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1.
bioRxiv ; 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38746136

RESUMO

Epilepsy, a neurological disorder affecting millions worldwide, poses great challenges in precisely delineating the epileptogenic zone - the brain region generating seizures - for effective treatment. High-frequency oscillations (HFOs) are emerging as promising biomarkers; however, the clinical utility is hindered by the difficulties in distinguishing pathological HFOs from non- epileptiform activities at single electrode and single patient resolution and understanding their dynamic role in epileptic networks. Here, we introduce an HFO-sequencing approach to analyze spontaneous HFOs traversing cortical regions in 40 drug-resistant epilepsy patients. This data- driven method automatically detected over 8.9 million HFOs, pinpointing pathological HFO- networks, and unveiled intricate millisecond-scale spatiotemporal dynamics, stability, and functional connectivity of HFOs in prolonged intracranial EEG recordings. These HFO sequences demonstrated a significant improvement in localization of epileptic tissue, with an 818.47% increase in concordance with seizure-onset zone (mean error: 2.92 mm), compared to conventional benchmarks. They also accurately predicted seizure outcomes for 90% AUC based on pre-surgical information using generalized linear models. Importantly, this mapping remained reliable even with short recordings (mean standard deviation: 3.23 mm for 30-minute segments). Furthermore, HFO sequences exhibited distinct yet highly repetitive spatiotemporal patterns, characterized by pronounced synchrony and predominant inward information flow from periphery towards areas involved in propagation, suggesting a crucial role for excitation-inhibition balance in HFO initiation and progression. Together, these findings shed light on the intricate organization of epileptic network and highlight the potential of HFO-sequencing as a translational tool for improved diagnosis, surgical targeting, and ultimately, better outcomes for vulnerable patients with drug-resistant epilepsy. One Sentence Summary: Pathological fast brain oscillations travel like traffic along varied routes, outlining recurrently visited neural sites emerging as critical hotspots in epilepsy network.

2.
BMC Geriatr ; 24(1): 222, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38439017

RESUMO

BACKGROUND: This study aimed to investigate the association of high-sensitivity C-reactive protein (hs-CRP) with incident frailty as well as its effects on pre-frailty progression and regression among middle-aged and older adults. METHODS: Based on the frailty index (FI) calculated with 41 items, 6890 eligible participants without frailty at baseline from China Health and Retirement Longitudinal Study (CHARLS) were categorized into health, pre-frailty, and frailty groups. Logistic regression models were used to estimate the longitudinal association between baseline hs-CRP and incident frailty. Furthermore, a series of genetic approaches were conducted to confirm the causal relationship between CRP and frailty, including Linkage disequilibrium score regression (LDSC), pleiotropic analysis, and Mendelian randomization (MR). Finally, we evaluated the association of hs-CRP with pre-frailty progression and regression. RESULTS: The risk of developing frailty was 1.18 times (95% CI: 1.03-1.34) higher in participants with high levels of hs-CRP at baseline than low levels of hs-CRP participants during the 3-year follow-up. MR analysis suggested that genetically determined hs-CRP was potentially positively associated with the risk of frailty (OR: 1.06, 95% CI: 1.03-1.08). Among 5241 participants with pre-frailty at baseline, we found pre-frailty participants with high levels of hs-CRP exhibit increased odds of progression to frailty (OR: 1.39, 95% CI: 1.09-1.79) and decreased odds of regression to health (OR: 0.84, 95% CI: 0.72-0.98) when compared with participants with low levels of hs-CRP. CONCLUSIONS: Our results suggest that reducing systemic inflammation is significant for developing strategies for frailty prevention and pre-frailty reversion in the middle-aged and elderly population.


Assuntos
Proteína C-Reativa , Fragilidade , Idoso , Humanos , Pessoa de Meia-Idade , Estudos Longitudinais , Proteína C-Reativa/genética , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Fragilidade/genética , Estudos de Coortes , Inflamação
3.
Plant Cell ; 36(5): 2021-2040, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309956

RESUMO

Calcium-dependent protein kinases (CPKs) can decode and translate intracellular calcium signals to induce plant immunity. Mutation of the exocyst subunit gene EXO70B1 causes autoimmunity that depends on CPK5 and the Toll/interleukin-1 receptor (TIR) domain resistance protein TIR-NBS2 (TN2), where direct interaction with TN2 stabilizes CPK5 kinase activity. However, how the CPK5-TN2 interaction initiates downstream immune responses remains unclear. Here, we show that, besides CPK5 activity, the physical interaction between CPK5 and functional TN2 triggers immune activation in exo70B1 and may represent reciprocal regulation between CPK5 and the TIR domain functions of TN2 in Arabidopsis (Arabidopsis thaliana). Moreover, we detected differential phosphorylation of the calmodulin-binding transcription activator 3 (CAMTA3) in the cpk5 background. CPK5 directly phosphorylates CAMTA3 at S964, contributing to its destabilization. The gain-of-function CAMTA3A855V variant that resists CPK5-induced degradation rescues immunity activated through CPK5 overexpression or exo70B1 mutation. Thus, CPK5-mediated immunity is executed through CAMTA3 repressor degradation via phosphorylation-induced and/or calmodulin-regulated processes. Conversely, autoimmunity in camta3 also partially requires functional CPK5. While the TIR domain activity of TN2 remains to be tested, our study uncovers a TN2-CPK5-CAMTA3 signaling module for exo70B1-mediated autoimmunity, highlighting the direct embedding of a calcium-sensing decoder element within resistance signalosomes.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Mutação , Imunidade Vegetal , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autoimunidade/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Regulação da Expressão Gênica de Plantas , Mutação/genética , Fosforilação , Imunidade Vegetal/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
J Diabetes Investig ; 15(1): 78-86, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37803908

RESUMO

BACKGROUND: This study aimed to investigate the effect of systemic inflammation, assessed by high sensitivity C-reactive protein (hs-CRP) levels, on prediabetes progression and regression in middle-aged and older adults based on the China Health and Retirement Longitudinal Study (CHARLS). METHODS: Participants with prediabetes from CHARLS were followed up 4 years later with blood samples collected for measuring fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c). The level of hs-CRP was assessed at baseline and categorized into tertiles (low, middle, and high groups). Prediabetes at baseline and follow-up was defined primarily according to the American Diabetes Association (ADA) criteria. Logistic regression models were used to estimate the odds ratios (ORs) and confidence intervals (CIs). We also performed stratified analyses according to age, gender, BMI, the presence of hypertension, and the disease history of heart disease and dyslipidemia and sensitivity analyses excluding a subset of participants with incomplete data. RESULTS: Of the 2,874 prediabetes included at baseline, 834 participants remained as having prediabetes, 146 progressed to diabetes, and 1,894 regressed to normoglycemia based on ADA criteria with a 4 year follow-up. After multivariate logistics regression analysis, prediabetes with middle (0.67-1.62 mg/L) and high (>1.62 mg/L) hs-CRP levels had an increased incidence of progressing to diabetes compared with prediabetes with low hs-CRP levels (<0.67 mg/L; OR = 1.846, 95%CI: 1.129-3.018; and OR = 1.632, 95%CI: 0.985-2.703, respectively), and the incidence of regressing to normoglycemia decreased (OR = 0.793, 95%CI: 0.645-0.975; and OR = 0.769, 95%CI: 0.623-0.978, respectively). Stratified analyses and sensitivity analyses showed consistent results. CONCLUSIONS: Low levels of hs-CRP are associated with a high incidence of regression from prediabetes to normoglycemia and reduced odds of progression to diabetes.


Assuntos
Estado Pré-Diabético , Pessoa de Meia-Idade , Humanos , Idoso , Proteína C-Reativa/metabolismo , Glicemia/análise , Estudos Longitudinais , Estudos Prospectivos , Fatores de Risco
5.
Int J Womens Health ; 14: 107-118, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35140527

RESUMO

BACKGROUND: Chemerin has been suggested to be a risk factor for osteoporosis; however, its relationship with osteoporotic fracture is poorly understood. Herein, we intend to explore the association between serum chemerin and osteoporotic fracture. METHODS: A total of 111 elderly women patients diagnosed with osteoporotic fracture were selected as the observation group, and 40 healthy subjects were enrolled as controls. Dual-energy X-ray absorptiometry, enzyme-linked immunosorbent assay, electrochemiluminescence immunoassay, and biochemical analysis were separately performed to determine body bone mineral density (BMD), chemerin levels, bone turnover markers, and other parameters. Pearson's correlation analysis was conducted to examine a relationship between chemerin and laboratory parameters. Moreover, the levels of chemokine-like receptor 1 (CMKLR), C-C motif chemokine receptor-like 2 (CCRL2), collagen type I alpha (COLA1), and runt-related transcription factor-2 (RUNX2) were confirmed by quantitative polymerase chain reaction, and the effect of chemerin on osteogenic differentiation of hFOB1.19 cells was indicated by tartrate-resistant acid phosphatase and alkaline phosphatase double staining. RESULTS: A higher level of chemerin was generally detected in patients with osteoporotic fracture compared with those without (P<0.05). Compared with controls, lower BMD levels and higher ß-CTx and P1NP levels were detected in patients with osteoporotic fracture (all P<0.05). Interestingly, chemerin level was negatively correlated to BMD, but positively related to P1NP and ß-CTx. Risk of osteoporotic fracture was 2.75-fold higher in subjects with each standard deviation increment of chemerin. Compared with controls, there were no significant differences in CMKLR1 and CCRL2 mRNA after incubation with osteogenic differentiation medium (all P>0.05), whereas there was a remarkable decrease of COLA1 and RUNX2 after incubation with chemerin for nine days (all P<0.05). Furthermore, prolonged incubation with chemerin enhanced osteoclast differentiation and maturation, consequently contributing to an increased risk of fracture. CONCLUSION: Chemerin is a strong and independent risk factor for osteoporosis-related fracture among elderly Chinese women.

6.
Neuroimage Clin ; 33: 102903, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34864288

RESUMO

Non-invasive MEG/EEG source imaging provides valuable information about the epileptogenic brain areas which can be used to aid presurgical planning in focal epilepsy patients suffering from drug-resistant seizures. However, the source extent estimation for electrophysiological source imaging remains to be a challenge and is usually largely dependent on subjective choice. Our recently developed algorithm, fast spatiotemporal iteratively reweighted edge sparsity minimization (FAST-IRES) strategy, has been shown to objectively estimate extended sources from EEG recording, while it has not been applied to MEG recordings. In this work, through extensive numerical experiments and real data analysis in a group of focal drug-resistant epilepsy patients' interictal spikes, we demonstrated the ability of FAST-IRES algorithm to image the location and extent of underlying epilepsy sources from MEG measurements. Our results indicate the merits of FAST-IRES in imaging the location and extent of epilepsy sources for pre-surgical evaluation from MEG measurements.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsias Parciais , Epilepsia , Encéfalo/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/cirurgia , Eletroencefalografia/métodos , Epilepsias Parciais/diagnóstico por imagem , Epilepsias Parciais/cirurgia , Epilepsia/diagnóstico por imagem , Epilepsia/cirurgia , Humanos , Imageamento por Ressonância Magnética , Magnetoencefalografia/métodos
7.
Front Hum Neurosci ; 16: 1019279, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36606248

RESUMO

Introduction: Meditation has been shown to enhance a user's ability to control a sensorimotor rhythm (SMR)-based brain-computer interface (BCI). For example, prior work have demonstrated that long-term meditation practices and an 8-week mindfulness-based stress reduction (MBSR) training have positive behavioral and neurophysiological effects on SMR-based BCI. However, the effects of short-term meditation practice on SMR-based BCI control are still unknown. Methods: In this study, we investigated the immediate effects of a short, 20-minute meditation on SMR-based BCI control. Thirty-seven subjects performed several runs of one-dimensional cursor control tasks before and after two types of 20-minute interventions: a guided mindfulness meditation exercise and a recording of a narrator reading a journal article. Results: We found that there is no significant change in BCI performance and Electroencephalography (EEG) BCI control signal following either 20-minute intervention. Moreover, the change in BCI performance between the meditation group and the control group was found to be not significant. Discussion: The present results suggest that a longer period of meditation is needed to improve SMR-based BCI control.

8.
Front Plant Sci ; 12: 798230, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970294

RESUMO

Upon pathogen recognition, a transient rise in cytoplasmic calcium levels is one of the earliest events in plants and a prerequisite for defense initiation and signal propagation from a local site to systemic plant tissues. However, it is unclear if calcium signaling differs in the context of priming: Do plants exposed to a first pathogen stimulus and have consequently established systemic acquired resistance (SAR) display altered calcium responses to a second pathogen stimulus? Several calcium indicator systems including aequorin, YC3.6 or R-GECO1 have been used to document local calcium responses to the bacterial flg22 peptide but systemic calcium imaging within a single plant remains a technical challenge. Here, we report on an experimental approach to monitor flg22-induced calcium responses in systemic leaves of primed plants. The calcium-dependent protein kinase CPK5 is a key calcium sensor and regulator of the NADPH oxidase RBOHD and plays a role in the systemic calcium-ROS signal propagation. We therefore compared flg22-induced cytoplasmic calcium changes in Arabidopsis wild-type, cpk5 mutant and CPK5-overexpressing plants (exhibiting constitutive priming) by introgressing the calcium indicator R-GECO1-mTurquoise that allows internal normalization through mTurquoise fluorescence. Aequorin-based analyses were included for comparison. Based on the R-GECO1-mTurquoise data, CPK5-OE appears to reinforce an "oscillatory-like" Ca2+ signature in flg22-treated local tissues. However, no change was observed in the flg22-induced calcium response in the systemic tissues of plants that had been pre-challenged by a priming stimulus - neither in wild-type nor in cpk5 or CPK5-OE-lines. These data indicate that the mechanistic manifestation of a plant immune memory in distal plant parts required for enhanced pathogen resistance does not include changes in rapid calcium signaling upstream of CPK5 but rather relies on downstream defense responses.

10.
Plant Physiol ; 184(2): 1056-1071, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32769161

RESUMO

The Arabidopsis (Arabidopsis thaliana) calmodulin-binding transcription activator3 (CAMTA3) is a repressor of immunity-related genes but an activator of cold-induced or general stress-responsive genes in plants. Post-transcriptional or posttranslational mechanisms have been proposed to control CAMTA3 functions in different stress responses. Here, we show that treatment with the bacterial flg22 elicitor induces CAMTA3 phosphorylation, which is accompanied by its destabilization and nuclear export. Two flg22-responsive mitogen-activated protein kinases (MAPKs), MPK3 and MPK6, directly phosphorylate CAMTA3, with the phospho-sites contributing to CAMTA3 degradation and suppression of downstream target gene expression. However, the flg22-induced nuclear export and phospho-mobility shift can still be observed for the CAMTA3 phospho-null variant of the MAPK-modified sites, suggesting additional flg22-responsive kinases might be involved. Taken together, we propose that flg22-induced CAMTA3 depletion facilitates de-repression of downstream defense target genes, which involves phosphorylation, increased protein turnover, and nucleo-cytoplasmic trafficking.


Assuntos
Transporte Ativo do Núcleo Celular/genética , Transporte Ativo do Núcleo Celular/fisiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Calmodulina/metabolismo , Fosforilação/fisiologia , Fatores de Transcrição/metabolismo , Calmodulina/genética , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Fosforilação/genética , Fatores de Transcrição/genética
11.
Cell Rep ; 32(6): 108006, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32783934

RESUMO

In multiple cortical areas, including the motor cortex, neurons have similar firing rate statistics whether we observe or execute movements. These "congruent" neurons are hypothesized to support action understanding by participating in a neural circuit consistently activated in both observed and executed movements. We examined this hypothesis by analyzing neural population structure and dynamics between observed and executed movements. We find that observed and executed movements exhibit similar neural population covariation in a shared subspace capturing significant neural variance. Further, neural dynamics are more similar between observed and executed movements within the shared subspace than outside it. Finally, we find that this shared subspace has a heterogeneous composition of congruent and incongruent neurons. Together, these results argue that similar neural covariation and dynamics between observed and executed movements do not occur via activation of a subpopulation of congruent single neurons, but through consistent temporal activation of a heterogeneous neural population.


Assuntos
Córtex Motor/fisiologia , Neurônios/fisiologia , Animais , Macaca mulatta
12.
Front Neurosci ; 14: 584971, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33551719

RESUMO

Sensorimotor rhythm (SMR)-based brain-computer interfaces (BCIs) provide an alternative pathway for users to perform motor control using motor imagery. Despite the non-invasiveness, ease of use, and low cost, this kind of BCI has limitations due to long training times and BCI inefficiency-that is, the SMR BCI control paradigm may not work well on a subpopulation of users. Meditation is a mental training method to improve mindfulness and awareness and is reported to have positive effects on one's mental state. Here, we investigated the behavioral and electrophysiological differences between experienced meditators and meditation naïve subjects in one-dimensional (1D) and two-dimensional (2D) cursor control tasks. We found numerical evidence that meditators outperformed control subjects in both tasks (1D and 2D), and there were fewer BCI inefficient subjects in the meditator group. Finally, we also explored the neurophysiological difference between the two groups and showed that the meditators had a higher resting SMR predictor, more stable resting mu rhythm, and a larger control signal contrast than controls during the task.

13.
Diabetes Metab Syndr Obes ; 12: 827-839, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31239739

RESUMO

Purpose: Quercetin, the most widely distributed flavonoid, has been shown to have multiple properties and beneficial effects on various metabolic diseases. Thus, our aim was to investigate the underlying mechanism whereby quercetin regulates renal lipid accumulation and ameliorates early diabetic renal injuries in Leprdb/Leprdb (db/db) mice, a model of type 2 diabetes. Methods: db/db mice were administered either 50 mg/kg or 100 mg/kg quercetin by oral gavage once a day to evaluate its effects on early stage diabetic nephropathy; mice were sacrificed at the end of the 10th week after intervention; a similar number of db/db and db/m mice were used as controls. During the experimental study, the general status of the animals was observed daily; body weight and blood glucose concentrations were measured at bi-weekly intervals. Biochemical parameters of lipid metabolism were measured by automatic biochemical analyzer. Renal function parameters were performed using commercial kits. Early renal histological changes and lipid accumulation were demonstrated by H&E staining and Oil-Red-O staining, respectively. Moreover, the expression of key proteins in the low-density lipoprotein receptors (LDLr)-SREBP-2-SREBP cSCAP signaling pathway in the kidneys of diabetic mice was detected by Western blot assay. Results: Compared with diabetic controls, quercetin not only ameliorated albuminuria and urinary albumin-to-creatinine ratio, but also decreased blood urea nitrogen and glucose, serum cholesterol, triglycerides, and low-density lipoprotein cholesterol, whereas it had no remarkable effect on the high-density lipoprotein cholesterol in diabetic db/db mice. Additionally, the evidently down regulated expression of LDLr, HMGCR, SREBP-2, and SCAP subsequently attenuated the renal lipid profile change and lipid droplet accumulation, resulting in the alleviation of renal injury of db/db mice. Conclusion: Quercetin safely and efficiently alleviates early diabetic renal injuries, possibly through improving the lipid metabolism via SCAP-SREBP2-LDLr signaling pathway.

14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 874-877, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440530

RESUMO

Speckle noise corrupts medical ultrasound images and suppression of speckle noise is valuable for image interpretation. This paper presents a new method for speckle suppression named the maximum likelihood based weighted nuclear norm minimization (MLWNNM) filtering by integrating the maximum likelihood estimation (MLE) with the weighted nuclear norm minimization (WNNM). The MLE is first used to get an initially filtered image with reduced Rayleigh distributed noise, and then the WNNM is applied to further improve the denoising effect by preserving and enhancing tissue details. Simulation work shows that when the noise variance is as high as 0.14, the MLWNNM improves the Pratt's figure of merit, peak signal to noise ratio, and mean structural similarity by 123.51%, 0.84%, and 6.13%, respectively, in contrast to the best values of other six methods. Experimental results on clinical ultrasound images suggest that the MLWNNM outperforms other six methods in noise reduction and detail preservation.


Assuntos
Algoritmos , Aumento da Imagem , Funções Verossimilhança , Ultrassonografia , Artefatos , Razão Sinal-Ruído
15.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 981-986, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30440555

RESUMO

Mirror neurons, which fire during both the execution and observation of movement, are believed to play an important role in motor processing and learning. However, much work still remains to understand the similarities and differences in how these neurons compute in the motor cortex during movement execution and observation. Here, we performed experiments where a monkey both executes and observes a center-out-and-back task within the same experimental session. By recording from putatively the same neural population, we were able to analyze and compare single neuron statistics between movement execution and observation. We found that a majority of neurons in the primary motor cortex (M1) and dorsal premotor cortex (PMd) have statistically different firing rate statistics between movement execution and observation. As a result of this difference, we then wondered if neurons during movement observation exhibited a similar characteristic to those during movement execution: changing of preferred directions as a function of movement speed. Interestingly, we found that while observed movement speed is encoded in the neural population, it only alters a small proportion of the neuron's firing rate statistics. These results suggest that neural populations in Ml and PMd process information related to movement differently between execution and observation.


Assuntos
Neurônios-Espelho/fisiologia , Córtex Motor/fisiologia , Movimento/fisiologia , Animais , Macaca mulatta , Masculino , Córtex Motor/citologia , Desempenho Psicomotor/fisiologia
16.
Plant Cell ; 29(4): 726-745, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28280093

RESUMO

Crosstalk between posttranslational modifications, such as ubiquitination and phosphorylation, play key roles in controlling the duration and intensity of signaling events to ensure cellular homeostasis. However, the molecular mechanisms underlying the regulation of negative feedback loops remain poorly understood. Here, we uncover a pathway in Arabidopsis thaliana by which a negative feedback loop involving the E3 ubiquitin ligase PUB22 that dampens the immune response is triggered by MITOGEN-ACTIVATED PROTEIN KINASE3 (MPK3), best known for its function in the activation of signaling. PUB22's stability is controlled by MPK3-mediated phosphorylation of residues localized in and adjacent to the E2 docking domain. We show that phosphorylation is critical for stabilization by inhibiting PUB22 oligomerization and, thus, autoubiquitination. The activity switch allows PUB22 to dampen the immune response. This regulatory mechanism also suggests that autoubiquitination, which is inherent to most single unit E3s in vitro, can function as a self-regulatory mechanism in vivo.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Imunidade Vegetal/genética , Ligação Proteica , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Ubiquitina-Proteína Ligases/genética , Ubiquitinação/genética , Ubiquitinação/fisiologia
17.
Sci Rep ; 7: 40844, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-28102350

RESUMO

Seed size is a major determinant of seed yield but few is known about the genetics controlling of seed size in plants. Phytohormones cytokinin and brassinosteroid were known to be involved in the regulation of herbaceous plant seed development. Here we identified a homolog of Auxin Response Factor 19 (JcARF19) from a woody plant Jatropha curcas and genetically demonstrated its functions in controlling seed size and seed yield. Through Virus Induced Gene Silencing (VIGS), we found that JcARF19 was a positive upstream modulator in auxin signaling and may control plant organ size in J. curcas. Importantly, transgenic overexpression of JcARF19 significantly increased seed size and seed yield in plants Arabidopsis thaliana and J. curcas, indicating the importance of auxin pathway in seed yield controlling in dicot plants. Transcripts analysis indicated that ectopic expression of JcARF19 in J. curcas upregulated auxin responsive genes encoding essential regulators in cell differentiation and cytoskeletal dynamics of seed development. Our data suggested the potential of improving seed traits by precisely engineering auxin signaling in woody perennial plants.


Assuntos
Jatropha/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Citoesqueleto/metabolismo , Inativação Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Ácidos Indolacéticos/metabolismo , Jatropha/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Vírus de Plantas/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Ligação Proteica , Sementes/fisiologia , Alinhamento de Sequência , Transdução de Sinais , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética
18.
J Sep Sci ; 40(2): 567-573, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27860261

RESUMO

Capillary electrophoresis with fluorescence detection was utilized to probe the self-assembly between cyanine group dye labeled tetrahistidine containing peptide and CdSe/ZnS quantum dots, inside the capillary. Quantum dots and cyanine group dye labeled tetrahistidine containing peptide were injected into the capillary one after the other and allowed to self-assemble. Their self-assembly resulted into a measurable Förster resonance energy transfer signal between quantum dots and cyanine group dye labeled tetrahistidine containing peptide. The Förster resonance energy transfer signal increased upon increasing the cyanine group dye labeled tetrahistidine containing peptide/quantum dot molar ratio and reached a plateau at the 32/1 molar ratio. Additionally, the Förster resonance energy transfer signal was also affected by the increment of the interval time of injection and the sampling time. Online ligand exchange experiments were used to assess, the potential of a monovalent ligand of imidazole and a hexavalent ligand peptide, to displace surface bound cyanine group dye labeled peptide ligands from the quantum dots surface. Under optimal conditions, a linear relationship between the integrated peak areas and hexavalent ligand peptide was obtained at a hexavalent ligand concentration range of 0-0.5 mM. Therefore, the present assay has the potential to be applied in the online ligands detection.


Assuntos
Técnicas de Química Analítica/instrumentação , Eletroforese Capilar , Transferência Ressonante de Energia de Fluorescência , Peptídeos/metabolismo , Pontos Quânticos/metabolismo , Ligantes
19.
PLoS One ; 11(12): e0167434, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28002448

RESUMO

BACKGROUND: Resistance to intravenous immunoglobulin (IVIG) occurs in 10-20% of patients with Kawasaki disease (KD). The risk of resistance is about two-fold higher in patients with elevated gamma glutamyl transferase (GGT) levels. We sought to understand the biological mechanisms underlying IVIG resistance in patients with elevated GGT levels. METHOD: We explored the association between elevated GGT levels and IVIG-resistance with a cohort of 686 KD patients (Cohort I). Gene expression data from 130 children with acute KD (Cohort II) were analyzed using the R square statistic and false discovery analysis to identify genes that were differentially represented in patients with elevated GGT levels with regard to IVIG responsiveness. Two additional KD cohorts (Cohort III and IV) were used to test the hypothesis that sialylation and GGT may be involved in IVIG resistance through neutrophil apoptosis. RESULTS: Thirty-six genes were identified that significantly explained the variations of both GGT levels and IVIG responsiveness in KD patients. After Bonferroni correction, significant associations with IVIG resistance persisted for 12 out of 36 genes among patients with elevated GGT levels and none among patients with normal GGT levels. With the discovery of ST6GALNAC3, a sialyltransferase, as the most differentially expressed gene, we hypothesized that sialylation and GGT are involved in IVIG resistance through neutrophil apoptosis. We then confirmed that in Cohort III and IV there was significantly less reduction in neutrophil count in IVIG non-responders. CONCLUSIONS: Gene expression analyses combining molecular and clinical datasets support the hypotheses that: (1) neutrophil apoptosis induced by IVIG may be a mechanism of action of IVIG in KD; (2) changes in sialylation and GGT level in KD patients may contribute synergistically to IVIG resistance through blocking IVIG-induced neutrophil apoptosis. These findings have implications for understanding the mechanism of action in IVIG resistance, and possibly for development of novel therapeutics.


Assuntos
Resistência a Medicamentos , Imunoglobulinas Intravenosas/uso terapêutico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , gama-Glutamiltransferase/sangue , Doença Aguda , Alanina Transaminase/sangue , Apoptose , Proteína C-Reativa/análise , Pré-Escolar , Estudos de Coortes , Feminino , Expressão Gênica , Humanos , Lactente , Masculino , Síndrome de Linfonodos Mucocutâneos/sangue , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Neutrófilos/citologia , Razão de Chances , Espécies Reativas de Oxigênio/metabolismo , Fatores de Risco , Sialiltransferases/genética , Sialiltransferases/metabolismo
20.
J Sep Sci ; 39(23): 4653-4659, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27696714

RESUMO

Herein, we report an assay for detecting the binding of a multivalent peptide and antibody within a capillary with the use of fluorescence coupled capillary electrophoresis. Quantum dots and a c-Myc tag containing peptide EQKLISEEDLG4 H6 were injected sequentially and formed a multivalent quantum dot-EQKLISEEDLG4 H6 assembly within the capillary. The efficiency of the quantum dot-peptide self-assembly was affected by the peptide/quantum dot molar ratio, sampling time, and interval time. Finally, the binding of the monoclonal anti-c-Myc antibody and the multivalent quantum dot-EQKLISEEDLG4 H6 ligand was studied using an in-capillary assay. The microscopic dissociation constant for the self-assembly of monoclonal anti-c-Myc antibody and quantum dot-EQKLISEEDLG4 H6 was determined to be 14.1 µM with a stoichiometry of the peptide-antibody complex of 1.7 determined after fitting this to the Hill equation. This method can be further extended to detect a wide range of biomolecule-biomolecule binding interactions.


Assuntos
Anticorpos/química , Imunoconjugados/química , Peptídeos/química , Pontos Quânticos , Eletroforese Capilar , Ligantes
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