Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nano Lett ; 24(9): 2765-2772, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38393855

RESUMO

Alloying lanthanide ions (Yb3+) into perovskite quantum dots (Yb3+:CsPb(Cl1-xBrx)3) is an effective method to achieve efficient near-infrared (NIR) luminescence (>950 nm). Increasing the Yb3+ alloying ratio in the perovskite matrix enhances the luminescence intensity of Yb3+ emission at 990 nm. However, high Yb3+ alloying (>15%) results in vacancy-induced inferior material stability. In this work, we developed a polarity-mediated antisolvent manipulation strategy to resolve the incompatibility between a high Yb3+ alloying ratio and inferior stability of Yb3+:CsPb(Cl1-xBrx)3. Precise control of solution polarity enables increased uniformity of the perovskite matrix with fewer trap densities. Employing this strategy, we obtain Yb3+:CsPb(Cl1-xBrx)3 with the highest Yb3+ alloying ratio of 30.2% and a 2-fold higher electroluminescence intensity at 990 nm. We lever the engineered Yb3+:CsPb(Cl1-xBrx)3 to fabricate NIR-LEDs, achieving a peak external quantum efficiency (EQE) of 8.5% at 990 nm: this represents the highest among perovskite NIR-LEDs with an emission wavelength above 950 nm.

2.
Eur Spine J ; 33(10): 3949-3956, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39230719

RESUMO

PURPOSE: To investigate the clinical application of zonally magnified oblique multislice (ZOOM) imaging technology in patients with degenerative cervical myelopathy (DCM) and compare it with T2WI imaging. METHODS: A total of 111 patients diagnosed with DCM were recruited. According to mJOA, patients with DCM were divided into ND + group with neurological dysfunction and ND- group without neurological dysfunction. Routine MRI and ZOOM-DWI were performed on 3.0 T MRI to obtain sagittal T2WI and apparent diffusion coefficient (ADC) diagram. ADC values of the narrow segment and its adjacent upper and lower segments were measured, and compared between the ND + and ND- groups. The correlation between ADC value of cervical spinal cord and mJOA score was analyzed. Additionally, ROC curves were plotted to calculate the AUC values. RESULTS: The comparison between ND + and ND- groups shows that there are significant differences in mJOA score, T2WI, anteroposterior diameter of spinal canal, ADC values of narrow, upper and lower segment (P < 0.05). In ND + group, there is a significant difference between ADC values of the narrow and its upper and lower segments (P < 0.001), while with no significant difference in ADC values of the upper and lower segments (P > 0.05). Results of correlation analysis indicate that in the ND + group, neurological dysfunction evaluated by mJOA scores is correlated with increased ADC values of the narrow segment (r = -0.52, P < 0.001), but not significantly correlated with ADC values of the upper and lower segments. Furthermore, T2WI, anteroposterior diameter of the spinal canal, and cervical cord ADC values all has diagnostic efficacy in evaluating neurological dysfunction in DCM (AUC > 0.5, P < 0.05), with the ADC value of the narrow segment being optimal. CONCLUSION: The ADC value of spinal cord obtained by small-field ZOOM-DWI can be used to evaluate neurological dysfunction in DCM, and is superior to traditional T2WI.


Assuntos
Vértebras Cervicais , Imagem de Difusão por Ressonância Magnética , Doenças da Medula Espinal , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Imagem de Difusão por Ressonância Magnética/métodos , Vértebras Cervicais/diagnóstico por imagem , Doenças da Medula Espinal/diagnóstico por imagem , Adulto , Imageamento por Ressonância Magnética/métodos
3.
Chem Biodivers ; : e202401931, 2024 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-39482800

RESUMO

Vascular dementia (VaD) is a neurodegenerative disease resulting from cerebral vascular obstruction, leading to cognitive impairment, and currently lacks effective treatment options. Due to its complex pathogenesis, multi-target drug design (MTDLs) strategies are considered among the most promising therapeutic approaches. In this study, we designed and synthesized a series of novel indanone derivatives targeting targets related to vascular health and dementia. The results indicated that compound C5 exhibited excellent acetylcholinesterase inhibitory activity (IC50 = 1.16 ± 0.41 µM) and anti-platelet aggregation activity (IC50 = 4.92 ± 0.10 µM) within ranges of 0.1-1000 µM and 0.03-300 µM, respectively, possibly mediated by molecular docking interactions. Furthermore, compound C5 demonstrated protective effects on cells at concentrations ≤50 µM, significantly reducing the release of nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1ß) in a concentration-dependent manner, showcasing its potent neuroinflammatory inhibitory effects. Anti-inflammatory therapies are regarded as effective strategies for treating VaD. Therefore, compound C5 holds promise as a novel candidate drug for further investigation into the treatment of vascular dementia.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38536574

RESUMO

While the correlation between parental autonomy granting and adolescents' problematic Internet use (PIU) has been confirmed, the processes underlying this connection have not been thoroughly investigated. Drawing on the ecological systems theory, this study sought to investigate the mediating mechanism of peer attachment and the moderating mechanism of school climate that link parental autonomy granting to PIU. A two-wave longitudinal design was employed with a time interval of six months. The participants were 852 adolescents who attended three middle schools located in Guangdong Province, China. Self-report questionnaires were used to obtain data on demographics, parental autonomy granting, peer attachment, school climate, and PIU. The findings indicated that peer attachment significantly mediated the link between parental autonomy granting and adolescent PIU. A positive school climate significantly moderated the influence of parental autonomy granting on peer attachment and the influence of peer attachment on PIU. Specifically, the association between parental autonomy granting and peer attachment and the association between peer attachment and PIU were more pronounced when the school climate was perceived to be positive. This research underscores the possible significance of peer attachment in the association between parental autonomy granting and PIU and offers valuable insights for mitigating the negative outcomes of PIU.

5.
J Transl Med ; 21(1): 754, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37884960

RESUMO

BACKGROUND: Recent research shows that tumor-associated macrophages (TAMs) are the primary consumers of glucose in tumor tissue, surpassing that of tumor cells. Our previous studies revealed that inhibiting glucose uptake impairs the survival and tumor-promoting function of hypoxic TAMs, suggesting that glucose reduction by energy restriction (calorie restriction or short-term fasting) may has a significant impact on TAMs. The purpose of this study is to verify the effect of fasting-mimicking diet (FMD) on TAMs, and to determine whether FMD synergizes with anti-angiogenic drug apatinib via TAMs. METHODS: The effect of FMD on TAMs and its synergistic effects with apatinib were observed using an orthotopic mouse breast cancer model. An in vitro cell model, utilizing M2 macrophages derived from THP-1 cell line, was intended to assess the effects of low glucose on TAMs under hypoxic and normoxic conditions. Bioinformatics was used to screen for potential mechanisms of action, which were then validated both in vivo and in vitro. RESULTS: FMD significantly inhibit the pro-tumor function of TAMs in vivo and in vitro, with the inhibitory effect being more pronounced under hypoxic conditions. Additionally, the combination of FMD-mediated TAMs inhibition with apatinib results in synergistic anti-tumor activity. This effect is partially mediated by the downregulation of CCL8 expression and secretion by the mTOR-HIF-1α signaling pathway. CONCLUSIONS: These results support further clinical combination studies of FMD and anti-angiogenic therapy as potential anti-tumor strategies.


Assuntos
Inibidores da Angiogênese , Macrófagos Associados a Tumor , Animais , Camundongos , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Hipóxia , Jejum , Dieta , Glucose , Microambiente Tumoral , Linhagem Celular Tumoral
6.
Chem Biodivers ; 20(2): e202200897, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36631429

RESUMO

Quercetin is a kind of polyphenolic flavonoid compounds which has perfect antioxidant properties. However, quercetin is not available in many situations due to its poor bioavailability. In this work, the QAEs with better solubility and even stronger antioxidant properties were synthesized, through the esterification between quercetin and the chlorinated cinnamic acid or its derivatives, whose chlorination were achieved by using SOCl2 . The protective effects of the QAEs were evaluated by the H2 O2 -induced apoptosis experiment in rat adrenal pheochromocytoma cells (PC12 cells) and its ability to remove ROS generated by oxidative stress. Compared with the original quercetin group, the QAEs groups showed much improved cell viability and capability of removing ROS, which means their higher bioavailability than the parent.


Assuntos
Antioxidantes , Quercetina , Ratos , Animais , Quercetina/farmacologia , Antioxidantes/farmacologia , Espécies Reativas de Oxigênio , Células PC12 , Ésteres/farmacologia , Estresse Oxidativo
7.
Angew Chem Int Ed Engl ; 62(46): e202311089, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37770413

RESUMO

Resurfacing perovskite nanocrystals (NCs) with tight-binding and conductive ligands to resolve the dynamic ligands-surface interaction is the fundamental issue for their applications in perovskite light-emitting diodes (PeLEDs). Although various types of surface ligands have been proposed, these ligands either exhibit weak Lewis acid/base interactions or need high polar solvents for dissolution and passivation, resulting in a compromise in the efficiency and stability of PeLEDs. Herein, we report a chemically reactive agent (Iodotrimethylsilane, TMIS) to address the trade-off among conductivity, solubility and passivation using all-inorganic CsPbI3 NCs. The liquid TMIS ensures good solubility in non-polar solvents and reacts with oleate ligands and produces in situ HI for surface etching and passivation, enabling strong-binding ligands on the NCs surface. We report, as a result, red PeLEDs with an external quantum efficiency (EQE) of ≈23 %, which is 11.2-fold higher than the control, and is among the highest CsPbI3 PeLEDs. We further demonstrate the universality of this ligand strategy in the pure bromide system (CsPbBr3 ), and report EQE of ≈20 % at 640, 652, and 664 nm. This represents the first demonstration of a chemically reactive ligand strategy that applies to different systems and works effectively in red PeLEDs spanning emission from pure-red to deep-red.

8.
Lab Invest ; 99(8): 1143-1156, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30911150

RESUMO

Acute respiratory distress syndrome (ARDS) is a uniform progression of overwhelming inflammation in lung tissue with extensive infiltration of inflammatory cells. Neutrophil apoptosis is thought to be a significant process in the control of the resolution phase of inflammation. It has been proved that 5-Aza-2'-deoxycytidine (Aza) can inhibit cancer by activating death-associated protein kinase 1 (DAPK1) to promote apoptosis. However, the effect of DAPK1 on neutrophil apoptosis is unclear, and research on the role of Aza in inflammation is lacking. Here, we investigated whether Aza can regulate DAPK1 expression to influence the fate of neutrophils in ARDS. In vitro, we stimulated neutrophil-like HL-60 (dHL-60) cells with different concentrations of Aza for different durations and used RNA interference to up- or downregulate DAPK1 expression. We observed that culturing dHL-60 cells with Aza increased apoptosis by inhibiting NF-κB activation to modulate the expression of Bcl-2 family proteins, which was closely related to the levels of DAPK1. In vivo, ARDS was evoked by intratracheal instillation of lipopolysaccharide (LPS; 3 mg/kg). One hour after LPS administration, mice were treated with Aza (1 mg/kg, i.p.). To inhibit DAPK1 expression, mice were intraperitoneally injected with a DAPK1 inhibitor. Aza treatment accelerated inflammatory resolution in LPS-induced ARDS by suppressing pulmonary edema, alleviating lung injury and decreasing the infiltration of inflammatory cells in bronchoalveolar lavage fluid (BALF). Moreover, Aza reduced the production of proinflammatory cytokines. However, administration of the DAPK1 inhibitor attenuated the protective effects of Aza. Similarly, the proapoptotic function of Aza was prevented when DAPK1 was inhibited either in vivo or in vitro. In summary, Aza promotes neutrophil apoptosis by activating DAPK1 to accelerate inflammatory resolution in LPS-induced ARDS. This study provides the first evidence that Aza prevents LPS-induced neutrophil survival by modulating DAPK1 expression.


Assuntos
Apoptose/efeitos dos fármacos , Proteínas Quinases Associadas com Morte Celular , Inflamação/metabolismo , Neutrófilos/efeitos dos fármacos , Síndrome do Desconforto Respiratório/metabolismo , Animais , Citocinas/metabolismo , Proteínas Quinases Associadas com Morte Celular/metabolismo , Proteínas Quinases Associadas com Morte Celular/farmacologia , Decitabina/metabolismo , Decitabina/farmacologia , Modelos Animais de Doenças , Células HL-60 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
9.
Hepatology ; 65(4): 1206-1221, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27809333

RESUMO

Great progress has been achieved in the study of Hippo signaling in regulating tumorigenesis; however, the downstream molecular events that mediate this process have not been completely defined. Moreover, regulation of Hippo signaling during tumorigenesis in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we systematically investigated the relationship between Yes-associated protein/TEA domain family member (YAP-TEAD) and hepatocyte nuclear factor 4-alpha (HNF4α) in the hepatocarcinogenesis of HCC cells. Our results indicated that HNF4α expression was negatively regulated by YAP1 in HCC cells by a ubiquitin proteasome pathway. By contrast, HNF4α was found to directly associate with TEAD4 to compete with YAP1 for binding to TEAD4, thus inhibiting the transcriptional activity of YAP-TEAD and expression of their target genes. Moreover, overexpression of HNF4α was found to significantly compromise YAP-TEAD-induced HCC cell proliferation and stem cell expansion. Finally, we documented the regulatory mechanism between YAP-TEAD and HNF4α in rat and mouse tumor models, which confirmed our in vitro results. CONCLUSION: There is a double-negative feedback mechanism that controls TEAD-YAP and HNF4α expression in vitro and in vivo, thereby regulating cellular proliferation and differentiation. Given that YAP acts as a dominant oncogene in HCC and plays a crucial role in stem cell homeostasis and tissue regeneration, manipulating the interaction between YAP, TEADs, and HNF4α may provide a new approach for HCC treatment and regenerative medicine. (Hepatology 2017;65:1206-1221).


Assuntos
Carcinoma Hepatocelular/genética , Fator 4 Nuclear de Hepatócito/genética , Neoplasias Hepáticas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Biópsia por Agulha , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas de Ligação a DNA/genética , Modelos Animais de Doenças , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfoproteínas/genética , Distribuição Aleatória , Ratos , Ratos Wistar , Sensibilidade e Especificidade , Transdução de Sinais , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/genética , Proteínas de Sinalização YAP
10.
Gastroenterology ; 150(3): 659-671.e16, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26619963

RESUMO

BACKGROUND & AIMS: Activation of WNT signaling promotes the invasive activities of several types of cancer cells, but it is not clear if it regulates the same processes in colorectal cancer (CRC) cells, or what mechanisms are involved. We studied the expression and function of OVOL2, a member of the Ovo family of conserved zinc-finger transcription factors regulated by the WNT signaling pathway, in intestinal tumors of mice and human beings. METHODS: We analyzed the expression of OVOL2 protein and messenger RNA in CRC cell lines and tissue arrays, as well as CRC samples from patients who underwent surgery at Xiamen University in China from 2009 to 2012; clinical information also was collected. CRC cell lines (SW620) were infected with lentivirus expressing OVOL2, analyzed in migration and invasion assays, and injected into nude mice to assess tumor growth and metastasis. Tandem affinity purification was used to purify the OVOL2-containing complex from CRC cells; the complex was analyzed by liquid chromatography, tandem mass spectrometry, and immunoprecipitation experiments. Gene promoter activities were measured in luciferase reporter assays. We analyzed mice with an intestine-specific disruption of Ovol2 (Ovol2(flox/+) transgenic mice), as well as Apc(min/+) mice; these mice were crossed and analyzed. RESULTS: Analysis of data from patients indicated that the levels of OVOL2 messenger RNA were significantly lower in colon carcinomas than adenomas, and decreased significantly as carcinomas progressed from grades 2 to 4. Immunohistochemical analysis of a tissue array of 275 CRC samples showed a negative association between tumor stage and OVOL2 level. Overexpression of OVOL2 in SW620 cells decreased their migration and invasion, reduced markers of the epithelial-to-mesenchymal transition, and suppressed their metastasis as xenograft tumors in nude mice; knockdown of OVOL2 caused LS174T cells to transition from epithelial to mesenchymal phenotypes. OVOL2 bound T-cell factor (TCF)4 and ß-catenin, facilitating recruitment of histone deacetylase 1 to the TCF4-ß-catenin complex; this inhibited expression of epithelial-to-mesenchymal transition-related genes regulated by WNT, such as SLUG, in CRC cell lines. OVOL2 was a downstream target of WNT signaling in LS174T and SW480 cells. The OVOL2 promoter was hypermethylated in late-stage CRC specimens from patients and in SW620 cells; hypermethylation resulted in OVOL2 down-regulation and an inability to inhibit WNT signaling. Disruption of Ovol2 in Apc(min/+) mice increased WNT activity in intestinal tissues and the formation of invasive intestinal tumors. CONCLUSIONS: OVOL2 is a colorectal tumor suppressor that blocks WNT signaling by facilitating the recruitment of histone deacetylase 1 to the TCF4-ß-catenin complex. Strategies to increase levels of OVOL2 might be developed to reduce colorectal tumor progression and metastasis.


Assuntos
Movimento Celular , Neoplasias Colorretais/metabolismo , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Células CACO-2 , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Regulação para Baixo , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Genótipo , Células HCT116 , Células HEK293 , Histona Desacetilase 1/metabolismo , Humanos , Estimativa de Kaplan-Meier , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Camundongos Transgênicos , Invasividade Neoplásica , Metástase Neoplásica , Fenótipo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Fatores de Tempo , Fator de Transcrição 4 , Fatores de Transcrição/genética , Transfecção , Carga Tumoral , beta Catenina/metabolismo
11.
Int J Syst Evol Microbiol ; 67(10): 3739-3743, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28884674

RESUMO

The Gram-stain-negative, rod-shaped, strictly aerobic, motile bacterial strain, designated YM155T, was isolated from a seamount near the Yap Trench in the tropical western Pacific. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain YM155T was related to the genus Thalassotalea and had highest 16S rRNA gene sequence similarities with the type strains of Thalassotalea piscium T202T (97.2 %) and Thalassotalea agariperforans M-M1T (97.2 %). The predominant cellular fatty acids were C17 : 1ω8c, summed feature 3 (composed of iso-C15 : 0 2-OH and/or C16 : 1ω7c) and iso-C16 : 0. Ubiquinone 8 (Q-8) was the respiratory quinone. The polar lipid profile contained phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and one unidentified lipid. The genomic DNA G+C content of strain YM155T was 36.1 mol%. On the basis of the evidence presented in this study, strain YM155T represents a novel species of the genus Thalassotalea, for which we propose the name Thalassotalea profundi sp. nov. (type strain YM155T=KACC 18563T=CGMCC 1.15922T).


Assuntos
Gammaproteobacteria/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Oceano Pacífico , Fosfatidilgliceróis/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
12.
Int J Syst Evol Microbiol ; 67(6): 1996-2000, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28629507

RESUMO

A Gram-stain-negative, rod-shaped, strictly aerobic, motile bacterial strain, designated YM319T, was isolated from a seamount near the Yap Trench in the tropical western Pacific. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain YM319T was related to the genus Oceanisphaera and had highest 16S rRNA gene sequence similarities with the type strains Oceanisphaera profunda SM1222T (97.4 %), Oceanisphaera sediminis TW92T (97.3 %) and Oceanisphaera ostreae T-w6T (97.1 %). The predominant cellular fatty acids were summed feature 3 (composed of iso-C15 : 0 2-OH and/or C16 : 1 ω7c), C16 : 0 and C18 : 1ω7c. Strain YM319T had Q-8 as the predominant ubiquinone. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid and four unidentified lipids. The genomic DNA G+C content of strain YM319T was 54.8 mol%. On the basis of the evidence presented in this study, strain YM319T represents a novel species of the genus Oceanisphaera, for which we propose the name Oceanisphaera marina sp. nov. (type strain YM319T=KACC 18564T=CGMCC 1.15923T).


Assuntos
Aeromonadaceae/classificação , Filogenia , Água do Mar/microbiologia , Aeromonadaceae/genética , Aeromonadaceae/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oceano Pacífico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
13.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 39(5): 602-610, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29125100

RESUMO

Objective To observe the effects of force signals and inflammatory cytokines on the expressions of functional proteins during the differentiation of periodontal ligament cells(PDLCs) into osteoclasts. Methods The caries-free premolars that needed to be removed for orthodontic treatment were collected,human periodontal ligament cells were cultured in vitro.Human PDLCs were exposed to inflammatory cytokines including interleukin(IL)-1ß,-6,-23,and tumor necrosis factor alpha(TNF-α). Cyclicmechanical tension with a maximum 5% elongation for different durations(0,2,4,8,12,and 24 hours) were applied. Then the expressions of signaling molecules related to osteoclastogenesis(OPG) and receptor activated nuclear factor κB ligand(RANKL) were determined at protein levels by Western blotting. Results Inflammatory cytokines improved the expressions of osteoclastgenesis regulators in hPDLCs,while cyclic-tension force reduced their expressions. However,the combined effect of inflammatory cytokines and cyclic-tension force resulted in high expressions of osteoclastgenesis regulators. Conclusion Inflammatory cytokines can promote the expressions of the osteoclastgenic factors,which can not be offset by cyclic-tension force.


Assuntos
Interleucinas/farmacologia , Osteoclastos/citologia , Osteogênese , Ligamento Periodontal/citologia , Estresse Mecânico , Fator de Necrose Tumoral alfa/farmacologia , Diferenciação Celular , Células Cultivadas , Humanos , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo
14.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 38(1): 22-6, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26956851

RESUMO

OBJECTIVE: To investigate the expression and effect of Connexin43 (Cx43) on tensile tension-stimulated osteogenic transcription factors of human periodontal ligament fibroblasts (hPDLFs). METHODS: After hPDLFs were treated with 5% elongation tension for 1 h, 2 h, 4 h, 8 h, and 24 h, we examined the expressions of Cx43, Osterix, and RUNX2 at the mRNA level. After Cx43 expression was suppressed by siRNA or 18α-GA, the changes The mRNA in hPDLFs of Osterix and RUNX2 were observed. RESULTS: The expressions of Cx43, Osterix, and RUNX2 mRNA in hPDLFs increased in a time-dependent fashion following tensile strain (all P<0.05), with the highest level at 5% elongation for 24 h. After Cx43 expression was blocked by two different methods, the increasing expressions of Osterix and RUNX2 were inhibited. CONCLUSIONS: 5% cyclic tension upregulates Cx43 expression and promotes the expression of Osterix and RUNX2 in a time-dependent manner. Cx43 may be involved in the osteogenic response of hPDLFs to mechanical tension.


Assuntos
Fibroblastos , Ligamento Periodontal , Células Cultivadas , Conexina 43 , Ácido Glicirretínico/análogos & derivados , Humanos , Osteogênese , RNA Mensageiro , RNA Interferente Pequeno , Estresse Mecânico , Fatores de Transcrição , Regulação para Cima
15.
J Cell Sci ; 126(Pt 24): 5692-703, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24101726

RESUMO

Wnt-ß-catenin signaling participates in the epithelial-mesenchymal transition (EMT) in a variety of cancers; however, its involvement in hepatocellular carcinoma (HCC) and downstream molecular events is largely undefined. HNF4α is the most prominent and specific factor maintaining the differentiation of hepatic lineage cells and a potential EMT regulator in HCC cells. However, the molecular mechanisms by which HNF4α maintains the differentiated liver epithelium and inhibits EMT have not been completely defined. In this study, we systematically explored the relationship between Wnt-ß-catenin signaling and HNF4α in the EMT process of HCC cells. Our results indicated that HNF4α expression was negatively regulated during Wnt-ß-catenin signaling-induced EMT through Snail and Slug in HCC cells. In contrast, HNF4α was found to directly associate with TCF4 to compete with ß-catenin but facilitate transcription co-repressor activities, thus inhibiting expression of EMT-related Wnt-ß-catenin targets. Moreover, HNF4α may control the switch between the transcriptional and adhesion functions of ß-catenin. Overexpression of HNF4α was found to completely compromise the Wnt-ß-catenin-signaling-induced EMT phenotype. Finally, we determined the regulation pattern between Wnt-ß-catenin signaling and HNF4α in rat tumor models. Our studies have identified a double-negative feedback mechanism controlling Wnt-ß-catenin signaling and HNF4α expression in vitro and in vivo, which sheds new light on the regulation of EMT in HCC. The modulation of these molecular processes may be a method of inhibiting HCC invasion by blocking Wnt-ß-catenin signaling or restoring HNF4α expression to prevent EMT.


Assuntos
Carcinoma Hepatocelular/metabolismo , Fator 4 Nuclear de Hepatócito/metabolismo , Neoplasias Hepáticas Experimentais/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Transição Epitelial-Mesenquimal , Retroalimentação Fisiológica , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Neoplasias Hepáticas Experimentais/patologia , Masculino , Ligação Proteica , Ratos , Ratos Wistar , Fatores de Transcrição da Família Snail , Fator de Transcrição 4 , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo
16.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 36(6): 675-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25556745

RESUMO

With the improvement of living standards and oral health awareness in people and with the development of the techniques in orthodontic therapy,the number of adult patients in orthodontics is gradually increasing. Due to adults' social occupations,psychological factors,complicated intraoral status,these factors make adult patients differences from adolescents. In this paper,the problems related with adult orthodontic treatment were reviewed.


Assuntos
Ortodontia Corretiva , Adolescente , Adulto , Humanos , Má Oclusão/terapia
17.
Sci Rep ; 14(1): 6251, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38491037

RESUMO

The core of many cryptocurrencies is the decentralised validation network operating on proof-of-work technology. In these systems, validation is done by so-called miners who can digitally sign blocks once they solve a computationally-hard problem. Conventional wisdom generally considers this protocol as secure and stable as miners are incentivised to follow the behaviour of the majority. However, whether some strategic mining behaviours occur in practice is still a major concern. In this paper we target this question by focusing on a security threat: a selfish mining attack in which malicious miners deviate from protocol by not immediately revealing their newly mined blocks. We propose a statistical test to analyse each miner's behaviour in five popular cryptocurrencies: Bitcoin, Litecoin, Monacoin, Ethereum and Bitcoin Cash. Our method is based on the realisation that selfish mining behaviour will cause identifiable anomalies in the statistics of miner's successive blocks discovery. Secondly, we apply heuristics-based address clustering to improve the detectability of this kind of behaviour. We find a marked presence of abnormal miners in Monacoin and Bitcoin Cash, and, to a lesser extent, in Ethereum. Finally, we extend our method to detect coordinated selfish mining attacks, finding mining cartels in Monacoin where miners might secretly share information about newly mined blocks in advance. Our analysis contributes to the research on security in cryptocurrency systems by providing the first empirical evidence that the aforementioned strategic mining behaviours do take place in practice.

18.
Shanghai Kou Qiang Yi Xue ; 33(1): 6-12, 2024 Feb.
Artigo em Zh | MEDLINE | ID: mdl-38583018

RESUMO

PURPOSE: Bioactive magnesium ions were successfully incorporated into the nanoporous titanium base coating by micro-arc oxidation(MAO), and its physical properties and osteogenic effects were explored. METHODS: Non-magnesium-containing and magnesium-containing titanium porous titanium coatings(MAO, MAO-mg) were prepared by changing the composition of MAO electrolyte and controlling the doping of magnesium in porous titanium coatings. The samples were characterized by scanning electron microscope (SEM), roughness, contact angle and energy dispersive X-ray spectrometer (EDS). Mg2+ release ability of magnesium-doped nanoporous titanium coatings was determined by inductively coupled plasma/optical emission spectrometer(ICP-OES). The structure of the cytoskeleton was determined by live/dead double staining, CCK-8 detection of material proliferation-toxicity, and staining of ß-actin using FITC-phalloidin. The effects of the coating on osteogenic differentiation in vitro were determined by alizarin red (ARS), alkaline phosphatase (ALP) staining and real-time polymerase chain reaction (qRT-PCR). SPSS 25.0 software package was used for statistical analysis. RESULTS: The MAO electrolyte with magnesium ions did not change the surface characteristics of the porous titanium coating. Each group prepared by MAO had similar microporous structure(P>0.05). There was no significant difference in surface roughness and contact angle between MAO treatment group (MAO, MAO-mg)(P>0.05), but significantly higher than that of Ti group (P<0.05). With the passage of cell culture time, MAO-mg group promoted cell proliferation (P<0.05). MAO-mg group was significantly higher than other groups in ALP and ARS staining. The expression of Runx2 mRNA (P<0.05), ALP(P<0.05) and osteocalcin OCN(P<0.05) in MAO-mg group was significantly higher than that in Ti and MAO groups. CONCLUSIONS: MAO successfully prepared magnesium-containing nanoporous titanium coating, and showed a significant role in promoting osteogenic differentiation.


Assuntos
Nanoporos , Titânio , Titânio/farmacologia , Magnésio/química , Magnésio/farmacologia , Osteogênese/genética , Eletrólitos/farmacologia , Íons/farmacologia , Propriedades de Superfície , Materiais Revestidos Biocompatíveis/farmacologia , Materiais Revestidos Biocompatíveis/química
19.
Gene ; 896: 148033, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38013127

RESUMO

In the entire world, hepatocellular carcinoma (HCC) is one of the most frequent cancers that lead to death. Experiments on the function of long non-coding RNAs in the emergence of malignancies, including HCC, are ongoing. As a crucial RNA monitoring mechanism in eucaryotic cells, nonsense-mediated mRNA decay (NMD) can recognize and destroy mRNAs, which has an premature termination codons (PTC) in the open reading frame to prevent harmful buildup of truncated protein products in the cells. Nonsense transcript regulator 1 (Up-frameshift suppressor 1, UPF1), as a highly conserved RNA helicase and ATPase, plays a key role in NMD. Our laboratory screened out the highly expressed lncRNA LINC02561 in HCC from the TCGA database. Further research found that LINC02561 enhanced the invasion and transition abilities of liver cancer cells by regulating the protein N-Myc downstream regulated 1 (NDRG1). Hypoxia inducible factor-1 (HIF-1α) can bonded to LINC02561 promoters under hypoxic conditions, thereby promoting the upregulation of LINC02561 expression in liver cancer cells. LINC02561 competes with NDRG1 mRNA to bind UPF1, thereby preventing the degradation of NDRG1 mRNA to facilitate NDRG1 protein level. Taken together, the HIF1α-LINC02561-UPF1-NDRG1 regulatory axis could be an entirely novel target of liver cancer-related treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Transativadores/genética , Neoplasias Hepáticas/genética , RNA Helicases/genética , RNA Helicases/metabolismo , Degradação do RNAm Mediada por Códon sem Sentido , Códon sem Sentido
20.
Int J Biol Macromol ; 277(Pt 4): 134459, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39111471

RESUMO

Water stress, a significant abiotic stressor, significantly hampers crop growth and yield, posing threat to food security. Despite the promising potential of nanoparticles (NPs) in enhancing plant stress tolerance, the precise mechanisms underlying the alleviation of water stress using O-Carboxymethyl chitosan nanoparticles (O-CMC-NPs) in maize remain elusive. In this study, we synthesized O-CMC-NPs and delved into their capacity to mitigate water stress (waterlogging and drought) in maize seedlings. Structural characterization revealed spherical O-CMC-NPs with a size of approximately 200 nm. These NPs accumulated near the seed embryo and root tip, resulting in a substantial increase in fresh and dry weights. The application of O-CMC-NPs to water-stressed maize seedlings remarkedly elevated the chlorophyll content and activity of various antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and polyphenol oxidase (PPO). The malondialdehyde (MDA) content was significantly reduced compared to the untreated control. Additionally, the expression of stress-responsive genes, such as ZmSOD, ZmCAT, ZmPOD, ZmTIFY, ZmACO, ZmPYL2, ZmNF-YC12, and ZmEREB180, were significantly upregulated in the O-CMC-NPs treated seedlings. These findings unveil the novel role of O-CMC-NPs in enhancing plant stress tolerance, suggesting their potential application in safeguarding maize seedlings under water stress conditions and facilitating the recovery from oxidative damage.


Assuntos
Quitosana , Nanopartículas , Plântula , Zea mays , Zea mays/efeitos dos fármacos , Zea mays/metabolismo , Quitosana/análogos & derivados , Quitosana/química , Quitosana/farmacologia , Nanopartículas/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Água/química , Antioxidantes/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Desidratação , Proteínas de Plantas/metabolismo , Clorofila/metabolismo , Malondialdeído/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA