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1.
Immunity ; 57(8): 1780-1795.e6, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-38843835

RESUMEN

Macrophages elicit immune responses to pathogens through induction of inflammatory genes. Here, we examined the role of three variants of the SWI/SNF nucleosome remodeling complex-cBAF, ncBAF, and PBAF-in the macrophage response to bacterial endotoxin (lipid A). All three SWI/SNF variants were prebound in macrophages and retargeted to genomic sites undergoing changes in chromatin accessibility following stimulation. Cooperative binding of all three variants associated with de novo chromatin opening and latent enhancer activation. Isolated binding of ncBAF and PBAF, in contrast, associated with activation and repression of active enhancers, respectively. Chemical and genetic perturbations of variant-specific subunits revealed pathway-specific regulation in the activation of lipid A response genes, corresponding to requirement for cBAF and ncBAF in inflammatory and interferon-stimulated gene (ISG) activation, respectively, consistent with differential engagement of SWI/SNF variants by signal-responsive transcription factors. Thus, functional diversity among SWI/SNF variants enables increased regulatory control of innate immune transcriptional programs, with potential for specific therapeutic targeting.


Asunto(s)
Ensamble y Desensamble de Cromatina , Proteínas Cromosómicas no Histona , Elementos de Facilitación Genéticos , Inflamación , Macrófagos , Factores de Transcripción , Macrófagos/inmunología , Macrófagos/metabolismo , Animales , Ratones , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Proteínas Cromosómicas no Histona/metabolismo , Proteínas Cromosómicas no Histona/genética , Inflamación/inmunología , Inflamación/genética , Elementos de Facilitación Genéticos/genética , Cromatina/metabolismo , Regulación de la Expresión Génica , Ratones Endogámicos C57BL , Inmunidad Innata , Humanos
3.
Genes Dev ; 34(21-22): 1407-1409, 2020 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-33872194

RESUMEN

Alternative polarization of macrophages induced by IL-4 is important for homeostasis and tissue repair. Downstream from IL-4 receptor signaling, STAT6 activation is transient, but induces stable transcriptional changes. These data suggest that STAT6 induces second messengers to carry out the alternative transcriptional program. In this issue of Genes & Development, Daniel and colleagues (pp. 1474-1492) identify EGR2 as a downstream regulator of STAT6 with broad functionality that further induces many transcription factors associated with alternative polarization. Identification of high EGR2 expression in a subset of mouse and human alveolar macrophages further highlights EGR2 as a conserved marker of alternatively activated macrophages.


Asunto(s)
Activación de Macrófagos , Macrófagos , Animales , Proteína 2 de la Respuesta de Crecimiento Precoz , Ratones , Factor de Transcripción STAT6 , Transducción de Señal
4.
Nano Lett ; 24(1): 187-194, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38088862

RESUMEN

Realistically, green manufacturing of transparent superhydrophobic surfaces (SHSs) and high liquid impalement resistance for outdoor engineering are very necessary but pretty challenging. To address this, an almost all-waterborne system composed of synthesized partially open-cage fluorinated polyhedral oligomeric silsesquioxane bearing a pair of -OH (poc-FPOSS-2OH), silica sol, and resin precursor is engineered. The transparent SHSs facilely formed by this system are featured with the exclusive presence of wrapped silica nanoparticle (SiNP) dendritic networks at solid-gas interfaces. The wrapped SiNP dendritic networks have a small aggregation size and low distribution depth, making SHSs highly transparent. The Si-O polymeric wrappers render mechanical flexibility to SiNP dendritic networks and thus enable transparent SHSs to resist high-speed water jet impinging with a Weber number of ≥19 800 in conjunction with the extremely low-surface-energy poc-FPOSS-2OH, which is the highest liquid impalement resistance so far among waterborne SHSs, and can rival the state-of-the-art solventborne SHSs.

5.
Artículo en Inglés | MEDLINE | ID: mdl-39133260

RESUMEN

PURPOSE: Hydrogen sulfide (H2S) secreted by perivascular adipose tissue (PVAT) is a critical vasodilator, which might be involved during the pathogenesis of hypertension. The present study aimed to investigate the exact role of H2S on the regulation of PVAT anti-contraction by long-term exercise in obesity hypertension. METHODS: After the establishment of obesity hypertension (24 weeks) through a high-fat diet, male Sprague-Dawley rats were randomly assigned to control group (HC), exercise group (HE), cystathionine γ-lyase (CSE) blocking group (HCB), and exercise combined with CSE blocking group (HEB). Exercise and CSE inhibitor regimens were performed throughout 13 weeks. RESULTS: After 13 weeks of intervention, blood pressure was significantly decreased by long-term exercise (HC vs. HE, P < 0.05) but not by exercise combined with the CSE inhibitor regimen. Meanwhile, the CSE inhibitor significantly blocked the production of H2S in PVAT even after exercise (HE vs. HEB, P < 0.05). Furthermore, long-term exercise altered the expressions of voltage-dependent K+ (Kv) channel subunits 7 (KCNQs), which were diminished by CSE inhibition in mesenteric arteries. As for vascular tension assessment, after incubation with or without KCNQ opener (retigabine), the anti-contractile effect of PVAT (with or without transferred bath solution of PVAT) was significantly enhanced by long-term exercise and eliminated by the CSE inhibitor regimen (P < 0.05); KCNQ inhibitor (XE991) blunted this effect except for HE. CONCLUSIONS: These results collectively suggest that endogenous H2S is a strong regulator of the anti-contractile effect of PVAT in obesity hypertension by long-term exercise, and KCNQ in the resistance artery might be involved during this process but not the only target channel mediated by H2S.

6.
Biol Reprod ; 109(1): 53-64, 2023 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-37154585

RESUMEN

Aerobic exercises could improve the sperm motility of obese individuals. However, the underlying mechanism has not been fully elucidated, especially the possible involvement of the epididymis in which sperm acquire their fertilizing capacity. This study aims to investigate the benefit effect of aerobic exercises on the epididymal luminal milieu of obese rats. Sprague-Dawley male rats were fed on a normal or high-fat diet (HFD) for 10 weeks and then subjected to aerobic exercises for 12 weeks. We verified that TRPA1 was located in the epididymal epithelium. Notably, aerobic exercises reversed the downregulated TRPA1 in the epididymis of HFD-induced obese rats, thus improving sperm fertilizing capacity and Cl- concentration in epididymal milieu. Ussing chamber experiments showed that cinnamaldehyd (CIN), agonist of TRPA1, stimulated an increase of the short-circuit current (ISC) in rat cauda epididymal epithelium, which was subsequently abolished by removing the ambient Cl- and HCO3-. In vivo data revealed that aerobic exercises increased the CIN-stimulated Cl- secretion rate of epididymal epithelium in obese rats. Pharmacological experiments revealed that blocking cystic fibrosis transmembrane regulator (CFTR) and Ca2+-activated Cl- channel (CaCC) suppressed the CIN-stimulated anion secretion. Moreover, CIN application in rat cauda epididymal epithelial cells elevated intracellular Ca2+ level, and thus activate CACC. Interfering with the PGHS2-PGE2-EP2/EP4-cAMP pathway suppressed CFTR-mediated anion secretion. This study demonstrates that TRPA1 activation can stimulate anion secretion via CFTR and CaCC, which potentially forming an appropriate microenvironment essential for sperm maturation, and aerobic exercises can reverse the downregulation of TRPA1 in the epididymal epithelium of obese rats.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Epidídimo , Ratas , Masculino , Animales , Ratas Sprague-Dawley , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Epidídimo/metabolismo , Dieta Alta en Grasa/efectos adversos , Calcio/metabolismo , Motilidad Espermática , Semen/metabolismo , Canales de Cloruro/metabolismo , Canales de Cloruro/farmacología , Aniones/metabolismo , Aniones/farmacología , Proteínas Portadoras/metabolismo , Homeostasis , Cloruros/metabolismo , Cloruros/farmacología
7.
Trends Immunol ; 41(2): 126-140, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31928914

RESUMEN

Epigenetic regulation plays an important role in controlling the activation, timing, and resolution of innate immune responses in macrophages. Previously, SWI/SNF chromatin remodeling was found to define the kinetics and selectivity of gene activation in response to microbial ligands; however, these studies do not reflect a comprehensive understanding of SWI/SNF complex regulation. In 2018, a new variant of the SWI/SNF complex was identified with unknown function in inflammatory gene regulation. Here, we summarize the biochemical and genomic properties of SWI/SNF complex variants and the potential for increased regulatory control of innate immune transcriptional programs in light of such biochemical diversity. Finally, we review the development of SWI/SNF complex chemical inhibitors and degraders that could be used to modulate immune responses.


Asunto(s)
Ensamble y Desensamble de Cromatina , Proteínas Cromosómicas no Histona , Macrófagos , Proteínas Cromosómicas no Histona/genética , Proteínas Cromosómicas no Histona/metabolismo , Epigénesis Genética , Humanos , Macrófagos/inmunología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
8.
BMC Musculoskelet Disord ; 24(1): 345, 2023 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-37143006

RESUMEN

BACKGROUND: Early ambulation in patients undergoing transforaminal lumbar interbody fusion (TLIF) surgery is recommended, however, the precise time interval after open surgery has never been specified. Current retrospective analysis was conducted aiming to clarify an accurate time interval. METHODS: A retrospective analysis of eligible patients was conducted using the databases of the Bone Surgery Department, Third Affiliated Hospital of Sun Yat-sen University from 2016 to 2021. Data pertaining to postoperative hospital stay length, expenses, incidence of complications were extracted and compared using Pearson's χ2 or Student's t-tests. A multivariate linear regression model was conducted to identify the relationship between length of hospital stay (LOS) and other outcomes of interest. A propensity analysis was conducted to minimize bias and to evaluate the reliability of results. RESULTS: A total of 303 patients met the criteria and were included for the data analysis. Multivariate linear regression results demonstrated that a high ASA grade (p = 0.016), increased blood loss (p = 0.003), cardiac disease (p < 0.001), occurrence of postoperative complications(p < 0.001) and longer ambulatory interval (p < 0.001) was significantly associated with an increased LOS. The cut-off analysis manifested that patients should start mobilization within 3 days after open TLIF surgery (B = 2.843, [1.395-4.292], p = 0.0001). Further comparative analysis indicated that patients who start ambulatory exercise within 3 days have shorter LOS (8.52 ± 3.28d vs 12.24 ± 5.88d, p < 0.001), total expenses ( 9398.12 ± 2790.82vs 10701.03 ± 2994.03 [USD], p = 0.002). Propensity analysis revealed such superiority was stable along with lower incidence of postoperative complications (2/61 vs 8/61, p = 0.0048). CONCLUSIONS: The current analysis suggested that ambulatory exercise within 3 days for patients who underwent open TLIF surgery was significantly associated with reduced LOS, total hospital expenses, and postoperative complications. Further causal relationship would be confirmed by future randomized controlled trials.


Asunto(s)
Procedimientos Quirúrgicos Mínimamente Invasivos , Fusión Vertebral , Humanos , Resultado del Tratamiento , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Estudios Retrospectivos , Vértebras Lumbares/cirugía , Ambulación Precoz , Reproducibilidad de los Resultados , Fusión Vertebral/efectos adversos , Fusión Vertebral/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología
9.
Int J Mol Sci ; 23(19)2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36232489

RESUMEN

We aimed to investigate the efficacy of exercise on preventing arterial stiffness and the potential role of sympathetic nerves within perivascular adipose tissue (PVAT) in pressure-overload-induced heart failure (HF) mice. Eight-week-old male mice were subjected to sham operation (SHAM), transverse aortic constriction-sedentary (TAC-SE), and transverse aortic constriction-exercise (TAC-EX) groups. Six weeks of aerobic exercise training was performed using a treadmill. Arterial stiffness was determined by measuring the elastic modulus. The elastic and collagen fibers of the aorta and sympathetic nerve distribution in PVAT were observed. Circulating noradrenaline (NE), expressions of ß3-adrenergic receptor (ß3-AR), and adiponectin in PVAT were quantified. During the recovery of cardiac function by aerobic exercise, thoracic aortic collagen elastic modulus (CEM) and collagen fibers were significantly decreased (p < 0.05, TAC-SE vs. TAC-EX), and elastin elastic modulus (EEM) was significantly increased (p < 0.05, TAC-SE vs. TAC-EX). Circulating NE and sympathetic nerve distribution in PVAT were significantly decreased (p < 0.05, TAC-SE vs. TAC-EX). The expression of ß3-AR was significantly reduced (p < 0.05, TAC-SE vs. TAC-EX), and adiponectin was significantly increased (p < 0.05, TAC-SE vs. TAC-EX) in PVAT. Regular aerobic exercise can effectively prevent arterial stiffness and extracellular matrix (ECM) remodeling in the developmental course of HF, during which sympathetic innervation and adiponectin within PVAT might be strongly implicated.


Asunto(s)
Insuficiencia Cardíaca , Condicionamiento Físico Animal , Sistema Nervioso Simpático , Rigidez Vascular , Animales , Masculino , Ratones , Adiponectina/metabolismo , Tejido Adiposo/metabolismo , Constricción , Elastina/metabolismo , Insuficiencia Cardíaca/metabolismo , Ratones Endogámicos C57BL , Norepinefrina/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Sistema Nervioso Simpático/fisiología
10.
Int J Obes (Lond) ; 45(9): 2048-2057, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34127804

RESUMEN

BACKGROUND/OBJECTIVES: Children and adolescents spend a substantial amount of time being sedentary. The impact of prolonged sedentary patterns on fat distribution has not been elucidated especially in the context of physical activity level. Our objective is to examine the independent and joint associations of prolonged sedentary patterns and physical activity level with fat distribution among children and adolescents. SUBJECTS/METHODS: This included US children (8-11 years) and adolescents (12-19 years) from the National Health and Nutrition Examination Survey 2003-2006. Sedentary patterns comprise accelerometer-measured average sedentary bout duration and self-reported time of sitting watching TV/videos. Fat distribution (trunk and total fat percentage) was determined via dual X-ray absorptiometry. RESULTS: Among 810 children and 2062 adolescents, average sedentary bout duration was associated with greater total and trunk fat percentages only among male children, after adjusting for moderate-to-vigorous physical activity (MVPA) level by accelerometer. Prolonged sitting watching TV/videos was associated with higher total and trunk fat percentages in male children and all adolescents, independent of levels of MVPA (all P for trend <0.05). Compared with ≤1 h/day, male children who spent ≥4 h/day sitting watching TV/videos had 4.43% higher trunk fat (95% CI, 1.69-7.17%), with similar associations for female (3.53%; 95% CI, 1.03-6.03%) and male adolescents (4.78%; 95% CI, 2.97-6.60%). About 13-17% children and adolescents spent <1 h on MVPA and ≥4 h sitting watching TV/videos per day. Compared with the most active group (MVPA ≥ 1 h/day and sitting watching TV/videos ≤1 h/day), trunk fat in this least active group was 6.21% higher in female children, 9.90% higher in male children, 6.84% higher in female adolescents, and 5.36% higher in male adolescents. CONCLUSIONS: Prolonged time spent on sitting watching TV/videos was associated with fat accumulation among children and adolescents, independent of physical activity level.


Asunto(s)
Distribución de la Grasa Corporal/estadística & datos numéricos , Obesidad Infantil/fisiopatología , Conducta Sedentaria , Niño , Estudios Transversales , Femenino , Humanos , Masculino , Encuestas Nutricionales , Obesidad Infantil/clasificación , Obesidad Infantil/epidemiología , Autoinforme , Estados Unidos/epidemiología
11.
Clin Exp Pharmacol Physiol ; 48(5): 697-703, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-32893373

RESUMEN

This study investigated the function of perivascular adipose tissue (PVAT) on vascular contractility within resistant arteries in high-fat diet induced obese rats after long-term aerobic exercise. Male Sprague-Dawley rats were subjected to normal diet control group (N-CTRL), normal diet exercise group (N-EX), high-fat diet control group (H-CTRL), and high-fat diet exercise group (H-EX) (n = 8 in each group). After intervention, adipose tissues morphology was observed. Vasomotor function of mesenteric arteries with or without PVAT were assessed; mesenteric PVAT isolated from each group were transferred to chambers bath with untreated vessels (without PVAT) to evaluate the independent effect. Isolated PVAT was further pre-treated with inhibitor of cystathionine-γ-lyase (CSE), a key hydrogen sulphide (H2 S) enzyme. Results showed that the size of lipid droplet around mesenteric arteries from H-EX was significantly reduced (P < .05); uncoupling protein1 (UCP1) in PVAT from H-EX was enhanced. In N-CTRL, N-EX, and H-EX, vessels without PVAT showed higher sensitivity to serotonin (5-HT) than that with intact PVAT. Vascular tension by 5-HT was significantly reduced in H-EX than H-CTRL (P < .05) in vessels with PVAT. Transferred PVAT from H-EX compared with H-CTRL significantly reduced vascular sensitivity to 5-HT (P < .05), and this effect was eliminated through inhibiting CSE. In summary, the anti-contractile effect of PVAT on resistance artery was impaired in obesity but restored by long-term aerobic exercise. The function of PVAT modified by obesity or by exercise has an independent influence on vascular reactivity, and PVAT derived H2 S may participate in this process.


Asunto(s)
Tejido Adiposo , Animales , Dieta Alta en Grasa , Arterias Mesentéricas , Ratas , Ratas Sprague-Dawley
12.
Nano Lett ; 20(7): 4895-4900, 2020 07 08.
Artículo en Inglés | MEDLINE | ID: mdl-32567866

RESUMEN

Ultrafast oil/water separation based on tunable superwettability switch remains a big challenge. Here, inspired by the ultrafast water transport mechanism in sarracenia, we develop a micro/nanostructured porous membrane with conducting polymer nanotip arrays through the surface-initiated polymerizations. By modulating the height (ranging from 49-529 nm) and redox states of nanotips, a smart reversible superwettability switch is facile to obtain with contact angles of water/oil arranging from 161° to about 0°. Besides, liquid transport speed was accelerated more than 1.5 times by increasing the nanotip length. The water flux could reach up to 50326 L m-2 h-1 (1000 times that of a typical industrial ultrafiltration membrane). This is attributed to the stable and continuous water film along the nanotips, which provide a lubrication layer, leading to an increase of permeability. This work provides significant insights into macro/nanostructured membrane design for smart separation, blood lipid filtration, and smart nanoreactors with high permeability.

13.
Eat Weight Disord ; 26(2): 457-465, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32072570

RESUMEN

AIMS: This study investigated the effects of exercise and diet intervention on appetite-regulating hormones and subjective appetite changes in obese children and examined expressions of specific key microRNAs (miRNA, miR). METHODS: 16 obese children were included in a training program consisting of exercise and diet intervention for 6 weeks. Before and after the intervention, fasting blood was collected to determine appetite-regulating hormones (leptin, ghrelin, and orexin) and miRNA (miR-103a-3p and miR-200a-3p) levels; eating behavior of the children was reported using the Children Eating Behavior Questionnaire (CEBQ). RESULTS: The level of orexin was significantly decreased (P < 0.05), while ghrelin was significantly enhanced (P < 0.05) after 6 weeks. The scores of food responsiveness (FR) and enjoyment of food (EF) of the CEBQ were significantly decreased (P < 0.05) after intervention. The changes of leptin and that of SR were significantly correlated (r = - 0.455, P < 0.05), and the correlation between the alterations of orexin and that of EF was moderate with significance (r = 0.625, P < 0.05). miR-103a-3p expression was not statistically changed, while miR-200a-3p was significantly inhibited after 6-week intervention (P < 0.05). The correlation between relative changes of miR-103a-3p and that of leptin and orexin were both with significant difference (r = 0.413, P < 0.05; r = 0.409, P < 0.05), whereas the alterations of miR-200a-3p were not correlative with hormones or appetite sensation. CONCLUSION: Exercise combined with diet intervention for 6 weeks was effective in regulating appetite sensations and hormones in obese children, and miR-103a-3p and miR-200a-3p might provide a foundation for target biomarkers of appetite trait in modulating the energy balance control by exercise and dietary intervention. LEVEL OF EVIDENCE: Level III, case-control analytic study. TRIAL REGISTRATION: The trial was registered in ClinicalTrials.gov (NCT03762629).


Asunto(s)
MicroARNs , Apetito , Niño , Ejercicio Físico , Ayuno , Humanos , MicroARNs/genética , Obesidad/terapia
14.
Nanotechnology ; 31(44): 445602, 2020 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-32693391

RESUMEN

To address a challenge for decoration of noble metal nanoparticles (NMNPs)-shell on conducting polymer nanofiber (CPNF) electrodes (i.e. NMNP-shell/CPNF-core electrodes) for boosting electrochemical performances, a two-step strategy comprising chemical pre-deposition and electrochemical deposition is designed. The strategy shows a high universality in terms of the diversity of NMNP-shell elements (single-element: AgNP-shell, AuNP-shell, PtNP-shell, PdNP-shell; multi-element: Au/Pt/PdNP-shell) and the independence of conductive substrates of electrodes. The shells are composed of high-density NMNPs and have strong adhesion to CPNF-cores. It is demonstrated that in response to a specific applied electrical stimulus, the resulting low doping level of CPNFs facilitates the generation of high-density nucleation sites (small NMNPs) by chemical pre-deposition (as high capability of electron transfer and low resistance to electron transfer from CP chains to NM ions), which is indispensable for the formation of NMNP-shells on CPNF-cores by electrochemical deposition. The decoration of NMNP-shells can significantly enhance the electrochemical performances of CPNF electrodes. Moreover, the great practicality and reliability of NMNP-shell/CPNF-core electrodes in use as an electrocatalytic platform are confirmed. This universal strategy opens up a new avenue to construct high-dimension shell/core-nanostructured electrodes.

15.
Sheng Li Xue Bao ; 71(3): 478-484, 2019 Jun 25.
Artículo en Zh | MEDLINE | ID: mdl-31218339

RESUMEN

Irisin is a circulating myokine induced by exercise, which is a cleaved version of fibronectin type III domain containing protein 5 (FNDC5). It can promote the browning of white fat tissue, increase energy consumption, and decrease weight. Irisin plays an important role in the regulation of various diseases, such as diabetes and coronary heart disease. Different types of exercise have different effects on irisin level in blood circulation, and moderate exercise can reduce cardiovascular symptoms. In this paper, the cardiovascular protective effect of irisin and its research progress in the field of exercise are reviewed, hoping to provide a new target for the prevention and treatment of cardiovascular diseases.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Ejercicio Físico , Fibronectinas/fisiología , Diabetes Mellitus , Humanos , Músculo Esquelético , Medicina Deportiva
16.
Biol Sport ; 34(4): 313-321, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29472733

RESUMEN

This study was designed to investigate the effects of exogenous androgen and resistance exercise on skeletal muscle hypertrophy and the role of the mammalian target of rapamycin (mTOR) signalling during the process. A total of 24 male Sprague-Dawley rats were randomly assigned to sham operation and dihydrotestosterone (DHT) implantation groups with subgroups subjected to sedentary conditions or resistance exercise (SHAM+SED, SHAM+EX, DHT+SED, and DHT+EX). The experimental procedure lasted for 10 days. The mRNA expression of androgen receptor (AR) and insulin-like growth factor I (IGF-I), the expression of myosin heavy chain (MHC), as well as the phosphorylation statuses of AR, mTOR, p70 ribosomal S6 kinase (p70S6K), and eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) were determined in the white gastrocnemius muscle. The cross sectional area and wet mass of the muscle were also measured. The cross sectional area and MHC expression were significantly higher in SHAM+EX, DHT+SED, and DHT+EX than in SHAM+SED. There was no significant difference among groups in muscle mass. The mRNA expression of AR and IGF-I and the phosphorylation of mTOR, p70S6K, and 4EBP1 were significantly increased in DHT+SED and SHAM+EX and were significantly enhanced in DHT+EX compared with either DHT or exercise alone. These data show that DHT causes hypertrophy in skeletal muscle and that exercise has a synergistic effect on DHT-induced hypertrophy. Exercise enhances androgen-induced rapid anabolic action, which involves activation of the mTOR pathway.

17.
J Mater Sci Mater Med ; 26(3): 147, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25764082

RESUMEN

Numerous modification methods have been reported to enhance the corrosion resistance of magnesium with positive results. However, little attention has been paid on their impact on micro-environment, particularly the ion concentration and local pH value. In this study, two different coatings were prepared on magnesium, one with porous micro-arc oxidation (MAO) coating alone, and the other with additional polymer polyhydroxybutyrate (PHB) membrane using spinning technique. Their in vitro corrosional and biological behaviors were investigated and compared. Both coatings were found to reduce the degradation rate of magnesium, but an additionally deposited PHB membrane was superior to MAO-coated magnesium since it could produce a micro-environment with preferable local pH value and ion concentration for osteoblast proliferation. Our study suggests that micro-environment should be another critical issue in evaluation of a modification method for orthopaedic implants.


Asunto(s)
Materiales Biocompatibles Revestidos , Magnesio/química , Membranas Artificiales , Polímeros/química , Células 3T3 , Animales , Técnicas In Vitro , Ratones , Oxidación-Reducción
18.
Macromol Rapid Commun ; 35(5): 574-8, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24347343

RESUMEN

In this article, taurine, one of the small biomolecules associated with bone metabolism, is firstly utilized to induce the fabrication of nano-architectured conducting polypyrrole (NCPPy) on biomedical titanium in diverse pH values of phosphate buffer solution (PBS). Accordingly, the possible mechanism for the fabrication of NCPPy is proposed, which is dependent on the states of polytaurine from the polymerization of taurine, i.e., the inability of forming polytaurine and unordered restricted space results in taurine-incorporated and polytaurine-incorporated tightly packed nanoparticles (pH 6.2 and 8.0), respectively, and however, ordered restricted space constructed by polytaurine chains induces the fabrication of polytaurine-incorporated nanopillars (pH 6.8) and polytaurine-incorporated nanowire networks (pH 7.4).


Asunto(s)
Conductividad Eléctrica , Nanoestructuras/química , Nanotecnología/métodos , Polímeros/química , Pirroles/química , Taurina/química , Titanio/química , Técnicas Electroquímicas , Concentración de Iones de Hidrógeno , Nanoestructuras/ultraestructura , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
19.
J Mater Sci Mater Med ; 25(9): 2173-83, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25008369

RESUMEN

To effectively repair or replace damaged tissues, it is necessary to design three dimensional (3D) extracellular matrix (ECM) mimicking scaffolds with tunable biomechanical properties close to the desired tissue application. In the present work, gelatin methacrylate (GelMA) and dextran glycidyl methacrylate (DexMA) with tunable mechanical and biological properties were utilized to prepared novel bicomponent polymeric hydrogels by cross-linking polymerization using photoinitiation. We controlled the degree of substitution (DS) of glycidyl methacrylate in DexMA so that they could obtain relevant mechanical properties. The results indicated that copolymer hydrogels demonstrated a lower swelling ratio and higher compressive modulus as compared to the GelMA. Moreover, all of the hydrogels exhibited a honeycomb-like architecture, the pore sizes decreased as DS increased, and NIH-3T3 fibroblasts encapsulated in these hydrogels all exhibited excellent viability. These characteristics suggest a class of photocrosslinkable, tunable mechanically copolymer hydrogels that may find potential application in tissue engineering and regenerative medicine applications.


Asunto(s)
Gelatina , Hidrogeles , Metacrilatos , Procesos Fotoquímicos , Ingeniería de Tejidos , Andamios del Tejido , Animales , Matriz Extracelular , Ratones , Microscopía Electrónica de Rastreo , Células 3T3 NIH , Espectroscopía de Protones por Resonancia Magnética , Espectroscopía Infrarroja por Transformada de Fourier
20.
J Mater Sci Mater Med ; 25(8): 1875-84, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24831082

RESUMEN

To further enhance the biological properties of acid-etched microrough titanium surfaces, titania nanotextured thin films were produced by simple chemical oxidation, without significantly altering the existing topographical and roughness features. The nanotextured layers on titanium surfaces can be controllably varied by tuning the oxidation duration time. The oxidation treatment significantly reduced water contact angles and increased the surface energy compared to the surfaces prior to oxidation. The murine bone marrow stromal cells (BMSCs) were used to evaluate the bioactivity. In comparison, oxidative nanopatterning of microrough titanium surfaces led to improved attachment and proliferation of BMSCs. The rate of osteoblastic differentiation was also represented by the increased levels of alkaline phosphatase activity and mineral deposition. These data indicated that oxidative nanopatterning enhanced the biological properties of the microrough titanium surfaces by modulating their surface chemistry and nanotopography. Based on the proven mechanical interlocking ability of microtopographies, enhancement of multiple osteoblast functions attained by this oxidative nanopatterning is expected to lead to better implant osseointegration in vivo.


Asunto(s)
Nanotecnología , Osteogénesis , Titanio/química , Animales , Adhesión Celular , Proliferación Celular , Células Cultivadas , Células Madre Mesenquimatosas/citología , Ratones , Microscopía Electrónica de Rastreo , Oxidación-Reducción , Propiedades de Superficie , Humectabilidad
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