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1.
Integr Zool ; 18(2): 333-352, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35841611

RESUMO

Unmanned aerial vehicle (UAV) technology, artificial intelligence, and the relevant hardware can be used for monitoring wild animals. However, existing methods have several limitations. Therefore, this study explored the monitoring and protection of Amur tigers and their main prey species using images from UAVs by optimizing the algorithm models with respect to accuracy, model size, recognition speed, and elimination of environmental interference. Thermal imaging data were collected from 2000 pictures with a thermal imaging lens on a DJI M300RTK UAV at the Hanma National Nature Reserve in the Greater Khingan Mountains in Inner Mongolia, Wangqing National Nature Reserve in Jilin Province, and Siberian Tiger Park in Heilongjiang Province. The YOLO V5s algorithm was applied to recognize the animals in the pictures. The accuracy rate was 94.1%, and the size of the model weight (total weight of each model layer trained with the training set) was 14.8 MB. The authors improved the structures and parameters of the YOLO V5s algorithm. As a result, the recognition accuracy rate became 96%, and the model weight was 9.3 MB. The accuracy rate increased by 1.9%, the model weight decreased by 37.2% from 14.8 MB to 9.3 MB, and the recognition time of a single picture was shortened by 34.4% from 0.032 to 0.021 s. This not only increases the recognition accuracy but also effectively lowers the hardware requirements that the algorithm relies on, which provides a lightweight fast recognition method for UAV-based edge computing and online investigation of wild animals.


Assuntos
Algoritmos , Inteligência Artificial , Animais , Animais Selvagens , China , Mamíferos
2.
Front Physiol ; 13: 1044308, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36324309

RESUMO

Detailed insight into the radiation-induced changes in tumor microvasculature is crucial to maximize the efficacy of radiotherapy against breast cancer. Recent advances in imaging have enabled precise targeting of solid lesions. However, intratumoral heterogeneity makes treatment planning and monitoring more challenging. Conventional imaging cannot provide high-resolution observation and longitudinal monitoring of large-scale microvascular in response to radiotherapy directly in deep tissues. Herein, we report on an emerging non-invasive imaging assessment method of morphological and functional tumor microvasculature responses with high spatio-temporal resolution by means of optoacoustic imaging (OAI). In vivo imaging of 4T1 breast tumor response to a conventional fractionated radiotherapy at varying dose (14 × 2 Gy and 3 × 8 Gy) has been performed after 2 weeks following treatment. Remarkably, optoacoustic images can generate richful contrast for the tumor microvascular architecture. Besides, the functional status of tumor microvasculature and tumor oxygenation levels were further estimated using OAI. The results revealed the differential (size-dependent) nature of vascular responses to radiation treatments at varying doses. The vessels exhibited an decrease in their density accompanied by a decline in the number of vascular segments following irradiation, compared to the control group. The measurements further revealed an increase of tumor oxygenation levels for 14 × 2 Gy and 3 × 8 Gy irradiations. Our results suggest that OAI could be used to assess the response to radiotherapy based on changes in the functional and morphological status of tumor microvasculature, which are closely linked to the intratumor microenvironment. OAI assessment of the tumor microenvironment such as oxygenation status has the potential to be applied to precise radiotherapy strategy.

3.
Cell ; 185(19): 3533-3550.e27, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-36113427

RESUMO

Integrins are validated drug targets with six approved therapeutics. However, small-molecule inhibitors to three integrins failed in late-stage clinical trials for chronic indications. Such unfavorable outcomes may in part be caused by partial agonism, i.e., the stabilization of the high-affinity, extended-open integrin conformation. Here, we show that the failed, small-molecule inhibitors of integrins αIIbß3 and α4ß1 stabilize the high-affinity conformation. Furthermore, we discovered a simple chemical feature present in multiple αIIbß3 antagonists that stabilizes integrins in their bent-closed conformation. Closing inhibitors contain a polar nitrogen atom that stabilizes, via hydrogen bonds, a water molecule that intervenes between a serine residue and the metal in the metal-ion-dependent adhesion site (MIDAS). Expulsion of this water is a requisite for transition to the open conformation. This change in metal coordination is general to integrins, suggesting broad applicability of the drug-design principle to the integrin family, as validated with a distantly related integrin, α4ß1.


Assuntos
Desenho de Fármacos , Integrina alfa4beta1 , Conformação Proteica , Serina , Água
4.
Exp Ther Med ; 22(5): 1234, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34539830

RESUMO

Geniposide is a bioactive iridoid glucoside derived from Gardenia jasminoides that has proven anti-inflammatory effects against acute lung injury. The aim of this study was to determine whether geniposide could protect pulmonary arterial smooth muscle cells (PASMCs) from lipopolysaccharide (LPS)-induced injury and to explore the participation of α7 nicotinic acetylcholine receptor (α7nAChR), which was previously reported to suppress pro-inflammatory cytokine production in LPS-stimulated macrophages. In the present study, rat PASMCs were isolated and stimulated using LPS. The effect of geniposide on LPS-induced PASMC injury was then explored. Geniposide exerted anti-apoptotic and anti-inflammatory effects on LPS-treated PASMCs, as demonstrated by the downregulation of pro-apoptotic proteins and pro-inflammatory cytokines, respectively. Furthermore, the α7nAChR agonist PNU282987 accentuated the protective effect of geniposide against LPS-induced injury in PASMCs by inhibiting toll-like receptor-4/myeloid differentiation primary response 88 (TLR-4/MyD88) signaling and downregulating nuclear factor (NF)-κB expression. Conversely, methyllycaconitine, an inhibitor of α7nAChR, attenuated the effects of geniposide. These findings collectively suggested that in conjunction with geniposide, the activation of α7nAChR may contribute to further mitigating LPS-induced PASMC apoptosis and inflammation. In addition, the underlying mechanisms critically involve the NF-κB/MyD88 signaling axis. These results may provide novel insights into the treatment and management of lung diseases via geniposide administration.

5.
Exp Ther Med ; 21(4): 354, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33732327

RESUMO

4-Hexylresorcinol (4HR) is a small organic compound that is widely used as an antiseptic and antioxidant. In the present study, its role in osteoclastogenesis was investigated. Bone marrow-derived macrophages from mice were used to examine the role of 4HR in osteogenesis. An ovariectomy (OVX) mouse model was constructed to examine the effect of 4HR in vivo, followed by hematoxylin and eosin and tartrate resistant acid phosphatase staining. In the present study, 4HR effectively suppressed receptor activator of NF-κB ligand-induced osteoclastogenesis in a dose-dependent manner. 4HR was also found to significantly suppress the expression of osteoclast (OC)-specific markers, including tartrate-resistant acid phosphatase, cathepsin K, nuclear factor of activated T-cell cytoplasmic 1 and c-Fos in the presence of RANKL in BMMs. Furthermore, 4HR inhibited osteoclastogenesis by inhibiting the activation of the NF-κB signaling pathway in BMMs. Consistent with the in vitro results, 4HR effectively ameliorated OVX-induced bone loss and markedly reduced OC number in the proximal tibia in vivo. In conclusion, the present results suggested that 4HR inhibited osteoclastogenesis in vitro and rescued bone loss in vivo, suggesting that 4HR may serve as a novel therapeutic agent for osteoporosis treatment.

6.
Zhongguo Zhen Jiu ; 41(2): 177-82, 2021 Feb 12.
Artigo em Chinês | MEDLINE | ID: mdl-33788466

RESUMO

OBJECTIVE: To observe the effect of acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) on the macrophage polarization of epididymis adipose tissue in obese mice, and to explore the action mechanism of acupoint thread-embedding on weight control. METHODS: Among 30 male C57BL/6 mice, 10 mice were randomly selected and fed with normal diet, and the remaining 20 mice were fed with high-fat diet to establish the obesity model. Sixteen mice with successful obesity model were randomly divided into a model group and an acupoint thread-embedding group, 8 mice in each group. Eight mice were selected from mice which were fed with normal diet as the normal group. On the next day of successful modeling, acupoint thread-embedding was performed at "Zusanli" (ST 36) and "Fenglong" (ST 40) in the acupoint thread-embedding group, once every 10 days for 4 times. The body weight was recorded at 0, 8, 16, 24, 32, 40 days into intervention; the level of glucose metabolism was compared after intervention; the level of lipid metabolism and weight of epididymal adipose tissue were compared at the end of the intervention; the mRNA expression of M1 and M2 macrophage-related cytokines interleukin-10 (IL-6), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were detected by real-time PCR; the mRNA and protein expression of M1 macrophage labeled inducible nitric oxide synthase (iNOS) and M2 macrophage labeled arginase-1 (Arg-1) were detected by real-time PCR and Western blot. RESULTS: Compared with the normal group, the body weight at 0, 8, 16, 24, 32, 40 days into intervention in the model group was increased (P<0.05); the results of glucose tolerance test at 0, 30, 60, 120 min and insulin tolerance test at 0, 30, 60, 90, 120 min in the model group were higher than those in the normal group (P<0.05); the levels of total cholesterol and triacylglycerol in the model group were significantly higher than those in the normal group (P<0.001, P<0.01); the weight of epididymal adipose tissue in the model group was significantly higher than that in the normal group (P<0.001); the mRNA expression of IL-6, MCP-1, TNF-α and iNOS was increased (P<0.05, P<0.01, P<0.001), that of IL-10, Arg-1 was decreased (P<0.01), the protein expression of iNOS was up-regulated (P<0.01), and that of Arg-1 was down-regulated (P<0.001). Compared with the model group, the body weight at 16, 24, 32, 40 days into treatment in the acupoint thread-embedding group was reduced (P<0.05); the results of glucose tolerance test at 30, 60, 120 min and insulin tolerance test at 30, 60 min in the acupoint thread-embedding group were lower than those in the model group (P<0.05); the levels of total cholesterol and triacylglycerol in the acupoint thread-embedding group were significantly lower than those in the model group (P<0.01, P<0.05); the weight of epididymal adipose tissue in the acupoint thread-embedding group was significantly lower than that in the model group (P<0.01); the mRNA expression of IL-6, MCP-1, TNF-α and iNOS was reduced (P<0.05), that of IL-10, Arg-1 was increased (P<0.05), the protein expression of iNOS was down-regulated (P<0.05), and that of Arg-1 was up-regulated (P<0.01). CONCLUSION: Acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) may play a role in weight control by regulating the polarization of macrophages.


Assuntos
Pontos de Acupuntura , Epididimo , Tecido Adiposo , Animais , Macrófagos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos
7.
Mitochondrial DNA B Resour ; 5(3): 2605-2606, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-33457877

RESUMO

Selaginella involvens distributed in East Asia region including China used as traditional medicine, which is an important medicinal plant for preventing and treating asthma. The complete chloroplast genome sequence of S. involvens was characterized from Illumina pair-end sequencing. The chloroplast genome of S. involvens was 126,340 bp in length, containing a large single-copy region (LSC) of 53,214 bp, a small single-copy region (SSC) of 47,561 bp, and two inverted repeat (IR) regions of 12,796 bp. The overall GC content is 38.70%, whereas the corresponding values of the LSC, SSC, and IR regions are 36.2%, 31.9%, and 43.2%, respectively. The genome contains 80 complete genes, including 61 protein-coding genes (45 protein-coding gene species), nine tRNA genes (six tRNA species), and eight rRNA genes (four rRNA species). The Neighbour-joining phylogenetic analysis showed that S. involvens and Selaginella tamariscina clustered together as sisters to other Salvia species.

8.
Cell ; 175(4): 1059-1073.e21, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30270039

RESUMO

Motivated by the clinical observation that interruption of the mevalonate pathway stimulates immune responses, we hypothesized that this pathway may function as a druggable target for vaccine adjuvant discovery. We found that lipophilic statin drugs and rationally designed bisphosphonates that target three distinct enzymes in the mevalonate pathway have potent adjuvant activities in mice and cynomolgus monkeys. These inhibitors function independently of conventional "danger sensing." Instead, they inhibit the geranylgeranylation of small GTPases, including Rab5 in antigen-presenting cells, resulting in arrested endosomal maturation, prolonged antigen retention, enhanced antigen presentation, and T cell activation. Additionally, inhibiting the mevalonate pathway enhances antigen-specific anti-tumor immunity, inducing both Th1 and cytolytic T cell responses. As demonstrated in multiple mouse cancer models, the mevalonate pathway inhibitors are robust for cancer vaccinations and synergize with anti-PD-1 antibodies. Our research thus defines the mevalonate pathway as a druggable target for vaccine adjuvants and cancer immunotherapies.


Assuntos
Adjuvantes Imunológicos/farmacologia , Vacinas Anticâncer/imunologia , Difosfonatos/farmacologia , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Ácido Mevalônico/metabolismo , Proteínas rab5 de Ligação ao GTP/antagonistas & inibidores , Animais , Apresentação de Antígeno , Células Apresentadoras de Antígenos/efeitos dos fármacos , Células Apresentadoras de Antígenos/imunologia , Linhagem Celular Tumoral , Endossomos/efeitos dos fármacos , Feminino , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Prenilação de Proteína , Proteínas rab5 de Ligação ao GTP/metabolismo
9.
Biomed Pharmacother ; 105: 491-497, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29883944

RESUMO

Gallic acid is one of the many phenolic acids that can be found in dietary substances and traditional medicine herbs. The anti-cancer activities of gallic acid have been shown in various cancers but its underlying molecular mechanisms are not well understood. In this study, we show Akt/mammalian target of rapamycin (mTOR)-dependent inhibition of mitochondrial respiration as a mechanism of gallic acid's action in acute myeloid leukemia (AML). Gallic acid significantly induces apoptosis of AML cell lines, primary mononuclear cells (MNC) and CD34 stem/progenitors isolated form AML patients via caspase-dependent pathway. It also significantly enhances two standard AML chemotherapeutic agents' efficacy in vitro cell culture system and in vivo xenograft model. Gallic acid inhibits dose- and time-dependent mitochondrial respiration, leading to decreased ATP production and oxidative stress. Overexpression of constitutively active Akt restores gallic acid-mediated inhibition of mTOR signaling, mitochondrial dysfunction, energy crisis and apoptosis. Our results demonstrate that mitochondrial respiration inhibition by gallic acid is a consequence of Akt/mTOR signaling suppression. Our findings suggest that combination therapy with gallic acid may enhance antileukemic efficacy of standard chemotherapeutic agents in AML.


Assuntos
Ácido Gálico/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/patologia , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Ácido Gálico/farmacologia , Humanos , Leucemia Mieloide Aguda/metabolismo , Camundongos Endogâmicos NOD , Camundongos SCID , Mitocôndrias/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
10.
Biochem Biophys Res Commun ; 495(2): 1782-1788, 2018 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-29229390

RESUMO

FamD1 is a novel CloQ/NphB-family indole prenyltransferase which involves in hapalindole-type alkaloid biosynthesis. Here the native FamD1 structure and three protein-ligand complexes are analyzed to investigate the molecular basis of substrate binding and catalysis. FamD1 adopts a typical ABBA architecture of aromatic prenyltransferase, in which the substrate-binding chamber is found in the central ß-barrel. The indole-containing acceptor substrate is bound adjacent to the prenyl donor. Based on the complex structures, a catalytic mechanism of FamD1 is proposed. Functional implications on the sister enzyme FamD2 are also discussed.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Dimetilaliltranstransferase/química , Dimetilaliltranstransferase/metabolismo , Alcaloides Indólicos/metabolismo , Proteínas de Bactérias/genética , Domínio Catalítico , Cristalografia por Raios X , Cianobactérias/enzimologia , Cianobactérias/genética , Dimetilaliltranstransferase/genética , Alcaloides Indólicos/química , Modelos Moleculares , Conformação Proteica , Dobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
11.
Front Immunol ; 8: 1381, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29118758

RESUMO

Activated hepatic stellate cells (aHSCs) are now established as a central driver of fibrosis in human liver injury. In the presence of chronic or repeated injury, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC) can occur, so there is interest in down-regulating aHSCs activity in order to treat these diseases. Here, we report that Vγ9Vδ2 T cells are reduced in patients with liver cirrhosis, stimulating us to investigate possible interactions between Vγ9Vδ2 T cells and aHSCs. We find that Vγ9Vδ2 T cells kill aHSCs and killing is enhanced when aHSCs are pretreated with BPH-1236, a lipophilic analog of the bone resorption drug zoledronate. Cytotoxicity is mediated by direct cell-to-cell contact as shown by Transwell experiments and atomic force microscopy, with BPH-1236 increasing the adhesion between aHSCs and Vγ9Vδ2 T cells. Mechanistically, BPH-1236 functions by inhibiting farnesyl diphosphate synthase, leading to accumulation of the phosphoantigen isopentenyl diphosphate and recognition by Vγ9Vδ2 T cells. The cytolytic process is largely dependent on the perforin/granzyme B pathway. In a Rag2-/-γc-/- immune-deficient mouse model, we find that Vγ9Vδ2 T cells home-in to the liver, and when accompanied by BPH-1236, kill not only orthotopic aHSCs but also orthotopic HCC tumors. Collectively, our results provide the first proof-of-concept of a novel immunotherapeutic strategy for the treatment of fibrosis-cirrhosis-HCC diseases using adoptively transferred Vγ9Vδ2 T cells, combined with a lipophilic bisphosphonate.

12.
Sci Transl Med ; 6(263): 263ra161, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25411474

RESUMO

Lung cancer is the most common human malignancy and leads to about one-third of all cancer-related deaths. Lung adenocarcinomas harboring KRAS mutations, in contrast to those with EGFR and EML4-ALK mutations, have not been successfully targeted. We describe a combination therapy for treating these malignancies with two agents: a lipophilic bisphosphonate and rapamycin. This drug combination is much more effective than either agent acting alone in the KRAS G12D-induced mouse lung model. Lipophilic bisphosphonates inhibit both farnesyl and geranylgeranyldiphosphate synthases, effectively blocking prenylation of KRAS and other small G proteins (heterotrimeric GTP-binding protein, heterotrimeric guanine nucleotide-binding proteins) critical for tumor growth and cell survival. Bisphosphonate treatment of cells initiated autophagy but was ultimately unsuccessful and led to p62 accumulation and concomitant nuclear factor κB (NF-κB) activation, resulting in dampened efficacy in vivo. However, we found that rapamycin, in addition to inhibiting the mammalian target of rapamycin (mTOR) pathway, facilitated autophagy and prevented p62 accumulation-induced NF-κB activation and tumor cell proliferation. Overall, these results suggest that using lipophilic bisphosphonates in combination with rapamycin may provide an effective strategy for targeting lung adenocarcinomas harboring KRAS mutations.


Assuntos
Adenocarcinoma/tratamento farmacológico , Difosfonatos/uso terapêutico , Genes ras , Neoplasias Pulmonares/tratamento farmacológico , Sirolimo/uso terapêutico , Adenocarcinoma/patologia , Animais , Difosfonatos/administração & dosagem , Quimioterapia Combinada , Neoplasias Pulmonares/patologia , Camundongos , Sirolimo/administração & dosagem
13.
Asian Pac J Cancer Prev ; 14(11): 6557-62, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24377567

RESUMO

OBJECTIVE: Specific promoters could improve efficiency and ensure the safety of gene therapy. The aim of our study was to screen examples for lung cancer. METHODS: The firefly luciferase gene was used as a reporter, and promoters based on serum markers of lung cancer were cloned. The activity and specificity of seven promoters, comprising CEACAM5 (carcinoembryonic antigen, CEA), GRP (Gastrin-Releasing Peptide), KRT19 (cytokeratin 19, KRT), SFTPB (surfactant protein B, SP-B), SERPINB3 (Squamous Cell Carcinoma Antigen, SCCA), SELP (Selectin P, Granule Membrane Protein 140 kDa, Antigen CD62, GMP) and DKK1 (Dickkopf-1) promoters were compared in lung cancer cells to obtain cancer-specific examples with strong activity. RESULTS: The CEACAM5, DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB promoters were cloned. Furthermore, we successfully constructed recombinant vector pGL-CEACAM5 (DKK1, GRP, SELP, KRT19, SERPINB3 and SFTPB) contained the target gene. After cells were transfected with recombinant plasmids, we found that the order of promoter activity from high to low was SERPINB3, DKK1, SFTPB, KRT19, CEACAM5, SELP and GRP and the order for promoters regarding specificity and high potential were SERPINB3, DKK1, SELP, SFTPB, CEACAM5, KRT19 and GRP. CONCLUSION: The approach adopted is feasible to screen for new tumour specific promoters with biomarkers. In addition, the screened lung-specific promoters might have potential for use in lung cancer targeted gene therapy research.


Assuntos
Biomarcadores Tumorais/genética , Vetores Genéticos , Luciferases/metabolismo , Neoplasias Pulmonares/genética , Proteínas de Neoplasias/genética , Regiões Promotoras Genéticas/genética , Humanos , Neoplasias Pulmonares/patologia , Células Tumorais Cultivadas
14.
Chem Commun (Camb) ; 49(97): 11379-81, 2013 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-24166648

RESUMO

The synthesis and photophysical characterization of new conjugated polymers (CPs) with alternating phenylethynylene and diazobenzene (azo-PPE) units were reported, which showed broadened absorption and no measurable fluorescence. Quenching studies showed that azo-PPEs displayed high efficiency over a wide wavelength range.


Assuntos
Compostos Azo/química , Corantes Fluorescentes/química , Polímeros/síntese química , DNA/química , DNA/metabolismo , Substâncias Intercalantes/química , Polímeros/química , Espectrofotometria Ultravioleta , Raios Ultravioleta
15.
ACS Appl Mater Interfaces ; 4(8): 3784-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22812479

RESUMO

We report a novel continuous and sensitive fluorescence turn-on assay for ACPs, which consists of a cationic conjugated polyelectrolyte (PPE4+) and a commonly used phosphatase substrate p-nitrophenyl phosphate (pNPP). The kinetics of the ACP catalyzed hydrolysis of the substrate pNPP was monitored by the fluorescence change of PPE4+ and corresponding kinetic parameters were derived to be consistent with the literature reports. The applications of PPE4+/pNPP-based ACP assay in high-throughput screening of ACP inhibitors and detection of prostatic acid phosphotase (PAP) in vitro were demonstrated.


Assuntos
Fosfatase Ácida/química , Eletrólitos/química , Nitrofenóis/química , Compostos Organofosforados/química , Compostos de Anilina/química , Catálise , Desenho de Fármacos , Humanos , Hidrólise , Cinética , Masculino , Modelos Químicos , Monoéster Fosfórico Hidrolases/química , Polímeros/química , Neoplasias da Próstata/diagnóstico , Proteínas Tirosina Fosfatases/química , Espectrometria de Fluorescência/métodos
16.
Protein Pept Lett ; 19(9): 949-54, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22486616

RESUMO

Both fluorescence spectroscopic and molecular docking methods were used to investigate the interaction between bovine serum albumin (BSA) and a known Bcl-xl/Bcl-2 inhibitor HA 14-1. Based on the spectral overlap between the emission of BSA and absorption of HA 14-1, Forster energy transfer was proposed to be the possible quenching mechanism. The Stern-Volmer constants are 2.49 x 104, 2.04 x 104 and 0.90 x 104 M⁻¹ at 293, 303 and 318 K, respectively, indicating that a static quenching process dominates. Thermodynamic parameters were further obtained. The derived negative Δ H (-27.51 kJ mol⁻¹) and Δ S (-11.11 J mol⁻¹ K⁻¹) values suggest hydrogen bond interaction and van der Waals force are the main binding force. The docking study was performed on BSA model. According to the docking score and the number of hydrogen bonds, the potential binding site for HA 14-1 is proposed to be the site IIA, also known as drug site 1.


Assuntos
Benzopiranos/farmacologia , Inibidores Enzimáticos/farmacologia , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Soroalbumina Bovina/metabolismo , Animais , Benzopiranos/química , Sítios de Ligação , Bovinos , Inibidores Enzimáticos/química , Simulação de Acoplamento Molecular , Nitrilas/química , Ligação Proteica , Soroalbumina Bovina/química , Espectrometria de Fluorescência
17.
Analyst ; 137(10): 2309-12, 2012 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-22451893

RESUMO

Label-free fluorescent assays were developed based on the competition of intramolecular DNA hybridization and aptamer-target binding. Using small molecule adenosine triphosphate (ATP) and biomacro-molecule thrombin as model targets, our design was proved to be a general method with good sensitivity and high selectivity.


Assuntos
Aptâmeros de Nucleotídeos/química , Espectrometria de Fluorescência , Trifosfato de Adenosina/análise , Benzotiazóis , DNA/química , DNA/metabolismo , Diaminas , Corantes Fluorescentes/química , Hibridização de Ácido Nucleico , Compostos Orgânicos/química , Quinolinas , Trombina/análise
18.
ACS Appl Mater Interfaces ; 4(1): 405-10, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22128871

RESUMO

We have developed conjugated polyelectrolyte-based fluorescence turn-on assays for caspase 3 and 8. These assays are composed of a cationic polyphenylene ethynylene polymer PPE4+ and p-nitroaniline modified caspase peptide substrate. The fluorescence of the assay is initially turned-off because of the efficient quenching of the polymer by p-nitroaniline moiety on anionic peptide substrates. A turn-on effect is observed due to the cleavage of the peptide by the enzyme and formation of the neutral p-nitroaniline unit which has no quenching on the polymer. We validated this assay design and obtained kinetic parameters of caspase 3 and caspase 8. These assays demonstrated good sensitivity as in pmol/L (0.1 units/mL) for caspase 3 and nmol/L (0.2 units/mL) for caspase 8. This method also showed high specificity by using caspase 3 assay as a model system and the results demonstrated that other proteases including caspase 8, papain, pepsin, and trypsin did not show observable fluorescence turn-on effect. The dose-response curve of a caspase inhibitor Z-VAD-FMK was evaluated by caspase 3 assay, by which the IC(50) value was determined to be 0.73 µM and was in a good agreement with the literature reported value at 0.62 µM. This design could be applied into the in vitro screening of small molecular inhibitors for drug discovery.


Assuntos
Caspase 3/química , Caspase 8/química , Ensaios Enzimáticos/métodos , Ensaios Enzimáticos/instrumentação , Fluorescência , Cinética , Polímeros/química
19.
Bioorg Med Chem ; 18(21): 7507-14, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20863710

RESUMO

A series of novel 9(10H)-acridinone derivatives with terminal amino substituents at C2 position on the acridinone ring were synthesized and studied for their antiproliferative activity and underlying mechanisms. These compounds demonstrated promising cytotoxicity to leukemia cells CCRF-CEM, displaying IC(50) values in the low micromolar range. Structure-activity relationships (SAR) indicated that the compound 6d bearing a pyrrolidine substituent and 8a with a methyl ammonium side chain displayed higher cytotoxicity to CCRF-CEM cells and also solid tumor cells A549, HepG2, and MCF7. Furthermore, the compounds 6d and 8a had strong binding activity to calf thymus DNA (ct DNA), as detected by UV absorption and fluorescence quenching assays, but limited inhibitory activity to human topoisomerase 1 (topo 1). Taken together, this study discovered a series of new synthetic 9(10H)-acridinone derivatives with potent DNA binding and anticancer activity.


Assuntos
Acridinas/química , Antineoplásicos/síntese química , DNA/química , Acridinas/síntese química , Acridinas/toxicidade , Antineoplásicos/química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/metabolismo , Humanos , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/toxicidade
20.
Langmuir ; 26(3): 1528-32, 2010 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-19924894

RESUMO

We investigated the quenching properties of poly(phenylene ethynylene) with anionic alkoxyl sulfonate side groups, PPE-SO3, by tris(2,2-bipyridyl)dichlororuthenium(II) (Rubpy)-doped silica nanoparticles (SiNPs) in water, methanol, and the surfactant Triton X-100 aqueous solution. SiNPs demonstrated hyper-efficient quenching characterized by the Stern-Volmer constants in the range of 10(9)-10(10) M(-1), which is about 100-10,000 times more efficient compared to the Rubpy dye. More importantly, quenching by SiNPs was found to be more efficient when the polymer existed as a nonaggregated state, such as in methanol solution and in the surfactant solution. Investigations on confocal fluorescence images and time-resolved fluorescence decays were carried out to study the quenching mechanism.


Assuntos
Corantes/química , Eletrólitos/química , Nanopartículas/química , Polímeros/química , Dióxido de Silício/química , Absorção , Solventes/química , Análise Espectral , Tensoativos/química
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