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1.
Glob Chang Biol ; 30(1): e17005, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37905717

RESUMO

Climate change has induced substantial shifts in vegetation boundaries such as alpine treelines and shrublines, with widespread ecological and climatic influences. However, spatial and temporal changes in the upper elevational limit of alpine grasslands ("alpine grasslines") are still poorly understood due to lack of field observations and remote sensing estimates. In this study, taking the Tibetan Plateau as an example, we propose a novel method for automatically identifying alpine grasslines from multi-source remote sensing data and determining their positions at 30-m spatial resolution. We first identified 2895 mountains potentially having alpine grasslines. On each mountain, we identified a narrow area around the upper elevational limit of alpine grasslands where the alpine grassline was potentially located. Then, we used linear discriminant analysis to adaptively generate from Landsat reflectance features a synthetic feature that maximized the difference between vegetated and unvegetated pixels in each of these areas. After that, we designed a graph-cut algorithm to integrate the advantages of the Otsu and Canny approaches, which was used to determine the precise position of the alpine grassline from the synthetic feature image. Validation against alpine grasslines visually interpreted from a large number of high-spatial-resolution images showed a high level of accuracy (R2 , .99 and .98; mean absolute error, 22.6 and 36.2 m, vs. drone and PlanetScope images, respectively). Across the Tibetan Plateau, the alpine grassline elevation ranged from 4038 to 5380 m (5th-95th percentile), lower in the northeast and southeast and higher in the southwest. This study provides a method for remotely sensing alpine grasslines for the first-time at large scale and lays a foundation for investigating their responses to climate change.


Assuntos
Mudança Climática , Tecnologia de Sensoriamento Remoto , Tibet , Pradaria , Ecossistema
2.
Bioorg Chem ; 150: 107612, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38986418

RESUMO

The high level of tyrosinase leads to the generation of neuromelanin, further causing the abnormality of redox-related protein level and mediating the occurrence and development of Parkinson's disease (PD). However, the existing tyrosinase inhibitors are mostly natural product extracts or polyphenolic derivatives, which hindered them from penetrating the blood-brain barrier (BBB). Herein, we obtained a novel tyrosinase inhibitor, 2-06 (tyrosinase: monophenolase IC50 = 70.44 ± 22.69 µM, diphenolase IC50 = 1.89 ± 0.64 µM), through the structure-based screening method. The compound 2-06 presented good in vitro and in vivo safety, and can inhibit the tyrosinase and melanogenesis in B16F10. Moreover, this compound showed neuroprotective effects and Parkinsonism behavior improving function. 2-06 was proved to penetrate the BBB and enter the central nervous system (CNS). The exploration of the binding mode between 2-06 and tyrosinase provided the foundation for the subsequent structural optimization. This is the first research to develop a central-targeting tyrosinase inhibitor, which is crucial for in-depth study on the new strategy for utilizing tyrosinase inhibitors to treat PD.


Assuntos
Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos , Monofenol Mono-Oxigenase , Doença de Parkinson , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Animais , Relação Estrutura-Atividade , Camundongos , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Estrutura Molecular , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/síntese química , Humanos , Masculino , Simulação de Acoplamento Molecular , Barreira Hematoencefálica/metabolismo
3.
J Nanobiotechnology ; 22(1): 400, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38972995

RESUMO

Considerable attention has been directed towards exploring the potential efficacy of miR-155 in the realm of cancer immunotherapy. Elevated levels of miR-155 in dendritic cells (DCs) have been shown to enhance their maturation, migration, cytokine secretion, and their ability to promote T cell activation. In addition, overexpression of mir155 in M2 macrophages boost the polarization towards the M1 phenotype. Conversely, miR-155 has the propensity to induce the accumulation of immunosuppressive cells like regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) in the tumor tissue. To account for this discrepancy, it is imperative to get help from a drug that could deal with immunosuppressive effect. Curcumin (CUR) exhibits the capacity to prompt Tregs converse into T helper 1 cells, fostering the polarization of M2 tumor-associated macrophage towards the M1 phenotype, and impeding the recruitment and aggregation of MDSCs within the tumor microenvironment. Nonetheless, CUR is known to exert an immunosuppressive impact on DCs by hindering the expression of maturation markers, cytokines, and chemokines, thereby prevent DCs response to immunostimulatory agents. Hence, a reactive oxygen species/glutathione dual responsive drug conveyance platform (CUR/miR155@DssD-Hb NPs) was devised to co-deliver CUR and miR155, with the aim of exploring their synergistic potential in bolstering a sustained and robust anti-tumor immune response. In vitro and in vivo results have suggested that CUR/miR155@DssD-Hb NPs can effectively inhibit the viability of 4T1 and B16F10 tumor cells, trigger the release of damage associated molecular patterns, stimulate DCs maturation, subsequent activation of CD8+ T cells, diminish immunosuppressive cell populations (MDSCs, Tregs, M2 TAMs and exhausted T cells), promote the formation of long-term immunity and lessen the formation of metastatic nodules in the lungs. In summary, the co-delivery system integrating CUR and miR155 (CUR/miR155@DssD-Hb NPs) demonstrates promise as a promising strategy for the immunotherapy of melanoma and triple negative breast cancer.


Assuntos
Curcumina , Células Dendríticas , Imunoterapia , MicroRNAs , Nanopartículas , Espécies Reativas de Oxigênio , Curcumina/farmacologia , Curcumina/química , MicroRNAs/genética , Animais , Camundongos , Nanopartículas/química , Espécies Reativas de Oxigênio/metabolismo , Imunoterapia/métodos , Células Dendríticas/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Camundongos Endogâmicos C57BL , Microambiente Tumoral/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Humanos , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Neoplasias/imunologia
4.
J Biochem Mol Toxicol ; 37(10): e23436, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37376914

RESUMO

Matrine, an effective component extracted from the traditional Chinese herb, Sophora flavescens, has been indicated to exert antitumor activity in different types of cancer. However, the role and precise mechanism of matrine in the progression of liver cancer remains largely unclear. Cell viability, cell proliferation, cell apoptosis, and Warburg effect were estimated by cell counting kit-8 assay, colony formation assay, flow cytometry assay, and glucose uptake and lactate production assay, respectively. The candidate Circular RNAs (circRNAs) were screened by integrating the Gene Expression Omnibus database (GSE155949) analysis with the online program GEO2R. A quantitative real-time polymerase chain reaction was employed to test the expression of circRNA circROBO1, microRNA miR-130a-5p, and roundabout homolog 1 (ROBO1). The interaction of circROBO1/miR-130a-5p/ROBO1 axis was predicted and confirmed by bioinformatics analysis, a dual-luciferase reporter assay, and an RNA pull-down assay. A xenograft mouse model was employed to reveal the role of matrine in vivo. Matrine repressed liver cancer cell viability, proliferation, and Warburg effect, but increased cell apoptosis in vitro. CircROBO1 and ROBO1 were upregulated, but miR-130a-5p was downregulated in liver cancer tissues. Additionally, matrine could reduce the expression of circROBO1 and ROBO1, and increase the expression of miR-130a-5p. Mechanically, overexpression of circROBO1 partly recovered the effect of matrine on liver cancer cell viability, proliferation, apoptosis, and Warburg effect by regulating the miR-130a-5p/ROBO1 axis. Matrine impeded liver cancer development by mediating the circROBO1/miR-130a-5p/ROBO1 axis, which provided a theoretical basis for the application of matrine as an effective anticancer drug for liver cancer.

5.
Mar Drugs ; 21(3)2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36976201

RESUMO

Cancer-derived small extracellular vesicles (sEVs) serve as critical mediators of cell-to-cell communication. Manzamine A (MA), a unique marine-derived alkaloid with various bioactivities, exerts anticancer effects against several kinds of tumors, but it remains unclear whether it has the same activity against breast cancer. Here, we proved that MA inhibits MDA-MB-231 and MCF-7 cell proliferation, migration, and invasion in a time- and dose-dependent manner. In addition, MA promotes autophagosome formation but suppresses autophagosome degradation in breast cancer cells. Importantly, we also found that MA stimulates sEVs secretion and increases autophagy-related protein accumulation in secreted sEVs, further potentiated by autophagy inhibitor chloroquine (CQ). Mechanistically, MA decreases the expression level of RIP1, the key upstream regulator of the autophagic pathway, and reduces the acidity of lysosome. Overexpression of RIP1 activated AKT/mTOR signaling, thus attenuating MA-induced autophagy and the corresponding secretion of autophagy-associated sEVs. Collectively, these data suggested that MA is a potential inhibitor of autophagy by preventing autophagosome turnover, and RIP1 mediates MA-induced secretory autophagy, which may be efficacious for breast cancer treatment.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/patologia , Autofagia , Transdução de Sinais , Linhagem Celular Tumoral , Proliferação de Células , Apoptose
6.
Cell Mol Biol (Noisy-le-grand) ; 68(8): 110-115, 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36800825

RESUMO

To explore the value of the Helicobacter pylori test in combination with the determination of plasma pepsinogen (PG) and gastrin 17 in screening the precancerous status of gastric cancer and gastric cancer in the healthy population, between 2019 and 2022, we enrolled a total of 402 subjects who went to the physical examination in the Center of Health Management of Ganzhou people's Hospital and additionally underwent the urea (14C) breath test and determination of PGI, PGII and G-17. Anomalies in Hp, PG or G-17 ≥ 2, or a single anomaly in PG determination would be taken as positive, and the diagnosis should be further confirmed by the gastroscopy and pathological test. According to the results, subjects would be further divided into the gastric cancer group, precancerous lesion group, precancerous disease group and control group, aiming to clarify the relationship between Hp, PG and G-17 levels and the precancerous status and development of gastric cancer and the screening value. Results showed that Hp-positive infection was found in 341 subjects (84.82%). Hp infection rate in the control group was much lower than those in the precancerous disease group, precancerous lesion group and gastric cancer group (P < 0.05). The CagA positive rates in the gastric cancer group and precancerous lesion group were significantly higher than those in the precancerous disease group and control group, while the serum level of G-17 in the gastric cancer group was much higher than those in the precancerous lesion group, precancerous disease group and control group (P < 0.05), and the PG I/II ratio in the gastric cancer patients was also lower than those in the precancerous lesion group, precancerous disease group and control group (P < 0.05). As the disease progressed, the G-17 level also increased but PG I/II ratio decreased gradually (P < 0.001). Hp test in combination with PG and G-17 shows a high value in determining the precancerous status of gastric cancer and screening for gastric cancer in healthy subjects.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Lesões Pré-Cancerosas , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico , Detecção Precoce de Câncer , Pepsinogênio A , Pepsinogênio C , Infecções por Helicobacter/diagnóstico , Lesões Pré-Cancerosas/diagnóstico
7.
Cell Mol Biol (Noisy-le-grand) ; 68(9): 160-164, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36905257

RESUMO

This research aimed to explore the clinical value of thin prep cytologic test (TCT) combined with human papillomavirus (HPV) and carbohydrate antigen 125 (CA125) in early cervical cancer screening in the physical examination population. For this purpose, a total of 3587 females who received gynecological physical examination in the outpatient department of Ganzhou people's Hospital from January 2018 to March 2022 were included and underwent TCT, HPV and carbohydrate antigen 125 upon admission. Colposcopy biopsy was performed on patients who tested positive for any of the three indicators. Then using pathological diagnosis as the gold standard, the three methods applied alone or in combination were evaluated in terms of sensitivity, specificity, diagnostic yield and Youden index. Results showed that Among the 3587 females, 476 (13.27%) were HPV positive, 364 (10.14%) CA125 positive, and 314 (8.75%) TCT positive. Furthermore, 738 tested positive for any of the three indicators and underwent cervical biopsy. Among the 738 cases, 280 (39.94%) developed chronic cervicitis, 268 (36.31%) low-level cervical intraepithelial neoplasia (CIN), 173 (23.44%) high-level CIN, and 17 (2.30%) cervical cancer. HPV+TCT+CA125 combined screening showed higher sensitivity (94.54%), specificity (83.92%), diagnostic coincidence rate (87.46%) and Youden index (0.760) than single-indicator examinations. Also, it had the largest area under the receiver operating characteristic (ROC) curve, 0.673 (0.647, 0.699), compared to any other screening method. In conclusion, The combined detection of CA125, HPV and TCT is of clinical significance due to its higher sensitivity and accuracy in early screening of cervical cancer in the physical examination population.


Assuntos
Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Detecção Precoce de Câncer/métodos , Papillomavirus Humano , Papillomaviridae , Sensibilidade e Especificidade , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/patologia
8.
Mol Pharm ; 17(4): 1114-1126, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32176509

RESUMO

The efflux of anticancer agents mediated by P-glycoprotein (P-gp) is one of the main causes of multidrug resistance (MDR) and eventually leads to chemotherapy failure. To overcome this problem, the delivery of anticancer agents in combination with a P-gp inhibitor using nanocarrier systems is considered an effective strategy. On the basis of the physiological compatibility and excellent drug loading ability of erythrocytes, we hypothesized that nanoerythrocytes could be used for the codelivery of an anticancer agent and a P-gp inhibitor to overcome MDR in breast cancer. Herein, a folic acid-modified nanoerythrocyte system (PTX/TQR NPs@NanoRBC-PEG/FA) was prepared to simultaneously transport paclitaxel and tariquidar, and the in vitro and in vivo characteristics of this delivery system were evaluated through several experiments. The results indicated that the average diameter and surface potential of this nanocarrier system were 159.8 ± 1.4 nm and -10.98 mV, respectively. Within 120 h, sustained release of paclitaxel was observed in both pH 6.5 media and pH 7.4 media. Tariquidar release from this nanocarrier suppressed the P-gp function of MCF-7/Taxol cells and significantly increased the intracellular paclitaxel level (p < 0.01 versus the PTX group). The results of the MTT assay indicated that the simultaneous transportation of paclitaxel and tariquidar could significantly inhibit the growth of MCF-7 cells or MCF-7/Taxol cells. After 48 h of incubation with PTX/TQR NPs@NanoRBC-PEG/FA, the viability of MCF-7 cells and MCF-7/Taxol cells decreased to 7.37% and 30.2%, respectively, and the IC50 values were 2.49 µM and 6.30 µM. Pharmacokinetic results illustrated that, compared with free paclitaxel, all test paclitaxel nanoformulations prolonged the drug release time and showed similar plasma concentration-time profiles. The peak concentration (Cmax), area under the curve (AUC0-∞), and half-life (t1/2) of PTX/TQR NPs@NanoRBC-PEG/FA were 3.33 mg/L, 6.02 mg/L·h, and 5.84 h, respectively. Moreover, this active targeting nanocarrier dramatically increased the paclitaxel level in tumor tissues. Furthermore, compared with those of the other paclitaxel formulations, the cellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels of the PTX/TQR NPs@NanoRBC-PEG/FA group increased by 1.38-fold (p < 0.01) and 1.36-fold (p < 0.01), respectively, and the activities of superoxide dismutase (SOD) and catalase (CAT) decreased to 67.8% (p < 0.01) and 65.4% (p < 0.001), respectively. More importantly, in vivo antitumor efficacy results proved that the PTX/TQR NPs@NanoRBC-PEG/FA group exerted an outstanding tumor inhibition effect with no marked body weight loss and fewer adverse effects. In conclusion, by utilizing the inherent and advantageous properties of erythrocytes and surface modification strategies, this biomimetic targeted drug delivery system provides a promising platform for the codelivery of an anticancer agent and a P-gp inhibitor to treat MDR in breast cancer.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Ácido Fólico/farmacologia , Paclitaxel/farmacologia , Quinolinas/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Neoplasias da Mama/metabolismo , Catalase/metabolismo , Linhagem Celular Tumoral , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Eritrócitos/metabolismo , Feminino , Humanos , Células MCF-7 , Masculino , Malondialdeído/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nanopartículas/química , Tamanho da Partícula , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
9.
Mar Drugs ; 18(6)2020 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-32545859

RESUMO

As prebiotics, galacto-oligosaccharides (GOSs) can improve the intestinal flora and have important applications in medicine. ß-galactosidases could promote the synthesis of GOSs in lactose and catalyze the hydrolysis of lactose. In this study, a new ß-galactosidase gene (gal2A), which belongs to the glycoside hydrolase family 2, was cloned from marine bacterium Alteromonas sp. QD01 and expressed in Escherichia coli. The molecular weight of Gal2A was 117.07 kDa. The optimal pH and temperature of Gal2A were 8.0 and 40 °C, respectively. At the same time, Gal2A showed wide pH stability in the pH range of 6.0-9.5, which is suitable for lactose hydrolysis in milk. Most metal ions promoted the activity of Gal2A, especially Mn2+ and Mg2+. Importantly, Gal2A exhibited high transglycosylation activity, which can catalyze the formation of GOS from milk and lactose. These characteristics indicated that Gal2A may be ideal for producing GOSs and lactose-reducing dairy products.


Assuntos
Alteromonas/química , Lactose/química , Leite , Prebióticos , beta-Galactosidase/química , Alteromonas/genética , Animais , Clonagem Molecular , Indústria de Laticínios , Oligossacarídeos/química , beta-Galactosidase/genética
10.
Chem Biodivers ; 17(4): e2000057, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32091654

RESUMO

Two julichrome monomers, julichromes Q11 (1) and Q12 (2), along with five known julichromes (Q10 , Q3 ⋅ 5 , Q3 ⋅ 3 , Q6 ⋅ 6 , Q6 , 3-7) and four known anthraquinones (chrysophanol, 4-acetylchrysophanol, islandicin, huanglongmycin A, 8-11), were isolated from the marine gastropod mollusk Batillaria zonalis-associated Streptomyces sampsonii SCSIO 054. This is the first report of julichromes isolated from a marine source. Extensive dissection of 1D and 2D NMR datasets combined with X-ray crystallography enabled rigorous elucidation of the previously reported configurations of julichrome Q3 ⋅ 5 (4) and related julichrome Q3 ⋅ 3 (5); both of the configuration at C(9) needs to be revised. In addition, julichrome Q12 (2) was found to display antibacterial activity against Micrococcus luteus and Bacillus subtilis with MICs of 2.0 and 8.0 µg mL-1 ; four compounds (1, 3, 6, 7) also showed inhibitory activities against an array of methicillin-resistant Staphylococcus aureus, S. aureus and S. simulans AKA1 with MIC values ranging from 8 to 64 µg mL-1 .


Assuntos
Antibacterianos/química , Gastrópodes/microbiologia , Naftalenos/química , Streptomyces/química , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Cristalografia por Raios X , Testes de Sensibilidade Microbiana , Micrococcus luteus/efeitos dos fármacos , Conformação Molecular , Naftalenos/isolamento & purificação , Naftalenos/farmacologia , Filogenia , Estereoisomerismo , Streptomyces/classificação , Streptomyces/metabolismo
11.
Int J Mol Sci ; 21(5)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32121010

RESUMO

The recent emergence of antibiotic-resistant bacteria requires the development of new antibiotics or new agents capable of enhancing antibiotic activity. Lysozyme degrades bacterial cell wall without involving antibiotic resistance and has become a new antibacterial strategy. However, direct use of native, active proteins in clinical settings is not practical as it is fragile under various conditions. In this study, lysozyme was integrated into chitosan nanoparticles (CS-NPs) by the ionic gelation technique to obtain lysozyme immobilized chitosan nanoparticles (Lys-CS-NPs) and then characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), which showed a small particle size (243.1 ± 2.1 nm) and positive zeta potential (22.8 ± 0.2 mV). The immobilization significantly enhanced the thermal stability and reusability of lysozyme. In addition, compared with free lysozyme, Lys-CS-NPs exhibited superb antibacterial properties according to the results of killing kinetics in vitro and measurement of the minimum inhibitory concentration (MIC) of CS-NPs and Lys-CS-NPs against Pseudomonas aeruginosa (P. aeruginosa), Klebsiella pneumoniae (K. pneumoniae), Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus). These results suggest that the integration of lysozyme into CS-NPs will create opportunities for the further potential applications of lysozyme as an anti-bacterium agent.


Assuntos
Antibacterianos/farmacologia , Quitosana/química , Portadores de Fármacos/química , Muramidase/farmacologia , Nanopartículas/química , Difusão Dinâmica da Luz , Estabilidade Enzimática , Enzimas Imobilizadas/farmacologia , Escherichia coli/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Temperatura
12.
Bioorg Med Chem Lett ; 29(18): 2638-2645, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31400938

RESUMO

Histone deacetylases (HDACs) have proven to be promising targets for the development of anti-cancer drugs. In this study, we reported a series of novel chalcone based tubulin and HDAC dual-targeting inhibitors. Three compounds inhibited the activities of HDAC and tubulin polymerization simultaneously and displayed anti-proliferative activities toward eleven human tumor cell lines. Compound 8a remarkably induced growth inhibition, apoptosis and G2/M phase arrest of A549 tumor cells. Finally, the inhibitory activities of 8a against HDAC6 and tubulin were rationalized by molecular docking studies.


Assuntos
Antineoplásicos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Tubulina (Proteína)/metabolismo , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade
13.
Acta Pharmacol Sin ; 40(5): 666-676, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30218072

RESUMO

Hispidulin (4',5,7-trihydroxy-6-methoxyflavone) is a phenolic flavonoid isolated from the medicinal plant S. involucrata, which exhibits anti-neoplastic activity against several types of cancer. However, the mechanism underlying its anti-cancer activity against hepatocellular carcinoma (HCC) has not been fully elucidated. In this study, we investigated whether and how hispidulin-induced apoptosis of human HCC cells in vitro and in vivo. We showed that hispidulin (10, 20 µmol/L) dose-dependently inhibited cell growth and promoted apoptosis through mitochondrial apoptosis pathway in human HCC SMMC7721 cells and Huh7 cells. More importantly, we revealed that its pro-apoptotic effects depended on endoplasmic reticulum stress (ERS) and unfolded protein response (UPR), as pretreatment with salubrinal, a selective ERS inhibitor, or shRNA targeting a UPR protein CHOP effectively abrogated hispidulin-induced cell apoptosis. Furthermore, we showed that hispidulin-induced apoptosis was mediated by activation of AMPK/mTOR signaling pathway as pretreatment with Compound C, an AMPK inhibitor, or AMPK-targeting siRNA reversed the pro-apoptotic effect of hispidulin. In HCC xenograft nude mice, administration of hispidulin (25, 50 mg/kg every day, ip, for 27 days) dose-dependently suppressed the tumor growth, accompanied by inducing ERS and apoptosis in tumor tissue. Taken together, our results demonstrate that hispidulin induces ERS-mediated apoptosis in HCC cells via activating the AMPK/mTOR pathway. This study provides new insights into the anti-tumor activity of hispidulin in HCC.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Flavonas/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Flavonas/farmacologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Mar Drugs ; 17(1)2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30669556

RESUMO

Chitooligosaccharides (CHOS) have gained increasing attention because of their important biological activities. Enhancing the efficiency of CHOS production essentially requires screening of novel chitosanase with unique characteristics. Therefore, a rapid and efficient one-step affinity purification procedure plays important roles in screening native chitosanases. In this study, we report the design and synthesis of affinity resin for efficient purification of native chitosanases without any tags, using chitodisaccharides (CHDS) as an affinity ligand, to couple with Sepharose 6B via a spacer, cyanuric chloride. Based on the CHDS-modified affinity resin, a one-step affinity purification method was developed and optimized, and then applied to purify three typical glycoside hydrolase (GH) families: 46, 75, and 80 chitosanase. The three purified chitosanases were homogeneous with purities of greater than 95% and bioactivity recovery of more than 40%. Moreover, we also developed a rapid and efficient affinity purification procedure, in which tag-free chitosanase could be directly purified from supernatant of bacterial culture. The purified chitosanases samples using such a procedure had apparent homogeneity, with more than 90% purity and 10⁻50% yield. The novel purification methods established in this work can be applied to purify native chitosanases in various scales, such as laboratory and industrial scales.


Assuntos
Quitina/análogos & derivados , Cromatografia de Afinidade/instrumentação , Glicosídeo Hidrolases/isolamento & purificação , Quitina/síntese química , Quitosana , Cromatografia de Afinidade/métodos , Ligantes , Oligossacarídeos , Sefarose/química , Triazinas/química
15.
Mar Drugs ; 17(5)2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31137685

RESUMO

Alginate oligosaccharides (AOS) show versatile bioactivities. Although various alginate lyases have been characterized, enzymes with special characteristics are still rare. In this study, a polysaccharide lyase family 7 (PL7) alginate lyase-encoding gene, aly08, was cloned from the marine bacterium Vibrio sp. SY01 and expressed in Escherichia coli. The purified alginate lyase Aly08, with a molecular weight of 35 kDa, showed a specific activity of 841 U/mg at its optimal pH (pH 8.35) and temperature (45 °C). Aly08 showed good pH-stability, as it remained more than 80% of its initial activity in a wide pH range (4.0-10.0). Aly08 was also a thermo-tolerant enzyme that recovered 70.8% of its initial activity following heat shock treatment for 5 min. This study also demonstrated that Aly08 is a polyG-preferred enzyme. Furthermore, Aly08 degraded alginates into disaccharides and trisaccharides in an endo-manner. Its thermo-tolerance and pH-stable properties make Aly08 a good candidate for further applications.


Assuntos
Organismos Aquáticos/enzimologia , Polissacarídeo-Liases/metabolismo , Temperatura , Vibrio/enzimologia , Organismos Aquáticos/genética , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Polissacarídeo-Liases/química , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/isolamento & purificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Vibrio/genética
16.
Molecules ; 24(1)2019 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-30621320

RESUMO

Chitosanases play an important role in chitosan degradation, forming enzymatic degradation products with several biological activities. Although many chitosanases have been discovered and studied, the enzymes with special characteristics are still rather rare. In this study, a new chitosanase, CsnM, with an apparent molecular weight of 28 kDa was purified from the marine bacterium Pseudoalteromonas sp. SY39. CsnM is a cold-adapted enzyme, which shows highest activity at 40 °C and exhibits 30.6% and 49.4% of its maximal activity at 10 and 15 °C, respectively. CsnM is also a thermo-tolerant enzyme that recovers 95.2%, 89.1% and 88.1% of its initial activity after boiling for 5, 10 and 20 min, respectively. Additionally, CsnM is an endo-type chitosanase that yields chitodisaccharide as the main product (69.9% of the total product). It's cold-adaptation, thermo-tolerance and high chitodisaccharide yield make CsnM a superior candidate for biotechnological application to produce chitooligosaccharides.


Assuntos
Proteínas de Bactérias/metabolismo , Glicosídeo Hidrolases/metabolismo , Pseudoalteromonas/enzimologia , Proteínas de Bactérias/isolamento & purificação , Quitina/análogos & derivados , Quitina/metabolismo , Quitosana , Glicosídeo Hidrolases/isolamento & purificação , Peso Molecular , Oligossacarídeos , Temperatura
17.
Cancer Sci ; 109(5): 1369-1381, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29575334

RESUMO

Colorectal cancer (CRC) accounts for over 600 000 deaths annually worldwide. The current study aims to evaluate the value of proto-oncogene PIM1 as a therapeutic target in CRC and investigate the anticancer activity of hispidulin, a naturally occurring phenolic flavonoid compound, against CRC. Immunohistochemistry analysis showed that PIM1 was upregulated in CRC tissue. The role of PIM1 as an oncogene was evidenced by the fact that PIM1 knockdown inhibits cell growth, induces apoptosis, and suppresses invasion. Our results showed that hispidulin exerts antitumor activity in CRC through inhibiting the expression of PIM1. Moreover, our findings revealed that hispidulin downregulated the expression of PIM1 by inhibiting JAK2/STAT3 signaling by generating reactive oxygen species. Furthermore, our in vivo studies showed that hispidulin can significantly inhibit tumor growth and metastasis in CRC. Collectively, our results provide an experimental basis for trialing hispidulin in CRC treatment. PIM1 can be considered a potential therapeutic target in CRC.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Flavonas/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Feminino , Flavonas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Janus Quinase 2/metabolismo , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Proto-Oncogene Mas , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição STAT3/metabolismo , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Glob Chang Biol ; 24(11): 5411-5425, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30156039

RESUMO

Climate warming on the Tibetan Plateau tends to induce an uphill shift of temperature isolines. Observations and process-based models have both shown that climate warming has resulted in an increase in vegetation greenness on the Tibetan Plateau in recent decades. However, it is unclear whether the uphill shift of temperature isolines has caused greenness isolines to shift upward and whether the two shifts match each other. Our analysis of satellite observed vegetation greenness during the growing season (May-Sep) and gridded climate data for 2000-2016 documented a substantial mismatch between the elevational shifts of greenness and temperature isolines. This mismatch is probably associated with a lagging response of greenness to temperature change and with the elevational gradient of greenness. The lagging response of greenness may be associated with water limitation, resources availability, and acclimation. This lag may weaken carbon sequestration by Tibetan ecosystems, given that greenness is closely related to primary carbon uptake and ecosystem respiration increases exponentially with temperature. We also found that differences in terrain slope angle accounted for large spatial variations in the elevational gradient of greenness and thus the velocity of elevational shifts of greenness isolines and the sensitivity of elevational shifts of greenness isolines to temperature, highlighting the role of terrain effects on the elevational shifts of greenness isolines. The mismatches and the terrain effect found in this study suggest that there is potentially large micro-topographical difference in response and acclimation/adaptation of greenness to temperature changes in plants. More widespread in situ measurements and fine-resolution remote sensing observations and fine-gridded climate data are required to attribute the mismatch to specific environmental drivers and ecological processes such as vertical changes in community structure, plant physiology, and distribution of species.


Assuntos
Mudança Climática , Ecossistema , Temperatura , Aclimatação , Sequestro de Carbono , Monitoramento Ambiental/métodos , Estações do Ano , Astronave , Tibet , Água
19.
Sensors (Basel) ; 18(9)2018 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-30231574

RESUMO

Deep learning techniques have boosted the performance of hyperspectral image (HSI) classification. In particular, convolutional neural networks (CNNs) have shown superior performance to that of the conventional machine learning algorithms. Recently, a novel type of neural networks called capsule networks (CapsNets) was presented to improve the most advanced CNNs. In this paper, we present a modified two-layer CapsNet with limited training samples for HSI classification, which is inspired by the comparability and simplicity of the shallower deep learning models. The presented CapsNet is trained using two real HSI datasets, i.e., the PaviaU (PU) and SalinasA datasets, representing complex and simple datasets, respectively, and which are used to investigate the robustness or representation of every model or classifier. In addition, a comparable paradigm of network architecture design has been proposed for the comparison of CNN and CapsNet. Experiments demonstrate that CapsNet shows better accuracy and convergence behavior for the complex data than the state-of-the-art CNN. For CapsNet using the PU dataset, the Kappa coefficient, overall accuracy, and average accuracy are 0.9456, 95.90%, and 96.27%, respectively, compared to the corresponding values yielded by CNN of 0.9345, 95.11%, and 95.63%. Moreover, we observed that CapsNet has much higher confidence for the predicted probabilities. Subsequently, this finding was analyzed and discussed with probability maps and uncertainty analysis. In terms of the existing literature, CapsNet provides promising results and explicit merits in comparison with CNN and two baseline classifiers, i.e., random forests (RFs) and support vector machines (SVMs).

20.
J Neurochem ; 142(2): 215-230, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28407242

RESUMO

Microglia over-activation contributes to neurodegenerative processes by neurotoxin factors and pro-inflammatory molecules of pro-inflammatory processes. Mitochondrial reactive oxygen species (ROS) and autophagy pathway might be involved in microglial activation, but the underlying mechanism is unclear. Here, we regulated autophagy pathway of microglia in vitro by autophagy inhibition (3-methyladenine treatment, siRNA-Beclin 1 or siRNA-ATG5 transfection) or induction (rapamycin treatment) in murine microglial BV-2 cells or cultured primary mouse microglial cells. And we found that autophagy inhibition could sensitize mitochondrial profile and microglial activation of cultured microglial cells, demonstrated by significant production of mitochondrial ROS, loss of mitochondrial membrane potential, secretion of pro-inflammatory cytokines including interleukin 1ß (IL-1ß), interleukin 6 (IL-6), interleukin 12 (IL-12) and tumor necrosis factor α and marked activation of mitogen-activated proteinkinases (MAPKs) and nuclear factor κB (NF-κB). These effects could be blocked by specific inhibitors of MAPK and NF-κB or mitochondrial antioxidants, Mito-TEMPO. Meanwhile, induction of autophagy with rapamycin treatment could significantly suppress microglial inflammatory responses, mitochondrial ROS production, activation of MAPKs and NF-κB. Taken together, our in vitro results from primary cultured microglia and BV-2 cell lines indicated that autophagy inhibition might participate in brain macrophage or microglia over-activation and mitochondrial ROS generation might be involved in the regulatory microglial pro-inflammatory responses.


Assuntos
Autofagia/fisiologia , Microglia/metabolismo , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Autofagia/efeitos dos fármacos , Células Cultivadas , Mediadores da Inflamação/metabolismo , Interleucina-12/metabolismo , Interleucina-6/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Microglia/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
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