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1.
J Asian Nat Prod Res ; 25(11): 1051-1057, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37010914

RESUMO

Two new (1 and 2) meroterpenoids were isolated from the bark of Cinnamomum cassia. Their structures were determined by spectroscopic analyses and chemical methods. Antioxidant activities of 1 and 2 were evaluated by the ORAC and DPPH radical scavenging assays, and the results revealed that compound 2 displayed oxygen radical absorbance capacity. The discovery of compounds 1 and 2 added new members of this kind of natural product.


Assuntos
Cassia , Cinnamomum aromaticum , Cinnamomum aromaticum/química , Antioxidantes/farmacologia , Casca de Planta/química , Extratos Vegetais/química
2.
Bioeng Transl Med ; 8(2): e10455, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36925673

RESUMO

The intestinal flora has become very active in studies related to Parkinson's disease (PD) in recent years. The microbe-gut-brain axis is closely related to the maintenance of brain homeostasis as well as PD pathogenesis. Alterations in gut bacteria can contribute to neuroinflammation and dopamine (DA) neurodegeneration. Lactobacillus murinus, a gram-positive bacterium, is a commensal gut bacteria present in the mammalian gut and considered as a potential probiotic due to its beneficial effects, including anti-inflammatory and antibacterial actions. In this study, the effects of live L. murinus and heat-killed L. murinus on DA neuronal damage in rats and the underlying mechanisms were investigated. Data showed that heat-killed L. murinus ameliorated 6-hydroxydopamine-induced motor dysfunctions and loss of substantia nigra DA neurons, while no protection was shown in live L. murinus treatment. At the same time, heat-killed L. murinus reduced the activation of NLRP3 inflammasome in microglia and the secretion of pro-inflammatory factors, thus inhibiting the development of neuroinflammation. Furthermore, heat-killed L. murinus failed to display its original neuroprotective properties in NLRP3 inflammasome knockout mice. Together, heat-killed L. murinus conferred neuroprotection against DA neuronal loss via the inhibition of microglial NLRP3 inflammasome activation. These findings provide a promising potential for future applications of L. murinus, and also beneficial strategy for PD treatment.

3.
CNS Neurosci Ther ; 28(11): 1675-1688, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35822696

RESUMO

There might be more than 10 million confirmed cases of Parkinson's disease (PD) worldwide by 2040. However, the pathogenesis of PD is still unclear. Host health is closely related to gut microbiota, which are affected by factors such as age, diet, and exercise. Recent studies have found that gut microbiota may play key roles in the progression of a wide range of diseases, including PD. Changes in the abundance of gut bacteria, such as Helicobacter pylori, Enterococcus faecalis, and Desulfovibrio, might be involved in PD pathogenesis or interfere with PD therapy. Gut microbiota and the distal brain achieve action on each other through a gut-brain axis composed of the nervous system, endocrine system, and immune system. Here, this review focused on the current understanding of the connection between Parkinson's disease and gut microbiota, to provide potential therapeutic targets for PD.


Assuntos
Microbioma Gastrointestinal , Doença de Parkinson , Encéfalo/patologia , Microbioma Gastrointestinal/fisiologia , Humanos , Doença de Parkinson/tratamento farmacológico
4.
Front Pharmacol ; 13: 846541, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35586062

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder recognized as a global public health priority. Although available treatments temporarily relieve the symptoms, they could not prevent the progression of cognitive decline. Natural compounds have been rich sources for drug discovery. Dendrobium nobile Lindl. alkaloid (DNLA) is the main active compound in Dendrobium nobile Lindl, a traditional Chinese herbal medicine. Recent studies indicated that DNLA produced neuroprotection. However, the mechanisms underlying DNLA-generated neuroprotection remain unknown. To investigate neuroprotection and the underlying mechanisms of DNLA, mouse hippocampus injection of lipopolysaccharide (LPS)-induced neuronal damage was performed. DNLA protected hippocampus neurons and working memory disorder against LPS-induced neurotoxicity. In addition, DNLA suppressed cell undergoing membrane lysis and cell swelling and inhibited the essential mediator of pyroptosis GSDMD-N expressions. Furthermore, DNLA-mediated neuroprotection was dependent on the inhibition of NLRP3 inflammasome activation, as evidenced by the fact that DNLA reduced pro-inflammatory factor (IL-18 and IL-1ß) production and inhibited the expression of related proteins. DNLA-exerted neuroprotection against LPS-induced neuronal damage, and cognitive impairment was not observed in NLRP3 knockout mice. Together, this study suggested that DNLA attenuated NLRP3-mediated pyroptosis to generate neuroprotection against LPS-induced neuronal damage and cognitive impairment.

5.
Front Immunol ; 12: 683577, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248967

RESUMO

Dyskinesia is a serious complication of Parkinson's disease during levodopa (L-DOPA) treatment. The pathophysiology of L-DOPA-induced dyskinesia (LID) is complex and not fully illuminated. At present, treatment of dyskinesia is quite limited. Recent studies demonstrated neuroinflammation plays an important role in development of LID. Thus, inhibition of neuroinflammation might open a new avenue for LID treatment. Resveratrol (RES) is the most well-known polyphenolic stilbenoid and verified to possess a large variety of biological activities. DA neurotoxicity was assessed via behavior test and DA neuronal quantification. The movement disorders of dyskinesia were detected by the abnormal involuntary movements scores analysis. Effects of RES on glial cells-elicited neuroinflammation were also explored. Data showed that RES attenuated dyskinesia induced by L-DOPA without affecting L-DOPA's anti-parkinsonian effects. Furthermore, RES generated neuroprotection against long term treatment of L-DOPA-induced DA neuronal damage. Meanwhile, RES reduced protein expression of dyskinesia molecular markers, ΔFOS B and ERK, in the striatum. Also, there was a strong negative correlation between DA system damage and ΔFOS B level in the striatum. In addition, RES inhibited microglia and astroglia activation in substantia nigra and subsequent inflammatory responses in the striatum during L-DOPA treatment. RES alleviates dyskinesia induced by L-DOPA and these beneficial effects are closely associated with protection against DA neuronal damage and inhibition of glial cells-mediated neuroinflammatory reactions.


Assuntos
Discinesias/etiologia , Discinesias/fisiopatologia , Levodopa/efeitos adversos , Resveratrol/farmacologia , Animais , Biomarcadores , Modelos Animais de Doenças , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Discinesias/tratamento farmacológico , Discinesias/metabolismo , Masculino , Oxidopamina/efeitos adversos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/etiologia , Doença de Parkinson/fisiopatologia , Ratos , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Substância Negra/fisiopatologia
6.
World J Gastroenterol ; 27(1): 55-68, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33505150

RESUMO

BACKGROUND: Accumulating evidence has revealed that several long non-coding ribonucleic acids (lncRNAs) are crucial in the progress of hepatocellular carcinoma (HCC). AIM: To classify a long non-coding RNA, i.e., lncRNA W5, and to determine the clinical significance and potential roles of lncRNA W5 in HCC. METHODS: The results showed that lncRNA W5 expression was significantly downregulated in HCC cell lines and tissues. Analysis of the association between lncRNA W5 expression levels and clinicopathological features suggested that low lncRNA W5 expression was related to large tumor size (P < 0.01), poor histological grade (P < 0.05) and serious portal vein tumor thrombosis (P < 0.05). Furthermore, Kaplan-Meier survival analysis showed that low expression of lncRNA W5 predicts poor overall survival (P = 0.016). RESULTS: Gain-of-loss function experiments, including cell counting kit8 assays, colony formation assays, and transwell assays, were performed in vitro to investigate the biological roles of lncRNA W5. In vitro experiments showed that ectopic overexpression of lncRNA W5 suppressed HCC cell proliferation, migration and invasion; conversely, silencing of lncRNA W5 promoted cell proliferation, migration and invasion. In addition, acting as a tumor suppressor gene in HCC, lncRNA W5 inhibited the growth of HCC xenograft tumors in vivo. CONCLUSION: These results showed that lncRNA W5 is down-regulated in HCC, and it may suppress HCC progression and predict poor clinical outcomes in patients with HCC. LncRNA W5 may serve as a potential HCC prognostic biomarker in addition to a therapeutic target.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Prognóstico , RNA Longo não Codificante/genética
7.
Chem Asian J ; 15(14): 2038-2059, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32452162

RESUMO

Combustion of liquid fuels containing sulfur compounds is highly unfavorable due to the adverse effects caused by the resultant SOx emission. Consequently, catalytic and adsorptive materials having the capacity to eliminate the sulfur compounds from liquid fuels are very attractive. Hexagonal boron nitride (BN), with its interesting chemical and physical properties, finds applications in diverse fields, especially in energy and environmental applications. Recently, BN and BN-based materials have gained significant interest in emerging desulfurization processes such as oxidative desulfurization and adsorptive desulfurization. In this review, BN and BN-based materials are elaborately discussed in the context of their use in various desulfurization techniques. A brief description about the different desulfurization processes is provided at the outset. The relationship between the characteristics (the defects, morphology, porosity and surface area) of BN and desulfurization efficiency is also summarized. Furthermore, the mechanistic insights regarding the action of BN materials in the desulfurization processes are discussed. With this review, the synthetic strategies for designing the novel BN-based catalysts/adsorbents for the effective desulfurization of liquid fuels can be grasped.

8.
J Ultrasound Med ; 39(6): 1203-1211, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31891216

RESUMO

OBJECTIVES: By analyzing the B-mode ultrasound and color Doppler flow imaging characteristics of breast lymphoma (BL) and breast infiltrating ductal carcinoma (BIDC), we expected to discriminate these diseases. METHODS: Thirty-two patients with BL and 30 with BIDC confirmed pathologically were selected. The BL group was divided into nodular and diffuse groups. We analyzed and compared the general and imaging characteristics of the BL subgroups and the BIDC group. RESULTS: The mean maximum diameter of BL was 54.93 ± 43.74 cm, and that of BIDC was 23.90 ± 6.79 cm (P < .05). The differences between the nodular BL and BIDC groups in a circumscribed margin (60.00% versus 20.00%), calcification (20.00% versus 53.33%), aggregation characteristics (0.00% versus 53.33%), and density (73.33% versus 10.00%) were statistically significant (P < .05). The differences between the diffuse BL and BIDC groups in calcification (6.67% versus 53.33%), aggregation characteristics (6.67% versus 53.33%) and density (40.00% versus 10.00%) were statistically significant (P < .05). The difference in a circumscribed margin (60% versus 13.33%) between the BL subgroups was statistically significant (P < .05). The blood flow signal in BL lesions was richer than that in BIDC lesions (P < .05). CONCLUSIONS: Extrasuperior-quadrant single lesions in the BL group were larger than those in the BIDC group. The edges of the lesions in the nodular BL group were circumscribed and dense. Lesions in the diffuse BL group did not have a circumscribed margin, calcification, aggregation characteristics, or density. The blood flow signal in BL lesions was richer than that in BIDC lesions.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Ultrassonografia Mamária/métodos , Adulto , Idoso , Mama/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
9.
J Asian Nat Prod Res ; 22(8): 746-753, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31163996

RESUMO

Zeaxanthin dipalmitate (3) and two zeaxanthin dipalmitate derivatives, including one new compound (1), were obtained from wolfberry [the fruit of Lycium barbarum L. (Solanaceae)]. Their structures were unambiguously elucidated by spectroscopic analyses. Compound 2 is isolated from the genus Lycium for the first time, and its 1D/2D NMR data are firstly reported. All the compounds belong to carotenoids which are a kind of major bioactive constituents in wolfberry and are also responsible for wolfberry's red color.


Assuntos
Lycium , Frutas , Estrutura Molecular , Palmitatos , Xantofilas
11.
Chem Rec ; 20(6): 513-540, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31631504

RESUMO

Heterogeneous catalysis plays a key role in promoting green chemistry through many routes. The functionalizable reactive silanols highlight silica as a beguiling support for the preparation of heterogeneous catalysts. Metal active sites anchored on functionalized silica (FS) usually demonstrate the better dispersion and stability due to their firm chemical interaction with FSs. Having certain functional groups in structure, FSs can act as the useful catalysts for few organic reactions even without the need of metal active sites which are termed as the covetous reusable organocatalysts. Magnetic FSs have laid the platform where the effortless recovery of catalysts is realized just using an external magnet, resulting in the simplified reaction procedure. Using FSs of multiple functional groups, we can envisage the shortened reaction pathway and, reduced chemical uses and chemical wastes. Unstable bio-molecules like enzymes have been stabilized when they get chemically anchored on FSs. The resultant solid bio-catalysts exhibited very good reusability in many catalytic reactions. Getting provoked from the green chemistry aspects and benefits of FS-based catalysts, we confer the recent literature and progress focusing on the significance of FSs in heterogeneous catalysis. This review covers the preparative methods, types and catalytic applications of FSs. A special emphasis is given to the metal-free FS catalysts, multiple FS-based catalysts and magnetic FSs. Through this review, we presume that the contribution of FSs to green chemistry can be well understood. The future perspective of FSs and the improvements still required for implementing FS-based catalysts in practical applications have been narrated at the end of this review.

12.
Phytochemistry ; 164: 60-66, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31096077

RESUMO

Fifteen phenylpropanoid glycosides, including six undescribed compounds were isolated from the fruit of Lycium barbarum L. (Solanaceae) (goji or wolfberry). Their structures were identified by detailed spectroscopic analyses. Seven known compounds were firstly isolated from the genus Lycium, in which the 1D and 2D NMR data of one compound were reported for the first time. Notably, two undescribed compounds were a pair of rare tautomeric glycoside anomers characterized by the presence of free anomeric hydroxy. Antioxidant and hypoglycemic activities of all these compounds were assessed using DPPH radical scavenging, oxygen radical absorbance capacity (ORAC), and α-glucosidase inhibitory assays, respectively. These compounds showed different levels of oxygen radical absorbance capacity, and some isolates exhibited potent antioxidant activity with greater ORAC values than the positive control (EGCG).


Assuntos
Antioxidantes/farmacologia , Frutas/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Glicosídeos/farmacologia , Lycium/química , Fenilpropionatos/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Compostos de Bifenilo/antagonistas & inibidores , Relação Dose-Resposta a Droga , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Glicosídeos/química , Glicosídeos/isolamento & purificação , Conformação Molecular , Fenilpropionatos/química , Fenilpropionatos/isolamento & purificação , Picratos/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Relação Estrutura-Atividade , alfa-Glucosidases/metabolismo
13.
Life Sci ; 213: 9-17, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30308183

RESUMO

AIMS: To investigate the role and underlying mechanism of miR-185-5p in hepatitis B virus (HBV) expression and replication. MAIN METHODS: The relative levels of hepatitis B surface antigen and hepatitis B e antigen were detected by enzyme-linked immunosorbent assay (ELISA). The HBV DNA copies in the cultures medium were measured by RT-qPCR. The HBV large surface antigen promoter (S1p) activity was analyzed by luciferase reporter assay. The target relationship between miR-185-5p and ELK1 was identified by bioinformatics analysis and EGFP fluorescent reporter assay. The ELK1 expression was determined by RT-qPCR and Western blot. KEY FINDINGS: miR-185-5p significantly decreased HBV large surface antigen promoter activity and subsequently the production of HBV proteins and HBV DNA copies in vitro. Further, we identified the ETS transcription factor ELK1 is a target of miR-185-5p. Overexpression and knockdown experiments showed overexpression of ELK1 stimulated HBV large surface antigen promoter activity and promoted the production of HBV proteins and HBV DNA copies, whereas knockdown of ELK1 has the opposite effects. Moreover, the rescue of ELK1 expression reversed the suppression of miR-185-5p on HBV replication and gene expression. Further mechanistic study showed that the ETS binding sites within the HBV large surface antigen promoter are required for the repression effect of miR-185-5p on HBV. SIGNIFICANCE: There are few reports about the interaction between miRNAs and the transcription from HBV S1p, we found that miR-185-5p decreases HBV S1p activity by targeting ELK1, which may provide a promising therapeutic strategy for HBV infection.


Assuntos
Carcinoma Hepatocelular/virologia , Regulação Viral da Expressão Gênica , Vírus da Hepatite B/genética , Hepatite B/genética , Neoplasias Hepáticas/virologia , MicroRNAs/genética , Proteínas Elk-1 do Domínio ets/genética , Sítios de Ligação , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Replicação do DNA , DNA Viral/genética , DNA Viral/metabolismo , Células Hep G2 , Hepatite B/metabolismo , Hepatite B/virologia , Antígenos de Superfície da Hepatite B/metabolismo , Antígenos E da Hepatite B/metabolismo , Vírus da Hepatite B/metabolismo , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , Regiões Promotoras Genéticas , Replicação Viral/genética , Proteínas Elk-1 do Domínio ets/metabolismo
14.
J Nat Prod ; 80(11): 3010-3013, 2017 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-29099182

RESUMO

Houttuynoid M (1), a new houttuynoid, and the related known compound houttuynoid A (2) were isolated from Houttuynia cordata. Their structures were defined using NMR data analysis, HR-MSn experiment, and chemical derivatization. Houttuynoid M is the first example of a houttuynoid with a bis-houttuynin chain tethered to a flavonoid core. A putative biosynthetic pathway of houttuynoid M (1) is proposed. The anti-herpes simplex virus (anti-HSV) activities of 1 and 2 (IC50 values of 17.72 and 12.42 µM, respectively) were evaluated using a plaque formation assay with acyclovir as the positive control.


Assuntos
Antivirais/isolamento & purificação , Antivirais/farmacologia , Flavonoides/isolamento & purificação , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Houttuynia/química , Aciclovir/farmacologia , Aldeídos/química , Antivirais/química , Medicamentos de Ervas Chinesas/química , Flavonoides/química , Flavonoides/farmacologia , Glicosídeos/química , Estrutura Molecular
15.
Fitoterapia ; 122: 7-10, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28811187

RESUMO

A new asarone-derived racemate (1) was isolated from the rhizome of Acorus tatarinowii. The structure of 1 was established by comprehensive spectroscopic analyses, and it was successfully resolved by chiral HPLC, demonstrating that it is racemic. The absolute configurations of 1a [(-)-acortatarone A] and 1b [(+)-acortatarone A] were determined using quantum chemical calculations. Compounds 1a and 1b were the first cases of asarone derivatives with the 5,7-dialkyl-6-aryl-8-oxabicyclo[3.2.1]oct-3-en-2-one core. The α-glucosidase inhibitory and acetylcholinesterase (AChE) inhibitory activities of 1 were evaluated, and it exhibited α-glucosidase inhibitory activity with potency close to that of the positive control (acarbose).


Assuntos
Acorus/química , Anisóis/química , Inibidores de Glicosídeo Hidrolases/química , Rizoma/química , Acetilcolinesterase/metabolismo , Derivados de Alilbenzenos , Anisóis/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Estrutura Molecular , alfa-Glucosidases/metabolismo
16.
Xenobiotica ; 47(4): 284-289, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27237303

RESUMO

1. A filamentous fungus, Cunninghamella blakesleeana CGMCC 3.970, was applied as a microbial system to mimic mammalian metabolism of 4,5-dimethoxyl-canthin-6-one (1). Compound 1 belongs to canthin-6-one type alkaloids, which is a major bioactive constituent of a traditional Chinese medicine (the stems of Picrasma quassioides). 2. After 72 h of incubation in potato dextrose broth, 1 was metabolized to seven metabolites as follows: 4-methoxyl-5-hydroxyl-canthin-6-one (M1), 4-hydroxyl-5-methoxyl-canthin-6-one (M2), canthin-6-one (M3), canthin-6-one N-oxide (M4), 10-hydroxyl-4,5-dimethoxyl-canthin-6-one (M5), 1-methoxycarbonl-ß-carboline (M6), and 4-methoxyl-5-O-ß-D-glucopyranosyl-canthin-6-one (M7). 3. The structures of metabolites were determined using spectroscopic analyses, chemical methods, and comparison of NMR data with those of known compounds. Among them, M7 was a new compound. 4. The metabolic pathways of 1 were proposed, and the metabolic processes involved phase I (O-demethylation, dehydroxylation, demethoxylation, N-oxidation, hydroxylation, and oxidative ring cleavage) and phase II (glycosylation) reactions. 5. This was the first research on microbial transformation of canthin-6-one alkaloid, which could be a useful microbial model for producing the mammalian phase I and phase II metabolites of canthin-6-one alkaloids. 6. 1, M1-M5, and M7 are canthin-6-one alkaloids, whereas M6 belongs to ß-carboline type alkaloids. The strain of Cunninghamella blakesleeana can supply an approach to transform canthin-6-one type alkaloids into ß-carboline type alkaloids.


Assuntos
Biotransformação , Carbolinas/metabolismo , Cunninghamella/metabolismo , Alcaloides Indólicos/metabolismo
17.
Food Chem ; 214: 644-654, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27507521

RESUMO

Nine new phenylpropanoids, one new coumarin, and 43 known polyphenols were isolated from wolfberry. Their structures were determined by spectroscopic analyses, chemical methods, and comparison of NMR data. Polyphenols, an important type of natural products, are notable constituents in wolfberry. 53 polyphenols, including 28 phenylpropanoids, four coumarins, eight lignans, five flavonoids, three isoflavonoids, two chlorogenic acid derivatives, and three other constituents, were identified from wolfberry. Lignans and isoflavonoids were firstly reported from wolfberry. 22 known polyphenols were the first isolates from the genus Lycium. This research presents a systematic study on wolfberry polyphenols, including their bioactivities. All these compounds exhibited oxygen radical absorbance capacity (ORAC), and some compounds displayed DPPH radical scavenging activity. One compound had acetylcholinesterase inhibitory activity. The discovery of new polyphenols and their bioactivities is beneficial for understanding the scientific basis of the effects of wolfberry.


Assuntos
Flavonoides/análise , Sequestradores de Radicais Livres/química , Lycium/química , Polifenóis/análise , Acetilcolinesterase/química , Doença de Alzheimer , Benzotiazóis , Compostos de Bifenilo/química , Ácido Clorogênico/análise , Inibidores da Colinesterase/química , Análise de Alimentos/métodos , Radicais Livres/química , Lignanas/química , Estrutura Molecular , Oxigênio/química , Picratos/química , Extratos Vegetais/química , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade , Tiazóis/química
18.
Appl Microbiol Biotechnol ; 101(5): 2033-2041, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27858137

RESUMO

Psychrophilic enzymes display efficient activity at moderate or low temperatures (4-25 °C) and are therefore of great interest in biotechnological industries. We previously examined the crystal structure of BglU, a psychrophilic ß-glucosidase from the bacterium Micrococcus antarcticus, at 2.2 Å resolution. In structural comparison and sequence alignment with mesophilic (BglB) and thermophilic (GlyTn) counterpart enzymes, BglU showed much lower contents of Pro residue and of charged amino acids (particularly positively charged) on the accessible surface area. In the present study, we investigated the roles of specific amino acid residues in the cold adaptedness of BglU. Mutagenesis assays showed that the mutations G261R and Q448P increased optimal temperature (from 25 to 40-45 °C) at the expense of low-temperature activity, but had no notable effects on maximal activity or heat lability. Mutations A368P, T383P, and A389E significantly increased optimal temperature (from 25 to 35-40 °C) and maximal activity (~1.5-fold relative to BglU). Thermostability of A368P and A389E increased slightly at 30 °C. Mutations K163P, N228P, and H301A greatly reduced enzymatic activity-almost completely in the case of H301A. Low contents of Pro, Arg, and Glu are important factors contributing to BglU's psychrophilic properties. Our findings will be useful in structure-based engineering of psychrophilic enzymes and in production of mutants suitable for a variety of industrial processes (e.g., food production, sewage treatment) at cold or moderate temperatures.


Assuntos
Adaptação Fisiológica/genética , Proteínas de Bactérias/genética , Micrococcus/enzimologia , Micrococcus/metabolismo , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Sequência de Aminoácidos , Aminoácidos/genética , Proteínas de Bactérias/metabolismo , Temperatura Baixa , Estabilidade Enzimática , Micrococcus/genética , Mutagênese Sítio-Dirigida , Conformação Proteica , Alinhamento de Sequência
19.
Cancer Lett ; 382(2): 166-175, 2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-27597739

RESUMO

HBV infection has been reported to be closely associated with HCC development; however, the underlying mechanisms are unclear. Emerging evidence has indicated that long non-coding RNAs (lncRNAs) play important regulatory roles in the pathogenesis and progression of cancers. To investigate the important role and mechanism of lncRNAs in the progression of HBV-related HCC, we screened lncRNAs in HBV-positive and HBV-negative HCC tissues. We identified a novel lncRNA, lncRNA-Unigene56159, which is highly expressed in HBV-related HCC tissues, and further analysis showed that this lncRNA was induced by HBV in vitro. Functionally, Unigene56159 significantly promoted cell migration/invasion and epithelial-mesenchymal transition (EMT) in HCC. Mechanistically, Unigene56159 could directly bind to miR-140-5p and effectively act as a competing endogenous RNA (ceRNA) for miR-140-5p to de-repress the expression of the target gene Slug. Collectively, our findings indicate that the Unigene56159/miR-140-5p/Slug axis contributes to HCC cell migration and invasion, which may provide novel insights into the function of lncRNA-driven hepatocarcinogenesis.


Assuntos
Carcinoma Hepatocelular/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Movimento Celular , Transformação Celular Viral , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Hepatite B/complicações , Vírus da Hepatite B/patogenicidade , Interações Hospedeiro-Patógeno , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , MicroRNAs/genética , Invasividade Neoplásica , RNA Longo não Codificante/genética , Transdução de Sinais , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Transfecção
20.
J Transl Med ; 14(1): 189, 2016 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-27349221

RESUMO

BACKGROUND: Occurrence and progression of hepatocellular carcinoma (HCC) are associated with hepatitis B virus (HBV) infection. miR-1269b is up-regulated in HCC cells and tissues. However, the regulation of miR-1269b expression by HBV and the mechanism underlying the oncogenic activity of miR-1269b in HCC are unclear. METHODS: Reverse transcription quantitative PCR (RT-qPCR) was used to measure the expression of miR-1269b and target genes in HCC tissues and cell lines. Western blot analysis was used to assess the expression of miR-1269b target genes and related proteins. Using luciferase reporter assays and EMSA, we identified the factors regulating the transcriptional level of miR-1269b. Colony formation, flow cytometry and cell migration assays were performed to evaluate the phenotypic changes caused by miR-1269b and its target in HCC cells. RESULTS: We demonstrated that the expression levels of pre-miR-1269b and miR-1269b in HBV-positive HepG2.2.15 cells were dramatically increased compared with HBV-negative HepG2 cells. HBx was shown to facilitate translocation of NF-κB from the cytoplasm to the nucleus, and NF-κB binds to the promoter of miR-1269b to enhance its transcription. miR-1269b targets and up-regulates CDC40, a cell division cycle 40 homolog. CDC40 increases cell cycle progression, cell proliferation and migration. Rescue experiment indicated that CDC40 promotes malignancy induced by miR-1269b in HCC cells. CONCLUSION: We found that HBx activates NF-κB to promote the expression of miR1269b, which augments CDC40 expression, contributing to malignancy in HCC. Our findings provide insights into the mechanisms underlying HBV-induced hepatocarcinogenesis.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular/metabolismo , Movimento Celular/genética , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Fatores de Processamento de RNA/metabolismo , Transativadores/metabolismo , Regulação para Cima/genética , Regiões 3' não Traduzidas/genética , Sequência de Bases , Ciclo Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Fenótipo , Regiões Promotoras Genéticas , Ligação Proteica/genética , Transcrição Gênica , Proteínas Virais Reguladoras e Acessórias
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