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1.
Biosens Bioelectron ; 259: 116416, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38797033

RESUMO

The low abundance, heterogeneous expression, and temporal changes of miRNA in different cellular locations pose significant challenges for both the detection sensitivity of miRNA liquid biopsy and intracellular imaging. In this work, we report an intelligently assembled biosensor based on catalytic hairpin assembly (CHA) and aggregation-induced emission (AIE), named as catalytic hairpin aggregation-induced emission (CHAIE), for the ultrasensitive detection and intracellular imaging of miRNA-155. To achieve such goal, tetraphenylethylene-N3 (TPE-N3) is used as AIE luminogen (AIEgen), while graphene oxide is introduced to quench the fluorescence. When the target miRNA is present, CHA reaction is triggered, causing the AIEgen to self-assemble with the hairpin DNA. This will restrict the intramolecular rotation of the AIEgen and produce a strong AIE fluorescence. Interestingly, CHAIE does not require any enzyme or expensive thermal cycling equipment, and therefore provides a rapid detection. Under optimal conditions, the proposed biosensor can determine miRNA in the concentration range from 2 pM to 200 nM within 30 min, with the detection limit of 0.42 pM. The proposed CHAIE biosensor in this work offers a low background signal and high sensitivity, making it applicable for highly precise spatiotemporal imaging of target miRNA in living cells.

2.
Talanta ; 276: 126200, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38735243

RESUMO

Herein, a dual-emission Eu metal-organic framework (Eu-MOF) is prepared and used as the ratiometric fluorescence probe for ultrasensitive detection of aminoglycoside antibiotics (AGs). Due to the strong hydrogen bond interactions between AGs and Eu-MOF, the blue emission is enhanced while the red emission has little fluctuation in Eu-MOF with the addition of AGs, thus a good linear relationship with the logarithm of AGs concentrations from 0.001 to 100 µg/mL can be established for quantitative analysis. Good sensitivity with the detection limit of 0.33 ng/mL for apramycin, 0.32 ng/mL for amikacin and 0.30 ng/mL for kanamycin is achieved. The proposed assay demonstrates good selectivity and applicability for determination of AGs in real milk and honey samples. The Eu-MOF materials are further fabricated as fluorescent test papers for facile visual detection. The as-established ratio fluorescence platform offers a portable and economical way for rapid monitoring AGs residues in complex food samples.

3.
Eur J Pharmacol ; 966: 176344, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38280462

RESUMO

Diabetes-associated cognitive dysfunction (DACD) is a complication of diabetes mellitus that leads to an increased risk of cognitive impairment and dementia. However, the molecular mechanism underlying DACD has not been elucidated, and a promising therapy for this disease remains to be established. Hydrogen sulfide (H2S), a significant antioxidative and anti-inflammatory gasotransmitter, has emerged as a neuroprotective agent. In this study, we investigated the protective effects of H2S on DACD in a streptozotocin (STZ)-induced diabetic rat model. We applied the Morris water maze to evaluate spatial learning and memory abilities. We used Western blotting and immunohistochemical staining to investigate the expression of the Nrf-2/HO-1 axis and the NLRP3 inflammasome. After NaHS (H2S donor) administration, diabetic rats exhibited improved spatial learning and memory retrieval abilities in the Morris water maze. In STZ-induced diabetic rats, the protein expression levels of the Nrf-2/HO-1 axis, the NLRP3 inflammasome and subsequent inflammatory cytokines in the hippocampal region were elevated compared to those in control rats. Exogenous H2S triggered Nrf-2/HO-1 antioxidant activity and inhibited NLRP3 inflammasome activation and proinflammatory cytokine expression. These findings suggested that exogenous H2S has neuroprotective effects by modulating the Nrf-2/HO-1 axis and the NLRP3 inflammasome pathway, which were found to be associated with DACD. H2S treatment may be a promising therapeutic strategy for preventing the progression of tissue damage caused by DACD.


Assuntos
Disfunção Cognitiva , Diabetes Mellitus Experimental , Sulfeto de Hidrogênio , Ratos , Animais , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Sulfeto de Hidrogênio/farmacologia , Sulfeto de Hidrogênio/uso terapêutico , Sulfeto de Hidrogênio/metabolismo , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia
4.
Molecules ; 28(22)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38005351

RESUMO

Enterococci resistance is increasing sharply, which poses a serious threat to public health. Rhamnolipids are a kind of amphiphilic compound used for its bioactivities, while the combination of nontraditional drugs to restore linezolid activity is an attractive strategy to treat infections caused by these pathogens. This study aimed to investigate the activity of linezolid in combination with the rhamnolipids against Enterococcus faecium. Here, we determined that the rhamnolipids could enhance the efficacy of linezolid against enterococci infections by a checkerboard MIC assay, a time-kill assay, a combined disk test, an anti-biofilm assay, molecular simulation dynamics, and mouse infection models. We identified that the combination of rhamnolipids and linezolid restored the linezolid sensitivity. Anti-biofilm experiments show that our new scheme can effectively inhibit biofilm generation. The mouse infection model demonstrated that the combination therapy significantly reduced the bacterial load in the feces, colons, and kidneys following subcutaneous administration. This study showed that rhamnolipids could play a synergistic role with linezolid against Enterococcus. Our combined agents could be appealing candidates for developing new combinatorial agents to restore antibiotic efficacy in the treatment of linezolid-resistant Enterococcus infections.


Assuntos
Enterococcus faecium , Animais , Camundongos , Linezolida/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Enterococcus , Testes de Sensibilidade Microbiana , Enterococcus faecalis , Farmacorresistência Bacteriana
5.
Arch Microbiol ; 205(6): 251, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37249701

RESUMO

There is an increasing interest in the use of spore-forming Bacillus spp. as probiotic ingredients on the market. However, probiotics Bacillus species are insufficient, and more safe Bacillus species were required. In the study, traditional fermented foods and soil samples were collected from more than ten provinces in China, and 506 Bacillus were selected from 109 samples. Using the optimized procedure, we screened nine strains, which successfully passed the acid, alkali, bile salt, and trypsin resistance test. Drug sensitivity test results showed that three Bacillus out of the nine isolates exhibited antibiotic sensitivity to more than 29 antibiotics. The three strains sensitive to antibiotics were identified by 16S ribosomal RNA, recA, and gyrB gene analysis, two isolates (38,327 and 38,328) belong to the species Lysinibacillus capsici and one isolate (37,326) belong to Bacillus halotolerans. Moreover, the three strains were confirmed safe through animal experiments. Finally, L. capsici 38,327 and 38,328 showed protections in the Salmonella typhimurium infection mouse model, which slowed down weight loss, reduced bacterial load, and improved antioxidant capacity. Altogether, our data demonstrated that selected L. capsici strains can be used as novel probiotics for intestinal health.


Assuntos
Bacillaceae , Probióticos , Animais , Camundongos , Solo , Antibacterianos/farmacologia , Bacillaceae/genética , Intestinos , RNA Ribossômico 16S/genética
6.
Molecules ; 28(8)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37110837

RESUMO

Disease-related biomarkers may serve as indicators of human disease. The clinical diagnosis of diseases may largely benefit from timely and accurate detection of biomarkers, which has been the subject of extensive investigations. Due to the specificity of antibody and antigen recognition, electrochemical immunosensors can accurately detect multiple disease biomarkers, including proteins, antigens, and enzymes. This review deals with the fundamentals and types of electrochemical immunosensors. The electrochemical immunosensors are developed using three different catalysts: redox couples, typical biological enzymes, and nanomimetic enzymes. This review also focuses on the applications of those immunosensors in the detection of cancer, Alzheimer's disease, novel coronavirus pneumonia and other diseases. Finally, the future trends in electrochemical immunosensors are addressed in terms of achieving lower detection limits, improving electrode modification capabilities and developing composite functional materials.


Assuntos
Técnicas Biossensoriais , COVID-19 , Humanos , Imunoensaio , Técnicas Eletroquímicas , COVID-19/diagnóstico , Biomarcadores
7.
Nat Commun ; 14(1): 1235, 2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36871047

RESUMO

Fibroblast growth factor-18 (FGF18) has diverse organ development and damage repair roles. However, its role in cardiac homeostasis following hypertrophic stimulation remains unknown. Here we investigate the regulation and function of the FGF18 in pressure overload (PO)-induced pathological cardiac hypertrophy. FGF18 heterozygous (Fgf18+/-) and inducible cardiomyocyte-specific FGF18 knockout (Fgf18-CKO) male mice exposed to transverse aortic constriction (TAC) demonstrate exacerbated pathological cardiac hypertrophy with increased oxidative stress, cardiomyocyte death, fibrosis, and dysfunction. In contrast, cardiac-specific overexpression of FGF18 alleviates hypertrophy, decreased oxidative stress, attenuates cardiomyocyte apoptosis, and ameliorates fibrosis and cardiac function. Tyrosine-protein kinase FYN (FYN), the downstream factor of FGF18, was identified by bioinformatics analysis, LC-MS/MS and experiment validation. Mechanistic studies indicate that FGF18/FGFR3 promote FYN activity and expression and negatively regulate NADPH oxidase 4 (NOX4), thereby inhibiting reactive oxygen species (ROS) generation and alleviating pathological cardiac hypertrophy. This study uncovered the previously unknown cardioprotective effect of FGF18 mediated by the maintenance of redox homeostasis through the FYN/NOX4 signaling axis in male mice, suggesting a promising therapeutic target for the treatment of cardiac hypertrophy.


Assuntos
Fatores de Crescimento de Fibroblastos , Espectrometria de Massas em Tandem , Masculino , Animais , Camundongos , Cromatografia Líquida , Camundongos Knockout , Miócitos Cardíacos , Cardiomegalia
8.
Biosensors (Basel) ; 13(2)2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36831999

RESUMO

Carbon dots (CDs) are widely used in the detection of foodborne contaminants because of their biocompatibility, photoluminescence stability, and ease of chemical modification. In order to solve the interference problem of complexity in food matrices, the development of ratiometric fluorescence sensors shows great prospects. In this review, the progress of ratiometric fluorescence sensors based on CDs in foodborne contaminant detection in recent years will be summarized, focusing on the functionalized modification of CDs, the fluorescence sensing mechanism, the types of ratiometric fluorescence sensors, and the application of portable devices. In addition, the outlook on the development of the field will be presented, with the development of smartphone applications and related software helping to better enable the on-site detection of foodborne contaminants to ensure food safety and human health.


Assuntos
Pontos Quânticos , Humanos , Carbono , Fluorescência , Inocuidade dos Alimentos , Alimentos , Corantes Fluorescentes
9.
Biosens Bioelectron ; 223: 115029, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36580814

RESUMO

The accurate determination of tumor biomarkers in blood is of vital significance in the diagnosis and therapy of tumor disease. In this research, an innovative sandwich-type electrochemical immunosensor is designed for the ultrasensitive determination of tumor biomarker AFP using spherical nucleic acids-templated silver nanoclusters (AgNCs) sensing platform. For this purpose, on one hand, DNA functionalized gold nanoparticles (AuNPs@DNA) is selected not only as the cross-linker to immobilize the primary antibody (anti-AFP antibody 1, Ab1) to obtain AuNPs@DNA-Ab1, but also as the template for synthesizing AgNCs on AuNPs to form AuNPs@DNA-AgNCs. On the other hand, p-sulfonated calix[4]arene (pSC4) modified Au is chosen to immobilize the secondary antibody (anti-AFP antibody 2, Ab2) through host-guest recognition between Ab2 and pSC4. When AFP is encountered, the immunoreaction signal can be significantly amplified by the electrochemical reduction of AgNCs. Under optimal circumstances, the sandwich-type electrochemical immunosensor exhibits broad limit of linearity from 0.001 to 100 ng mL-1 (R2 = 0.997) and low detection limit of 7.74 fg mL-1 (S/N = 3). The immunosensor possesses excellent repeatability and selectivity, offering a novel method for sensitive clinical diagnosis of tumor markers in human hepatocellular carcinoma.


Assuntos
Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Ácidos Nucleicos , Humanos , Biomarcadores Tumorais , Ouro , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Anticorpos , Técnicas Eletroquímicas/métodos , Limite de Detecção
10.
Redox Biol ; 56: 102468, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36113339

RESUMO

Acute myocardial infarction (MI) triggers oxidative stress, which worsen cardiac function, eventually leads to remodeling and heart failure. Unfortunately, effective therapeutic approaches are lacking. Fibroblast growth factor 7 (FGF7) is proved with respect to its proliferative effects and high expression level during embryonic heart development. However, the regulatory role of FGF7 in cardiovascular disease, especially MI, remains unclear. FGF7 expression was significantly decreased in a mouse model at 7 days after MI. Further experiments suggested that FGF7 alleviated MI-induced cell apoptosis and improved cardiac function. Mechanistic studies revealed that FGF7 attenuated MI by inhibiting oxidative stress. Overexpression of FGF7 actives nuclear factor erythroid 2-related factor 2 (Nrf2) and scavenging of reactive oxygen species (ROS), and thereby improved oxidative stress, mainly controlled by the phosphatidylinositol-3-kinase α (PI3Kα)/AKT signaling pathway. The effects of FGF7 were partly abrogated in Nrf2 deficiency mice. In addition, overexpression of FGF7 promoted hexokinase2 (HXK2) and mitochondrial membrane translocation and suppressed mitochondrial superoxide production to decrease oxidative stress. The role of HXK2 in FGF7-mediated improvement of mitochondrial superoxide production and protection against MI was verified using a HXK2 inhibitor (3-BrPA) and a HXKII VDAC binding domain (HXK2VBD) peptide, which competitively inhibits localization of HXK2 on mitochondria. Furthermore, inhibition of PI3Kα/AKT signaling abolished regulation of Nrf2 and HXK2 by FGF7 upon MI. Together, these results indicate that the cardio protection of FGF7 under MI injury is mostly attributable to its role in maintaining redox homeostasis via Nrf2 and HXK2, which is mediated by PI3Kα/AKT signaling.


Assuntos
Infarto do Miocárdio , Fator 2 Relacionado a NF-E2 , Animais , Fator 7 de Crescimento de Fibroblastos/metabolismo , Fator 7 de Crescimento de Fibroblastos/farmacologia , Camundongos , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Fosfatidilinositol 3-Quinase/metabolismo , Fosfatidilinositóis/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxidos
11.
Nanoscale ; 14(30): 10844-10850, 2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35838371

RESUMO

Although various nanomaterials have been designed as intracellular delivery tools, the following aspects have become obstacles to limit their development, like a complex and time-consuming synthesis process, as well as relatively limited application areas (i.e. biosensing or cell imaging). Here, we developed a novel nano-delivery system called "nano-sperm" with low cytotoxicity and high biocompatibility. In this system, we used DNA oligonucleotides as a backbone to synthesize a nanostructure with silver nanoclusters in the head and functional fragments in the tail, which is shaped like a sperm, to achieve dual functions of ultrafast delivery and imaging/therapy. As a model, we analyzed the possibility of the "nano-sperm" carrying DNA with different structures for imaging or survivin-asDNA for tumor therapy. Therefore, this work reports a novel bifunctional high-speed delivery vehicle, which successfully fills the gap in the field of tumor therapy using DNA-templated nanoclusters as a delivery vehicle.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Neoplasias , DNA/química , DNA Antissenso , Humanos , Nanopartículas Metálicas/química , Nanoestruturas/química , Prata/química
12.
Bioelectrochemistry ; 147: 108200, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35816908

RESUMO

In this work, an ultrasensitive immunosensor for amperometric determination of alpha-fetoprotein (AFP) was developed utilizing Ag and Cu nanoparticles on polydopamine (PDA) functionalized cellulose nanofibrils (CNFs) composite (CNFs/PDA/Cu-Ag) as signal amplifier. PDA was first prepared by self-polymerizing of dopamine, and then was adsorbed on CNFs. The obtained CNFs/PDA was applied as substrate to electrolessly deposit Cu-Ag nanoparticles, using NaBH4 as reducing agent. The structure and morphology of the synthesized CNFs/PDA/Cu-Ag nanocomposite were analyzed through Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, scanning electron microscopy, particle size analyzer and transmission electron microscopy. The CNFs/PDA/Cu-Ag modified glassy carbon electrode can fix AFP antibody (Ab), and further capture AFP specifically. Electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the assembly process of immunosensor. The immunoreaction was amplified by electrocatalytical reduction of H2O2 on Cu-Ag nanoparticles, through which AFP was quantitatively detected. The developed sensor exhibits wide linear range of 0.01-100 ng mL-1 (R2 = 0.9963) with low detection limit of 4.27 pg mL-1 (S/N = 3). In addition, it has been used for the detection of AFP in human serum, manifesting its preeminent application prospect in early liver cancer diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Nanocompostos , Técnicas Biossensoriais/métodos , Celulose , Cobre , Técnicas Eletroquímicas/métodos , Humanos , Peróxido de Hidrogênio/química , Imunoensaio/métodos , Indóis , Limite de Detecção , Nanopartículas Metálicas/química , Nanocompostos/química , Polímeros , Prata , alfa-Fetoproteínas
13.
Cell Death Dis ; 13(3): 276, 2022 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-35351862

RESUMO

Cardiac hypertrophy occurs initially in response to an increased cardiac load as a compensatory mechanism to maintain cardiac output. However, sustained pathological hypertrophy can develop into heart failure and cause sudden death. Fibroblast growth factor 20 (FGF20) is a member of the fibroblast growth factor family, which involved in apoptosis, aging, inflammation, and autophagy. The precise function of FGF20 in pathological cardiac hypertrophy is unclear. In this study, we demonstrated that FGF20 was significantly decreased in response to hypertrophic stimulation. In contrast, overexpression of FGF20 protected against pressure overload-induced cardiac hypertrophy. Mechanistically, we found that FGF20 upregulates SIRT1 expression, causing deacetylation of FOXO1; this effect promotes the transcription of downstream antioxidant genes, thus inhibits oxidative stress. In content, the anti-hypertrophic effect of FGF20 was largely counteracted in SIRT1-knockout mice, accompanied by an increase in oxidative stress. In summary, our findings reveal a previously unknown protective effect of FGF20 on pathological cardiac hypertrophy by reducing oxidative stress through activation of the SIRT1 signaling pathway. FGF20 is a potential novel molecular target for preventing and treating pressure overload-induced myocardial injury.


Assuntos
Cardiomegalia , Sirtuína 1 , Animais , Cardiomegalia/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos Cardíacos/metabolismo , Transdução de Sinais , Sirtuína 1/genética , Sirtuína 1/metabolismo
14.
Small ; 17(29): e2101224, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34145748

RESUMO

The delivery of mRNA to manipulate protein expression has attracted widespread attention, since that mRNA overcomes the problem of infection and mutation risks in transgenes and can work as drugs for the treatment of diseases. Although there are currently some vehicles that deliver mRNA into cells, they have not yet reached a good balance in terms of expression efficiency and biocompatibility. Here, a DNA nano-hydrogel system for mRNA delivery is developed. The nano-hydrogel is all composed of DNA except the target mRNA, so it has superior biocompatibility compared with those chemical vehicles. In parallel, the nano-hydrogel can be compacted into a nanosphere under the crosslinking by well-designed "X"-shaped DNA scaffolds and DNA linkers, facilitating the delivery into cells through endocytosis. In addition, smart intracellular release of the mRNA is achieved by incorporating a pH-responsive i-motif structure into the nano-hydrogel. Thus, taking the efficient delivery and release together, mRNA can be translated into the corresponding protein with a high efficiency, which is comparable to that of the commercial liposome but with a much better biocompatibility. Due to the excellent biocompatibility and efficiency, this nano-hydrogel system is expected to become a competitive alternative for delivering functional mRNA in vivo.


Assuntos
DNA , Hidrogéis , Sistemas de Liberação de Medicamentos , Humanos , Concentração de Íons de Hidrogênio , RNA Mensageiro/genética
15.
Analyst ; 144(13): 4060-4065, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31165121

RESUMO

In this work, we propose a novel concept and a proof-of-concept strategy for the fabrication of a pH-based immunoassay platform with a certain degree of universality and scalability to make it adaptable for different application scenarios. The immunoreactions for the target detection are converted to pH changes through an engineered and optimized isothermal nucleic acid amplification, named exponential amplification reaction (EXPAR). Thus, a variety of well-developed methods for pH analysis, e.g. pH indicators, pH-strips and pH meters, can be applied for immunoassay directly. Here, we show that this proof-of-concept strategy is applicable for both macromolecular and micromolecular antigens by adopting human platelet-derived growth factor-BB (PDGF-BB) and chloramphenicol (CAP) as the model targets, respectively. The detection can be achieved using a colorimetric pH indicator after a 15 min reaction of the immuno-triggered isothermal nucleic acid amplification. In addition, compared with the traditional enzyme-linked immunosorbent assay (ELISA), the performance of our strategy, especially the detection limits, is improved to varying degrees for different targets, making the strategy a promising alternative for diverse application scenarios of immunoassay.

16.
Analyst ; 144(6): 1955-1959, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30694265

RESUMO

As a bifunctional enzyme, T4 polynucleotide kinase phosphatase (T4 PNKP) catalyzes the phosphorylation of 5'-hydroxyl, and also removes the terminal 3'-phosphate group. This is closely related to the restructuring, replication, and damage repair of nucleic acid. In this paper, we describe a new method for the sensitive detection of T4 PNKP activity based on the isothermal EXPonential amplification reaction (EXPAR). T4 PNKP can be linearly assayed in the range from 0.001 to 0.01 U mL-1 with a detection limit of 7.9 × 10-4 U mL-1. Moreover, the method exhibits high specificity and sensitivity and can be applied in the enzyme analysis of complex serum samples. In view of its simplicity and moderate experimental conditions, the method may suitable for use in a commercial kit for the analysis of T4 PNKP activity.


Assuntos
Bacteriófago T4/enzimologia , Técnicas Biossensoriais/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Soro/metabolismo , Animais , Bovinos , Quadruplex G , Limite de Detecção , Fosforilação
17.
Environ Microbiol ; 21(2): 772-783, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30548192

RESUMO

Colorectal cancer (CRC) is a common disease worldwide that is strongly associated with the gut microbiota. However, little is known regarding the gut microbiota after surgical treatment. 16S rRNA gene sequencing was used to evaluate differences in gut microbiota among colorectal adenoma patients, CRC patients, CRC postoperative patients and healthy controls by comparing gut microbiota diversity, overall composition and taxonomic signature abundance. The gut microbiota of CRC patients, adenoma patients and healthy controls developed in accordance with the adenoma-carcinoma sequence, with impressive shifts in the gut microbiota before or during the development of CRC. The gut microbiota of postoperative patients and CRC patients differed significantly. Subdividing CRC postoperative patients according to the presence or absence of newly developed adenoma which based on the colonoscopy findings revealed that the gut microbiota of newly developed adenoma patients differed significantly from that of clean intestine patients and was more similar to the gut microbiota of carcinoma patients than to the gut microbiota of healthy controls. The alterations of the gut microbiota between the two groups of postoperative patients corresponded to CRC prognosis. More importantly, we used the different gut microbiota as biomarkers to distinguish postoperative patients with or without newly developed adenoma, achieving an AUC value of 0.72. These insights on the changes in the gut microbiota of CRC patients after surgical treatment may allow the use of the microbiota as non-invasive biomarkers for the diagnosis of newly developed adenomas and to help prevent cancer recurrence in postoperative patients.


Assuntos
Bactérias/isolamento & purificação , Neoplasias Colorretais/microbiologia , Neoplasias Colorretais/cirurgia , Microbioma Gastrointestinal , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , Bactérias/genética , Feminino , Humanos , Intestinos/microbiologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Int J Biol Macromol ; 118(Pt A): 1257-1266, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30021396

RESUMO

To meet the progressive requirements for bone regeneration purpose, injectable hydrogels have attracted increasing attention in tissue regeneration and local drug delivery applications. In this study, we report a facile method to prepare injectable and degradable polysaccharide-based hydrogels doubly integrated with hydroxyapatite (HAp) nanoparticles and calcium carbonate microspheres (CMs) under physiological condition. The mechanism of cross-linking is attributed to the Schiff-base reaction between amino and aldehyde groups of carboxymethyl chitosan (CMCS) and oxidized alginate (OAlg), respectively. Synchronously, tetracycline hydrochloride (TH) loaded CMs were fabricated by the precipitation reaction with an average diameter of 6.62 µm. To enhance bioactive and mechanical properties, nano-HAp and CMs containing TH were encapsulated into the polysaccharide-based hydrogel to form injectable gel scaffolds for imitation of bone niche. The gelation time, morphology, mechanical properties, swelling ratio and in vitro degradation of the gel scaffolds could be controlled by varying HAp and CMs contents. Moreover, the composite gel scaffolds had good sustained drug release and antibacterial properties, as confirmed by drugs release calculation and antibacterial evaluation. In addition, the gel scaffolds were found to be self-healing due to dynamic equilibrium of the Schiff-base linkages. These results suggested that the prepared composite gel scaffolds hold great potential for drug delivery and regeneration of irregular bone defects.


Assuntos
Alginatos , Antibacterianos , Osso e Ossos , Carbonato de Cálcio , Quitosana , Sistemas de Liberação de Medicamentos , Durapatita , Hidrogéis , Engenharia Tecidual , Alginatos/química , Alginatos/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Carbonato de Cálcio/química , Carbonato de Cálcio/farmacologia , Quitosana/química , Quitosana/farmacologia , Durapatita/química , Durapatita/farmacologia , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/química , Ácidos Hexurônicos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia
19.
Front Physiol ; 9: 470, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29780327

RESUMO

Disturbance of the gut microbiota is common in liver cirrhosis (LC) patients, the underlying mechanisms of which are yet to be unfolded. This study aims to explore the relationship between small bowel transit (SBT) and gut microbiota in LC patients. Cross-sectional design was applied with 36 LC patients and 20 healthy controls (HCs). The gut microbiota was characterized by 16S rRNA gene sequencing. The Firmicutes/Bacteroidetes (F/B) ratio and the Microbial Dysbiosis index (MDI) were used to evaluate the severity of microbiota dysbiosis. The scintigraphy method was performed in patients to describe the objective values of SBT. Patients were then subdivided according to the Child-Pugh score (threshold = 5) or SBT value (threshold = 0.6) for microbiota analysis. LC patients were characterized by an altered gut microbiota; F/B ratios and MDI were higher than HC in both Child_5 (14.00 ± 14.69 vs. 2.86 ± 0.99, p < 0.01; 0.49 ± 0.80 vs. -0.47 ± 0.69, p < 0.01) and Child_5+ (15.81 ± 15.11 vs. 2.86±0.99, p < 0.01; 1.11 ± 1.05 vs. -0.47 ± 0.69, p < 0.01) sub-groups in patients. Difference in the gut microbiota between Child_ 5 and Child_5+ patients was inappreciable, but the SBT was relatively slower in Child_5+ patients (43 ± 26% vs. 80 ± 15%, p < 0.05). Compared with the Child-Pugh score indicators, SBT showed stronger associations with bacterial genera. A clear difference in the gut microbiota was observed between SBT_0.6- and SBT_0.6+ patients [Pr(>F) = 0.0068, pMANOVA], with higher F/B ratios and MDI in SBT_0.6- patients (19.71 ± 16.62 vs. 7.33 ± 6.65, p < 0.01; 1.02 ± 0.97 vs. 0.20 ± 0.58, p < 0.01). Similar results were observed between the SBT_0.6- and SBT_0.6+ sub-groups of patients with normal liver function and a Child-Pugh score of 5. SBT was negatively correlated with both the F/B ratio and MDI (r = -0.34, p < 0.05; r = -0.38, p < 0.05). Interestingly, an increased capacity for the inferred pathway "bacterial invasion of epithelial cells" in patients, was highly negatively correlated with SBT (r = -0.57, p < 0.01). The severity of microbiota dysbiosis in LC patients depends on SBT rather than Child-Pugh score. SBT per se might be significantly related to the gut microbiota abnormalities observed in patients with LC.

20.
Cell Physiol Biochem ; 47(2): 641-653, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29794468

RESUMO

BACKGROUND/AIMS: Cholangiocarcinoma (CCA) is a malignant tumor that is resistant to chemotherapy, so new therapeutic agents are needed. Allicin which is rapidly converted from allin by allinase, is one of the most biologically active compounds in freshly crushed garlic and has been shown to have strong anti-tumor effects. Our aim was to explore the molecular mechanism by which allicin affects the cell proliferation and invasion of CCA. METHODS: Cell viability and apoptosis were measured using the CCK-8 assay, colony formation assay, and flow cytometry. Cell migration and invasion were evaluated by wound healing and Transwell assays, respectively. The expression of several proteins involved in cell apoptosis and invasion were assessed by Western blot. The activation of STAT3 signaling was detected by Western blot and immunofluorescence staining. The involvement of SHP-1 was determined using small interfering RNA (siRNA). Moreover, a nude mouse model of human CCA was established to assess the anti-tumor effects of allicin in vivo. RESULTS: Allicin significantly suppressed CCA cell proliferation by activating the caspase cascade, inducing apoptosis, and reducing the expression of proteins downstream of STAT3, such as B-cell lymphoma 2 (Bcl-2), while upregulating Bcl-2-associated X (Bax) protein. In addition, allicin inhibited the migration, invasion, and epithelial-mesenchymal transition (EMT) of CCA cells. Moreover, the protein expression of MMP-2 and MMP-9 was significantly downregulated in CCA cells treated with allicin compared with CCA cells treated with control. Mechanistic investigations indicated that allicin upregulated SHP-1 expression in CCA, and pervanadate treatment reversed the allicin-induced downregulation of STAT3. Moreover, suppression of SHP-1 by siRNA overturned the effect of allicin on the induction of SHP-1 and inhibition of STAT3 activation. Additionally, treatment with allicin attenuated tumor growth in the nude mouse model of CCA. CONCLUSIONS: Our findings suggest that allicin suppresses cell proliferation and invasion via STAT3 signaling and may be a potential therapeutic agent for CCA.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ácidos Sulfínicos/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Neoplasias dos Ductos Biliares/tratamento farmacológico , Neoplasias dos Ductos Biliares/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Colangiocarcinoma/tratamento farmacológico , Colangiocarcinoma/patologia , Dissulfetos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Metaloproteinases da Matriz/metabolismo , Camundongos , Camundongos Nus , Proteína Tirosina Fosfatase não Receptora Tipo 6/antagonistas & inibidores , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT3/genética , Ácidos Sulfínicos/química , Ácidos Sulfínicos/metabolismo , Ácidos Sulfínicos/uso terapêutico , Transplante Heterólogo
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