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1.
Neurobiol Dis ; : 105218, 2020 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-33296726

RESUMO

Parkinson's disease (PD) is the second most common neurodegenerative disease. Pathologically, PD is characterized by the formation of Lewy bodies (LBs) in the brain, which mainly comprises phosphorylated and aggregated α-synuclein (α-syn). The aberrant aggregation of α-syn is believed to play a key role in the pathogenesis of PD. While α-syn expression can be reduced by antisense oligonucleotides (ASOs), the challenge to deliver ASOs safely and effectively into the neurons remains unresolved. Here, we developed a safe and highly effective ASO delivery method by using exosomes. We first identified the ASO sequence that selectively reduced α-syn expression: ASO4. Exosome-mediated delivery of ASO4 (exo-ASO4) showed high cellular uptake and low toxicity in primary neuronal cultures. Exo-ASO4 also significantly attenuated α-syn aggregation induced by pre-formed α-syn fibrils in vitro. Exo-ASO4 intracerebroventricular injection into the brains of α-syn A53T mice, a transgenic model of PD, significantly decreased the expression of α-syn and attenuated its aggregation. Furthermore, exo-ASO4 ameliorated the degeneration of dopaminergic neurons in these mice. Finally, the α-syn A53T mice showed significantly improved locomotor functions after exo-ASO4 injection. Overall, this study demonstrates that exosome-mediated ASO4 delivery may be an effective treatment option for PD.

2.
Front Hum Neurosci ; 14: 568399, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33304251

RESUMO

Hormonal changes across the menstrual cycle have been shown to influence reward-related motivation and impulsive behaviors. Here, with the aim of examining the neural mechanisms underlying cognitive control of impulsivity, we compared event-related monetary delay discounting task behavior and concurrent functional magnetic resonance imaging (fMRI) revealed brain activity as well as resting state (rs)-fMRI activity, between women in the mid-luteal phase (LP) and women in the late follicular phase (FP). The behavioral data were analyzed and related to neural activation data. In the delay discounting task, women in the late FP were more responsive to short-term rewards (i.e., showed a greater discount rate) than women in the mid-LP, while also showing greater activity in the dorsal striatum (DS). Discount rate (transformed k) correlated with functional connectivity between the DS and dorsal lateral prefrontal cortex (dlPFC), consistent with previous findings indicating that DS-dlPFC circuitry may regulate impulsivity. Our rs-fMRI data further showed that the right dlPFC was significantly more active in the mid-LP than in late FP, and this effect was sensitive to absolute and relative estradiol levels during the mid-LP. DS-dlPFC functional connectivity magnitude correlated negatively with psychometric impulsivity scores during the late FP, consistent with our behavioral data and further indicating that relative estradiol levels may play an important role in augmenting cognitive control. These findings provide new insight into the treatment of conditions characterized by hyper-impulsivity, such as obsessive compulsive disorder, Parkinson disease, and attention deficit hyperactivity disorder. In conclusion, our results suggest that cyclical gonadal hormones affect cognitive control of impulsive behavior in a periodic manner, possibility via DS-dlPFC circuitry.

3.
PLoS One ; 15(8): e0237032, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790683

RESUMO

The behavioral activation system (BAS) and the behavioral inhibition system (BIS) have been proposed to relate to stable traits that predict inter-individual differences in motivation. Prior reports point dopamine (DA) pathways, mainly including ventral tegmental area (VTA) and substantia nigra (SN), implicate in subserving reward-related functions associated with BAS and inhibitory functions related with BIS. However, as an important factor that affects DA releasing, it remains an open question whether the ovarian hormones may also be related to BIS/BAS. Here, to investigate effects of the estradiol (E2) and progesterone (PROG) on BIS/BAS and related DA pathways, we employed a BIS/BAS scale and the resting-state functional magnetic resonance imaging (fMRI) during the late follicular phase (FP) and the mid-luteal phase (LP). On the behavioral level, when women had high PROG levels, their E2 levels were found positively correlated with BIS scores, but those women whose PROG levels were low, their E2 levels were negative correlation with BIS scores. On the neural level, we demonstrated BAS was related with the VTA pathway, included brain reward regions of nucleus accumbens (NAc) and orbitofrontal cortex (OFC). Meanwhile, the BIS was correlated with the SN-dorsolateral prefrontal cortex (dlPFC) pathway. ROI-based resting-state functional connectivity (RSFC) analyses further revealed that, RSFC between the SN and dlPFC was modulated by ovarian hormones. With higher PROG levels, increased E2 levels among women were accompanied by stronger RSFC of the SN-dlPFC, but when PROG levels were low, E2 levels were negatively correlated with the SN-dlPFC RSFC. These findings revealed a combined enhancement effect of E2 and PROG on BIS, and the SN-dlPFC pathway was mainly involved in this process.


Assuntos
Encéfalo/fisiologia , Dopamina/fisiologia , Inibição Psicológica , Motivação/fisiologia , Ovário/fisiologia , Adulto , Afeto/fisiologia , Encéfalo/diagnóstico por imagem , Neurônios Dopaminérgicos/fisiologia , Estradiol/fisiologia , Feminino , Neuroimagem Funcional , Humanos , Imagem por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Progesterona/fisiologia , Psicofisiologia , Substância Negra/diagnóstico por imagem , Substância Negra/fisiologia , Área Tegmentar Ventral/diagnóstico por imagem , Área Tegmentar Ventral/fisiologia , Adulto Jovem
4.
J Dairy Res ; 87(2): 170-174, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32482199

RESUMO

In this research communication we describe the DGAT1 sequence and promoter region in dairy cows and buffalo and compare the activities of DGAT1 between the two species in order to increase knowledge of the cause of milk fat variation. pGL-3 basic vectors were used to construct the reporter gene. Based on the predicted promoter region, 4 truncated plasmid vectors were constructed in cow-DGAT1 and 3 plasmid vectors in buffalo-DGAT1. Each reporter plasmid was transfected into the bovine mammary epithelial cell (BMEC), 293T cell, and CHO cells to analyze the activity using Dual-Luciferase Reporter Assay System. The results show that the region between -93 to -556 bp was essential for cow promoter activity while -84 to -590 bp was essential for buffalo promoter activity revealing these regions contain core promoter. The buffalo has higher promoter activity than cow yet it was not statistically significant. Comparison of candidate mutation K232A between cow and buffalo population revealed the presence of both the allelic population in dairy cows (lysine and alanine) however, only K (lysine) allelic amino acid was found in buffalo population. The absence of the alanine allelic population from buffalo explains the higher fat content of buffalo milk.

5.
Biomed Chromatogr ; 34(10): e4927, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32562289

RESUMO

A sensitive and selective high-performance liquid chromatography-tandam mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantification of sildenafil and its metabolite N-desmethyl sildenafil in human plasma. Sildenafil-d8 was used as an internal standard. The analytes were extracted by precipitation extraction and chromatographed on a C18 column using mobile phase A of water (containing 0.1% formic acid) and mobile phase B of acetonitrile (containing 0.1% formic acid) with gradient elution. Quantification was done using multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of m/z 475.4 → m/z 283.3 for sildenafil, m/z 461.4 → m/z 283.2 for N-desmethyl sildenafil and m/z 483.3 → m/z 108.1 for IS in positive ionization mode. The calibration curve was established over the range of 2.00-1,000 ng/ml and the correlation coefficient was >0.99. The intra-day and inter-day relative standard deviations were <6.5% for sildenafil and 6.3% for N-desmethyl sildenafil respectively. Accuracy determinaed at four concentrations was 86.50-105.67% for sildenafil and 96.83-114.40% for N-desmethyl sildenafil. This method was successfully applied to a pharmacokinetic description of sildenafil and the effect of food intake on the pharmacokinetics of sildenafil was also demonstrated in healthy Chinese volunteers.

6.
Environ Entomol ; 49(3): 667-672, 2020 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-32333018

RESUMO

Polycyclic aromatic hydrocarbons (PAHs), as well-recognized toxic chemical, cause the public hazard in environments. Here, we demonstrated the black soldier fly larvae (BSFL) could tolerate the PAHs and reduce their content. Four typical PAHs (1.0, 10.0, and 100.0 mg/kg), naphthalene, fluorene, phenanthrene, and pyrene, were individually spiked into BSFL conversion systems. The parameters for larval growth, conversion process, and PAHs removal were determined in spiked group and no-spiked control. The results show that the larval development time (19.7-21.0 d) in the half of PAH groups was significantly longer by 2-4 d than those in the control, while the relative growth rates (1.88-1.99% per day) in the majority PAH groups were lower. The larval mortalities (0-2.83%), harvest yields (80.20-85.91 g), conversion rates (14.71-15.83%), and eclosion rates (60.27-82.67%) in almost all of PAH groups did not significantly different from those in the control. The four PAHs potentially delayed the development time of BSFL, slowed the larval growth, and lower waste reduction rates, but these influences were slight and might be caused by the inhibition of PAHs to microbial activity. The BSFL-mortalities, conversion rates, yields, and eclosion rates were not significantly affected by the PAHs. Furthermore, BSFL effectively removed 34.1-84.2% of PAHs from subtracts in 18-21 d. The removal of PAHs with low concentration could be easier than those with high concentration by BSFL. The present results provide an alternative strategy to treat the waste contaminated by PAHs and elucidate the effect of PAHs on insects in the environment.


Assuntos
Dípteros , Hidrocarbonetos Policíclicos Aromáticos , Simuliidae , Animais , Larva , Hidrocarbonetos Policíclicos Aromáticos/toxicidade
7.
Neurorehabil Neural Repair ; 34(4): 321-332, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32102610

RESUMO

Background. Reorganization in motor areas have been suggested after motor imagery training (MIT). However, motor imagery involves a large-scale brain network, in which many regions, andnot only the motor areas, potentially constitute the neural substrate for MIT. Objective. This study aimed to identify the targets for MIT in stroke rehabilitation from a voxel-based whole brain analysis of resting-state functional magnetic resonance imaging (fMRI). Methods. Thirty-four chronic stroke patients were recruited and randomly assigned to either an MIT group or a control group. The MIT group received a 4-week treatment of MIT plus conventional rehabilitation therapy (CRT), whereas the control group only received CRT. Before and after intervention, the Fugl-Meyer Assessment Upper Limb subscale (FM-UL) and resting-state fMRI were collected. The fractional amplitude of low-frequency fluctuations (fALFF) in the slow-5 band (0.01-0.027 Hz) was calculated across the whole brain to identify brain areas with distinct changes between 2 groups. These brain areas were then targeted as seeds to perform seed-based functional connectivity (FC) analysis. Results. In comparison with the control group, the MIT group exhibited more improvements in FM-UL and increased slow-5 fALFF in the ipsilesional inferior parietal lobule (IPL). The change of the slow-5 oscillations in the ipsilesional IPL was positively correlated with the improvement of FM-UL. The MIT group also showed distinct alternations in FCs of the ipsilesional IPL, which were correlated with the improvement of FM-UL. Conclusions. The rehabilitation efficiency of MIT was associated with increased slow-5 oscillations and altered FC in the ipsilesional IPL. Clinical Trial Registration. http://www.chictr.org.cn . Unique Identifier. ChiCTR-TRC-08003005.

8.
Eur J Radiol ; 124: 108822, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31951895

RESUMO

PURPOSE: To propose an automatic approach based on a convolutional neural network (CNN) to evaluate the quality of T2-weighted liver magnetic resonance (MR) images as nondiagnostic (ND) or diagnostic (D). MATERIALS AND METHODS: We included 150 T2-weighted liver MR imaging examinations in this retrospective study. Each slice of liver image was annotated with a label D or ND by two radiologists with seven and six years of experience, respectively. Additionally, the radiologists segmented the liver region manually as the ground truth for liver segmentation. A CNN was trained to segment the liver region and another CNN was used to classify the qualities of patches extracted from the liver region. The quality of an image was obtained from the percentage of nondiagnostic patches in all liver patches in the image. Treating nondiagnostic as positive, the accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristic curve (AUC), and confusion matrix were used to evaluate our model. A Mann-Whitney U test was performed with the statistical significance set at 0.05. RESULTS: Our model achieved good performance with an accuracy of 88.3 %, sensitivity of 86.0 %, specificity of 89.4 %, PPV of 78.6 %, NPV of 93.4 %, and AUC of 0.911 (95 % confidence interval: 0.882-0.939, p < 0.05). The confusion matrix of our model indicated good concordance with that of the radiologists. CONCLUSIONS: The proposed two-step patch-based model achieved excellent performance when assessing the quality of liver MR images.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Hepatopatias/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Redes Neurais de Computação , Humanos , Fígado/diagnóstico por imagem , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
9.
IEEE Trans Neural Syst Rehabil Eng ; 27(10): 2237-2245, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31536007

RESUMO

A number of studies have suggested that motor imagery training (MIT) has a positive influence on the upper extremity motor recovery in stroke patients, but little is known about its neural basis. To investigate the cortical motor network plasticity after MIT, 34 chronic hemiplegic subjects with subcortical stroke were recruited and randomly allocated to either the conventional rehabilitation therapy (CRT) or the CRT + MIT. The patients were assessed with the upper limb section of Fugl-Meyer assessment Scale (FM-UL) and resting-state fMRI before and after the 4 weeks of treatment. Seed-based functional connectivity (FC) of the ipsilesional primary motor cortex (M1) and graph-theory based analysis were used to explore the relationships between the motor recovery and reorganization of motor networks. We found that the patients in the MIT group showed more improvement in the FM-UL scores compared with the CRT group. Both groups presented increased inter-hemispheric and decreased intra-hemispheric FC of the ipsilesional M1 after intervention. However, the MIT group showed increased FC of the ipsilesional M1 with the ipsilesional precentral and postcentral gyri, middle cingulate gyrus and supramarginal gyrus after intervention, while the CRT group showed decreased FC in these regions. In addition, the clustering coefficient was significantly increased in the MIT group but not in the CRT group, and the increment of clustering coefficient was significantly positively correlated with improvement of FM-UL scores. Therefore, MIT might contribute to the motor recovery in stroke patients through the following network reorganization, i.e., promoting the efficiency of regional neuronal communication and the reorganization of intrinsic FC of the ipsilesional M1 involving widely distributed motor network in both hemispheres.


Assuntos
Imaginação , Rede Nervosa/fisiopatologia , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Feminino , Lateralidade Funcional , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/diagnóstico por imagem , Córtex Motor/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Plasticidade Neuronal , Estudos Prospectivos , Recuperação de Função Fisiológica , Descanso , Acidente Vascular Cerebral/diagnóstico por imagem , Resultado do Tratamento
10.
Colloids Surf B Biointerfaces ; 183: 110452, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31473409

RESUMO

Currently used Gd-based and Mn-based small molecular MRI contrast agents fail to meet the requirements for the long-term monitoring, and the potential safety risk under high administration dose or repeat dosing needs to be considered. In the present study, a biocompatible macromolecular magnetic resonance imaging (MRI) contrast agents based on O-carboxymethyl chitosan (CMCS), CMCS-(Mn-DTPA)n was designed and synthesized. The relaxivity of CMCS-(Mn-DTPA)n is approximately 3.5 and 5.5 times higher than that of Gd-DTPA and Mn-DPDP in aqueous solution, respectively. The MRI signal intensity in the kidney and liver of Sprague Dawley (SD) rats is significantly increased at a dose of 0.03 mM Mn/kg b.w. CMCS-(Mn-DTPA)n accompanied by a long effective imaging window. According to in vitro studies, CMCS-(Mn-DTPA)n exhibits good cellular and blood biocompatibility at the dose necessary for MRI imaging. Based on the results from in vivo studies, manganese (Mn) is completely excreted from SD rats within ten days after administration and does not exert a pathological effect on the liver. CMCS-(Mn-DTPA)n represents a potentially novel MRI contrast agent due to its excellent relaxivity, long effective imaging window and good biocompatibility.


Assuntos
Quitosana/análogos & derivados , Meios de Contraste/química , Imagem por Ressonância Magnética/métodos , Manganês/química , Animais , Quelantes/química , Quitosana/química , Meios de Contraste/síntese química , Meios de Contraste/farmacocinética , Ácido Edético/análogos & derivados , Ácido Edético/química , Gadolínio DTPA/química , Rim/diagnóstico por imagem , Rim/metabolismo , Fígado/diagnóstico por imagem , Fígado/metabolismo , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/química , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
11.
Front Physiol ; 10: 902, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354533

RESUMO

Cognitive gains are reported to be induced by acute aerobic exercise, but the role of fitness in the effect of acute aerobic exercise on executive function remains unknown. Therefore, we aimed to examine the effect of fitness on acute exercise-induced changes in executive function from neural mechanism approach. Twenty-four female college students were assigned to high-fitness or low-fitness groups based on their cardiovascular fitness level, and then underwent functional magnetic resonance imaging while performing N-back tasks before and after 30 min of acute exercise. The behavioral results revealed significant interaction effects of group by time in the 0-back and 1-back tasks, but not in the 2-back task. The accuracy was significantly higher in the high-fitness group than in the low-fitness group before exercise in the 1-back and 2-back tasks. At the neural level, significant interaction effects of group by time were observed in all tasks. The 0-back and 1-back tasks activated the right cerebellum while the 2-back task activated subcortical regions. Our findings suggest that fitness moderates the effect of aerobic exercise on cognitive function, and provide the first neural evidence to support the influence of fitness on exercise-induced cognitive performance.

12.
Nanoscale Res Lett ; 13(1): 380, 2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30483904

RESUMO

Enhanced MRI (magnetic resonance imaging) plays a vital role in the early detection of tumor but with low specificity. Molecular imaging of angiogenesis could efficiently deliver contrast agents to the tumor site by specific targeted carriers. We designed and synthesized dual-targeted paramagnetic liposomes functionalized with two angiogenesis-targeting ligands, the αVß3 integrin-specific RGD (Arg-Gly-Asp) and the neuropilin-1 (NRP-1) receptor-specific ATWLPPR (Ala-Thr-Trp-Leu-Pro-Pro-Arg) (A7R). These liposomes were proved to be in the nanoparticle range and demonstrated to effectively encapsulate paramagnetic MRI contrast agents Gd-DTPA (gadolinium-diethylenetriamine pentaacetic acid). T1 relaxivity of various liposome formulations was lower than pure Gd-DTPA but with no statistically significant difference. In vitro cellular uptake and competitive inhibition assay showed the higher binding affinity of dual-targeted liposomes to HUVECs (human umbilical vein endothelial cells) and A549 cells compared with pure Gd-DTPA, non-targeted, and single-targeted liposomes, which was proved to be mediated by the binding of RGD/ανß3-integrin and A7R/NRP1. For MR imaging of mice bearing A549 cells in vivo, dual-targeted liposomes reached the highest SER (signal enhancement rate) value with a significant difference at all experimental time points. It was about threefold increase compared to pure Gd-DTPA and non-targeted liposomes and was 1.5-fold of single-targeted liposomes at 2 h post injection. The SER was lowered gradually and decreased only by 40% of the peak value in 6 h. Dual-targeted liposomes were likely to exert a synergistic effect and the specificity of delivering Gd-DTPA to the tumor site. Therefore, dual-ανß3-integrin-NRP1-targeting paramagnetic liposome with a RGD-ATWLPPR heterodimeric peptide might be a potent system for molecular imaging of tumor.

13.
Int J Mol Sci ; 19(11)2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30469332

RESUMO

Receptor-like cytoplasmic protein kinases (RLCKs) are involved in various activities in plant growth and development. We have totally identified 162, 160, and 402 RLCK genes in maize, rice, and Arabidopsis genomes, respectively. Phylogenetic analyses divided 724 RLCK genes into 15 subfamilies and similar structural patterns of kinase activity sites and functional sites were observed within the subfamilies. Furthermore, the structural patterns of intron/exon in the same subfamilies were similar, implicating their close evolutionary relationship. Chromosome distribution indicated that segmental duplication of RLCK genes might be a major mechanism contributing to the expansion of the RLCK superfamilies in maize, rice, and Arabidopsis, respectively. The analysis of the synteny relationship and gene structure indicated that the evolution of most RLCKs in maize were prior to rice and Arabidopsis. Most of the ratio of Ka/Ks is inferior to one, suggesting that RLCK genes have experienced the negative selection in maize, rice and Arabidopsis. Duplication time revealed that the maize was the earliest emergence among these three species. The expression profiles showed that there are some specifically expressed RLCK genes in maize root, leaf, ear, and tassel. These specific expression genes may participate in the developmental regulation of these maize tissues. Our results will be useful in providing new insights into evolution of RLCKs and revealing the regulatory network of maize, rice, and Arabidopsis development.


Assuntos
Evolução Molecular , Proteínas de Plantas/genética , Proteínas Quinases/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Duplicação Gênica , Íntrons , Oryza/enzimologia , Oryza/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Seleção Genética , Zea mays/enzimologia , Zea mays/genética
14.
Neuroimage Clin ; 20: 523-530, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30167372

RESUMO

Stroke has a large physical, psychological, and financial burden on patients, their families, and society. Based on functional networks (FNs) constructed from resting state fMRI data, network connectivity after stroke is commonly conjectured to be more randomly reconfigured. We find that this hypothesis depends on the severity of stroke. Head movement-corrected, resting-state fMRI data were acquired from 32 patients after stroke, and 37 healthy volunteers. We constructed anomaly FNs, which combine time series information of a patient with the healthy control group. We propose data-driven techniques to automatically identify regions of interest that are stroke relevant. Graph analysis based on anomaly FNs suggests consistently that strong connections in healthy controls are broken down specifically and characteristically for brain areas that are related to sensorimotor functions and frontoparietal control systems, but new links in stroke patients are rebuilt randomly from all possible areas. Entropic measures of complexity are proposed for characterizing the functional connectivity reorganization patterns, which are correlated with hand and wrist function assessments of stroke patients and show high potential for clinical use.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Imagem por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiologia , Acidente Vascular Cerebral/diagnóstico por imagem , Algoritmos , Humanos , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiologia , Distribuição Aleatória , Acidente Vascular Cerebral/fisiopatologia
15.
Int J Mol Sci ; 19(8)2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30072588

RESUMO

The number of lateral roots (LRs) of a plant determines the efficiency of water and nutrient uptake. Soybean is a typical taproot crop which is deficient in LRs. The number of LRs is therefore an important agronomic trait in soybean breeding. It is reported that the inflorescence deficient in abscission (IDA) protein plays an important role in the emergence of Arabidopsis LRs. Previously, the genes which encode IDA-like (IDL) proteins have been identified in the soybean genome. However, the functions of these genes in LR development are unknown. Therefore, it is of great value to investigate the function of IDL genes in soybean. In the present study, the functions of two root-specific expressed IDL genes, GmIDL2a and GmIDL4a, are investigated. The expressions of GmIDL2a and GmIDL4a, induced by auxin, are located in the overlaying tissue, where LRs are initiated. Overexpression of GmIDL2a and GmIDL4a increases the LR densities of the primary roots, but not in the elder root. Abnormal cell layer separation has also been observed in GmIDL2a- and GmIDL4a-overexpressing roots. These results suggest that the overlaying tissues of GmIDL2a- and GmIDL4a-overexpressing roots are looser and are suitable for the emergence of the LR primordium. Further investigation shows that the expression of some of the cell wall remodeling (CWR) genes, such as xyloglucan endotransglucosylase/hydrolases, expansins, and polygalacturonases, are increased when GmIDL2a and GmIDL4a are overexpressed in hairy roots. Here, we conclude that GmIDL2a and GmIDL4a function in LR emergence through regulating soybean CWR gene expression.


Assuntos
Parede Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Soja/crescimento & desenvolvimento , Sequência de Aminoácidos , Parede Celular/química , Parede Celular/genética , Ácidos Indolacéticos/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raízes de Plantas/química , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Alinhamento de Sequência , Soja/química , Soja/genética , Soja/metabolismo
16.
Hum Brain Mapp ; 39(11): 4373-4384, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29972261

RESUMO

Emerging evidence has suggested that abnormalities in regional spontaneous brain activity following stroke may be detected by intrinsic low-frequency oscillations (LFO) in resting-state functional MRI (R-fMRI). However, the relationship between hand function outcomes following stroke and local LFO synchronization in different frequency bands is poorly understood. In this study, we performed R-fMRI to examine the regional homogeneity (ReHo) at three different frequency bands (slow-5: .01-.027 Hz; slow-4: .027-.08 Hz; and typical band: .01-.1 Hz) in 26 stroke patients with completely paralyzed hands (CPH) and 26 matched patients with partially paralyzed hands (PPH). Compared to the PPH group, decreased ReHo in the bilateral cerebellum posterior lobes and the contralesional cerebellum anterior lobe was observed in the slow-5 band and the slow-4 band in the CPH group, respectively. The mean ReHo values in these regions were positively correlated with the Fugl-Meyer assessment (FMA) scores. In contrast, increased ReHo in the contralesional supplementary motor area and the contralesional superior temporal gyrus was observed in the slow-4 band and the slow-5 band, respectively. The mean ReHo values in these regions were negatively correlated with the FMA scores. Importantly, significant interactions were identified between the frequency bands and the subgroups of patients in the contralesional precentral gyrus and middle frontal gyrus. These findings indicate that frequency-dependent R-fMRI patterns may serve as potential biomarkers of the neural substrates associated with hand function outcomes following stroke.


Assuntos
Encéfalo/fisiopatologia , Mãos/fisiopatologia , Paresia/fisiopatologia , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Paresia/diagnóstico por imagem , Paresia/etiologia , Descanso , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia
17.
Hum Brain Mapp ; 39(8): 3388-3397, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29691945

RESUMO

Motor functions are supported through functional integration across the extended motor system network. Individuals following stroke often show deficits on motor performance requiring coordination of multiple brain networks; however, the assessment of connectivity patterns after stroke was still unclear. This study aimed to investigate the changes in intra- and inter-network functional connectivity (FC) of multiple networks following stroke and further correlate FC with motor performance. Thirty-three left subcortical chronic stroke patients and 34 healthy controls underwent resting-state functional magnetic resonance imaging. Eleven resting-state networks were identified via independent component analysis (ICA). Compared with healthy controls, the stroke group showed abnormal FC within the motor network (MN), visual network (VN), dorsal attention network (DAN), and executive control network (ECN). Additionally, the FC values of the ipsilesional inferior parietal lobule (IPL) within the ECN were negatively correlated with the Fugl-Meyer Assessment (FMA) scores (hand + wrist). With respect to inter-network interactions, the ipsilesional frontoparietal network (FPN) decreased FC with the MN and DAN; the contralesional FPN decreased FC with the ECN, but it increased FC with the default mode network (DMN); and the posterior DMN decreased FC with the VN. In sum, this study demonstrated the coexistence of intra- and inter-network alterations associated with motor-visual attention and high-order cognitive control function in chronic stroke, which might provide insights into brain network plasticity following stroke.


Assuntos
Encéfalo/fisiopatologia , Transtornos dos Movimentos/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/diagnóstico por imagem , Transtornos dos Movimentos/etiologia , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Descanso , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem
18.
J Magn Reson Imaging ; 48(4): 1112-1119, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29603826

RESUMO

BACKGROUND: The automatic segmentation of cerebral nuclei in the quantitative susceptibility mapping (QSM) images can provide assistance for surgical treatment and pathological mechanism studies. However, as the most frequently used segmentation method, the atlas method provides unsatisfactory results when segmenting the substantia nigra (SN) and the red nucleus (RN). PURPOSE: To propose and evaluate an improved automatic method based on seed points-discontinuity for segmentations of the SN and the RN in QSM images. STUDY TYPE: Prospective. SUBJECTS: In all, 22 subjects, 11 patients with Parkinson's disease (PD), and 11 healthy subjects (mean age of 68.0 ± 6.9 years) underwent MR scans. FIELD STRENGTH/SEQUENCE: 3T system and a 3D multiecho gradient echo sequence with monopolar readout gradient. ASSESSMENT: Manual segmentations by two radiologists (both with over 10 years of experience in neuroimaging) were used to establish a baseline for assessment. The Dice coefficient and the center-of-gravity distance was employed to evaluate the segmentation accuracy. STATISTICAL TESTS: The mean value and standard deviation of the Dice coefficient and center-of-gravity distance were calculated separately to compare segmentation results from the proposed method, the level set method, the atlas method (including the single-atlas method and the multi-atlas majority voting method). RESULTS: The statistical results of Dice coefficient of the SN and the RN between the ground truth and the segmentation were 0.79 ± 0.14 and 0.77 ± 0.06 for the proposed method, 0.40 ± 0.10 and 0.65 ± 0.09 for the level set method, 0.68 ± 0.09 and 0.64 ± 0.07 for the single-atlas method, 0.70 ± 0.06 and 0.68 ± 0.05 for the multi-atlas majority voting method, respectively. The proposed method also provides the lowest center-of-gravity distance value (1.05 ± 0.71 for the SN and 0.74 ± 0.35 for the RN). DATA CONCLUSION: The segmentation results of the proposed method performed well on the in vivo data and were closer to the manual segmentation than the atlas method. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:1112-1119.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imagem por Ressonância Magnética , Doença de Parkinson/diagnóstico por imagem , Núcleo Rubro/diagnóstico por imagem , Substância Negra/diagnóstico por imagem , Idoso , Algoritmos , Mapeamento Encefálico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Variações Dependentes do Observador , Estudos Prospectivos , Radiologia , Reprodutibilidade dos Testes
19.
Plant Biotechnol J ; 16(8): 1402-1414, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29327510

RESUMO

Pollen germination and pollen tube growth are important physiological processes of sexual reproduction of plants and also are involved in signal transduction. Our previous study reveals that ZmSTK1 and ZmSTK2 are two receptor-like cytoplasmic kinases (RLCK) homologs in Zea mays as members of receptor-like protein kinase (RLK) subfamily, sharing 86% identity at the amino acid level. Here, we report that ZmSTK1 and ZmSTK2, expressed at late stages of pollen development, regulate maize pollen development with additive effect. ZmSTK1 or ZmSTK2 mutation exhibited severe pollen transmission deficiency, which thus influenced pollen fertility. Moreover, the kinase domains of ZmSTKs were cross-interacted with C-terminus of enolases detected by co-immunoprecipitation (Co-IP) and yeast two-hybrid system (Y2H), respectively. Further, the detective ZmSTK1 or ZmSTK2 was associated with decreased activity of enolases and also reduced downstream metabolite contents, which enolases are involved in glycolytic pathway, such as phosphoenolpyruvate (PEP), pyruvate, ADP/ATP, starch, glucose, sucrose and fructose. This study reveals that ZmSTK1 and ZmSTK2 regulate maize pollen development and indirectly participate in glycolytic pathway.


Assuntos
Proteínas de Plantas/metabolismo , Pólen/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Zea mays/metabolismo , Proteínas de Plantas/genética , Pólen/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Zea mays/genética
20.
Front Hum Neurosci ; 11: 551, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29184490

RESUMO

Consistent attention and proper processing of infant faces by adults are essential for infant survival. Previous behavioral studies showed gender differences in processing infant cues (e.g., crying, laughing or facial attractiveness) and more importantly, the efforts invested in nurturing offspring. The underlying neural mechanisms of processing unknown infant faces provide hints for understanding behavioral differences. This functional magnetic resonance imaging (fMRI) study recruited 32 unmarried adult (16 females and 16 males) participants to view unfamiliar infant faces and rate the attractiveness. Adult faces were also included. Behaviorally, despite that females and males showed no differences in attractiveness ratings of infant faces, a positive correlation was found between female's (but not male's) subjective liking for infants and attractiveness ratings of the infant faces. Functionally, brain activations to infant faces were modulated by attractiveness differently in males and females. Specifically, in female participants, activities in the ventromedial prefrontal cortex (vmPFC) and striatum/Nucleus Accumbens (NAcc) were positively modulated by infant facial attractiveness, and the modulation coefficients of these two regions were positively correlated. In male participants, infant facial attractiveness negatively modulated the activity in the dorsomedial prefrontal cortex (dmPFC). Our findings reveal that different neural mechanisms are involved in the processing of infant faces, which might lead to observed behavioral differences between males and females towards the baby.

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