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1.
BMC Geriatr ; 24(1): 473, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816804

RESUMO

BACKGROUND: Circulating miRNAs (c-miR) have been shown to be potential biomarkers in sarcopenia, but the miRNAs response to aerobic exercise in older people remains inconclusive. We sought to examine the exercise benefits on physical fitness and miRNAs, and to explore the mediating effect of miRNAs on training-induced fitness changes. METHODS: This controlled trial recruited 58 community-dwelling older adults and randomized them into exercise group (EX) and control group (CON). EX received 8-week supervised moderate intensity cycling training 3x/week. C-miR expression (c-miR-21, c-miR-126, c-miR-146a, c-miR-222), physical fitness (body composition, cardiorespiratory fitness, muscular fitness) and physical activity level (PAL, measured as in daily step counts) were evaluated at baseline, post-training, and post-16-week follow-up. The mediating effect of miRNA expression onto exercise-induced physical fitness change was determined by causal mediation analysis (CMA). RESULTS: Exercise significantly improved body fat and cardiorespiratory fitness in older people while maintaining muscle mass and strength, and augmented expression of c-miR-126, c-miR-146a, and c-miR-222 for up to 16 weeks post-training. Notably, older people in EX had substantially higher daily step counts than CON throughout the study even after the active training period. However, CMA revealed no significant indirect effect but a potential mediating effect of c-miR-21, but not the rest, onto the body composition, cardiorespiratory fitness, and lower limb strength. CONCLUSION: An eight-week supervised MICT program promoted a higher level of physical activity up to 16 weeks post-training, which induces better cardiorespiratory fitness and resists decline in muscular measures. C-miRNA, especially c-miR-21, potentially mediates the training effect upon fitness.


Assuntos
MicroRNA Circulante , Exercício Físico , Vida Independente , Aptidão Física , Humanos , Idoso , Masculino , Aptidão Física/fisiologia , Feminino , Exercício Físico/fisiologia , Seguimentos , MicroRNA Circulante/sangue , Idoso de 80 Anos ou mais
2.
Eur J Appl Physiol ; 124(3): 837-848, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37712975

RESUMO

PURPOSE: Adrenergic stimulation affects lymphocyte autophagy and apoptosis by activating ß1-adrenergic receptor (ß1-AR) and G protein-coupled receptor kinase 2 (GRK-2) downstream signaling. This study investigated how combined aerobic and resistance exercise training on the interval or continuous pattern influences aerobic/muscular fitness and ß1-AR/GRK-2 signaling, and corresponding apoptosis/autophagy of lymphocytes in sedentary males. METHODS: Thirty-four sedentary males were randomized into interval training (IT, age = 22.5 ± 0.6 years, fitness level = 47.5 ± 0.9 mL/min/kg, body mass index (BMI) = 22.4 ± 0.4 kg/m2, n = 17) and continuous training (CT, age = 21.6 ± 0.4 years, fitness level = 45.2 ± 1.0 mL/min/kg, BMI = 22.2 ± 0.3 kg/m2, n = 17) groups. These subjects performed IT (bicycle exercise at alternating 40% and 80%VO2 reserve (VO2R) and isokinetic exercise at alternating 60°/s and 180°/s) or CT (bicycle exercise at continuously 60%VO2R and isokinetic exercise at continuously 120°/s) for 30 min/day, 5 days/week for 6 weeks. Aerobic capacity and muscular strength/endurance were determined by the graded exercise test (GXT) and isokinetic strength test, respectively. Blood lymphocyte autophagy/apoptosis and ß1-AR/GRK-2 signaling were analyzed using flow cytometry. RESULTS: Both IT and CT groups increased isokinetic strengths at various angular velocities, whereas only IT significantly enhanced muscle endurance, indicated by lowered fatigue index from 47.0 ± 1.3% to 41.8 ± 1.6% (P < 0.05). Moreover, the IT group (143 ± 7%) revealed a higher improvement in VO2peak than CT group (132 ± 6%) (P < 0.05). Acute GXT augmented (i) GRK-2 and protein kinase A expressions, (ii) LAMP-2 upregulation and acridine orange staining, (iii) mitochondrial transmembrane potential diminishing, caspase-3 activation, and phosphatidylserine (PS) exposure caused by epinephrine in blood lymphocytes. However, the degree of epinephrine-induced lymphocyte PS exposure potentiated by GXT was suppressed from 65.2 ± 5.2% to 47.4 ± 6.5% following 6 weeks of the IT (P < 0.05). CONCLUSION: The IT may be considered more beneficial than CT in terms of improving aerobic/muscular fitness and simultaneously ameliorating apoptosis of blood lymphocyte evoked by intense exercise or adrenergic stimulation in sedentary males.


Assuntos
Treinamento Resistido , Masculino , Humanos , Adulto Jovem , Adulto , Adrenérgicos/metabolismo , Linfócitos/metabolismo , Apoptose/fisiologia , Epinefrina
3.
Int J Mol Sci ; 25(4)2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38397048

RESUMO

Negative Pressure Wound Therapy (NPWT) is a commonly employed clinical strategy for wound healing, yet its early-stage mechanisms remain poorly understood. To address this knowledge gap and overcome the limitations of human trials, we establish an NPWT C57BL/6JNarl mouse model to investigate the molecular mechanisms involved in NPWT. In this study, we investigate the intricate molecular mechanisms through which NPWT expedites wound healing. Our focus is on NPWT's modulation of inflammatory immune responses and the concurrent orchestration of multiple signal transduction pathways, resulting in shortened coagulation time and reduced inflammation. Notably, we observe a significant rise in dickkopf-related protein 1 (DKK-1) concentration during NPWT, promoting the differentiation of Hair Follicle Stem Cells (HFSCs) into epidermal cells, expediting wound closure. Under negative pressure, macrophages express and release DKK-1 cytokines, crucial for stimulating HFSC differentiation, as validated in animal experiments and in vitro studies. Our findings illuminate the inflammatory dynamics under NPWT, revealing potential signal transduction pathways. The proposed framework, involving early hemostasis, balanced inflammation, and macrophage-mediated DKK-1 induction, provides a novel perspective on enhancing wound healing during NPWT. Furthermore, these insights lay the groundwork for future pharmacological advancements in managing extensive wounds, opening avenues for targeted therapeutic interventions in wound care.


Assuntos
Tratamento de Ferimentos com Pressão Negativa , Humanos , Camundongos , Animais , Tratamento de Ferimentos com Pressão Negativa/métodos , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Cicatrização , Inflamação/terapia
4.
Hum Brain Mapp ; 44(7): 2669-2683, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36807461

RESUMO

The preprocessing of diffusion magnetic resonance imaging (dMRI) data involve numerous steps, including the corrections for head motion, susceptibility distortion, low signal-to-noise ratio, and signal drifting. Researchers or clinical practitioners often need to configure different preprocessing steps depending on disparate image acquisition schemes, which increases the technical threshold for dMRI analysis for nonexpert users. This could cause disparities in data processing approaches and thus hinder the comparability between studies. To make the dMRI data processing steps transparent and adapt to various dMRI acquisition schemes for researchers, we propose a semi-automated pipeline tool for dMRI named integrated diffusion image operator or iDIO. This pipeline integrates features from a wide range of advanced dMRI software tools and targets at providing a one-click solution for dMRI data analysis, via adaptive configuration for a set of suggested processing steps based on the image header of the input data. Additionally, the pipeline provides options for post-processing, such as estimation of diffusion tensor metrics and whole-brain tractography-based connectomes reconstruction using common brain atlases. The iDIO pipeline also outputs an easy-to-interpret quality control report to facilitate users to assess the data quality. To keep the transparency of data processing, the execution log and all the intermediate images produced in the iDIO's workflow are accessible. The goal of iDIO is to reduce the barriers for clinical or nonspecialist users to adopt the state-of-art dMRI processing steps.


Assuntos
Imagem de Difusão por Ressonância Magnética , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagem de Difusão por Ressonância Magnética/métodos , Encéfalo , Imageamento por Ressonância Magnética , Software
5.
J Transl Med ; 21(1): 187, 2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-36894992

RESUMO

BACKGROUND: Emerging evidence suggests that DNA methylation can be affected by physical activities and is associated with cardiac fibrosis. This translational research examined the implications of DNA methylation associated with the high-intensity interval training (HIIT) effects on cardiac fibrosis in patients with heart failure (HF). METHODS: Twelve HF patients were included and received cardiovascular magnetic resonance imaging with late gadolinium enhancement for cardiac fibrosis severity and a cardiopulmonary exercise test for peak oxygen consumption ([Formula: see text]O2peak). Afterwards, they underwent 36 sessions of HIIT at alternating 80% and 40% of [Formula: see text]O2peak for 30 min per session in 3-4 months. Human serum from 11 participants, as a means to link cell biology to clinical presentations, was used to investigate the exercise effects on cardiac fibrosis. Primary human cardiac fibroblasts (HCFs) were incubated in patient serum, and analyses of cell behaviour, proteomics (n = 6) and DNA methylation profiling (n = 3) were performed. All measurements were conducted after completing HIIT. RESULTS: A significant increase (p = 0.009) in [Formula: see text]O2peak (pre- vs. post-HIIT = 19.0 ± 1.1 O2 ml/kg/min vs. 21.8 ± 1.1 O2 ml/kg/min) was observed after HIIT. The exercise strategy resulted in a significant decrease in left ventricle (LV) volume by 15% to 40% (p < 0.05) and a significant increase in LV ejection fraction by approximately 30% (p = 0.010). LV myocardial fibrosis significantly decreased from 30.9 ± 1.2% to 27.2 ± 0.8% (p = 0.013) and from 33.4 ± 1.6% to 30.1 ± 1.6% (p = 0.021) in the middle and apical LV myocardium after HIIT, respectively. The mean single-cell migration speed was significantly (p = 0.044) greater for HCFs treated with patient serum before (2.15 ± 0.17 µm/min) than after (1.11 ± 0.12 µm/min) HIIT. Forty-three of 1222 identified proteins were significantly involved in HIIT-induced altered HCF activities. There was significant (p = 0.044) hypermethylation of the acyl-CoA dehydrogenase very long chain (ACADVL) gene with a 4.474-fold increase after HIIT, which could activate downstream caspase-mediated actin disassembly and the cell death pathway. CONCLUSIONS: Human investigation has shown that HIIT is associated with reduced cardiac fibrosis in HF patients. Hypermethylation of ACADVL after HIIT may contribute to impeding HCF activities. This exercise-associated epigenetic reprogramming may contribute to reduce cardiac fibrosis and promote cardiorespiratory fitness in HF patients. TRIAL REGISTRATION: NCT04038723. Registered 31 July 2019, https://clinicaltrials.gov/ct2/show/NCT04038723 .


Assuntos
Insuficiência Cardíaca , Treinamento Intervalado de Alta Intensidade , Humanos , Treinamento Intervalado de Alta Intensidade/métodos , Metilação de DNA/genética , Meios de Contraste , Gadolínio , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/terapia , Consumo de Oxigênio
6.
Radiol Med ; 128(9): 1148-1161, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37462887

RESUMO

OBJECTIVES: Glymphatic system maintains brain fluid circulation via active transportation of astrocytic aquaporin-4 in perivascular space. The diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) is an established method measuring perivascular glymphatic activity, but comprehensive investigations into its influential factors are lacking. METHODS: Community-dwelling older adults underwent brain MRI scans, neuropsychiatric, and multi-domain assessments. Blood biomarker tests included glial fibrillary acidic protein (GFAP) for astrocyte injury. RESULTS: In 71 enrolled participants, the DTI-ALPS index was associated with modifiable factors, including lipid profile (high-density lipoprotein, r = 0.396; very-low-density lipoprotein, r = - 0.342), glucose intolerance (diabetes mellitus, standardized mean difference (SMD) = 0.7662; glycated hemoglobin, r = - 0.324), obesity (body mass index, r = - 0.295; waist, r = - 0.455), metabolic syndrome (SMD = - 0.6068), cigarette-smoking (SMD = - 0.6292), and renal clearance (creatinine, r = - 0.387; blood urea nitrogen, r = - 0.303). Unmodifiable associative factors of DTI-ALPS were age (r = - 0.434) and sex (SMD = 1.0769) (all p < 0.05). A correlation of DTI-ALPS and blood GFAP was noticed (r = - 0.201, one-tailed t-test for the assumption that astrocytic injury impaired glymphatic activity, p = 0.046). Their cognitive correlations diverged, domain-specific for DTI-ALPS (Facial Memory Test, r = 0.272, p = 0.022) but global cognition-related for blood GFAP (MoCA, r = - 0.264, p = 0.026; ADAS-cog, r = 0.304, p = 0.010). CONCLUSION: This correlation analysis revealed multiple modifiable and unmodifiable association factors to the glymphatic image marker. The DTI-ALPS index correlated with various metabolic factors that are known to increase the risk of vascular diseases such as atherosclerosis. Furthermore, the DTI-ALPS index was associated with renal indices, and this connection might be a link of water regulation between the two systems. In addition, the astrocytic biomarker, plasma GFAP, might be a potential marker of the glymphatic system; however, more research is needed to confirm its effectiveness.


Assuntos
Sistema Glinfático , Humanos , Idoso , Sistema Glinfático/diagnóstico por imagem , Imagem de Tensor de Difusão , Astrócitos , Fatores de Risco , Encéfalo
7.
Cereb Cortex ; 31(10): 4652-4669, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-34013342

RESUMO

The human hippocampus is involved in forming new memories: damage impairs memory. The dual stream model suggests that object "what" representations from ventral stream temporal cortex project to the hippocampus via the perirhinal and then lateral entorhinal cortex, and spatial "where" representations from the dorsal parietal stream via the parahippocampal gyrus and then medial entorhinal cortex. The hippocampus can then associate these inputs to form episodic memories of what happened where. Diffusion tractography was used to reveal the direct connections of hippocampal system areas in humans. This provides evidence that the human hippocampus has extensive direct cortical connections, with connections that bypass the entorhinal cortex to connect with the perirhinal and parahippocampal cortex, with the temporal pole, with the posterior and retrosplenial cingulate cortex, and even with early sensory cortical areas. The connections are less hierarchical and segregated than in the dual stream model. This provides a foundation for a conceptualization for how the hippocampal memory system connects with the cerebral cortex and operates in humans. One implication is that prehippocampal cortical areas such as the parahippocampal TF and TH subregions and perirhinal cortices may implement specialized computations that can benefit from inputs from the dorsal and ventral streams.


Assuntos
Hipocampo/fisiologia , Memória/fisiologia , Vias Neurais/fisiologia , Adulto , Córtex Entorrinal/fisiologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Memória Episódica , Modelos Neurológicos , Giro Para-Hipocampal/fisiologia , Córtex Perirrinal , Lobo Temporal/fisiologia , Adulto Jovem
8.
Int J Mol Sci ; 23(20)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36293409

RESUMO

Mitochondria dysfunction is implicated in the pathogenesis of cardiovascular diseases (CVD). Exercise training is potentially an effective non-pharmacological strategy to restore mitochondrial health in CVD. However, how exercise modifies mitochondrial functionality is inconclusive. We conducted a systematic review using the PubMed; Scopus and Web of Science databases to investigate the effect of exercise training on mitochondrial function in CVD patients. Search terms included "mitochondria", "exercise", "aerobic capacity", and "cardiovascular disease" in varied combination. The search yielded 821 records for abstract screening, of which 20 articles met the inclusion criteria. We summarized the effect of exercise training on mitochondrial morphology, biogenesis, dynamics, oxidative capacity, antioxidant capacity, and quality. Amongst these parameters, only oxidative capacity was suitable for a meta-analysis, which demonstrated a significant effect size of exercise in improving mitochondrial oxidative capacity in CVD patients (SMD = 4.78; CI = 2.99 to 6.57; p < 0.01), but with high heterogeneity among the studies (I2 = 75%, p = 0.003). Notably, aerobic exercise enhanced succinate-involved oxidative phosphorylation. The majority of the results suggested that exercise improves morphology and biogenesis, whereas findings on dynamic, antioxidant capacity, and quality, were inadequate or inconclusive. A further randomized controlled trial is clearly required to explain how exercise modifies the pathway of mitochondrial quantity and quality in CVD patients.


Assuntos
Antioxidantes , Doenças Cardiovasculares , Humanos , Exercício Físico , Doenças Cardiovasculares/terapia , Mitocôndrias , Succinatos
9.
Magn Reson Med ; 86(3): 1514-1530, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33960501

RESUMO

PURPOSE: Recent advances in diffusion-weighted MRI provide "restricted diffusion signal fraction" and restricting pore size estimates. Materials based on co-electrospun oriented hollow cylinders have been introduced to provide validation for such methods. This study extends this work, exploring accuracy and repeatability using an extended acquisition on a 300 mT/m gradient human MRI scanner, in substrates closely mimicking tissue, that is, non-circular cross-sections, intra-voxel fiber crossing, intra-voxel distributions of pore-sizes, and smaller pore-sizes overall. METHODS: In a single-blind experiment, diffusion-weighted data were collected from a biomimetic phantom on a 3T Connectom system using multiple gradient directions/diffusion times. Repeated scans established short-term and long-term repeatability. The total scan time (54 min) matched similar protocols used in human studies. The number of distinct fiber populations was estimated using spherical deconvolution, and median pore size estimated through the combination of CHARMED and AxCaliber3D framework. Diffusion-based estimates were compared with measurements derived from scanning electron microscopy. RESULTS: The phantom contained substrates with different orientations, fiber configurations, and pore size distributions. Irrespective of one or two populations within the voxel, the pore-size estimates (~5 µm) and orientation-estimates showed excellent agreement with the median values of pore-size derived from scanning electron microscope and phantom configuration. Measurement repeatability depended on substrate complexity, with lower values seen in samples containing crossing-fibers. Sample-level repeatability was found to be good. CONCLUSION: While no phantom mimics tissue completely, this study takes a step closer to validating diffusion microstructure measurements for use in vivo by demonstrating the ability to quantify microgeometry in relatively complex configurations.


Assuntos
Biomimética , Imagem de Difusão por Ressonância Magnética , Encéfalo , Humanos , Microscopia Eletrônica de Varredura , Imagens de Fantasmas , Método Simples-Cego
10.
Cereb Cortex ; 30(11): 5830-5843, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32548630

RESUMO

The direct connections of the orbitofrontal cortex (OFC) were traced with diffusion tractography imaging and statistical analysis in 50 humans, to help understand better its roles in emotion and its disorders. The medial OFC and ventromedial prefrontal cortex have direct connections with the pregenual and subgenual parts of the anterior cingulate cortex; all of which are reward-related areas. The lateral OFC (OFClat) and its closely connected right inferior frontal gyrus (rIFG) have direct connections with the supracallosal anterior cingulate cortex; all of which are punishment or nonreward-related areas. The OFClat and rIFG also have direct connections with the right supramarginal gyrus and inferior parietal cortex, and with some premotor cortical areas, which may provide outputs for the OFClat and rIFG. Another key finding is that the ventromedial prefrontal cortex shares with the medial OFC especially strong outputs to the nucleus accumbens and olfactory tubercle, which comprise the ventral striatum, whereas the other regions have more widespread outputs to the striatum. Direct connections of the OFC and IFG were with especially the temporal pole part of the temporal lobe. The left IFG, which includes Broca's area, has direct connections with the left angular and supramarginal gyri.


Assuntos
Vias Neurais/anatomia & histologia , Córtex Pré-Frontal/anatomia & histologia , Adulto , Idoso , Imagem de Tensor de Difusão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
BMC Geriatr ; 21(1): 86, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516190

RESUMO

BACKGROUND: Age-related sarcopenia meaningfully increases the risks of functional limitations and mortality in the older adults. Although circulating microRNAs (c-miRNAs) are associated with aging-related cellular senescence and inflammation, the relationships between c-miRNAs and sarcopenia in the older adults remain unclear. This study investigates whether circulating myo-miRNAs and inflammation-related miRNAs are associated with sarcopenia in the older adults. METHODS: This investigation recruited 77 eligible subjects (41 males and 36 females) from 597 community-dwelling older adults, and then divided them into normal (n = 24), dynapenic (loss of muscular function without mass, n = 35), and sarcopenic groups (loss of muscular function with mass, n = 18). Moreover, myo- (c-miRNA-133a and c-miRNA-486) and inflammation- (c-miRNA-21 and c-miRNA-146a) related miRNAs, as well as, inflammatory-related cytokine and peroxide levels in plasma were determined using quantitative polymerase chain reaction and ELISA, respectively. RESULTS: Sarcopenic group exhibited lesser skeletal muscle mass index (SMI), handgrip strength, and gait speed, as well as, lower c-miR-486 and c-miR-146a levels, compared to those of normal and dynapenic groups. Moreover, c-miR-486 level was positively related to SMI (r = 0.334, P = 0.003), whereas c-miR-146a level was positively associated with SMI (r = 0.240, P = 0.035) and handgrip strength (r = 0.253, P = 0.027). In the receiver operating characteristic analysis for predicting sarcopenia, the area under the curve in c-miR-486 was 0.708 (95% confidence interval: 0.561-0.855, P = 0.008) and c-miR-146a was 0.676 (95% CI: 0.551-0.801, P = 0.024). However, no significant relationships were observed between SMI/handgrip strength/gait speed and plasma myeloperoxidase/interleukin-1훽/interleukin-6 levels. CONCLUSIONS: Myo-miRNA (c-miR-486) and inflammation-related miRNA (c-miR-146a) are superior to inflammatory peroxide/cytokines in plasma for serving as critical biomarkers of age-related sarcopenia.


Assuntos
MicroRNA Circulante , MicroRNAs , Sarcopenia , Idoso , Biomarcadores , Feminino , Força da Mão , Humanos , Masculino , Sarcopenia/diagnóstico
12.
J Biomed Inform ; 111: 103576, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33010424

RESUMO

Electronic health records (EHRs) often suffer missing values, for which recent advances in deep learning offer a promising remedy. We develop a deep learning-based, unsupervised method to impute missing values in patient records, then examine its imputation effectiveness and predictive efficacy for peritonitis patient management. Our method builds on a deep autoencoder framework, incorporates missing patterns, accounts for essential relationships in patient data, considers temporal patterns common to patient records, and employs a novel loss function for error calculation and regularization. Using a data set of 27,327 patient records, we perform a comparative evaluation of the proposed method and several prevalent benchmark techniques. The results indicate the greater imputation performance of our method relative to all the benchmark techniques, recording 5.3-15.5% lower imputation errors. Furthermore, the data imputed by the proposed method better predict readmission, length of stay, and mortality than those obtained from any benchmark techniques, achieving 2.7-11.5% improvements in predictive efficacy. The illustrated evaluation indicates the proposed method's viability, imputation effectiveness, and clinical decision support utilities. Overall, our method can reduce imputation biases and be applied to various missing value scenarios clinically, thereby empowering physicians and researchers to better analyze and utilize EHRs for improved patient management.


Assuntos
Aprendizado Profundo , Registros Eletrônicos de Saúde , Confiabilidade dos Dados , Humanos , Projetos de Pesquisa
13.
Adv Exp Med Biol ; 1077: 197-224, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30357691

RESUMO

Hydrogels are three-dimensional hydrophilic polymeric networks that can be made from a wide range of natural and synthetic polymers. This review discusses recent advanced engineering methods to fabricate hydrogels for biomedical applications with emphasis in cardiac constructs and wound healing. Layer-by-Layer (LbL) assembly offers a tissue-engineered construct with robust and highly ordered structures for cell proliferation and differentiation. Three-dimensional printings, including inkjet printing, fused deposition modeling, and stereolithographic apparatus, have been widely employed to fabricate complex structures (e.g., heart valves). Moreover, the state-of-the-art design of intelligent/stimulus-responsive hydrogels can be used for a wide range of biomedical applications, including drug delivery, glucose delivery, shape memory, wound dressings, and so on. In the future, an increasing number of hydrogels with tunable mechanical properties and versatile functions will be developed for biomedical applications by employing advanced engineering techniques with novel material design.


Assuntos
Hidrogéis , Engenharia Tecidual , Sistemas de Liberação de Medicamentos , Valvas Cardíacas , Humanos , Polímeros , Impressão Tridimensional , Alicerces Teciduais
14.
Biochim Biophys Acta ; 1863(9): 2212-20, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27220534

RESUMO

A negative-pressure of 125mmHg (NP) has been widely used to treat chronic wounds in modern medicine. Keratinocytes under NP treatment have shown accelerated cell movement and decreased E-cadherin expression. However, the molecular mechanism of E-cadherin regulation under NP remains incompletely understood. Therefore, we investigated the E-cadherin regulation in keratinocytes (HaCaT cells) under NP. HaCaT cells were treated at ambient pressure (AP) and NP for 12h. Cell movement was measured by traditional and electric wound healing assays at the 2 different pressures. Mutants with overexpression of p120-catenin (p120(ctn)) were used to observe the effect of NP on p120(ctn) and E-cadherin expression during wound healing. Cell fractionation and immunoblotting data showed that NP increased Y228-phosphorylated p120(ctn) level and resulted in the translocation of p120(ctn) from the plasma membrane to cytoplasm. Immunofluorescence images revealed that NP decreased the co-localization of p120(ctn) and E-cadherin on the plasma membrane. Knockdown of p120(ctn) reduced E-cadherin expression and accelerated cell movement under AP. Overexpression of the Y228-phosphorylation-mimic p120(ctn) decreased E-cadherin membrane expression under both AP and NP. Phosphorylation-deficient mutants conferred restored adherens junctions (AJs) under NP. The Src inhibitor blocked the phosphorylation of p120(ctn) and impeded cell migration under NP. In conclusion, Src-dependent phosphorylation of p120(ctn) can respond rapidly to NP and contribute to E-cadherin downregulation. The NP-induced disassembly of the AJ further accelerates wound healing.


Assuntos
Junções Aderentes/metabolismo , Cateninas/metabolismo , Queratinócitos/metabolismo , Queratinócitos/patologia , Pressão , Cicatrização , Caderinas/metabolismo , Linhagem Celular , Movimento Celular , Regulação para Baixo , Técnicas de Silenciamento de Genes , Humanos , Modelos Biológicos , Fenótipo , Fosforilação , Fosfotirosina/metabolismo , Transporte Proteico , Frações Subcelulares/metabolismo , Quinases da Família src/metabolismo , delta Catenina
15.
BMC Cancer ; 16(1): 800, 2016 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-27737648

RESUMO

BACKGROUND: N-cadherin is a trans-membrane adhesion molecule associated with advanced carcinoma progression and poor prognosis. The effect of N-cadherin on matrix metalloproteinase 9 (MMP-9) regulation is implicated in human nasopharyngeal carcinoma (NPC) cell invasion. METHODS AND RESULTS: Exposure of NPC cells to phorbol-12-myristate-13-acetate (PMA) or macrophage conditioned media (CM) upregulated MMP-9 and N-cadherin cleavage, which resulted in NPC cell invasion. MMP-9 cleaved the extracellular domain of N-cadherin, which was further cleaved by γ-secretase with PMA or macrophage-CM treatment. The extracellular cleavage of N-cadherin was inhibited with treatment with an MMP inhibitor and MMP-9 siRNA, whereas the intracellular cleavage of N-cadherin was inhibited by treatment with a γ-secretase inhibitor (γI), which resulted in enhanced accumulation of N-cadherin C-terminal fragment (CTF1, ~40 kDa). CTF2/N-cad (CTF2), a product of the γ-secretase cleavage of N-cadherin, was released and translocated into the nuclear compartment in PMA-treated cells. Moreover, CTF2 enhanced the effect of PMA-mediated MMP-9 gene expression as assessed by treatment with γI or overexpression with exogenous CTF2. Additionally, siRNA silencing of N-cadherin decreased PMA-mediated MMP-9 expression and cell invasion. The outside-in signaling effect of MMP-9 in macrophage CM- or PMA-treated cell cultures significantly enhanced NPC cell invasion via N-cadherin cleavage. CONCLUSION: Extracellular and intracellular cleavage of N-cadherin might be involved in elevated MMP-9 expression enhancing tumor cell invasion. Furthermore, N-cadherin-affected tumor progression might be via enhanced MMP-9 signaling in a cross-talk regulatory mechanism. N-cadherin might contribute to the invasive characteristics of carcinoma cells by upregulating MMP-9, thereby leading to increased aggressive metastasis.


Assuntos
Caderinas/metabolismo , Carcinoma/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Carcinoma/genética , Carcinoma/patologia , Linhagem Celular Tumoral , Movimento Celular , Núcleo Celular , Expressão Gênica , Humanos , Macrófagos/metabolismo , Metaloproteinase 9 da Matriz/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Invasividade Neoplásica , Ligação Proteica , Transporte Proteico , Proteólise , Transdução de Sinais
16.
Eur J Appl Physiol ; 116(11-12): 2375-2388, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27761657

RESUMO

PURPOSE: Exercise training improves endothelium-dependent vasodilation, whereas hypoxic stress causes vascular endothelial dysfunction. Monocyte-derived endothelial progenitor cells (Mon-EPCs) contribute to vascular repair process by differentiating into endothelial cells. This study investigates how high-intensity interval (HIT) and moderate-intensity continuous (MCT) exercise training affect circulating Mon-EPC levels and EPC functionality under hypoxic condition. METHODS: Sixty healthy sedentary males were randomized to engage in either HIT (3-min intervals at 40 and 80 % VO2max for five repetitions, n = 20) or MCT (sustained 60 % VO2max, n = 20) for 30 min/day, 5 days/week for 6 weeks, or to a control group (CTL) that did not received exercise intervention (n = 20). Mon-EPC characteristics and EPC functionality under hypoxic exercise (HE, 100 W under 12 % O2) were determined before and after HIT, MCT, and CTL. RESULTS: The results demonstrated that after the intervention, the HIT group exhibited larger improvements in VO2peak, estimated peak cardiac output (QC), and estimated peak perfusions of frontal cerebral lobe (QFC) and vastus lateralis (QVL) than the MCT group. Furthermore, HIT (a) increased circulating CD14++/CD16-/CD34+/KDR+ (Mon-1 EPC) and CD14++/CD16+/CD34+/KDR+ (Mon-2 EPC) cell counts, (b) promoted the migration and tube formation of EPCs, (c) diminished the shedding of endothelial (CD34-/KDR+/phosphatidylserine+) cells, and (d) elevated plasma nitrite plus nitrate, stromal cell-derived factor-1, matrix metalloproteinase-9, and vascular endothelial growth factor-A concentrations at rest or following HE, compared to those of MCT. In addition, Mon-1 and -2 EPC counts were directly related to VO2peak and estimated peak QC, QFC, and QVL. CONCLUSIONS: HIT is superior to MCT for improving hemodynamic adaptation and Mon-EPC production. Moreover, HIT effectively enhances EPC functionality and suppresses endothelial injury undergoing hypoxia.


Assuntos
Células Endoteliais/fisiologia , Células Progenitoras Endoteliais/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Hipóxia/prevenção & controle , Hipóxia/fisiopatologia , Movimento Celular/fisiologia , Células Endoteliais/citologia , Células Progenitoras Endoteliais/citologia , Terapia por Exercício/métodos , Humanos , Hipóxia/diagnóstico , Masculino , Resultado do Tratamento , Adulto Jovem
17.
Phys Chem Chem Phys ; 17(5): 3482-9, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25533311

RESUMO

Gasochromic VO2 thin films were fabricated by the sol-gel spin-coating technique. The results of X-ray absorption spectroscopy and resonant inelastic X-ray scattering spectroscopy reveal that the origin of gasochromic coloration in VO2 is strongly related to the modulation of its structure and the electron-electron correlation. Upon gasochromic coloration, not only does the valence state change with the incorporation of hydrogen, but also the film undergoes the modification of the local atomic structure. The structural distortion varies the strength of hybridization of the O 2p-V 3d states and the bond distance of V-O and V-O varies. In the hydric process, the local atomic structure of VO2 changes from that of an un-symmetric to that of a symmetric V-O framework. The incorporated hydrogen adds electrons into the V 3d t2g orbital, enhancing the electron-electron correlation by reducing the V-V distance. This work presents a new physical insight in which the modulation of the electron-electron correlation is exploited to control the bleached and colored states, giving rise to the gasochromic phenomenon. The strong correlation among atomic spatial rearrangement, electronic structures, and transmittance supports a cooperative mechanism of the VO2 gasochromic transition. These results reveal a clear correlation between the dynamics of the lattice structure and the electronic properties and suggest a possible pathway to gasochromism and elucidation of its mechanism.

18.
Apoptosis ; 19(3): 527-41, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24264887

RESUMO

Autophagy and endoplasmic reticulum (ER) stress response is important for cancer cells to maintain malignancy and resistance to therapy. trans-Resveratrol (RSV), a non-flavonoid agent, has been shown to induce apoptosis in human nasopharyngeal carcinoma (NPC) cells. In this study, the involvements of tumor-specific ER stress and autophagy in the RSV-mediated apoptosis were investigated. In addition to traditional autophagosomes, the images of transmission electron microscopy (TEM) indicated that RSV markedly induced larger, crescent-shaped vacuoles with single-layered membranes whose the expanded cisternae contains multi-lamellar membrane structures. Prolonged exposure to RSV induced a massive accumulation of ER expansion. Using an EGFP-LC3B transfection and confocal laser microscopy approach, we found RSV-induced EGFP-LC3 puncta co-localized with ER-tracker red dye, implicating the involvement of LC3II in ER expansion. The proapoptotic effect of RSV was enhanced after suppression of autophagy by ATG7 siRNA or blocking the autophagic flux by bafilomycin A1, but that was not changed after targeted silence of IRE1 or CHOP by siRNA. Using caspase inhibitors, we demonstrated the upregulation of caspase-12 (casp12) and the activation of casp4 were associated with the proapoptotic induction of RSV through the caspase-9/caspase-3 pathway. Intriguingly, siRNA knockdown of casp12, but not caspase-4, decreased the susceptibility of the NPC cells to RSV-mediated apoptosis. Further, we showed that RSV dose-dependently increased the ceramide accumulation as assessed by LC-MS/MS system. Using serine palmitoyltransferase (SPT, a key enzyme of de novo ceramide biosynthesis) inhibitors (L-cycloserine and myriocin), we found the increased ceramide accumulation was strongly correlated with the proapoptotic potential of RSV. This study revealed the ER expansion and upregulation of ER casp12 together may indicate profound biological effects of RSV and contributed to NPC cell death. Targeting the different status of ER stress may provide a possible strategy for cancer treatments.


Assuntos
Anticarcinógenos/farmacologia , Apoptose , Carcinoma de Células Escamosas/patologia , Caspases/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Neoplasias Nasofaríngeas/patologia , Estilbenos/farmacologia , Autofagia/efeitos dos fármacos , Caspase 12/metabolismo , Caspases Iniciadoras/metabolismo , Linhagem Celular Tumoral , Ceramidas/biossíntese , Retículo Endoplasmático/metabolismo , Estresse do Retículo Endoplasmático , Humanos , Resveratrol
19.
Clin Sci (Lond) ; 127(10): 589-602, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24863428

RESUMO

Lymphocytopenia is associated with an adverse prognosis in heart failure (HF). The present study investigated whether lymphocytopenia results from activated lymphocyte autophagy/apoptosis, which reflects haemodynamic inefficiency and functional aerobic impairment in patients with HF. One hundred and twenty-seven patients with HF were divided into three groups: HF with non- (lymphocytes ≥2000 cells/µl; n=45), mild (lymphocytes between ≥1500 cells/µl and <2000 cells/µl; n=39) and severe (lymphocytes <1500 cells/µl; n=43) lymphocytopenia. Lymphocyte autophagy/apoptosis, ventilatory/haemodynamic efficiencies and generic/disease-specific quality of life were analysed in these patients with HF and 35 normal counterparts. The results demonstrated that patients with HF with severe lymphocytopenia had (i) increased G-protein-coupled receptor kinase-2 (GRK-2) levels, (ii) lower mammalian target of rapamycin (mTOR) levels with higher lysosome-associated membrane protein-2 (LAMP-2) expression and Acridine Orange (AO) staining, (iii) lower mitochondrial transmembrane potential with higher caspase-3 activation and phosphatidylserine (PS) exposure, and (iv) greater extents of adrenaline (epinephrine)-induced apoptosis in lymphocytes, and higher plasma noradrenaline (norepinephrine)/adrenaline, myeloperoxidase and interleukin-6 concentrations than patients with HF without lymphocytopenia and normal counterparts did. Moreover, lymphocyte caspase-3 activation was an effect modifier, which modulated the correlation status between lymphocyte count and GRK-2 level. Lymphocyte count was positively correlated with peak cardiac output and peak oxygen consumption (VO2peak) in patients with HF. In addition, HF with lymphocytopenia was accompanied by lower Short Form-36 physical/mental component scores and increased Minnesota Living with Heart Failure Questionnaire scores. Therefore, we conclude that increased sympathetic activation and oxidative stress/pro-inflammatory status cause lymphocytopenia by activating programmed lymphocyte death in patients with HF. Moreover, a low lymphocyte count correlates with reduced haemodynamics and aerobic capacity, which reflects poor generic/disease-specific quality of life in patients with HF.


Assuntos
Apoptose/fisiologia , Autofagia/fisiologia , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/fisiologia , Linfócitos/fisiologia , Consumo de Oxigênio/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Catecolaminas/sangue , Citocinas/sangue , Eritropoetina/sangue , Feminino , Quinase 2 de Receptor Acoplado a Proteína G/sangue , Insuficiência Cardíaca/sangue , Humanos , Linfócitos/metabolismo , Linfopenia/sangue , Linfopenia/fisiopatologia , Proteína 2 de Membrana Associada ao Lisossomo/sangue , Masculino , Potencial da Membrana Mitocondrial/fisiologia , Pessoa de Meia-Idade , Peróxidos/sangue , Qualidade de Vida , Análise de Regressão , Inquéritos e Questionários , Serina-Treonina Quinases TOR/sangue
20.
Acta Cardiol Sin ; 30(5): 353-9, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27122811

RESUMO

UNLABELLED: Reduced exercise capacity negatively affects the ability of patients with heart failure (HF) to perform activities required for daily life, further decreasing their independence and quality of life (QoL). Cardiac rehabilitation (CR) can effectively improve aerobic fitness and overall health status in patients with HF. Low referral rate is an important limitation that may impede successful CR, whereas the automatic referral and liaison strategies performed by some healthcare providers manifestly increase the CR referral rate. However, there is still controversy regarding the most effective exercise strategy for improving hemodynamic efficiency during daily activities in the HF population. Aerobic interval training (AIT), that includes alternating high- and low-intensity exercise sessions, may be a more effective modality for improving functional capacity than traditional moderate continuous training (MCT) in patients with HF. A novel AIT regimen designed in our previous study may substantially enhance the ability of ventilation-perfusion matching during exercise, which effects are accompanied by an improved global and disease-specific QoL in HF patients. Conversely, the traditional MCT regimen may only maintain these physiologic responses to exercise at pre-interventional status. By elucidating the relationship between physical activity and hemodynamic property, this review attempts to provide a CR strategy for developing suitable exercise prescription that ameliorates hemodynamic disturbance, further retarding the disease progression and improving health-related QoL in patients with HF. KEY WORDS: Aerobic capacity; Heart failure; Hemodynamics; Rehabilitation.

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