Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 465
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Life Sci ; : 116863, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31513817

RESUMO

AIMS: To determine whether dimethyl fumarate (DMF) can protect against lipopolysaccharide (LPS) -induced myocardial injury. MAIN METHODS: H9c2 cells pretreated with or without DMF were stimulated with LPS. Cell viability and apoptosis were evaluated. Nrf2 and HO-1 expression were detected using Western blotting. Mitochondrial morphology, mitochondrial and superoxide production were observed using confocal microscope. Mitochondrial respiration function was measured using Seahorse bioanalyzer. KEY FINDINGS: (1) The cell viability decreased, LDH release and apoptosis increased in LPS- challenged H9c2 cells. DMF pretreatment brought a higher cell viability, and a lower LDH leakage and apoptosis than those of LPS group (P < 0.01). (2) DMF pretreatment resulted in an increased Nrf2 and HO-1 expression, and enhanced nuclear Nrf2 level in LPS-challenged cells (P < 0.01). (3) Nrf2-siRNA could inhibit DMF-induced enhancement of HO-1 expression and cell viability, and partly abolish DMF-induced reduction of LDH leakage and apoptosis. (4) ERK1/2 inhibitor PD98059 could not only prevent the DMF-induced enhancement of nuclear Nrf2 and HO-1, but also inhibit DMF-induced increase in cell viability. (5) Compared with LPS-challenged cells, DMF pretreatment caused a lower production of mitochondrial superoxide and a higher mitochondrial membrane potential, which could be abolished by Nrf2-siRNA. (6) DMF could attenuate LPS-induced mitochondrial fragmentation and improved mitochondrial respiration function by enhancement of the oxygen consumption rate of basal respiration and ATP production in LPS-challenged cells (P < 0.01). SIGNIFICANCE: DMF protects cardiomyocytes against LPS-induced damage. ERK1/2-dependent activation of Nrf2/HO-1 pathway is responsible for DMF-induced cardioprotection via reduction of oxidative stress, improvement of mitochondrial morphology and energy metabolism.

2.
Small ; : e1902637, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31468738

RESUMO

The atomic structure of free-standing graphene comprises flat hexagonal rings with a 2.5 Å period, which is conventionally considered the only atomic period and determines the unique properties of graphene. Here, an unexpected highly ordered orthorhombic structure of graphene is directly observed with a lattice constant of ≈5 Å, spontaneously formed on various substrates. First-principles computations show that this unconventional structure can be attributed to the dipole between the graphene surface and substrates, which produces an interfacial electric field and induces atomic rearrangement on the graphene surface. Further, the formation of the orthorhombic structure can be controlled by an artificially generated interfacial electric field. Importantly, the 5 Å crystal can be manipulated and transformed in a continuous and reversible manner. Notably, the orthorhombic lattice can control the epitaxial self-assembly of amyloids. The findings reveal new insights about the atomic structure of graphene, and open up new avenues to manipulate graphene lattices.

3.
Hepatol Int ; 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273618

RESUMO

BACKGROUND AND AIMS: Liver stiffness measurement (LSM) by transient elastography (TE) has been assessed for the evaluation of clinically relevant outcomes in patients with chronic liver diseases (CLDs) while with variable results. This systematic review and meta-analysis aims to investigate the relationship between baseline LSM by TE and the development of clinically relevant outcomes. METHODS: The systematic review identified eligible cohorts reporting the association between baseline LSM by TE and risk of hepatic carcinoma (HCC), hepatic decompensation (HD), all-cause and/or liver-related mortality and liver-related events (LREs) in CLD patients. Summary relative risks (RRs) with 95% confidence intervals (CIs) were estimated using a random-effect model. The dose-response association was evaluated by generalized least squares trend (Glst) estimation and restricted cubic splines. Commands of GLST, MKSPLINE, MVMETA were applied for statistical analysis. RESULTS: 62 cohort studies were finally included, reporting on 43,817 participants. For one kPa (kilopascal) increment in baseline liver stiffness (LS), the pooled RR (95% CI) was 1.08 (1.05-1.11) for HCC, 1.08 (1.06-1.11) for all-cause mortality, 1.11 (1.05-1.17) for liver-related mortality, 1.08 (1.06-1.10) for HD and 1.07 (1.04-1.09) for LREs. Furthermore, the nonlinear dose-response analysis indicated that the significant increase in the risk of corresponding clinically relevant outcomes turned to a stable increase or a slight decrease with increasing baseline LS changing primarily in the magnitude of effect rather than the direction. CONCLUSIONS: The dose-response meta-analysis presents a combination between the levels of baseline LS and RRs for each clinically relevant outcome. TE, which is noninvasive, might be a novel strategy for risk stratification and identification of patients at high risk of developing these outcomes.

4.
PLoS One ; 14(7): e0219939, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31318951

RESUMO

OBJECTIVES: The main objective of this study was to explore the associations of family relationships and negative life events with depressive symptoms among Chinese adolescents. METHODS: A cross-sectional study of 3081 middle school students was conducted in Ganzhou City, Jiangxi Province, China. Students were asked to complete questionnaires regarding family relationships, negative life events, and depressive symptoms. A mediation analysis was carried out using a multiple regression analysis and the PROCESS macro method. RESULTS: Of all participants, 19.9% reported experiencing depressive symptoms. The prevalence of depressive symptoms was 13.0% and 29.2% in participants with good and poor parental relationships, and the prevalence of depressive symptoms was 11.4% and 30.9% in participants with closed and alienated parental-child relationships, respectively. Parental relationships, parental-child relationships, and negative life events were positively correlated with depressive symptoms. The effect of parental relationships on depressive symptoms was fully mediated by negative life events (Effect = 0.052, 95% CI = [0.023, 0.082]), while the effect of parent-child relationships on adolescent depressive symptoms was partially mediated by negative life events (Effect = 0.075, 95% CI = [0.048, 0.104]). CONCLUSIONS: Our results showed a high prevalence of depressive symptoms in Chinese adolescents. Poor family relationships may have the potential to increase the risk of depressive symptoms, and they could affect depressive symptoms through negative life events.

5.
ACS Appl Mater Interfaces ; 11(33): 29830-29837, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31361114

RESUMO

The conventional lithium-sulfur battery (LSB) undergoes a "solid-liquid-solid" cathode process during which the intermediate polysulfides dissolve into the electrolyte, leading to a serious "shuttle" reaction and significantly shortened lifespan. Here, we realize a novel "solid → solid" cathode mode for LSBs via a transplantable solid electrolyte interface (SEI). The SEI is in situ formed in a carbonate-based electrolyte with high-concentration dual-salt during the initial discharge process. The solid → solid cathode process does not involve any dissolution of the intermediates; hence, the "shuttle effect" can be totally eliminated. Furthermore, the SEI shows a high electrolyte compatibility and can be transplanted to the conventional carbonate-based/ether-based electrolytes. The sulfur/carbon composite with 65% sulfur delivers a reversible specific capacity of 1009 mA h g-1 and negligible self-discharge. The SEI strategy can successfully break the limitation from the traditional "catholyte" electrode mechanism. Meanwhile, it provides large flexibility for designing high-loading carbon hosts and selecting an electrolyte for high-performance LSBs.

6.
J Affect Disord ; 257: 108-115, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31301610

RESUMO

BACKGROUND: Limited published research has examined the relationships of coping styles and sleep quality with anxiety symptoms in Chinese school adolescents. We aimed to explore the effect of coping styles and sleep quality on anxiety symptoms. Furthermore, we investigated the interactions of coping styles and sleep quality with anxiety symptoms. METHODS: The survey was conducted in Jiangxi Province, China. The Simplified Coping Style Questionnaire, Pittsburgh Sleep Quality Index and Chinese Secondary School Students Anxiety Scale were utilized to assess sleep quality, coping styles and anxiety symptoms, respectively. Multiple logistic regression analysis was applied to explore the relationships of coping styles and sleep quality with anxiety symptoms. RESULTS: A total of 3081 students participated in this study, 50.8% of whom were boys; the number of participants in grades 1, 2 and 3 were 979, 1085 and 1017, respectively. The prevalence of anxiety symptoms was 27.3%. Individuals with poor sleep quality were 3.558 (95% CI = 2.716-4.660) times as likely to have anxiety symptoms than those with good sleep quality. Higher negative coping style scores increased the prevalence of anxiety symptoms (OR = 2.101, 95% CI = 1.894-2.332), whereas higher positive coping style scores were related to reduced odds of anxiety symptoms (OR = 0.892, 95% CI = 0.800-0.995). Interactions of coping styles and sleep quality with anxiety symptoms were not found (all p > 0.05). The association between negative coping style and anxiety symptoms was mediated by sleep quality. LIMITATIONS: This study was cross-sectional and limited to Ganzhou City. CONCLUSIONS: The results of our study showed a higher prevalence of anxiety symptoms compared with the result of a previous study in Chinese school adolescents. Negative coping style and poor sleep quality were associated with an increased prevalence of anxiety symptoms, whereas positive coping style was related to a decreased prevalence of anxiety symptoms. Sleep quality was a mediating factor between negative coping style and anxiety symptoms.

7.
Sci Rep ; 9(1): 9514, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267025

RESUMO

Microalgal Chlorella has been demonstrated to process wastewater efficiently from piggery industry, yet optimization through genetic engineering of such a bio-treatment is currently challenging, largely due to the limited data and knowledge in genomics. In this study, we first investigated the differential growth rates among three wastewater-processing Chlorella strains: Chlorella sorokiniana BD09, Chlorella sorokiniana BD08 and Chlorella sp. Dachan, and the previously published Chlorella sorokiniana UTEX 1602, showing us that BD09 maintains the best tolerance in synthetic wastewater. We then performed genome sequencing and analysis, resulting in a high-quality assembly for each genome with scaffold N50 > 2 Mb and genomic completeness ≥91%, as well as genome annotation with 9,668, 10,240, 9,821 high-confidence gene models predicted for BD09, BD08, and Dachan, respectively. Comparative genomics study unravels that metabolic pathways, which are involved in nitrogen and phosphorus assimilation, were enriched in the faster-growing strains. We found that gene structural variation and genomic rearrangement might contribute to differential capabilities in wastewater tolerance among the strains, as indicated by gene copy number variation, domain reshuffling of orthologs involved, as well as a ~1 Mb-length chromosomal inversion we observed in BD08 and Dachan. In addition, we speculated that an associated bacterium, Microbacterium chocolatum, which was identified within Dachan, play a possible role in synergizing nutrient removal. Our three newly sequenced Chlorella genomes provide a fundamental foundation to understand the molecular basis of abiotic stress tolerance in wastewater treatment, which is essential for future genetic engineering and strain improvement.

8.
Nat Prod Res ; : 1-6, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31184497

RESUMO

Strain HT88 was isolated from the fresh stems of Mallotus nudiflorus L, and it was identified as Nocardiopsis sp. by analyzing its morphology and the 16S rRNA sequence. The extracts of fermented HT88 showed potent antimicrobial activities. Bioassay guided separation of extracts led to eight proline (or hydroxyproline, Hyp)-containing cyclic dipeptides. Their structures were determined by 1D and 2D NMR spectroscopy and ESI mass spectrometry and further comparison with existing 1H and 13C NMR, melting points and specific rotation data. The eight 2,5-diketopiperazines (DKPs) were identified as cyclo(L-Pro-L-Leu) (1), cyclo(Pro-Leu) (2), cyclo(L-trans-Hyp-L-Leu) (3), cyclo(D-trans-Hyp-D-Leu) (4), and cyclo(D-Pro-L-Phe) (5), cyclo(L-Pro-L-Phe) (6), and cyclo(D-cis-Hyp-L-Phe) (7), cyclo(L-trans-Hyp-L-Phe) (8), respectively. Up to date, this is the first isolation of four pairs of proline based DKPs from Nocardiopsis sp.

9.
J Liposome Res ; : 1-9, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31190595

RESUMO

Artificial liver support systems (ALSS), represented by albumin dialysis, are designed to replace the liver detoxification function and to serve as supportive therapy until liver transplantation or liver regeneration. We introduce liposome, which is majorly formed by soybean lecithin as the adsorbent nanomaterial in dialysate for the removal of protein-bound and liver failure-related solutes. The binding rate was detected by ultrafiltration column. In vitro and in vivo dialysis was performed in a recirculation system. Unconjugated bilirubin (52.83-99.87%) and bile salts (50.54-94.75%) were bound by liposomes (5-80 g/L) in a dose-response relationship. The in vitro haemodialysis model showed that the concentration of unconjugated bilirubin (45.64 ± 0.90 µmol/L vs. 54.47 ± 3.48 µmol/L, p < 0.05) and bile salts (153.75 ± 7.72 µmol/L vs. 180.72 ± 7.95 µmol/L, p < 0.05) were significantly decreased in the liposome dialysis group than in the phosphate buffer saline group. The in vivo haemodialysis model showed that 40 g/L liposome-containing dialysate led to a significant higher reduction ratio in total bilirubin (6.56 ± 5.72% vs. -1.86 ± 5.99%, p < 0.05) and more total bile acids (7.63 ± 5.27 µmol vs. 2.13 ± 2.32 µmol, p < 0.05) extracted in the dialysate in comparison with the conventional dialysate. In conclusion, the liposome-added dialysate proved to impose good extraction effects on the unconjugated bilirubin and bile salts. These findings indicate that conventional dialysate supported by this nanomaterial can markedly improve the removal of protein-bound and liver failure-related solutes, thus suggesting a novel and promising liver dialysis system.

10.
Pol J Microbiol ; 68(2): 247-254, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250595

RESUMO

Gastric microbiota provides a biological barrier against the invasion of foreign pathogens from the oral cavity, playing a vital role in maintaining gastrointestinal health. Klebsiella spp. of oral origin causes various infections not only in gastrointestinal tract but also in other organs, with Klebsiella pneumoniae serotype K1 resulting in a liver abscess (KLA) through oral inoculation in mice. However, the relationship between gastric microbiota and the extra-gastrointestinal KLA infection is not clear. In our study, a 454 pyrosequencing analysis of the bacterial 16S rRNA gene shows that the composition of gastric mucosal microbiota in mice with or without KLA infection varies greatly after oral inoculation with K. pneumoniae serotype K1 isolate. Interestingly, only several bacteria taxa show a significant change in gastric mucosal microbiota of KLA mice, including the decreased abundance of Bacteroides, Alisptipes and increased abundance of Streptococcus. It is worth noting that the abundance of Klebsiella exhibits an obvious increase in KLA mice, which might be closely related to KLA infection. At the same time, the endogenous antibiotics, defensins, involved in the regulation of the bacterial microbiota also show an increase in stomach and intestine. All these findings indicate that liver abscess caused by K. pneumoniae oral inoculation has a close relationship with gastric microbiota, which might provide important information for future clinical treatment.Gastric microbiota provides a biological barrier against the invasion of foreign pathogens from the oral cavity, playing a vital role in maintaining gastrointestinal health. Klebsiella spp. of oral origin causes various infections not only in gastrointestinal tract but also in other organs, with Klebsiella pneumoniae serotype K1 resulting in a liver abscess (KLA) through oral inoculation in mice. However, the relationship between gastric microbiota and the extra-gastrointestinal KLA infection is not clear. In our study, a 454 pyrosequencing analysis of the bacterial 16S rRNA gene shows that the composition of gastric mucosal microbiota in mice with or without KLA infection varies greatly after oral inoculation with K. pneumoniae serotype K1 isolate. Interestingly, only several bacteria taxa show a significant change in gastric mucosal microbiota of KLA mice, including the decreased abundance of Bacteroides, Alisptipes and increased abundance of Streptococcus. It is worth noting that the abundance of Klebsiella exhibits an obvious increase in KLA mice, which might be closely related to KLA infection. At the same time, the endogenous antibiotics, defensins, involved in the regulation of the bacterial microbiota also show an increase in stomach and intestine. All these findings indicate that liver abscess caused by K. pneumoniae oral inoculation has a close relationship with gastric microbiota, which might provide important information for future clinical treatment.


Assuntos
Biota , Disbiose/complicações , Mucosa Gástrica/microbiologia , Infecções por Klebsiella/complicações , Abscesso Hepático/complicações , Animais , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Modelos Animais de Doenças , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/patologia , Abscesso Hepático/microbiologia , Abscesso Hepático/patologia , Camundongos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Gigascience ; 8(6)2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-31220251

RESUMO

The information explosion has led to a rapid increase in the amount of data requiring physical storage. However, in the near future, existing storage methods (i.e., magnetic and optical media) will be insufficient to store these exponentially growing data. Therefore, data scientists are continually looking for better, more stable, and space-efficient alternatives to store these huge datasets. Because of its unique biological properties, highly condensed DNA has great potential to become a storage material for the future. Indeed, DNA-based data storage has recently emerged as a promising approach for long-term digital information storage. This review summarizes state-of-the-art methods, including digital-to-DNA coding schemes and the media types used in DNA-based data storage, and provides an overview of recent progress achieved in this field and its exciting future.

12.
Phys Chem Chem Phys ; 21(27): 14511-14515, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31236552

RESUMO

Herein, an unusual blue shift in excimer fluorescence with increasing temperature was observed from a crystal with a discrete π-π anthracene dimer, originating from the more temperature-sensitive intermolecular geometry of the π-π dimer (e.g., π-π distance) compared to the intramolecular geometry of the monomer, which is confirmed by temperature-dependent single-crystal X-ray diffraction (XRD) measurements.

13.
Artigo em Inglês | MEDLINE | ID: mdl-31071223

RESUMO

BACKGROUND: Protein-bound uremic toxins (PBUTs) have received extensive attention, as their accumulation leads to pleiotropic toxic biological effects, while the removal of these solutes by conventional dialysis therapies is severely hampered. This study aimed to examine whether increased removal of PBUTs could be achieved with intravenous lipid emulsion (ILE). METHODS: PBUTs such as 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF), p-cresyl sulfate (PCS) and indoxyl sulfate (IS) were spiked with human serum albumin (HSA) solution and the inhibitory effects of free fatty acid (FFA) on the binding of CMPF, PCS and IS to HSA were examined separately in vitro by ultrafiltration. In vitro dialysis of albumin solution was then performed to investigate the effects of fatty acid (FAs) mixtures infusion on the fractional removal of PBUTs. Finally, the inhibitory effect of FFA on the binding of PBUTs to albumin was examined in uremic rats, and blood purification therapy was conducted to calculate the reduction ratio (RR) and the total solute removal (TSR) of solutes. RESULTS: The percentage protein binding of CMPF, PCS and IS decreased significantly with increasing FFAs concentrations, and the inhibitory effect was more remarkable with the addition of oleic acid or linoleic acid than that of eicosapentaenoic acid and docosahexaenoic acid. In vitro infusion of FAs increased the fractional removal of CMPF to 14.40 ± 2.38%. PCS, IS and indole-3-acetic acid removal increased from 8.00 ± 2.43%, 11.68 ± 1.54% and 15.38 ± 3.97%, respectively, at baseline to 28.21 ± 5.99%, 35.42 ± 5.27% and 40.18 ± 5.05%, respectively, when FAs were present. In vivo, rat serum concentrations of free PBUTs were significantly higher in the ILE group than in the control group, and administration of ILE resulted in higher RRs and more TSR for PBUTs after 3 h of hemodialysis (HD) therapy compared with the control group. CONCLUSIONS: Administration of ILE effectively increased the dialytic removal of PBUTs. This method could be applied to current HD therapy.

14.
Nucleic Acids Res ; 47(W1): W74-W80, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31114893

RESUMO

Identifying active prophages is critical for studying coevolution of phage and bacteria, investigating phage physiology and biochemistry, and engineering designer phages for diverse applications. We present Prophage Hunter, a tool aimed at hunting for active prophages from whole genome assembly of bacteria. Combining sequence similarity-based matching and genetic features-based machine learning classification, we developed a novel scoring system that exhibits higher accuracy than current tools in predicting active prophages on the validation datasets. The option of skipping similarity matching is also available so that there's higher chance for novel phages to be discovered. Prophage Hunter provides a one-stop web service to extract prophage genomes from bacterial genomes, evaluate the activity of the prophages, identify phylogenetically related phages, and annotate the function of phage proteins. Prophage Hunter is freely available at https://pro-hunter.bgi.com/.

15.
Structure ; 27(7): 1162-1170.e3, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31080119

RESUMO

Arrestins, in addition to desensitizing GPCR-induced G protein activation, also mediate G protein-independent signaling by interacting with various signaling proteins. Among these, arrestins regulate MAPK signal transduction by scaffolding mitogen-activated protein kinase (MAPK) signaling components such as MAPKKK, MAPKK, and MAPK. In this study, we investigated the binding mode and interfaces between arrestin-3 and JNK3 using hydrogen/deuterium exchange mass spectrometry, 19F-NMR, and tryptophan-induced Atto 655 fluorescence-quenching techniques. Results suggested that the ß1 strand of arrestin-3 is the major and potentially only interaction site with JNK3. The results also suggested that C-lobe regions near the activation loop of JNK3 form the potential binding interface, which is variable depending on the ATP binding status. Because the ß1 strand of arrestin-3 is buried by the C-terminal strand in its basal state, C-terminal truncation (i.e., pre-activation) of arrestin-3 facilitates the arrestin-3/JNK3 interaction.

16.
Theranostics ; 9(7): 2017-2035, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31037154

RESUMO

Recent studies have demonstrated that bone marrow mesenchymal stem cells (BMSCs) protect the injured neurons of spinal cord injury (SCI) from apoptosis while the underlying mechanism of the protective effect of BMSCs remains unclear. In this study, we found the transfer of mitochondria from BMSCs to injured motor neurons and detected the functional improvement after transplanting. Methods: Primary rat BMSCs were co-cultured with oxygen-glucose deprivation (OGD) injured VSC4.1 motor neurons or primary cortical neurons. FACS analysis was used to detect the transfer of mitochondria from BMSCs to neurons. The bioenergetics profiling of neurons was detected by Extracellular Flux Analysis. Cell viability and apoptosis were also measured. BMSCs and isolated mitochondria were transplanted into SCI rats. TdT-mediated dUTP nick end labelling staining was used to detect apoptotic neurons in the ventral horn. Immunohistochemistry and Western blotting were used to measure protein expression. Re-myelination was examined by transmission electron microscope. BBB scores were used to assess locomotor function. Results: MitoTracker-Red labelled mitochondria of BMSCs could be transferred to the OGD injured neurons. The gap junction intercellular communication (GJIC) potentiator retinoid acid increased the quantity of mitochondria transfer from BMSCs to neurons, while GJIC inhibitor 18ß glycyrrhetinic acid decreased mitochondria transfer. Internalization of mitochondria improved the bioenergetics profile, decreased apoptosis and promoted cell survival in post-OGD motor neurons. Furthermore, both transplantation of mitochondria and BMSCs to the injured spinal cord improved locomotor functional recovery in SCI rats. Conclusions: To our knowledge, this is the first evidence that BMSCs protect against SCI through GJIC to transfer mitochondrial to the injured neurons. Our findings suggested a new therapy strategy of mitochondria transfer for the patients with SCI.

17.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(1): 55-60, 2019 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-31037905

RESUMO

OBJECTIVE: To investigate the effect of small interfering RNA of lactate dehydrogenase A (siLDHA) on migration and invasion of epidermal growth factor receptor 2 (ErbB2) over expressing breast cancer cell line SK-BR-3, MDA-MB-453 and its molecular mechanism. METHODS: SK-BR-3 and MDA-MB-453 cells were transfected with siLDHA to interfere with the expression of LDHA. The transfection of scramble siRNA was used as negative control. The LDHA protein levels were detected by Western blot ( P<0.01). Cell migration and invasion was detected by Transwell assays. Lactate dehydrogenase (LDH) activity was measured by LDH assay kit. The glucose and lactate concentration in the culture media was determined by glucose and lactate assay kit, respectively, and then glucose uptake and lactate production by the cells were calculated. RESULTS: siLDHA downregulated LDHA protein levels in SK-BR-3 and MDA-MB-453 cells ( P<0.01). Compared with negative control group, siLDHA significantly decreased migration and invasion of SK-BR-3 and MDA-MB-453 cells ( P<0.001). siLDHA reduced LDH activity in SK-BR-3 cells, glucose uptake and lactate production in SK-BR-3 and MDA-MB-453 cells, the difference was significant ( P<0.05). CONCLUSION: Knockdown of LDHA by siRNA inhibits the migration and invasion via downregulation of glycolysis in ErbB2 over expressing breast cancer cell line.


Assuntos
Neoplasias da Mama , L-Lactato Desidrogenase/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Humanos , Células MCF-7 , RNA Interferente Pequeno , Receptor ErbB-2
18.
J Ethnopharmacol ; 241: 111934, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31129308

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Plants of genus Celastrus (Celastraceae) have been widely used in traditional Chinese medicine (TCM) and Indian medicine to treat cognitive dysfunction, epilepsy, insomnia, rheumatism, gout, and dyspepsia for thousands of years. AIM OF STUDY: We critically summarized the current evidence on the botanic characterization and distribution, ethnopharmacology, secondary metabolites, pharmacological activities, qualitative and quantitative analysis, and toxicology of Celastrus species to provide perspectives for developing more attractive pharmaceuticals of plant origin. MATERIALS AND METHODS: The relevant information on Celastrus species was gathered from worldwide accepted scientific databases via electronic search (Web of Science, SciFinder, PubMed, Elsevier, SpringerLink, Wiley Online, China Knowledge Resource Integrated, and Google Scholar). Information was also obtained from the literature and books as well as PhD and MSc dissertations. Plant names were validated by "The Plant List" (www.theplantlist.org). RESULTS: Comprehensive analysis of the above mentioned databases and other sources confirmed that ethnomedical uses of plants of Celastrus genus had been recorded in China, India, and other countries in Southern Asia. The phytochemical investigation revealed the presence of ß-dihydroagarofuranoids, diterpenoids, triterpenoids, tetraterpenes, phenylpropanoids, alkaloids, flavonoids, lignans, and others. The crude extracts and isolated constituents have exhibited a wide range of in vitro and in vivo pharmacological effects, including antitumor, cytotoxic, insecticidal, antimicrobial, anti-rheumatoid arthritis (RA), anti-inflammatory, anti-ageing and antioxidative, and neuroprotective activities. CONCLUSION: Plants of genus Celastrus have been confirmed to show a strong potential for therapeutic and health-maintaining effects, in light of their long traditional use and the phytochemical and pharmacological studies summarized here. Currently, pharmacological studies of this genus mainly focus on Celastrus paniculatus Willd. and Celastrus orbiculatus Thunb. Therefore, more pharmacological investigations should be implemented to support traditional uses of other medicinal plants of the genus Celastrus. Moreover, studies on the toxicity, bioavailability, and pharmacokinetics, in addition to clinical trials, are indispensable for assessing the safety and efficacy of the secondary metabolites or extracts obtained from plants belonging to this genus.

19.
ACS Synth Biol ; 8(5): 962-967, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-30964646

RESUMO

Conventional techniques to synchronize bacterial cells often require manual manipulations and lengthy incubation lacking precise temporal control. An automated microfluidic device was recently developed to overcome these limitations. However, it exploits the stalk property of Caulobacter crescentus that undergoes asymmetric stalked and swarmer cell cycle stages and is therefore restricted to this species. To address this shortcoming, we have engineered Escherichia coli cells to adhere to microchannel walls via a synthetic and inducible "stalk". The pole of E. coli is capped by magnetic fluorescent nanoparticles via a polar-localized outer membrane protein. A mass of cells is immobilized in a microfluidic chamber by an externally applied magnetic field. Daughter cells are formed without the induced stalk and hence are flushed out, yielding a synchronous population of "baby" cells. The stalks can be tracked by GFP and nanoparticle fluorescence; no fluorescence signal is detected in the eluted cell population, indicating that it consists solely of daughters. The collected daughter cells display superb synchrony. The results demonstrate a new on-chip method to synchronize the model bacterium E. coli and likely other bacterial species, and also foster the application of synthetic biology to the study of the bacterial cell cycle.

20.
Proc Natl Acad Sci U S A ; 116(18): 9078-9083, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30979801

RESUMO

Major depressive disorder (MDD) is common and disabling, but its neuropathophysiology remains unclear. Most studies of functional brain networks in MDD have had limited statistical power and data analysis approaches have varied widely. The REST-meta-MDD Project of resting-state fMRI (R-fMRI) addresses these issues. Twenty-five research groups in China established the REST-meta-MDD Consortium by contributing R-fMRI data from 1,300 patients with MDD and 1,128 normal controls (NCs). Data were preprocessed locally with a standardized protocol before aggregated group analyses. We focused on functional connectivity (FC) within the default mode network (DMN), frequently reported to be increased in MDD. Instead, we found decreased DMN FC when we compared 848 patients with MDD to 794 NCs from 17 sites after data exclusion. We found FC reduction only in recurrent MDD, not in first-episode drug-naïve MDD. Decreased DMN FC was associated with medication usage but not with MDD duration. DMN FC was also positively related to symptom severity but only in recurrent MDD. Exploratory analyses also revealed alterations in FC of visual, sensory-motor, and dorsal attention networks in MDD. We confirmed the key role of DMN in MDD but found reduced rather than increased FC within the DMN. Future studies should test whether decreased DMN FC mediates response to treatment. All R-fMRI indices of data contributed by the REST-meta-MDD consortium are being shared publicly via the R-fMRI Maps Project.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA