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1.
Molecules ; 28(3)2023 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-36770781

RESUMO

Breast cancer is one of the most prevalent malignancies and the leading cause of cancer-associated mortality in China. Icaritin (ICT), a prenyl flavonoid derived from the Epimedium Genus, has been proven to inhibit the proliferation and stemness of breast cancer cells. Our previous study demonstrated that IC2, a derivative of ICT, could induce breast cancer cell apoptosis by Stearoyl-CoA desaturase 1 (SCD1) inhibition. The present study further investigated the mechanism of the inhibitory effects of IC2 on breast cancer cells in vitro and in vivo. Our results proved that IC2 could stimulate autophagy in breast cancer cells with the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling and mitogen-activated protein kinase (MAPK) signaling. Combination treatment of the AMPK inhibitor decreased IC2-induced autophagy while it markedly enhanced IC2-induced apoptosis. In common with IC2-induced apoptosis, SCD1 overexpression or the addition of exogenous oleic acid (OA) could also alleviate IC2-induced autophagy. In vivo assays additionally demonstrated that IC2 treatment markedly inhibited tumor growth in a mouse breast cancer xenograft model. Overall, our study was the first to demonstrate that IC2 induced cytoprotective autophagy by SCD1 inhibition in breast cancer cells and that the autophagy inhibitor markedly enhanced the anticancer activity of IC2. Therefore, IC2 was a potential candidate compound in combination therapy for breast cancer.


Assuntos
Proteínas Quinases Ativadas por AMP , Neoplasias da Mama , Humanos , Animais , Camundongos , Feminino , Proteínas Quinases Ativadas por AMP/metabolismo , Apoptose , Flavonoides/farmacologia , Neoplasias da Mama/metabolismo , Autofagia , Linhagem Celular Tumoral , Estearoil-CoA Dessaturase/genética
2.
Cancer Cell Int ; 22(1): 202, 2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35642041

RESUMO

BACKGROUND: Breast cancer is the most common malignancy affecting women, yet effective targets and related candidate compounds for breast cancer treatment are still lacking. The lipogenic enzyme, stearoyl-CoA desaturase-1 (SCD1), has been considered a potential target for breast cancer treatment. Icaritin (ICT), a prenylflavonoid derivative from the Traditional Chinese Medicine Epimedii Herba, has been reported to exert anticancer effects in various types of cancer. The purpose of the present study was to explore the effect of the new ICT derivative, IC2, targeting SCD1 on breast cancer cells and to explore the specific mechanism. METHODS: Immunohistochemistry and semiquantitative evaluation were performed to detect the expression level of SCD1 in normal and tumor samples. Computer-aided drug design (CADD) technology was used to target SCD1 by molecular docking simulation, and several new ICT derivatives were prepared by conventional chemical synthesis. Cell viability was evaluated by an MTT assay and dead cell staining. SCD1 expression in cancer cells was determined by Western blot and qRT-PCR analyses. The enzymatic activity of SCD1 was evaluated by detecting the conversion rate of [d31] palmitic acid (PA) using Gas chromatography-mass spectrometry (GC-MS). DAPI staining, flow cytometry and Western blot were used to detect cell apoptosis. Mitochondrial membrane potential and reactive oxygen species (ROS) assays were used to determine cell mitochondrial function. Lentiviral transduction was utilized to generate SCD1-overexpressing cell lines. RESULTS: We found that SCD1 was overexpressed and correlated with poor prognosis in breast cancer patients. Among a series of ICT derivatives, in vitro data showed that IC2 potentially inhibited the viability of breast cancer cells, and the mechanistic study revealed that IC2 treatment resulted in ROS activation and cellular apoptosis. We demonstrated that IC2 inhibited SCD1 activity and expression in breast cancer cells in a dose-dependent manner. Moreover, SCD1 overexpression alleviated IC2-induced cytotoxicity and apoptosis in breast cancer cells. CONCLUSIONS: The new ICT derivative, IC2, was developed to induce breast cancer cell apoptosis by inhibiting SCD1, which provides a basis for the development of IC2 as a potential clinical compound for breast cancer treatment.

3.
Appl Opt ; 61(18): 5368-5374, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-36256102

RESUMO

In this work, a resource management algorithm is proposed for an indoor visible light communication (VLC) access network using an orthogonal frequency division multiple access (OFDMA) scheme. With OFDMA, adaptive modulation is adopted to improve the frequency spectrum efficiency of this VLC system. Specifically, the long-term time-averaged optimization problem is transformed into a series of single timeslot online problems via a Lyapunov optimization technique. Then, each user is provided with a separate queue to maintain the random arrival data by a VLC access point, and a subcarrier allocation solution is subsequently presented to maximize the transmission rate. Numerical simulation shows that compared with the best channel state information (BC) algorithm and round robin (RR) algorithm, the proposed algorithm can not only ensure the transmission rate but also greatly improve system stability. In particular, for mean arrival rate B=7Kbits/timeslot, the system stability by the proposed algorithm improves by about 53.36% and 61.36% in comparison with BC and RR algorithms, respectively. This work will benefit the design and development of indoor OFDMA VLC systems.

4.
Opt Express ; 29(21): 32778-32795, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34809101

RESUMO

In this work, a dynamic resource allocation (DRA) algorithm is proposed to optimize the transmission rate subject to the access point assignment, bandwidth and transmit power allocation in RF/VLC heterogeneous networks, which combines the visible light communication (VLC) access point (AP) and radio frequency (RF) AP. To optimize the allocation among resource block (RB), subchannel and power, the time-average transmission rate is maximized under time-average transmit power budget. Specifically, the time-average optimization problem is converted into series of single timeslot online problem by Lyapunov optimization technique. Because of its complexity and non-convexity, the problem is decomposed into three independent subproblems for which a non-iterative solution is presented on the basis of Lagrange relaxation and convex optimization theory. Numerical simulations are conducted to demonstrate the effectiveness of the proposed DRA algorithm. And the comparisons with two classical algorithms are also given in terms of transmission rate and system stability. This work will benefit the design and development of hybrid RF/VLC system.

5.
FASEB J ; 34(10): 14042-14054, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32910484

RESUMO

Diabetes mellitus (DM) patients are at a higher risk of developing brain injury characterized by neuronal death. Melatonin, a hormone produced by the pineal gland, exerts neuroprotective effects against brain damage. However, the effect of melatonin on diabetes-induced brain injury has not been elucidated. This study was to evaluate the role of melatonin against neuronal death in DM and to elucidate the underlying mechanisms. Herein, we found that melatonin administration significantly alleviated the neuronal death in both streptozotocin (STZ)-induced diabetic mice and high glucose (HG)-treated neuronal cells. Melatonin inhibited neuronal pyroptosis and excessive autophagy, as evidenced by decreased levels of NLRP3, cleaved caspase-1, GSDMD-N, IL-1ß, LC3, Beclin1, and ATG12 both in vivo and in vitro. MicroRNA-214-3p (miR-214-3p) was decreased in DM mice and HG-treated cells, and such a downregulation was corrected by melatonin, which was accompanied by repression of caspase-1 and ATG12. Furthermore, downregulation of miR-214-3p abrogated the anti-pyroptotic and anti-autophagic actions of melatonin in vitro. Our results indicate that melatonin exhibits a neuroprotective effect by inhibiting neuronal pyroptosis and excessive autophagy through modulating the miR-214-3p/caspase-1 and miR-214-3p/ATG12 axes, respectively, and it might be a potential agent for the treatment of brain damage in the setting of DM.


Assuntos
Autofagia , Neuropatias Diabéticas/tratamento farmacológico , Melatonina/uso terapêutico , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Piroptose , Animais , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Proteína 12 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Caspase 1/metabolismo , Linhagem Celular , Diabetes Mellitus Experimental/tratamento farmacológico , Humanos , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Melatonina/farmacologia , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Proteínas de Ligação a Fosfato/metabolismo
6.
FASEB J ; 34(4): 5282-5298, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32067273

RESUMO

Melatonin is a hormone produced by the pineal gland, and it has extensive beneficial effects on various tissue and organs; however, whether melatonin has any effect on cardiac fibrosis in the pathogenesis of diabetic cardiomyopathy (DCM) is still unknown. Herein, we found that melatonin administration significantly ameliorated cardiac dysfunction and reduced collagen production by inhibiting TGF-ß1/Smads signaling and NLRP3 inflammasome activation, as manifested by downregulating the expression of TGF-ß1, p-Smad2, p-Smad3, NLRP3, ASC, cleaved caspase-1, mature IL-1ß, and IL-18 in the heart of melatonin-treated mice with diabetes mellitus (DM). Similar beneficial effects of melatonin were consistently observed in high glucose (HG)-treated cardiac fibroblasts (CFs). Moreover, we also found that lncRNA MALAT1 (lncR-MALAT1) was increased along with concomitant decrease in microRNA-141 (miR-141) in DM mice and HG-treated CFs. Furthermore, we established NLRP3 and TGF-ß1 as target genes of miR-141 and lncR-MALAT1 as an endogenous sponge or ceRNA to limit the functional availability of miR-141. Finally, we observed that knockdown of miR-141 abrogated anti-fibrosis action of melatonin in HG-treated CFs. Our findings indicate that melatonin produces an antifibrotic effect via inhibiting lncR-MALAT1/miR-141-mediated NLRP3 inflammasome activation and TGF-ß1/Smads signaling, and it might be considered a potential agent for the treatment of DCM.


Assuntos
Diabetes Mellitus Experimental/complicações , Cardiomiopatias Diabéticas/patologia , Fibrose/tratamento farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Cardiopatias/tratamento farmacológico , Melatonina/farmacologia , Animais , Antioxidantes/farmacologia , Cardiomiopatias Diabéticas/epidemiologia , Fibrose/etiologia , Fibrose/metabolismo , Fibrose/patologia , Cardiopatias/etiologia , Cardiopatias/metabolismo , Cardiopatias/patologia , Inflamassomos/antagonistas & inibidores , Inflamassomos/genética , Inflamassomos/metabolismo , Masculino , Camundongos , MicroRNAs/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , RNA Longo não Codificante/genética , Proteínas Smad/antagonistas & inibidores , Proteínas Smad/genética , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/antagonistas & inibidores , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
7.
Appl Opt ; 60(26): 8031-8037, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34613064

RESUMO

In this work, an angle diversity receiver (ADR) structure is proposed to optimize the uniformity of the received optical power distribution in an indoor visible light communication (VLC) system. Taking the rectangular and hybrid layouts with 16 light-emitting diodes as examples, different inclination angles and the number of side detectors are investigated with three diversity combining techniques in a typical room, where the primary reflection of the wall is considered. Simulation results showed that the inclination angles and the number of side detectors would affect the variance and average of the received optical power, and the variance would decrease with the increase of the number of side detectors. In addition, maximal ratio combining is more suitable for the ADR when the variance and average of the received optical power are considered simultaneously. By applying the ADR with five side detectors, the variances of the received optical power will decrease by 81.34% and 86.09% under the rectangle layout and the hybrid layout, respectively. This work will benefit the design and development of the VLC system.

8.
J Cell Mol Med ; 24(16): 8950-8961, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32583517

RESUMO

The transcriptional repressor Bmi-1 is involved in cell-cycle regulation and cell senescence, the deficiency of which has been shown to cause oxidative stress. This study investigated whether Bmi-1 deficiency plays a role in promoting disc degeneration and the effect of treatment with antioxidant N-acetylcysteine (NAC) on intervertebral disc degeneration. Bmi-1-/- mice were treated with the antioxidant NAC, supplied in drinking water (Bmi-1-/- +NAC). For in vitro experiments, mouse intervertebral discs were cultured under low oxygen tension and serum-limiting conditions in the presence of tumour necrosis factor α and interleukin 1ß in order to mimic degenerative insult. Disc metabolism parameters in these in vitro and in vivo studies were evaluated by histopathological, immunohistochemical and molecular methods. Bmi-1-/- mice showed lower collagen Ⅱ and aggrecan levels and higher collagen Ⅹ levels than wild-type and Bmi-1-/- +NAC mice. Bmi-1-/- mice showed significantly lower superoxide dismutase (SOD)-1, SOD-2, glutathione peroxidase (GPX)-1 and GPX-3 levels than their wild-type littermates and Bmi-1-/- + NAC mice. Relative to Bmi-1-/- mice, the control and Bmi-1-/- +NAC mice showed significantly lower p16, p21, and p53 levels. These results demonstrate that Bmi-1 plays an important role in attenuating intervertebral disc degeneration in mice by inhibiting oxidative stress and cell apoptosis.


Assuntos
Antioxidantes/fisiologia , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Complexo Repressor Polycomb 1/deficiência , Proteínas Proto-Oncogênicas/deficiência , Acetilcisteína/farmacologia , Agrecanas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Colágeno/metabolismo , Interleucina-1beta/metabolismo , Disco Intervertebral/efeitos dos fármacos , Disco Intervertebral/metabolismo , Camundongos , Técnicas de Cultura de Órgãos/métodos , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
J Cell Physiol ; 235(11): 7769-7779, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-31710102

RESUMO

Hyperglycemia-induced cardiac fibrosis is a prominent characteristic of diabetic cardiomyopathy. Changes in proinflammatory cytokines have been shown to lead to cardiac fibrosis in patients with diabetes mellitus. This study aimed to investigate the role of miR-150-5p in mediating cardiac inflammation and fibrosis in cardiac fibroblasts (CFs). Herein, we found that high-glucose (HG) treatment significantly induced cardiac inflammation, as manifested by increased proinflammatory cytokine production (IL-1ß) and NF-κB activity in CFs. Moreover, HG markedly aggravated cardiac fibrosis and increased levels of fibrotic markers (CTGF, FN, α-SMA) and extracellular matrix proteins (Col-I, Col-III) in CFs. At the same time, HG disturbed the TGF-ß1/Smad signaling pathway, as evidenced by increases in TGF-ß1 and p-Smad2/3 levels and decreases in Smad7 levels in CFs. Furthermore, we found that miR-150-5p was upregulated by HG, which negatively regulated Smad7 expression at the posttranscription level. Further study demonstrated that cardiac inflammation and fibrosis in CFs were corrected following miR-150-5p knockdown, but exacerbated by miR-150-5p overexpression. These data indicated that miR-150-5p inhibition could ameliorate NF-κB-related inflammation and TGF-ß1/Smad-induced cardiac fibrosis through targeting Smad7. Thus, miR-150-5p may be a novel promising target for treating diabetic cardiomyopathy.


Assuntos
Cardiomiopatias Diabéticas/metabolismo , Fibroblastos/patologia , Glucose/toxicidade , MicroRNAs/metabolismo , Proteína Smad7/metabolismo , Animais , Células Cultivadas , Cardiomiopatias Diabéticas/patologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibrose , Regulação da Expressão Gênica , Hiperglicemia/metabolismo , Hiperglicemia/patologia , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
10.
Appl Opt ; 59(34): 10638-10644, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33361880

RESUMO

Aiming at the problem of uneven distribution of receiving illuminance and optical power on the receiving plane of the visible light communication (VLC) system, this paper proposes a light source optimization method based on an improved bat algorithm (IBA). Taking the rectangular and hybrid layouts with 16 light-emitting diodes (LEDs), as examples, we set the variance of received light power on the receiving plane as the fitness function. By redesigning the speed update method and local search method of the traditional bat algorithm (BA), the IBA is used to optimize the LED half-power angle and LED position that affect the system performance. The simulation results show that, considering the primary reflection of the wall, the method can reduce the received illumination and optical power fluctuation of the receiving plane within a limited number of iterations under different light source layout schemes.

11.
Gynecol Endocrinol ; 36(3): 218-221, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31650878

RESUMO

Kallmann syndrome (KS) is a rare inherited disorder, which has significantly genotypic and phenotypic heterogeneity. KS is clinically characterized by the combination of hypogonadotropic hypogonadism and hypo/anosmia. At present, there is no relevant report that intron mutation in SEMA7A gene helps induce KS. A 17-year-old Chinese female (46, XX) came to our department due to primary amenorrhea, who actually had hyposmia since her childhood. Hypogonadotropic hypogonadism was then detected. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels were remarkably low. And estradiol level was extremely low. The laboratory test results were consistent with KS. A heterozygous point mutation of intron 13 in SEMA7A (NM_003612.3:c.1640-3C > A) was identified. The patient received the treatment of pulsatile gonadotropin-releasing hormone (GnRH) pump, which could imitate physiological ovarian stimulation, thus resulting in mature follicle and a peak of LH. The patient was injected subcutaneously every 90 min with a dose of 10 µg per pulse, which had bona efficacy. She acquired menarche at about 43 days after the treatment. We firstly report a case of KS caused by a novel mutation site in the intron of SEMA7A gene. We mainly provide insight into the clinical manifestations, genetic diagnosis and treatment of KS.


Assuntos
Antígenos CD/genética , Síndrome de Kallmann/genética , Semaforinas/genética , Adolescente , Amenorreia/etiologia , Anosmia/etiologia , Pai , Feminino , Hormônio Foliculoestimulante/sangue , Proteínas Ligadas por GPI/genética , Hormônio Liberador de Gonadotropina/uso terapêutico , Heterozigoto , Humanos , Íntrons , Síndrome de Kallmann/complicações , Síndrome de Kallmann/diagnóstico , Síndrome de Kallmann/tratamento farmacológico , Hormônio Luteinizante/sangue , Imageamento por Ressonância Magnética , Mutação , Bulbo Olfatório/diagnóstico por imagem , Bulbo Olfatório/patologia , Tamanho do Órgão , Hipófise/diagnóstico por imagem , Hipófise/patologia , Pulsoterapia , Sequenciamento do Exoma
12.
Acta Biochim Biophys Sin (Shanghai) ; 52(10): 1111-1119, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33085741

RESUMO

MicroRNAs (miRNAs) play an important role in cardiac function and metabolism. However, whether they regulate insulin resistance (IR) of cardiomyocytes remains unclear. The aim of the present study was to shed light on this issue with a focus on miR-150. We found here that miR-150 level was elevated in myocardium of type 2 diabetes mellitus (T2DM) rat model and in insulin-resistant cardiomyocytes induced by high glucose (25 mM) and high insulin (1 µM). Deregulation of miR-150 downregulated the protein and mRNA levels of glucose transporter 4 (GLUT4) as assessed by western blot, real-time polymerase chain reaction (qPCR), and immunofluorescence assays. Overexpression of miR-150 inhibited glucose utilization in cardiomyocytes as detected by 2-deoxyglucose transport and glucose consumption assays. In contrast, knockdown of miR-150 significantly increased glucose uptake in cardiomyocytes. Moreover, GLUT4 translocation was increased after transfection of miR-150 inhibitor (AMO-150). Collectively, miR-150 reduced glucose utilization by directly decreasing the expression and translocation of GLUT4 in the cardiomyocytes with IR and therefore might be a new therapeutic target for metabolic diseases such as T2DM.


Assuntos
Transportador de Glucose Tipo 4/metabolismo , Resistência à Insulina/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Transporte Biológico/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Glucose/metabolismo , Transportador de Glucose Tipo 4/genética , Coração/fisiopatologia , Insulina/metabolismo , Masculino , MicroRNAs/antagonistas & inibidores , Miocárdio/citologia , Miocárdio/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/ultraestrutura , Cultura Primária de Células , Ratos Sprague-Dawley
13.
Cell Biol Int ; 43(1): 65-72, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30489003

RESUMO

Diabetic cardiomyopathy (DCM) is the leading cause of morbidity and mortality in diabetes mellitus (DM) patients. Previous studies have shown that the transforming growth factor-beta 1 (TGF-ß1)/Smad signaling pathway plays a key role in the development of myocardial fibrosis in DCM. Silymarin (SMN) is used clinically to treat liver disorders and acts by influencing TGF-ß1. However, the possible effects of silymarin on DCM remain to be elucidated. In our study, the DM animal model was induced by streptozotocin (STZ) injection. Fasting blood glucose level was measured, and the structure and function of the heart were measured by hematoxylin and eosin (H&E) and Masson staining, echocardiography, and transmission electron microscopy (TEM). Western blot was used to detect the expression of TGF-ß1, Smad2/3, phosphorylation Smad2/3(p-Smad2/3), and Smad7. Our results showed that silymarin downregulated blood glucose level and significantly improved cardiac fibrosis and collagen deposition in DM rats detected by H&E, Masson staining, and TEM assays. The echocardiography results showed that silymarin administration attenuated cardiac dysfunction in DM rats. Additionally, compared with untreated DM rats, levels of TGF-ß1 and p-Smad2/3 were decreased, whereas Smad7 was increased following silymarin administration. These data demonstrate that silymarin ameliorates DCM through the inhibition of TGF-ß1/Smad signaling, suggesting that silymarin may be a potential target for DCM treatment.


Assuntos
Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/metabolismo , Transdução de Sinais , Silimarina/uso terapêutico , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Animais , Cardiomiopatias Diabéticas/fisiopatologia , Fibrose , Masculino , Miocárdio/patologia , Miocárdio/ultraestrutura , Ratos Sprague-Dawley , Silimarina/farmacologia
14.
Nature ; 502(7472): 532-6, 2013 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-24132232

RESUMO

The miniaturization and integration of frequency-agile microwave circuits--relevant to electronically tunable filters, antennas, resonators and phase shifters--with microelectronics offers tantalizing device possibilities, yet requires thin films whose dielectric constant at gigahertz frequencies can be tuned by applying a quasi-static electric field. Appropriate systems such as BaxSr1-xTiO3 have a paraelectric-ferroelectric transition just below ambient temperature, providing high tunability. Unfortunately, such films suffer significant losses arising from defects. Recognizing that progress is stymied by dielectric loss, we start with a system with exceptionally low loss--Srn+1TinO3n+1 phases--in which (SrO)2 crystallographic shear planes provide an alternative to the formation of point defects for accommodating non-stoichiometry. Here we report the experimental realization of a highly tunable ground state arising from the emergence of a local ferroelectric instability in biaxially strained Srn+1TinO3n+1 phases with n ≥ 3 at frequencies up to 125 GHz. In contrast to traditional methods of modifying ferroelectrics-doping or strain-in this unique system an increase in the separation between the (SrO)2 planes, which can be achieved by changing n, bolsters the local ferroelectric instability. This new control parameter, n, can be exploited to achieve a figure of merit at room temperature that rivals all known tunable microwave dielectrics.

15.
Phytother Res ; 33(10): 2737-2748, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31338905

RESUMO

Coriolus versicolor (CV) is a traditional medicine and food mushroom. Our previous study demonstrated that CV extract exhibited anti-hyperglycemia and anti-insulin resistance effects. However, the effect of CV on cardiac function in diabetic cardiomyopathy (DCM) remains unclear. Therefore, we aimed to investigate the effect of CV on cardiac function in diabetes mellitus (DM) rats. We found that the cardiac dysfunction of DM rats was markedly improved by CV extract treatment. CV extract administration significantly attenuated cardiac fibrosis in DM rats, which was accompanied by suppressed transforming growth factor beta 1 (TGF-ß1)/Smad signaling as indicated by decreased levels of TGF-ß1, p-Smad2, and p-Smad3 and increased Smad7 expression. Moreover, CV extract treatment significantly alleviated cardiac inflammation as shown by decreased levels of NLRP3 receptor, cleaved caspase-1, IL-1ß, and IL-18 in DM rats at least partly due to the inhibition of the NF-κB. In addition, high-glucose treatment induced cardiac fibrosis and increased cardiac inflammation in cardiac fibroblast cells, but these effects were ameliorated by CV extract treatment. Therefore, we conclude that the protective effect of CV on DCM is associated with the suppression of TGF-ß1/Smad signaling and attenuation of NLRP3 inflammasome activation, suggesting that CV extract may be a potential therapeutic agent for DCM.


Assuntos
Agaricales , Cardiomiopatias Diabéticas/tratamento farmacológico , Miocárdio/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Animais , Fibrose , Masculino , NF-kappa B/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/fisiologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
16.
J Cell Mol Med ; 22(10): 4688-4699, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30117680

RESUMO

Our recent study showed that bradykinin increases cell cycling progression and migration of human cardiac c-Kit+ progenitor cells by activating pAkt and pERK1/2 signals. This study investigated whether bradykinin-mediated Ca2+ signalling participates in regulating cellular functions in cultured human cardiac c-Kit+ progenitor cells using laser scanning confocal microscopy and biochemical approaches. It was found that bradykinin increased cytosolic free Ca2+ ( Cai2+ ) by triggering a transient Ca2+ release from ER IP3Rs followed by sustained Ca2+ influx through store-operated Ca2+ entry (SOCE) channel. Blockade of B2 receptor with HOE140 or IP3Rs with araguspongin B or silencing IP3R3 with siRNA abolished both Ca2+ release and Ca2+ influx. It is interesting to note that the bradykinin-induced cell cycle progression and migration were not observed in cells with siRNA-silenced IP3R3 or the SOCE component TRPC1, Orai1 or STIM1. Also the bradykinin-induced increase in pAkt and pERK1/2 as well as cyclin D1 was reduced in these cells. These results demonstrate for the first time that bradykinin-mediated increase in free Cai2+ via ER-IP3R3 Ca2+ release followed by Ca2+ influx through SOCE channel plays a crucial role in regulating cell growth and migration via activating pAkt, pERK1/2 and cyclin D1 in human cardiac c-Kit+ progenitor cells.


Assuntos
Bradicinina/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Proteínas Proto-Oncogênicas c-kit/genética , Células-Tronco/efeitos dos fármacos , Cátions Bivalentes , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ciclina D1/genética , Ciclina D1/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Transporte de Íons/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Miocárdio/citologia , Miocárdio/metabolismo , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Proteína ORAI1/antagonistas & inibidores , Proteína ORAI1/genética , Proteína ORAI1/metabolismo , Cultura Primária de Células , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-kit/metabolismo , Quinolizinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Molécula 1 de Interação Estromal/antagonistas & inibidores , Molécula 1 de Interação Estromal/genética , Molécula 1 de Interação Estromal/metabolismo , Canais de Cátion TRPC/antagonistas & inibidores , Canais de Cátion TRPC/genética , Canais de Cátion TRPC/metabolismo
17.
Cell Physiol Biochem ; 50(4): 1230-1244, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30355944

RESUMO

BACKGROUND/AIMS: Diabetic cardiomyopathy (DCM) is a common complication of diabetes and can cause heart failure, arrhythmia and sudden death. The pathogenesis of DCM includes altered metabolism, mitochondrial dysfunction, oxidative stress, inflammation, cell death and extracellular matrix remodeling. Recently, pyroptosis, a type of programmed cell death related to inflammation, was proven to be activated in DCM. However, the molecular mechanisms underlying pyroptosis in DCM remain elusive. The long non-coding RNA (lncRNA) Kcnq1ot1 participates in many cardiovascular diseases. This study aims to clarify whether Kcnq1ot1 affects cardiac pyroptosis in DCM. METHODS: AC16 cells and primary cardiomyocytes were incubated with 5.5 and 50 mmol/L glucose. Diabetic mice were induced with streptozotocin (STZ). Kcnq1ot1 was silenced both in vitro and in vivo. qRT-PCR was used to detect the expression level of Kcnq1ot1. Immunofluorescence, qRT-PCR and western blot analyses were used to detect the degree of pyroptosis. Echocardiography, hematoxylin and eosin staining, and Masson's trichrome staining were used to detect the cardiac function and morphology in mice. Cell death and function were detected using TUNEL staining, immunofluorescence staining and Ca2+ measurements. RESULTS: The expression of Kcnq1ot1 was increased in patients with diabetes, high glucose-induced cardiomyocytes and diabetic mouse cardiac tissue. Silencing Kcnq1ot1 alleviated pyroptosis by targeting miR-214-3p and caspase-1. Furthermore, silencing Kcnq1ot1 reduced cell death, cytoskeletal structure abnormalities and calcium overload in vitro and improved cardiac function and morphology in vivo. CONCLUSION: Kcnq1ot1 is overexpressed in DCM, and silencing Kcnq1ot1 inhibits pyroptosis by influencing miR-214-3p and caspase-1 expression. We clarified for the first time that Kcnq1ot1 could be a new therapeutic target for DCM.


Assuntos
Cardiomiopatias Diabéticas/patologia , Piroptose , RNA Longo não Codificante/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Antagomirs/metabolismo , Caspase 1/química , Caspase 1/genética , Caspase 1/metabolismo , Células Cultivadas , Citoesqueleto/química , Citoesqueleto/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/patologia , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/genética , Glucose/farmacologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/antagonistas & inibidores , MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose/efeitos dos fármacos , Interferência de RNA , RNA Longo não Codificante/antagonistas & inibidores , RNA Longo não Codificante/genética , RNA Interferente Pequeno/metabolismo
18.
Langmuir ; 34(27): 7971-7980, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29882671

RESUMO

An artificial magnetotactic microbot was created by integrating the microalgal cell with magnetic microbead for its potential application as biomotor in microscale environment. Here, we demonstrate the remote magnetotactic control of the microbot under a low gradient magnetic field (<100 T/m). We characterize the kinematic behavior of the microbots carrying magnetic microbeads of two different sizes, with diameter of 2 and 4.5 µm, in the absence and presence of magnetic field. In the absence of magnetic field, we observed the microbot showed a helical motion as a result of the misalignment between the thrust force and the symmetry axis after the attachment. The microbot bound with a larger magnetic microbead moved with higher translational velocity but rotated slower about its axis of rotation. The viscous force was balanced by the thrust force of the microbot, resulting in a randomized swimming behavior of the microbot at its terminal velocity. Meanwhile, under the influence of a low gradient magnetic field, we demonstrated that the directional control of the microbot was based on following principles: (1) magnetophoretic force was insignificant on influencing its perpendicular motion and (2) its parallel motion was dependent on both self-swimming and magnetophoresis, in which this cooperative effect was a function of separation distance from the magnet. As the microbot approached the magnet, the magnetophoretic force suppressed its self-swimming behavior, leading to a positive magnetotaxis of the microbot toward the source of magnetic field. Our experimental results and kinematic analysis revealed the contribution of mass density variation of particle-and-cell system on influencing its dynamical behavior.

19.
Horm Metab Res ; 50(5): 397-402, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29723898

RESUMO

Non-: alcoholic fatty liver disease (NAFLD) is prevalent worldwide, especially in patients with type 2 diabetes. Liver enzymes are the main warning signs of liver injury and insulin resistance (IR) is critical to NAFLD. This study was aimed to investigate the association between liver enzymes and insulin resistance in type 2 diabetes patients with NAFLD. Data from 212 diabetes patients with NAFLD were analyzed, including 118 males and 94 females who received care from 2014 to 2015. The patients were divided into three groups by severity (mild n=87, moderate n=89, severe n=36). All patients underwent standard clinical and laboratory examinations. Liver enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transferase (GGT) were measured, serum fasting glucose and serum fasting insulin were obtained. IR was assessed using the homeostasis model assessment insulin resistance index (HOMA-IR). Age, sex, and BMI did not significantly differ in patients (p>0.05). Compared with normal levels, elevated ALT and AST were associated with a higher HOMA-IR (p=0.0035, p=0.0096, respectively). HOMA-IR did not significantly differ (p>0.05) between patients with normal and elevated GGT. HOMA-IR increased as the levels of liver enzymes increased, and each enzyme showed a significant association with HOMA-IR (p=0.0166, p<0.0001, and p <0.0001). HOMA-IR differs between normal and elevated ALT and AST. Liver enzymes are associated with HOMA-IR in type 2 diabetes patients with NAFLD. These findings can help evaluate the degree of IR and hepatocellular steatosis in patients and prevent the progression of type 2 diabetes and NAFLD in clinical practice.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Diabetes Mellitus Tipo 2/sangue , Resistência à Insulina , Fígado/enzimologia , Hepatopatia Gordurosa não Alcoólica/sangue , gama-Glutamiltransferase/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Phytother Res ; 32(3): 551-560, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29243310

RESUMO

Patients with type 2 diabetes mellitus (T2DM) are usually with poor immunity and easier to suffer from cancer and microbial infections. Herein, we report an efficient anti-diabetic medicinal mushroom, Coriolus versicolor (CV). This study aimed to investigate the anti-diabetic and anti-insulin-resistance effects of CV aqueous extract in myoblasts (L6 cells) and skeletal muscle of T2DM rat. Our results showed that CV extract treatment significantly reduced blood glucose levels of T2DM rats, whereas CV extract increased glucose consumption in insulin resistant L6 cells. Besides, the translocation and expression of glucose transporter 4 were enhanced by CV extract, which indicated that CV extract was effective in diabetic skeletal muscle. Moreover, CV extract treatments resulted in remarkable anti-insulin-resistance effects, which was reflected by the change of gene and protein expression levels in PI3K/Akt and p38 MAPK pathways. PI3K inhibitor, LY29004, and p38 MAPK inhibitor, SB203580 confirmed it further. In conclusion, our results demonstrated that the CV extract exhibited anti-diabetic and anti-insulin-resistance effects in diabetic skeletal muscle, and the effects were mediated by PI3K/Akt and p38 MAPK pathways. These findings are remarkable when considering the use of commercially available CV by diabetic patients who also suffer from cancer or microbial infections.


Assuntos
Agaricales/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Resistência à Insulina/fisiologia , Músculo Esquelético/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Masculino , Ratos , Ratos Wistar , Transdução de Sinais
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