Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 115
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Biochem Genet ; 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581475

RESUMO

Spinal muscular atrophy (SMA) is a neuromuscular disorder with an autosomal recessive inheritance pattern. Patients with severe symptoms may suffer respiratory failure, leading to death. The homozygous deletion of exon 7 in the SMN1 gene accounts for nearly 95% of all cases. Population carrier screening for SMA and prenatal diagnosis by amniocentesis for high-risk couples can assist in identifying the risk of fetal disease. We provided the SMA carrier screening process to 55,447 pregnant women in Yancheng from October 2020 to December 2022. Among them, 8185 participated in this process, with a participation rate of around 14.76% (95% CI 14.47-15.06%). Quantitative real-time polymerase chain reaction (qPCR) was used to detect deletions of SMN1 exons 7 and 8 (E7, E8) in screened pregnant women. 127 were identified as carriers (111 cases of E7 and E8 heterozygous deletions, 15 cases of E7 heterozygous deletions, and 1 case of E7 heterozygous deletions and E8 homozygous deletions), resulting in a carrying rate of around 1.55% (95% CI 1.30-1.84%). After genetic counseling, 114 spouses of pregnant women who tested positive underwent SMA carrier screening; three of them were screened as SMA carriers. Multiplexed ligation-dependent probe amplification (MLPA) was used for the prenatal diagnosis of the fetuses of high-risk couples. Two of them exhibited two copies of SMN1 exon 7 (normal), and the pregnancy was continued; one exhibited no copies of SMN1 exon 7 and exon 8 (SMA patient), and the pregnancy was terminated. Analyzing SMN1 mutations in Yancheng and provide clinical evidence for SMA genetic counseling and birth defect prevention. Interventional prenatal diagnosis for high-risk families can promote informed reproductive selection and prepare for the fetus's early treatment.

2.
Chem Biodivers ; 21(2): e202301703, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38055204

RESUMO

Three undescribed limonoids (1-3), named aglaians G-I, and one new natural product azedaralide (4), together with nine known analogues (5-13) were isolated from the branches and leaves of Aglaia lawii by RP C18 column, silica gel column, Sephadex LH-20 column chromatography and preparative HPLC. The structures of the new compounds were elucidated by IR, HRESIMS, 1D, 2D NMR, electronic circular dichroism (ECD) calculations and X-ray crystallography diffraction analysis. The results of bioassay showed that the compound 12 exhibited potential inhibitory activity against six human tumor cell lines (MDA-MB-231, MCF-7, Ln-cap, A549, HeLa and HepG-2) with IC50 values as 8.0-18.6 µM.


Assuntos
Aglaia , Antineoplásicos , Limoninas , Humanos , Aglaia/química , Limoninas/farmacologia , Limoninas/química , Estrutura Molecular , Linhagem Celular Tumoral
3.
Odontology ; 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38900231

RESUMO

Collagen type I alpha1 (COL1A1) has been found to be abnormal expressed in oral squamous cell carcinoma (OSCC) tissues, but its role and mechanism in OSCC need to be further elucidated. The expression levels of COL1A1 and methyltransferase-like 3 (METTL3) were measured by quantitative real-time PCR and western blot. Cell growth and metastasis were determined by CCK8, colony formation, EdU, flow cytometry and transwell assays. MeRIP, Co-IP and dual-luciferase reporter assays were performed to explore the interplay of COL1A1 and METTL3. COL1A1 mRNA stability was confirmed by Actinomycin D assay. Mice xenograft models were constructed to perform in vivo experiments. COL1A1 and METTL3 were upregulated in OSCC. COL1A1 knockdown suppressed OSCC cell growth and metastasis, while its overexpression had an opposite effect. The stability of COL1A1 mRNA was regulated by the m6A methylation of METTL3. METTL3 overexpression promoted OSCC cell growth and metastasis, and its knockdown-mediated OSCC cell function inhibition could be abolished by COL1A1 overexpression. Besides, silencing of METTL3 reduced OSCC tumor growth by reducing COL1A1 expression. METTL3-stabilized COL1A1 promoted OSCC progression, providing an exact molecular target for the treatment of OSCC.

4.
Angew Chem Int Ed Engl ; 63(21): e202401441, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38533760

RESUMO

Zn metal as a promising anode of aqueous batteries faces severe challenges from dendrite growth and side reactions. Here, tetraphenylporphyrin tetrasulfonic acid (TPPS) is explored as an electrolyte additive for advanced Zn anodes. It is interesting to note that TPPS spontaneously assembles into unique aggregates. As they adsorb on the Zn anode, the aggregates enhance the resistance to electrolyte percolation and dendrite growth compared to single molecules. Meanwhile, TPPS facilitates anion association in the solvation sheath of Zn2+, and boosts the transference number of Zn2+ up to 0.95. Therefore, anion-related side reactions and anion-induced electrode overpotentials are reduced accordingly. In this context, the electrolyte containing TPPS exhibits excellent electrochemical performance. Even under a high loading of MnO2 (25 mg cm-2), a limited Zn supply (N/P ratio=1.7), and a lean electrolyte (15 µL mAh-1), the full cells still represent a higher cumulative capacity compared to the reported data. The advantages of this electrolyte are also adapted to other cathode materials. The pouch cells of Zn||NaV3O8 ⋅ 1.5H2O realize a capacity of ~0.35 Ah at 0.4 C under harsh conditions.

5.
Opt Express ; 31(2): 2768-2779, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785283

RESUMO

Stratospheric aerosols play an important role in the atmospheric chemical and radiative balance. To detect the stratospheric aerosol layer, a 1064 nm lidar with high resolution and large dynamic range is developed using a superconducting nanowire single-photon detector (SNSPD). Measurements are typically performed at 1064 nm for its sensitivity to aerosol, whereas detectors are limited by low efficiency and high dark count rate (DCR). SNSPDs are characterized by high efficiency in the infrared wavelength domain, as well as low noise and dead time, which can significantly enhance the signal quality. However, it is still challenging to build an SNSPD with both large active area and high count rate. To improve the maximal count rate (MCR) so as to avoid saturation in the near range, a 16-pixel interleaved SNSPD array and a multichannel data acquisition system are developed. As a reference, a synchronous system working at 532 nm is applied. In a continuous comparison experiment, backscatter ratio profiles are retrieved with resolutions of 90 m/3 min, and the 1064 nm system shows better performance, which is sensitive to aerosols and immune to the contamination of the ozone absorption and density of molecule change in the lower stratosphere.

6.
Crit Rev Food Sci Nutr ; : 1-24, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37599638

RESUMO

Momordica charantia L. is a well-known medicine and food homology plant with high pharmaceutical and nutritional values. Polysaccharides are carbohydrate polymers connected by glycosidic bonds, one of the key functional ingredients of M. charantia. Recently, M. charantia polysaccharides (MCPs) have attracted much attention from industries and researchers due to their anti-oxidant, anti-tumor, anti-diabetes, anti-bacteria, immunomodulatory, neuroprotection, and organ protection activities. However, the development and utilization of MCPs-based functional foods and medicines were hindered by the lack of a deeper understanding of the structure-activity relationship (SAR), structural modification, applications, and safety of MCPs. Herein, we provide an overview of the extraction, purification, structural characterization, bioactivities, and mechanisms of MCPs. Besides, SAR, toxicities, application, and influences of the modification associated with bioactivities are spotlighted, and the potential development and future study direction are scrutinized. This review provides knowledge and research underpinnings for the further research and application of MCPs as therapeutic agents and functional food additives.

7.
J Biochem Mol Toxicol ; 37(9): e23412, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37341456

RESUMO

Cadmium (Cd) is widely distributed in the environment and easy adsorbed by living organisms with adverse effects. Exposure to Cd-contaminated food may disrupt lipid metabolism and increase human health risk. To study the perturbation effect of Cd on lipid metabolism in vivo, 24 male Sprague-Dawley (SD) rats were randomly assigned four groups and treated by Cd chloride solution (0, 1.375 mg/kg, 5.5 mg/kg, 22 mg/kg) for 14 days. The characteristic indexes of serum lipid metabolism were analyzed. Afterwards, untargeted metabolomics analysis was applied to explore the adverse effects of Cd on rats by liquid chromatography coupled with mass spectrometry (LC-MS). The results revealed that Cd exposure obviously decreased the average serum of triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) and caused an imbalance of endogenous compounds in the 22 mg/kg Cd-exposed group. Compared with the control group, 30 metabolites with significant differences were identified in the serum. Our results indicated that Cd caused lipid metabolic disorders in rats by disrupting linoleic acid and glycerophospholipid metabolism pathways. Furthermore, there were three kinds of remarkable differential metabolites-9Z,12Z-octadecadienoic acid, PC(20:4(8Z,11Z,14Z,17Z)/0:0), and PC(15:0/18:2(9Z,12Z)), which enriched the two significant metabolism pathways and could be the potential biomarkers.


Assuntos
Cádmio , Ácido Linoleico , Humanos , Ratos , Masculino , Animais , Ratos Sprague-Dawley , Cádmio/toxicidade , Metabolismo dos Lipídeos , Metabolômica , Biomarcadores , Glicerofosfolipídeos
8.
Environ Toxicol ; 38(11): 2621-2631, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37466199

RESUMO

Lung cancer is the leading cause of cancer-related death worldwide and non-small cell lung cancer (NSCLC) represents 85%. Mougeotia nummuloides and Spirulina major have been reported to possess anticancer properties. 1-Monopalmitin (1-Mono) is the principle active constituent in these natural plants. It is debating whether 1-Mono exerts antitumor effects. Therefore, we explored the role of 1-Mono in lung cancer in vitro. Results showed that 1-Mono significantly inhibited A549 and SPC-A1 cell proliferation, induced G2/M arrest and caspase-dependent apoptosis. Moreover, it suppressed the protein expression of inhibitors of apoptosis proteins (IAPs). It was further demonstrated that 1-Mono activated the PI3K/Akt pathway, suppression of PI3K/Akt activities with LY294002 and Wortmannin partially attenuated 1-Mono-mediated anticancer activities, indicating that 1-Mono-induced antitumor effects is dependent on PI3K/Akt pathway. 1-Mono induced cytoprotective autophagy since autophagy inhibitor Chloroquine dramatically enhanced 1-Mono-induced cytotoxicity. In summary, our results showed 1-Mono kills lung cancer through PI3K/Akt pathway, providing novel options for lung cancer administration.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Apoptose , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Pontos de Checagem da Fase G2 do Ciclo Celular , Proliferação de Células
9.
Molecules ; 29(1)2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38202622

RESUMO

Five undescribed steroids and one sesquiterpene, named Aglaians A-F, along with sixteen known analogs, have been isolated from the branches and leaves of Aglaia lawii. Its structure was elucidated by IR, HRESIMS, 1D and 2D NMR, quantum-chemical calculations, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction analysis. The cytotoxic and antibacterial activities of six human tumor cell lines were evaluated (MDA-MB-231, MCF-7, Ln-cap, A549, HeLa, and HepG-2), and four strains of bacteria (Bacterium subtilis, Phytophthora cinnamomic, Acrogenic bacterium, and Ralstonia solanacearum). The bioassay results indicated that compounds 3 and 5 exhibited moderate antitumor activity with IC50 values ranging from 16.72 to 36.14 µM. Furthermore, compounds 3-5 possess antibacterial activities against four bacteria with MIC values of 25-100 µM.


Assuntos
Aglaia , Sesquiterpenos , Humanos , Esteroides/farmacologia , Antibacterianos/farmacologia , Linhagem Celular Tumoral , Sesquiterpenos/farmacologia
10.
J Transl Med ; 20(1): 445, 2022 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-36184622

RESUMO

BACKGROUND: According to the Global Cancer Statistics in 2020, the incidence and mortality of colorectal cancer (CRC) rank third and second among all tumors. The disturbance of ubiquitination plays an important role in the initiation and development of CRC, but the ubiquitinome of CRC cells and the survival-relevant ubiquitination are poorly understood. METHODS: The ubiquitinome of CRC patients (n = 6) was characterized using our own data sets of proteomic and ubiquitin-proteomic examinations. Then, the probable survival-relevant ubiquitination was searched based on the analyses of data sets from public databases. RESULTS: For the ubiquitinomic examination, we identified 1690 quantifiable sites and 870 quantifiable proteins. We found that the highly-ubiquitinated proteins (n ≥ 10) were specifically involved in the biological processes such as G-protein coupling, glycoprotein coupling, and antigen presentation. Also, we depicted five motif sequences frequently recognized by ubiquitin. Subsequently, we revealed that the ubiquitination content of 1172 proteins were up-regulated and 1700 proteins were down-regulated in CRC cells versus normal adjacent cells. We demonstrated that the differentially ubiquitinated proteins were relevant to the pathways including metabolism, immune regulation, and telomere maintenance. Then, integrated with the proteomic datasets from the Clinical Proteomic Tumor Analysis Consortium (CPTAC) (n = 98), we revealed that the increased ubiquitination of FOCAD at Lys583 and Lys587 was potentially associated with patient survival. Finally, we depicted the mutation map of FOCAD and elucidated its potential functions on RNA localization and translation in CRC. CONCLUSIONS: The findings of this study described the ubiquitinome of CRC cells and identified abnormal ubiquitination(s) potentially affecting the patient survival, thereby offering new probable opportunities for clinical treatment.


Assuntos
Neoplasias Colorretais , Proteínas Ubiquitinadas , Neoplasias Colorretais/patologia , Humanos , Proteômica , RNA/metabolismo , Ubiquitina/genética , Ubiquitina/metabolismo , Proteínas Ubiquitinadas/genética , Proteínas Ubiquitinadas/metabolismo , Ubiquitinação
11.
J Transl Med ; 20(1): 510, 2022 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335368

RESUMO

BACKGROUND: Diabetic kidney disease (DKD) is among the most important causes for chronic kidney disease. Anthocyanins (ANT) are polyphenolic compounds present in various food and play an important role in ameliorating hyperglycemia and insulin sensitivity. However, the effects of ANT in DKD are still poorly understood. This study aimed to investigate the effect of ANT (cyanidin-3-O-glucoside [C3G]) on the renal function of DKD, and whether the anti-DKD effect of ANT is related to metabolic pathways. METHODS: To explore the role of ANT in DKD, we performed the examination of blood glucose, renal function, and histopathology. As for the mechanism, we designed the label-free quantification proteomics and nontargeted metabolomics analysis for kidney and serum. Subsequently, we revealed the anti-DKD effect of ANT through the bioinformatic analysis. RESULTS: We showed that the fasting blood glucose level (- 6.1 mmol/L, P = 0.037), perimeter of glomerular lesions (- 24.1 µm, P = 0.030), fibrosis score of glomerular (- 8.8%, P = 0.002), and kidney function (Cystatin C: - 701.4 pg/mL, P = 0.043; urine creatinine: - 701.4 mmol/L, P = 0.032) were significantly alleviated in DKD mice after ANT treatment compared to untreated in the 20th week. Further, proteins and metabolites in the kidneys of DKD mice were observed to be dramatically altered due to changes in amino acid metabolism with ANT treatment; mainly, taurine and hypotaurine metabolism pathway was upregulated (P = 0.0001, t value = 5.97). Furthermore, upregulated tryptophan metabolism (P < 0.0001, t value = 5.94) and tyrosine metabolism (P = 0.0037, t value = 2.91) pathways had effects on serum of DKD mice as responsed ANT regulating. CONCLUSIONS: Our results suggested that prevention of the progression of DKD by ANT could be related to the regulation of amino acid metabolism. The use of dietary ANT may be one of the dietary strategies to prevent and treat DKD.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Camundongos , Animais , Nefropatias Diabéticas/metabolismo , Antocianinas/farmacologia , Antocianinas/uso terapêutico , Glicemia , Rim/patologia , Aminoácidos , Diabetes Mellitus/patologia
12.
Opt Express ; 30(16): 29485-29494, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36299122

RESUMO

Coding technology provides new ideas for spatial resolution enhancement of coherent Doppler wind lidar (CDWL). To improve the performance of coding CDWL for ultra-fine-wind field detection, the crosstalk between neighboring laser pulses is analyzed in theory. The strong backscattered signal from aerosols in near field region will interfere with the weak atmospheric signal, making the accuracy of Doppler shift estimation deteriorate seriously. Considering the formation mechanism of crosstalk, a solution based on adaptive field of view (FOV) modulation is proposed to suppress the crosstalk which is validated by numerical simulation and experiment. Dynamic range of the backscatter intensity is controlled from 10 dB to 2 dB within the distance of 50 m to 300 m, thus the crosstalk is accordingly suppressed.

13.
Int J Mol Sci ; 23(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36077355

RESUMO

Salt stress has a serious impact on normal plant growth and yield. Carotenoid cleavage dioxygenase (CCD) degrades carotenoids to produce apocarotenoids, which are involved in plant responses to biotic and abiotic stresses. This study shows that the expression of sweet potato IbCCD4 was significantly induced by salt and dehydration stress. The heterologous expression of IbCCD4 in Arabidopsis was induced to confirm its salt tolerance. Under 200 mM NaCl treatment, compared to wild-type plants, the rosette leaves of IbCCD4-overexpressing Arabidopsis showed increased anthocyanins and carotenoid contents, an increased expression of most genes in the carotenoid metabolic pathway, and increased malondialdehyde (MDA) levels. IbCCD4-overexpressing lines also showed a decreased expression of resistance-related genes and a lower activity of three antioxidant enzymes: peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT). These results indicate that IbCCD4 reduced salt tolerance in Arabidopsis, which contributes to the understanding of the role of IbCCD4 in salt stress.


Assuntos
Arabidopsis , Dioxigenases , Ipomoea batatas , Antocianinas/metabolismo , Arabidopsis/metabolismo , Carotenoides/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Regulação da Expressão Gênica de Plantas , Ipomoea batatas/genética , Ipomoea batatas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Tolerância ao Sal/genética , Estresse Fisiológico/genética
14.
Biochem Biophys Res Commun ; 555: 175-181, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33819748

RESUMO

Microgravity and radiation exposure-induced bone damage is one of the most significant alterations in astronauts after long-term spaceflight. However, the underlying mechanism is still largely unknown. Recent ground-based simulation studies have suggested that this impairment is likely mediated by increased production of reactive oxygen species (ROS) during spaceflight. The small Maf protein MafG is a basic-region leucine zipper-type transcription factor, and it globally contributes to regulation of antioxidant and metabolic networks. Our research investigated the role of MafG in the process of apoptosis induced by simulated microgravity and radiation in MC3T3-E1 cells. We found that simulated microgravity or radiation alone decreased MafG expression and elevated apoptosis in MC3T3-E1 cells, and combined simulated microgravity and radiation treatment aggravated apoptosis. Meanwhile, under normal conditions, increased ROS levels facilitated apoptosis and downregulated the expression of MafG in MC3T3-E1 cells. Overexpression of MafG decreased apoptosis induced by simulated microgravity and radiation. These findings provide new insight into the mechanism of bone damage induced by microgravity and radiation during space flight.


Assuntos
Apoptose/efeitos da radiação , Fator de Transcrição MafG/metabolismo , Osteoblastos/citologia , Osteoblastos/efeitos da radiação , Proteínas Repressoras/metabolismo , Apoptose/fisiologia , Linhagem Celular , Regulação para Baixo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Fator de Transcrição MafG/genética , Osteoblastos/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas Repressoras/genética , Simulação de Ausência de Peso , Raios X
15.
Brain Topogr ; 34(6): 731-744, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34652579

RESUMO

To evaluate the relationship between the network metrics of 68 brain regions and duration of temporal lobe epilepsy (TLE). Magnetoencephalography (MEG) data from 53 patients with TLE (28 left TLE, 25 right TLE) were recorded between seizures at resting state and analyzed in six frequency bands: delta (0.1-4 Hz), theta (4-8 Hz), lower alpha (8-10 Hz), upper alpha (10-13 Hz), beta (13-30 Hz), and lower gamma (30-48 Hz). Three local network metrics, betweenness centrality, nodal degree, and nodal efficiency, were chosen to analyze the functional brain network. In Left, Right, and All (Left + Right) TLE groups, different metrics provide significant positive or negative correlations with the duration of TLE, in different frequency bands, and in different brain regions. In the Left TLE group, significant correlation between TLE duration and metric exists in the delta, beta, or lower gamma band, with network betweenness centrality, nodal degree, or nodal efficiency, in left caudal middle frontal, left middle temporal, or left supramarginal. In the Right TLE group, significant correlation exists in lower gamma or delta band, with nodal degree, or nodal efficiency, in left precuneus or right temporal pole. In the All TLE group, the significant correlation exists in delta, theta, beta, or lower gamma band, with nodal degree, or betweenness centrality, in either left or right hemisphere. Network metrics for some specific brain regions changed in patients with TLE as the duration of their TLE increased. Further researching these changes may be important for studying the pathogenesis, presurgical evaluation, and clinical treatment of long-term TLE.


Assuntos
Epilepsia do Lobo Temporal , Magnetoencefalografia , Benchmarking , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Epilepsia do Lobo Temporal/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
16.
Nano Lett ; 20(11): 8319-8325, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33090809

RESUMO

The atomic-level understanding of the dynamic evolution of the surface structure of bimetallic nanoparticles under industrially relevant operando conditions provides a key guide for improving their catalytic performance. Here, we exploit operando X-ray absorption fine structure spectroscopy to determine the dynamic surface reconstruction of Cu/Au bimetallic alloy where single-atom Cu was embedded on the Au nanoparticle, under electrocatalytic conditions. We identify the migration of isolated Cu atoms from the vertex position of the Au nanoparticle to the stable (100) plane of the Au first atom layer, when the reduction potential is applied. Density functional theory calculations reveal that the surface atom migration would significantly modulate the Au electronic structure, thus serving as the real active site for the catalytic performance. These findings demonstrate the real structural change under electrochemical conditions and provide guidance for the rational design of high-activity bimetallic nanocatalysts.

17.
Int J Mol Sci ; 22(19)2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34638868

RESUMO

Mechanical unloading contributes to significant cardiovascular deconditioning. Endothelial dysfunction in the sites of microcirculation may be one of the causes of the cardiovascular degeneration induced by unloading, but the detailed mechanism is still unclear. Here, we first demonstrated that mechanical unloading inhibited brain microvascular endothelial cell proliferation and downregulated histone deacetylase 6 (HDAC6) expression. Furthermore, HDAC6 promoted microvascular endothelial cell proliferation and attenuated the inhibition of proliferation caused by clinorotation unloading. To comprehensively identify microRNAs (miRNAs) that are regulated by HDAC6, we analyzed differential miRNA expression in microvascular endothelial cells after transfection with HDAC6 siRNA and selected miR-155-5p, which was the miRNA with the most significantly increased expression. The ectopic expression of miR-155-5p inhibited microvascular endothelial cell proliferation and directly downregulated Ras homolog enriched in brain (RHEB) expression. Moreover, RHEB expression was downregulated under mechanical unloading and was essential for the miR-155-5p-mediated promotion of microvascular endothelial cell proliferation. Taken together, these results are the first to elucidate the role of HDAC6 in unloading-induced cell growth inhibition through the miR-155-5p/RHEB axis, suggesting that the HDAC6/miR-155-5p/RHEB pathway is a specific target for the preventative treatment of cardiovascular deconditioning.


Assuntos
Proliferação de Células , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Desacetilase 6 de Histona/metabolismo , MicroRNAs/biossíntese , Microvasos/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Animais , Linhagem Celular , Células Endoteliais/citologia , Camundongos , Microvasos/citologia
18.
Biochem Biophys Res Commun ; 522(1): 164-170, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31757419

RESUMO

Disuse osteoporosis is common in prolonged therapeutic bed rest, space flight and immobilization due to limb fracture, which is related to reduction of mechanical stress on bone. Mechanical unloading can inhibit the differentiation of osteoblasts, but the detailed mechanism is still unclear. Runt-related transcription factor-2 (Runx2), is an important transcription factor, which plays a crucial role in disuse osteoporosis induced by unloading conditions. In this study, we found that Runx2-targeting mechano-sensitive miR-30 family members, miR-30b, miR-30c, miR-30d and miR-30e increased significantly, and were negatively correlated with the expression of Runx2 under unloading condition. Further studies found that the four miRNAs inhibited the expression of Runx2 and osteoblast differentiation under normal loading, and the knockdown of these miRNAs attenuated partly the inhibition of osteoblast differentiation induced by unloading condition in MC3T3-E1 cells. This study is the first to report miR-30 family members can regulate partly the dysfunction of osteoblasts under unloading condition, which is expected to be targets for the treatment of disuse osteoporosis.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core/genética , MicroRNAs/genética , Osteoblastos/citologia , Animais , Diferenciação Celular , Linhagem Celular , Regulação para Baixo , Camundongos , Osteoblastos/metabolismo , Osteogênese , Estresse Mecânico , Regulação para Cima
19.
Phys Chem Chem Phys ; 22(28): 15795-15798, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32453312

RESUMO

A straightforward strategy is developed to improve the injection efficiency of hot electrons in a Ag/TiO2 plasmonic photocatalyst by introducing Fe as a dopant. The Fe dopant energy level formed within the bandgap of TiO2 provides an extra electron transfer channel for transferring the hot electrons induced by plasmonic Ag nanoparticles.

20.
J Environ Sci (China) ; 91: 35-42, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32172980

RESUMO

Much attention has been paid to the pollutant dimethylarsenic acid (DMA), because of its high toxicity even at very low doses. Although TiO2 photocatalytic oxidation (PCO) is one of the few effective methods for treating DMA-containing water, the efficient decomposition of DMA and simultaneous removal of toxic arsenic species remains a significant but challenging task. Here, defective mesoporous TiO2 with mixed-phase structure was synthesized and used as both photocatalyst and adsorbent for DMA removal. Due to the reduced band-gap and enhanced separation of photogenerated charge carriers, the oxygen-deficient TiO2 nanostructures exhibited 4.2 times higher PCO efficiency than commercial TiO2 (P25). More importantly, the high surface area of the mesoporous TiO2 provided sufficient active sites for in-situ adsorption and reaction, resulting in the efficient removal of as-formed As(V). Combining the experimental and characterization results, the different roles of reactive species during PCO reactions were clarified. In the presence of hole (h+) as the dominant oxidation species, DMA was demethylated and transformed into MMA. Thereafter, MMA was subsequently reduced to As(III) by photo-generated electrons. Superoxide radicals (O2•-) played a significant role in oxidizing As(III) into As(V), which was finally adsorptively removed by the mesoporous TiO2.


Assuntos
Ácido Cacodílico , Titânio , Adsorção , Catálise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA