that Ssr54 has a broad range of action in S. flexneri response to hyperosmotic environmental stresses and in controlling its virulence to adapt to environmental stresses encountered during host infection.


Assuntos
Regulação Bacteriana da Expressão Gênica , Shigella flexneri , Animais , Proteínas de Bactérias/genética , Cobaias , Camundongos , Shigella flexneri/genética , Shigella flexneri/metabolismo , Estresse Fisiológico , Virulência
17.
Aging Cell ; 19(9): e13210, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32749068

RESUMO

How complex interactions of genetic, environmental factors and aging jointly contribute to dopaminergic degeneration in Parkinson's disease (PD) is largely unclear. Here, we applied frequent gene co-expression analysis on human patient substantia nigra-specific microarray datasets to identify potential novel disease-related genes. In vivo Drosophila studies validated two of 32 candidate genes, a chromatin-remodeling factor SMARCA4 and a biliverdin reductase BLVRA. Inhibition of SMARCA4 was able to prevent aging-dependent dopaminergic degeneration not only caused by overexpression of BLVRA but also in four most common Drosophila PD models. Furthermore, down-regulation of SMARCA4 specifically in the dopaminergic neurons prevented shortening of life span caused by α-synuclein and LRRK2. Mechanistically, aberrant SMARCA4 and BLVRA converged on elevated ERK-ETS activity, attenuation of which by either genetic or pharmacological manipulation effectively suppressed dopaminergic degeneration in Drosophila in vivo. Down-regulation of SMARCA4 or drug inhibition of MEK/ERK also mitigated mitochondrial defects in PINK1 (a PD-associated gene)-deficient human cells. Our findings underscore the important role of epigenetic regulators and implicate a common signaling axis for therapeutic intervention in normal aging and a broad range of age-related disorders including PD.


Assuntos
DNA Helicases/genética , Neurônios Dopaminérgicos/fisiologia , Epigênese Genética/genética , Sistema de Sinalização das MAP Quinases/genética , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Idoso , Envelhecimento , Animais , Modelos Animais de Doenças , Humanos
19.
Life Sci ; 239: 117052, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31733318

RESUMO

AIMS: A combination of biomarker and instrument technology diagnosis methods, especially antigen-targeted imaging methods, is required to increase the accuracy of the diagnosis of cancer. Currently, the targeting efficiency is limited by the conjugation methods used for the conjugation of antibodies and imaging materials. Here, a simple strategy for the conjugation of a probe and a single-chain fragment antibody (scFv) that does not change the characteristics of the antibody was shown. MAIN METHODS: An ScFv was conjugated with superparamagnetic iron oxide (SPIO) or indocyanine green (ICG) via a linker by utilizing the reaction between cysteine and maleimide. The characterization of the probe was performed by flow cytometry, confocal imaging, optical imaging and magnetic resonance imaging (MRI). KEY FINDINGS: After conjugation, the scFv retained high affinity, antigen specificity, and strong internalization ability. The application of the conjugated probe was also confirmed by optical imaging and MRI. SIGNIFICANCE: The proposed strategy provides a simple method for the production of high efficiency antigen-targeted imaging probes for tumor diagnosis.


Assuntos
Anticorpos Monoclonais/química , Imageamento por Ressonância Magnética/métodos , Anticorpos de Cadeia Única/química , Anticorpos Monoclonais/metabolismo , Linhagem Celular Tumoral , Meios de Contraste , Compostos Férricos/química , Citometria de Fluxo , Humanos , Verde de Indocianina/química , Nanopartículas de Magnetita , Anticorpos de Cadeia Única/metabolismo
20.
Mol Biol Rep ; 46(2): 2493-2504, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30919211

RESUMO

Osteoarthritis (OA) is a degenerative joint disease, in which low-grade inflammation plays an important role at the initiating step. Low-doses of LPS-induced inflammation in the plasma activate chondrocytes and promote the secretion proinflammatory cytokines, leading to secondary inflammation. Blocking OA-associated TLR activation is a promising strategy for the development of suitable therapies. Here, we want to find some bacteria-derived peptides that can block TLR signaling in chondrocytes more efficiently. Based on previous studies, we screened 12 TIR domain-derived peptides for their effects on NF-кB activation induced by LPS, IL-1ß or TNF-α in murine ATDC-5 cells. We evaluated their effects on LPS-induced cytokine expression and secretion. Among them, two bacteria-derived peptides, TcpC-DD and TcpB-DD, showed the most potent inhibitory activities. In comparison with TcpB-DD, TcpC-DD exhibited broader TLR-inhibitory specificity during inflammation in chondrocytes. Furthermore, both TcpC-DD and TcpB-DD displayed strong inhibition of LPS- and IL-1ß-induced catabolic reactions in chondrocytes. However, only TcpC-DD exhibited obvious suppression of TNF-α-induced catabolism. In conclusion, we identified two novel inhibitory peptides that modulate catabolism in chondrocytes and innate immune responses, and these peptides could be used to develop novel therapeutic strategies for OA.


Assuntos
Proteínas da Membrana Bacteriana Externa/farmacologia , Condrócitos/imunologia , Imunidade Inata/efeitos dos fármacos , Animais , Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Linhagem Celular , Células Cultivadas , Citocinas/metabolismo , Humanos , Imunidade Inata/imunologia , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Camundongos , NF-kappa B/metabolismo , Osteoartrite/imunologia , Osteoartrite/fisiopatologia , Peptídeos/metabolismo , Domínios Proteicos , Receptores de Interleucina-1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
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