RESUMO
Phase control over cation exchange (CE) reactions has emerged as an important approach for the synthesis of nanomaterials (NMs), enabling precise determination of their reactivity and properties. Although factors such as crystal structure and morphology have been studied for the phase engineering of CE reactions in NMs, there remains a lack of systematic investigation to reveal the impact for the factors in heterogeneous materials. Herein, we report a molybdenum disulfide induced phase control method for synthesizing multidimensional Co3S4-MoS2 heteronanostructures (HNs) via cation exchange. MoS2 in parent Cu1.94S-MoS2 HNs are proved to affect the thermodynamics and kinetics of CE reactions, and facilitate the formation of Co3S4-MoS2 HNs with controlled phase. This MoS2 induced phase control method can be extended to other parent HNs with multiple dimensions, which shows its diversity. Further, theoretical calculations demonstrate that Co3S4 (111)/MoS2 (001) exhibits a higher adhesion work, providing further evidence that MoS2 enables phase control in the HNs CE reactions, inducing the generation of novel Co3S4-MoS2 HNs. As a proof-of-concept application for crystal phase- and dimensionality-dependent of cobalt sulfide based HNs, the obtained Co3S4-MoS2 heteronanoplates (HNPls) show remarkable performance in hydrogen evolution reactions (HER) under alkaline media. This synthetic methodology provides a unique design strategy to control the crystal structure and fills the gap in the study of heterogeneous materials on CE reaction over phase engineering that are otherwise inaccessible.
RESUMO
BACKGROUND: To investigate the effect of different depth of anesthesia on inflammatory factors and hospital outcomes in elderly patients undergoing laparoscopic radical gastrectomy for gastric cancer, in order to select an appropriate depth of anesthesia to improve the prognosis of patients undergoing surgery and improve the quality of life of patients. METHODS: A total of 80 elderly patients aged 65 and above who underwent laparoscopic radical gastrectomy in our hospital were by convenience sampling and randomly divided into two groups : 55 groups ( group H ) and 45 groups ( group L ), 40 cases in each group. The depth of anesthesia was maintained using a closed-loop target-controlled infusion system: the EEG bispectral index was set to 55 in the H group and 45 in the L group. Venous blood samples were collected 2 h (T2), 24 h (T3) and 72 h (T4) after the start of surgery. The intraoperative dosage of propofol and remifentanil, operation duration, postoperative PACU stay time, intraoperative consciousness occurrence, postoperative hospital stay and postoperative pulmonary inflammatory events were recorded. RESULTS: The patient characteristic of the two groups had no statistical difference and were comparable (P > 0.05). The intraoperative dosage of propofol in group H was lower than that in group L (P < 0.05). Compared with the L group, the plasma IL-6 and IL-10 concentrations in the H group were significantly increased at T2 (P < 0.05), and the plasma IL-10 concentration was significantly increased at T4 (P < 0.05). The plasma concentrations of IL-6 and IL-10 were higher in both groups at T2, T3 and T4 than at T1, while at T4, the concentration of TNF-α in group H was higher than at T1 (P < 0.05). CONCLUSION: When the BIS value of the depth of anesthesia is 45, the perioperative release of inflammatory factors in elderly patients with laparoscopic radical gastrectomy for gastric cancer is less than BIS 55, and does not affect the prognosis.
Assuntos
Laparoscopia , Propofol , Neoplasias Gástricas , Idoso , Humanos , Anestesia Geral , Gastrectomia , Hospitais , Interleucina-10 , Interleucina-6 , Qualidade de Vida , Remifentanil , Neoplasias Gástricas/cirurgia , Fator de Necrose Tumoral alfaRESUMO
Bovine mastitis is the most common disease in dairy cattle. Bacterial infections are the main cause of mastitis. Lipopolysaccharide (LPS), a major structural component of the cell wall of Escherichia coli, is a good inducer used to replicate inflammation models. 8-Methoxypsoralen (8-MOP), a formerly considered photosensitizing agent, has been used in immunotherapy. This study investigated the protective effects of 8-MOP on LPS-induced inflammatory injury in bovine mammary epithelial cells (BMECs). LPS treatment (50 µg/mL for 12 hr) caused a decrease in cell viability, morphological damage, and cell apoptosis. Pretreatment with 8-MOP at concentrations of 25 and 50 µg/ml significantly attenuated LPS-induced inflammation in BMECs. qRT-PCR analysis revealed that the messenger RNA expression of inflammatory cytokines and chemokine (interleukin-1ß [IL-1ß], IL-6, tumor necrosis factor-α, and IL-8) was suppressed by 8-MOP in LPS-stimulated BMECs. Western blot analysis showed that 8-MOP could also reduce the protein levels of cyclooxygenase-2 and promote the translocation of high-mobility group box 1 from the nucleus to cytoplasm. Furthermore, the anti-inflammatory property of 8-MOP was mediated by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells activation and STAT1 phosphorylation. Taken together, 8-MOP could protect cells from inflammatory injury induced by LPS, and may be a potential agent against bovine mastitis.
Assuntos
Células Epiteliais/efeitos dos fármacos , Inflamação , Mastite Bovina/tratamento farmacológico , Metoxaleno/farmacologia , Animais , Bovinos , Células Epiteliais/patologia , Feminino , Inflamação/tratamento farmacológico , Inflamação/veterinária , Janus Quinases/metabolismo , Lipopolissacarídeos/química , Glândulas Mamárias Animais/patologia , Mastite Bovina/induzido quimicamente , NF-kappa B/metabolismo , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Intracellular pH (pHi) is an important parameter associated with cellular behaviors and pathological conditions. Sensing pHi and monitoring its changes are essential but challenging due to the lack of high-sensitive probes. Herein, a ratiometric fluorescent probe with ultra pH-sensitivity is developed based on hairpin-contained i-motif strand (I-strand, labeled with Rhodamine Green and BHQ2 at two termini) and complementary strand (C-strand, labeled with Rhodamine Red at its 5'-end). At neutral pH, both I-strand and C-strand hybridize into a rigid duplex (I-C), which holds the Rhodamine Red and the BHQ2 in close proximity. As a result, the fluorescence emission (F597 nm) of the Rhodamine Red is strongly suppressed, while the Rhodamine Green (F542 nm) is in a "signal on" state. However, the slightly acidic pH enforced the I-strand to form an intramolecular i-motif and initiated the dehybridization of I-C duplex, leading to Rhodamine Red in a "signal on" state and a decreased fluorescence of Rhodamine Green. The ratio (F542 nm/F597 nm) can be used as a signal for pH sensing. Due to the rational internal hairpin design of I-C duplex probe, almost 70-fold change in the ratio was observed in the physiological pH range (6.50-7.40). This probe possesses efficient stability, fast response, and reversible pH measurement capabilities. Furthermore, intracellular application of the ratiometric probe was demonstrated on the example of SMMC-7721 cells. With different recognition elements in engineering of i-motif based platforms, the design might hold great potential to become a versatile strategy for intracellular pH sensing.
Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Corantes Fluorescentes/química , Rodaminas/química , Linhagem Celular Tumoral , Citoplasma/química , Humanos , Concentração de Íons de Hidrogênio , Conformação de Ácido Nucleico , Imagem Óptica/métodos , Espectrometria de Fluorescência/métodosRESUMO
Sjögren's syndrome (SjS) and systemic lupus erythematosus (SLE) are common systemic autoimmune diseases, which impact not only patient health but also their quality of life. miRNA-146a is a microRNA that participates in the pathophysiology of SjS and SLE. In this investigation, we conducted a meta-analysis to determine the relationship of miR-146a to primary SjS (PSS) and to SLE. The following databases were interrogated; Pubmed, Cochrane Central Register of Controlled Trials, WANFANG, Chinese National Knowledge Infrastructure, and WEIPU. Standard mean difference with 95% confidence intervals (CI) were used to study the relationship between miRNA-146a expression and thee diseases by random-effects model. A total of six studies, with 158 cases and 124 controls were included for the meta-analysis. The meta-analysis shows that miRNA-146a expression is associated with the risk of PSS (MD = 6.32, p = 0.005). No relationship between miR-146a expression and SLE was identified (MD = -0.86, p = 0.26). SLE subgroup analysis (peripheral blood mononuclear cells and serum) confirmed this result. The risk for PSS is related to miR-146a expression, while miRNA-146a expression is not related to SLE. As such, miRNA-146a may serve as a novel biomarker for the diagnosis of PSS, but not SLE.
Assuntos
Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , MicroRNAs/metabolismo , Síndrome de Sjogren/genética , Estudos de Casos e Controles , Feminino , Marcadores Genéticos , Humanos , Leucócitos Mononucleares/metabolismo , Masculino , Polimorfismo de Nucleotídeo Único , Qualidade de Vida , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de RiscoRESUMO
DNA-based activatable theranostic nanoprobes are still unmet for in vivo applications. Here, by utilizing the "induced-fit effect", a smart split aptamer-based activatable theranostic probe (SATP) was first designed as "nanodoctor" for cancer-activated in vivo imaging and in situ drug release. The SATP assembled with quenched fluorescence and stable drug loading in its free state. Once binding to target proteins on cell surface, the SATP disassembled due to recognition-triggered reassembly of split aptamers with activated signals and freed drugs. As proof of concept, split Sgc8c against CEM cancer was used for theranostic studies. Benefiting from the design without blocking aptamer sequence, the SATP maintained an excellent recognition ability similar to intact Sgc8c. An "incubate-and-detect" assay showed that the SATP could significantly lower background and improve signal-to-background ratio (â¼4.8 times of "always on" probes), thus affording high sensitivity for CEM cell analysis with 46 cells detected. Also, its high selectivity to target cells was demonstrated in analyzing mixed cell samples and serum samples. Then, using doxorubicin as a model, highly specific drug delivery and cell killing was realized with minimized toxicity to nontarget cells. Moreover, in vivo and ex vivo investigations also revealed that the SATP was specifically activated by CEM tumors inside mice. Especially, contrast-enhanced imaging was achieved in as short as 5 min, thus, laying a foundation for rapid diagnosis and timely therapy. As a biocompatible and target-activatable strategy, the SATP may be widely applied in cancer theranostics.
Assuntos
Aptâmeros de Nucleotídeos/química , DNA/análise , Neoplasias/diagnóstico por imagem , Nanomedicina Teranóstica , Animais , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/farmacologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Imagem ÓpticaRESUMO
Colorimetric analysis is promising in developing facile, fast, and point-of-care cancer diagnosis techniques, but the existing colorimetric cancer cell assays remain problematic because of dissatisfactory sensitivity as well as complex probe design or synthesis. To solve the problem, we here present a novel colorimetric analytical strategy based on iodide-responsive Cu-Au nanoparticles (Cu-Au NPs) combined with the iodide-catalyzed H2O2-TMB (3,3,5,5-tetramethylbenzidine) reaction system. In this strategy, bimetallic Cu-Au NPs prepared with an irregular shape and a diameter of â¼15 nm could chemically absorb iodide, thus indirectly inducing colorimetric signal variation of the H2O2-TMB system. By further utilizing its property of easy biomolecule modification, a versatile colorimetric platform was constructed for detection of any target that could cause the change of Cu-Au NPs concentration via molecular recognition. As proof of concept, an analysis of human leukemia CCRF-CEM cells was performed using aptamer Sgc8c-modified Cu-Au NPs as the colorimetric probe. Results showed that Sgc8c-modified Cu-Au NPs successfully achieved a simple, label-free, cost-effective, visualized, selective, and ultrasensitive detection of cancer cells with a linear range from 50 to 500 cells/mL and a detection limit of 5 cells in 100 µL of binding buffer. Moreover, feasibility was demonstrated for cancer cell analysis in diluted serum samples. The iodide-responsive Cu-Au NP-based colorimetric strategy might not only afford a new design pattern for developing cancer cell assays but also greatly extend the application of the iodide-catalyzed colorimetric system.
Assuntos
Colorimetria , Cobre/química , Ouro/química , Iodetos/química , Nanopartículas Metálicas/química , Aptâmeros de Nucleotídeos/química , Benzidinas/química , Catálise , Linhagem Celular Tumoral , Humanos , Peróxido de Hidrogênio/química , Neoplasias/diagnóstico , Oxirredução , Sistemas Automatizados de Assistência Junto ao LeitoRESUMO
A novel channel-switch-mode strategy for simultaneous sensing of Fe(3+) and Hg(2+) is developed with dual-excitation single-emission graphene quantum dots (GQDs). By utilizing the dual-channel fluorescence response performance of GQDs, this strategy achieved a facile, low-cost, masking agent-free, quantitative and selective dual-ion assay even in mixed ion samples and practical water samples.
Assuntos
Técnicas de Química Analítica/instrumentação , Grafite/química , Ferro/análise , Mercúrio/análise , Pontos Quânticos/química , Ferro/química , Mercúrio/química , Espectrometria de Fluorescência , Fatores de TempoRESUMO
DNA-templated copper nanoparticles (CuNPs) have emerged as promising fluorescent probes for biochemical assays, but the reported monomeric CuNPs remain problematic because of weak fluorescence and poor stability. To solve this problem, a novel concatemeric dsDNA-templated CuNPs (dsDNA-CuNPs) strategy was proposed by introducing the rolling circle replication (RCR) technique into CuNPs synthesis. In this strategy, a short oligonucleotide primer could trigger RCR and be further converted to a long concatemeric dsDNA scaffold through hybridization. After the addition of copper ions and ascorbate, concatemeric dsDNA-CuNPs could effectively form and emit intense fluorescence in the range of 500-650 nm under a 340 nm excitation. In comparison with monomeric dsDNA-CuNPs, the sensitivity of concatemeric dsDNA-CuNPs was greatly improved with ~10,000 folds amplification. And their fluorescence signal was detected to reserve ~60% at 2.5 h after formation, revealing ~2 times enhanced stability. On the basis of these advantages, microRNA let-7d was selected as the model target to testify this strategy as a versatile assay platform. By directly using let-7d as the primer in RCR, the simple, low-cost, and selective microRNA detection was successfully achieved with a good linearity between 10 and 400 pM and a detection limit of 10 pM. The concatemeric dsDNA-CuNPs strategy might be widely adapted to various analytes that can directly or indirectly induce RCR.
Assuntos
Cobre/química , DNA/química , Nanopartículas Metálicas/química , MicroRNAs/análise , Primers do DNA , Replicação do DNA , DNA Circular/química , DNA Concatenado/química , Corantes Fluorescentes , Sensibilidade e EspecificidadeRESUMO
Activatable aptamer probes (AAPs) have emerged as a promising strategy in cancer diagnostics, but existing AAPs remain problematic due to complex design and synthesis, instability in biofluids, or lack of versatility for both in vitro and in vivo applications. Herein, we proposed a novel AAP strategy for cancer cell probing based on fluorophore-labeled aptamer/single-walled carbon nanotube (F-apt/SWNT) ensembles. Through π-stacking interactions and proximity-induced energy transfer, F-apt/SWNT with quenched fluorescence spontaneously formed in its free state and realized signal activation upon targeting surface receptors of living cells. As a demonstration, Sgc8c aptamer was used for in vitro analysis and in vivo imaging of CCRF-CEM cancer cells. It was found that self-assembled Cy5-Sgc8c/SWNT held robust stability for biological applications, including good dispersity in different media and ultralow fluorescence background persistent for 2 h in serum. Flow cytometry assays revealed that Cy5-Sgc8c/SWNT was specifically activated by target cells with dramatic fluorescence elevation and showed improved sensitivity with as low as 12 CCRF-CEM cells detected in mixed samples containing ~100,000 nontarget cells. In vivo studies confirmed that specifically activated fluorescence was imaged in CCRF-CEM tumors, and compared to "always on" probes, Cy5-Sgc8c/SWNT greatly reduced background signals, thus resulting in contrast-enhanced imaging. The general applicability of the strategy was also testified by detecting Ramos cells with aptamer TD05. It was implied that F-apt/SWNT ensembles hold great potential as a simple, stable, sensitive, specific, and versatile activatable platform for both in vitro cancer cell detection and in vivo cancer imaging.
Assuntos
Aptâmeros de Nucleotídeos/química , Corantes Fluorescentes/química , Microscopia Confocal , Nanotubos de Carbono/química , Neoplasias/patologia , Animais , Carbocianinas/química , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias/metabolismo , Oxirredução , Espectrometria de Fluorescência , Imagem com Lapso de Tempo , Transplante HeterólogoRESUMO
Mitochondrial encephalomyopathies (ME) are frequently associated with mutations of mitochondrial DNA, but the pathogenesis of a subset of ME (sME) remains elusive. Here we report that haploinsufficiency of a mitochondrial inner membrane protein, Mic60, causes progressive neurological abnormalities with insulted mitochondrial structure and neuronal loss in mice. In addition, haploinsufficiency of Mic60 reduces mitochondrial membrane potential and cellular ATP production, increases reactive oxygen species, and alters mitochondrial oxidative phosphorylation complexes in neurons in an age-dependent manner. Moreover, haploinsufficiency of Mic60 compromises brain glucose intake and oxygen consumption in mice, resembling human ME syndrome. We further discover that MIC60 protein expression declined significantly in human sME, implying that insufficient MIC60 may contribute for pathogenesis of human ME. Notably, systemic administration of antioxidant N-acetylcysteine largely reverses mitochondrial dysfunctions and metabolic disorders in haplo-insufficient Mic60 mice, also restores neurological abnormal symptom. These results reveal Mic60 is required in the maintenance of mitochondrial integrity and function, and likely a potential therapeutics target for mitochondrial encephalomyopathies.
Assuntos
Encefalomiopatias Mitocondriais , Animais , Camundongos , Humanos , Encefalomiopatias Mitocondriais/genética , Encefalomiopatias Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , Mitocôndrias/metabolismo , DNA Mitocondrial , AntioxidantesRESUMO
The DNA polymerase assay is fundamental for related molecular biology investigations and drug screenings, however, the commonly used radioactive method is laborious and restricted. Herein, we report a novel, simple and cost-effective fluorometric DNA polymerase detection method by utilizing graphene oxide (GO) as a signal switch. In this strategy, in the absence of DNA polymerase, the fluorophore-labeled template ssDNA could be strongly adsorbed and almost entirely quenched by GO. However, as DNA polymerase exists, the polymerized dsDNA product might lead to a much lower quenching efficiency after addition of GO due to the much weaker interaction of dsDNA with GO than ssDNA, thus resulting in a much higher fluorescence signal detected. As proof of concept, the quantitative DNA polymerase activity assay was performed using the Klenow fragment exo(-) (KF(-)) as a model. It was confirmed that, after optimization of detection conditions, KF(-) activity could be sensitively detected through facile fluorescence measurements, with a detection limit of 0.05 U mL(-1) and a good linear correlation between 0.05-2.5 U mL(-1) (R(2) = 0.9928). In addition, this GO-based method was further inspected to evaluate the inhibitive behaviors of several drugs toward KF(-) activity, the result of which firmly demonstrated its potential application in polymerization-targeted drug screening.
Assuntos
DNA Polimerase Dirigida por DNA/análise , Fluorometria , Grafite/química , Óxidos/química , DNA de Cadeia Simples/química , Corantes Fluorescentes/químicaRESUMO
Two new species of eriophyoid mites are described and illustrated from Guangxi, China: Acaphylla quercus sp. nov. collected on Quercus glauca Thunb. (Fagaceae), Rhyncaphytoptus miliusius sp. nov. collected on Miliusa sinensis Finet Gagnep. (Annonaceae). We further report Cecidodectes euzonus Nalepa, 1917, collected on Trema tomentosa (Roxb.) H.Hara (Cannabaceae), for the first time from China. All the species are vagrants on lower leaf surface causing no apparent damage to their host plants.
Assuntos
Ácaros , Animais , China , PlantasRESUMO
Insulin inhibits ischemia/reperfusion-induced myocardial apoptosis through the activation of a survival signaling cascade including the phosphatidylinositol 3-kinase (PI3K)-Akt pathway. However, the down-stream mechanism of PI3K remains elusive. This study is aimed at investigating whether survivin (SVV) plays a role in the insulin-induced anti-apoptotic effect in the ischemic/reperfused (I/R) hearts, and if so, further determining the signaling mechanism involved. Isolated adult rat hearts were subjected to 30 min regional ischemia followed by reperfusion with or without insulin (10(-7)mol/L) at the onset of reperfusion. Reperfusion with insulin inhibited myocardial apoptosis and reduced infarct size, along with significantly up-regulated myocardial SVV expression (5.9±0.3 Group MI/R+Ins vs. 2.1±0.1 Group MI/R, p<0.05) and increased phosphorylations of mTOR and p70S6K compared with I/R group, which was blocked by pretreatment of PI3K inhibitor LY294002. Rapamycin, a specific mTOR inhibitor, did not alter insulin-induced Akt phosphorylation but significantly inhibited SVV expression (from 6.1±0.3 to 3.0±0.15, p<0.05). Moreover, rapamycin blunted insulin-induced anti-apoptosis in the I/R hearts (8.1±0.4% vs. 16.5±1.8%, p<0.05). To further ascertain the role of SVV in insulin-induced cardioprotection, cardiomyocytes were transfected with adenovirus encoding SVV (gain-of-function) or siRNA targeting SVV (loss-of-function). Overexpression of SVV decreased I/R-induced cardiomyocyte apoptosis in vitro, while siRNA targeting SVV significantly blunted the anti-apoptotic effect of insulin. Taken together, these results suggest a novel role of PI3K/Akt/mTOR/SVV signaling in the cardioprotective effect of insulin.
Assuntos
Insulina/farmacologia , Proteínas Associadas aos Microtúbulos/metabolismo , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Marcação In Situ das Extremidades Cortadas , Masculino , Proteínas Associadas aos Microtúbulos/genética , Fosfatidilinositol 3-Quinase/metabolismo , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Survivina , Serina-Treonina Quinases TOR/metabolismoRESUMO
Two new Diptacus species and one new Trimeroptes species (Acari: Eriophyoidea: Diptilomiopidae) are described and illustrated from China: Diptacus suichangensis sp. nov. on Aralia chinensis L. (Araliaceae) and Diptacus pyracanthae sp. nov. on Pyracanthafortuneana (Maxim.) Li (Rosaceae), and Trimeroptes longlinensis sp. nov. on Carpinus sp. (Betulaceae). These new species were found to be vagrant on the lower surface of their associated plants leaves, albeit with no apparent damage observed.
Assuntos
Ácaros e Carrapatos , Ácaros , Rosaceae , Animais , China , Folhas de Planta , PlantasRESUMO
Cyclic stretch (CS) mediates different cellular functions in vascular smooth muscle cells and involves in neointimal hyperplasia and subsequent atherosclerosis of vein grafts. Here, we investigated whether CS can modulate stromal cell-derived factor-1alpha (SDF-1alpha)/CXCR4 axis in human saphenous vein smooth muscle cells. We found CS induced the upregulation of SDF-1alpha and CXCR4 in human saphenous vein smooth muscle cells in vitro, which was dependent on PI3K/Akt/mTOR pathway. Furthermore, CS augmented human saphenous vein smooth muscle migration and focal adhesion kinase (FAK) activation by PI3K/Akt/mTOR pathway. Interestingly, the upregulation of SDF-1alpha/CXCR4 axis was instrumental in CS-induced saphenous vein smooth muscle cell migration and FAK activation, as showed by AMD3100, an inhibitor of SDF-1alpha/CXCR4 axis, partially but significantly blocked the CS-induced cellular effects. Thus, those data suggested SDF-1alpha/CXCR4 axis involves in CS-mediated cellular functions in human saphenous vein smooth muscle cells.
Assuntos
Quimiocina CXCL12/biossíntese , Mecanotransdução Celular , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Receptores CXCR4/biossíntese , Veia Safena/metabolismo , Movimento Celular , Quimiocina CXCL12/genética , Humanos , Músculo Liso Vascular/fisiologia , Miócitos de Músculo Liso/fisiologia , Receptores CXCR4/genética , Veia Safena/citologia , Veia Safena/fisiologia , Resistência à Tração , Regulação para CimaRESUMO
Diabetes mellitus (DM) can increase the risk of Alzheimer's disease (AD) in patients. However, no effective approaches are available to prevent its progression and development. Recently, autophagy dysfunction was identified to be involved in the pathogenesis of neurodegenerative diseases. This study was designed to investigate the effect of metformin on hyperphosphorylated tau proteins in diabetic encephalopathy (DE) by regulating autophagy clearance. db/db mice were randomly divided into four groups, db/+ mice were used as control group. Twelve-week old male db/db mice received consecutive intraperitoneal injection of 200â¯mg/kg/d metformin or (and) 10â¯mg/kg/d chloroquine for eight weeks. Morris water maze (MWM) tests were performed to test cognitive functions before the mice were euthanized. Metformin attenuated cognitive impairment in db/db mice, reduced hyperphosphorylated tau proteins, restored the impaired autophagy in diabetic mice, all of which were reversed by inhibiting of autophagy activity. In high glucose-cultured HT22 cells, metformin increased autophagy in a dose-dependent manner. Besides, metformin enhanced autophagy activity in an AMPK dependent manner. These data show that metformin may reduce tauopathy and improve cognitive impairment in db/db mice by modulating autophagy through the AMPK dependent pathway. These findings highlight metformin as a new therapeutic strategy for the treatment of DE.