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1.
RSC Adv ; 14(20): 13801-13807, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38681838

RESUMO

Near-infrared red (NIR) fluorescence imaging guide phototherapeutic therapy (PDT) has the advantages of deep tissue penetration, real-time monitoring of drug treatment and disease, little damage to normal tissue, low cytotoxicity and almost no side effects, and thus, it is attracting increasing research attention and is expected to show promising potential for clinical tumor treatment. The photosensitizer (PS), light source and oxygen are the three basic and important factors to construct PDT technology, and highly efficient PSs are still being passionately pursued because they determine the PDT efficiency. Ideal PSs should have properties such as good biocompatibility, deep tissue penetration, and highly efficient reactive oxygen species (ROS) generation despite the hypoxic environment. Therefore, pure organic type I PSs with NIR fluorescence have been receiving increasing attention due to their deep penetration and hypoxia resistance. However, reported NIR-active type I PSs usually require complex synthetic procedures, which presents a challenge for mass production. In this research work, based on the molecular design ideas of introducing the heavy atom effect and intramolecular charge transfer, we prepared three NIR-active type I PSs (TNZ, TNZBr, and TNZCHO) using a very simple method with one or two synthetic steps. Clear characterizations of photophysical properties, ROS performance tests, and fluorescent imaging of human umbilical vein endothelial (HUVE) cells and PDT treatment of HepG2 cells were carried out. The results revealed that the heavy atom and intramolecular charge transfer (ICT) effects could obviously enhance the ROS efficiency, and both PSs produce only type I ROS without any type II ROS (1O2) generation. The good NIR fluorescence brightness and type I ROS efficiency ensure satisfactory bioimaging and PDT outcomes. This research provides the possibility of preparing NIR-active type I PSs via mass production.

2.
Luminescence ; 39(1): e4621, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38044321

RESUMO

Near-infrared (NIR) fluorescence imaging-guided photodynamic therapy (PDT) technology plays an important role in treating various diseases and still attracts increasing research interests for developing novel photosensitizers (PSs) with outstanding performances. Conventional PSs such as porphyrin and rhodamine derivatives have easy self-aggregation properties in the physiological environment due to their inherent hydrophobic nature caused by their rigid molecular structure that induces strong intermolecular stacking π-π interaction, leading to serious fluorescence quenching and cytotoxic reactive oxygen species (ROS) reduction. Meanwhile, hypoxia is an inherent barrier in the microenvironment of solid tumors, seriously restricting the therapeutic outcome of conventional PDT. Aforementioned disadvantages should be overcome urgently to enhance the therapeutic effect of PSs. Novel NIR fluorescence-guided type I PSs with aggregation-induced emission (AIE), which features the advantages of improving fluorescent intensity and ROS generation efficiency at aggregation as well as outstanding oxygen tolerance, bring hope for resolving aforementioned problems simultaneously. At present, plenty of research works fully demonstrates the advancement of AIE-active PDT based on type I PSs. In this review, cutting-edge advances focusing on AIE-active NIR type I PSs that include the aspects of the photochemical mechanism of type I ROS generation, various molecular structures of reported type I PSs with NIR fluorescence and their design strategies, and typical anticancer applications are summarized. Finally, a brief conclusion is obtained, and the underlying challenges and prospects of AIE-active type I PSs are proposed.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Espécies Reativas de Oxigênio , Fluorescência , Oxigênio , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Microambiente Tumoral
3.
J Am Chem Soc ; 145(3): 1607-1616, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36602463

RESUMO

The concept of aggregate science was proposed to explain changes in materials performance that accompany the generation of aggregates, but aggregation-triggered multifunction improvements in a class of materials have rarely been reported. Herein, we present the first report of a new class of multifunctional aggregation-induced emission (AIE) luminogens (AIEgens) based on 5,10-diarylphenazine (DPZ) derivates with full-wavelength emission. Intriguingly, multiple properties, such as fluorescence intensity and free radical and type I reactive oxygen species (ROS) efficiencies, could be simultaneously activated from the unimolecular level to the aggregate state. The mechanisms of this multiple performance improvement are discussed in detail based on sufficient performance characterization, and some of the newly prepared AIEgens exhibited toxicity to cancer cells during photodynamic therapy. This work systematically demonstrates the positive effect of aggregation on improving multiple functions of materials, which is expected to promote the development of aggregate science theory for the design of multifunctional materials.

4.
Journal of Preventive Medicine ; (12): 350-354, 2023.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-971803

RESUMO

Objective@#To evaluate the effect of Triangle hierarchical management among community patients with hypertension, so as to provide insights into the improvements of standardized hypertension management.@*Methods@#Patients with newly diagnosed hypertension from 2 community health service centers in Qiantang District of Hangzhou City by the end of 2020 were randomly assigned to the conventional group and the Triangle group. Patients in the conventional group were given health management services according to the requirements of basic public health service standard for one year, while patients in the Triangle group were given Triangle hierarchical management. The blood pressure, self-management behaviors, treatment compliance, smoking, alcohol consumption and exercise were collected using the self-management behavior scale, treatment compliance scale and self-designed questionnaires, and were compared before and after intervention with analysis of covariance and generalized estimation equations.@*Results@#Totally 200 patients with hypertension were recruited, including 100 patients in the conventional group and 100 patients in the Triangle group. There were no significant differences between the two groups before implementation of interventions in terms of gender, age, educational level or occupation (P>0.05). The reduction in blood pressure, increase in the score of treatment, diet, exercise and living habitat management and the total score of self-management behaviors, increase in the score of adherence to medication regimens, daily living management behaviors, smoking and alcohol consumption preference and the total score of treatment compliance, and increase in the number of patients with normal standard of quitting smoking, quitting alcohol consumption, exercise and blood pressure were significantly higher in the Triangle group than in the conventional group after intervention (P<0.05). @*Conclusions @#Triangle hierarchical management may increase the treatment compliance, improve the self-management behavior and facilitate hypertension control among hypertensive patients, which may be popularized for health management among community patients with hypertension.

5.
Bioresour Technol ; 345: 126538, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34902487

RESUMO

The effects of salinity shock on the anaerobic treatment of fracturing wastewater regarding chemical oxygen demand (COD) removal performance, sludge characteristics and microbial community were investigated. Results showed COD removal efficiency decreased from 76.0% to 69.1%, 65.6%, 33.7% and 21.9% with the increase of salinity from 2.5 g/L to 10, 15, 25 and 45 g/L, respectively. The cumulative biogas production decreased by 13.8%-81.1% when salinity increased to 15-85 g/L. The increase of salinity led to the decline in particle size of granular sludge, and the activity of granular sludge, including SMA, coenzyme F420 and dehydrogenase, was inhibited significantly. Flow cytometry indicated the percentage of damaged cells in granular sludge gradually increased with the increase of salinity. Sequence analysis illustrated that microbial community structure in anaerobic digestion reactor was influenced by the salinity, high salinity reduced the diversity of archaea and decreased the abundance of methanogens, especially Methanosaeta.


Assuntos
Esgotos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Salinidade , Eliminação de Resíduos Líquidos
6.
Bioresour Technol ; 345: 126522, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34896536

RESUMO

Extracellular polymeric substances (EPS) extracted from waste activated sludge were used as endogenous redox mediator to enhance denitrification performance. The nitrate reduction rate increased 1.42-fold when EPS were added at 75 mg C/L (C represents total organic carbon). EPS addition decreased the charge transfer resistance and improved the electron transport system activity. The nitrate reductase and nitrite reductase activities improved by 29.7% and 25.4%, respectively. The activation energy of the system with EPS addition (25.82 kJ/mol) was 31.1% lower than that of the control group (37.49 kJ/mol). Besides, EPS could be used as electron carriers to accelerate electron transport; its primary role was similar to that of the quinone loop in the electron transfer chain. More importantly, EPS addition enhanced carbon source metabolism, which increased the available nicotinamide adenine dinucleotide yield to 1.21 times that of the control group, and thus promoted the denitrification performance of activated sludge.


Assuntos
Desnitrificação , Matriz Extracelular de Substâncias Poliméricas , Carbono , Transporte de Elétrons , Elétrons , Oxirredução , Esgotos
7.
Brain Sci ; 11(7)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34356165

RESUMO

In humans, de novo truncating variants in WASF1 (Wiskott-Aldrich syndrome protein family member 1) have been linked to presentations of moderate-to-profound intellectual disability (ID), autistic features, and epilepsy. Apart from one case series, there is limited information on the phenotypic spectrum and genetic landscape of WASF1-related neurodevelopmental disorder (NDD). In this report, we describe detailed clinical characteristics of six individuals with WASF1-related NDD. We demonstrate a broader spectrum of neurodevelopmental impairment including more mildly affected individuals. Further, we report new variant types, including a copy number variant (CNV), resulting in the partial deletion of WASF1 in monozygotic twins, and three missense variants, two of which alter the same residue, p.W161. This report adds further evidence that de novo variants in WASF1 cause an autosomal dominant NDD.

8.
Am J Hum Genet ; 108(6): 1053-1068, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-33909990

RESUMO

Truncating variants in exons 33 and 34 of the SNF2-related CREBBP activator protein (SRCAP) gene cause the neurodevelopmental disorder (NDD) Floating-Harbor syndrome (FLHS), characterized by short stature, speech delay, and facial dysmorphism. Here, we present a cohort of 33 individuals with clinical features distinct from FLHS and truncating (mostly de novo) SRCAP variants either proximal (n = 28) or distal (n = 5) to the FLHS locus. Detailed clinical characterization of the proximal SRCAP individuals identified shared characteristics: developmental delay with or without intellectual disability, behavioral and psychiatric problems, non-specific facial features, musculoskeletal issues, and hypotonia. Because FLHS is known to be associated with a unique set of DNA methylation (DNAm) changes in blood, a DNAm signature, we investigated whether there was a distinct signature associated with our affected individuals. A machine-learning model, based on the FLHS DNAm signature, negatively classified all our tested subjects. Comparing proximal variants with typically developing controls, we identified a DNAm signature distinct from the FLHS signature. Based on the DNAm and clinical data, we refer to the condition as "non-FLHS SRCAP-related NDD." All five distal variants classified negatively using the FLHS DNAm model while two classified positively using the proximal model. This suggests divergent pathogenicity of these variants, though clinically the distal group presented with NDD, similar to the proximal SRCAP group. In summary, for SRCAP, there is a clear relationship between variant location, DNAm profile, and clinical phenotype. These results highlight the power of combined epigenetic, molecular, and clinical studies to identify and characterize genotype-epigenotype-phenotype correlations.


Assuntos
Anormalidades Múltiplas/patologia , Adenosina Trifosfatases/genética , Anormalidades Craniofaciais/patologia , Metilação de DNA , Epigênese Genética , Transtornos do Crescimento/patologia , Comunicação Interventricular/patologia , Mutação , Transtornos do Neurodesenvolvimento/patologia , Fenótipo , Anormalidades Múltiplas/genética , Estudos de Casos e Controles , Estudos de Coortes , Anormalidades Craniofaciais/genética , Feminino , Predisposição Genética para Doença , Transtornos do Crescimento/genética , Comunicação Interventricular/genética , Humanos , Recém-Nascido , Masculino , Transtornos do Neurodesenvolvimento/genética
9.
Eur J Med Genet ; 63(4): 103817, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31778854

RESUMO

BACKGROUND: DGAT1, a gene encoding a protein involved in lipid metabolism, has been recently implicated in causing a rare nutritional and digestive disease presenting as Congenital Diarrheal Disorder (CDD). Genetic causes of malnutrition can be classified as metabolic disorders, caused by loss of a specific enzyme's function. However, disease driven by genetic variants in lipid metabolism genes is not well understood, and additional information is needed to better understand these effects. METHODS: We gathered a multi-institutional cohort of undiagnosed patients with a constellation of phenotypes presenting as malnutrition and metal ion dysregulation. Clinical Whole Exome Sequencing (WES) was performed on four patients and their unaffected parents. We prioritized genetic variants based on multiple criteria including population allele frequency and presumed inheritance pattern, and identified a candidate gene. Computational modeling was used to investigate if the altered amino acids are likely to result in a dysfunctional enzyme. RESULTS: We identified a multi-institutional cohort of patients presenting with malnutrition-like symptoms and likely pathogenic genomic variants within DGAT1. Multiple approaches were used to profile the effect these variants have on protein structure and function. Laboratory and nutritional intervention studies showed rapid and robust patient responses. CONCLUSIONS: This report adds on to the database for existing mutations known within DGAT1, a gene recently implicated with CDD, and also expands its clinical spectrum. Identification of these DGAT1 mutations by WES has allowed for changes in the patients' nutritional rehabilitation, reversed growth failure and enabled them to be weaned off of total parenteral nutrition (TPN).


Assuntos
Diacilglicerol O-Aciltransferase/genética , Diarreia/genética , Desnutrição/genética , Diarreia/dietoterapia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Desnutrição/dietoterapia , Mutação , Sequenciamento do Exoma
10.
Biomaterials ; 34(12): 2980-90, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23369215

RESUMO

The cell membrane is a critical barrier to effective delivery for many therapeutics, including those which are nanoparticle-based. Improving nanoparticle transport across the cell membrane remains a fundamental challenge. Cancer cells preferentially internalized pegylated calcium phosphate nanoparticles over normal epithelial cells. Furthermore, non-cytotoxic levels of doxorubicin markedly amplified this difference by increasing free unbound caveolin-1 and resulted in enhanced caveolin-mediated nanoparticle endocytosis in cancer cells. Engineered pegylated siRNA-loaded triple-shell calcium phosphate nanoconstructs incorporating ultra-low levels of doxorubicin recapitulated these effects and delivered increased numbers of siRNA into cancer cells with target-specific results. Systemic administration of nanoparticles in vivo demonstrated highly preferential entry into tumors, little bystander organ biodistribution, and significant tumor growth arrest. In conclusion, siRNA-loaded calcium phosphate nanoparticles incorporating non-cytotoxic amounts of doxorubicin markedly enhances nanoparticle internalization and results in increased payload delivery with concomitant on-target effects.


Assuntos
Fosfatos de Cálcio/administração & dosagem , Endocitose , Nanopartículas , Neoplasias/metabolismo , Polietilenoglicóis/química , RNA Interferente Pequeno/química , Sequência de Bases , Linhagem Celular Tumoral , Células Cultivadas , Primers do DNA , Doxorrubicina/administração & dosagem , Humanos , Microscopia Confocal , Microscopia Eletrônica , Neoplasias/patologia , RNA Interferente Pequeno/administração & dosagem , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
11.
Chem Commun (Camb) ; 47(48): 12867-9, 2011 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-22037478

RESUMO

The first example of molecular sieve-promoted TBHP-mediated direct oxidative thiolation of an sp(3) C-H bond adjacent to a nitrogen atom with disulfides under metal-free conditions, which allows for preparation of numerous S,N-containing compounds, is presented. Moreover, diverse benzothiazoles and a fipronil analog can be synthesized through this strategy.

12.
Cancer Biol Ther ; 5(8): 988-92, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16760675

RESUMO

The marine natural product scalaradial (SLD) is a potent inhibitor of secretory phospholipase A(2) (sPLA(2)). Our previous work has demonstrated that SLD inhibits epidermal growth factor receptor-mediated Akt phosphorylation, and this effect is independent of sPLA(2). Here we report the role of SLD in extracellular signal-regulated kinase (ERK)1/2 activation. SLD inhibited ERK1/2 phosphorylation within the first 15 min (early inhibition), then stimulated ERK1/2 phosphorylation after 15 min of SLD treatment (late stimulation) in BEL-7402 cells, displaying biphasic regulatory features. Other PLA(2) inhibitors such as the cytosolic and Ca(2+)-independent PLA(2) inhibitor methyl arachidonyl fluorophosphonate, and another sPLA(2) inhibitor, thioetheramide-phosphatidylcholine, only transiently inhibited ERK1/2 phosphorylation and did not display the stimulatory effect. The early inhibition of ERK1/2 phosphorylation by SLD was reversed by the PLA(2) metabolite arachidonic acid, while the late stimulation was abrogated by constitutively active myristolated-Akt. Furthermore, SLD dose- and time-dependently inhibited the phosphorylation of Raf-1 on Ser 259, which is an established event by which Akt inhibits ERK1/2 activation. Taken together, these data demonstrate a biphasic regulation of ERK1/2 phosphorylation by SLD in a time-dependent manner, i.e., early inhibition and late stimulation. The early inhibition of ERK1/2 phosphorylation is mediated by sPLA(2), at least in part, and the late stimulation is effected through SLD inhibition of Akt. These findings provide further insight into the mechanisms underlying the pharmacological effect of SLD.


Assuntos
Homosteroides/farmacologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfolipases A/antagonistas & inibidores , Terpenos/farmacologia , Ácido Araquidônico/farmacologia , Ácidos Araquidônicos/farmacologia , Western Blotting , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/patologia , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Receptores ErbB/antagonistas & inibidores , Fosfolipases A2 do Grupo II , Humanos , Imunoprecipitação , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/patologia , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Organofosfonatos/farmacologia , Fosfatidilcolinas/farmacologia , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Sesterterpenos , Transdução de Sinais , Células Tumorais Cultivadas
13.
Eur J Cell Biol ; 85(5): 367-74, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16406609

RESUMO

The Ras/Raf/extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathway is known to cross-talk with other signaling pathways, including phosphatidylinositol 3-kinase (PI3K)/Akt pathway. However, the role of PI3K in ERK-1/2 activation induced by tyrosine kinase receptors was not fully understood. Here, we report that two structurally distinct PI3K inhibitors, wortmannin and LY294002, inhibited insulin-induced activation of ERK1/2 but had no effect on EGF-induced activation of ERK1/2 in hepatocellular carcinoma BEL-7402 and SMMC-7721 cells, breast cancer MCF-7 cells, and prostate cancer LNCaP cells. Although protein kinase C could act as a mediator between PI3K and ERK1/2, protein kinase C inhibitor chelerythrine chloride did not inhibit insulin-induced ERK1/2 activation. Both insulin- and EGF-induced ERK1/2 activation are strictly dependent on Ras activation, however, wortmannin only inhibited insulin-induced, but not EGF-induced Ras activation. These results indicate that PI3K plays different roles in the activation of Ras/ERK1/2 signaling by insulin and EGF, and that insulin-stimulated, but not EGF-stimulated, ERK1/2 and Akt signalings diverge at PI3K.


Assuntos
Fator de Crescimento Epidérmico/metabolismo , Insulina/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/fisiologia , Alcaloides/metabolismo , Androstadienos/metabolismo , Benzofenantridinas/metabolismo , Linhagem Celular Tumoral , Cromonas/metabolismo , Ativação Enzimática , Humanos , Morfolinas/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Wortmanina , Proteínas ras/metabolismo
14.
Cancer Biol Ther ; 4(11): 1240-7, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16177565

RESUMO

Cyclic AMP (cAMP), one of the most important intracellular second messengers, has been reported to inhibit proliferation of human hepatocellular carcinoma (HCC) cells via negatively regulating p42/44 mitogen-activated protein kinase. Here, we reported that cAMP inhibited the proliferation of HCC BEL-7402 cells via a novel mechanism. Forskolin, an activator of adenylate cyclase, inhibited fetal bovine serum (FBS)-stimulated BEL-7402 cell proliferation in a dose- and time-dependent manner, along with the inhibition of FBS-stimulated serine/threoine protein kinase Akt (also known as PKB) phosphorylation which is required for Akt activation and this effect was mimicked by 8-Br cAMP. Forskolin also inhibited Akt phosphorylation stimulated by other growth factors such as IGF-1, epidermal growth factor, and insulin. These inhibitions were found not only in BEL-7402 cells, but also in another HCC cell line SMMC-7721 cells. Myr-Akt (myristolated-Akt), a constitutively active Akt which was relatively resistant to cAMP inhibition, conferred BEL-7402 cells resistance to cAMP treatment. However, overexpression of Myr-Akt alone was not sufficient to stimulate BEL-7402 cell proliferation. cAMP inhibited FBS-stimulated Akt phosphorylation in a cAMP-dependent protein kinase-dependent manner. Further studies demonstrated that cAMP inhibited FBS-induced membrane localization of 3-phosphoinositide-dependent kinase 1 (PDK-1) which is a required process for PDK-1 to phosphorylate Akt, but had no significant effect on phosphoinositide 3-kinase activity. These results indicate that cAMP inhibition of proliferation of HCC cells is mediated by Akt and cAMP inhibits Akt activation via blocking membrane localization of PDK-1.


Assuntos
Carcinoma Hepatocelular/metabolismo , Proliferação de Células/efeitos dos fármacos , AMP Cíclico/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Linhagem Celular Tumoral , Colforsina/farmacologia , AMP Cíclico/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Humanos , Cinética , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores
15.
J Pharmacol Exp Ther ; 314(3): 1210-7, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15923342

RESUMO

The marine natural product 12-epi-scalaradial (SLD) is a specific secretory phospholipase A(2) (sPLA(2)) inhibitor. However, little is known about whether this compound has other pharmacological effects. Here, we revealed a novel effect of SLD on epidermal growth factor receptor (EGFR)-mediated Akt phosphorylation. SLD dose- and time-dependently inhibited epidermal growth factor (EGF)-stimulated Akt phosphorylation, which is required for Akt activation. SLD also blocked the EGF-stimulated membrane translocation of 3-phosphoinositide-dependent protein kinase 1 and inhibited phosphatidylinositol 3-kinase activity. This inhibition is specific for SLD because other phospholipase inhibitors, including sPLA(2) inhibitor thioetheramide-phosphatidylcholine, cytosolic PLA(2) inhibitor arachidonyl trifluoromethyl ketone, cytosolic PLA(2) and Ca(2+)-independent PLA(2) inhibitor methyl arachidonyl fluorophosphonate, phospholipase C inhibitor U73122, and cyclooxygenases inhibitor indomethacin, failed to inhibit EGF-stimulated Akt phosphorylation. Furthermore, arachidonic acid, the main sPLA(2)-catalyzed metabolite, was not able to rescue SLD inhibition of EGF-stimulated Akt phosphorylation. Overexpression of group IIA or group X sPLA(2) did not reverse the inhibitory effect of SLD on Akt phosphorylation, either. Our results demonstrate that SLD inhibits EGFR-mediated Akt phosphorylation, and this novel effect of SLD is independent of sPLA(2).


Assuntos
Inibidores Enzimáticos/farmacologia , Receptores ErbB/antagonistas & inibidores , Homosteroides/farmacologia , Fosfolipases A/antagonistas & inibidores , Fosfolipases A/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Terpenos/farmacologia , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Linhagem Celular , Relação Dose-Resposta a Droga , Fosfolipases A2 do Grupo II , Humanos , Inibidores de Fosfoinositídeo-3 Quinase , Fosfolipases A2 , Fosforilação , Proteínas Proto-Oncogênicas c-akt , Sesterterpenos
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