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Reforming tar molecules into smaller gaseous molecules has been a critical challenge for biomass energy utilization. Hematite (α-Fe2O3) has been demonstrated as an effective catalyst for the catalytic reforming of tar, nevertheless, the detailed mechanism of α-Fe2O3 catalyzed tar reforming remains unclear. In this work, we apply the density functional theory method to investigate this problem. Specifically, we study both (0001) and (01[Formula: see text]2) surface structures of α-Fe2O3 and then use the structures to investigate the adsorption and C-C bond cleavage of benzene on these surfaces. Our results show that the dominant interactions between benzene and a single Fe-terminated (0001) surface are van der Waals forces, yet benzene could be chemisorbed on the Fe and O co-exposed (01[Formula: see text]2) surface via strong C-O interactions. As a result, the (0001) surface is not active towards benzene cleavage, whereas the (01[Formula: see text]2) surface can promote the aromatic C-C bond breaking. Furthermore, our calculations indicate that chain-like alkene species and carbonyl species are the two types of potential products that form after the C-C bond cleavage of benzene on the α-Fe2O3 (01[Formula: see text]2) surface, with the activation energy of 1.78 eV and 2.62 eV, respectively. In summary, we reveal the importance of co-adsorption on both Fe and O centers and oxidative addition on C-C bond cleavage of aromatic compounds on the α-Fe2O3 surface, which provides novel insights into the mechanisms of tar cracking on oxide catalysts.
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BACKGROUND: A regimen of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment for non-Hodgkin's lymphoma. Brown adipose tissue possesses anti-cancer potential. This study aimed to explore practical biomarkers for non-Hodgkin's lymphoma by analyzing the metabolic activity of adipose tissue. METHODS: Twenty patients who received R-CHOP for non-Hodgkin's lymphoma were reviewed. Positron emission tomography/computed tomography (PET/CT) images, lactate dehydrogenase (LDH) levels, and body mass index (BMI) before and after treatment were collected. Regions with a high standardized uptake value (SUV) in epicardial and orbital adipose tissue were selected and analyzed by a PET/CT viewer. The initial measurements and changes in the high SUV of epicardial and orbital adipose tissues, LDH levels, and BMI of treatment responders and non-responders, and complete and partial responders, were compared. RESULTS: The volumes of high-SUV epicardial and orbital adipose tissues significantly increased in responders after R-CHOP (p = 0.03 and 0.002, respectively). There were significant differences between changes in the high-SUV volumes of epicardial and orbital adipose tissues (p = 0.03 and 0.001, respectively) and LDH levels (p = 0.03) between responders and non-responders. The changes in high-SUV epicardial adipose tissue volumes were greater among complete responders than partial responders (p = 0.04). Poorer treatment responses were observed in patients with lower high-SUV epicardial adipose tissue volumes and higher LDH levels after R-CHOP (p = 0.03 and 0.03, respectively). CONCLUSIONS: The preliminary results of greater changes in high-SUV epicardial and orbital adipose tissue volumes among responders indicate that brown adipose tissue could be considered a favorable prognostic biomarker.
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Fluordesoxiglucose F18 , Linfoma não Hodgkin , Humanos , Fluordesoxiglucose F18/uso terapêutico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Órbita , Linfoma não Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/tratamento farmacológico , Vincristina/uso terapêutico , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Prednisona/uso terapêutico , Rituximab/uso terapêutico , Pericárdio/diagnóstico por imagem , Tecido Adiposo/diagnóstico por imagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêuticoRESUMO
Iron homeostasis is critical for cellular and organismal function and is tightly regulated to prevent toxicity or anemia due to iron excess or deficiency, respectively. However, subcellular regulatory mechanisms of iron remain largely unexplored. Here, we report that SEL1L-HRD1 protein complex of endoplasmic reticulum (ER)-associated degradation (ERAD) in hepatocytes controls systemic iron homeostasis in a ceruloplasmin (CP)-dependent, and ER stress-independent, manner. Mice with hepatocyte-specific Sel1L deficiency exhibit altered basal iron homeostasis and are sensitized to iron deficiency while resistant to iron overload. Proteomics screening for a factor linking ERAD deficiency to altered iron homeostasis identifies CP, a key ferroxidase involved in systemic iron distribution by catalyzing iron oxidation and efflux from tissues. Indeed, CP is highly unstable and a bona fide substrate of SEL1L-HRD1 ERAD. In the absence of ERAD, CP protein accumulates in the ER and is shunted to refolding, leading to elevated secretion. Providing clinical relevance of these findings, SEL1L-HRD1 ERAD is responsible for the degradation of a subset of disease-causing CP mutants, thereby attenuating their pathogenicity. Together, this study uncovers the role of SEL1L-HRD1 ERAD in systemic iron homeostasis and provides insights into protein misfolding-associated proteotoxicity.
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Ceruloplasmina , Degradação Associada com o Retículo Endoplasmático , Camundongos , Animais , Ceruloplasmina/genética , Ubiquitina-Proteína Ligases/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas/metabolismo , Homeostase , Ferro/metabolismoRESUMO
Background: This study aims to establish and validate a predictive model based on radiomics features, clinical features, and radiation therapy (RT) dosimetric parameters for overall survival (OS) in hepatocellular carcinoma (HCC) patients treated with RT for portal vein tumor thrombosis (PVTT). Methods: We retrospectively reviewed 131 patients. Patients were randomly divided into the training (n = 105) and validation (n = 26) cohorts. The clinical target volume was contoured on pre-RT computed tomography images and 48 textural features were extracted. The least absolute shrinkage and selection operator regression was used to determine the radiomics score (rad-score). A nomogram based on rad-score, clinical features, and dosimetric parameters was developed using the results of multivariate regression analysis. The predictive nomogram was evaluated using Harrell's concordance index (C-index), area under the curve (AUC), and calibration curve. Results: Two radiomics features were extracted to calculate the rad-score for the prediction of OS. The radiomics-based nomogram had better performance than the clinical nomogram for the prediction of OS, with a C-index of 0.73 (95% CI, 0.67-0.79) and an AUC of 0.71 (95% CI, 0.62-0.79). The predictive accuracy was assessed by a calibration curve. Conclusion: The radiomics-based predictive model significantly improved OS prediction in HCC patients treated with RT for PVTT.
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BACKGROUND: Neoadjuvant chemoradiation therapy (NCRT) followed by surgery is the standard treatment for locally advanced rectal cancer (LARC); approximately 80% of patients do not achieve complete response. Identifying prognostic factors predictive of survival in these patients to guide further management is needed. The intratumoural lymphocytic response (ILR), peritumoural lymphocytic reaction (PLR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PtLR) are correlated with the tumour microenvironment and cancer-related systemic inflammation. This study aimed to explore the ability of the ILR, PLR, NLR, and PtLR to predict survival in LARC patients without a complete response to NCRT. METHODS: Sixty-nine patients who underwent NCRT and surgery were retrospectively reviewed. The ILR and PLR were assessed in surgical specimens, and the NLR and PtLR were calculated using pre- and post-NCRT blood count data. The Kaplan-Meier method and Cox regression analyses were performed for survival analysis. RESULTS: A high PLR and high post-NCRT NLR and PtLR were significantly associated with better prognosis. Lymphovascular invasion (LVI), post-NCRT neutrophil count, and lymphocyte count were significant predictors of overall survival. LVI and the PLR were independent predictors of disease-free survival. CONCLUSIONS: NCRT-induced local and systemic immune responses are favourable prognostic predictors in LARC patients without complete response to NCRT.
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Alpha/beta hydrolase domain-containing 5 (ABHD5), also termed CGI-58, is the key upstream activator of adipose triglyceride lipase (ATGL), which plays an essential role in lipid metabolism and energy storage. Mutations in ABHD5 disrupt lipolysis and are known to cause the Chanarin-Dorfman syndrome. Despite its importance, the structure of ABHD5 remains unknown. In this work, we combine computational and experimental methods to build a 3D structure of ABHD5. Multiple comparative and machine learning-based homology modeling methods are used to obtain possible models of ABHD5. The results from Gaussian accelerated molecular dynamics and experimental data of the apo models and their mutants are used to select the most likely model. Moreover, ensemble docking is performed on representative conformations of ABHD5 to reveal the binding mechanism of ABHD5 and a series of synthetic ligands. Our study suggests that the ABHD5 models created by deep learning-based methods are the best candidate structures for the ABHD5 protein. The mutations of E41, R116, and G328 disturb the hydrogen bonding network with nearby residues and suppress membrane targeting or ATGL activation. The simulations also reveal that the hydrophobic interactions are responsible for binding sulfonyl piperazine ligands to ABHD5. Our work provides fundamental insight into the structure of ABHD5 and its ligand-binding mode, which can be further applied to develop ABHD5 as a therapeutic target for metabolic disease and cancer.
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The neutrophil NADPH oxidase produces both intracellular and extracellular reactive oxygen species (ROS). Although oxidase activity is essential for microbial killing, and ROS can act as signaling molecules in the inflammatory process, excessive extracellular ROS directly contributes to inflammatory tissue damage, as well as to cancer progression and immune dysregulation in the tumor microenvironment. How specific signaling pathways contribute to ROS localization is unclear. Here we used a systems pharmacology approach to identify the specific Class I PI3-K isoform p110ß, and PLD1, but not PLD2, as critical regulators of extracellular, but not intracellular ROS production in primary neutrophils. Combined crystallographic and molecular dynamics analysis of the PX domain of the oxidase component p47phox, which binds the lipid products of PI 3-K and PLD, was used to clarify the membrane-binding mechanism and guide the design of mutant mice whose p47phox is unable to bind 3-phosphorylated inositol phospholipids. Neutrophils from these K43A mutant animals were specifically deficient in extracellular, but not intracellular, ROS production, and showed increased dependency on signaling through the remaining PLD1 arm. These findings identify the PX domain of p47phox as a critical integrator of PLD1 and p110ß signaling for extracellular ROS production, and as a potential therapeutic target for modulating tissue damage and extracellular signaling during inflammation.
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Classe I de Fosfatidilinositol 3-Quinases , NADPH Oxidases , Neutrófilos , Espécies Reativas de Oxigênio , Animais , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Ativação Enzimática , Inflamação , Camundongos , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Neutrófilos/enzimologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
BACKGROUND: Incidental radiotherapy (RT) to the adrenal gland may have systemic effects. This study aimed to investigate the effects of adrenal RT on fatigue. METHODS: BALB/c mice were surgically explored to identify the left adrenal gland and delivered intra-operative RT. The swimming endurance test was used for endurance assessment to represent fatigue. Plasma levels of stress hormones and histopathological features were examined. Three patients with inevitable RT to the adrenal gland were enrolled for the preliminary study. Serum levels of cortisol, aldosterone, and adrenocorticotropic hormone (ACTH) were measured before and after RT. Fatigue score by using the fatigue severity scale and RT dosimetric parameters were collected. RESULTS: In the experimental mouse model, adrenal RT decreased baseline cortisol from 274.6 ± 37.8 to 193.6 ± 29.4 ng/mL (p = 0.007) and swimming endurance time from 3.7 ± 0.3 to 1.7 ± 0.6 min (p = 0.02). In histopathological assessment, the irradiated adrenal glands showed RT injury features in the adrenal cortex. In the enrolled patients, baseline cortisol significantly declined after RT. There were no significant differences in the levels of morning cortisol, aldosterone, and ACTH before and after RT. CONCLUSIONS: The RT dose distributed to the adrenal gland may correlate with unwanted adverse effects, including fatigue and adrenal hormone alterations.
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Benzophenone-1 (BP-1), one of the commonly used ultraviolet filters, has caused increasing public concern due to frequently detected residues in environmental and recreational waters. Its susceptibility to residual chlorine and the potential to subsequently trigger endocrine disruption remain unknown. We herein investigated the chlorination of BP-1 in swimming pool water and evaluated the endocrine disruption toward the human androgen receptor (AR). The structures of monochlorinated (P1) and dichlorinated (P2) products were separated and characterized by mass spectrometry and 1H-1H NMR correlation spectroscopy. P1 and P2 exhibited significantly higher antiandrogenic activity in yeast two-hybrid assays (EC50, 6.13 µM and 9.30 µM) than did BP-1 (12.89 µM). Our 350 ns Gaussian accelerated molecular dynamics simulations showed the protein dynamics in a long-time scale equilibrium, and further energy calculations revealed that although increased hydrophobic interactions are primarily responsible for enhanced binding affinities between chlorinated products and the AR ligand binding domain, the second chloride in P2 still hinders the complex motion because of the solvation penalty. The mixture of BP-1-P1-P2 elicited additive antiandrogenic activity, well fitted by the concentration addition model. P1 and P2 at 1 µM consequently downregulated the mRNA expression of AR-regulated genes, NKX3.1 and KLK3, by 1.7-9.1-fold in androgen-activated LNCaP cells. Because chlorination of BP-1 occurs naturally by residual chlorine in aquatic environments, our results regarding enhanced antiandrogenic activity and disturbed AR signaling provided evidence linking the use of personal care products with potential health risks.
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Benzofenonas/farmacologia , Disruptores Endócrinos/farmacologia , Simulação de Dinâmica Molecular , Receptores Androgênicos/metabolismo , Benzofenonas/síntese química , Benzofenonas/química , Sobrevivência Celular/efeitos dos fármacos , Disruptores Endócrinos/síntese química , Disruptores Endócrinos/química , Halogenação , Humanos , Estrutura Molecular , Células Tumorais CultivadasRESUMO
OBJECTIVES: Sarcopenia and systemic inflammation can affect survival of advanced-stage oral squamous cell carcinoma (OSCC) patients; however, their reciprocal associations with survival outcomes are yet to be investigated. STUDY DESIGN: Retrospective review at a tertiary cancer center. METHODS: Patients with stage III-IVB OSCC that underwent surgery and (chemo)radiotherapy at our institution between 2010 and 2015 were reviewed. Skeletal muscle index (SMI) was assessed using computed tomography scans at the C3 vertebra. Sarcopenia was defined at the lowest sex-specific tertile for SMI. Systemic inflammation was estimated using the modified Glasgow prognostic score (mGPS), which ranges from 0 to 2 based on serum C-reactive protein and albumin levels. The predictors of overall survival (OS) were evaluated using Cox regression models. RESULTS: A total of 174 patients were included in the study. The cut-off values for sarcopenia were set at SMI <52.4 cm2 /m2 (men) and < 36.2 cm2 /m2 (women) corresponding to the lowest sex-specific tertile. An mGPS 1-2 was independently associated with sarcopenia (odds ratio: 2.05; 95% confidence interval: 1.06-3.97; P = .03). On multivariate analysis for OS, sarcopenia and mGPS 1-2 independently predicted OS (hazard ratio: 2.12; 95% confidence interval: 1.17-3.85; P = .01 and hazard ratio: 7.85; 95% confidence interval: 3.7-16.65; P < .001, respectively). Patients with both sarcopenia and mGPS 1-2 (vs. neither) had worse OS (hazard ratio: 16.80; 95% confidence interval: 6.01-46.99; P < .001). CONCLUSIONS: Sarcopenia and systemic inflammation may exert a negative synergistic prognostic impact in advanced-stage OSCC patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1530-E1538, 2021.
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Neoplasias Bucais/mortalidade , Recidiva Local de Neoplasia/epidemiologia , Sarcopenia/epidemiologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/mortalidade , Adulto , Proteína C-Reativa/análise , Proteína C-Reativa/imunologia , Quimiorradioterapia Adjuvante , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Inflamação/diagnóstico , Inflamação/epidemiologia , Inflamação/imunologia , Masculino , Pessoa de Meia-Idade , Boca/patologia , Boca/cirurgia , Neoplasias Bucais/complicações , Neoplasias Bucais/imunologia , Neoplasias Bucais/terapia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/imunologia , Recidiva Local de Neoplasia/imunologia , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Medição de Risco/estatística & dados numéricos , Fatores de Risco , Sarcopenia/diagnóstico , Sarcopenia/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/complicações , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/terapia , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVE: Chronic obstructive pulmonary disease (COPD) and benign prostatic hyperplasia (BPH) are common disorders in ageing male populations. Nevertheless, the relationship between the two diseases has rarely been explored. The objective of this study was to examine whether patients with COPD are at an increased risk of BPH. DESIGN: Retrospective nationwide cohort study. SETTING: Data retrieved from the Taiwan National Health Insurance Research Database. PARTICIPANTS: Overall, 19 959 male patients aged 40 years and over with newly diagnosed COPD between 2000 and 2006 were included as the COPD group, and 19 959 sex-matched and age-matched enrollees without COPD were included as the non-COPD group. Both groups were followed-up until the end of 2011. OUTCOME MEASURES: A Cox proportional hazards regression model was used to compute the risk of BPH in patients with COPD compared with enrollees without COPD. RESULTS: The overall incidence rate of BPH was 1.53 times higher in the COPD group than that in the non-COPD group (44.7 vs 25.7 per 1000 person-years, 95% CI 1.46 to 1.60) after adjusting for covariates. An additional stratified analysis revealed that this increased risk of BPH in patients with COPD remained significantly higher than that in enrollees without COPD in all men aged 40 years and over. CONCLUSION: After adjustment for covariates, male patients with COPD were found to be at a higher risk of BPH. We suggest that clinicians should be cautious about the increased risk of BPH in male patients with COPD.
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Hiperplasia Prostática/epidemiologia , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Adulto , Idoso , Bases de Dados Factuais , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Taiwan/epidemiologiaRESUMO
BACKGROUND: Experimental studies showed that 25-hydroxy-vitamin D [25(OH)D] deficiency (defined as 25-hydroxy-vitamin D < 15 ng/ml) has been associated with CKD progression. Patients with IgA nephropathy have an exceptionally high rate of severe 25(OH)D deficiency; however, it is not known whether this deficiency is a risk factor for progression of IgA nephropathy. We conducted this study to investigate the relationship between the plasma level of 25(OH)D and certain clinical parameters and renal histologic lesions in the patients with IgA nephropathy, and to evaluate whether the 25(OH)D level could be a good prognostic marker for IgA nephropathy progression. METHODS: A total of 105 patients with biopsy-proven IgA nephropathy were enrolled between 2012 and 2015. The circulating concentration of 25(OH)D was determined using serum samples collected at the time of biopsy. The primary clinical endpoint was the decline of estimated glomerular filtration rate (eGFR; a 30 % or more decline compared to the baseline). RESULTS: Mean eGFR decreased and proteinuria worsened proportionally as circulating 25(OH)D decreased (P < 0.05). The 25(OH)D deficiency was correlated with a higher tubulointerstitial score by the Oxford classification (P = 0.008). The risk for reaching the primary endpoint was significantly higher in the patients with a 25(OH)D deficiency compared to those with a higher level of 25(OH)D (P = 0.001). As evaluated using the Cox proportional hazards model, 25(OH)D deficiency was found to be an independent risk factor for renal progression [HR 5.99, 95 % confidence intervals (CIs) 1.59-22.54, P = 0.008]. CONCLUSION: A 25(OH)D deficiency at baseline is significantly correlated with poorer clinical outcomes and more sever renal pathological features, and low levels of 25(OH)D at baseline were strongly associated with increased risk of renal progression in IgAN.
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Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/patologia , Deficiência de Vitamina D/sangue , Vitamina D/análogos & derivados , Adulto , Biomarcadores/sangue , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Glomerulonefrite por IGA/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteinúria/etiologia , Fatores de Risco , Vitamina D/sangue , Deficiência de Vitamina D/complicações , Adulto JovemRESUMO
Inhibition of the protein-protein interaction (PPI) mediated by breast-cancer-gene 1 C-terminal (BRCT) is an attractive strategy to sensitize breast and ovarian cancers to chemotherapeutic agents that induce DNA damage. Such inhibitors could also be used for studies to understand the role of this PPI in DNA damage response. However, design of BRCT inhibitors is challenging because of the inherent flexibility associated with this domain. Several studies identified short phosphopeptides as tight BRCT binders. Here we investigated the thermodynamic properties of 18 phosphopeptides or peptide with phosphate mimic and three compounds with phosphate groups binding to BRCT to understand promiscuous molecular recognition and guide inhibitor design. We performed molecular dynamics (MD) simulations to investigate the interactions between inhibitors and BRCT and their dynamic behavior in the free and bound states. MD simulations revealed the key role of loops in altering the shape and size of the binding site to fit various ligands. The mining minima (M2) method was used for calculating binding free energy to explore the driving forces and the fine balance between configuration entropy loss and enthalpy gain. We designed a rigidified ligand, which showed unfavorable experimental binding affinity due to weakened enthalpy. This was because it lacked the ability to rearrange itself upon binding. Investigation of another phosphate group containing compound, C1, suggested that the entropy loss can be reduced by preventing significant narrowing of the energy well and introducing multiple new compound conformations in the bound states. From our computations, we designed an analog of C1 that introduced new intermolecular interactions to strengthen attractions while maintaining small entropic penalty. This study shows that flexible compounds do not always encounter larger entropy penalty, compared with other more rigid binders, and highlights a new strategy for inhibitor design.
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Proteína BRCA1 , Simulação de Dinâmica Molecular , Fosfopeptídeos , Antineoplásicos/análise , Antineoplásicos/química , Antineoplásicos/metabolismo , Proteína BRCA1/antagonistas & inibidores , Proteína BRCA1/química , Proteína BRCA1/metabolismo , Entropia , Humanos , Ligantes , Fosfopeptídeos/análise , Fosfopeptídeos/química , Fosfopeptídeos/metabolismo , Ligação Proteica , TermodinâmicaRESUMO
We recently demonstrated that activation of tyrosine receptor kinase B (TrkB) by 7, 8-dihydroxyflavone (7, 8-DHF), the selective TrkB agonist, increased surface alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors (AMPARs) AMPA receptor subunit GluR1 (GluA1) subunit expression at the synapses of Fragile X Syndrome mutant mice. This present study investigated the effects of 7, 8-DHF on both memory function and synapse structure in relation to the synapse protein level of AMPARs in the Tg2576 Alzheimer's disease (AD) mouse model. The study found that chronic oral administration of 7, 8-DHF significantly improved spatial memory and minimized dendrite loss in the hippocampus of Tg2576 mice. A key feature of 7, 8-DHF action was the increased expression of both GluA1 and GluA2 at synapses. Interestingly, 7, 8-DHF had no effect on the attenuation of amyloid precursor protein or Aß exhibiting in the Tg2576 AD brains, yet it activated the phosphorylation of TrkB receptors and its downstream signals including CaMKII, Akt, Erk1/2, and cAMP-response element-binding protein. Importantly, cyclotraxin B (a TrkB inhibitor), U0126 (a Ras-ERK pathway inhibitor), Wortmannin (an Akt phosphorylation inhibitor), and KN-93 (a CaMKII inhibitor) counteracted the enhanced expression and phosphorylation of AMPAR subunits induced by 7, 8-DHF. Collectively, our results demonstrated that 7, 8-DHF acted on TrkB and resolved learning and memory impairments in the absence of reduced amyloid in amyloid precursor protein transgenic mice partially through improved synaptic structure and enhanced synaptic AMPARs. The findings suggest that the application of 7, 8-DHF may be a promising new approach to improve cognitive abilities in AD. We provided extensive data demonstrating that 7, 8-dihydroflavone, the TrkB agonist, improved Tg2576 mice spatial memory. This improvement is correlated with a reversion to normal values of GluA1 and GluA2 AMPA receptor subunits and dendritic spines in CA1. This work suggests that 7, 8-DHF is a suitable drug to potentiate in vivo Tropomyosin receptor kinase B (TrkB) signaling in the Alzheimer's disease mice model.
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Doença de Alzheimer/complicações , Flavanonas/uso terapêutico , Transtornos da Memória , Receptor trkB/metabolismo , Receptores de AMPA/metabolismo , Sinapses/metabolismo , Doença de Alzheimer/genética , Precursor de Proteína beta-Amiloide/genética , Animais , Modelos Animais de Doenças , Comportamento Exploratório/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Humanos , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sinapses/efeitos dos fármacos , Sinapses/ultraestrutura , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismoRESUMO
The exocyst complex regulates the last steps of exocytosis, which is essential to organisms across kingdoms. In humans, its dysfunction is correlated with several significant diseases, such as diabetes and cancer progression. Investigation of the dynamic regulation of the evolutionarily conserved exocyst-related processes using mutants in genetically tractable organisms such as Arabidopsis thaliana is limited by the lethality or the severity of phenotypes. We discovered that the small molecule Endosidin2 (ES2) binds to the EXO70 (exocyst component of 70 kDa) subunit of the exocyst complex, resulting in inhibition of exocytosis and endosomal recycling in both plant and human cells and enhancement of plant vacuolar trafficking. An EXO70 protein with a C-terminal truncation results in dominant ES2 resistance, uncovering possible distinct regulatory roles for the N terminus of the protein. This study not only provides a valuable tool in studying exocytosis regulation but also offers a potentially new target for drugs aimed at addressing human disease.
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Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Endossomos/metabolismo , Exocitose , Limoninas/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Membrana Celular/metabolismo , Sequência Conservada , Evolução Molecular , Humanos , Estrutura Secundária de ProteínaRESUMO
Signaling in cells often involves co-localization of the signaling molecules. Most experimental evidence has shown that intracellular compartmentalization restricts the range of action of the second messenger, 3'-5'-cyclic adenosine monophosphate (cAMP), which is degraded by phosphodiesterases (PDEs). The objective of this study is to understand the details of molecular encounter that may play a role in efficient operation of the cAMP signaling apparatus. The results from electrostatic potential calculations and Brownian dynamics simulations suggest that positive potential of the active site from PDE enhances capture of diffusing cAMP molecules. This electrostatic steering between cAMP and the active site of a PDE plays a major role in the enzyme-substrate encounter, an effect that may be of significance in sequestering cAMP released from a nearby binding site or in attracting more freely diffusing cAMP molecules.
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AMP Cíclico/química , AMP Cíclico/metabolismo , Diester Fosfórico Hidrolases/química , Diester Fosfórico Hidrolases/metabolismo , Simulação de Dinâmica Molecular , Eletricidade Estática , TermodinâmicaRESUMO
BACKGROUND: The treatment of adhesive capsulitis is a dilemma for orthopaedic rehabilitation specialists. In this study, we assessed whether extracorporeal shockwave therapy (ESWT) improves the functional outcome of primary shoulder adhesive capsulitis. METHODS: In this prospective, randomized, controlled, single-blind clinical trial, we enrolled 40 patients with primary adhesive capsulitis to assess whether ESWT can improve the functional outcome of primary adhesive capsulitis better than oral steroid therapy. Patients were allocated to the oral steroid group or ESWT group with randomization. Functional outcome evaluations were performed using the Constant Shoulder Score (CSS) and Oxford Shoulder Score. RESULTS: Both groups showed significant improvement in the Oxford Shoulder Score evaluation throughout the study period. In the ESWT group, the total CSS and range of motion (ROM) parameter of the CSS in the ESWT group showed significant improvement from the fourth week that was better than that in the steroid group; the activitiesofdaily living (ADL) parameter of the CSS achieved significance and was better than that in the steroid group at the sixth week. For the steroid group, pain was significantly reduced from baseline to the fourth week of the study; ADL and ROM improved at the fourth to 12th week. For the ESWT group, ADL and ROM improvements were significant from baseline to the sixth week. CONCLUSION: Our results showed that ESWT can be an alternative treatment, at least in the short-term, for primary adhesive capsulitis of the shoulder. In addition, all of the side effects of ESWT were transient and tolerable.
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Bursite/terapia , Ondas de Choque de Alta Energia/uso terapêutico , Articulação do Ombro , Administração Oral , Adulto , Bursite/tratamento farmacológico , Feminino , Glucocorticoides/administração & dosagem , Glucocorticoides/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Método Simples-Cego , Terapia por UltrassomRESUMO
Promiscuous proteins are commonly observed in biological systems, for example, in modular domains that recognize phosphopeptides during signal transduction. This promiscuous recognition is of fundamental interest in chemistry and biology but is challenging when designing phosphopeptides in silico for cell biology studies. To investigate promiscuous recognition and binding processes of phosphopeptides and the modular domain, we selected a domain essential in breast cancer-the breast-cancer-associated protein 1 (BRCA1) C-terminal (BRCT) repeats as our model system. We performed molecular dynamics simulations and detailed analyses of the dihedral space to study protein fluctuation and conformational changes with phosphopeptide binding. We also studied the association processes of phosphorylated and unphosphorylated peptides using Brownian dynamics with a coarse-grained model. We found that the BRCT domain is preorganized for phosphopeptide binding but has a moderate arrangement of side chains to form complexes with various types of phosphopeptides. Phosphopeptide binding restricts the system motion in general, while the nonpolar phosphopeptide becomes more flexible in the bound state. Our analysis found that the BRCT domain utilizes different mechanisms, usually termed lock and key, induced-fit, and population-shift/conformational-selection models, to recognize peptides with different features. Brownian dynamics simulations revealed that the charged phosphate group may not always accelerate peptide association processes, but it helps the phosphopeptide orient into binding pockets accurately and stabilizes the complex. This work provides insights into molecular recognition in the promiscuous protein system.
Assuntos
Proteína BRCA1/química , Fosfatos/análise , Fosfopeptídeos/química , Entropia , Humanos , Simulação de Dinâmica MolecularRESUMO
ß1,4-N-acetylgalactosaminyltransferase III (B4GALNT3) promotes the formation of GalNAcß1,4GlcNAc (LacdiNAc or LDN). Drosophila ß1,4-N-acetylgalactosaminyltransferase A (B4GALNTA) contributes to the synthesis of LDN, which helps regulate neuronal development. In this study, we investigated the expression and role of B4GALNT3 in human neuroblastoma (NB). We used IHC analysis to examine 87 NB tumors, and we identified correlations between B4GALNT3 expression and clinicopathologic factors, including patient survival. Effects of recombinant B4GALNT3 on cell behavior and signaling were studied in SK-N-SH and SH-SY5Y NB cells. Increased expression of B4GALNT3 in NB tumors correlated with a favorable histologic profile (P < 0.001, χ² test) and early clinical staging (P = 0.041, χ² test) and was a favorable prognostic factor for survival as evaluated by univariate and multivariate analyses. Reexpression of B4GALNT3 in SK-N-SH and SH-SY5Y cells suppressed cell proliferation, colony formation, migration, and invasion. Moreover, B4GALNT3 increased the LacdiNAc modification of ß1 integrin, leading to decreased phosphorylation of focal adhesion kinase (FAK), Src, paxillin, Akt, and ERK1/2. B4GALNT3-mediated suppression of cell migration and invasion were substantially reversed by concomitant expression of constitutively active Akt or MEK. We conclude that B4GALNT3 predicts a favorable prognosis for NB and suppresses the malignant phenotype via decreasing ß1 integrin signaling.
Assuntos
Biomarcadores Tumorais/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Neuroblastoma/mortalidade , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Sobrevivência Celular , Transformação Celular Neoplásica/metabolismo , Criança , Pré-Escolar , Feminino , Humanos , Integrina beta1 , Masculino , Invasividade Neoplásica/prevenção & controle , Neuroblastoma/metabolismo , Prognóstico , Transdução de Sinais , Tretinoína/farmacologiaRESUMO
Mucins play a key role in tumorigenesis. MUC15 is a membrane-bound mucin and the MUC15 messenger RNA (mRNA) has been detected in various organs. However, its role in tumor malignancy is still unclear. This study was to investigate the MUC15 expression in colorectal tumors and the role of MUC15 in colon cancer cells. We found that the mRNA expression of MUC15 was significantly higher in 70.8% (51/72) of colorectal tumors compared with their normal counterparts by real-time reverse transcription-polymerase chain reaction. Immunohistochemistry showed that MUC15 expression was increased in 82.6% (43/52) of colorectal tumors. MUC15 overexpression in HCT116 cells enhanced cell proliferation, cell-extracellular matrix adhesion, colony-forming ability and invasion. Furthermore, these effects were significantly reversed by knockdown of MUC15 with short-hairpin RNA. In nude mice models, MUC15 overexpression significantly (P < 0.01) enhanced tumor growth. In addition, treatment of PD98059 significantly (P < 0.01) inhibited MUC15-enhanced invasion, suggesting that the invasion induced by MUC15 in HCT116 cells was primarily mediated through activation of extracellular signal-regulated kinase 1/2. In conclusion, these results suggest that MUC15 is upregulated in colorectal tumors and its expression enhances the oncogenic potential of colon cancer cells.