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1.
Cell ; 161(4): 774-89, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25957685

RESUMO

We have ablated the cellular RNA degradation machinery in differentiated B cells and pluripotent embryonic stem cells (ESCs) by conditional mutagenesis of core (Exosc3) and nuclear RNase (Exosc10) components of RNA exosome and identified a vast number of long non-coding RNAs (lncRNAs) and enhancer RNAs (eRNAs) with emergent functionality. Unexpectedly, eRNA-expressing regions accumulate R-loop structures upon RNA exosome ablation, thus demonstrating the role of RNA exosome in resolving deleterious DNA/RNA hybrids arising from active enhancers. We have uncovered a distal divergent eRNA-expressing element (lncRNA-CSR) engaged in long-range DNA interactions and regulating IgH 3' regulatory region super-enhancer function. CRISPR-Cas9-mediated ablation of lncRNA-CSR transcription decreases its chromosomal looping-mediated association with the IgH 3' regulatory region super-enhancer and leads to decreased class switch recombination efficiency. We propose that the RNA exosome protects divergently transcribed lncRNA expressing enhancers by resolving deleterious transcription-coupled secondary DNA structures, while also regulating long-range super-enhancer chromosomal interactions important for cellular function.


Assuntos
Linfócitos B/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Regulação da Expressão Gênica , RNA Longo não Codificante/metabolismo , Animais , Células-Tronco Embrionárias/metabolismo , Elementos Facilitadores Genéticos , Instabilidade Genômica , Heterocromatina/metabolismo , Switching de Imunoglobulina , Cadeias Pesadas de Imunoglobulinas/genética , Camundongos , Sequências Reguladoras de Ácido Nucleico
2.
Plant Mol Biol ; 112(6): 293-307, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37507516

RESUMO

Long noncoding RNAs (lncRNAs) participate in plant biological processes under biotic and abiotic stresses. However, little is known about the function and regulation mechanism of lncRNAs related to the pathogen at a molecular level. A banana lncRNA, Malnc2310, is a Fusarium oxysporum f. sp. cubense inducible lncRNA in roots. In this study, we demonstrate the nuclear localization of Malnc2310 by fluorescence in situ hybridization and it can bind to several proteins that are related to flavonoid pathway, pathogen response and programmed cell death. Overexpression of Malnc2310 increases susceptibility to Fusarium crude extract (Fu), salinity, and cold in transgenic Arabidopsis. In addition, Malnc2310 transgenic Arabidopsis accumulated more anthocyanins under Fusarium crude extract and cold treatments that are related to upregulation of these genes involved in anthocyanin biosynthesis. Based on our findings, we propose that Malnc2310 may participate in flavonoid metabolism in plants under stress. Furthermore, phenylalanine ammonia lyase (PAL) protein expression was enhanced in Malnc2310 overexpressed transgenic Arabidopsis, and Malnc2310 may participate in PAL regulation by binding to it. This study provides new insights into the role of Malnc2310 in mediating plant stress adaptation.


Assuntos
Arabidopsis , Fusarium , Musa , RNA Longo não Codificante , RNA Longo não Codificante/genética , Fusarium/fisiologia , Musa/genética , Arabidopsis/genética , Antocianinas , Hibridização in Situ Fluorescente , Doenças das Plantas/genética , Misturas Complexas
3.
J Neuroinflammation ; 20(1): 55, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36864466

RESUMO

BACKGROUND: Periodontitis is closely associated with the pathogenesis of Alzheimer's disease (AD). Porphyromonas gingivalis (Pg), the keystone periodontal pathogen, has been reported in our recent study to cause immune-overreaction and induce cognitive impairment. Monocytic myeloid-derived suppressor cells (mMDSCs) possess potent immunosuppressive function. It is unclear whether mMDSCs-mediated immune homeostasis is impaired in AD patients with periodontitis, and whether exogenous mMDSCs could ameliorate immune-overreaction and cognitive impairment induced by Pg. METHODS: To explore the influence of Pg on cognitive function, neuropathology and immune balance in vivo, 5xFAD mice were treated with live Pg by oral gavage, three times a week for 1 month. The cells of peripheral blood, spleen and bone marrow from 5xFAD mice were treated with Pg to detect the proportional and functional alterations of mMDSCs in vitro. Next, exogenous mMDSCs were sorted from wild-type healthy mice and intravenously injected into 5xFAD mice that were infected with Pg. We used behavioral tests, flow cytometry and immunofluorescent staining to evaluate whether exogenous mMDSCs could ameliorate the cognitive function, immune homeostasis and reduce neuropathology exacerbated by Pg infection. RESULTS: Pg exacerbated cognitive impairment in 5xFAD mice, with the deposition of amyloid plaque and increased number of microglia in the hippocampus and cortex region. The proportion of mMDSCs decreased in Pg-treated mice. In addition, Pg reduced the proportion and the immunosuppressive function of mMDSCs in vitro. Supplement of exogenous mMDSCs improved the cognitive function, and enhanced the proportions of mMDSCs and IL-10+ T cells of 5xFAD mice infected with Pg. At the same time, supplement of exogenous mMDSCs increased the immunosuppressive function of endogenous mMDSCs while decreased the proportions of IL-6+ T cells and IFN-γ+ CD4+ T cells. In addition, the deposition of amyloid plaque decreased while the number of neurons increased in the hippocampus and cortex region after the supplement of exogenous mMDSCs. Furthermore, the number of microglia increased with an increase in the proportion of M2 phenotype. CONCLUSIONS: Pg can reduce the proportion of mMDSCs, induce immune-overreaction, and exacerbate the neuroinflammation and cognitive impairment in 5xFAD mice. Supplement of exogenous mMDSCs can reduce the neuroinflammation, immune imbalance and cognitive impairment in 5xFAD mice infected with Pg. These findings indicate the mechanism of AD pathogenesis and Pg-mediated promotion of AD, and provide a potential therapeutic strategy for AD patients.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Células Supressoras Mieloides , Animais , Camundongos , Monócitos , Doenças Neuroinflamatórias , Porphyromonas gingivalis , Placa Amiloide , Doença de Alzheimer/complicações
4.
Bioorg Med Chem ; 96: 117530, 2023 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-37956506

RESUMO

A number of NO-releasing quinoline derivatives have been designed and synthesized by introducing NO donor to quinoline carboxylic acid fragment. The anti-proliferation of all target compounds was evaluated against human cancer cell lines (HCT-116, MCF-7, and A549), MCF-7/ADR and normal cell (MCF-10A). Most compounds showed cytotoxic activity on cancer cells and drug-resistant cells with IC50 values in the range of 0.62-5.51 µM. Importantly, these compounds showed low toxicity to normal cells (4.21-34.08 µM). Further mechanism studies showed that the most potent compound 9 could release high concentration of NO and inhibit the activity of topoisomerase I. In addition, 9 regulated apoptosis-related proteins, generated ROS and blocked MCF-7 cells in G2/M phase to induce cell apoptosis. Furthermore, the P-gp-mediated transport was also influenced by 9. And 9 could significantly inhibit the growth of tumor in vivo without observable organ-related toxicities. Overall, as a novel NO-releasing quinoline derivative, 9 was worthy for further in-depth study.


Assuntos
Antineoplásicos , Neoplasias da Mama , Quinolinas , Humanos , Feminino , DNA Topoisomerases Tipo I/metabolismo , Neoplasias da Mama/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo , Apoptose , Quinolinas/farmacologia , Células MCF-7 , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Linhagem Celular Tumoral , Relação Estrutura-Atividade
5.
J Environ Manage ; 325(Pt A): 116499, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36257227

RESUMO

Over-compensatory growth of plants after disturbance is generally preferred by grassland users and managers because of more forage. How the grassland productivity and the plant growth condition before disturbance affect the compensatory growth are important for grazing management and the understanding of grassland degradation, yet they are not well understood. A clipping experiment was conducted on the Qinghai-Tibetan Plateau to understand the compensatory growth and conditions for the occurrence of over-compensatory at alpine meadows with different degradation status. Results showed the competition for light constrains the plant growth post-clipping at non-degraded and slightly degraded alpine meadows, while the reduction of soil nitrogen limits it at heavily degraded alpine meadow. The biomass accumulated post-clipping was positively correlated with the growing season biomass in unclipped plots and the biomass at clipping in clipped plots. When the aboveground biomass at clipping was less than 40.10 g m-2 and the growing season biomass was between 38 and 97 g m-2, the over-compensatory growth of alpine meadow could occur. Higher clipping rate is required for the alpine meadow with high productivity but the maximum clipping rate should be less than 0.71 to induce the over-compensatory growth. Equal-compensatory occurred at non-degraded and slightly degraded, while over-compensatory growth was observed at moderately degraded and a marginally significant over-compensatory growth at heavily degraded alpine meadow. The over-compensatory growth occurred at moderately degraded alpine meadow is mainly due to the performance of forbs. Our results suggest that grazing at moderately degraded alpine meadow may induce the over-compensatory growth at the community level, but the over-compensatory growth of forbs at moderately degraded alpine meadow may aggravate the alpine meadow degradation.


Assuntos
Pradaria , Solo , Tibet , Biomassa , Nitrogênio/análise , Plantas/metabolismo
6.
Nanotechnology ; 33(18)2022 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-35008071

RESUMO

ZnO quantum dots sensitized SnO2porous nanowires were fabricated and designed for UV excitation gas sensor. The ZnO/SnO2composite (SZQ1%) with the molar proportion of 1:100 exhibits excellent sensing properties to NO2gas under UV irradiation at 40 °C. The limits of detection of the SZQ1% sensor is 100 ppb. The humidity stability of SZQ1% was also measured and discussed by DC reversed circuit and complex impedance curves. The gas sensing mechanism is well discussed and illustrated to the ZnO quantum dots sensitized and the increased photo-generated carriers under UV irradiation.

7.
Phys Chem Chem Phys ; 24(22): 13935-13940, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35621118

RESUMO

We investigate the oxidation mechanism of the layered model system GeAs. In situ X-ray photoelectron spectroscopy experiments performed by irradiating an individual flake with synchrotron radiation in the presence of oxygen show that while As leaves the GeAs surface upon oxidation, a Ge-rich ultrathin oxide film is being formed in the topmost layer of the flake. We develop a theoretical model that supports the layer-by-layer oxidation of GeAs, with a logarithmic kinetics. Finally, assuming that the activation energy for the oxidation process changes linearly with coverage, we estimate that the activation energy for As oxidation is almost twice that for Ge at room temperature.

8.
J Nat Prod ; 85(5): 1282-1293, 2022 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-35536757

RESUMO

Gastric cancer (GC) is a common malignant disease worldwide, and finding novel agents and strategies for the treatment of GC are of urgent need. Celastrol (CEL) is a well-known natural product with antineoplastic activity. In this study, pyrazole analogues were introduced at the C-29 position of CEL. A total of 24 new derivatives were designed, synthesized, and evaluated for their mechanism and antitumor activity in vitro and in vivo. Among them, compound 21 exhibited the best activity against BGC-823 cells (IC50 = 0.21 ± 0.01 µM). Further biological studies showed that 21 significantly raised the reactive oxygen species (ROS) levels to activate the apoptotic pathway, causing mitochondrial dysfunction in BGC-823 cells. In addition, 21 also arrested cells in the G2/M phase to induce tumor cell apoptosis. In a nude mouse tumor xenograft model, 21 exhibited a better tumor inhibition rate (89.85%) than CEL (inhibition rate 76.52%). Taken together, the present study has provided an anticancer lead compound candidate, 21, and has revealed that increased ROS generation may be an effective strategy in the treatment of GC.


Assuntos
Antineoplásicos , Neoplasias Gástricas , Animais , Apoptose , Linhagem Celular Tumoral , Proliferação de Células , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imidazóis , Camundongos , Estrutura Molecular , Triterpenos Pentacíclicos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/tratamento farmacológico , Sulfonamidas , Tiofenos
9.
Bioorg Chem ; 111: 104867, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33845380

RESUMO

To enhance the disruption of Hsp90-Cdc37, we designed and synthesized a series (27) of CEL-triazole derivatives. Most of the target compounds showed enhanced anti-proliferative activity on four cancer cell lines (MDA-MB-231, MCF-7, HepG2 and A459). Among them, compound 6 showed the best anti-proliferation (IC50 = 0.34 ± 0.01 µM) on MDA-MB-231. Pharmacological studies had found that compound 6 showed a higher ability to disrupt Hsp90-Cdc37 interaction in cells and inhibited the expression of the key Hsp90-Cdc37 clients in a concentration-dependent manner. Further studies indicated that an enhanced covalent binding between compound 6 and thiols (cysteine) might be one of the reasons for the increased activity. Furthermore, compound 6 arrested cells in the G0/G1 phase and induced tumor cell apoptosis significantly. Overall, for cancer treatment, compound 6 was worth further exploring.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Ciclo Celular/antagonistas & inibidores , Chaperoninas/antagonistas & inibidores , Descoberta de Drogas , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas
10.
Bioorg Chem ; 111: 104903, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33894433

RESUMO

A series of dihydroartemisinin-cinnamic acid hybrids were designed, synthesized and evaluated. Most of the tested compounds showed enhanced anti-proliferative activities than artemisinin and dihydroartemisinin, among which 16 g had the superior potency with IC50 values ranging from 5.07 µM to 7.88 µM against four tested cancer cell lines. The cell cycle arrest revealed that 16 g induced A549 cell cycle arrest at G0/G1 phase via regulation of G1-related protein expression (Cdk4). Further mechanism studies reveal that 16 g induced A549 cells apoptosis via inhibiting Akt/Bad pathway. Moreover, 16 g depolarized the mitochondria membrane potentials and induced ROS generation in A549. Additionally, 16 g blocked migration of A549 cells in a concentration-dependent manner. What's more, 16 g is barely nontoxic to zebrafish embryos. Overall, the cell cycle arrest, inhibition of Akt/Bad signal pathway, ROS generation and migration blocked might explain the potent anti-proliferative activities of these compounds.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Artemisininas/farmacologia , Cinamatos/farmacologia , Descoberta de Drogas , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteína de Morte Celular Associada a bcl/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Artemisininas/química , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cinamatos/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Proteína de Morte Celular Associada a bcl/metabolismo
11.
Bioorg Chem ; 115: 105249, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34390971

RESUMO

A large number of derivatives of natural pentacyclic triterpenoid oleanolic acid (OA) with various activities have been reported, including CDDO derivatives (CDDOs). CDDOs show potent antitumor activity, but they lack selectivity for tumor cells which causes serious side effects. In this study, based on the truth that tumor cells display higher mitochondrial membrane potential, to improve their mitochondrial-targeting ability, triphenylphosphine cations (TPP+) or tricyclohexylphosphine cations (TCP+) were linked to CDDO. Among these compounds, the TPP+ derivative 5b exhibited greater activity against the tumor cells than CDDO-Me, and the selectivity for the tumor cells was obviously improved. Further investigation revealed that the uptake of 5b in the mitochondria of MCF-7 cells was increased compared to CDDO-Me. In addition, 5b was able to cause mitochondrial membrane potential decline and cell cycle arrest. Furthermore, 5b caused apoptosis mainly through the mitochondria-mediated intrinsic pathway. Taken together, our study provides a possible solution to the poor selectivity of CDDOs, and regains confidence in the treatment of tumor with CDDOs.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Mitocôndrias/efeitos dos fármacos , Ácido Oleanólico/análogos & derivados , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Mitocôndrias/metabolismo , Estrutura Molecular , Ácido Oleanólico/síntese química , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Relação Estrutura-Atividade
12.
Genes Dev ; 27(16): 1821-33, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23964096

RESUMO

Programmed mutagenesis of the immunoglobulin locus of B lymphocytes during class switch recombination (CSR) and somatic hypermutation requires RNA polymerase II (polII) transcription complex-dependent targeting of the DNA mutator activation-induced cytidine deaminase (AID). AID deaminates cytidine residues on substrate sequences in the immunoglobulin (Ig) locus via a transcription-dependent mechanism, and this activity is stimulated by the RNA polII stalling cofactor Spt5 and the 11-subunit cellular noncoding RNA 3'-5' exonucleolytic processing complex RNA exosome. The mechanism by which the RNA exosome recognizes immunoglobulin locus RNA substrates to stimulate AID DNA deamination activity on its in vivo substrate sequences is an important question. Here we report that E3-ubiquitin ligase Nedd4 destabilizes AID-associated RNA polII by a ubiquitination event, leading to generation of 3' end free RNA exosome RNA substrates at the Ig locus and other AID target sequences genome-wide. We found that lack of Nedd4 activity in B cells leads to accumulation of RNA exosome substrates at AID target genes and defective CSR. Taken together, our study links noncoding RNA processing following RNA polII pausing with regulation of the mutator AID protein. Our study also identifies Nedd4 as a regulator of noncoding RNAs that are generated by stalled RNA polII genome-wide.


Assuntos
Linfócitos B/enzimologia , Citidina Desaminase/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , RNA Polimerase II/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular Tumoral , Células Cultivadas , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Região de Troca de Imunoglobulinas/genética , Camundongos , Ubiquitina-Proteína Ligases Nedd4 , Proteínas Nucleares/metabolismo , Ligação Proteica , Fatores de Elongação da Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
13.
Bioorg Chem ; 104: 104208, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32919131

RESUMO

Based on the structure of signal transducer and activator of transcription 3 (STAT3), a series of 1,4-naphthoquinones derived from plumbagin (PL) with STAT3 inhibition potential were designed, synthesized, and biologically evaluated in vitro against several human cancer cell lines (MDA-MB-231, HepG2 and A549 cells) and three normal cells. The structure-activity relationship (SAR) and molecular docking result showed that the presence of hydroxyl group at C-5 of PL might interact with STAT3 in the form of hydrogen bonds, which is conducive to the binding of this kind structures with STAT3. Among the target compounds, 7a displayed the most potent inhibition against cancer cells and weaker cytotoxicity on normal cells than PL. The western bolting analysis showed that 7a could suppress the phosphorylation of STAT3 as well as the downstream genes instead of affecting its upstream tyrosine kinases (Src and JAK2) levels and p-STAT1 expression. Furthermore, molecular docking indicated that 7a bound to STAT3 more tightly than PL, and it could significantly induce the apoptosis of cancer cells in vitro. All these results may provide reference for the discovery of effective STAT3 inhibitors.


Assuntos
Antineoplásicos/farmacologia , Desenho de Fármacos , Naftoquinonas/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Naftoquinonas/síntese química , Naftoquinonas/química , Fator de Transcrição STAT3/metabolismo , Relação Estrutura-Atividade
14.
BMC Genomics ; 20(1): 519, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31234790

RESUMO

BACKGROUND: Banana wilt disease, caused by Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), is one of the most devastating diseases in banana (Musa spp.). Foc is a soil borne pathogen that causes rot of the roots or wilt of leaves by colonizing the xylem vessels. The dual RNA sequencing is used to simultaneously assess the transcriptomes of pathogen and host. This method greatly helps to understand the responses of pathogen and host to each other and discover the potential pathogenic mechanism. RESULTS: Plantlets of two economically important banana cultivars, Foc TR4 less susceptible cultivar NK and susceptible cultivar BX, were used to research the Foc-banana interaction mechanism. Notably, the infected NK had more significantly up-regulated genes on the respiration machinery including TCA cycle, glyoxylate, glycerol, and glycolysis compared to BX at 27 h post inoculation (hpi). In addition, genes involved in plant-pathogen interaction, starch, sucrose, linolenic acid and sphingolipid metabolisms were uniquely more greatly induced in BX than those in NK during the whole infection. Genes related to the biosynthesis and metabolism of SA and JA were greatly induced in the infected NK; while auxin and abscisic acid metabolisms related genes were strongly stimulated in the infected BX at 27 hpi. Furthermore, most of fungal genes were more highly expressed in the roots of BX than in those of NK. The fungal genes related to pathogenicity, pectin and chitin metabolism, reactive oxygen scavenging played the important roles during the infection of Foc. CCP1 (cytochrome c peroxidase 1) was verified to involve in cellulose utilization, oxidative stress response and pathogenicity of fungus. CONCLUSION: The transcriptome indicated that NK had much faster defense response against Foc TR4 than BX and the expression levels of fungal genes were higher in BX than those in NK. The metabolisms of carbon, nitrogen, and signal transduction molecular were differentially involved in pathogen infection in BX and NK. Additionally, the putative virulence associated fungal genes involved in colonization, nutrition acquirement and transport provided more insights into the infection process of Foc TR4 in banana roots.


Assuntos
Fusarium/genética , Musa/genética , Doenças das Plantas/microbiologia , Citocromo-c Peroxidase/metabolismo , Metabolismo Energético , Fusarium/patogenicidade , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Musa/microbiologia , Doenças das Plantas/genética , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/genética , Transdução de Sinais , Transcriptoma
15.
Bioorg Med Chem Lett ; 29(9): 1138-1142, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30837097

RESUMO

A series of artemisinin derivatives with MDR reversal activity were designed and synthesized. All hybrids were screened to anticancer activities against four human cancer cell lines (A549, MCF-7, HepG-2, MDA-MB-231) and normal human hepatic cell (L02) in vitro. Most of the new compounds showed higher anticancer activities than artemisinin, among which compounds 11a and 11c displayed superior potency with IC50 6.78 µM and 5.25 µM against MCF-7, respectively. The further research indicated that the most potent 11c induced cell cycle arrest at G2 phase in MCF-7. Additionally, compound 11c showed remarkable MDR reversal activity which reversed adriamycin against MCF-7/ADR cells with IC50 0.76 µM.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Artemisininas/síntese química , Artemisininas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos , Antineoplásicos/química , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos , Humanos , Células MCF-7 , Relação Estrutura-Atividade
16.
Langmuir ; 34(21): 6183-6193, 2018 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-29733597

RESUMO

Protein-mediated endocytosis of membrane is a key event in biological system. The mechanism, however, is still not clear. Using a de novo designed bola-type peptide KKKLLLLLLLLKKK (K3L8K3) as a protein mimic, we studied how it induced giant unilamellar vesicle (GUV) to form inward buds or endocytosis at varying conditions. Results show that the inward budding is initiated as the charged lipids are neutralized by K3L8K3, which results in a negative spontaneous curvature. If the charged lipids have unsaturated tails, the buddings are slim fibrils, which can further wrap into a spherical structure. In the case of saturated charged lipids, the buddings are rigid tubules, stable in the studied time period. The unsaturated lipid to saturated lipid ratio in the mother membrane is another key parameter governing the shape and dynamics of the buds. A complete endocytosis is observed when K3L8K3 is attached with a hydrophobic moiety, suggesting that hydrophobic interaction helps the buds to detach from the mother membrane. The molecules in the surrounding medium, such as negatively charged oligonucleotides, are engulfed into the GUV via endocytosis pathway induced by K3L8K3. Our study provides a novel strategy for illustrating the endocytosis mechanism by using peptides of simple sequence.


Assuntos
Endocitose/fisiologia , Membranas/metabolismo , Peptídeos/química , Interações Hidrofóbicas e Hidrofílicas , Lipídeos/química , Mimetismo Molecular
17.
Bioorg Med Chem Lett ; 27(2): 147-151, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27956344

RESUMO

12 novel scopoletin-isoxazole and scopoletin-pyrazole hybrids were designed, synthesized and their chemical structures were confirmed by HR-MS, IR, 1H NMR and 13C NMR spectra. The anticancer activities of the newly synthesized compounds were evaluated in vitro against three human cancer cell lines including HCT-116, Hun7 and SW620 by MTT assay. The screening results showed that six compounds (9a, 9c, 9d, 12a, 18b and 18d) exhibited potent cytotoxic activities with IC50 values below 20µM. Besides, we have further evaluated the growth inhibitory activities of six compounds against the human normal tissue cell lines HFL-1. Especially, compound 9d displayed significant anti-proliferative activity with IC50 values ranging from 8.76µM to 9.83µM and weak cytotoxicity with IC50 value of 90.9µM on normal cells HFL-1, which suggested that isoxazole-based hybrids of scopoletin were an effective chemical modification to improve the anticancer activity of scopoletin.


Assuntos
Antineoplásicos/farmacologia , Isoxazóis/farmacologia , Pirazóis/farmacologia , Escopoletina/análogos & derivados , Escopoletina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Humanos , Indóis/farmacologia , Isoxazóis/síntese química , Isoxazóis/toxicidade , Pirazóis/síntese química , Pirazóis/toxicidade , Pirróis/farmacologia , Escopoletina/síntese química , Escopoletina/toxicidade , Sunitinibe
18.
Nanotechnology ; 28(12): 125703, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28163262

RESUMO

Poly(methyl methacrylate) (PMMA) residue has long been a critical challenge for practical applications of the transferred chemical vapor deposited (CVD) graphene. Thermal annealing is empirically used for the removal of the PMMA residue; however experiments imply that there are still small amounts of residues left after thermal annealing which are hard to remove with conventional methods. In this paper, the thermal degradation of the PMMA residue upon annealing was studied by Raman spectroscopy. The study reveals that post-annealing residues are generated by the elimination of methoxycarbonyl side chains in PMMA and are believed to be absorbed on graphene via the π-π interaction between the conjugated unsaturated carbon segments and graphene. The post-annealing residues are difficult to remove by further annealing in a non-oxidative atmosphere due to their thermal and chemical stability. An electrolytic cleaning method was shown to be effective in removing these post-annealing residues while preserving the underlying graphene lattice based on Raman spectroscopy and atomic force microscopy studies. Additionally, a solution-gated field effect transistor was used to study the transport properties of the transferred CVD graphene before thermal annealing, after thermal annealing, and after electrolytic cleaning, respectively. The results show that the carrier mobility was significantly improved, and that the p-doping was reduced by removing PMMA residues and post-annealing residues. These studies provide a more in-depth understanding on the thermal annealing process for the removal of the PMMA residues from transferred CVD graphene and a new approach to remove the post-annealing residues, resulting in a residue-free graphene.

19.
Cell Biochem Funct ; 35(7): 472-476, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29052243

RESUMO

Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis with massive neuronal loss and severe gliosis. Aberrant neurogenesis has been shown in the epileptogenesis process of temporal lobe epilepsy. However, the molecular mechanisms underlying aberrant neurogenesis remain unclear. The roles of Wnt signalling cascade have been well established in neurogenesis during multiple aspects. Here, we used kainic acid-induced rat epilepsy model to investigate whether Wnt/ß-catenin signalling pathway is involved in the aberrant neurogenesis in temporal lobe epilepsy. Immunostaining and western blotting results showed that the expression levels of ß-catenin, Wnt3a, and cyclin D1, the key regulators in Wnt signalling pathway, were up-regulated during acute epilepsy induced by the injection of kainic acids, indicating that Wnt signalling pathway was activated in kainic acid-induced temporal lobe epilepsy. Moreover, BrdU labelling results showed that blockade of the Wnt signalling by knocking down ß-catenin attenuated aberrant neurogenesis induced by kainic acids injection. Altogether, Wnt/ß-catenin signalling pathway mediated hippocampal neurogenesis during epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy. Temporal lobe epilepsy is a chronic disorder of nerve system, mainly characterized by hippocampal sclerosis. Aberrant neurogenesis has been shown to involve in the epileptogenesis process of temporal lobe epilepsy. In the present study, we discovered that Wnt3a/ß-catenin signalling pathway serves as a link between aberrant neurogenesis and underlying remodelling in the hippocampus, leading to temporal lobe epilepsy, which might provide new strategies for clinical treatment of temporal lobe epilepsy.


Assuntos
Epilepsia do Lobo Temporal/patologia , Hipocampo/metabolismo , Proteína Wnt3A/metabolismo , beta Catenina/metabolismo , Animais , Ciclina D1/metabolismo , Modelos Animais de Doenças , Epilepsia do Lobo Temporal/induzido quimicamente , Epilepsia do Lobo Temporal/metabolismo , Hipocampo/patologia , Ácido Caínico/toxicidade , Masculino , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Wistar , Regulação para Cima , Via de Sinalização Wnt , beta Catenina/antagonistas & inibidores , beta Catenina/genética
20.
Chem Biodivers ; 14(2)2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27447119

RESUMO

A new 19-oxo-18,19-seco-ursane-type triterpeonoid saponin, laevigin E (8), together with 17 known compounds (1 - 7 and 9 - 18) were isolated from the root bark of Ilex rotunda Thunb. Their structures were determined by various spectroscopic analysis. Among them, compounds 6, 9, 11, and 18 were isolated from this species for the first time, while compounds 10 and 12 were firstly isolated from the family Aquifoliaceae. Biological activity assay showed that all triterpenoids exhibit moderate cytotoxic activities against MCF7, A549, HeLa and LN229 cell lines. The four triterpenoid saponins (3, 4, 6, and 8) exhibit slightly better activities compared to the four triterpenoid sapogenins (1, 2, 5, and 7). Compound 8 showed the best cytotoxicity against A549, HeLa and LN229 cell lines with IC50 of 17.83, 22.58 and 30.98 µm, respectively.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Ilex/química , Casca de Planta/química , Raízes de Plantas/química , Saponinas/farmacologia , Triterpenos/farmacologia , Células HeLa , Humanos , Estrutura Molecular
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