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1.
Int J Dev Neurosci ; 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31910289

RESUMO

Autism spectrum disorder (ASD) comprises a heterogeneous range of neurodevelopmental conditions represented by symptoms including, communication and language deficits, repetitive, and restricted patterns of behavior and inadequate social interactions. Gamma-aminobutyric acid (GABA) is known to mediate I responses in the central nervous system by interacting with GABA signaling receptors. In this context, several recent investigations suggest that imbalances in the GABAergic neurotransmission system may be implicated in the development of ASD as well as several other neurodevelopmental disorders, including Fragile X syndrome (FXS) and Rett syndrome. This review initially expounds the functional role of the GABAergic system in the mature brain and during neurodevelopment. This will be followed by discussions concerning the impact of deficiencies in the system on ASD and the other above-mentioned neurodevelopment disorders. Finally, the connections between these deficiencies and behavioral features observed in the clinic will be considered.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31910357

RESUMO

Background: Oral tongue squamous cell carcinoma (OTSCC) is a common type of oral tumor. LncRNAs (long noncoding RNAs) and miRNAs (microRNAs) were identified as regulators in many human cancers. This study aims to explore the molecular basis of HOXA transcript at the distal tip (HOTTIP) in regulating OTSCC progression. Materials and Methods: The expression of HOTTIP, miR-124-3p, and high-mobility group AT-hook 2 (HMGA2) was detected by quantitative real-time polymerase chain reaction. Next, the proliferation was evaluated by 3-(4,5-dimethylthiazole-2-y1)-2,5-biphenyl tetrazolium bromide (MTT) assay. The migration and invasion were assessed by transwell assay. Furthermore, dual-luciferase reporter assay was performed to confirm the combination between HOTTIP and miR-124-3p, miR-124-3p, and HMGA2. Protein levels of HMGA2, ß-catenin, c-Myc, and E-cadherin were examined by western blot. The nude mice model was employed to test the tumor growth in vivo. Results: HOTTIP was upregulated in OTSCC tissues and cells, and was highly expressed in positive lymph node metastasis and late-stage OTSCC patients. Silencing HOTTIP impeded proliferation, migration, and invasion of OTSCC cells. Moreover, HOTTIP knockdown inhibited proliferation, migration, and invasion of OTSCC cells by targeting miR-124-3p. Besides, miR-124-3p targeted HMGA2 to block proliferation, migration, and invasion. HMGA2 could rescue the inhibitory effects of HOTTIP interference on proliferation, migration, and invasion. In addition, HMGA2 overexpression reversed the downregulation of ß-catenin and c-Myc protein levels and upregulation of E-cadherin level affected by HOTTIP silencing. Finally, HOTTIP silencing repressed tumor growth and resulted in a great rise on miR-124-3p and E-cadherin expression and a distinct fall on HMGA2, ß-catenin, and c-Myc protein levels. Conclusions: HOTTIP knockdown restrained proliferation, migration, and invasion of OTSCC cells by miR-124-3p/HMGA2 axis through Wnt/ß-catenin pathway.

3.
J Hazard Mater ; 384: 121465, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31704114

RESUMO

Microwave-assisted selective degradation successfully converts thermosetting unsaturated polyester resins into a low-swelling (below 10 g g-1) gel material (GM) with a high yield (58-65%) in water at 100°C for only 1 h. The obtained GM possesses rough and porous structure while the content of carboxylate group obtained by cleavage of partial ester groups is more than 10%, varying with the concentration of the catalyst. It is suitable for use as packing of adsorption column to rapidly purify sewage. Super high filtering rates of 18582-27002 L h-1 m-3 without external pressure and high removal efficiency of more than 99.8% were achieved, promoting practical application for rapid removal of organic pollutants.

4.
Pest Manag Sci ; 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31785188

RESUMO

BACKGROUND: Plutella xylostella is a devastating agricultural insect pest of cruciferous plants, including crops. Plant-mediated RNA interference (RNAi) is currently being developed for plant protection. In this study, we investigated the response of P. xylostella exposed to transgenic Arabidopsis thaliana plants that expressed double-stranded RNA (dsRNA) targeting P. xylostella genes of arginine kinase (PxAK) and integrin ß1 subunit (Pxß). RESULTS: Transgenic plants producing dsRNAs of the 384-bp fragment of PxAK (dsAK plants), the 497-bp fragment of Pxß (dsß plants), and the 881 bp of the combination of both genes (dsAK-ß plants) were generated and verified. Insect bioassay with these transgenic plants showed that the development of P. xylostella was affected, causing longer developmental time, and lower pupal weight and pupation rate. P. xylostella mortality rates were 25.0% when exposed to dsAK plants, 22.5% with dsß plants, and 30.0% with dsAK-ß plants, which were all higher than 7.5% for the wild-type plant. PxAK and Pxß in P. xylostella were suppressed by 26.6-79.7% at the transcription level by the transgenic plants. CONCLUSION: These results suggest that plant-mediated RNAi targeting single gene or both PxAK and Pxß may have the potential to control P. xylostella. © 2019 Society of Chemical Industry.

5.
J Thorac Oncol ; 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31843683

RESUMO

INTRODUCTION: Blood-based tumor mutational burden (bTMB) has been studied to differentiate non-small cell lung cancer (NSCLC) patients who would benefit from anti-programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) therapies. However, it failed to predict overall survival (OS) benefits, which warrants further exploration. METHODS: Three independent cohorts of NSCLC patients treated with immunotherapy were used in this study. A new bTMB algorithm was first developed in the two independent cohorts (POPLAR, N=211 and OAK, N=462) and further validated in the third National Cancer Center cohort (NCC, N=64). RESULTS: bTMB-H (bTMB≥cut-off point) was not associated with favorable OS following immunotherapy regardless of the cut-off points in either the POPLAR and OAK or the NCC cohorts (P>0.05) due to its correlation with the circulating tumor DNA (ctDNA) amount, which was associated with poor OS. In the POPLAR and OAK cohorts, upon allele frequency (AF) adjustment, a high allele frequency bTMB (HAF-bTMB, mutation counts with an AF>5%) was strongly correlated with the ctDNA amount (Pearson's r=0.65), while a low allele frequency bTMB (LAF-bTMB, mutation counts with an AF≤5%) was not (Pearson's r=0.09). LAF-bTMB-H was associated with favorable OS (hazard ratio [[HR], 0.70; 95% confidence interval [CI], 0.52-0.95; P=0.02), progression-free survival (PFS) (HR, 0.62; 95% CI, 0.47-0.80; P<0.001), and the objective response rate (ORR) (P<0.001) following immunotherapy but not chemotherapy, with a cut-off point of 12 trained in the POPLAR cohort and validated in the OAK cohort. The LAF-bTMB algorithm was further validated in the NCC cohort in which LAF-bTMB-H was associated with OS (HR, 0.20; 95% CI, 0.05-0.84; P=0.02), PFS (HR, 0.30; 95% CI, 0.13-0.70; P=0.003), and the ORR (P=0.001). CONCLUSIONS: We developed and validated a new LAF-bTMB algorithm as a feasible predictor of OS, PFS, and the ORR following anti-PD-1/PD-L1 therapies in NSCLC patients, which needs to be prospectively validated.

6.
J Phys Condens Matter ; 32(14): 145001, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31855858

RESUMO

Interface adhesion and stability between titanium and carbon materials have been investigated by first-principles calculation, in which three different DFT-PBE, DFT-LDA and optB88-vdW approaches are considered. Our calculation reveals that the formation of carbon vacancy in graphene would enhance the interface stability and increase interfacial strength, which may be due to a strong hybridization between titanium atom and the sp2 dangling bonds of the carbons near the vacancy. It is also found that the van der Waals interaction has less effects on cohesion properties of the titanium/graphite interfaces, and the Ti-C bond of titanium-carbon interfaces is weaker than that of the TiC bulk. The derived results are discussed in depth by means of electron distribution and Bader transfer analysis, and could be used as a guiding parameter for exploring the fundamental properties of titanium-carbon products as well as various potential applications.

7.
Cell Rep ; 29(8): 2489-2504.e4, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31747615

RESUMO

Hair follicle stem cells (HFSCs) and subsequent generations of matrix progeny make lineage choices by responding to spatiotemporal signals; however, the cues driving that specification are not well understood. Here, we demonstrate that the dynamics of microRNA (miR)-29 expression are inversely proportional to HFSC lineage progression. Furthermore, we show that sustained miR-29a/b1 overexpression in anagen or telogen in mice causes a short-hair phenotype and eventual hair loss by inhibiting the proliferation of HFSCs and matrix cells and likely preventing their differentiation. Conversely, in a loss-of-function in vivo model, miR-29a/b1 deficiency accelerates HFSC lineage progression in telogen. Mechanistically, miR-29a/b1 blocks HFSC lineage specification by spatiotemporally targeting Ctnnb1, Lrp6, Bmpr1a, and Ccna2. We further show that skin-specific Lrp6 or Bmpr1a ablation partially accounts for the short-hair phenotype. Overall, these synergistic targets reveal miR-29a/b1 as a high-fidelity antagonist of HFSC lineage progression and a potential therapeutic target for hair loss.

8.
Nat Commun ; 10(1): 5076, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31700061

RESUMO

Previous studies from the Cancer Cell Line Encyclopedia (CCLE) project have adopted commercial pan-cancer cell line models to identify drug sensitivity biomarkers. However, drug sensitivity biomarkers in esophageal squamous cell carcinoma (ESCC) have not been widely explored. Here, eight patient-derived cell lines (PDCs) are successfully established from 123 patients with ESCC. The mutation profiling of PDCs can partially recapture the tumor tissue actionable mutations from 161 patients with ESCC. Based on these mutations and relative pathways in eight PDCs, 46 targeted drugs are selected for screening. Interestingly, some drug and biomarker relationships are established that were not discovered in the CCLE project. For example, CDKN2A or CDKN2B loss is significantly associated with the sensitivity of CDK4/6 inhibitors. Furthermore, both PDC xenografts and patient-derived xenografts confirm CDKN2A/2B loss as a biomarker predictive of CDK4/6 inhibitor sensitivity. Collectively, patient-derived models could predict targeted drug sensitivity associated with actionable mutations in ESCC.

9.
Theranostics ; 9(26): 8182-8195, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31754389

RESUMO

Zinc-finger and BTB/POZ domain-containing family proteins (ZBTB) are important transcription factors functioning as tumor suppressors or oncogenes, such as BCL6/ZBTB27 as a key oncoprotein for anti-cancer therapy. Through epigenome study, we identified ZBTB28/BCL6B/BAZF, a BTB/POZ domain protein highly homologous to BCL6, as a methylated target in multiple tumors. However, the functions and mechanism of ZBTB28 in carcinogenesis remain unclear. Methods: ZBTB28 expression and methylation were examined by reverse-transcription PCR and methylation-specific PCR. The effects and mechanisms of ectopic ZBTB28 expression on tumor cells were assessed with molecular biological and cellular approaches in vitro and in vivo. Results: Albeit broadly expressed in multiple normal tissues, ZBTB28 is frequently downregulated in aero- and digestive carcinoma cell lines and primary tumors, and correlated with its promoter CpG methylation status. Further gain-of-function study showed that ZBTB28 functions as a tumor suppressor inhibiting carcinoma cell growth in vitro and in vivo, through inducing cell cycle arrest and apoptosis of tumor cells. ZBTB28 suppresses cell migration and invasion by reversing EMT and cell stemness. ZBTB28 transactivates TP53 expression, through binding to the p53 promoter in competition with BCL6, while BCL6 itself was also found to be a direct target repressed by ZBTB28. Conclusion: Our results demonstrate that ZBTB28 functions as a tumor suppressor through competing with BCL6 for targeting p53 regulation. This newly identified ZBTB28/BCL6/p53 regulatory axis provides further molecular insight into carcinogenesis mechanisms and has implications in further improving BCL6-based anticancer therapy.

10.
Nat Commun ; 10(1): 4576, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31594952

RESUMO

Single-cell ATAC-seq (scATAC-seq) profiles the chromatin accessibility landscape at single cell level, thus revealing cell-to-cell variability in gene regulation. However, the high dimensionality and sparsity of scATAC-seq data often complicate the analysis. Here, we introduce a method for analyzing scATAC-seq data, called Single-Cell ATAC-seq analysis via Latent feature Extraction (SCALE). SCALE combines a deep generative framework and a probabilistic Gaussian Mixture Model to learn latent features that accurately characterize scATAC-seq data. We validate SCALE on datasets generated on different platforms with different protocols, and having different overall data qualities. SCALE substantially outperforms the other tools in all aspects of scATAC-seq data analysis, including visualization, clustering, and denoising and imputation. Importantly, SCALE also generates interpretable features that directly link to cell populations, and can potentially reveal batch effects in scATAC-seq experiments.

11.
Materials (Basel) ; 12(17)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480666

RESUMO

In this study, we proposed a novel and facile method to modify the surface of TiO2 nanoparticles and investigated the influence of the surface-modified TiO2 nanoparticles as an additive in a polyurethane (PU) coating. The hyperbranched polymers (HBP) were grafted on the surface of TiO2 nanoparticles via the thiol-yne click chemistry to reduce the aggregation of nanoparticles and increase the interaction between TiO2 and polymer matrices. The grafting of HBP on the TiO2 nanoparticles surface was investigated by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and thermogravimetry analysis (TGA). The thermal and mechanical properties of nanocomposite coatings containing various amounts of TiO2 nanoparticles were measured by dynamic mechanical thermal (DMTA) and tensile strength measurement. Moreover, the surface structure and properties of the newly prepared nanocomposite coatings were examined. The experimental results demonstrate that the incorporation of the surface-modified TiO2 nanoparticles can improve the mechanical and thermal properties of nanocomposite coatings. The results also reveal that the surface modification of TiO2 with the HBP chains improves the nanoparticle dispersion, and the coating surface shows a lotus leaf-like microstructure. Thus, the functional nanocomposite coatings exhibit superhydrophobic properties, good photocatalytic depollution performance, and high stripping resistance.

12.
Medicine (Baltimore) ; 98(32): e15837, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31393341

RESUMO

Peripherally inserted central catheters (PICCs) can provide nutritional and medical support for very low birth weight or critically ill newborns. The aim of this study was to retrospectively analyze the use of PICCs in our clinic for critically ill newborns to evaluate the relationship between catheter related factors and the occurrence of complications.Retrospective analysis was conducted for all newborns consecutively admitted at the Neonatal Intensive Care Unit (NICU), Chongqing Health Center for Women and Children, who underwent PICC insertion between May 2011 and March 2018. Data collected included total puncture success rate, one puncture success rate, infection rate, complication rate, unplanned catheter withdrawal rate, device days, and catheter indwelling time.Five-hundred eighty-eight infants (304 males and 284 females) aged 3.4 ±â€Š3.9 days, mean gestational age of 30.9 ±â€Š2.7 weeks and a mean body mass of 1.38 ±â€Š0.47 kg at insertion were included. Total puncture success rate was 99.65%, one puncture success rate was 77.77%. The mean catheter retention was 13.6 ±â€Š6.7 days: more than 30 days in 15 (2.61%) cases, 20 to 30 days in 60 (10.43%) cases, 10 to 19 days in 372 (64.70%) cases, and 62 days in 1 case. Complications occurred in 63 (10.71%) cases: with PICC insertion within 24 hours after birth in 29 (15.43%), within 48 hours in 13 (6.63%), and after 48 hours in 21 (10.99%) cases. Catheter tip culture was positive in 3 cases and there was 1 case of catheter-related bloodstream infection.Nursing measures of the maintenance of body temperature and the evaluation of blood vessels were important conditions for improving the success rate of one puncture in critically ill neonates. PICC catheterization as early as 48 hours will not increase the difficulty of PICC puncture. Nor did it increase the incidence of PICC complications.


Assuntos
Cateterismo Periférico/estatística & dados numéricos , Cateteres de Demora/estatística & dados numéricos , Estado Terminal , Unidades de Terapia Intensiva Neonatal/estatística & dados numéricos , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/prevenção & controle , Cateteres de Demora/efeitos adversos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Masculino , Estudos Retrospectivos
13.
Biol Reprod ; 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31365051

RESUMO

A number of genes relevant for sex determination have been found in species with temperature-dependent sex determination (TSD). Epigenetics play a key role in sex determination, but characterization of DNA methylation of sex-related genes on TSD remains unclear. Mauremys reevesii is a typical species with TSD. In this study, we analyzed the CpG methylation status of the proximal promoters, the mRNA expression patterns and the correlation between methylation and expression levels of CYP19A1, FOXL2, DMRT1, SOX9, and AMH, which are key genes in sex determination in other species. We also analyzed the expression level of genes that encode enzymes involved in methylation and demethylation. The expression levels of CYP19A1 and FOXL2 at the female producing temperature (FPT) were higher than those at the male producing temperature (MPT); the expression levels of DMRT1, SOX9, and AMH were higher at MPT. The expression of some genes involved in methylation and demethylation is significantly different between MPT and FPT. The expression of mRNA of genes involved in DNA methylation and demethylation affected by temperature, together with other factors, may change the methylation level of the regulatory regions of sex-related genes, which may further lead to temperature-specific expression of sex-related genes, and eventually affect the differentiation of the gonads.

14.
J Ethnopharmacol ; 244: 112088, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31323299

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Cang-ai volatile oil (CAVO) is a traditional Chinese medicine (TCM) inhalational preparation for the treatment of some depressive and emotive disorders. AIM OF THE STUDY: This research aimed to evaluate the efficiency and possible mechanism of intranasal CAVO administration on depression in chronic unpredictable mild stress (CUMS)-induced rats compared to lavender volatile oil (LVO) treatment after CUMS exposure and bilateral olfactory bulb impairment (OBI) in rats. MATERIALS AND METHODS: Forty depressive-like model rats induced by CUMS were evaluated by the forced swim test (FST), open field test (OFT), and sucrose preference test (SPT). The model rats were divided into five groups: CUMS (n = 8), CAVOh + CUMS (n = 8), CAVOl + CUMS (n = 8), LVO + CUMS (n = 8), and OBI + CAVO + CUMS (n = 8). The CUMS-induced rats were treated for a period of 4 weeks. The other healthy rats were regarded as the control (CTR, n = 8) subjects. The levels of serotonin (5-HT) and dopamine (DA) and their respective metabolites homovanillic acid (HVA) and 5-hydroxyindol acetic acid (5-HIAA) were measured in brain tissue homogenates of CUMS-induced rats using enzyme-linked immunosorbent assay (ELISA). RESULTS: CAVO ameliorated depressive-like behaviors (p < 0.05). The levels of DA in the CUMS group were lower than those in the CTR and CAVOh groups (**p < 0.01 and *p < 0.05). The levels of HVA were lower in the CUMS group than in the CTR, LVO, OBI + CAVOh and CAVOh groups (**p < 0.01 and *p < 0.05) and lower in the OBI + CAVOh group than in the CAVOh group (**p < 0.01). The levels of 5-HT in the CUMS group were lower than those in the CTR and CAVOh groups (**p < 0.01). The levels of 5-HIAA were lower in the CUMS and OBI + CAVOh groups than in the CTR, LVO and CAVOh groups (**p < 0.01). CONCLUSIONS: CAVO can improve depressive-like behaviors concomitant with the regulation of DA and 5-HT metabolism in the brains of CUMS-induced rats.

15.
Cell Death Differ ; 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332295

RESUMO

Quiescent satellite cells (SCs) that are activated to produce numerous myoblasts underpin the complete healing of damaged skeletal muscle. How cell-autonomous regulatory mechanisms modulate the balance among cells committed to differentiation and those committed to self-renewal to maintain the stem cell pool remains poorly explored. Here, we show that miR-31 inactivation compromises muscle regeneration in adult mice by impairing the expansion of myoblasts. miR-31 is pivotal for SC proliferation, and its deletion promotes asymmetric cell fate segregation of proliferating cells, resulting in enhanced myogenic commitment and re-entry into quiescence. Further analysis revealed that miR-31 posttranscriptionally suppresses interleukin 34 (IL34) mRNA, the protein product of which activates JAK-STAT3 signaling required for myogenic progression. IL34 inhibition rescues the regenerative deficiency of miR-31 knockout mice. Our results provide evidence that targeting miR-31 or IL34 activities in SCs could be used to counteract the functional exhaustion of SCs in pathological conditions.

16.
Biol Pharm Bull ; 42(7): 1146-1154, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257291

RESUMO

Helicid (4-formylphenyl-O-ß-D-allopyranoside), an active component found in seeds from the Chinese herb Helicia nilagirica, has been reported to exert sedative, analgesic, hypnotic and antidepressant effects. The present study was designed to evaluate the antidepressant, learning and cognitive improvement effects of helicid in a chronic unpredictable mild stress (CUMS) model of depression in rats and to explore cAMP/protein kinase A (PKA)/cAMP response element-binding (CREB) signaling pathway. Sprague-Dawley rats were randomly assigned to six groups (n = 10): control; CUMS; CUMS + fluoxetine (5 mg/kg) and CUMS + helicid at 8, 16 and 32 mg/kg. All rats were subjected to 12 weeks of CUMS protocols and drug administration during the last 6 weeks of CUMS. Our results showed that helicid, at a dose of 32 mg/kg, significantly reversed decreases in body weight and sucrose consumption, increased the distance and number of crossings in the open-field test (OFT), reduced immobility times in the forced swimming test (FST) and improved spatial memory in the Morris water maze (MWM); all of these effects had been induced by CUMS paradigm. Immunohistochemistry showed that administration of helicid could promoted the proliferation of neurons in the hippocampal CA1 and dentate gyrus (DG) regions. CUMS rats treated with helicid had dramatically decreased protein levels of serotonin transporters (SERTs). In addition, CUMS resulted in a significant reduction in the expression of cAMP, PKA C-α and p-CREB, each of which were partially attenuated by helicid administration. These results indicated that helicid could improve depressive behaviors, learning and cognitive deficits and increase hippocampal neurogenesis, which may be mediated by the regulation of SERTs, activation of the cAMP/PKA/CREB signaling pathway and upregulation of p-CREB levels in hippocampal.


Assuntos
Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Benzaldeídos/farmacologia , Benzaldeídos/uso terapêutico , Depressão/tratamento farmacológico , Estresse Psicológico/tratamento farmacológico , Animais , Cognição/efeitos dos fármacos , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Depressão/metabolismo , Depressão/psicologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Hipocampo/fisiologia , Aprendizagem/efeitos dos fármacos , Masculino , Neurogênese/efeitos dos fármacos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Estresse Psicológico/metabolismo , Estresse Psicológico/psicologia
17.
World J Microbiol Biotechnol ; 35(7): 109, 2019 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-31280382

RESUMO

Echinocandin B (ECB) is an important lipohexapeptide used for chemical manufacture of the antifungal agent anidulafungin. Sterigmatocystin (ST) is a polyketide mycotoxin produced by certain species of Aspergillus such as Aspergillus delacroxii SIPIW15, which could produce both ECB and ST. However, the presence of the potent carcinogen ST will greatly affect the quality and safety of ECB production. Therefore, it is essential to eliminate the ST biosynthesis and increase ECB titers in Asp. delacroxii SIPIW15. In this study, the polyketide synthase gene (stcA) required for biosynthesis of ST and its flanking region in Asp. delacroxii SIPIW15 were cloned, sequenced and analyzed firstly. Based on Agrobacterium-mediated transformation, the ΔstcA mutant AMT-1 was obtained and its yield of ECB was increased by 40% without ST detected at the same time as compared to the original strain. The results of the fed-batch experiments showed that the ECB yield of the ΔstcA strain AMT-1 was increased to 2163 ± 31 mg/l and no ST was detected in the 50 l bioreactor. This work suggested that the ΔstcA strain AMT-1 has the potential for application in ECB production improvement, and more importantly, to eliminate ST-related environmental pollution in ECB fermentation industry.


Assuntos
Aspergillus/genética , Aspergillus/metabolismo , Equinocandinas/biossíntese , Equinocandinas/genética , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/genética , Genes Fúngicos/genética , Policetídeo Sintases/genética , Esterigmatocistina/biossíntese , Agrobacterium/genética , Anidulafungina , Antifúngicos , Sequência de Bases , Técnicas de Cultura Celular por Lotes , Reatores Biológicos , DNA Fúngico/isolamento & purificação , Fermentação , Engenharia Metabólica , Redes e Vias Metabólicas/genética , Metabolismo Secundário/genética , Transformação Genética
18.
Oncol Rep ; 42(2): 549-560, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31173267

RESUMO

Tissue sampling of biliary tract carcinomas (BTCs) for molecular characterization is challenging. The aim of this study was to investigate the possibility of identifying individual actionable mutations derived from bile cell­free DNA (cfDNA) using targeted deep sequencing. Ten BTC patients, four with gallbladder carcinomas and six with cholangiocarcinomas, were enrolled in the present study. Using targeted deep sequencing with a panel of 150 tumor­related genes, paired bile cfDNA and tumor DNA were analyzed for mutational variants individually and then compared. The present study, to the best of our knowledge, is the first to reveal that bile cfDNA is predominantly comprised of long DNA fragments, which is not the case for plasma cfDNA. Herein, paired bile cfDNA and tumors from ten BTC patients were examined using targeted deep sequencing. When comparing bile cfDNA and tumor DNA for single nucleotide variation (SNV)/insertion and deletion (Indel), the results using targeted deep sequencing revealed high sensitivity (94.7%) and specificity (99.9%). Additionally, the sensitivity of detecting a copy number variation (CNV) was 75.0%, with a specificity of 98.9%. When comparing two bile extraction methods, including percutaneous transhepatic cholangial drainage and operation, no significant difference in SNV/Indel or CNV detection sensitivity was noted. Moreover, when examining the tumor stage and incidence site, AJCC stage II and the distal bile duct both had significantly decreased CNV detection sensitivities. The present study revealed that targeted deep sequencing can reliably detect mutational variants within bile cfDNA obtained from BTC patients. These preliminary results may shed light on bile cfDNA as a promising liquid biopsy for BTC patients.


Assuntos
Neoplasias do Sistema Biliar/genética , Biomarcadores Tumorais/genética , Ácidos Nucleicos Livres/genética , Variações do Número de Cópias de DNA , DNA de Neoplasias/genética , Biópsia Líquida/métodos , Mutação , Adulto , Idoso , Neoplasias do Sistema Biliar/classificação , Neoplasias do Sistema Biliar/diagnóstico , Ácidos Nucleicos Livres/análise , DNA de Neoplasias/análise , Feminino , Seguimentos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
19.
Cells ; 8(5)2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31108937

RESUMO

ß-site APP-cleaving enzyme 1 (BACE1) initiates amyloid precursor protein (APP) cleavage and ß-amyloid (Aß) production, a critical step in the pathogenesis of Alzheimer's disease (AD). It is thus of considerable interest to investigate how BACE1 activity is regulated. BACE1 has its maximal activity at acidic pH and GFP variant-pHluorin-displays pH dependence. In light of these observations, we generated three tandem fluorescence-tagged BACE1 fusion proteins, named pHluorin-BACE1-mCherry, BACE1-mCherry-pHluorin and BACE1-mCherry-EGFP. Comparing the fluorescence characteristics of these proteins in response to intracellular pH changes induced by chloroquine or bafilomycin A1, we found that pHluorin-BACE1-mCherry is a better pH sensor for BACE1 because its fluorescence intensity responds to pH changes more dramatically and more quickly. Additionally, we found that (pro)renin receptor (PRR), a subunit of the v-ATPase complex, which is critical for maintaining vesicular pH, regulates pHluorin's fluorescence and BACE1 activity in pHluorin-BACE1-mCherry expressing cells. Finally, we found that the expression of Swedish mutant APP (APPswe) suppresses pHluorin fluorescence in pHluorin-BACE1-mCherry expressing cells in culture and in vivo, implicating APPswe not only as a substrate but also as an activator of BACE1. Taken together, these results suggest that the pHluorin-BACE1-mCherry fusion protein may serve as a useful tool for visualizing active/inactive BACE1 in culture and in vivo.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas Luminescentes/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Linhagem Celular Tumoral , Cloroquina/farmacologia , Feminino , Fluorescência , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Macrolídeos/farmacologia , Masculino , Camundongos , Receptores de Superfície Celular/metabolismo , Transfecção , ATPases Vacuolares Próton-Translocadoras/metabolismo
20.
Soft Matter ; 15(17): 3588-3594, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30964145

RESUMO

Fluorescent hydrogels have recently attracted great attention for medical diagnostics, bioimaging and environmental monitoring. However, additional phosphors or fluorophores are always required to label the hydrogels, and they suffer from marker bleaching, signal drifts, or information misrepresentation. Here we report autofluorescence that universally exists in carbonyl-containing hydrogels without any traditional fluorophore. The fluorescence is successfully employed to self-monitor the gelation process since the fluorescence signal is closely related to the internal structural change of the gels. The crosslinked structure is beneficial to the fluorescence efficiency. Specifically, the fluorescence intensity is amplified with decreasing water content of the gels. The system realizes aggregation-induced emission in a water-deficient environment. The fluorescence is quenched by the addition of some specific metal ions, which can realize the successfully erasure and rewriting of information under visible light and ultraviolet light respectively. We believe that the spontaneous fluorescence of a gel provides the most reliable basis for the detection of a gel structure and opens new prospects in the application of hydrogels.

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