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1.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37833978

RESUMO

Cardiovascular aging has been reported to accelerate in spaceflights, which is a great potential risk to astronauts' health and performance. However, current exercise routines are not sufficient to reverse the adverse effects of microgravity exposure. Recently, salidroside (SAL), a valuable medicinal herb, has been demonstrated to display an important role for prevention and treatment in cardiovascular and other diseases. In the present work, Sprague-Dawley rats with four-week tail-suspension hindlimb-unloading were used to simulate microgravity effects on the cardiovascular system. We found that intragastrical administration of SAL not only significantly decreased the expressions of senescence biomarkers, such as P65 and P16, but also obviously increased the expressions of BK-dependent apoptotic genes, including the large-conductance calcium-activated K+ channel (BK), Bax, Bcl-2, and cleaved caspase-3, in vascular smooth muscle cells (VSMCs) in vivo and in vitro. In addition, relative non-coding RNAs were screened, and a luciferase assay identified that SAL increased apoptosis by activating LncRNA-FLORPAR, inhibiting miR-193, and then triggering the activity of the BK-α subunit. Our work indicated that SAL is a novel non-coding RNA modulator for regulating the LncRNA-FLORPAR sponging miR-193 pathway, which significantly promoted BK-dependent apoptosis and delayed cerebrovascular aging-like remodeling during simulated microgravity exposure. Our findings may provide a new approach to prevent cardiovascular aging in future spaceflights.


Assuntos
MicroRNAs , RNA Longo não Codificante , Ausência de Peso , Ratos , Animais , Ratos Sprague-Dawley , RNA Longo não Codificante/metabolismo , Apoptose , MicroRNAs/metabolismo , Senescência Celular/genética , Miócitos de Músculo Liso/metabolismo
2.
J Comp Physiol B ; 193(3): 329-350, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36988658

RESUMO

Loss of bone mass can occur in mammals after prolonged disuse but the situation for hibernators that are in a state of torpor for many months of the year is not yet fully understood. The present study assesses the bone remodeling mechanisms present in Daurian ground squirrels (Spermophilus dauricus) during hibernation as compared with a model of hindlimb disuse. Differences in microstructure, mechanical properties, bone remodeling-related proteins (Runx2, OCN, ALP, RANKL, CTK and MMP-9) and key proteins of Wnt/ß-catenin signaling pathway (GSK-3ß and phospho-ß-catenin) were evaluated in ground squirrels under 3 conditions: summer active (SA) vs. hibernation (HIB) vs. hindlimb unloaded (HLU). The results indicated that the body weight in HLU ground squirrels was lower than the SA group, and the middle tibia diameter in the HLU group was lower than that in SA and HIB groups. The thickness of cortical and trabecular bone in femurs from HLU ground squirrels was lower than in SA and HIB groups. Most parameters of the tibia in the HLU group were lower than those in SA and HIB groups, which indicated cortical bone loss in ground squirrels. Moreover, our data showed that the changes in microscopic parameters in the femur were more obvious than those in the tibia in HLU and HIB ground squirrels. The levels of Runx2 and ALP were lower in HLU ground squirrels than SA and HIB groups. The protein levels of OCN were unchanged in the three groups, but the protein levels of ALP were lower in the HLU group than in SA and HIB groups. RANKL, CTK and MMP-9 protein levels were significantly decreased in tibia of HLU ground squirrels as compared with SA and HIB groups. In addition, the protein expression levels of RANKL, CTK and MMP-9 showed no statistical difference between SA and HIB ground squirrels. Thus, the mechanisms involved in the balance between bone formation and resorption in hibernating and hindlimb unloading ground squirrels may be different. The present study showed that in femur, the Wnt signaling pathway was inhibited, the protein level of GSK-3ß was increased, and the protein expression of phospho-ß-catenin was decreased in the HIB group as compared with the SA group, which indicates that the Wnt signaling pathway has a great influence on the femur of the HIB group. In conclusion, the natural anti-osteoporosis properties of Daurian ground squirrels are seasonal. The squirrels do not experience bone loss when they are inactive for a long time during hibernation, but the mechanisms of anti-osteoporosis did not work in HLU summer active squirrels.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core , Hibernação , Animais , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , beta Catenina/metabolismo , Sciuridae/fisiologia , Elevação dos Membros Posteriores , Remodelação Óssea , Membro Posterior/fisiologia , Hibernação/fisiologia
3.
Neuroscience ; 514: 67-78, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36738913

RESUMO

The pathophysiological process of neuronal injury due to cerebral ischemia is complex among which disturbance of calcium homeostasis and autophagy are two major pathogenesis. However, it remains ambiguous whether the two factors are independent. Stromal interaction molecule 1 (STIM1) is the most important Ca2+ sensor mediating the store-operated Ca2+ entry (SOCE) through interacting with Orai1 and has recently been proven to participate in autophagy in multiple cells. In this study, we aimed to investigate the potential role of STIM1-induced SOCE on autophagy and whether its regulator function contributes to neuronal injury under hypoxic conditions using in vivo transient middle cerebral artery occlusion (tMCAO) model and in vitro oxygen and glucose deprivation (OGD) primary cultured neuron model respectively. The present data indicated that STIM1 induces autophagic flux impairment in neurons through promoting SOCE and inhibiting AKT/mTOR signaling pathway. Pharmacological inhibition of SOCE or downregulation of STIM1 with siRNA suppressed the autophagic activity in neurons. Moreover, stim1 knockdown attenuated neurological deficits and brain damage after tMCAO, which could be reversed by AKT/mTOR pathway inhibitor AZD5363. Together, the modulation of STIM1 on autophagic activation indicated the potential link between Ca2+ homeostasis and autophagy which provided evidence that STIM1 could be a promising therapeutic target for ischemic stroke.


Assuntos
Cálcio , AVC Isquêmico , Autofagia , Cálcio/metabolismo , Sinalização do Cálcio/fisiologia , Hipocampo/metabolismo , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais
4.
Biomaterials ; 289: 121755, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36049427

RESUMO

Local hypoxia in cellular grafts remains a challenge during the repair of peripheral nerve injury. Oxygen carriers (perfluorotributylamine, PFTBA) have been shown to provide oxygen to Schwann cells (SCs) for a short period. However, the limited oxygen supply from oxygen-carrying materials hinders the ability of such systems to counteract hypoxia over an extended period and limits their therapeutic potential. In this study, PFTBA/VEGF core-shell fibers were fabricated through coaxial electrospinning to construct an oxygen supply system that can sequentially provide oxygen, first via the oxygen carrier and subsequently by promoting angiogenesis via VEGF. Then, the oxygen release and proangiogenic effects of the PFTBA/VEGF core-shell fibers were examined in vitro. Furthermore, sequential oxygen supply conduits prepared using the fibers and filled with SCs were used to bridge 15-mm-long sciatic nerve defects in rats. The PFTBA-VEGF system was confirmed to protect SCs from hypoxia and promote angiogenesis in vitro. Subsequent in vivo studies showed that after the oxygen carried by PFTBA was exhausted, the VEGF could induce neovascularization, and the nascent blood vessels acted as sequential oxygen suppliers for SCs during nerve regeneration. In addition, rats transplanted with the sequential oxygen supply system showed significant morphological and functional improvements in axonal regeneration, the sciatic function index, and the muscle wet weight ratio. The final functional outcomes were similar after treatment with the sequential oxygen supply conduits and autografts. Western blots revealed that the VEGF in the system could upregulate p-AMPK, contributing to axon regeneration after sciatic nerve injury. The sequential oxygen supply system offers essential insights into the oxygen regulation of biomaterials and highlights the potential of oxygen supply strategies as therapeutic approaches for repairing defects in peripheral nerves and other aerobic tissues.


Assuntos
Regeneração Nervosa , Traumatismos dos Nervos Periféricos , Proteínas Quinases Ativadas por AMP/farmacologia , Animais , Axônios , Materiais Biocompatíveis/farmacologia , Hipóxia , Oxigênio/farmacologia , Ratos , Ratos Sprague-Dawley , Células de Schwann/transplante , Nervo Isquiático/fisiologia , Fator A de Crescimento do Endotélio Vascular/farmacologia
5.
Front Med (Lausanne) ; 9: 1067576, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36619638

RESUMO

Background: A substantial heterogeneity exists in patients with upper gastrointestinal submucosal tumors (SMTs). This study aimed to identify predictors of long procedure time (≥60 min), occurrence of procedure-related complications, and long hospital stay (≥6 days) in patients with SMTs undergoing submucosal tunnel endoscopic resection (STER) and stratify risk based on the predictors. Methods: Sixty-six consecutive patients with upper gastrointestinal SMTs undergoing STER between January 2013 and December 2018 were retrospectively included. Binary logistic regression models were developed to identify predictors of outcomes. Receiver operating characteristic (ROC) curves were constructed to evaluate the discrimination of tumor size. Results: Complete resection and en bloc resection of tumor were achieved in 66 (100%) and 64 patients (97%), respectively. Twenty-seven patients (41%) had a long procedure time, 10 (15%) developed STER-related complications, and 17 (26%) had a long hospital stay. On multivariable analysis, tumor size was an independent predictor of long procedure time (OR 1.37, 95% CI 1.13-1.67; p = 0.001), occurrence of complications (OR 1.06, 95% CI 1.01-1.10; p = 0.012), and long hospital stay (OR 1.05, 95% CI 1.01-1.09; p = 0.035). ROC curves identified a tumor of size 25 mm as the best cutoff; those who had a tumor above this value had a 76-fold risk of long procedure time, 8.56-fold risk of occurrence of complications, and 6.35-fold risk of long hospital stay. Conclusion: Patients with a tumor size ≥25 mm had longer procedure time, higher risk of STER-related complications, and longer hospital stay; therefore, they should be classified as a high-risk group.

6.
Front Oncol ; 11: 741403, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737956

RESUMO

The enhancer of zeste homolog 2 (EZH2) is a methylated modification enzyme of Histone H3-Lys 27. The high expression of EZH2 in cells is closely related to the progression, invasion, and metastasis of neoplasm. Therefore, this target is gradually becoming one of the research hot spots of tumor pathogenesis, and the inhibitors of the EZH2 enzyme are expected to become new antitumor drugs. This study used a series of virtual screening technologies to calculate the affinity between the compounds obtained from the ZINC15 database and the target protein EZH2, the stability of the ligand-receptor complex. This experiment also predicted the toxicity and absorption, distribution, metabolism, and excretion (ADME) properties of the candidate drugs in order to obtain compounds with excellent pharmacological properties. Finally, the ligand-receptor complex under in vivo situation was estimated by molecular dynamics simulation to observe whether the complex could exist steadily in the body. The experimental results showed that the two natural compounds ZINC000004217536 and ZINC000003938642 could bind tightly to EZH2, and the ligand-receptor complex could exist stably in vivo. Moreover, these two compounds were calculated to be nontoxic. They also had a high degree of intestinal absorption and high bioavailability. In vitro experiments confirmed that drug ZINC000003938642 could inhibit the proliferation and migration of osteosarcoma, which could serve as potential lead compounds. Therefore, the discovery of these two natural products had broad prospects in the development of EZH2 inhibitors, providing new clues for the treatment or adjuvant treatment of tumors.

7.
Mol Neurobiol ; 58(2): 761-776, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33025508

RESUMO

Nod-like receptor protein 3 (NLRP3)-associated neuroinflammation mediated by activated microglia is involved in the pathogenesis of depression. The role of the pore-forming protein gasdermin D (GSDMD), a newly identified pyroptosis executioner downstream of NLRP3 inflammasome mediating inflammatory programmed cell death, in depression has not been well defined. Here, we provide evidence that paeoniflorin (PF), a monoterpene glycoside compound derived from Paeonia lactiflora, ameliorated reserpine-induced mouse depression-like behaviors, characterized as increased mobility time in tail suspension test and forced swimming test, as well as the abnormal alteration of synaptic plasticity in the depressive hippocampus. The molecular docking simulation predicted that PF would interact with C-terminus of GSDMD. We further demonstrated that PF administration inhibited the enhanced expression of GSDMD which mainly distributed in microglia, along with the proteins involved in pyroptosis signaling transduction including caspase (CASP)-11, CASP-1, NLRP3, and interleukin (IL)-1ß in the hippocampus of mice treated with reserpine. And also, PF prevented lipopolysaccharide (LPS) and adenosine triphosphate (ATP)-induced pyroptosis in murine N9 microglia in vitro, evidenced by inhibiting the expression of CASP-11, NLRP3, CASP-1 cleavage, as well as IL-1ß. Furthermore, VX-765, an effective and selective inhibitor for CASP-1 activation, reduced the expression of inflammasome and pyroptosis-associated proteins in over-activated N9 and also facilitated PF-mediated inhibition of pyroptosis synergistically. Collectively, the data indicated that PF exerted antidepressant effects, alleviating neuroinflammation through inhibiting CASP-11-dependent pyroptosis signaling transduction induced by over-activated microglia in the hippocampus of mice treated with reserpine. Thus, GSDMD-mediated pyroptosis in activated microglia is a previously unrecognized inflammatory mechanism of depression and represents a unique therapeutic opportunity for mitigating depression given PF administration.


Assuntos
Antidepressivos/farmacologia , Caspases Iniciadoras/metabolismo , Glucosídeos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Monoterpenos/farmacologia , Proteínas de Ligação a Fosfato/metabolismo , Piroptose/efeitos dos fármacos , Transdução de Sinais , Trifosfato de Adenosina/farmacologia , Animais , Antidepressivos/química , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Região CA1 Hipocampal/efeitos dos fármacos , Inibidores de Caspase/farmacologia , Linhagem Celular , Espinhas Dendríticas/efeitos dos fármacos , Espinhas Dendríticas/metabolismo , Depressão/tratamento farmacológico , Dipeptídeos/farmacologia , Glucosídeos/administração & dosagem , Glucosídeos/química , Glucosídeos/uso terapêutico , Lipopolissacarídeos/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , Monoterpenos/administração & dosagem , Monoterpenos/química , Monoterpenos/uso terapêutico , Reserpina , Transdução de Sinais/efeitos dos fármacos , para-Aminobenzoatos/farmacologia
8.
ACS Appl Mater Interfaces ; 12(16): 18705-18714, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32216263

RESUMO

This work reports a novel dual-phase glass containing Tm:NaYbF4 upconverting nanocrystals (UCNCs) and CsPbBr3 perovskite nanocrystals (PNCs). The advantages of this kind of nanocomposite are that it provides a solid inorganic glass host for the in situ co-growth of UCNCs and PNCs, and protects PNCs against decomposition affected by the external environment. Tm:NaYbF4 NC-sensitized stable CsPbBr3 PNCs photon UC emission in PNCs is achieved under the irradiation of a 980 nm near-infrared (NIR) laser, and the mechanism is evidenced to be radiative energy transfer (ET) from Tm3+: 1G4 state to PNCs rather than nonradiative Förster resonance ET. Consequently, the decay lifetime of exciton recombination is remarkably lengthened from intrinsic nanoseconds to milliseconds since carriers in PNCs are fed from the long-lifetime Tm3+ intermediate state. Under the simultaneous excitation of the ultraviolet (UV) light and NIR laser, dual-modal photon UC and downshifting (DS) emissions from ultra-stable CsPbBr3 PNCs in the glass are observed, and the combined UC/DS emitting color can be easily altered by modifying the pumping light power. In addition, UC exciton recombination and Tm3+ 4f-4f transitions are found to be highly temperature sensitive. All these unique emissive features enable the practical applications of the developed dual-phase glass in advanced anti-counterfeit and accurate temperature detection.

9.
Nanoscale ; 11(37): 17216-17221, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31531444

RESUMO

In the last few years, all-inorganic cesium lead halide (CsPbX3) quantum dots have shown unprecedented radical progress for practical applications in the optoelectronic field, but they quickly decompose when exposed to air. The in situ growth of the CsPbX3 particles inside amorphous glass can significantly improve their stability. Unfortunately, it is formidably difficult to precipitate whole-family CsPbX3 from a glass matrix and their photoluminescence quantum yields require further improvement. Herein, fluoride additives were introduced into oxyhalide borosilicate glasses to break the tight glass network, which promoted the nucleation/growth of CsPbX3 (X = Cl, Cl/Br, Br, Br/I and I) inside the glass. Importantly, the quantum efficiencies of glass-stabilized CsPbBr3, CsPb(Br/I)3 and CsPbI3 reached 80%, 60% and 50%, respectively, which are the highest efficiencies reported so far. Benefiting from the effective protection of robust glass, CsPbX3 quantum dots exhibited superior water resistance with more than 90% luminescence remaining after immersing them in water for 30 days, and halogen anion exchange among different CsPbX3 materials was completely inhibited. Two prototype light-emitting diodes were constructed by coupling green/red and green/orange/red quantum dots with InGaN blue chips, yielding bright white light with optimal luminous efficiency of 93 lm W-1, tunable color temperature of 2000-5800 K and high color rendering index of 90.

10.
Physiol Res ; 66(4): 567-580, 2017 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-28406700

RESUMO

Numerous countermeasures have been proposed to minimize microgravity-induced physical deconditioning, but their benefits are limited. The present study aimed to investigate whether personalized aerobic exercise based on artificial gravity (AG) mitigates multisystem physical deconditioning. Fourteen men were assigned to the control group (n=6) and the countermeasure group (CM, n=8). Subjects in the CM group were exposed to AG (2 Gz at foot level) for 30 min twice daily, during which time cycling exercise of 80-95 % anaerobic threshold (AT) intensity was undertaken. Orthostatic tolerance (OT), exercise tests, and blood assays were determined before and after 4 days head-down bed rest (HDBR). Cardiac systolic function was measured every day. After HDBR, OT decreased to 50.9 % and 77.5 % of pre-HDBR values in control and CM groups, respectively. Exercise endurance, maximal oxygen consumption, and AT decreased to 96.5 %, 91.5 % and 91.8 % of pre-HDBR values, respectively, in the control group. Nevertheless, there were slight changes in the CM group. HDBR increased heart rate, sympathetic activity, and the pre-ejection period, but decreased plasma volume, parasympathetic activity and left-ventricular ejection time in the control group, whereas these effects were eliminated in the CM group. Aldosterone had no change in the control group but increased significantly in the CM group. Our study shows that 80-95 % AT aerobic exercise based on 2 Gz of AG preserves OT and exercise endurance, and affects body fluid regulation during short-term HDBR. The underlying mechanisms might involve maintained cardiac systolic function, preserved plasma volume, and improved sympathetic responses to orthostatic stress.


Assuntos
Repouso em Cama/métodos , Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Gravidade Alterada , Decúbito Inclinado com Rebaixamento da Cabeça/fisiologia , Frequência Cardíaca/fisiologia , Adulto , Humanos , Masculino , Intolerância Ortostática/diagnóstico , Intolerância Ortostática/fisiopatologia , Consumo de Oxigênio/fisiologia , Fatores de Tempo , Simulação de Ausência de Peso/métodos , Adulto Jovem
11.
Cell Physiol Biochem ; 41(1): 227-238, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28214845

RESUMO

BACKGROUND/AIMS: Microgravity leads to hydrodynamic alterations in the cardiovascular system and is associated with increased angiogenesis, an important aspect of endothelial cell behavior to initiate new vessel growth. Given the critical role of Rho GTPase-dependent cytoskeleton rearrangement in cell migration, small GTPase RhoA might play a potential role in microgravity-induced angiogenesis. METHODS: We examined the organization of actin filaments by FITC-conjugated phalloidin staining, as well as the expression and activity of RhoA by quantitative PCR and Western blot, in human umbilical vein endothelial cells (HUVECs) under normal gravity and simulated microgravity. Effect of simulated microgravity on the wound closure and tube formation in HUVECs, and their dependence on RhoA, were also analyzed by cell migration and tube formation assays. RESULTS: We show that in HUVECs actin filaments are disorganized and RhoA activity is reduced by simulated microgravity. Blocking RhoA activity either by C3 transferase Rho inhibitor or siRNA knockdown mimicked the effect of simulated microgravity on inducing actin filament disassembly, followed by enhanced wound closure and tube formation in HUVECs, which closely resembled effects seen on microgravity-treated cells. In contrast, overexpressing RhoA in microgravity-treated HUVECs restored the actin filaments, and decreased wound closure and tube formation abilities. CONCLUSION: These results suggest that RhoA inactivation is involved in the actin rearrangement-associated angiogenic responses in HUVECs during simulated microgravity.


Assuntos
Citoesqueleto de Actina/fisiologia , Actinas/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Neovascularização Fisiológica/fisiologia , Proteína rhoA de Ligação ao GTP/metabolismo , Movimento Celular , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Microscopia de Fluorescência , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Simulação de Ausência de Peso , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/genética
12.
Oncol Lett ; 11(5): 3303-3307, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27123107

RESUMO

Gastrointestinal stromal tumors (GIST) are mesenchymal neoplasms of the gastrointestinal tract (GI) that are defined, in part, by the expression of CD117, a c-Kit proto-oncogene protein. GISTs emerge outside of the GI at a very low frequency, typically in a single organ or location. GISTs that occasionally emerge outside of the GI are classified as extra-gastrointestinal stromal tumors (EGIST). The present study reports an extremely rare case of EGIST detected in the pancreas and the liver. The pancreatic and liver tumors were 4.5×2.5 cm and 2.0×1.5 cm in size, respectively. Both tumors consisted of CD117-positive spindle cells with a similar mitotic rate of 1-2 per 50 high power fields. The pancreatic and the hepatic EGISTs were at a low risk of malignancy, and both tumors were proposed to be primary stromal tumors. To the best of our knowledge, this is the first report of likely primary EGIST identified in the pancreas and liver of the same patient.

13.
Cell Physiol Biochem ; 38(2): 502-13, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26828798

RESUMO

BACKGROUND/AIMS: The potential role of caveolin-1 in modulating angiogenesis in microgravity environment is unexplored. METHODS: Using simulated microgravity by clinostat, we measured the expressions and interactions of caveolin-1 and eNOS in human umbilical vein endothelial cells. RESULTS: We found that decreased caveolin-1 expression is associated with increased expression and phosphorylation levels of eNOS in endothelial cells stimulated by microgravity, which causes a dissociation of eNOS from caveolin-1 complexes. As a result, microgravity induces cell migration and tube formation in endothelial cell in vitro that depends on the regulations of caveolin-1. CONCLUSION: Our study provides insight for the important endothelial functions in altered gravitational environments.


Assuntos
Cavéolas/metabolismo , Caveolina 1/metabolismo , Neovascularização Fisiológica , Óxido Nítrico Sintase Tipo III/metabolismo , Simulação de Ausência de Peso , Caveolina 1/análise , Movimento Celular , Células Endoteliais da Veia Umbilical Humana , Humanos , Óxido Nítrico Sintase Tipo III/análise , Mapas de Interação de Proteínas
14.
Acupunct Med ; 33(5): 381-7, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26025383

RESUMO

OBJECTIVE: Spaceflight is associated with cardiovascular deregulation. However, the influence of microgravity on the cardiovascular system and its mechanisms and countermeasures remain unknown. Our previous studies have demonstrated that transcutaneous electrical acupuncture stimulation (TEAS) is effective in improving orthostatic tolerance (OT). The purpose of this study was to determine if TEAS treatment can attenuate cardiovascular deconditioning induced by a 4-day -6° head-down bed rest (HDBR). METHODS: Fourteen healthy male subjects were randomly allocated to a control group (control, n=6, 4 days HDBR without countermeasures) and a TEAS treatment group (TEAS, n=8, 4 days HDBR with TEAS at Neiguan (PC6) for 30 min each day for 4 consecutive days during HDBR). OT, plasma hormones, plasma volume and heart rate variability were assessed before and after HDBR. Cardiac function and cerebral blood flow were measured before, during and after HDBR. RESULTS: The data showed that TEAS treatment mitigated the decrease in OT that was observed in the control group and cardiac function, alleviated autonomic dysfunction, and partially prevented plasma volume reduction after HDBR. Angiotensin II and aldosterone were significantly increased by 129.3% and 133.3% after HDBR in the TEAS group (p<0.05). CONCLUSIONS: These results indicate that 30 min of daily TEAS treatment at PC6 is partially effective in maintaining OT, probably due to increased plasma volume-regulating hormones and activation of the peripheral sympathetic nervous system. TEAS treatment appears effective at reducing cardiovascular deconditioning induced by HDBR for 4 days. TRIAL REGISTRATION NUMBER: NCT02300207.


Assuntos
Repouso em Cama , Descondicionamento Cardiovascular , Eletroacupuntura , Decúbito Inclinado com Rebaixamento da Cabeça , Adulto , Pressão Sanguínea , Circulação Cerebrovascular , Frequência Cardíaca , Hormônios/sangue , Humanos , Masculino , Intolerância Ortostática , Adulto Jovem
15.
J Appl Physiol (1985) ; 118(11): 1356-63, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-25749443

RESUMO

The hypothesis that cerebrovascular autoregulation was not impaired during head-up tilt (HUT) that followed brief exposures to varying degrees of prior head-down tilt (HDT) was tested in 10 healthy young men and women. Cerebral mean flow velocity (MFV) and cardiovascular responses were measured in transitions to a 60-s period of 75° HUT that followed supine rest (control) or 15 s HDT at -10°, -25°, and -55°. During HDT, heart rate (HR) was reduced for -25° and -55°, and cardiac output was lower at -55° HDT. MFV increased during -10° HDT, but not in the other conditions even though blood pressure at the middle cerebral artery (BPMCA) increased. On the transition to HUT, HR increased only for -55° condition, but stroke volume and cardiac output transiently increased for -25° and -55°. Total peripheral resistance index decreased in proportion to the magnitude of HDT and recovered over the first 20 s of HUT. MFV was significantly less in all HDT conditions compared with the control in the first 5-s period of HUT, but it recovered quickly. An autoregulation correction index derived from MFV recovery relative to BPMCA decline revealed a delay in the first 5 s for prior HDT compared with control but then a rapid increase to briefly exceed control after -55° HDT. This study showed that cerebrovascular autoregulation is modified by but not impaired by brief HDT prior to HUT and that cerebral MFV recovered quickly and more rapidly than arterial blood pressure to protect against cerebral hypoperfusion and potential syncope.


Assuntos
Circulação Cerebrovascular , Decúbito Inclinado com Rebaixamento da Cabeça , Hemodinâmica , Artéria Cerebral Média/fisiologia , Postura , Teste da Mesa Inclinada , Adaptação Fisiológica , Adulto , Pressão Arterial , Velocidade do Fluxo Sanguíneo , Feminino , Frequência Cardíaca , Homeostase , Humanos , Masculino , Artéria Cerebral Média/diagnóstico por imagem , Distribuição Aleatória , Fluxo Sanguíneo Regional , Volume Sistólico , Fatores de Tempo , Ultrassonografia Doppler Transcraniana , Resistência Vascular
16.
Mol Med Rep ; 12(1): 449-55, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25683634

RESUMO

B-cell lymphoma-extra large (Bcl-xL), an important member of anti-apoptotic Bcl-2 family, is involved in tumor progression and development. The overexpression of Bcl-xL is associated with radioresistance of human malignancies. The present study aimed to investigate the inhibitory effect of small interfering RNA (siRNA) on the expression of Bcl-xL in the A549 non-small lung cancer (NSCLC) cell line, and its role in inducing the apoptosis and increasing the radiosensitivity of A549 cells. An siRNA expression vector, pSilencer4-CMVneo-short hairpin (sh)RNA, was constructed and stably transfected into A549 cells. The effects of Bcl-xL-shRNA on cell proliferation, apoptosis and the protein expression levels of associated proteins were assessed in vitro in the A549 cells. The radiosensitivity of the A549 cells was evaluated using a clonogenic cell survival assay. The results demonstrated that the sequence-specific siRNA targeting Bcl-xL efficiently and specifically downregulated the mRNA and protein expression levels of Bcl-xL. The RNA interference-mediated downregulation in the expression of Bcl-xL inhibited cell proliferation, induced apoptosis and reduced the radioresistance of the NSCLC cells. These findings suggested that Bcl-xL may be a promising therapeutic approach for the treatment of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Tolerância a Radiação/genética , Proteína bcl-X/biossíntese , Apoptose/genética , Apoptose/efeitos da radiação , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Regulação Neoplásica da Expressão Gênica , Humanos , Interferência de RNA , RNA Mensageiro/biossíntese , Proteína bcl-X/genética
17.
Oncol Lett ; 8(6): 2806-2810, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25364470

RESUMO

Although cisplatin (DDP) has been reported to be a promising antitumor therapy for non-small cell lung cancer (NSCLC), the effectiveness of the treatment remains limited due to an inherent tumor resistance to DDP. Genistein (GEN) is an abundant, naturally occurring isoflavonoid found in soy products that has been demonstrated to increase the anti-neoplastic activity of certain chemotherapy drugs in multiple tumor types. In the present study, DDP in combination with GEN was selected as a potential treatment to suppress tumor growth and simultaneously reduce the doses of the two drugs required for the treatment of NSCLC. Cell growth inhibition, apoptosis, cell cycle distribution and receptor signaling assays were conducted. In the in vivo study, DDP and GEN, either alone or in combination, were used to treat a xenograft model of the A549 cells. It was found that the combination of low concentrations of DDP and GEN induced significantly greater growth inhibition (P<0.01) and increased apoptosis in the A549 cells compared with either agent alone. In addition, DDP in combination with GEN could significantly suppress tumor growth in vivo compared with either agent alone. Combination treatment significantly suppresses constitutive phosphorylation of AKT and phosphoinositide-3 kinase, which may contribute to the inhibition of tumor growth. Overall, the present data suggested that GEN can increase the anti-neoplastic activity of DDP and that a combination of GEN and DDP is a potential drug candidate for the treatment of NSCLC.

18.
Biochem Cell Biol ; 91(5): 309-14, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24032680

RESUMO

Individuals exposed to extended periods of spaceflight or prolonged 6° head-down-tilt bed rest often suffer from health hazards represented by cardiovascular deconditioning. Many studies have reported that alterations in vascular endothelial cells contribute to cardiovascular dysfunction induced by microgravity. Autophagy, a lysosomal degradation pathway, serves an adaptive role for survival, differentiation, and development in cellular homeostasis, and can be triggered by various environmental stimuli. However, whether autophagy can be induced in endothelial cells by real or simulated microgravity remains to be determined. This study was designed to investigate the effects of simulated microgravity on the activation of autophagy in human umbilical vein endothelial cells (HUVECs). We report here that clinorotation, a simulated model of microgravity, enhances autophagosome formation, increases LC3 and beclin-1 expression, and promotes the conversion of LC3-I to LC3-II in HUVECs. These results demonstrate that simulated microgravity for 48 h activates autophagy of vascular endothelial cells.


Assuntos
Autofagia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Rotação/efeitos adversos , Ausência de Peso/efeitos adversos , Proteínas Reguladoras de Apoptose/biossíntese , Proteína Beclina-1 , Descondicionamento Cardiovascular/fisiologia , Linhagem Celular , Humanos , Proteínas de Membrana/biossíntese , Proteínas Associadas aos Microtúbulos/biossíntese , Proteínas Associadas aos Microtúbulos/metabolismo , Voo Espacial
19.
Clin Physiol Funct Imaging ; 33(1): 24-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23216762

RESUMO

There is evidence to suggest that microgravity/weightlessness can induce changes in lung physiology/function. We hypothesized that microgravity, induced by head-down bed rest (HDBR), would induce changes in lung function and that exercise training with artificial gravity (AG) would prevent these changes from occurring. Twelve participants were randomly assigned to a control or AG exercise countermeasure (CM) group (n = 6 per group) and 96 h of 6° HDBR. Participants in the CM group were exposed to AG (alternating 2 min intervals of +1·0 and +2·0 G) for 30 min, twice daily, during which time ergometric exercise (40 W intensity) was performed. Pulse rate, oxygen saturation (SO(2) ) and lung function were measured and compared between groups. The CM and control groups were similar in mean age, height and weight. There were no significant within or between group differences over time in pulse rate, SO(2) , vital capacity, inspiratory capacity, tidal volume, expiratory reserve volume, inspiratory reserve volume, minute ventilation, forced vital capacity, forced expiratory volume in 1 s, peak expiratory flow, maximal expiratory flow in 25%, 50% and 75% vital capacity, forced inspiratory vital capacity, forced inspiratory volume in 1 s and maximal voluntary ventilation. Microgravity induced by 96 h of HDBR does not appear to affect lung function in humans. Further, AG with exercise training does not change lung function during 96 h of HDBR in humans.


Assuntos
Repouso em Cama , Exercício Físico , Gravidade Alterada , Decúbito Inclinado com Rebaixamento da Cabeça , Pulmão/fisiologia , Ventilação Pulmonar , Respiração , Simulação de Ausência de Peso , Adaptação Fisiológica , China , Humanos , Masculino , Análise Multivariada , Testes de Função Respiratória , Fatores de Tempo , Adulto Jovem
20.
Europace ; 15(1): 127-34, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22791300

RESUMO

AIMS: Orthostatic intolerance (OI) is a common clinical problem; however, effective and applicable clinical prevention/treatment is limited. The aim of this study was to investigate whether electroacupuncture (EA) is a novel effective treatment in attenuating OI in healthy individuals. METHODS AND RESULTS: This study used a randomized, controlled, crossover design using two protocols. Orthostatic intolerance was induced with a combination of head-up tilt (HUT) and lower body negative pressure (LBNP). Twenty healthy individuals in Protocol 1 and 10 healthy individuals in Protocol 2 received no EA, EA at PC-6 acupuncture points (acupoint), and EA at a non-acupoint in a random order with an interim of 1 week. Electroacupuncture was administered prior to HUT/LBNP in Protocol 1 and simultaneously during HUT/LBNP in Protocol 2. Electroacupuncture at PC-6 administered either before or during HUT/LBNP postponed the occurrence of pre-syncopal symptoms, improved haemodynamic responses to HUT/LBNP (including increased diastolic blood pressure, stroke volume, and total peripheral resistance and a decreased heart rate), blunted decreases of maximum velocity and velocity time integral of blood flow in the middle cerebral artery, and increased plasma noradrenalin and adrenalin concentrations. In addition, heart rate variability analysis revealed that EA at PC-6 either before or during HUT/LBNP decreased high-frequency ranges of R-R interval while increasing low-frequency ranges of R-R interval, which indicates an elevated heart sympathetic tone. CONCLUSION: Electroacupuncture at PC-6 is effective in improving orthostatic tolerance. Cardiac function improvement and sympathetic activation are responsible for the improved orthostatic tolerance after EA. EA represents a novel intervention against OI.


Assuntos
Eletroacupuntura/métodos , Intolerância Ortostática/fisiopatologia , Intolerância Ortostática/reabilitação , Sistema Nervoso Simpático/fisiopatologia , Disfunção Ventricular Esquerda/prevenção & controle , Disfunção Ventricular Esquerda/fisiopatologia , Feminino , Humanos , Masculino , Intolerância Ortostática/complicações , Valores de Referência , Resultado do Tratamento , Disfunção Ventricular Esquerda/etiologia , Adulto Jovem
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