RESUMO
Gravity controls directional growth of plants, and the classical starch-statolith hypothesis proposed more than a century ago postulates that amyloplast sedimentation in specialized cells initiates gravity sensing, but the molecular mechanism remains uncharacterized. The LAZY proteins are known as key regulators of gravitropism, and lazy mutants show striking gravitropic defects. Here, we report that gravistimulation by reorientation triggers mitogen-activated protein kinase (MAPK) signaling-mediated phosphorylation of Arabidopsis LAZY proteins basally polarized in root columella cells. Phosphorylation of LAZY increases its interaction with several translocons at the outer envelope membrane of chloroplasts (TOC) proteins on the surface of amyloplasts, facilitating enrichment of LAZY proteins on amyloplasts. Amyloplast sedimentation subsequently guides LAZY to relocate to the new lower side of the plasma membrane in columella cells, where LAZY induces asymmetrical auxin distribution and root differential growth. Together, this study provides a molecular interpretation for the starch-statolith hypothesis: the organelle-movement-triggered molecular polarity formation.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Plastídeos , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Sensação Gravitacional , Raízes de Plantas/metabolismo , Plastídeos/metabolismo , Amido/metabolismo , Proteínas de Membrana/metabolismoRESUMO
Photomorphogenesis is a pivotal developmental strategy used by plants to respond to environmental light levels. During emergence from the soil and the establishment of photomorphogenesis, seedlings encounter increasing levels of UV-B irradiation and develop adaptive responses accordingly. However, the molecular mechanisms that orchestrate UV-B signaling cascades remain elusive. Here, we provide biochemical and genetic evidence that the prolonged signaling circuits of UV-B-induced photomorphogenesis involve two sets of E3 ligases and a transcription factor in Arabidopsis thaliana The UV-B-inducible protein RUP1/RUP2 associates with the CUL4-DDB1 scaffold to form an E3 ligase, which represses photomorphogenesis by mediating the degradation of HY5, the hub transcription factor in the light signaling pathway. Conversely, COP1 directly targets RUP1/RUP2 for ubiquitination and degradation, leading to balanced RUP1/RUP2 accumulation, alleviation of the COP1-HY5 interaction, and stabilization of HY5 protein. Therefore, our study reveals that these two E3-substrate modules, CUL4-DDB1-RUP1/RUP2-HY5 and COP1-RUP1/RUP2, constitute the repression and derepression machinery by which plants respond to prolonged UV-B irradiation in photomorphogenic development.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Arabidopsis/efeitos da radiação , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Culina/genética , Proteínas Culina/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Ligação Proteica , Ubiquitina-Proteína Ligases/genética , Raios UltravioletaRESUMO
Objective: To investigate the factors influencing accelerated aging in patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). Methods: A total of 216 patients diagnosed with T2DM and CHD between August 2019 and August 2023 at Xuzhou Central Hospital were selected. Patients were divided into an aging group and a non-aging group, based on the positive or negative values of phenotypic age acceleration (PhenoAgeAccel). Logistic regression analysis was conducted. Variables that had a univariate analysis P< 0.05 were included in the multivariate analysis to identify factors influencing aging in patients with T2DM and CHD, and the area under the curve of the model was reported. Results: This study included 216 patients, with 89 in the accelerated aging group, and 127 in the non-accelerated aging group. The average age of patients was 70.40 (95% CI: 69.10-71.69) years, with 137 males (63.4%). Compared with the non-accelerated aging group, patients in the accelerated aging group were older, with a higher proportion of males, and a higher prevalence of hypertension, stable angina pectoris, and unstable angina pectoris. Multivariate Logistic regression analysis indicated that the absolute value of neutrophils (NEUT#), urea (UREA), adenosine deaminase (ADA), and the triglyceride-glucose index (TyG) were risk factors for accelerated aging, while cholinesterase (CHE) was a protective factor. For each unit increase in NEUT#, UREA, ADA, and TyG, the risk of aging increased by 64%, 48%, 10%, and 789%, respectively. The overall area under the receiver operating characteristic (ROC) curve of the model in the training set was 0.894, with a 95% confidence interval (CI) of 0.851-0.938. Conclusion: NEUT#, CHE, UREA, ADA, and TyG are predictors of accelerated aging in patients with T2DM and CHD, with the model showing favorable overall predictive performance.
Assuntos
Doença das Coronárias , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/complicações , Masculino , Feminino , Idoso , Doença das Coronárias/epidemiologia , Doença das Coronárias/sangue , Pessoa de Meia-Idade , Senilidade Prematura/epidemiologia , Fatores de Risco , Envelhecimento , Triglicerídeos/sangue , China/epidemiologia , Adenosina Desaminase/metabolismo , Ureia/sangueRESUMO
BACKGROUND: Gastric cancer (GC) is prevalent and aggressive, especially when patients have distant lung metastases, which often places patients into advanced stages. By identifying prognostic variables for lung metastasis in GC patients, it may be possible to construct a good prediction model for both overall survival (OS) and the cumulative incidence prediction (CIP) plot of the tumour. AIM: To investigate the predictors of GC with lung metastasis (GCLM) to produce nomograms for OS and generate CIP by using cancer-specific survival (CSS) data. METHODS: Data from January 2000 to December 2020 involving 1652 patients with GCLM were obtained from the Surveillance, epidemiology, and end results program database. The major observational endpoint was OS; hence, patients were separated into training and validation groups. Correlation analysis determined various connections. Univariate and multivariate Cox analyses validated the independent predictive factors. Nomogram distinction and calibration were performed with the time-dependent area under the curve (AUC) and calibration curves. To evaluate the accuracy and clinical usefulness of the nomograms, decision curve analysis (DCA) was performed. The clinical utility of the novel prognostic model was compared to that of the 7th edition of the American Joint Committee on Cancer (AJCC) staging system by utilizing Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI). Finally, the OS prognostic model and Cox-AJCC risk stratification model modified for the AJCC system were compared. RESULTS: For the purpose of creating the OS nomogram, a CIP plot based on CSS was generated. Cox multivariate regression analysis identified eleven significant prognostic factors (P < 0.05) related to liver metastasis, bone metastasis, primary site, surgery, regional surgery, treatment sequence, chemotherapy, radiotherapy, positive lymph node count, N staging, and time from diagnosis to treatment. It was clear from the DCA (net benefit > 0), time-dependent ROC curve (training/validation set AUC > 0.7), and calibration curve (reliability slope closer to 45 degrees) results that the OS nomogram demonstrated a high level of predictive efficiency. The OS prediction model (New Model AUC = 0.83) also performed much better than the old Cox-AJCC model (AUC difference between the new model and the old model greater than 0) in terms of risk stratification (P < 0.0001) and verification using the IDI and NRI. CONCLUSION: The OS nomogram for GCLM successfully predicts 1- and 3-year OS. Moreover, this approach can help to appropriately classify patients into high-risk and low-risk groups, thereby guiding treatment.
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Liquid phase exfoliation (LPE) has emerged as a promising method for the industrial-scale production of graphene. However, one of its critical steps, namely sonication, has faced challenges due to high power consumption and low efficiency, leading to limited applicability in industrial settings. This study introduces a novel, cost-effective microfluidic sonication device designed to significantly reduce power consumption while efficiently assisting the LPE process for graphene production. By coupling a capillary with a buzzer and applying an appropriate electric signal, simulation and particle tracing experiments reveal the generation of robust shear forces resulting from acoustic streaming and cavitation when the capillary end is immersed in the liquid. For the first time, the capillary-based sonication device was effectively utilized for graphene exfoliation in a DMF (N,N-Dimethylformamide) + NaOH liquid phase system. The SEM (Scanning Electron Microscope) and Raman characterization results corroborate the successful exfoliation of 100 nm with thicknesses below 10 nm graphene sheets from graphite flakes using this pioneering device. The values of I2D/IG increase after processing, which suggests the exfoliation of graphite flakes into thinner graphene sheets. The vibration-based acoustofluidic effector represents a versatile and scalable miniature device, capable of being employed individually for small-batch production, thereby optimizing the utilization of raw 2D materials, particularly in experimental scenarios. Alternatively, it holds the potential for large-scale manufacturing through extensive parallelization, offering distinct advantages in terms of cost-efficiency and minimal power consumption.
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Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is a treatable autoimmune disorder affecting the central nervous system. Despite extensive research, the exact etiology and pathogenesis of this condition remain unclear. In recent years, autoimmune encephalitis (AE) after viral encephalitis (VE) has gathered significant attention. Here, we present a case report of autoimmune GFAP astrocytopathy after VE in a 43-year-old Asian male with a history of oral and labial herpes. The patient presented with high-grade fever, headache, urinary retention, unresponsiveness, and apathy. Elevated levels of protein and GFAP-IgG were observed in the cerebrospinal fluid (CSF), and enhanced brain magnetic resonance imaging (MRI) revealed linear enhancement oriented radially to the ventricles. Treatment with intravenous immunoglobulin (IVIG) resulted in symptom relief, reduced lesion enhancement, and decreased protein levels. This case report highlights bimodal encephalitis with no discernible interval between VE and autoimmune GFAP astrocytopathy, which poses diagnostic challenges. Notably, autoimmune GFAP astrocytopathy is a novel form of autoimmune encephalitis, and its treatment lacks sufficient clinical experience. Intriguingly, our patient demonstrated sensitivity to IVIG, a treatment that differed from past reports. Therefore, further exploration of treatment strategies for this condition is warranted.
Assuntos
Doenças Autoimunes do Sistema Nervoso , Encefalite Viral , Encefalite , Humanos , Masculino , Adulto , Imunoglobulinas Intravenosas/uso terapêutico , Proteína Glial Fibrilar Ácida , Encefalite/diagnóstico , Encefalite/tratamento farmacológico , Encefalite/etiologia , Encefalite Viral/tratamento farmacológicoRESUMO
Acute ischemic stroke (AIS) is known to trigger a cascade of inflammatory events that induces secondary tissue damages. As a type of regulated inflammatory cell death, necroptosis is associated with AIS, whilst its regulation during neuroinflammation is not well understood. In particular, the actual function of NOD-like-receptor family pyrin domain-containing-3(NLRP3) inflammasome in cortical neuronal necroptosis still not clear. Herein, we explored the function of nuclear factor erythroid-2 related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) in oxygen-glucose deprivation (OGD) induced neuronal necroptosis and its underlying mechanism. To establish an in vitro model of neuronal necrosis, we used OGD/caspase-8 inhibitors (Q-VD-OPh, QVD) to treat rat primary cortical neurons (PCNs) after reoxygenation, wherein we found that the model cause an elevated ROS levels by mediating TXNIP/NLRP3 interactions, which in turn activated the NLRP3 inflammasome. Also, we observed that regulation of nuclear factor erythroid-2 related factor-2 (Nrf2) promoted heme oxygenase-1 (HO-1) expression and decreased TXNIP (a protein that relate oxidative stress to activation of inflammasome) and ROS levels, which negatively regulated the expression of OGD-induced activation of NLRP3 inflammasomes. In addition, HO-1 weakened NLRP3 inflammation body activation, which suggests that Nrf2-regulated HO-1 could block the interaction between TXNIP and NLRP3 in OGD/R-treated cortical neurons by inhibiting ROS production. Our study has discovered the importance of Nrf2/HO-1 signaling cascade for inhibiting inflammasome of NLRP3, which negatively regulated necrosis. Therefore, NLRP3 is considered a potential target for a novel neuroprotective approach, which can expand the therapeutic windows of stroke drugs.
Assuntos
Inflamassomos , AVC Isquêmico , Ratos , Animais , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , AVC Isquêmico/metabolismo , Heme Oxigenase-1/metabolismo , Glucose/metabolismo , Necroptose , Necrose/metabolismo , Neurônios/metabolismo , Proteínas de Ciclo Celular/metabolismoRESUMO
Mn2+ ions doped ZnS semiconductor nanocrystals (ZnS:Mn NCs) were synthesized using colloidal chemical method at 70 degrees C without any capping agents. The as-prepared undoped ZnS and ZnS:Mn NCs were characterized by UV-Vis absorption spectra, fluorescent emission spectra, X-ray powder diffraction (XRD), inductively coupled plasma analysis (ICP), X-ray photoelectron spectroscopy (XPS), Dynamic light scattering (DLS), cyclic voltammogram and electronic transmission microscopy (TEM). The dependence of photoluminescence of ZnS:Mn NCs on dopant concentration was studied. The results show that Mn2+ ions mainly stay at ZnS nanocystal surface, and Mn2+-surface defect state complex was formed, as a result of which, surface defect emission of ZnS nanocrystals was substituted with Mn2+-related PL emission. The strongest fluorescent emission intensity was obtain at 1.85 at% Mn2+ doped ZnS:Mn NCs. The Mn2+ doped ZnS:Mn NCs are of 5 nm in diameter. The emission peak at 575 nm is attributed to d-d (4T1 --> 6A1) transition of Mn2+ ions. The existence of Mn2+-related photoluminescence could be well correlated with cyclic voltammogram of Mn2+-doped NCs, where pair of oxidation and reduction peaks were clearly observed due to the doped Mn2+ ions. The adsorbed Mn2+ ions on ZnS NCs produced neither Mn2+ emission nor redox peaks. For heavily doped ZnS:Mn NCs (4.87 at%), redox peaks gap in cyclic voltammogram became larger and new oxidation peak appeared. Correspondingly, when the Mn2+ doping concentration reached 4.87 at%, the Mn2+-related emission totally disappears due to the Mn-Mn interactions. This work implys that electrochemical technique is possibly an useful tool to probe the local structure of doped Mn2+ ions.
RESUMO
Ultraviolet-B (UV-B) light is an intrinsic part of sunlight that reaches the earth's surface, and affects plant survival and adaptation. How plants respond to UV-B light is regulated by the wavelength, intensity and duration of UV-B radiation, and is also regulated by photosynthetically active radiation perceived by phytochrome and cryptochrome photoreceptors. Non-damaging UV-B light promotes plant photomorphogenesis and UV-B acclimation which enhances plant tolerance against UV-B stress. However, high-level UV-B radiation induces DNA damage, generates reactive oxygen species (ROS) and impairs photosynthesis. Plants have evolved efficient mechanisms to utilize informational UV-B signal, and protect themselves from UV-B stress. UV RESISTANCE LOCUS8 (UVR8) is a conserved plant-specific UV-B photoreceptor. It interacts with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) to initiate UV-B-specific light signaling and regulate UV-B responsive gene expression. A set of transcription factors such as ELONGATED HYPOCOTYL5 (HY5) function downstream of the UVR8-COP1 module to promote seedling de-etiolation for photomorphogenic development and biosynthesis of sunscreen flavonoids for UV-B stress tolerance. In addition to UVR8 signaling pathways, plants subjected to damaging UV-B radiation initiate stress protection and repair mechanisms through UVR8-independent pathways. In this review, we summarize the emerging mechanisms underlying UV-B stress acclimation and protection in plants, primarily revealed in the model plant Arabidopsis thaliana.
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Gravity is a critical environmental factor regulating directional growth and morphogenesis in plants, and gravitropism is the process by which plants perceive and respond to the gravity vector. The cytoskeleton is proposed to play important roles in gravitropism, but the underlying mechanisms are obscure. Here we use genetic screening in Physcomitrella patens, to identify a locus GTRC, that when mutated, reverses the direction of protonemal gravitropism. GTRC encodes a processive minus-end-directed KCHb kinesin, and its N-terminal, C-terminal and motor domains are all essential for transducing the gravity signal. Chimeric analysis between GTRC/KCHb and KCHa reveal a unique role for the N-terminus of GTRC in gravitropism. Further study shows that gravity-triggered normal asymmetric distribution of actin filaments in the tip of protonema is dependent on GTRC. Thus, our work identifies a microtubule-based cellular motor that determines the direction of plant gravitropism via mediating the asymmetric distribution of actin filaments.
Assuntos
Bryopsida/fisiologia , Gravitropismo/fisiologia , Cinesinas/fisiologia , Proteínas de Plantas/fisiologia , Citoesqueleto de Actina/química , Citoesqueleto de Actina/fisiologia , Sequência de Bases , Bryopsida/genética , Mapeamento Cromossômico , Citoesqueleto/química , Citoesqueleto/fisiologia , DNA de Plantas/genética , Genes de Plantas , Gravitropismo/genética , Cinesinas/química , Cinesinas/genética , Microtúbulos/química , Microtúbulos/fisiologia , Mutagênese , Mutação , Proteínas de Plantas/química , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Domínios ProteicosRESUMO
Electrical spin-orbit torque (SOT) in magnetic insulators (MI) has been intensively studied due to its advantages in spin-orbitronic devices with ultralow energy consumption. However, the magnon torque in the MIs, which has the potential to further lower the energy consumption, still remains elusive. In this work, we demonstrate the efficient magnon torque transferred into an MI through an antiferromagnetic insulator. By fabricating a Pt/NiO/Tm3Fe5O12 heterostructure with different NiO thicknesses, we have systematically investigated the evolution of the transferred magnon torque. We show that the magnon torque efficiency transferred through the NiO into the MI can retain a high value (â¼50%), which is comparable to the previous report for the magnon torque transferred into the metallic magnet. Our study manifests the feasibility of realizing the pure magnon-based spin-orbitronic devices with ultralow energy consumption and high efficiency.
RESUMO
Non-damaging ultraviolet B (UV-B) light promotes photomorphogenic development and stress acclimation through UV-B-specific signal transduction in Arabidopsis. UV-B irradiation induces monomerization and nuclear translocation of the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8). However, it is not clear how the nuclear localization of UVR8 leads to changes in global gene expression. Here, we reveal that nuclear UVR8 governs UV-B-responsive transcriptional networks in concert with several previously known transcription factors, including ELONGATED HYPOCOTYL 5 (HY5) and PHYTOCHROME INTERACTING FACTOR 4 (PIF4). Based on the transcriptomic analysis, we identify MYB13 as a novel positive regulator in UV-B-induced cotyledon expansion and stress acclimation. MYB13 is UV-B inducible and is predominantly expressed in the cotyledons. Our results demonstrate that MYB13 protein functions as a transcription factor to regulate the expression of genes involved in auxin response and flavonoid biosynthesis through direct binding with their promoters. In addition, photoactivated UVR8 interacts with MYB13 in a UV-B-dependent manner and differentially modulates the affinity of MYB13 with its targets. Taken together, our results elucidate the cooperative function of the UV-B photoreceptor UVR8 with various transcription factors in the nucleus to orchestrate the expression of specific sets of downstream genes and, ultimately, mediate plant responses to UV-B light.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Proteínas Cromossômicas não Histona/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fatores de Transcrição/metabolismo , Transcrição Gênica , Raios Ultravioleta , Aclimatação/genética , Vias Biossintéticas/genética , Núcleo Celular/metabolismo , Núcleo Celular/efeitos da radiação , Cotilédone/crescimento & desenvolvimento , Flavonoides/biossíntese , Ácidos Indolacéticos/metabolismo , Modelos Biológicos , Regiões Promotoras Genéticas , Ligação Proteica , Estresse Fisiológico/genética , Transcriptoma/genéticaRESUMO
As part of the biorefinery concept for spent coffee grounds (SCG), production of activated carbon (AC) was investigated from the degreased coffee grounds (DCG) left behind after oil extraction (primarily for biodiesel). The oils were extracted through conventional solvent extraction with GC/GC-MS confirming the oil was comparable to oils produced industrially. More significantly, analysis showed the DCG AC to have a four-fold increase in mesoporosity compared with the SCG AC with mesopore volumes of 0.6 and 0.15â cm3 g-1 , respectively. Adsorption trials showed a ten-fold increase in capacity for AuIII from 8.7 to 88.6â mg g-1 with subsequent experiments confirming that DCG AC displayed standard behavior for mesoporous materials of increasing adsorption capacity with decreasing pH. This raises the potential for valorization of SCG into a functional material for water remediation without the need for templating agents or expansion pretreatments with the added bonus of an additional material being produced simultaneously.