Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.166
Filtrar
1.
PLoS Genet ; 16(8): e1008953, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776944

RESUMO

Apoptosis of cochlear hair cells is a key step towards age-related hearing loss. Although numerous genes have been implicated in the genetic causes of late-onset, progressive hearing loss, few show direct links to the proapoptotic process. By genome-wide linkage analysis and whole exome sequencing, we identified a heterozygous p.L183V variant in THOC1 as the probable cause of the late-onset, progressive, non-syndromic hearing loss in a large family with autosomal dominant inheritance. Thoc1, a member of the conserved multisubunit THO/TREX ribonucleoprotein complex, is highly expressed in mouse and zebrafish hair cells. The thoc1 knockout (thoc1 mutant) zebrafish generated by gRNA-Cas9 system lacks the C-startle response, indicative of the hearing dysfunction. Both Thoc1 mutant and knockdown zebrafish have greatly reduced hair cell numbers, while the latter can be rescued by embryonic microinjection of human wild-type THOC1 mRNA but to significantly lesser degree by the c.547C>G mutant mRNA. The Thoc1 deficiency resulted in marked apoptosis in zebrafish hair cells. Consistently, transcriptome sequencing of the mutants showed significantly increased gene expression in the p53-associated signaling pathway. Depletion of p53 or applying the p53 inhibitor Pifithrin-α significantly rescued the hair cell loss in the Thoc1 knockdown zebrafish. Our results suggested that THOC1 deficiency lead to late-onset, progressive hearing loss through p53-mediated hair cell apoptosis. This is to our knowledge the first human disease associated with THOC1 mutations and may shed light on the molecular mechanism underlying the age-related hearing loss.


Assuntos
Proteínas de Ligação a DNA/genética , Surdez/genética , Células Ciliadas Auditivas Internas/metabolismo , Proteínas de Ligação a RNA/genética , Proteína Supressora de Tumor p53/genética , Animais , Apoptose/genética , Benzotiazóis/farmacologia , Proteína 9 Associada à CRISPR/genética , Proteínas de Ligação a DNA/deficiência , Surdez/patologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas/patologia , Células Ciliadas Auditivas Internas/patologia , Humanos , Camundongos , Mutação , RNA Guia/genética , Transdução de Sinais/efeitos dos fármacos , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Sequenciamento Completo do Exoma , Peixe-Zebra/genética
2.
Ecotoxicol Environ Saf ; 205: 111138, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32836156

RESUMO

Nitrobenzene, nitrotoluenes and nitrobenzoic acid are toxic and mutagenic. Their removal from the environment is necessary to avoid health and environmental damage. In this study, Cupriavidus strain a3 was found to utilize 2-nitrotoluene (2NT), 3-nitrotoluene (3NT), 4-nitrotoluene (4NT), nitrobenzene (NB) and 2-nitrobenzoic acid (2NBA) as carbon and nitrogen source, resulting in their detoxification. The metabolism involved reductive transformation of nitroaromatics to the corresponding amines followed by cleavage of amino group to release ammonia. Cell free extract showed nitroreductase activity in the range of 310-389 units/mg. NB was reduced to form benzamine and 4-aminophenol, 2NT was reduced to 2-aminotoluene, whereas 2NBA was reduced to form 2-aminobenzoic acid. Similarly, 3NT was metabolized to 3-aminotoluene and 2-amino-4-methylphenol, while 4NT was reduced to 4-nitrosotoluene and 4-aminotoluene. Cytotoxicity and apoptosis assays using Jurkat cell line, and Ames test were used to evaluate the detoxification of nitroaromatics during biodegradation. Biodegradation with Cupriavidus resulted in 2.6-11 fold increase in cell viability, 1.3-2.3 fold reduction in apoptosis, 1.6-55 fold reduction in caspase-3 activation, and complete disappearance of mutagenic activity. In soil microcosm, bioaugmentation with Cupriavidus resulted in 16-59% degradation of various nitroaromatics, as against <14% degradation without bioaugmentation. Thus, the present study reflects promising capability of Cupriavidus strain a3 in degradation and detoxification of multiple nitroaromatics.


Assuntos
Biodegradação Ambiental , Cupriavidus/fisiologia , Poluentes Ambientais/metabolismo , Nitrobenzenos , Solo , Tolueno/análogos & derivados , Toluidinas
3.
PLoS Negl Trop Dis ; 14(5): e0008339, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32437349

RESUMO

Trypanothione reductase (TR) is a key enzyme that catalyzes the reduction of trypanothione, an antioxidant dithiol that protects Trypanosomatid parasites from oxidative stress induced by mammalian host defense systems. TR is considered an attractive target for the development of novel anti-parasitic agents as it is essential for parasite survival but has no close homologue in humans. We report here the identification of spiro-containing derivatives as inhibitors of TR from Trypanosoma brucei (TbTR), the parasite responsible for Human African Trypanosomiasis. The hit series, identified by high throughput screening, was shown to bind TbTR reversibly and to compete with the trypanothione (TS2) substrate. The prototype compound 1 from this series was also found to impede the growth of Trypanosoma brucei parasites in vitro. The X-ray crystal structure of TbTR in complex with compound 1 solved at 1.98 Å allowed the identification of the hydrophobic pocket where the inhibitor binds, placed close to the catalytic histidine (His 461') and lined by Trp21, Val53, Ile106, Tyr110 and Met113. This new inhibitor is specific for TbTR and no activity was detected against the structurally similar human glutathione reductase (hGR). The central spiro scaffold is known to be suitable for brain active compounds in humans thus representing an attractive starting point for the future treatment of the central nervous system stage of T. brucei infections.


Assuntos
Antiprotozoários/farmacologia , Inibidores Enzimáticos/farmacologia , NADH NADPH Oxirredutases/antagonistas & inibidores , Tolueno/análogos & derivados , Trypanosoma brucei brucei/efeitos dos fármacos , Antiprotozoários/isolamento & purificação , Sítios de Ligação , Cristalografia por Raios X , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/isolamento & purificação , Ensaios de Triagem em Larga Escala , NADH NADPH Oxirredutases/química , Ligação Proteica , Conformação Proteica , Tolueno/isolamento & purificação , Tolueno/farmacologia , Trypanosoma brucei brucei/enzimologia
4.
Sci Rep ; 10(1): 1049, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31974452

RESUMO

Pifithrin-α (PFT-α) is a small molecule which has been widely used as a specific inhibitor of p53 transcription activity. However, its molecular mechanism of action remains unclear. PFT-α has also been described to display potent p53-independent activity in cells. In this study, we addressed the mechanism of action of PFT-α. We found that PFT-α failed to prevent the effects of Mdm2 inhibitor Nutlin-3 on cell cycle and apoptosis in several cancer cell lines. However, PFT-α rescued normal primary fibroblasts from growth inhibition by Nutlin-3. PFT-α displayed a very limited effect on p53-dependent transcription upon its activation by Nutlin-3. Moreover, PFT-α inhibitory effect on transcription was highly dependent on the nature of the p53 target gene. PFT-α attenuated post-translational modifications of p53 without affecting total p53 protein level. Finally, we found that PFT-α can decrease the level of intracellular reactive oxygen species through activation of an aryl hydrocarbon receptor (AHR)-Nrf2 axis in a p53-independent manner. In conclusion, PFT-α inhibits only some aspects of p53 function, therefore it should be used with extreme caution to study p53-dependent processes.


Assuntos
Benzotiazóis/farmacologia , Imidazóis/metabolismo , Piperazinas/metabolismo , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Tolueno/análogos & derivados , Transcrição Genética/efeitos dos fármacos , Proteína Supressora de Tumor p53/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células HCT116 , Humanos , Células MCF-7 , Fator 2 Relacionado a NF-E2/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/genética , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Interferência de RNA , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Tolueno/farmacologia , Transcrição Genética/genética , Proteína Supressora de Tumor p53/metabolismo
5.
Inorg Chem ; 59(2): 968-971, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31891256

RESUMO

A dithiolate/hydride bridged Fe-Ni complex, [(CN)(CO)2FeII(µ-pdt)(µ-H)NiII(CN)(PCy3)]- (2, pdt = propane-1,3-dithiolate) has been synthesized by the reaction of [(CN)2(CO)2FeII(pdt)]2- with [NiII(Cl)(H)(PCy3)2] as a synthetic analogue of the Ni-R state of the active site of the [Ni-Fe] hydrogenase. X-ray crystallography of this model complex suggests that the hydride unsymmetrically binds to Ni and Fe similar to natural [Ni-Fe] hydrogenases.


Assuntos
Monóxido de Carbono/química , Complexos de Coordenação/química , Cianetos/química , Hidrogenase/química , Tolueno/análogos & derivados , Monóxido de Carbono/metabolismo , Domínio Catalítico , Complexos de Coordenação/metabolismo , Cianetos/metabolismo , Hidrogenase/metabolismo , Ferro/química , Ferro/metabolismo , Modelos Moleculares , Conformação Molecular , Níquel/química , Níquel/metabolismo , Tolueno/química , Tolueno/metabolismo
6.
Chem Commun (Camb) ; 55(83): 12487-12490, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31566647

RESUMO

CF2H-Pseudoprolines obtained from difluoroacetaldehyde hemiacetal and serine are stable proline surrogates. The consequence of the incorporation of the CF2H group is an important decrease of the trans to cis amide bond isomerization energy and a remarkable stabilisation of the cis conformer by an hydrogen bond.


Assuntos
Peptídeos/química , Prolina/análogos & derivados , Tiazóis/química , Tolueno/análogos & derivados , Ligação de Hidrogênio , Metilação , Conformação Molecular , Prolina/química , Estereoisomerismo , Tolueno/química
7.
Chemistry ; 25(50): 11641-11645, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31338883

RESUMO

Ibuprofen was prepared from an inactive and inexpensive p-xylene by three-step flow functionalizations through chemoselective metalations of benzyl positions in sequence using an in situ generated LICKOR-type superbase. The flow approach in the microreactor facilitated the comprehensive exploration of over 100 conditions in the first-step reaction by varying concentrations, temperatures, solvents, and equivalents of reagents, enabling optimal conditions to be found with 95 % yield by significantly suppressing the formation of byproducts, followed by the second C-H metalation step in 95 % yield. Moreover, gram-scale synthesis of ibuprofen in the final step was achieved by biphasic flow reaction of solution-phase intermediate with CO2 , isolating 2.3 g for 10 min of operation time.


Assuntos
Ibuprofeno/química , Metais/química , Xilenos/química , Carbono/química , Hidrogênio/química , Ibuprofeno/síntese química , Tolueno/análogos & derivados , Tolueno/química
8.
Anal Sci ; 35(11): 1221-1226, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31327816

RESUMO

In this study, we developed an electrochemical sensor for ochratoxin A (OTA) by using an aptamer having a dithiol-based anchor, which exhibited higher stability on a gold electrode than a monothiol-based aptamer because of its two anchors. The sensor was also based on a signal-on scheme that produces a signal current resulting from structure-switching of the aptamer upon interaction with OTA. For simple fabrication of this sensor, the non-covalent interaction of methylene blue with the aptamer was also employed as an electrochemical indicator. In this study, the performance of the sensor, including the dissociation constant of the aptamer-OTA complex, was characterized. The proposed sensor exhibited high reproducibility and enough sensitivity to detect the minimum amount of OTA required for the analysis of real food samples with a limit of detection of 113 pM.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Ocratoxinas/análise , Tolueno/análogos & derivados , Aptâmeros de Nucleotídeos/genética , Aptâmeros de Nucleotídeos/metabolismo , Sequência de Bases , Eletroquímica , Limite de Detecção , Ocratoxinas/metabolismo , Tolueno/química
9.
Neurotox Res ; 36(2): 347-356, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31069753

RESUMO

Methamphetamine (Meth) is a widely abused stimulant. High-dose Meth induces degeneration of dopaminergic neurons through p53-mediated apoptosis. A recent study indicated that treatment with the p53 inhibitor, pifithrin-alpha (PFT-α), antagonized Meth-mediated behavioral deficits in mice. The mechanisms underpinning the protective action of PFT-α against Meth have not been identified, and hence, their investigation is the focus of this study. Primary dopaminergic neuronal cultures were prepared from rat embryonic ventral mesencephalic tissue. High-dose Meth challenge reduced tyrosine hydroxylase immunoreactivity and increased terminal deoxynucleotidyl transferase-mediated dNTP nick-end labeling (TUNEL) labeling. PFT-α significantly antagonized these responses. PFT-α also reduced Meth-activated translocation of p53 to the nucleus, an initial step before transcription. Previous studies have indicated that p53 can also activate cell death through transcription-independent pathways. We found that PFT-α attenuated endoplasmic reticulum (ER) stressor thapsigargin (Tg)-mediated loss of dopaminergic neurons. ER stress was further monitored through the release of Gaussia luciferase (GLuc) from SH-SY5Y cells overexpressing GLuc-based Secreted ER Calcium-Modulated Protein (GLuc-SERCaMP). Meth or Tg significantly increased GLuc release in to the media, with PFT-α significantly reducing GLuc release. Additionally, PFT-α significantly attenuated Meth-induced CHOP expression. In conclusion, our data indicate that PFT-α is neuroprotective against Meth-mediated neurodegeneration via transcription-dependent nuclear and -independent cytosolic ER stress pathways.


Assuntos
Benzotiazóis/farmacologia , Estimulantes do Sistema Nervoso Central/toxicidade , Neurônios Dopaminérgicos/efeitos dos fármacos , Metanfetamina/toxicidade , Tolueno/análogos & derivados , Animais , Linhagem Celular Tumoral , Células Cultivadas , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Estresse do Retículo Endoplasmático/fisiologia , Feminino , Humanos , Gravidez , Ratos , Tolueno/farmacologia
10.
Methods Mol Biol ; 1967: 295-304, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069779

RESUMO

Conjugates of 4-(N-(S-glutathionylacetyl)amino)phenylarsonous acid (GSAO) with optical or radionuclide probes are able to image cell death in vivo. GSAO conjugates are retained in the cytosol of dying and dead cells via the formation of covalent bonds between the As(III) ion and the thiol groups of proximal cysteine residues. Here we describe the method for preparing a NODAGA-GSAO conjugate and its radiolabeling with gallium-68 (68Ga-NODAGA-GSAO) for positron-emission tomography (PET) imaging of cell death.


Assuntos
Morte Celular/genética , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/química , Tolueno/análogos & derivados , Acetatos/química , Acetatos/uso terapêutico , Animais , Arsenicais/química , Arsenicais/uso terapêutico , Radioisótopos de Gálio/química , Radioisótopos de Gálio/uso terapêutico , Glutationa/análogos & derivados , Glutationa/química , Glutationa/uso terapêutico , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/uso terapêutico , Humanos , Radioisótopos/administração & dosagem , Radioisótopos/química , Compostos Radiofarmacêuticos/uso terapêutico , Tolueno/química
11.
Methods Mol Biol ; 1967: 305-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31069780

RESUMO

Flow cytometry assessment of platelets using the combination of GSAO [4-(N-(S-glutathionylacetyl)amino)phenylarsonous acid], a dithiol-reactive probe, and P-selectin, a platelet activation marker, is a novel and powerful assay in the identification and quantification of the procoagulant subpopulation of platelets that has the capacity to support thrombin generation. In this chapter, we provide the flow cytometry protocols aimed at the study of procoagulant platelets under resting and agonist-stimulated conditions in whole blood and washed platelets of both human and murine (mouse) samples.


Assuntos
Plaquetas/química , Citometria de Fluxo/métodos , Tolueno/análogos & derivados , Animais , Humanos , Camundongos , Selectina-P/química , Selectina-P/genética , Ativação Plaquetária/efeitos dos fármacos , Trombina/química , Tolueno/química
12.
J Biomater Sci Polym Ed ; 30(8): 662-678, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30947639

RESUMO

Proteins are ideal raw materials for preparing biomaterials with better biocompatibility and larger elastic range than synthetic polymers. Injectable hydrogels are highly desired for minimal invasive strategies. At present, preparation of injectable hydrogels with good comprehensive properties using natural materials receives more and more attention. In this article, BSA was treated with urea and glutathione to prepare bovine serum albumin hydrogel controlled by two dynamic equilibrium bonds (disulfide and hydrogen bonds). The hydrogen bond equilibrium between urea-protein and protein-protein as well as the exchange reaction equilibrium between thiol-disulfide bonds in the system not only facilitated to enhance the mechanical properties, but also to reduce the gelation time to 5 min. Moreover, this novel albumin hydrogel was proved to be of good biocompatibility. Therefore, the albumin hydrogels in this article were injectable within the physiological range and shown low cytotoxicity, good machanical property ( storage modulus could be greater than 10 kPa and compressive stress could reach 0.2 MPa) and good injectability, which exhibited promising prospect.


Assuntos
Reagentes para Ligações Cruzadas/química , Glutationa/química , Hidrogéis/química , Soroalbumina Bovina/química , Ureia/química , Adesão Celular , Linhagem Celular , Sobrevivência Celular , Humanos , Ligação de Hidrogênio , Injeções , Cinética , Desnaturação Proteica , Reologia , Propriedades de Superfície , Tolueno/análogos & derivados , Tolueno/química , Água
13.
Vet Microbiol ; 232: 1-12, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31030832

RESUMO

Porcine epidemic diarrhea virus (PEDV) is a member of Coronavirus, which causes severe watery diarrhea in piglets with high morbidity and mortality. ROS and p53 play key roles in regulating many kinds of cell process during viral infection, however, the exact function in PEDV-induced apoptosis remains unclear. In this study, the pro-apoptotic effect of PEDV was examined in Vero cells and we observed that PEDV infection increased MDM2 and CBP, promoted p53 phosphorylation at serine 20 and, promoted p53 nuclear translocation, leading to p53 activation in Vero cells. Treatment with the p53 inhibitor PFT-α could significantly inhibit PEDV-induced apoptosis. We also observed PEDV infection induced time-dependent ROS accumulation. Treatment with antioxidants, such as pyrrolidine dithiocarbamate (PDTC) or N-acetylcysteine (NAC), significantly inhibited PEDV-induced apoptosis. Moreover, further inhibition tests were established to prove that p53 was regulated by ROS in PEDV-induced apoptosis. In addition, we also found that p38 MAPK and SAPK/JNK were activated in PEDV-infected Vero cells. However, treatment with the p38 MAPK inhibitor SB203580, and the SAPK/JNK inhibitor SP600125 reversed PEDV-induced apoptosis. Taken together, the results of this study demonstrate that activated p53 and accumulated ROS participated in PEDV-induced apoptosis and p53 could be regulated by ROS during PEDV infection. Activated p38 MAPK and SAPK/JNK exerted no influence on PEDV-induced apoptosis. These findings provide new insights into the function of p53 and ROS in the interaction of PEDV with Vero cells.


Assuntos
Apoptose , Sistema de Sinalização das MAP Quinases , Vírus da Diarreia Epidêmica Suína/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acetilcisteína/farmacologia , Animais , Benzotiazóis/farmacologia , Chlorocebus aethiops , Pirrolidinas/farmacologia , Tiocarbamatos/farmacologia , Tolueno/análogos & derivados , Tolueno/farmacologia , Células Vero , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Environ Monit Assess ; 191(5): 309, 2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31028555

RESUMO

To enhance our understanding on environmental conditions of the Maowei Sea in Guangxi province, China, the concentration and distribution of 22 chlorobenzene compounds (CBs) in the surface sediment were determined by gas chromatography-mass spectrometry (GC-MS). The relationship of the sediment between CBs and total organic carbon (TOC) was also investigated. The results showed that a total of eight kinds of CBs compounds were detected in the sediment samples which were collected from the coastal environment of the Maowei Sea, with an average concentration of 15.3 ng·g-1 (the concentration range, 2.5-61.5 ng·g-1). The rank of their average concentrations was as follows: 2,3,4,5,6-pentachlorotoluene > hexachlorobenzene, 2-chlorotoluene, 3-chlorotoluene and 2,3-dichlorotoluene > 2,4-dichlorotoluene > 4-chlorotoluene > pentachlorobenzene. Most CBs were distributed in sediments along the east coast of the Maowei Sea. For total TOC content in sediments, the concentration in the sampling locations was similar, with a mean concentration of 8.83 g·kg-1 (the concentration range, 4.87-20.13 g·kg-1). However, there was no significant correlation between the concentration of TOC and total CBs. Compared to the corresponding CBs in the sediment of other coastal areas in mainland China and other countries, the value of CBs in the Maowei Sea was low.


Assuntos
Clorobenzenos/análise , Monitoramento Ambiental , Sedimentos Geológicos/química , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , China , Ecologia , Cromatografia Gasosa-Espectrometria de Massas , Hexaclorobenzeno/análise , Oceanos e Mares , Tolueno/análogos & derivados , Tolueno/análise
15.
J Parasitol ; 105(1): 146-154, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807708

RESUMO

To evaluate the effect of mitogen-activated protein kinase (MAPK) signal transduction pathway inhibitors against alveolar echinococcosis in vitro and in vivo, Echinococcus multilocularis metacestode cysts and protoscolices were obtained from infected mice. Protein chip technology was utilized to screen for key highly expressed target proteins in the MAPK pathway in this parasite and their corresponding inhibitors. Four-week-old Balb/c female mice used for the in vivo experiment underwent inoculation of E. multilocularis by intraperitoneal injection, as well as intragastric administration of MAPK inhibitors for 6 wk. We included 6 groups of mice: a phosphate-buffered saline (PBS) group (negative control); an albendazole-treated group (positive group); and 4 experimental groups treated with TRx0237 mesylate, GDC-0994, pifithrin-ß hydrobromide, or Selonsertib. Echinococcus multilocularis protoscolices were collected and cultured in 1066 medium with penicillin/streptomycin and 10% fetal bovine serum. The in vitro experiment included a PBS group (negative control), a dimethyl sulfoxide-treated group (solvent group), and 4 inhibitor-treated groups as in the in vivo experiment (experimental groups). Each inhibitor group received 4 drug concentrations (5, 30, 55, and 80 µM), and the experiment was performed in triplicate per sample. Fluorescence microscopy was used to evaluate the survival rate of the protoscolices every 48 hr beginning from the first 24 hr. The same grouping was used to evaluate cytotoxicity on E. multilocularis germinal cells and L02 cells. The average weights of E. multilocularis metacestode cyst tissue from each group of the in vivo experiment were 873 mg (PBS), 335 mg (albendazole), 323 mg (TRx0237 mesylate), 420 mg (GDC-0994), 340 mg (pifithrin-ß hydrobromide), and 642 mg (Selonsertib). Results showed albendazole, TRx0237 mesylate, and pifithrin-ß hydrobromide had significant inhibitory effects on inhibition of E. multilocularis. We found a positive correlation between drug concentrations and the inhibitory effects seen in the in vitro experiment, with the differences in contrast with the control group becoming statistically significant after 72 hr of treatment ( P < 0.05). The inhibition rates of TRx0237 mesylate to germinal cells by drug concentration were 23.73, 46.59, 74.71, and 77.44%. Other drugs had no effect on germinal cells. All the inhibitors had low toxicity on L02 cells. Inhibitors of the MAPK signal transduction pathway showed significant inhibitory effects on E. multilocularis, suggesting these may be potential candidates for the treatment of alveolar echinococcosis.


Assuntos
Anti-Helmínticos/farmacologia , Equinococose/tratamento farmacológico , Echinococcus multilocularis/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Albendazol/farmacologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/química , Anti-Helmínticos/uso terapêutico , Benzamidas/química , Benzamidas/farmacologia , Benzamidas/uso terapêutico , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Modelos Animais de Doenças , Equinococose/enzimologia , Feminino , Hepatócitos/parasitologia , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Humanos , Imidazóis/química , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Concentração Inibidora 50 , Azul de Metileno/análogos & derivados , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Análise Serial de Proteínas , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/química , Piridinas/farmacologia , Piridinas/uso terapêutico , Tolueno/análogos & derivados , Tolueno/química , Tolueno/farmacologia , Tolueno/uso terapêutico
16.
Am J Physiol Renal Physiol ; 316(4): F674-F681, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30698046

RESUMO

The cyclin kinase inhibitor p21 is acutely upregulated during acute kidney injury (AKI) and exerts cytoprotective effects. A proposed mechanism is oxidant stress-induced activation of p53, the dominant p21 transcription factor. Glycerol-induced rhabdomyolysis induces profound renal oxidant stress. Hence, we studied this AKI model to determine whether p53 activation corresponds with p21 gene induction and/or whether alternative mechanism(s) might be involved. CD-1 mice were subjected to glycerol-induced AKI. After 4 or 18 h, plasma, urinary, and renal cortical p21 protein and mRNA levels were assessed. Renal p53 activation was gauged by measurement of both total and activated (Ser15-phosphorylated) p53 and p53 mRNA levels. Glycerol evoked acute, progressive increases in renal cortical p21 mRNA and protein levels. Corresponding plasma (~25-fold) and urinary (~75-fold) p21 elevations were also observed. Renal cortical ratio of total to phosphorylated (Ser15) p53 rose three- to fourfold. However, the p53 inhibitor pifithrin-α failed to block glycerol-induced p21 gene induction, suggesting that an alternative p21 activator might also be at play. To this end, it was established that glycerol-induced AKI 1) dramatically increased plasma (~5-fold) and urinary (~75-fold) cortisol levels, 2) the glucocorticoid receptor antagonist mifepristone blocked glycerol-induced p21 mRNA and protein accumulation, and 3) dexamethasone or cortisol injections markedly increased p21 protein and mRNA in both normal and glycerol-treated mice, although no discernible p53 protein or mRNA increases were observed. We conclude that AKI-induced "systemic stress" markedly increases plasma and urinary cortisol, which can then activate renal p21 gene expression, at least in part, via a glucocorticoid receptor-dependent signaling pathway. Discernible renal cortical p53 increases are not required for this dexamethasone-mediated p21 response.


Assuntos
Lesão Renal Aguda/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Glucocorticoides/metabolismo , Transdução de Sinais , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/fisiopatologia , Animais , Benzotiazóis/uso terapêutico , Dexametasona/uso terapêutico , Glicerol , Antagonistas de Hormônios/uso terapêutico , Hidrocortisona/sangue , Hidrocortisona/uso terapêutico , Hidrocortisona/urina , Córtex Renal/metabolismo , Masculino , Camundongos , Mifepristona/uso terapêutico , Tolueno/análogos & derivados , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima
17.
Biomater Sci ; 7(2): 607-617, 2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30462102

RESUMO

Stimuli-responsive nanogels are important drug and gene carriers that mediate the controlled release of therapeutic molecules. Herein, we report the synthesis of fully degradable disulfide cross-linked nanogel drug carriers formed by oxidative radical polymerization of 2,2'-(ethylenedioxy)diethanethiol (EDDET) as a monomer with different cross-linkers, including pentaerythritol tetramercaptoacetate (PETMA). Because the poly(EDDET) backbone repeat structure and cross-linking junctions are composed entirely of disulfide bonds, these nanogels specifically degrade to small molecule dithiols intracellularly in response to the reducing agent glutathione present inside of cells. Cross-linked nanogels were synthesized using controlled microfluidic mixing in the presence of a nonionic Pluronic surfactant PLU-127 to increase the nanogel stability. Adjusting the monomer to cross-linker ratio from 5 : 1 to 100 : 1 (mol/mol) tuned the cross-linking density, resulting in swelling ratios from 1.65 to >3. Increasing the amount of stabilizing Pluronic surfactant resulted in a decrease of nanogel diameter, as expected due to increased surface area of the resulting nanogels. The monomer to cross-linker ratio in the feed had no effect on the formed nanogel diameter, providing a way to control cross-linking density with constant nanogel size but tunable drug release kinetics. Nanogels exhibited an entrapment efficiency of up to 75% for loading of Rhodamine B dye. In vitro studies showed low cytotoxicity, quick uptake, and fast degradation kinetics. Due to the ease of synthesis, rapid gelation times, and tunable functionality, these non-toxic and fully degradable nanogels offer potential for use in a variety of drug delivery applications.


Assuntos
Dissulfetos/química , Portadores de Fármacos/química , Nanoestruturas/química , Polimerização , Tolueno/análogos & derivados , Transporte Biológico , Portadores de Fármacos/metabolismo , Portadores de Fármacos/toxicidade , Géis , Células HeLa , Humanos , Cinética , Oxirredução , Tensoativos/química , Tolueno/química
18.
Biosens Bioelectron ; 129: 284-291, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30245166

RESUMO

Silica nanopores have electron channels and ion channels interpenetrating each other, which prompt the use of this structure for creating efficient electronic devices. In this study, silica nanopores membrane modified screen printed electrodes were applied in a smartphone-based electrochemiluminescence system for nitroaromatic explosives detection. Universal serial bus-on the go (USB-OTG) and camera on smartphone were used as the electrical stimulation and luminescence capture, respectively. ⎕Multimode methods including (red-green-blue) RGB, (hue-saturation-brightness) HSB, and Gray were proposed for luminescence analysis. Specific polypeptides were immobilized on the nanopores modified electrodes for nitroaromatic explosives sensing. With positive-charged tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)32+) as electrochemiluminescence label, the increase in luminescence was associated with the selective ion channels and the well-conductive electron channels in the negative-charged nanopores. Besides, on account of the large specific surface area, nanopores modified screen printed electrodes showed stable and uniform luminescence. Results showed that the nanopores-enhanced electrochemiluminescence on smartphone covered a linear dynamic range from 10-7 mg/mL to 10-3 mg/mL for nitroaromatic explosives detection with the detection limit of 2.3 × 10-9 mg/mL. Therefore, high-efficient photo-electricity conversion capabilities of nanopores made it a kind of promising platform for sensitive and stable electrochemiluminescence. Furthermore, smartphone-based electrochemiluminescence with disposable screen printed electrodes could facilitate the mobile monitoring of biochemical analytes in the fields of environment, security, and health.


Assuntos
Técnicas Biossensoriais/instrumentação , Dinitrobenzenos/análise , Substâncias Explosivas/análise , Nanoporos/ultraestrutura , Dióxido de Silício/química , Tolueno/análogos & derivados , Trinitrotolueno/análise , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Limite de Detecção , Medições Luminescentes/instrumentação , Peptídeos/química , Smartphone , Tolueno/análise
19.
FASEB J ; 33(1): 844-856, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30052487

RESUMO

Aging of white adipose tissue (WAT) is associated with reduced insulin sensitivity, which contributes to whole-body glucose intolerance. WAT aging in mice impairs cold-induced beige adipocyte recruitment (beiging), which has been attributed to the senescence of adipose progenitor cells. Tumor suppressor p53 has also been implicated in WAT aging. However, whether p53-related cellular aging in mature white adipocytes is causative of age-impaired WAT beiging remains unknown. It is also unclear whether transient p53 inhibition can rescue WAT beiging. Herein, we report that p53 increased in adipose tissues of 28-wk-old (aged) mice with impaired beiging capability. Cold exposure decreased p53 in beiging WAT of young mice but not in aged mice. In aged mice, inducible p53 ablation in differentiated adipocytes restored cold-induced WAT beiging and augmented whole-body energy expenditure and insulin sensitivity. Transient pharmacological inhibition of p53 led to the same beneficial effects. Mechanistically, cold exposure repressed autophagy in beiging WAT of young mice yet increased autophagy in aged WAT. p53-ablation reduced microtubule-associated protein light chain 3-mediated mitochondria clearance (mitophagy) and hence facilitated the increase of mitochondria during beiging. These findings suggest that p53-induced mitophagy in aged white adipocytes impedes WAT beiging and may be therapeutically targeted to improve insulin sensitivity in aged WAT.-Fu, W., Liu, Y., Sun, C., Yin, H. Transient p53 inhibition sensitizes aged white adipose tissue for beige adipocyte recruitment by blocking mitophagy.


Assuntos
Adipócitos Bege/metabolismo , Tecido Adiposo Branco/metabolismo , Envelhecimento/metabolismo , Mitofagia , Proteína Supressora de Tumor p53/metabolismo , Adipócitos Bege/citologia , Adipócitos Bege/efeitos dos fármacos , Adiponectina/genética , Adiposidade , Animais , Benzotiazóis/farmacologia , Células Cultivadas , Temperatura Baixa , Metabolismo Energético , Resistência à Insulina , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Sirolimo/farmacologia , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores
20.
Eur J Pharm Sci ; 128: 61-72, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30472223

RESUMO

p53 is generally known as an effective anti-cancer molecular, but it is lost or mutated in more than 50% of human tumors. It is still a controversial issue whether the activity of p53 really benefits for treating cancers, we wondered what would happen if the endogenous p53 was inhibited before treated with topotecan (TPT) on p53 positive tumor cells. In this study, pifithrin-α (PFTα), a p53 inhibitor, was used 2 h before treated with TPT on three kinds of cancer cell lines including MCF7, BGC823 and HepG2 cells. The IC50s of TPT for MCF7, BGC823 and HepG2 cells after 10 µΜ PFTα pretreated, was 4.8 to 14.4 folds lower than the effect of TPT alone. It was demonstrated that PFTα decreases the p-p53 levels and p-p53 activity, not affects p53 expression in p53 positive tumor cells. PFTα enhanced anticancer effect of TPT on cells was found mainly by two ways. Firstly, it increased the TPT accumulation in cells and nucleus and promoted the inhibition of TPT on activity of Topo I, and induced more DNA damage. Secondly, PFTα decreased formation of p53/mdm2 complex responsible for p53 degradation by inhibiting the protein expression of mdm2, so p53 degradation was decreased in cytoplasm and p53 accumulation was increased in nucleus, which induced more cells undergo apoptosis. So, the crosstalk between p53 and TPT played a pivotal role for enhancing anticancer effects of PFTα and TPT on p53 positive cancer cells. These findings provide a new idea for drug design and combination chemotherapy of cancers.


Assuntos
Benzotiazóis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Tolueno/análogos & derivados , Topotecan/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Benzotiazóis/administração & dosagem , Benzotiazóis/química , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Estrutura Molecular , Tolueno/administração & dosagem , Tolueno/química , Tolueno/farmacologia , Proteína Supressora de Tumor p53/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA