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1.
Sensors (Basel) ; 23(4)2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36850779

RESUMO

Vibratory compaction status has a significant influence on the construction quality of subgrade engineering. This study carried out field experiments to study the propagation characteristics of the vertical vibration wave in the soil field along the traveling direction of the vibratory roller. The propagation coefficients of the peak acceleration at different positions and compacting rounds are compared in both the time and frequency domains. The compaction status is estimated in the form of dynamic modulus of deformation (Evd) obtained by plate load tests. The experiment results show that the propagation coefficient of peak acceleration is affected by the traveling speed, excitation amplitude, and frequency of the vibratory roller, as well as the compacting rounds. An exponential relationship between the wave amplitudes of the fundamental mode and higher-order modes is revealed. The amplitude of the fundamental wave is maximum at the speed of 3 km/h, whereas the amplitudes of higher-order waves have a maximum of 1.5 km/h. The influences of compaction rounds on the average value of Evd are also investigated to provide a practical reference for engineering construction.

2.
Hum Mol Genet ; 29(15): 2471-2480, 2020 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-32592472

RESUMO

Charcot-Marie-Tooth (CMT) disease is the most common inherited peripheral neuropathy and shows clinical and genetic heterogeneity. Mutations in C1orf194 encoding a Ca2+ regulator in neurons and Schwann cells have been reported previously by us to cause CMT disease. In here, we further investigated the function and pathogenic mechanism of C1or194 by generating C1orf194 knockout (KO) mice. Homozygous mutants of C1orf194 mice exhibited incomplete embryonic lethality, characterized by differentiation abnormalities and stillbirth on embryonic days 7.5-15.5. Heterozygous and surviving homozygous C1orf194 KO mice developed motor and sensory defects at the age of 4 months. Electrophysiologic recordings showed decreased compound muscle action potential and motor nerve conduction velocity in the sciatic nerve of C1orf194-deficient mice as a pathologic feature of dominant intermediate-type CMT. Transmission electron microscopy analysis revealed demyelination and axonal atrophy in the sciatic nerve as well as swelling and loss of mitochondrial matrix and other abnormalities in axons and Schwann cells. A histopathologic examination showed a loss of motor neurons in the anterior horn of the spinal cord and muscle atrophy. Shorter internodal length between nodes of Ranvier and Schmidt-Lanterman incisures was detected in the sciatic nerve of affected animals. These results indicate that C1orf194 KO mice can serve as an animal model of CMT with a severe dominant intermediate CMT phenotype that can be used to investigate the molecular mechanisms of the disease and evaluate the efficacy of therapeutic strategies.


Assuntos
Doença de Charcot-Marie-Tooth/genética , Deficiências do Desenvolvimento/genética , Fases de Leitura Aberta/genética , Natimorto/genética , Animais , Axônios/metabolismo , Doença de Charcot-Marie-Tooth/mortalidade , Doença de Charcot-Marie-Tooth/patologia , Deficiências do Desenvolvimento/patologia , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Knockout , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Mutação/genética , Bainha de Mielina/genética , Fenótipo , Células de Schwann/metabolismo , Células de Schwann/patologia , Nervo Isquiático/metabolismo , Nervo Isquiático/patologia
3.
Microb Pathog ; 173(Pt A): 105837, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36257566

RESUMO

Gamma-proteobacteria is a class of gram-negative opportunistic pathogens existing in the intestinal flora, often leading to diarrhea and intestinal infectious diseases, and plays an important role in maintaining intestinal homeostasis. Type III secretion system (T3SS), an important virulence system, is closely related to the adhesion and invasion and pathogenicity to host cells. Therefore, anti-virulence agents targeting T3SS are important strategies for controlling pathogenic infections. In this study, the anti-Salmonella T3SS active compounds neochebulagic acid (1), ellagic acid (2) and urolithin M5 (3) were isolated from seed extract of Terminalia citrina by activity-guided isolation method. Based on the fact that urolithins are the main and stable intestinal microbiota metabolites of hydrolysable tannins, we found that the metabolite urolithin B repressed translation and secretion of SipC through the Hha-H-NS-HilD-HilC-RtsA-HilA regulatory pathway. The results provide evidence for Terminalia seeds and ellagitannin-rich berries and nuts in regulating intestinal homeostasis and treating bacterial infection.


Assuntos
Terminalia , Sistemas de Secreção Tipo III , Sistemas de Secreção Tipo III/metabolismo , Regulação Bacteriana da Expressão Gênica , Salmonella typhimurium , Taninos Hidrolisáveis/farmacologia , Taninos Hidrolisáveis/metabolismo , Fatores de Transcrição/genética , Proteínas de Bactérias/genética
4.
Nat Chem Biol ; 14(9): 876-886, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30120361

RESUMO

Signals from 800 G-protein-coupled receptors (GPCRs) to many SH3 domain-containing proteins (SH3-CPs) regulate important physiological functions. These GPCRs may share a common pathway by signaling to SH3-CPs via agonist-dependent arrestin recruitment rather than through direct interactions. In the present study, 19F-NMR and cellular studies revealed that downstream of GPCR activation engagement of the receptor-phospho-tail with arrestin allosterically regulates the specific conformational states and functional outcomes of remote ß-arrestin 1 proline regions (PRs). The observed NMR chemical shifts of arrestin PRs were consistent with the intrinsic efficacy and specificity of SH3 domain recruitment, which was controlled by defined propagation pathways. Moreover, in vitro reconstitution experiments and biophysical results showed that the receptor-arrestin complex promoted SRC kinase activity through an allosteric mechanism. Thus, allosteric regulation of the conformational states of ß-arrestin 1 PRs by GPCRs and the allosteric activation of downstream effectors by arrestin are two important mechanisms underlying GPCR-to-SH3-CP signaling.


Assuntos
Regulação Alostérica , Arrestina/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais , Domínios de Homologia de src , Células Cultivadas , Células HEK293 , Humanos
5.
J Nat Prod ; 83(9): 2803-2808, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32915576

RESUMO

Polycyclic tetramate macrolactams (PoTeMs) are a group of hybrid PK-NRP natural products having a variable set of carbocyclic rings, a conserved assembly pathway, and diverse bioactivities. We report here the identification of seven new PoTeMs, clifednamides D-J (3-9), along with the known clifednamides A (1) and B (2) through rational pathway refactoring and heterologous expression. Remarkably, clifednamides D (3), G (6), and H (7) feature an unprecedented 27,28-seco skeleton. The cytotoxic activities of compounds 1-9 indicated that the hydroxy group of C-25, the methyl group of C-30, the inner five-membered ring, and the intact macrocycle are all critical for the activities. Meanwhile, the cytochrome P450 enzyme CftS023A and the hydroxylase CftS023E involved in oxidative tailoring of clifednamides were found to decorate the fused 5-6 bicyclic intermediates. Accordingly, the biosynthetic pathway for clifednamides was proposed.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/química , Streptomyces/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Vias Biossintéticas , Linhagem Celular Tumoral , Sistema Enzimático do Citocromo P-450/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Oxigenases de Função Mista/metabolismo , Estrutura Molecular , Oxirredução , Microbiologia do Solo , Streptomyces/metabolismo
6.
J Neurochem ; 148(4): 550-560, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30451284

RESUMO

Protein Phosphatase Mg2+ /Mn2+ -Dependent 1K (PPM1K),also named as PP2Cm or branched-chain α-ketoacid dehydrogenase complex phosphatase, is a member of the metal-dependent phosphatase family and an important metabolic regulator. Single nucleotide polymorphisms (SNPs) in PPM1K contributing to protein functional defects have been found to be associated with numerous human diseases, such as cardiovascular disease, maple syrup urine disease, type 2 diabetes, and neurological disease. PPM1K N94K is an identified missense mutant produced by one of the SNPs in the human PPM1K coding sequence. However, the effects of the N94K mutant on its activity and structural property have not been defined. Here, we performed a detailed enzymological study using steady-state kinetics in the presence of pNPP or phospho-peptide substrates and crystallographic analyses of the wild-type and N94K PPM1K. The PPM1K-N94K significantly impaired its Mg2+ -dependent catalytic activity and structural analysis demonstrated that the N94K mutation induced a conformational change in the key residue in coordinating the Mg2+ in the active site. Specifically, three Mg2+ were located in the active site of the PPM1K N94K instead of two Mg2+ in the PPM1K wild type. Therefore, our results provide a structure basis for the metal ion-dependent PPM1K-N94K phosphatase activity.


Assuntos
Proteína Fosfatase 2C/química , Proteína Fosfatase 2C/genética , Biocatálise , Humanos , Mutação , Relação Estrutura-Atividade
7.
Acta Pharmacol Sin ; 38(4): 524-538, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28260799

RESUMO

Bisindolylmaleimides, a series of derivatives of a PKC inhibitor staurosporine, exhibit potential as anti-cancer drugs and have received considerable attention in clinical trials. This study aims to investigate the effects of a bisindolylmaleimide alkaloid 155Cl (BMA-155Cl) with a novel structure on autophagy and apoptosis in human hepatocarcinoma HepG-2 cells in vitro and in vivo. The cell poliferation was assessed with a MTT assay. Autophagy was evaluated by MDC staining and TEM analysis. Apoptosis was investigated using Annexin V-FITC/PI and DAPI staining. The antitumor effects were further evaluated in nude mice bearing HepG-2 xenografts, which received BMA-155Cl (10, 20 mg/kg, ip) for 18 days. Autophagy- and apoptosis-associated proteins and their mRNA levels were examined with Western blotting, immunohistochemistry, and RT-PCR. BMA-155Cl (2.5-20 µmol/L) inhibited the growth of HepG-2 cells with IC50 values of 16.62±1.34, 12.21±0.83, and 8.44±1.82 µmol/L at 24, 48, and 72 h, respectively. Furthermore, BMA-155Cl (5-20 µmol/L) dose-dependently induced autophagy and apoptosis in HepG-2 cells. The formation of autophagic vacuoles was induced by BMA-155Cl (10 µmol/L) at approximately 6 h and peaked at approximately 15 h. Pretreatment with 3-MA potentiated BMA-155Cl-mediated apoptotic cell death. This compound dose-dependently increased the mRNA and protein levels of Beclin-1, NF-κB p65, p53, and Bax, but decreased the expression of IκB and Bcl-2. Pretreatment with BAY 11-7082, a specific inhibitor of NF-κB p65, blocked BMA-155Cl-induced expression of autophagy- and apoptosis-associated proteins. BMA-155Cl administration effectively suppressed the growth of HepG-2 xenografts in vivo, and increased the protein expression levels of LC3B, Beclin-1, NF-κB p65, and Bax in vivo. We conclude that the NF-κB p65 pathway is involved in BMA-155Cl-triggered autophagy, followed by apoptosis in HepG-2 cells in vitro and in vivo. Hence, BMA-155Cl could be a promising pro-apoptotic candidate for developing as a novel anti-cancer drug.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Alcaloides Indólicos/uso terapêutico , Indóis/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Maleimidas/uso terapêutico , Animais , Proteína Beclina-1/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Células Hep G2 , Humanos , Proteínas I-kappa B/metabolismo , Alcaloides Indólicos/farmacologia , Indóis/farmacologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Maleimidas/farmacologia , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Associadas aos Microtúbulos/metabolismo , Transplante de Neoplasias , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Transdução de Sinais , Fator de Transcrição RelA/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
8.
Bioorg Med Chem ; 24(9): 2125-36, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27039251

RESUMO

As our ongoing work on research of gelatinase inhibitors, an array of hydrazide-containing peptidomimetic derivatives bearing quinoxalinone as well as spiro-heterocyclic backbones were designed, synthesized, and assayed for their in vitro enzymatic inhibitory effects. The results demonstrated that both the quinoxalinone (series I and II) and 1,4-dithia-7-azaspiro[4,4]nonane-based hydrazide peptidomimetics (series III) displayed remarkably selectivity towards gelatinase A as compared to APN, with IC50 values in the micromole range. Structure-activity relationships were herein briefly discussed. Given evidences have validated that gelatinase inhibition may be contributable to the therapy of HIV-1 infection, all the target compounds were also submitted to the preliminary in vitro anti-HIV-1 evaluation. It resulted that gelatinase inhibition really has positive correlation with anti-HIV-1 activity, especially compounds 4m and 7h, which gave enhanced gelatinase inhibition in comparison with the positive control LY52, and also decent anti-HIV-1 potencies. The FlexX docking results provided a straightforward insight into the binding pattern between inhibitors and gelatinase, as well as the selective inhibition towards gelatinase over APN. Collectively, our research encouraged potent gelatinase inhibitors might be used in the development of anti-HIV-1 agents. And else, compounds 4m and 7h might be promising candidates to be considered for further chemical optimization.


Assuntos
Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/farmacologia , Azidas/farmacologia , Gelatinases/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Peptidomiméticos , Fármacos Anti-HIV/química , Desenho de Fármacos
9.
Beilstein J Org Chem ; 10: 858-862, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24778741

RESUMO

Two pairs of geometrical isomers - cuevaenes A (1) and C (3) as well as cuevaenes D (4) and E (5) - and cuevaene B (2) were isolated from gdmAI-disrupted Streptomyces sp. LZ35. The constitution of cuevaene C (3) was found to be identical to cuevaene A (1) by means of NMR spectroscopy and high resolution mass spectrometry. However, the relative configurations of the triene side chain moieties were determined to be different. It was established on the basis of spectroscopic data that cuevaenes D (4) and E (5) are amides and geometrical isomers. Cuevaenes A-C (1-3) displayed moderate activity against Gram-positive bacteria (e.g., Bacillus subtilis strain ATCC 11060) and modest activity against fungi (e.g., Fusarium verticillioides strain S68 and Rhizoctonia solani strain GXE4). However, cuevaenes D (4) and E (5) showed no inhibitory activity against any of the tested microbes.

10.
Sci Rep ; 14(1): 12504, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38821989

RESUMO

To systematically analyze the damage caused by bedrock and overburden layer slope under seismic action, a set of large-scale shaking table test was designed and completed. Interpolation of the acceleration amplification coefficient, Hilbert-Huang transform and transfer function was adopted. The damage mechanisms of the bedrock and overburden layer slopes under seismic action are systematically summarized in terms of slope displacement, acceleration field, vibration amplitude, energy, vibration frequency, and damage level. The results show a significant acceleration amplification effect within the slope under seismic action and a localized amplification effect at the top and trailing edges of the slope. With an increase in the input seismic intensity, the difference in the vibration amplitude between the overburden layer and bedrock increased, low-frequency energy of the overburden layer was higher than that of the bedrock, and the vibration frequency of the overburden layer was smaller than that of the bedrock. These differences cause the interface to experience cyclic loading continuously, resulting in the damage degree of the overburden layer at the interface being larger than that of the bedrock, reduction of the shear strength, and eventual formation of landslides. The displacement in the middle of the overburden is always greater than that at the top. Therefore, under the action of an earthquake and gravity, the damage mode of the bedrock and overburden layer slope is such that the leading edge of the critical part pulls and slides at the trailing edge, and multiple tensile cracks are formed on the slope surface.

11.
J Asian Nat Prod Res ; 14(7): 613-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22574939

RESUMO

Two new and three known abscisic acid-related metabolites were obtained from the potato dextrose agar culture of Phellinus vaninii YB2005. Their structures were established on the basis of detailed spectroscopic analyses, including 1D NMR, 2D NMR, and HR-Q-TOF-MS techniques. The putative biosynthesis pathway of these secondary metabolites would decipher the mechanism of the symbiosis between plant and fungi from the view of chemistry.


Assuntos
Ácido Abscísico , Basidiomycota/química , Ácido Abscísico/análogos & derivados , Ácido Abscísico/química , Ácido Abscísico/isolamento & purificação , Ácido Abscísico/metabolismo , China , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular
12.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 24(11): 655-7, 2012 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-23131282

RESUMO

OBJECTIVE: To investigate the characteristics of the confined space accident and its medical rescue strategy. METHODS: Thirty-six patients with emergency rescue in the five confined space accident during June 2009 to July 2012 were retrospectively analyzed. RESULTS: Twenty-nine people were caught in four confined space accidents caused by building collapse and 7 people were caught in one confined space accident caused by a tower of babel blast furnace damage which caused severe gas and hydrogen sulfide poisoning. For the 36 wounded, the shortest rescue time was 1.5 hours and the longest was 10.5 hours. Fourteen people were killed (mortality rate 38.89%). Characteristics of the confined space accident: the wounded activity environment was very harsh, the wounded were restricted particularly, the wounded injuries were diverse, the psychological depression was very common. The confined space environment and the complexity of wounded disease determined its medical rescue specificity and were very different from the usual trauma emergency. CONCLUSIONS: Confined space accident caused very painful casualties. The key reason is that the relevant personnel failed to clearly recognize the potential risks in the confined space or nearby, making the confined space into another "quiet killer". This problem needs to be paid highly attention.


Assuntos
Acidentes , Espaços Confinados , Desastres/prevenção & controle , Emergências , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
13.
Dev Growth Differ ; 53(3): 312-22, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21447096

RESUMO

The human telomerase reverse transcriptase (hTERT) gene has been used to stimulate the proliferation of most types of human cells. The present study was designed to evaluate the feasibility and efficiency of adenovirus-mediated hTERT in the proliferation of bovine mammary gland epithelial cells (bMGEs). A plasmid and an adenovirus vector that carried hTERT, namely pEGFP- hTERT and Ad- hTERT, were constructed and transfected into bMGEs, respectively. In order to select the best strategy for stimulating cell proliferation, the adenovirus- and plasmid-mediated hTERT were compared in terms of the positive cloning and transgenic efficiency. The results showed that only Ad- hTERT had high infection efficiency and produced a positive polyclone population (hTERT-bMGEs). The characteristics of the hTERT-bMGEs were investigated with further analysis by reverse transcription-polymerase chain reaction (RT-PCR), western blotting, proliferation assays, and flow cytometry, which showed that hTERT facilitated strong cell proliferation. Real-time quantitative PCR showed a normal level of expression of beta-casein, the caspase-8 and c-myc proto-oncogene, and immunofluorescence demonstrated the properties of the epithelial cells. In conclusion, the adenovirus-mediated hTERT gene could not only extend the cell lifespan, but also maintained the primary characteristics of the cells. It may be possible to extend the use of a wide variety of non-human mammalian cells in this way. This study has provided additional insight into the mechanism of cell proliferation by demonstrating the lack of integration of the adenovirus-mediated hTERT gene into the mammalian genome.


Assuntos
Adenoviridae , Antígenos de Diferenciação/metabolismo , Proliferação de Células , Glândulas Mamárias Animais/metabolismo , Telomerase/biossíntese , Animais , Antígenos de Diferenciação/genética , Bovinos , Células Cultivadas , Feminino , Humanos , Glândulas Mamárias Animais/citologia , Gravidez , Proto-Oncogene Mas , Telomerase/genética , Transdução Genética
14.
Cell Biol Int ; 35(8): 789-92, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21244367

RESUMO

The aims of this study were to determine whether stem cells could be isolated from amniotic fluid of goat fetus at terminal gestational age and to determine if these stem cells could differentiate into adipogenic cells and be transfected with a reporter gene, EGFP (enhanced green fluorescent protein). The stem cells were isolated from amniotic fluid of goat fetus at terminal gestational age, induced to differentiate into adipogenic cells in vitro and transfected with the EGFP gene using lipofection. Markers associated with undifferentiated AFS (amniotic fluid-derived stem) cells were tested by RT (reverse transcription)-PCR. The results demonstrated that AFS cells could be isolated from amniotic fluid of goat fetus at terminal gestational age and could differentiate into adipogenic cells. The EGFP gene was transfected into AFS cells successfully. EGFP gene transfection efficiency of the three groups of transgenic AFS cells were 26.0, 29.9 and 30.5%, respectively. Both transgenic and wild-type AFS cells could express Hes1 (hairy and enhancer of split 1), Oct4 (octamer-binding protein 4) and Nanog.


Assuntos
Adipócitos/metabolismo , Líquido Amniótico/metabolismo , Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/metabolismo , Proteínas de Fluorescência Verde/genética , Adipócitos/citologia , Líquido Amniótico/citologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Biomarcadores , Proteínas de Ligação a DNA/biossíntese , Células-Tronco Embrionárias/citologia , Feminino , Idade Gestacional , Cabras , Proteínas de Homeodomínio/biossíntese , Fator 3 de Transcrição de Octâmero/biossíntese , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
15.
Cell Biol Int ; 35(12): 1243-6, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21605083

RESUMO

We have isolated stem cells from amniotic fluid of goat at terminal gestational age and transferred the EGFP (enhanced green fluorescent protein) gene into the stem cells previously. The aim of this study was to determine whether the transgenic stem cells have the capability of multipotent differentiation. The transgenic stem cells were induced to differentiate into neurogenic, adipogenic, osteogenic and endothelial cells in vitro. Markers associated with AFS (amniotic fluid-derived stem) cells and the differentiated cells were tested by RT-PCR (reverse transcription-PCR). The results demonstrated that the transgenic AFS cells were capable of self-renewal, a defining property of stem cells. AFS cells were positive for the undifferentiated cell markers, Oct4, Nanog, Sox2 and Hes1, while following differentiation cells expressed markers for neurogenic cells such as astrocyte [GFAP (glial fibrillary acidic protein)] and NSE (neuron-specific enolase), adipogenic cells [LPL+ (lipoprotein lipase+)], osteogenic cells (osteocalcin+ and osteonectin+) and endothelium [CD34+ and eNOS+ (endothelial nitric oxide synthase)]. The results demonstrated that the EGFP gene transgenic AFS cells have the capability of multipotent differentiation, which means that the transgenic AFS cells may be useful in cell-transplantation studies in future.


Assuntos
Líquido Amniótico/citologia , Diferenciação Celular , Proteínas de Fluorescência Verde/genética , Células-Tronco/citologia , Líquido Amniótico/metabolismo , Animais , Animais Geneticamente Modificados , Biomarcadores/metabolismo , Feminino , Cabras , Células-Tronco Multipotentes/citologia , Gravidez , Células-Tronco/metabolismo
16.
Cell Biol Int ; 35(8): 835-9, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21073446

RESUMO

We have obtained the EGFP (enhanced green fluorescence protein) gene transgenic porcine fetuses before. The aims of this study were (i) to determine whether stem cells could be isolated from amniotic fluid of the transgenic porcine fetuses, and (ii) to determine if these stem cells could express EGFP and differentiate in vitro. The results demonstrated that stem cells could be isolated from amniotic fluid of the EGFP gene transgenic porcine fetuses and could express EGFP and differentiate in vitro. Undifferentiated AFSs (amniotic fluid-derived stem cells) expressed POU5F1, THY1 and SOX2, while the following differentiation cells expressed markers for chondrogenic (COL2A1), osteogenic (osteocalcin and osteonectin) and neurogenic cells such as astrocyte (GFAP), oligodendrocyte (GALC) and neuron (NF, ENO2 and MAP).


Assuntos
Líquido Amniótico/citologia , Diferenciação Celular/fisiologia , Células-Tronco Embrionárias/citologia , Feto/citologia , Proteínas de Fluorescência Verde/biossíntese , Líquido Amniótico/metabolismo , Animais , Animais Geneticamente Modificados , Astrócitos/citologia , Astrócitos/metabolismo , Condrócitos/citologia , Condrócitos/metabolismo , Colágeno Tipo II/biossíntese , Células-Tronco Embrionárias/metabolismo , Feto/metabolismo , Galactosilceramidase/biossíntese , Proteínas de Fluorescência Verde/genética , Proteínas Quinases Ativadas por Mitógeno/biossíntese , Neurônios/citologia , Neurônios/metabolismo , Fator 3 de Transcrição de Octâmero/biossíntese , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteocalcina/biossíntese , Osteonectina/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/biossíntese , Suínos , Antígenos Thy-1/biossíntese
17.
Cell Biol Int ; 35(8): 849-56, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21391916

RESUMO

The aims of this study were (i) to determine whether NSCs (neural stem cells) could be isolated from the brain of embryonic day 98 fetal goat, (ii) to determine if these stem cells have the capability of multipotent differentiation following transfection with a reporter gene, EGFP (enhanced green fluorescent protein) and (iii) to study the characteristics of the stem cells cultured in attached and non-attached plates. NSCs were isolated from embryonic day 98 fetal goat brain, transfected with EGFP gene using lipofection, and subcultured in attached and non-attached plates respectively. The transgenic stem cells were induced to differentiate into osteogenic and endothelial cells in vitro respectively. Markers associated with undifferentiated NSCs and their differentiated cells were tested by RT-PCR (reverse transcription-PCR). The results demonstrated that stem cells could be isolated from embryonic day 98 fetal goat brain, and EGFP gene could be transfected into the cells. The transgenic NSCs were capable of self-renewal, a defining property of stem cells, and were grown as free-floating neurospheres in non-attached plates. When the neurospheres were transferred and cultured in attached plates, cells migrate from the neurospheres and are grown as spindle cells. The stem cells were grown as quasi-circular cells when the single stem cells were cultured in attached plates. Both the NSCs cultured in non-attached and attached plates could express Hes1 (hairy and enhancer of split 1), Oct4 (octamer-binding protein 4), Nanog, Sox2 [SRY (sex-determining region Y)-box 2] and Nestin, while following differentiation cells expressed markers for osteogenic cells (Osteocalcin+ and Osteonectin+) and endothelium (CD34+ and eNOS+). The results demonstrated that the goat EGFP gene transgenic NSCs have the capability of multipotent differentiation, which means that the transgenic NSCs may be useful in cell transplantation studies in future.


Assuntos
Diferenciação Celular/genética , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Proteínas de Fluorescência Verde/genética , Células-Tronco Neurais/citologia , Animais , Antígenos CD34/biossíntese , Fatores de Transcrição Hélice-Alça-Hélice Básicos/biossíntese , Técnicas de Cultura de Células , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Cabras , Proteínas de Homeodomínio/biossíntese , Proteínas de Filamentos Intermediários/biossíntese , Lipossomos , Proteínas do Tecido Nervoso/biossíntese , Nestina , Células-Tronco Neurais/metabolismo , Óxido Nítrico Sintase Tipo III/biossíntese , Fator 3 de Transcrição de Octâmero/biossíntese , Osteocalcina/biossíntese , Osteonectina/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXB1/biossíntese , Transfecção , Transgenes
18.
Nucleic Acids Res ; 37(3): 832-48, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19095693

RESUMO

PRMT1, an arginine methyltransferase, plays an important role in numerous cellular processes. In this study, we demonstrate a feedback regulatory loop between PRMT1 and the orphan receptor TR3. Unlike another orphan receptor HNF4, TR3 is not methylated by PRMT1 although they physically interact with each other. By delaying the TR3 protein degradation, PRMT1 binding leads to the elevation of TR3 cellular protein level, thereby enhances the DNA binding and transactivation activity of TR3 in a non-methyltransferase manner. Another coactivator SRC-2 acts synergistically with PRMT1 to regulate TR3 functions. In turn, TR3 binding to the catalytic domain of PRMT1 causes an inhibition of the PRMT1 methyltransferase activity. This repression results in the functional changes in some of PRMT1 substrates, including STAT3 and Sam68. The negative regulation of PRMT1 by TR3 was further confirmed in both TR3-knockdown cells and TR3-knockout mice with the use of an agonist for TR3. Taken together, our study not only identifies a regulatory role of PRMT1, independent on methyltransferase activity, in TR3 transactivation, but also characterizes a novel function of TR3 in the repression of PRMT1 methyltransferase activity.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Retroalimentação Fisiológica , Proteína-Arginina N-Metiltransferases/metabolismo , Receptores de Esteroides/metabolismo , Proteínas Repressoras/metabolismo , Animais , Linhagem Celular , Proteínas de Ligação a DNA/agonistas , Humanos , Camundongos , Camundongos Knockout , Coativador 2 de Receptor Nuclear/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Receptores de Esteroides/agonistas , Proteínas Repressoras/antagonistas & inibidores
19.
Phytochemistry ; 192: 112929, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34481176

RESUMO

From the aerial extracts of Coptosapelta diffusa (Champ. ex Benth.) Steenis, twenty-one compounds were isolated and identified by means of column chromatography and NMR and MS techniques, respectively. Amongst, ten ones were determined to be undescribed compounds including six seco-iridoid glucosides (1-6), 2-(hydroxymethyl)-1,2,3,4-tetrahydroanthracene-9,10-dione (7) and three guaiane-type sesquiterpenes (15-17). Compounds 7, 8 and 9 exhibited inhibitory activities against Staphylococcus aureus ATCC25923 with MIC of 8, 4 and 8 µg/mL. The use of 1-6 (iridoids), 7-14 (anthraquinones) and 15-17 (sesquiterpenes) as chemotaxonomic markers for this species was evidenced. Structurally, 7-14 are similar to those anthraquinones isolated from other species of the family Rubiaceae, confirming their close phylogenetic relationship. Whereas, these iridoids and sesquiterpenes with unique structures provided chemotaxonomic evidence to support the genus Coptosapelta (the tribe Coptosapelteae) as a sister of the subfamily Rubioideae. These results contrast with the general producing tendency of indole alkaloids by the species of the subfamily Cinchonoideae, and merit chemotaxonomic significance for the delimitation of Coptosapelta.


Assuntos
Rubiaceae , Antraquinonas , Glucosídeos Iridoides , Iridoides , Filogenia , Extratos Vegetais
20.
J Cell Mol Med ; 14(9): 2281-91, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19538463

RESUMO

The macrolide compound MFTZ-1 has been identified as a novel topoisomerase II (Top2) inhibitor with potent in vitro and in vivo anti-tumour activities. In this study, we further examined the effects of MFTZ-1 on hypoxia-inducible factor-1α (HIF-1α) accumulation, vascular endothelial growth factor (VEGF) secretion and angiogenesis. MFTZ-1 reduced HIF-1α accumulation driven by hypoxia or growth factors in human cancer cells. Mechanistic studies revealed that MFTZ-1 did not affect the degradation of HIF-1α protein or the level of HIF-1α mRNA. By contrast, MFTZ-1 apparently inhibited constitutive and inducible activation of both phosphatidylinositol-3-kinase (PI3K)-Akt and p42/p44 mitogen-activated protein kinase (MAPK) pathways. Further studies revealed that MFTZ-1 abrogated the HIF-1α-driven increase in VEGF mRNA and protein secretion. MFTZ-1 also lowered the basal level of VEGF secretion. The results reveal an important feature that MFTZ-1 can reduce constitutive, HIF-1α-independent VEGF secretion and concurrently antagonize inducible, HIF-1α-dependent VEGF secretion. Moreover, MFTZ-1 disrupted tube formation of human umbilical vein endothelial cells (HUVECs) stimulated by hypoxia with low-concentration serum or by serum at normoxia, and inhibited HUVECs migration at normoxia. MFTZ-1 also prevented microvessel outgrowth from rat aortic ring. These data reflect the potent anti-angiogenesis of MFTZ-1 under different conditions. Furthermore, using specific small interfering RNA targeting Top2α or Top2-defective HL60/MX2 cells, we showed that MFTZ-1 affected HIF-1α accumulation and HUVECs tube formation irrelevant to its Top2 inhibition. Taken together, our data collectively reveal that MFTZ-1 reduces constitutive and inducible HIF-1α accumulation and VEGF secretion possibly via PI3K-Akt and MAPK pathways, eliciting anti-angiogenesis independently of its Top2 inhibition.


Assuntos
DNA Topoisomerases Tipo II/metabolismo , Eicosanoides/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Macrolídeos/farmacologia , Inibidores da Topoisomerase II/farmacologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Linhagem Celular Tumoral , Eicosanoides/uso terapêutico , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Macrolídeos/uso terapêutico , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neovascularização Patológica/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos
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