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1.
Cell ; 163(3): 670-83, 2015 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-26496607

RESUMO

Ethylene is a gaseous phytohormone that plays vital roles in plant growth and development. Previous studies uncovered EIN2 as an essential signal transducer linking ethylene perception on ER to transcriptional regulation in the nucleus through a "cleave and shuttle" model. In this study, we report another mechanism of EIN2-mediated ethylene signaling, whereby EIN2 imposes the translational repression of EBF1 and EBF2 mRNA. We find that the EBF1/2 3' UTRs mediate EIN2-directed translational repression and identify multiple poly-uridylates (PolyU) motifs as functional cis elements of 3' UTRs. Furthermore, we demonstrate that ethylene induces EIN2 to associate with 3' UTRs and target EBF1/2 mRNA to cytoplasmic processing-body (P-body) through interacting with multiple P-body factors, including EIN5 and PABs. Our study illustrates translational regulation as a key step in ethylene signaling and presents mRNA 3' UTR functioning as a "signal transducer" to sense and relay cellular signaling in plants. VIDEO ABSTRACT.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas , Receptores de Superfície Celular/metabolismo , Proteínas de Arabidopsis/genética , Exorribonucleases/metabolismo , Proteínas F-Box/genética , Conformação de Ácido Nucleico , Proteínas de Plantas/metabolismo , Biossíntese de Proteínas , RNA Mensageiro/química , RNA Mensageiro/metabolismo
2.
Nature ; 620(7976): 994-1000, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37290482

RESUMO

All-perovskite tandem solar cells promise higher power-conversion efficiency (PCE) than single-junction perovskite solar cells (PSCs) while maintaining a low fabrication cost1-3. However, their performance is still largely constrained by the subpar performance of mixed lead-tin (Pb-Sn) narrow-bandgap (NBG) perovskite subcells, mainly because of a high trap density on the perovskite film surface4-6. Although heterojunctions with intermixed 2D/3D perovskites could reduce surface recombination, this common strategy induces transport losses and thereby limits device fill factors (FFs)7-9. Here we develop an immiscible 3D/3D bilayer perovskite heterojunction (PHJ) with type II band structure at the Pb-Sn perovskite-electron-transport layer (ETL) interface to suppress the interfacial non-radiative recombination and facilitate charge extraction. The bilayer PHJ is formed by depositing a layer of lead-halide wide-bandgap (WBG) perovskite on top of the mixed Pb-Sn NBG perovskite through a hybrid evaporation-solution-processing method. This heterostructure allows us to increase the PCE of Pb-Sn PSCs having a 1.2-µm-thick absorber to 23.8%, together with a high open-circuit voltage (Voc) of 0.873 V and a high FF of 82.6%. We thereby demonstrate a record-high PCE of 28.5% (certified 28.0%) in all-perovskite tandem solar cells. The encapsulated tandem devices retain more than 90% of their initial performance after 600 h of continuous operation under simulated one-sun illumination.

3.
Mol Med ; 30(1): 34, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448811

RESUMO

BACKGROUND: Imbalance in energy regulation is a major cause of insulin resistance and diabetes. Melanocortin-4 receptor (MC4R) signaling at specific sites in the central nervous system has synergistic but non-overlapping functions. However, the mechanism by which MC4R in the arcuate nucleus (ARC) region regulates energy balance and insulin resistance remains unclear. METHODS: The MC4Rflox/flox mice with proopiomelanocortin (POMC) -Cre mice were crossed to generate the POMC-MC4Rflox/+ mice. Then POMC-MC4Rflox/+ mice were further mated with MC4Rflox/flox mice to generate the POMC-MC4Rflox/flox mice in which MC4R is selectively deleted in POMC neurons. Bilateral injections of 200 nl of AAV-sh-Kir2.1 (AAV-sh-NC was used as control) were made into the ARC of the hypothalamus. Oxygen consumption, carbon dioxide production, respiratory exchange ratio and energy expenditure were measured by using the CLAMS; Total, visceral and subcutaneous fat was analyzed using micro-CT. Co-immunoprecipitation assays (Co-IP) were used to analyze the interaction between MC4R and Kir2.1 in GT1-7 cells. RESULTS: POMC neuron-specific ablation of MC4R in the ARC region promoted food intake, impaired energy expenditure, leading to increased weight gain and impaired systemic glucose homeostasis. Additionally, MC4R ablation reduced the activation of POMC neuron, and is not tissue-specific for peripheral regulation, suggesting the importance of its central regulation. Mechanistically, sequencing analysis and Co-IP assay demonstrated a direct interaction of MC4R with Kir2.1. Knockdown of Kir2.1 in POMC neuron-specific ablation of MC4R restored the effect of MC4R ablation on energy expenditure and systemic glucose homeostasis, indicating by reduced body weight and ameliorated insulin resistance. CONCLUSION: Hypothalamic POMC neuron-specific knockout of MC4R affects energy balance and insulin sensitivity by regulating Kir2.1. Kir2.1 represents a new target and pathway that could be targeted in obesity.


Assuntos
Resistência à Insulina , Animais , Camundongos , Glucose , Hipotálamo , Resistência à Insulina/genética , Neurônios , Pró-Opiomelanocortina/genética , Receptor Tipo 4 de Melanocortina/genética
4.
J Gene Med ; 26(1): e3637, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37994492

RESUMO

BACKGROUND: In breast cancer (BC), homologous recombination defect (HRD) is a common carcinogenic mechanism. It is meaningful to classify BC according to HRD biomarkers and to develop a platform for identifying BC molecular features, pathological features and therapeutic responses. METHODS: In total, 109 HRD genes were collected and screened by univariate Cox regression analysis to determine the prognostic genes, which were used to construct a consensus matrix to identify BC subtype. Differentially expressed genes (DEGs) were filtered by the Limma package and screened by random forest analysis to build a model to analyze the immunotherapy response and sensitivity and prognosis of patients suffering from BC to different drugs. RESULTS: Thirteen out of 109 HRD genes were prognostic genes of BC, and BC was classified into two subgroups based on their expression. Cluster 1 had a significantly backward survival outcome and a significantly higher adaptive immunity score relative to cluster 2. Six genes were identified by random forest analysis as factors for developing the model. The model provided a prediction called risk score, which showed a significant stratification effect on BC prognosis, immunotherapy response and IC50 values of 62 drugs. CONCLUSIONS: In the present study, two HRD subtypes of BC were successfully identified, for which mutation and immunological features were determined. A model based on differential genes of HRD subtypes was established, which was a potential predictor of prognosis, immunotherapy response and drug sensitivity of BC.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Imunoterapia , Expressão Gênica , Recombinação Homóloga/genética , Mutação
5.
Cancer Cell Int ; 23(1): 316, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38066643

RESUMO

BACKGROUND: Gliomas, a prevalent form of primary brain tumors, are linked with a high mortality rate and unfavorable prognoses. Disulfidptosis, an innovative form of programmed cell death, has received scant attention concerning disulfidptosis-related lncRNAs (DRLs). The objective of this investigation was to ascertain a prognostic signature utilizing DRLs to forecast the prognosis and treatment targets of glioma patients. METHODS: RNA-seq data were procured from The Cancer Genome Atlas database. Disulfidptosis-related genes were compiled from prior research. An analysis of multivariate Cox regression and the least absolute selection operator was used to construct a risk model using six DRLs. The risk signature's performance was evaluated via Kaplan-Meier survival curves and receiver operating characteristic curves. Additionally, functional analysis was carried out using GO, KEGG, and single-sample GSEA to investigate the biological functions and immune infiltration. The research also evaluated tumor mutational burden, therapeutic drug sensitivity, and consensus cluster analysis. Reverse transcription quantitative PCR was conducted to validate the expression level of DRLs. RESULTS: A prognostic signature comprising six DRLs was developed to predict the prognosis of glioma patients. High-risk patients had significantly shorter overall survival than low-risk patients. The robustness of the risk model was validated by receiver operating characteristic curves and subgroup survival analysis. Risk model was used independently as a prognostic indicator for the glioma patients. Notably, the low-risk patients displayed a substantial decrease in the immune checkpoints, the proportion of immune cells, ESTIMATE and immune score. IC50 values from the different risk groups allowed us to discern three drugs for the treatment of glioma patients. Lastly, the potential clinical significance of six DRLs was determined. CONCLUSIONS: A novel six DRLs signature was developed to predict prognosis and may provide valuable insights for patients with glioma seeking novel immunotherapy and targeted therapy.

6.
Sensors (Basel) ; 23(23)2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38067814

RESUMO

Due to the difficulty in dealing with non-stationary and nonlinear vibration signals using the single decomposition method, it is difficult to extract weak fault features from complex noise; therefore, this paper proposes a fault feature extraction method for rolling bearings based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and variational mode decomposition (VMD) methods. CEEMDAN was used to decompose the signal, and the signal was then screened and reconstructed according to the component envelope kurtosis. Based on the kurtosis of the maximum envelope spectrum as the fitness function, the sparrow search algorithm (SSA) was used to perform adaptive parameter optimization for VMD, which decomposed the reconstructed signal into several IMF components. According to the kurtosis value of the envelope spectrum, the optimal component was selected for an envelope demodulation analysis to realize fault feature extraction for rolling bearings. Finally, by using open data sets and experimental data, the accuracy of envelope kurtosis and envelope spectrum kurtosis as a component selection index was verified, and the superiority of the proposed feature extraction method for rolling bearings was confirmed by comparing it with other methods.

7.
Sensors (Basel) ; 23(20)2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37896602

RESUMO

Due to their symmetrized dot pattern, rolling bearings are more susceptible to noise than time-frequency characteristics. Therefore, this article proposes a symmetrized dot pattern extraction method based on the Frobenius and nuclear hybrid norm penalized robust principal component analysis (FNHN-RPCA) as well as decomposition and reconstruction. This method focuses on denoising the vibration signal before calculating the symmetric dot pattern. Firstly, the FNHN-RPCA is used to remove the non-correlation between variables to realize the separation of feature information and interference noise. After, the residual interference noise, irrelevant information, and fault features in the separated signal are clearly located in different frequency bands. Then, the ensemble empirical mode decomposition is applied to decompose this information into different intrinsic mode function components, and the improved DPR/KLdiv criterion is used to select components containing fault features for reconstruction. In addition, the symmetrized dot pattern is used to visualize the reconstructed signal. Finally, method validation and comparative analysis are conducted on the CWRU datasets and experimental bench data, respectively. The results show that the improved criteria can accurately complete the screening task, and the proposed method can effectively reduce the impact of strong noise interference on SDPs.

8.
Breast Cancer Res Treat ; 192(3): 573-582, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35129717

RESUMO

PURPOSE: In order to achieve an optimized method of axillary staging after neoadjuvant chemotherapy (NAC) in breast cancer patients with pretreatment positive axillary lymph nodes, we evaluated the feasibility and accuracy of nanoparticle-assisted axillary staging (NAAS) which combines carbon nanoparticles with standard sentinel lymph node biopsy (SLNB) with radioisotope and blue dye. METHODS: Invasive breast cancer patients with pre-NAC positive axillary lymph nodes who converted to ycN0 and received surgeries from November 2020 to March 2021 were included. All patients underwent ipsilateral NAAS followed by axillary lymph node dissection. Detection rate (DR), false-negative rate (FNR), negative predictive value (NPV) and accuracy of axillary staging were calculated. RESULTS: Eighty of 136 (58.8%) breast cancer patients converted to ycN0 after NAC and received NAAS. The DR, NPV and accuracy was 95.0%, 93.3% and 97.4% for NAAS, respectively. And the FNR was 4.2% (2/48) for NAAS, which was lower than that of standard dual-tracer SLNB (SD-SLNB) (9.5%, 4/42). Pretreatment clinical T4 classification was a risk factor for detection failure in NAAS (p = 0.016). When patients with pretreatment inflammatory breast cancers were excluded from analysis, FNR dropped to 2.2% (1/45) for NAAS. CONCLUSION: NAAS revealed great performance in invasive breast cancer patients with pre-NAC positive axillary lymph nodes who converted to ycN0. The application of NAAS reached a better balance between more accurate axillary evaluation and less intervention. Trial registration Chictr.org.cn (ChiCTR2000039814). Registered Nov 11, 2020.


Assuntos
Neoplasias da Mama , Nanopartículas , Axila/patologia , Neoplasias da Mama/patologia , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/patologia , Terapia Neoadjuvante , Estadiamento de Neoplasias , Biópsia de Linfonodo Sentinela/métodos
9.
Inorg Chem ; 61(46): 18660-18669, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36367455

RESUMO

An easy approach is suggested to obtain excellent piezoelectric performances in potassium sodium niobate (KNN)-based ceramics simultaneously with low dielectric loss (tanδ), high Curie temperature (TC), and electromechanical coupling factor (kp). Herein, a KNN-based ceramics system with nonstoichiometric Nb5+ is designed. Excessive Nb5+ occupying the B-site significantly influences the microstructural features and electrical properties of KNN-based ceramics. Furthermore, the excessive Nb5+ improves the temperature stability of ceramics by providing the domain wall pegging effect and defect dipole. A high TC = 300 °C, large kp = 0.516, and d33 = 450 pC/N can be simultaneously obtained in the KNN-based ceramics with nonstoichiometric Nb5+. These results confirm that the comprehensive electrical properties of KNN-based ceramics can be tuned by optimizing the content of nonstoichiometric Nb5+.

10.
New Phytol ; 229(1): 351-369, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32810889

RESUMO

Cell and tissue polarization is fundamental for plant growth and morphogenesis. The polar, cellular localization of Arabidopsis PIN-FORMED (PIN) proteins is crucial for their function in directional auxin transport. The clustering of PIN polar cargoes within the plasma membrane has been proposed to be important for the maintenance of their polar distribution. However, the more detailed features of PIN clusters and the cellular requirements of cargo clustering remain unclear. Here, we characterized PIN clusters in detail by means of multiple advanced microscopy and quantification methods, such as 3D quantitative imaging or freeze-fracture replica labeling. The size and aggregation types of PIN clusters were determined by electron microscopy at the nanometer level at different polar domains and at different developmental stages, revealing a strong preference for clustering at the polar domains. Pharmacological and genetic studies revealed that PIN clusters depend on phosphoinositol pathways, cytoskeletal structures and specific cell-wall components as well as connections between the cell wall and the plasma membrane. This study identifies the role of different cellular processes and structures in polar cargo clustering and provides initial mechanistic insight into the maintenance of polarity in plants and other systems.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Polaridade Celular , Análise por Conglomerados , Ácidos Indolacéticos , Proteínas de Membrana Transportadoras
11.
J Surg Oncol ; 123(1): 89-95, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33047336

RESUMO

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) are predictive for the response to neoadjuvant chemotherapy (NAC) of breast cancer. However, little is known about the predictive value of TILs for axillary lymph node involvement after NAC. METHODS: We analyzed 282 breast cancer patients who were operated following NAC and curative surgery from 2008 to 2018. TILs were assessed in core needle biopsies before NAC, and the biopsies were divided into three groups: low (0%-10% immune cells in stromal tissue within the tumor), intermediate (11%-59%), and high (≥60%). The patients were followed for an average of 63 months (range, 2-116 months). We analyzed retrospectively the predictive value of TILs for the response to NAC, including pathological complete response (pCR) and axillary lymph node involvement (positive lymph node ratio (LNR; the ratio of the number of nodes involved to the total number of nodes dissected)). The prognostic values of TILs and LNR were assessed. RESULTS: A pCR was achieved in 27 of 188 patients (14.4%) in the low-TIL group, in 14 of 57 patients (24.6%) in the intermediate-TIL group, and in 13 of 37 (35.1%) in the high-TIL group (p = .007). Among patients who underwent axillary lymph node dissection after NAC, patients with high TILs had lower LNR (p = 0021) compared with the other groups. Kaplan-Meier analysis showed that overall survival (OS; p < .001) and disease-free survival (p < .001) were significantly longer for patients with low LNR (≤0.2). TILs were positively correlated with disease-free survival (p = .028), but TILs did not correlate with OS (p = .171). Moreover, by multivariable analysis, LNR independently affected disease-free survival (p < .001). CONCLUSIONS: TILs may be predictive for pCR rate, postoperative residual lymph node involvement, and disease-free survival of breast cancer patients. High TILs may suggest favorable outcomes.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfonodos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Terapia Neoadjuvante/mortalidade , Recidiva Local de Neoplasia/imunologia , Neoplasia Residual/imunologia , Neoplasias de Mama Triplo Negativas/imunologia , Adulto , Feminino , Seguimentos , Humanos , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/patologia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Neoplasia Residual/tratamento farmacológico , Neoplasia Residual/patologia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/patologia
12.
Epidemiol Infect ; 149: e4, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33397519

RESUMO

Hypertension represents one of the most common pre-existing conditions and comorbidities in Coronavirus disease 2019 (COVID-19) patients. To explore whether hypertension serves as a risk factor for disease severity, a multi-centre, retrospective study was conducted in COVID-19 patients. A total of 498 consecutively hospitalised patients with lab-confirmed COVID-19 in China were enrolled in this cohort. Using logistic regression, we assessed the association between hypertension and the likelihood of severe illness with adjustment for confounders. We observed that more than 16% of the enrolled patients exhibited pre-existing hypertension on admission. More severe COVID-19 cases occurred in individuals with hypertension than those without hypertension (21% vs. 10%, P = 0.007). Hypertension associated with the increased risk of severe illness, which was not modified by other demographic factors, such as age, sex, hospital geological location and blood pressure levels on admission. More attention and treatment should be offered to patients with underlying hypertension, who usually are older, have more comorbidities and more susceptible to cardiac complications.


Assuntos
COVID-19/complicações , Hipertensão/complicações , Adulto , Idoso , COVID-19/diagnóstico , China , Comorbidade , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco
13.
J Biol Chem ; 294(52): 19923-19933, 2019 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-31732559

RESUMO

Plant development is regulated by both synergistic and antagonistic interactions of different phytohormones, including a complex crosstalk between ethylene and auxin. For instance, auxin and ethylene synergistically control primary root elongation and root hair formation. However, a lack of chemical agents that specifically modulate ethylene or auxin production has precluded precise delineation of the contribution of each hormone to root development. Here, we performed a chemical genetic screen based on the recovery of root growth in ethylene-related Arabidopsis mutants with constitutive "short root" phenotypes (eto1-2 and ctr1-1). We found that ponalrestat exposure recovers root elongation in these mutants in an ethylene signal-independent manner. Genetic and pharmacological investigations revealed that ponalrestat inhibits the enzymatic activity of the flavin-containing monooxygenase YUCCA, which catalyzes the rate-limiting step of the indole-3-pyruvic acid branch of the auxin biosynthesis pathway. In summary, our findings have identified a YUCCA inhibitor that may be useful as a chemical tool to dissect the distinct steps in auxin biosynthesis and in the regulation of root development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Oxigenases/metabolismo , Ftalazinas/química , Arabidopsis/genética , Proteínas de Arabidopsis/antagonistas & inibidores , Proteínas de Arabidopsis/genética , Sítios de Ligação , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Etilenos/metabolismo , Indóis/química , Indóis/metabolismo , Simulação de Acoplamento Molecular , Mutagênese , Oxigenases/antagonistas & inibidores , Oxigenases/genética , Fenótipo , Ftalazinas/metabolismo , Ftalazinas/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Estrutura Terciária de Proteína , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
14.
Exp Cell Res ; 383(2): 111546, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31398352

RESUMO

Diffuse axonal injury (DAI) is the predominant effect of severe traumatic brain injury and significantly contributes to cognitive deficits. The mechanisms that underlie these cognitive deficits are often associated with complex molecular alterations. α7nAChR, one of the abundant and widespread nicotinic acetylcholine receptors (nAChRs) in the brain, plays important physiological functions in the central nervous system. However, the relationship between temporospatial alterations in the α7nAChR and DAI-related learning and memory dysfunction are not completely understood. Our study detected temporospatial alterations of α7nAChR in vulnerable areas (hippocampus, internal capsule, corpus callosum and brain stem) of DAI rats and evaluated the development and progression of learning and memory dysfunction via the Morris water maze (MWM). We determined that α7nAChR expression in vulnerable areas was mainly reduced at the recovery of DAI in rats. Moreover, the escape latency of the injured group increased significantly and the percentages of the distance travelled and time spent in the target quadrant were significantly decreased after DAI. Furthermore, α7nAChR expression in the vulnerable area was significantly positively correlated with MWM performance after DAI according to regression analysis. In addition, we determined that a selective α7nAChR agonist significantly improved learning and memory dysfunction. Rats in the α7nAChR agonist group showed better learning and memory performance than those in the antagonist group. These results demonstrate that microstructural injury-induced alterations of α7nAChR in the vulnerable area are significantly correlated with learning and memory dysfunctions after DAI and that augmentation of the α7nAChR level by its agonist contributes to the improvement of learning and memory function.


Assuntos
Aconitina/análogos & derivados , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Disfunção Cognitiva/psicologia , Lesão Axonal Difusa/psicologia , Aprendizagem/efeitos dos fármacos , Memória/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/fisiologia , Aconitina/farmacologia , Animais , Benzamidas/uso terapêutico , Compostos Bicíclicos com Pontes/uso terapêutico , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/patologia , Lesão Axonal Difusa/complicações , Lesão Axonal Difusa/tratamento farmacológico , Lesão Axonal Difusa/patologia , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores
15.
Exp Cell Res ; 375(2): 10-19, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30639060

RESUMO

BACKGROUND: Müller cell gliosis not only plays an important physiological role by maintaining retinal neuronal homeostasis but is also associated with multiple pathological events in the retina, including optic nerve crush (ONC) injury. Modulating Müller cell gliosis contributes to the creation of a permissive environment for neuronal survival. However, the underlying mechanism of Müller cell gliosis has remained elusive. OBJECTIVE: To investigate the underlying mechanism of Müller cell gliosis after ONC. METHODS: Rats with ONC injury were transfected with miRNA-21 (miR-21) agomir (overexpressing miR-21) or antagomir (inhibiting miR-21) via intravitreous injection. Immunofluorescence and western blotting were performed to confirm the effects of miR-21 on Müller cell gliosis. The retinal nerve fiber layer (RNFL) thickness was measured using optical coherence tomography and the positive scotopic threshold response (pSTR) was recorded using electroretinogram. RESULTS: In the acute phase (14 days) after ONC, compared with the crushed group, inhibiting miR-21 promoted Müller cell gliosis, exhibiting thicker processes and increased GFAP expression. In the chronic phase (35 days), inhibiting miR-21 ameliorated Müller cell gliosis, which exhibited thicker and denser processes and increased GFAP expression. Retinal ganglion cell (RGC) counts in retinas showed that the number of surviving RGCs increased significantly in the antagomir group. The thickness of the RNFL increased significantly, and pSTR showed significant preservation of the amplitudes in the antagomir group. CONCLUSIONS: Inhibition of miR-21 promotes RGC survival, RNFL thickness and the recovery of RGC function by modulating Müller cell gliosis after ONC.


Assuntos
Células Ependimogliais/metabolismo , Gliose/metabolismo , MicroRNAs/genética , Traumatismos do Nervo Óptico/metabolismo , Células Ganglionares da Retina/metabolismo , Animais , Gliose/etiologia , Gliose/genética , Masculino , MicroRNAs/metabolismo , Compressão Nervosa , Traumatismos do Nervo Óptico/complicações , Traumatismos do Nervo Óptico/genética , Ratos , Ratos Sprague-Dawley , Células Ganglionares da Retina/fisiologia
16.
Nature ; 516(7529): 90-3, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25409144

RESUMO

The prominent and evolutionarily ancient role of the plant hormone auxin is the regulation of cell expansion. Cell expansion requires ordered arrangement of the cytoskeleton but molecular mechanisms underlying its regulation by signalling molecules including auxin are unknown. Here we show in the model plant Arabidopsis thaliana that in elongating cells exogenous application of auxin or redistribution of endogenous auxin induces very rapid microtubule re-orientation from transverse to longitudinal, coherent with the inhibition of cell expansion. This fast auxin effect requires auxin binding protein 1 (ABP1) and involves a contribution of downstream signalling components such as ROP6 GTPase, ROP-interactive protein RIC1 and the microtubule-severing protein katanin. These components are required for rapid auxin- and ABP1-mediated re-orientation of microtubules to regulate cell elongation in roots and dark-grown hypocotyls as well as asymmetric growth during gravitropic responses.


Assuntos
Arabidopsis/citologia , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Microtúbulos/metabolismo , Proteínas de Plantas/metabolismo , Receptores de Superfície Celular/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Proliferação de Células , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hipocótilo/citologia , Hipocótilo/metabolismo , Proteínas de Plantas/genética , Raízes de Plantas/citologia , Raízes de Plantas/metabolismo , Receptores de Superfície Celular/genética , Transdução de Sinais
17.
Cell Mol Life Sci ; 75(22): 4207-4222, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29938386

RESUMO

Axonal outgrowth and guidance require numerous extracellular cues and intracellular mediators that transduce signals in the growth cone to regulate cytoskeletal dynamics. However, the way in which cytoskeletal effectors respond to these signals remains elusive. Here, we demonstrate that Porf-2, a neuron-expressed RhoGTPase-activating protein, plays an essential role in the inhibition of initial axon growth by restricting the expansion of the growth cone in a cell-autonomous manner. Furthermore, the EphB1 receptor is identified as an upstream controller that binds and regulates Porf-2 specifically upon extracellular ephrin-B stimulation. The activated EphB forward signal deactivates Rac1 through the GAP domain of Porf-2, which inhibits growth cone formation and brakes axon growth. Our results therefore provide a novel GAP that regulates axon growth and braking sequentially through Eph receptor-independent and Eph receptor-dependent pathways.


Assuntos
Axônios/fisiologia , Proteínas Ativadoras de GTPase/metabolismo , Receptor EphB1/metabolismo , Transdução de Sinais , Animais , Axônios/metabolismo , Axônios/ultraestrutura , Células Cultivadas , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/fisiologia , Hipocampo/crescimento & desenvolvimento , Camundongos , Camundongos Knockout , Morfogênese , Domínios Proteicos
19.
Mol Cell Neurosci ; 80: 18-31, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28163190

RESUMO

The Rho family of small GTPases was considered as molecular switches in regulating multiple cellular events, including cytoskeleton reorganization. The Rho GTPase-activating proteins (RhoGAPs) are one of the major families of Rho GTPase regulators. RhoGAPs were initially considered negative mediators of Rho signaling pathways via their GAP domain. Recent studies have demonstrated that RhoGAPs also regulate numerous aspects of neuronal development and are related to various neurodegenerative diseases in GAP-dependent and GAP-independent manners. Moreover, RhoGAPs are regulated through various mechanisms, such as phosphorylation. To date, approximately 70 RhoGAPs have been identified; however, only a small portion has been thoroughly investigated. Thus, the characterization of important RhoGAPs in the central nervous system is crucial to understand their spatiotemporal role during different stages of neuronal development. In this review, we summarize the current knowledge of RhoGAPs in the brain with an emphasis on their molecular function, regulation mechanism and disease implications in the central nervous system.


Assuntos
Doenças do Sistema Nervoso Central/metabolismo , Sistema Nervoso Central , Proteínas Ativadoras de GTPase/metabolismo , Neurônios/fisiologia , Transdução de Sinais/fisiologia , Proteínas rho de Ligação ao GTP/metabolismo , Animais , Sistema Nervoso Central/citologia , Sistema Nervoso Central/crescimento & desenvolvimento , Sistema Nervoso Central/metabolismo , Humanos
20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(1): 54-58, 2018 Jan.
Artigo em Zh | MEDLINE | ID: mdl-29737090

RESUMO

OBJECTIVE: To investigate the expression of mRNA of aspartyl/asparaginyl beta-hydroxylase (ASPH) gene in invasive breast cancer (IBC) and the relationship between methylation of gene promoter and clinicopathological parameters. METHODS: In 91 cases of breast cancer tissues and matched normal tissues (MNT),mRNA expression of the ASPH gene was detected by reverse transcription of real-time fluorescence quantification PCR and the methylation status of CpG island in the ASPH gene promoter region was detected by methylation specific PCR (MSP).And the relationship between the expression and the clinicopathological features of breast cancer was analyzed. RESULTS: The expression of ASPH gene mRNA in IBC was significantly higher than that in MNT ( P<0.001).The fold change of ASPH mRNA expression was related to whether E-cadherin was positive (r=0.195, P=0.041).The positive rate of methylation of ASPH gene promoter in breast cancer and MNT was 47.3% (43/91) and 89.0% (81/91). The methylation rate of gene promoter was correlated with E-cadherin and tumor size ( P<0.05). CONCLUSION: The mRNA expression and promoter methylation rate of ASPH gene may play a role in the development and progression of breast cancer.


Assuntos
Neoplasias da Mama/genética , Proteínas de Ligação ao Cálcio/genética , Metilação de DNA , Proteínas de Membrana/genética , Oxigenases de Função Mista/genética , Proteínas Musculares/genética , Regiões Promotoras Genéticas , Antígenos CD/metabolismo , Caderinas/metabolismo , Estudos de Casos e Controles , Ilhas de CpG , Regulação Neoplásica da Expressão Gênica , Humanos , RNA Mensageiro
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