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1.
Nutr Cancer ; 76(7): 608-618, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38753560

RESUMO

Lipids participate in many important biological functions through energy storage, membrane structure stabilization, signal transduction, and molecular recognition. Previous studies have shown that patients with esophageal squamous cell carcinoma (ESCC) have abnormal lipid metabolism. However, studies characterizing lipid metabolism in ESCC patients through lipidomics are limited. Plasma lipid profiles of 65 ESCC patients and 42 healthy controls (HC) were characterized by lipidomics-based ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Single-factor and multi-factor statistical analysis were used to screen the differences in blood lipids between groups, and combined with component ratio analysis and receiver operating characteristic (ROC) curve diagnostic efficiency assessment, to reveal the potential mechanisms and biomarkers of ESCC. There were significant differences in lipid profiles between the ESCC and HC groups. Thirty-six differential lipids (11 up-regulated and 25 down-regulated) were selected based on the criteria of p < .05 and fold change > 1.3 or < 0.77. Glycerophospholipids were the major differential lipids, suggesting that these lipid metabolic pathways exhibit a significant imbalance that may contribute to the development of esophageal squamous cell carcinoma. Among them, the seven candidate biomarkers for esophageal squamous cell carcinoma with the highest diagnostic value are three phosphatidylserine (PS), three fatty acids (FA) and one phosphatidylcholine (PC).


Assuntos
Biomarcadores Tumorais , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Lipidômica , Humanos , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/sangue , Masculino , Neoplasias Esofágicas/sangue , Neoplasias Esofágicas/metabolismo , Lipidômica/métodos , Feminino , Pessoa de Meia-Idade , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/sangue , Estudos de Casos e Controles , Idoso , Metabolismo dos Lipídeos , Lipídeos/sangue , Curva ROC , Glicerofosfolipídeos/sangue , Fosfatidilserinas/metabolismo , Fosfatidilserinas/sangue , Ácidos Graxos/sangue
2.
BMC Public Health ; 24(1): 1624, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890653

RESUMO

BACKGROUND: The relationship between blood lipids and cognitive function has long been a subject of interest, and the association between serum non-high-density lipoprotein cholesterol (non-HDL-C) levels and cognitive impairment remains contentious. METHODS: We utilized data from the 2011 CHARLS national baseline survey, which after screening, included a final sample of 10,982 participants. Cognitive function was assessed using tests of episodic memory and cognitive intactness. We used multiple logistic regression models to estimate the relationship between non-HDL-C and cognitive impairment. Subsequently, utilizing regression analysis results from fully adjusted models, we explored the nonlinear relationship between non-HDL-C as well as cognitive impairment using smooth curve fitting and sought potential inflection points through saturation threshold effect analysis. RESULTS: The results showed that each unit increase in non-HDL-C levels was associated with a 5.5% reduction in the odds of cognitive impairment (OR = 0.945, 95% CI: 0.897-0.996; p < 0.05). When non-HDL-C was used as a categorical variable, the results showed that or each unit increase in non-HDL-C levels, the odds of cognitive impairment were reduced by 14.2%, 20.9%, and 24% in the Q2, Q3, and Q4 groups, respectively, compared with Q1. In addition, in the fully adjusted model, analysis of the potential nonlinear relationship by smoothed curve fitting and saturation threshold effects revealed a U-shaped relationship between non-HDL-C and the risk of cognitive impairment, with an inflection point of 4.83. Before the inflection point, each unit increase in non-HDL-C levels was associated with a 12.3% decrease in the odds of cognitive impairment. After the tipping point, each unit increase in non-HDL-C levels was associated with an 18.8% increase in the odds of cognitive impairment (All p < 0.05). CONCLUSION: There exists a U-shaped relationship between non-HDL-C and the risk of cognitive impairment in Chinese middle-aged and elderly individuals, with statistical significance on both sides of the turning points. This suggests that both lower and higher levels of serum non-high-density lipoprotein cholesterol increase the risk of cognitive impairment in middle-aged and elderly individuals.


Assuntos
Disfunção Cognitiva , Humanos , Estudos Transversais , Feminino , Masculino , Disfunção Cognitiva/sangue , Disfunção Cognitiva/epidemiologia , China/epidemiologia , Pessoa de Meia-Idade , Idoso , Colesterol/sangue , Fatores de Risco , HDL-Colesterol/sangue , População do Leste Asiático
3.
Langmuir ; 39(31): 11073-11080, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37499145

RESUMO

Slippery surfaces with outstanding slippery performances have shown application prospects in various fields, including anti-icing, antifouling, droplet transportation, and fog collection. However, practical application of the existing slippery surfaces is limited by lubricating oil loss, low water-slippery ability, low surface robustness, complex processes, and high costs. To overcome these limitations, we propose a facile, low-cost method to create a solid-like slippery Al surface (SSS-Al) by mixing hydrophobic nano-ceramic coating, silicone oil, and nano-SiO2, which shows excellent comprehensive performance. The SSS-Al shows exceptional water-slippery ability with a sliding angle of 5° and antifouling ability. Durability and chemical stability tests confirm the high surface durability and chemical stability of SSS-Al. Furthermore, SSS-Al exhibits anti-icing performance, fog collection ability, and electrochemical corrosion resistance, as well as demonstrates remarkable application prospects in important fields such as aerospace and shipbuilding.

4.
Environ Microbiol ; 24(12): 6267-6278, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36250814

RESUMO

Ferroptosis is a newly discovered form of cell death accompanied by iron accumulation and lipid peroxidation. Both biotic and abiotic stresses can induce ferroptosis in plant cells. In the case of plant interactions with pathogenic Phytophthora oomycetes, the roles of ferroptosis are still largely unknown. Here, we performed transcriptome analysis on soybean plants treated with the biocontrol agent Pythium oligandrum, a soilborne and non-pathogenic oomycete capable of inducing plant resistance against Phytophthora sojae infection. Expression of homologous soybean genes involved in ferroptosis and resistance was reprogrammed upon P. oligandrum treatment. Typical hallmarks for characterizing ferroptosis were detected in soybean hypocotyl cells, including decreased glutathione (GSH) level, accumulation of ferric ions, and lipid peroxidation by reactive oxygen species (ROS). Meanwhile, ferroptosis-like cell death was triggered by P. oligandrum to suppress P. sojae infection in soybean. Protection provided by P. oligandrum could be attenuated by the ferroptosis inhibitor ferrostatin-1 (Fer-1), suggesting the critical role of ferroptosis in soybean resistance against P. sojae. Taken together, these results demonstrate that ferroptosis is a P. oligandrum-inducible defence mechanism against oomycete infection in soybean.


Assuntos
Ferroptose , Phytophthora , Pythium , Glycine max/genética , Doenças das Plantas/prevenção & controle , Doenças das Plantas/genética , Resistência à Doença/genética
5.
Fungal Genet Biol ; 161: 103695, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35513256

RESUMO

Being found in all eukaryotes investigated, acyl-CoA-binding proteins (ACBPs) participate in lipid metabolism via specifically binding acyl-CoA esters with high affinity. The structures and functions of ACBP family proteins have been extensively described in yeasts, fungi, plants and mammals, but not oomycetes. In the present study, seven ACBP genes named PsACBP1-7 were identified from the genome of Phytophthora sojae, an oomycete pathogen of soybean. CRISPR-Cas9 knockout mutants targeting PsACBP1 and PsACBP2 were created for phenotypic assays. PsACBP1 knockout led to defects in sporangia production and virulence. PsACBP2 knockout mutants exhibited impaired vegetative growth, zoospore production, cyst germination and virulence. Moreover, Nile red staining of PsACBP2 knockout and over-expression lines showed that PsACBP2 is involved in the formation of lipid bodies in P. sojae. Our results demonstrate that two ACBP genes are differently required for growth and development, and both are essential for virulence in P. sojae.


Assuntos
Phytophthora , Animais , Coenzima A/metabolismo , Inibidor da Ligação a Diazepam/genética , Inibidor da Ligação a Diazepam/metabolismo , Mamíferos/metabolismo , Glycine max/genética , Virulência/genética
6.
Am J Pathol ; 190(9): 1888-1908, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32553806

RESUMO

Myopia is a leading cause of visual impairment worldwide. This sight-compromising condition is associated with scleral thinning, extracellular matrix remodeling, and inappropriate optical axial length elongation. Although macrophages are present in the sclera, their involvement in this condition is unknown. By using a form-deprivation myopia (FDM) mouse model, we found that both the scleral macrophage density and their matrix metalloproteinase-2 (MMP-2) expression levels increased in myopic eyes. Partial scleral macrophage depletion by clodronate shifted the refraction toward hyperopia in both the form-deprived and the untreated fellow eyes compared with their respective counterparts in the vehicle-injected control mice. However, this procedure did not alter susceptibility to FDM. FDM development was 59% less in the macrophage-specific Mmp2 deletion (LysMCreMmp-2fl/fl) mice than in their Cre-negative littermates (Mmp2fl/fl mice). Moreover, the expression of scleral C-C motif chemokine ligand-2 (CCL2), which is a potent monocyte chemoattractant recruiting monocytes to tissue sites, was increased during myopia progression. However, the increase in the density of scleral macrophages and myopia development were suppressed in fibroblast-specific Ccl2 deletion mice. These declines suggested that the increase in scleral macrophage density in myopic eyes stems from the up-regulation of scleral Ccl2 expression in fibroblasts, which, in turn, promotes monocytes recruitment. In summary, scleral monocyte-derived macrophages contribute to myopia development through enhancing MMP-2 expression in mice.


Assuntos
Macrófagos/enzimologia , Metaloproteinase 2 da Matriz/metabolismo , Miopia/enzimologia , Esclera/enzimologia , Esclera/patologia , Animais , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Miopia/patologia , Regulação para Cima
7.
J Neurochem ; 155(1): 62-80, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32491248

RESUMO

Alzheimer's disease (AD) is the leading type of dementia worldwide. With an increasing burden of an aging population coupled with the lack of any foreseeable cure, AD warrants the current intense research effort on the toxic effects of an increased concentration of beta-amyloid (Aß) in the brain. Glutamate is the main excitatory brain neurotransmitter and it plays an essential role in the function and health of neurons and neuronal excitability. While previous studies have shown alterations in expression of glutamatergic signaling components in AD, the underlying mechanisms of these changes are not well understood. This is the first comprehensive anatomical study to characterize the subregion- and cell layer-specific long-term effect of Aß1-42 on the expression of specific glutamate receptors and transporters in the mouse hippocampus, using immunohistochemistry with confocal microscopy. Outcomes are examined 30 days after Aß1-42 stereotactic injection in aged male C57BL/6 mice. We report significant decreases in density of the glutamate receptor subunit GluA1 and the vesicular glutamate transporter (VGluT) 1 in the conus ammonis 1 region of the hippocampus in the Aß1-42 injected mice compared with artificial cerebrospinal fluid injected and naïve controls, notably in the stratum oriens and stratum radiatum. GluA1 subunit density also decreased within the dentate gyrus dorsal stratum moleculare in Aß1-42 injected mice compared with artificial cerebrospinal fluid injected controls. These changes are consistent with findings previously reported in the human AD hippocampus. By contrast, glutamate receptor subunits GluA2, GluN1, GluN2A, and VGluT2 showed no changes in expression. These findings indicate that Aß1-42 induces brain region and layer specific expression changes of the glutamatergic receptors and transporters, suggesting complex and spatial vulnerability of this pathway during development of AD neuropathology. Read the Editorial Highlight for this article on page 7. Cover Image for this issue: https://doi.org/10.1111/jnc.14763.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Hipocampo/metabolismo , Fragmentos de Peptídeos/toxicidade , Receptores de AMPA/biossíntese , Proteína Vesicular 1 de Transporte de Glutamato/biossíntese , Peptídeos beta-Amiloides/farmacologia , Animais , Região CA1 Hipocampal/efeitos dos fármacos , Região CA1 Hipocampal/metabolismo , Região CA3 Hipocampal/efeitos dos fármacos , Região CA3 Hipocampal/metabolismo , Giro Denteado/efeitos dos fármacos , Giro Denteado/metabolismo , Hipocampo/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/farmacologia , Receptores de AMPA/genética , Proteína Vesicular 1 de Transporte de Glutamato/genética
8.
Planta ; 252(4): 48, 2020 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-32892254

RESUMO

MAIN CONCLUSION: The NAC transcription factor ATAF2 suppresses its own transcription via self-promoter binding. ATAF2 genetically interacts with the circadian regulator CCA1 and phytochrome A to modulate seedling photomorphogenesis in Arabidopsis thaliana. ATAF2 (ANAC081) is a NAC (NAM, ATAF and CUC) transcription factor (TF) that participates in the regulation of disease resistance, stress tolerance and hormone metabolism in Arabidopsis thaliana. We previously reported that ATAF2 promotes Arabidopsis hypocotyl growth in a light-dependent manner via transcriptionally suppressing the brassinosteroid (BR)-inactivating cytochrome P450 genes BAS1 (CYP734A1, formerly CYP72B1) and SOB7 (CYP72C1). Assays using low light intensities suggest that the photoreceptor phytochrome A (PHYA) may play a more critical role in ATAF2-regulated photomorphogenesis than phytochrome B (PHYB) and cryptochrome 1 (CRY1). In addition, ATAF2 is also regulated by the circadian clock. The core circadian TF CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) physically interacts with ATAF2 at the DNA-protein and protein-protein levels, and both differentially suppress BAS1- and SOB7-mediated BR catabolism. In this research, we show that ATAF2 can bind its own promoter as a transcriptional self-repressor. This self-feedback-suppression loop is a typical feature of multiple circadian-regulated genes. Additionally, ATAF2 and CCA1 synergistically suppress seedling photomorphogenesis as reflected by the light-dependent hypocotyl growth analysis of their single and double gene knock-out mutants. Similar fluence-rate response assays using ATAF2 and photoreceptor (PHYB, CRY1 and PHYA) knock-out mutants demonstrate that PHYA is required for ATAF2-regulated photomorphogenesis in a wide range of light intensities. Furthermore, disruption of PHYA can suppress the BR-insensitive hypocotyl-growth phenotype of ATAF2 loss-of-function seedlings in the light, but not in darkness. Collectively, our results provide a genetic interaction synopsis of the circadian-clock-photomorphogenesis-BR integration node involving ATAF2, CCA1 and PHYA.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Fitocromo A , Desenvolvimento Vegetal , Proteínas Repressoras , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Mutação , Fitocromo A/metabolismo , Fitocromo B/genética , Desenvolvimento Vegetal/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Plântula/genética
9.
Natl Med J India ; 33(1): 15-18, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33565480

RESUMO

Background: From June 2013 to June 2018, patients suffering from Asian giant hornet stings were treated with renal replacement therapy (RRT) in our hospital. We analysed the efficacy of different modalities of RRT in these patients. Methods: A comprehensive clinical history was recorded and a complete physical examination was done for each patient. Three different treatment plans were used in these patients according to the acute physiology and chronic health evaluation (APACHE) II score. These were: (i) haemoperfusion (HP) and intermittent haemodialysis (IHD); (ii) HP and continuous veno-venous haemofiltration (CVVH); and (iii) HP, CVVH and plasma exchange (PE). Results: The average time of RRT was shorter in HP and CVVH or HP, CVVH and PE groups than in the HP and IHD group, and the patients who received HP and CVVH or HP, CVVH and PE had lower levels of blood urea nitrogen and serum creatinine after RRT for 7 days. Conclusion: Our study suggests that HP and CVVH or HP, CVVH and PE are effective treatments for patients suffering from Asian giant hornet stings, who require RRT.


Assuntos
Mordeduras e Picadas , Hemofiltração , Vespas , Animais , Humanos , Terapia de Substituição Renal , Estudos Retrospectivos
10.
New Phytol ; 222(3): 1561-1572, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30623449

RESUMO

Fungal plant pathogens, like rust-causing biotrophic fungi, secrete hundreds of effectors into plant cells to subvert host immunity and promote pathogenicity on their host plants by manipulating specific physiological processes or signal pathways, but the actual function has been demonstrated for very few of these proteins. Here, we show that the PgtSR1 effector proteins, encoded by two allelic genes (PgtSR1-a and PgtSR1-b), from the wheat stem rust pathogen Puccinia graminis f. sp. tritici (Pgt), suppress RNA silencing in plants and impede plant defenses by altering the abundance of small RNAs that serve as defense regulators. Expression of the PgtSR1s in plants revealed that the PgtSR1s promote susceptibility to multiple pathogens and partially suppress cell death triggered by multiple R proteins. Overall, our study provides the first evidence that the filamentous fungus P. graminis has evolved to produce fungal suppressors of RNA silencing and indicates that PgtSR1s suppress both basal defenses and effector triggered immunity.


Assuntos
Basidiomycota/metabolismo , Proteínas Fúngicas/metabolismo , Plantas/imunologia , Plantas/microbiologia , Interferência de RNA , Alelos , Arabidopsis/microbiologia , Basidiomycota/genética , Morte Celular , Regulação Fúngica da Expressão Gênica , Proteínas de Fluorescência Verde/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Plantas Geneticamente Modificadas , RNA de Plantas/metabolismo , Nicotiana/microbiologia , Transgenes
11.
Proc Natl Acad Sci U S A ; 113(33): 9333-8, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27482104

RESUMO

High-risk human papillomaviruses (HPVs) are causative agents of anogenital cancers and a fraction of head and neck cancers. The mechanisms involved in the progression of HPV neoplasias to cancers remain largely unknown. Here, we report that O-linked GlcNAcylation (O-GlcNAc) and O-GlcNAc transferase (OGT) were markedly increased in HPV-caused cervical neoplasms relative to normal cervix, whereas O-GlcNAcase (OGA) levels were not altered. Transduction of HPV16 oncogene E6 or E6/E7 into mouse embryonic fibroblasts (MEFs) up-regulated OGT mRNA and protein, elevated the level of O-GlcNAc, and promoted cell proliferation while reducing cellular senescence. Conversely, in HPV-18-transformed HeLa cervical carcinoma cells, inhibition of O-GlcNAc with a low concentration of a chemical inhibitor impaired the transformed phenotypes in vitro. We showed that E6 elevated c-MYC via increased protein stability attributable to O-GlcNAcylation on Thr58. Reduction of HPV-mediated cell viability by a high concentration of O-GlcNAc inhibitor was partially rescued by elevated c-MYC. Finally, knockdown of OGT or O-GlcNAc inhibition in HeLa cells or in TC-1 cells, a mouse cell line transformed by HPV16 E6/E7 and activated K-RAS, reduced c-MYC and suppressed tumorigenesis and metastasis. Thus, we have uncovered a mechanism for HPV oncoprotein-mediated transformation. These findings may eventually aid in the development of effective therapeutics for HPV-associated malignancies by targeting aberrant O-GlcNAc.


Assuntos
Carcinogênese , N-Acetilglucosaminiltransferases/fisiologia , Proteínas Oncogênicas Virais/fisiologia , Proteínas Repressoras/fisiologia , Neoplasias do Colo do Útero/etiologia , Animais , Linhagem Celular Tumoral , Feminino , Genes myc , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas E7 de Papillomavirus/fisiologia , Neoplasias do Colo do Útero/virologia
12.
Molecules ; 24(11)2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31174300

RESUMO

In this study, two phenol compounds, magnolol and honokiol, were extracted from Magnolia officinalis and identified by LC-MS, 1H- and 13C-NMR. The magnolol and honokiol were shown to be effective against seven pathogenic fungi, including Alternaria alternata (Fr.) Keissl, Penicillium expansum (Link) Thom, Alternaria dauci f.sp. solani, Fusarium moniliforme J. Sheld, Fusarium oxysporum Schltdl., Valsa mali Miyabe & G. Yamada, and Rhizoctonia solani J.G. Kühn, with growth inhibition of more than 57%. We also investigated the mechanisms underlying the potential antifungal activity of magnolol and honokiol. The results showed that they inhibited the growth of A. alternata in a dose-dependent manner. Moreover, magnolol and honokiol treatment resulted in distorted mycelia and increased the cell membrane permeability of A. alternata, as determined by conductivity measurements. These results suggest that magnolol and honokiol are potential antifungal agents for application against plant fungal diseases.


Assuntos
Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Lignanas/química , Lignanas/farmacologia , Magnolia/efeitos dos fármacos , Doenças das Plantas/microbiologia , Alternaria/efeitos dos fármacos , Alternaria/patogenicidade , Antifúngicos/química , Antifúngicos/farmacologia , Magnolia/química , Nicotiana/efeitos dos fármacos , Nicotiana/microbiologia
13.
Bioorg Med Chem Lett ; 28(10): 1954-1957, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29653894

RESUMO

HCV NS5A inhibitors have shown impressive in vitro potency profiles in HCV replicon assays thus making them attractive components for inclusion in an all oral fixed dose combination regimen. Herein, we describe the discovery and characterization of silyl proline-containing HCV NS5A inhibitor MK-8325 with good pan-genotype activity and acceptable pharmacokinetic properties.


Assuntos
Antivirais/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Prolina/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Cães , Genótipo , Meia-Vida , Haplorrinos , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Hepacivirus/fisiologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacocinética , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Humanos , Ratos , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
14.
J Transl Med ; 15(1): 189, 2017 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-28877725

RESUMO

BACKGROUND: In order to improve therapy for head and neck squamous cell carcinoma (HNSCC), biomarkers associated with local and/or distant tumor relapses and cancer drug resistance are urgently needed. This study identified a potential biomarker, Bcl-2 associated athanogene-1 (BAG-1), that is implicated in HNSCC insensitive to cisplatin and tumor progression. METHODS: Primary and advanced (relapsed from parental) University of Michigan squamous cell carcinoma cell lines were tested for sensitivity to cisplatin and gene expression profiles were compared between primary (cisplatin sensitive) and the relapsed (cisplatin resistant) cell lines by using Agilent microarrays. Additionally, differentially expressed genes phosphorylated AKT, and BAG-1, and BCL-xL were evaluated for expression using HNSCC tissue arrays. RESULTS: Advanced HNSCC cells revealed resistant to cisplatin accompanied by increased expression of BAG-1 protein. siRNA knockdown of BAG-1 expression resulted in significant improvement of HNSCC sensitivity to cisplatin. BAG-1 expression enhanced stability of BCL-xL and conferred cisplatin resistant to the HNSCC cells. In addition, high levels of expression of phosphorylated AKT, BAG-1, and BCL-xL were observed in advanced HNSCC compared to in that of primary HNSCC. CONCLUSION: Increased expression of BAG-1 was associated with cisplatin resistance and tumor progression in HNSCC patients and warrants further validation in larger independent studies. Over expression of BAG-1 may be a biomarker for cisplatin resistance in patients with primary or recurrent HNSCCs and targeting BAG-1 could be helpful in overcoming cisplatin resistance.


Assuntos
Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Cisplatino/uso terapêutico , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Fatores de Transcrição/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Cisplatino/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Reprodutibilidade dos Testes , Transdução de Sinais/efeitos dos fármacos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
15.
Biochem Biophys Res Commun ; 473(1): 329-335, 2016 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-27018252

RESUMO

Dithiolopyrrolone group antibiotics characterized by an electronically unique dithiolopyrrolone heterobicyclic core are known for their antibacterial, antifungal, insecticidal and antitumor activities. Recently the biosynthetic gene clusters for two dithiolopyrrolone compounds, holomycin and thiomarinol, have been identified respectively in different bacterial species. Here, we report a novel dithiolopyrrolone biosynthetic gene cluster (aut) isolated from Streptomyces thioluteus DSM 40027 which produces two pyrrothine derivatives, aureothricin and thiolutin. By comparison with other characterized dithiolopyrrolone clusters, eight genes in the aut cluster were verified to be responsible for the assembly of dithiolopyrrolone core. The aut cluster was further confirmed by heterologous expression and in-frame gene deletion experiments. Intriguingly, we found that the heterogenetic thioesterase HlmK derived from the holomycin (hlm) gene cluster in Streptomyces clavuligerus significantly improved heterologous biosynthesis of dithiolopyrrolones in Streptomyces albus through coexpression with the aut cluster. In the previous studies, HlmK was considered invalid because it has a Ser to Gly point mutation within the canonical Ser-His-Asp catalytic triad of thioesterases. However, gene inactivation and complementation experiments in our study unequivocally demonstrated that HlmK is an active distinctive type II thioesterase that plays a beneficial role in dithiolopyrrolone biosynthesis.


Assuntos
Proteínas de Bactérias/biossíntese , Esterases/metabolismo , Pirróis/química , Streptomyces/enzimologia , Compostos de Sulfidrila/química , Tioléster Hidrolases/biossíntese , Antibacterianos/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Domínio Catalítico , Clonagem Molecular , Biologia Computacional , Esterases/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Filogenia , Streptomyces/genética , Tioléster Hidrolases/química
16.
Bioorg Med Chem Lett ; 26(20): 5132-5137, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27634194

RESUMO

Herein, we describe our research efforts to develop unique cores in molecules which function as HCV nonstructural protein 5A (NS5A) inhibitors. In particular, various fused tetracyclic cores were identified which showed genotype and mutant activities comparable to the indole-based tetracyclic core.


Assuntos
Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos
17.
Bioorg Med Chem Lett ; 26(15): 3414-20, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27394665

RESUMO

Herein we describe our research efforts around the aryl and heteroaryl substitutions at the aminal carbon of the tetracyclic indole-based HCV NS5A inhibitor MK-8742. A series of potent NS5A inhibitors are described, such as compounds 45-47, 54, 56, and 65, which showed improved potency against clinically relevant and resistance associated HCV variants. The improved potency profiles of these compounds demonstrated an SAR that can improve the potency against GT2b, GT1a Y93H, and GT1a L31V altogether, which was unprecedented in our previous efforts in NS5A inhibition.


Assuntos
Antivirais/farmacologia , Benzofuranos/farmacologia , Hepacivirus/efeitos dos fármacos , Imidazóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Antivirais/síntese química , Antivirais/química , Benzofuranos/síntese química , Benzofuranos/química , Relação Dose-Resposta a Droga , Imidazóis/síntese química , Imidazóis/química , Masculino , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade
19.
Bioorg Med Chem Lett ; 26(19): 4851-4856, 2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27568086

RESUMO

As part of an ongoing effort in NS5A inhibition at Merck we now describe our efforts for introducing substitution around the tetracyclic indole core of MK-8742. Fluoro substitution on the core combined with the fluoro substitutions on the proline ring improved the potency against GT1a Y93H significantly. However, no improvement on GT2b potency was achieved. Limiting the fluoro substitution to C-1 of the tetracyclic indole core had a positive impact on the potency against the resistance associated variants, such as GT1a Y93H and GT2b, and the PK profile as well. Compounds, such as 62, with reduced potency shifts between wild type GT1a to GT2b, GT1a Y93H, and GT1a L31V were identified.


Assuntos
Antivirais/farmacologia , Benzofuranos/farmacologia , Imidazóis/farmacologia , Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/química , Antivirais/farmacocinética , Benzofuranos/química , Benzofuranos/farmacocinética , Imidazóis/química , Imidazóis/farmacocinética , Indóis/química , Indóis/farmacocinética , Relação Estrutura-Atividade
20.
Bioorg Med Chem Lett ; 26(13): 3158-3162, 2016 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-27180013

RESUMO

HCV NS5A inhibitors have demonstrated impressive in vitro potency profiles in HCV replicon assays and robust HCV RNA titer reduction in the clinic making them attractive components for inclusion in an all oral fixed dose combination regimen for the treatment of HCV infection. Herein, we describe research efforts that led to the discovery of a series of fused tricyclic core containing HCV NS5A inhibitors such as 24, 39, 40, 43, and 44 which have pan-genotype activity and are orally bioavailable in the rat.


Assuntos
Antivirais/farmacologia , Descoberta de Drogas , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/síntese química , Antivirais/química , Relação Dose-Resposta a Droga , Genótipo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/genética , Replicação Viral/efeitos dos fármacos
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