Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Research (Wash D C) ; 7: 0363, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38694198

RESUMO

Combined hyperlipidemia (CHL) manifests as elevated cholesterol and triglycerides, associated with fatty liver and cardiovascular diseases. Emerging evidence underscores the crucial role of the intestinal microbiota in metabolic disorders. However, the potential therapeutic viability of remodeling the intestinal microbiota in CHL remains uncertain. In this study, CHL was induced in low-density lipoprotein receptor-deficient (LDLR-/-) hamsters through an 8-week high-fat and high-cholesterol (HFHC) diet or a 4-month high-cholesterol (HC) diet. Placebo or antibiotics were administered through separate or cohousing approaches. Analysis through 16S rDNA sequencing revealed that intermittent antibiotic treatment and the cohousing approach effectively modulated the gut microbiota community without impacting its overall abundance in LDLR-/- hamsters exhibiting severe CHL. Antibiotic treatment mitigated HFHC diet-induced obesity, hyperglycemia, and hyperlipidemia, enhancing thermogenesis and alleviating nonalcoholic steatohepatitis (NASH), concurrently reducing atherosclerotic lesions in LDLR-/- hamsters. Metabolomic analysis revealed a favorable liver lipid metabolism profile. Increased levels of microbiota-derived metabolites, notably butyrate and glycylglycine, also ameliorated NASH and atherosclerosis in HFHC diet-fed LDLR-/- hamsters. Notably, antibiotics, butyrate, and glycylglycine treatment exhibited protective effects in LDLR-/- hamsters on an HC diet, aligning with outcomes observed in the HFHC diet scenario. Our findings highlight the efficacy of remodeling gut microbiota through antibiotic treatment and cohousing in improving obesity, NASH, and atherosclerosis associated with refractory CHL. Increased levels of beneficial microbiota-derived metabolites suggest a potential avenue for microbiome-mediated therapies in addressing CHL-associated diseases.

2.
Psychol Res Behav Manag ; 16: 4353-4365, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37908679

RESUMO

Objective: Learner dependence on short videos has many pitfalls for learning outcomes, but the negative effects of excessive short video use have been little discussed in the learning psychology literature. Therefore, this study investigated the effects of excessive short video use on anxiety, depression, prospective memory, and academically delayed gratification (ADOG) in relation to online gaming-related behaviours, and explored the possible mechanisms by which excessive online gaming and short video use may lead to decreased ADOG, to expand our understanding of excessive short video use. Methods: Based on the whole class random sampling method, a questionnaire survey was conducted among college students in Northern Anhui, China from May 7 to July 27, 2022. The questionnaires included the Generalized Anxiety Disorder Scale (GAD-7), Patient Health Questionnaire Scale (PHQ-9), Prospective and Retrospective Memory (PRM) Questionnaire, and ADOG Scale. Results: A total of 1016 participants completed the survey. The study found that of all the internet behaviors, 20.8% of the college students mainly played online games, 43.9% mainly played short videos, and 35.3% conducted other online behaviors. When compared with other internet behaviors, online gaming and short video behaviors can cause more serious anxiety/depression and worse PRM and ADOG scores. As time spent playing online games and short videos increased, anxiety and depression became worse, and the scores for PRM and ADOG also declined. Anxiety, depression, and PRM mediate the relationship between time spent on online gaming/short videos and ADOG. Conclusion: Excessive short videos behaviour may produce the same psychological problems and learning problems as online gaming disorder. Excessive short video and online gaming behaviors may affect ADOG performance through anxiety, depression, and prospective memory. These findings could be used as a basis for future studies on the improvement of ADOG.

3.
J Colloid Interface Sci ; 643: 223-231, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37060698

RESUMO

Lithium-sulfur batteries (LSBs) have become highly promising next-generation secondary lithium batteries owing to their high theoretical energy density and abundance of sulfur. Nevertheless, the large-scale application of LSBs is still restricted by the shuttle effect of lithium polysulfide (LiPSs) and the potential fire hazard caused by flammable electrolytes. Herein, three electrolyte-insoluble brominated flame retardants (BFRs) are selected and coated on both sides of commercial polypropylene separators by a facile slurry coating method. The effects of the three BFRs on the safety and electrochemical properties of LSBs are characterized and compared. The coating modification separators greatly improves the flame retardancy of LSBs through radical elimination mechanism. The self-extinguishing time of the electrolyte is reduced from 0.66 s/mg to 0.20 s/mg. Moreover, it is demonstrated that the oxygen (O)-containing BFRs exert a significant adsorption capacity and are more advantageous than O-free BFRs in LSBs. In addition, octabromoether (BDDP) coated separator is more effective in trapping LiPSs than decabromodiphenyl ether (DBDPO) due to higher O content, which can mitigate the shuttle effect and enhance the cycle and rate performance of LSBs. This simple coating strategy for separators with BFRs offers a strongly competitive option for the large-scale production of high-safety LSBs.

4.
Front Public Health ; 11: 1292422, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38174071

RESUMO

Objective: Evidence from previous studies indicates that impulsive behaviors are closely linked to alcohol use and misuse and that female drinkers are more impulsive than male drinkers. However, studies investigating the psychological mechanisms of alcohol use and impulsivity based on sex differences are relatively limited. Methods: This cross-sectional study comprised 713 residents from 16 cities in Anhui Province, China. Each subject was evaluated for self-reporting measures using several questionnaires, including the general information questionnaire, the Alcohol Use Disorders Identification Test (AUDIT), the Prospective and Retrospective Memory Questionnaire (PRM), the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A), and the Barratt Impulsiveness Scale-11 (BIS-11). Results: Executive function and prospective memory may serve as intermediary links between alcohol use and impulsivity. Although the female alcohol usage level was significantly lower than that of males, the female drinkers had more severe executive dysfunction, prospective memory impairment, and impulsivity than male drinkers. Sex moderated the relationship between alcohol use and impulsivity. Furthermore, the indirect effect of executive function, and prospective memory between AUDIT and BIS was more significant in males than in females. Conclusion: Alcohol consumption may be associated with impulsivity formation through executive dysfunction and PM impairment, implying that impulsivity in those with AUD or at risk for AUD might be treated by improving EF and PM. Alcohol use may cause more severe executive dysfunction, PM impairment, and impulsive behavior in females than in males, and impulsive behavior in women with AUD was more likely to be due to the direct effects of alcohol consumption, while impulsive behavior in men with AUD was more likely to be due to the indirect effects of executive dysfunction and PM impairment. These findings provide both clinical and theoretical foundations for addressing issues related to alcohol use.


Assuntos
Alcoolismo , Memória Episódica , Adulto , Humanos , Feminino , Masculino , Função Executiva/fisiologia , Alcoolismo/epidemiologia , Alcoolismo/psicologia , Estudos Retrospectivos , Estudos Transversais , Consumo de Bebidas Alcoólicas/epidemiologia , Comportamento Impulsivo/fisiologia
5.
Viruses ; 14(11)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36423139

RESUMO

The H9N2 avian influenza virus (AIV) remains a serious threat to the global poultry industry and public health. The hemagglutinin (HA) protein is an essential protective antigen of AIVs and a major target of neutralizing antibodies and vaccines. Therefore, in this study, we used rice-derived HA protein as an immunogen to generate monoclonal antibodies (mAbs) and screened them using an immunoperoxidase monolayer assay and indirect enzyme-linked immunosorbent assay. Eight mAbs reacted well with the recombinant H9N2 AIV and HA protein, four of which exhibited potent inhibitory activity against hemagglutination, while three showed remarkable neutralization capacities. Western blotting confirmed that two mAbs bound to the HA protein. Linear epitopes were identified using the mAbs; a novel linear epitope, 480HKCDDQCM487, was identified. Structural analysis revealed that the novel linear epitope is located at the C-terminus of HA2 near the disulfide bond-linked HA1 and HA2. Alignment of the amino acid sequences showed that the epitope was highly conserved among multiple H9N2 AIV strains. The results of this study provide novel insights for refining vaccine and diagnostic strategies and expand our understanding of the immune response against AIV.


Assuntos
Vírus da Influenza A Subtipo H9N2 , Influenza Aviária , Animais , Hemaglutininas , Epitopos , Anticorpos Neutralizantes , Anticorpos Monoclonais
6.
Carbohydr Polym ; 298: 120132, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36241300

RESUMO

In the past, electromagnetic interference (EMI) shielding materials have achieved great breakthroughs, however, they still suffer from high reflectivity and poor environmental stability, resulting in detrimental secondary pollution and weak adaptability. Herein, an organohydrogel-based EMI shielding material was prepared through cellulose nanofibril-based Pickering emulsion, composed of an MXene network for electron conduction, encapsulated paraffin wax microspheres with MXene-Fe3O4 shells for multiple scattering of the incident wave, and MXene-CNF-Fe3O4-polyacrylamide hybrid interfaces for dielectric polarization. The EMI shielding performance of our organohydrogel shows an absorption-dominated feature. It can effectively shield 99.625 % electromagnetic wave, satisfying the requirement of commercial EMI shielding materials. Moreover, the organohydrogel possesses excellent flame retardancy properties and long-time environment properties to improve safety and reliability; and it also demonstrates sensitive deformation responses as an on-skin sensor. Therefore, our organohydrogel can simultaneously detect human motion and protect human from EMI radiation and accidental burn.


Assuntos
Celulose , Retardadores de Chama , Fenômenos Eletromagnéticos , Emulsões , Humanos , Parafina , Reprodutibilidade dos Testes
7.
Sheng Wu Gong Cheng Xue Bao ; 38(5): 1981-1993, 2022 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-35611743

RESUMO

The aim of this study was to develop a semi-quantitative immunochromatographic method for rapid detection of Newcastle disease virus (NDV) antibodies by expressing HN protein in rice endosperm bioreactor. The recombinant plasmid pUC57-HN was digested by MlyⅠ and XhoⅠ to retrieve the HN gene, while the intermediate vector pMP3 containing promoter, signal peptide and terminator was digested by NaeⅠ and XhoⅠ. The HN gene and the linearized pMP3 were purified and ligated to form a recombinant plasmid pMP3-HN1. Subsequently, pMP3-HN1 and plant vector pCAMBIA1300 were digested by EcoRⅠ and Hind Ⅲ, and the HN1 gene was cloned into pCAMBIA1300. The recombinant plasmid pCAMBIA1300-HN1 was introduced into Agrobacterium tumefaciens EHA105 by electrotransformation, and the pCAMBIA1300-HN1 was transferred into rice callus by agrobacterium-mediated method. After dark culture, callus screening, differentiation, rooting and transplanting, transgenic rice seeds were obtained 4 months later. PCR identified that the HN gene has been inserted into the rice genome. SDS-PAGE and Western blotting indicated that the HN protein was successfully expressed in the positive rice endosperm. The purity of the HN protein was more than 90% by SP cation exchange chromatography and gel filtration chromatography. According to the national standards for the diagnostic techniques of Newcastle disease HI test (HI≥4log2, positive antibody reaction), a colloidal gold labeled purified HN protein was used to prepare a semi-quantitative test strip by double-antibody sandwich method for rapid detection of NDV antibody. The results showed that the test strip did not cross-react with positive sera against other viruses, and the sensitivity of the test strip reached 1:102 400 for standard positive sera of Newcastle disease. Testing of a total of 308 clinical sera showed that the compliance rate of the test strip with HI test was 97.08%, and the Kappa value was 0.942. In conclusion, high purity recombinant HN protein was obtained from rice endosperm, and a simple, rapid, highly sensitive and highly specific semi-quantitative immunochromatographic strip was developed. The test strip could be used for immune evaluation of the Newcastle disease vaccine.


Assuntos
Doença de Newcastle , Oryza , Animais , Anticorpos Antivirais , Galinhas , Proteína HN/genética , Proteína HN/metabolismo , Doença de Newcastle/prevenção & controle , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/metabolismo , Oryza/genética
8.
Carbohydr Polym ; 270: 118384, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34364626

RESUMO

To achieve the co-delivery of chemotherapeutic drugs, genes, and immune agents in a single nanoparticulate system, p-mercaptobenzoic acid-grafted N, N, N-trimethyl chitosan nanoparticles (MT NPs) were successfully synthesized. Paclitaxel (PTX) was encapsulated into the hydrophobic core of the MT NPs, and meanwhile, survivin shRNA-expressing plasmid (iSur-pDNA) and recombinant human interleukin-2 (rhIL-2) were loaded onto the hydrophilic shell of the MT NPs. Owing to the redox-sensitiveness of MT NPs, a rapid release of PTX was triggered by the high concentration of glutathione. The synergistic effects of PTX (1.5 mg/kg), iSur-pDNA (1.875 mg/kg), and rhIL-2 (6 × 105 IU/kg) at a low dose endowed the MT/PTX/pDNA/rhIL-2 NPs with enhanced antitumor efficacies and improved tumor-induced immunosuppression. These results demonstrated that the co-delivery of PTX, iSur-pDNA, and rhIL-2 by the amphiphilic chitosan based NPs with redox-sensitiveness could be a promising strategy in the treatment of tumors.


Assuntos
Antineoplásicos/farmacologia , Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Neoplasias/tratamento farmacológico , Paclitaxel/farmacologia , Animais , Antineoplásicos/química , Protocolos de Quimioterapia Combinada Antineoplásica/química , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Linhagem Celular Tumoral , Feminino , Glutationa/metabolismo , Humanos , Interleucina-2/metabolismo , Camundongos , Neoplasias/metabolismo , Paclitaxel/química , RNA Interferente Pequeno/metabolismo , Survivina/metabolismo
9.
Front Microbiol ; 11: 599739, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33324380

RESUMO

A Viable but non-culturable (VBNC) state is a bacterial survival strategy under reverse conditions. It poses a significant challenge for public health and food safety. In this study, the effect of external environmental conditions including acid, nutrition, and salt concentrations on the formation of S. aureus VBNC states at low temperatures were investigated. Different acidity and nutritional conditions were then applied to food products to control the VBNC state formation. Four different concentration levels of each factor (acid, nutrition, and salt) were selected in a total of 16 experimental groups. Nutrition showed the highest influence on the VBNC state formation S. aureus, followed by acid and salt. The addition of 1% acetic acid could directly kill S. aureus cells and inhibit the formation of the VBNC state with a nutrition concentration of 25, 50, and 100%. A propidium monoazide-polymerase chain reaction (PMA-PCR) assay was applied and considered as a rapid and sensitive method to detect S. aureus in VBNC state with the detection limit of 104 CFU/mL.

10.
Front Microbiol ; 11: 586777, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117324

RESUMO

Objective: This study aimed to investigate the effect of environmental conditions including nutrient content, acetic acid concentration, salt concentration, and temperature on the formation of viable but nonculturable (VBNC) state of Pediococcus acidilactici, as well as its control and detection in food system. Methods: Representing various environmental conditions in different food systems, 16 induction groups were designed for the formation of VBNC state of P. acidilactici. Traditional plate counting was applied to measure the culturable cell numbers, and Live/Dead Bacterial Viability Kit combined with fluorescent microscopy was used to identify viable cells numbers. The inhibition of bacterial growth and VBNC state formation by adjusting the environmental conditions were investigated, and the clearance effect of VBNC cells in crystal cake system was studied. In addition, a propidium monoazide-polymerase chain reaction (PMA-PCR) assay was applied to detect the VBNC P. acidilactici cells in crystal cake food system. Results: Among the environmental conditions included in this study, acetic acid concentration had the greatest effect on the formation of VBNC state of P. acidilactici, followed by nutritional conditions and salt concentration. Reducing nutrients in the environment and treating with 1.0% acetic acid can inhibit P. acidilactici from entering the VBNC state. In the crystal cake system, the growth of P. acidilactici and the formation of VBNC state can be inhibited by adding 1.0% acetic acid and storing at -20°C. In crystal cake system, the PMA-PCR assay can be used to detect VBNC P. acidilactici cells at a concentration higher than 104 cells/ml. Conclusion: The VBNC state of P. acidilactici can be influenced by the changing of environmental conditions, and PMA-PCR assay can be applied in food system for the detection of VBNC P. acidilactici cells.

11.
Microb Pathog ; 145: 104187, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32275941

RESUMO

Methicillin-resistant S. aureus (MRSA) has been considered a potential "Super Bugs", responsible for various infectious diseases. Vancomycin has been the most effective antibitic to treat MRSA originated infections. In this study, we aimed at investigating the genomic features of a vancomycin intermediate-resistance S. aureus strain Guangzhou-SauVS2 isolated from a female patient suffering from chronic renal function failure, emphasizing on its antimicrobial resistance and virulence determinants. The genome has a total length of 2,605,384 bp and the G+C content of 33.21%, with 2,239 predicted genes annotated with GO terms, COG categories, and KEGG pathways. Besides the carriage of vancomycin b-type resistance protein responsible for the vancomycin intermediate-resistance, S. aureus strain Guangzhou-SauVS2 showed resistance to ß-lactams, quinolones, macrolide, and tetracycline, due to the acquisition of corresponding antimicrobial resistance genes. In addition, virulence factors including adherence, antiphagocytosis, iron uptake, and toxin were determined, indicating the pathogenesis of the strain.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Feminino , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Staphylococcus aureus/genética , Vancomicina/farmacologia
12.
J Microbiol Biotechnol ; 30(7): 955-961, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31986245

RESUMO

Lactic acid bacteria (LAB) have caused many microbiological incidents in the brewing industry, resulting in severe economic loss. Meanwhile, traditional culturing method for detecting LAB are time-consuming for brewers. The present review introduces LAB as spoilage microbes in daily life, with focus on LAB in the brewing industry, targeting at the spoilage mechanism of LAB in brewing industry including the special metabolisms, the exist of the viable but nonculturable (VBNC) state and the hop resistance. At the same time, this review compares the traditional and novel rapid detection methods for these microorganisms which may provide innovative control and detection strategies for preventing alcoholic beverage spoilage, such as improvement of microbiological quality control using advanced culture media or different isothermal amplification methods.


Assuntos
Indústria Alimentícia , Microbiologia de Alimentos , Lactobacillales , Cerveja , Meios de Cultura , Contaminação de Alimentos , Inocuidade dos Alimentos
13.
Anal Chem ; 91(21): 14125-14132, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31583883

RESUMO

Herein, an ultrasensitive electrochemiluminescent (ECL) strategy was proposed based on a highly efficient dynamic DNA machine based on microRNA triggered free movement on the lipid bilayer interface. Typically, the lipid bilayer is constructed on the electrode surface modified with nafion@ECL luminophore and gold nanoparticles to immobilize the DNA walker labeled with cholesterol and hairpin nucleotides labeled with cholesterol and ferrocene (Fc), based on the cholesterol-lipid interaction. On this state, Fc was close to the ECL luminophore, performing a quenched ECL emission. In the presence of target microRNA 21, it could trigger the entropy beacon-based DNA amplification to convert microRNA to massive special DNA sequences, which could further hybridize with the blocking DNA on DNA walker to reactivate the DNA walker and thus trigger the DNA walker-based amplification to make Fc to be far from the ECL luminophore, performing a recovered ECL emission related with the concentration of microRNA 21. Compared with the conventional DNA walker immobilized on the interface via chemical bonds or physical adsorption, a higher reaction efficiency could be achieved due to the free movements of DNA walker and its substrates on the interface. As expected, satisfactory performances for the detection of microRNA 21 were achieved with a detection limit of 0.4 fM and quantitative estimation in cells. Furthermore, this dynamic DNA machine-based ECL strategy could be readily expanded for the detection of other biomarkers for clinical diagnosis.


Assuntos
Técnicas Biossensoriais , DNA/química , Técnicas Eletroquímicas , Bicamadas Lipídicas/química , Medições Luminescentes , MicroRNAs/química , Termodinâmica , Eletrodos , Células HeLa , Humanos , Células MCF-7 , Técnicas de Amplificação de Ácido Nucleico , Propriedades de Superfície , Células Tumorais Cultivadas
14.
Microbiologyopen ; 8(9): e00853, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31179649

RESUMO

The inhibition of microbial biofilms is a significant concern in food safety. In the present study, the inhibitory effect of sodium citrate and cinnamic aldehyde on biofilm formation at minimum inhibitory concentrations (MICs) and sub-MICs was investigated for Escherichia coli O157:H7 and Staphylococcus aureus. The biofilm inhibition rate was measured to evaluate the effect of sodium citrate on S. aureus biofilms at 24, 48, 72, and 96 hr. According to the results, an antibiofilm effect was shown by both food additives, with 10 mg/ml of sodium citrate exhibiting the greatest inhibition of S. aureus biofilms at 24 hr (inhibition rate as high as 77.51%). These findings strongly suggest that sodium citrate exhibits a pronounced inhibitory effect on biofilm formation with great potential in the extension of food preservation and storage.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Escherichia coli O157/efeitos dos fármacos , Aditivos Alimentares/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Acroleína/análogos & derivados , Acroleína/farmacologia , Testes de Sensibilidade Microbiana , Citrato de Sódio/farmacologia , Fatores de Tempo
15.
Biol Reprod ; 100(2): 455-467, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30346485

RESUMO

The direct role of melatonin in mammary glands of dairy goats has remained obscure. This study aimed to evaluate the expression of melatonin membrane receptors (MT1 and MT2) in the pituitary and mammary glands of dairy goats during lactation, and to investigate the role of melatonin in mammary function. Both MT1 and MT2 were consistently expressed in the pituitary and mammary eight glands throughout the lactation period, and their levels were lower in 9 March (group I), June (group III), and September (group V) than in May (group II) and August (group IV). The expression patterns of pituitary and mammary MT1 and MT2 were consistent with those of blood melatonin during lactation. Furthermore, the mammary prolactin (PRL), and pituitary growth hormone (GH) and PRL mRNA expression showed an inverse trend in relation to blood melatonin levels. In mammary tissues, MT1 and MT2 immunoreactivity was predominantly located in the mammary epithelial cells (MECs). In addition, a dose- and time-dependent inhibition on cell viability was observed in cultured MECs. At the dose of 10 and 100 pg/ml, melatonin decreased mammary ß-casein and PRL expression. Furthermore, the inhibitory effects of melatonin were blocked by luzindole, a nonselective MT1 and MT2 receptor antagonist. In addition, melatonin promoted MT1 and MT2 expression in cultured MECs. In conclusion, the presence of MT1 and MT2 in the pituitary and mammary glands and the inhibitory effects of melatonin on cell viability, ß-casein, and PRL expression in MECs suggest the potential regulation by melatonin in goat mammary function.


Assuntos
Cabras/fisiologia , Lactação/efeitos dos fármacos , Glândulas Mamárias Animais/efeitos dos fármacos , Melatonina/farmacologia , Animais , Caseínas/genética , Caseínas/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Feminino , Regulação da Expressão Gênica , Metaloproteinase 14 da Matriz/genética , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinase 15 da Matriz/genética , Metaloproteinase 15 da Matriz/metabolismo , Prolactina/genética , Prolactina/metabolismo
16.
Gen Comp Endocrinol ; 260: 115-124, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29366624

RESUMO

Little is known about ghrelin's effects on cell proliferation in pregnant mammary epithelial cells (MECs) even though it is known to be a mitogen for a variety of other cell types. The objectives of this study were to evaluate the expression and localization of ghrelin and its functional receptor, GHSR-1a, in the mammary glands of dairy goats during pregnancy and to investigate the direct role of ghrelin in cell proliferation of primary cultured MECs. Compared to the early stage (days 30) of pregnancy, the abundance of transcripts and protein of ghrelin and GHSR-1a were significantly greater in mid- and late-phases (between days 90 and days 120) of pregnancy (p < .05). Immunohistochemistry analysis showed that ghrelin and GHSR-1a were predominantly localized in the alveolar and ductal mammary epithelial cells at various stages of pregnancy. In our in vitro experiments, ghrelin induced a dose- and time-dependent promotory effect on cell proliferation of MECs. At the dose of 103 pg/mL treatment 24 h, ghrelin augmented the expression of proliferation-related peptides (PCNA and cyclin B1). Furthermore, ghrelin promoted the expression of prolactin (PRL) and GHSR-1a in cultured MECs. Additionally, the stimulatory effects of ghrelin were blocked by d-Lys3-GHRP6, a selective antagonist of GHSR-1a. As the temporal changes in ghrelin and GHSR-1a expression in pregnant goat mammary glands coincided with the mammary growth and development during the pregnancy, activation of GHSR-1a signal transduction pathways by ghrelin may play a direct role in the regulation of mammary growth in dairy goats.


Assuntos
Proliferação de Células , Células Epiteliais/fisiologia , Grelina/genética , Grelina/farmacologia , Cabras , Glândulas Mamárias Animais/metabolismo , Prenhez , Animais , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Células Cultivadas , Indústria de Laticínios , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Grelina/metabolismo , Cabras/genética , Cabras/fisiologia , Lactação/genética , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/crescimento & desenvolvimento , Gravidez , Receptores de Grelina/genética , Receptores de Grelina/metabolismo , Transdução de Sinais/efeitos dos fármacos
17.
Theriogenology ; 108: 297-305, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29277070

RESUMO

The direct effect of melatonin on porcine luteal function during the pregnancy remains unknown. The objective of the study was to analyse the molecular mechanism(s) by which melatonin directly affects progesterone (P4) production in the corpus luteum (CL) of pregnant sows. We evaluated the localization of melatonin membrane receptors (MT1 and MT2) in CL, and investigated the effect of melatonin on P4 secretion along with the expression of P4 synthesis intermediates in luteal cells. Immunohistochemistry analysis showed that MT1 and MT2 were predominantly localized in luteal cells in pregnant luteal tissues. The results of our in vitro experiments showed that melatonin from 5 to 625 pg/mL was able to significantly increase P4 release (P < 0.05) in a dose-dependent manner. And at the dose of 125 pg/mL treatment, the time-dependent effect on P4 secretion was observed. Furthermore, melatonin from 5 to 625 pg/mL up-regulated both P450scc and StAR expression (P < 0.05) in a dose-dependent manner, and the effect was also time-dependent. No difference of 3ß hydroxysteroid dehydrogenase (3ß-HSD) expression was observed between control and treatment groups. In addition, melatonin induced a dose- and time-dependent promotion on cell viability. Additionally, the stimulatory effects of melatonin were blocked by luzindole, a non-selective MT1 and MT2 receptor antagonist, or partially blocked by a selective MT2 ligand, 4-phenyl-2-propionamidotetralin (4P-PDOT). The data support the presence of MT1 and MT2 in porcine CL and a regulatory role for melatonin in luteal function through MT1 and MT2-mediated signal transduction pathways.


Assuntos
Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Corpo Lúteo/efeitos dos fármacos , Melatonina/farmacologia , Fosfoproteínas/metabolismo , Progesterona/metabolismo , Suínos , Animais , Corpo Lúteo/metabolismo , Feminino , Imuno-Histoquímica , Receptor MT1 de Melatonina/análise , Receptor MT1 de Melatonina/metabolismo , Receptor MT2 de Melatonina/análise , Receptor MT2 de Melatonina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA