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1.
J Magn Reson Imaging ; 57(1): 227-235, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35652509

RESUMO

BACKGROUND: Differential diagnosis of brain metastases subtype and primary central nervous system lymphoma (PCNSL) is necessary for treatment decisions. The application of machine learning facilitates the classification of brain tumors, but prior investigations into primary lymphoma and brain metastases subtype classification have been limited. PURPOSE: To develop a machine-learning model to classify PCNSL, brain metastases with primary lung and non-lung origin. STUDY TYPE: Retrospective. POPULATION: A total of 211 subjects with pathologically confirmed PCNSL or brain metastases (training cohort 168 and testing cohort 43). FIELD STRENGTH/SEQUENCE: A 3.0 T axial contrast-enhanced T1-weighted spin-echo inversion recovery sequence (T1WI-CE), axial T2-weighted fluid-attenuation inversion recovery sequence (T2FLAIR) ASSESSMENT: Several machine-learning models (support vector machine, random forest, and K-nearest neighbors) were built with least absolute shrinkage and selection operator (LASSO) using features from T1WI-CE, T2FLAIR, and clinical. The model with the highest performance in the training cohort was selected to differentiate lesions in the testing cohort. Then, three radiologists conducted a two-round classification (with and without model reference) using images and clinical information from testing cohorts. STATISTICAL TESTS: Five-fold cross-validation was used for model evaluation and calibration. Model performance was assessed based on sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC). RESULTS: Twenty-five image features were selected by LASSO analysis. Random forest classifier was selected for its highest performance on the training set with an AUC of 0.73. After calibration, this model achieved an accuracy of 0.70 on the testing set. Accuracies of all three radiologists improved under model reference (0.49 vs. 0.70, 0.60 vs. 0.77, 0.58 vs. 0.72, respectively). DATA CONCLUSION: The random forest model based on conventional MRI and clinical data can diagnose PCNSL and brain metastases subtypes (lung and non-lung origin). Model classification can help foster the diagnostic accuracy of specialists and streamline prognostication workflow. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.


Assuntos
Neoplasias Encefálicas , Linfoma , Humanos , Estudos Retrospectivos , Neoplasias Encefálicas/patologia , Imageamento por Ressonância Magnética/métodos , Linfoma/diagnóstico por imagem , Linfoma/patologia , Sistema Nervoso Central/patologia
2.
Front Neurosci ; 16: 915164, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35860295

RESUMO

Radiation-induced functional and structural brain alterations are well documented in patients with nasopharyngeal carcinoma (NPC), followed by radiotherapy (RT); however, alterations in structure-function coupling remain largely unknown. Herein, we aimed to assess radiation-induced structure-function decoupling and its importance in predicting radiation encephalopathy (RE). We included 62 patients with NPC (22 patients in the pre-RT cohort, 18 patients in the post-RT-RE+ve cohort, and 22 patients in the post-RT-RE-ve cohort). A metric of regional homogeneity (ReHo)/voxel-based morphometry (VBM) was used to detect radiation-induced structure-function decoupling, which was then used as a feature to construct a predictive model for RE. Compared with the pre-RT group, patients in the post-RT group (which included post-RT-RE+ve and post-RT-RE-ve) showed higher ReHo/VBM coupling values in the substantia nigra (SN), the putamen, and the bilateral thalamus and lower values in the brain stem, the cerebellum, the bilateral medial temporal lobes (MTLs), the bilateral insula, the right precentral and postcentral gyri, the medial prefrontal cortex (MPFC), and the left inferior parietal lobule (IPL). In the post-RT group, negative correlations were observed between maximum dosage of RT (MDRT) to the ipsilateral temporal lobe and ReHo/VBM values in the ipsilateral middle temporal gyrus (MTG). Moreover, structure-function decoupling in the bilateral superior temporal gyrus (STG), the bilateral precentral and postcentral gyri, the paracentral lobules, the right precuneus and IPL, and the right MPFC exhibited excellent predictive performance (accuracy = 88.0%) in identifying patients likely to develop RE. These findings show that ReHo/VBM may be a novel effective imaging metric that reflects the neural mechanism underlying RE in patients with NPC.

3.
Cerebellum ; 21(3): 358-367, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34264505

RESUMO

Spinocerebellar ataxias (SCAs) are a large group of hereditary neurodegenerative diseases characterized by ataxia and dysarthria. Due to high clinical and genetic heterogeneity, many SCA families are undiagnosed. Herein, using linkage analysis, WES, and RP-PCR, we identified the largest SCA36 pedigree in Asia. This pedigree showed some distinct clinical characteristics. Cognitive impairment and gaze palsy are common and severe in SCA36 patients, especially long-course patients. Although no patients complained of hearing loss, most of them presented with hearing impairment in objective auxiliary examination. Voxel-based morphometry (VBM) demonstrated a reduction of volumes in cerebellum, brainstem, and thalamus (corrected P < 0.05). Reduced volumes in cerebellum were also found in presymptomatic carriers. Resting-state functional MRI (R-fMRI) found reduced ReHo values in left cerebellar posterior lobule (corrected P < 0.05). Diffusion tensor imaging (DTI) demonstrated a reduction of FA values in cerebellum, midbrain, superior and inferior cerebellar peduncle (corrected P < 0.05). MRS found reduced NAA/Cr values in cerebellar vermis and hemisphere (corrected P < 0.05). Our findings could provide new insights into management of SCA36 patients. Detailed auxiliary examination are recommended to assess hearing or peripheral nerve impairment, and we should pay more attention to eye movement and cognitive changes in patients. Furthermore, for the first time, our multimodel neuroimaging evaluation generate a full perspective of brain function and structure in SCA36 patients.


Assuntos
Imagem de Tensor de Difusão , Ataxias Espinocerebelares , Cerebelo , Humanos , Imageamento por Ressonância Magnética , Linhagem , Ataxias Espinocerebelares/diagnóstico por imagem , Ataxias Espinocerebelares/genética
4.
Front Oncol ; 11: 687127, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34322388

RESUMO

The diagnostic efficiency of radiation encephalopathy (RE) remains heterogeneous, and prediction of RE is difficult at the pre-symptomatic stage. We aimed to analyze the whole-brain resting-state functional connectivity density (FCD) of individuals with pre-symptomatic RE using multivariate pattern analysis (MVPA) and explore its prediction efficiency. Resting data from NPC patients with nasopharyngeal carcinoma (NPC; consisting of 20 pre-symptomatic RE subjects and 26 non-RE controls) were collected in this study. We used MVPA to classify pre-symptomatic RE subjects from non-RE controls based on FCD maps. Classifier performances were evaluated by accuracy, sensitivity, specificity, and area under the characteristic operator curve. Permutation tests and leave-one-out cross-validation were applied for assessing classifier performance. MVPA was able to differentiate pre-symptomatic RE subjects from non-RE controls using global FCD as a feature, with a total accuracy of 89.13%. The temporal lobe as well as regions involved in the visual processing system, the somatosensory system, and the default mode network (DMN) revealed robust discrimination during classification. Our findings suggest a good classification efficiency of global FCD for the individual prediction of RE at a pre-symptomatic stage. Moreover, the discriminating regions may contribute to the underlying mechanisms of sensory and cognitive disturbances in RE.

5.
Biosens Bioelectron ; 177: 112977, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33434779

RESUMO

Assays for detecting tetanus toxoid are of great significance to be applied in the research of the safety testing of tetanus vaccine. Currently, guinea pigs or mice are usually used to evaluate the toxicity in these assays. Herein, a facile and quick biomineralization process was carried out to generate tetanus human immunoglobulin G (Tet-IgG)-functionalized Au nanoclusters (Tet-IgG-AuNCs). The obtained Tet-IgG-AuNCs exhibited strong red emission with a photoluminescence quantum yield of 13%. Based on surface plasmon resonance measurements, the apparent dissociation constant of the Tet-IgG-AuNC-tetanus toxoid complexes was measured to be 2.27 × 10-8 M. A facile detection approach was developed using a fluorescent Tet-IgG-AuNC-based immunochromatography test strip. By utilizing the high-brightness fluorescent Tet-IgG-AuNCs, this immunosensor showed favorable sensitivity with a detection limit at the level of 0.03 µg/mL. Further results demonstrated that this assay can reliably detect tetanus toxoid and therefore might provide a novel method to replace animal tests for the quantification of tetanus toxicity. Moreover, the antibody-AuNC-based immunochromatography test strip platform serves as a promising candidate to develop new approaches for detecting targeted antigens and biological events of interest.


Assuntos
Técnicas Biossensoriais , Tétano , Animais , Cromatografia de Afinidade , Cobaias , Humanos , Imunoensaio , Imunoglobulina G , Camundongos , Toxoide Tetânico
6.
Mikrochim Acta ; 186(12): 778, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31728642

RESUMO

Platinum nanoparticles (Pt NPs) covered with a bovine serum albumin scaffold and a particle size of 1.5 nm (BSA-PtS NPs) are shown to display enhanced multiple enzyme-mimicking activities including peroxidase, oxidase, and catalase-like activities. The peroxidase-like activity is characterized by robustness and low signal background. BSA-PtS NPs were used to design colorimetric assays for H2O2 and glucose. H2O2 latter reacts with 3,3',5,5'-tetramethylbenzidine in the presence of BSA-PtS NPs to form a blue product with an absorption maximum at 652 nm. The assay works in the 5-250 µM H2O2 concentration range. The glucose assay is based on its glucose oxidase-catalyzed oxidation to produce gluconic acid and H2O2 which then is colorimetrically quantified. Response is linear in the 10-120 µM glucose concentration range, and the detection limit is 2 µM (at S/N = 3). The method correlates well with the glucose standard method (R2 = 0.997 in the 95% confidence interval) which confirms that glucose in human serum has been successfully detected. Graphical abstractImproved enzymatic assay for hydrogen peroxide and glucose by exploiting the enzyme-mimicking properties of BSA-coated platinum nanoparticles.


Assuntos
Glicemia/análise , Colorimetria/métodos , Peróxido de Hidrogênio/análise , Nanopartículas Metálicas/química , Animais , Benzidinas/química , Catálise , Bovinos , Corantes/química , Glucose Oxidase/química , Humanos , Peróxido de Hidrogênio/química , Limite de Detecção , Oxirredução , Oxirredutases/química , Tamanho da Partícula , Platina/química , Soroalbumina Bovina/química
7.
Anal Chem ; 91(6): 4039-4046, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30793603

RESUMO

Although it has been demonstrated that rare-earth elements (REEs) disturb and alter the catalytic activity of numerous natural enzymes, their effects on nanomaterial-based artificial enzymes (nanozymes) have been seldom explored. In this work, the influence of REEs on the peroxidase-like activity of bare gold nanoparticles (GNPs) is investigated for the first time, and a new type of Ce3+-activated peroxidase mimetic activity of GNPs is obtained. The introduced Ce3+ can be bound to the bare GNP surface rapidly through electrostatic attraction, after which it donates its electron to the bare GNP. As H2O2 is a good electron scavenger, more •OH radicals are generated on the surfaces of the bare GNPs, which can considerably enhance TMB oxidation. Due to its redox cycling ability, the activation effect of Ce3+ is proved to be more efficient in comparison to those of the other reported metal ion activators (e.g., Bi3+, Hg2+, and Pb2+). In addition, it is determined that Ce3+ should directly contact with the gold core to trigger its activation effect. When the surface states of the bare GNPs are altered, the Ce3+-stimulated effect is strongly inhibited. Furthermore, a novel colorimetric method for Ce3+ is developed, on the basis of its enhancing effect on the peroxidase mimetic activity of bare GNPs. The sensitivity of this newly developed method for Ce3+ is excellent with a limit of detection as low as 2.2 nM. This study not only provides an effective GNP-based peroxidase mimic but also contributes in realizing new applications for nanozymes.

8.
ACS Sens ; 4(2): 344-352, 2019 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-30652857

RESUMO

In this study, on the basis of the biomineralization capability of urease, a facile, one-step, and green synthetic method has been proposed for the fabrication of gold nanoclusters (AuNCs). The prepared urease-encapsulated AuNCs (U-AuNCs) exhibited strong red fluorescence emission (λem = 630 nm) with a quantum yield as high as 17%. Interestingly, at a low concentration, the U-AuNC solution was found to be a dual-emissive system with the blue emission of the dityrosine (diTyr) residues of urease and the red emission of the embedded AuNCs. Further experiments demonstrated that p-nitrophenol (PNP) can selectively suppress the 410 nm emission of the diTyr residues of U-AuNCs without affecting the red emission of the U-AuNCs. The fluorescence quenching mechanism between U-AuNCs and PNP was systematically studied, and the leading role of the inner filter effect (IFE) was identified. Additionally, based on the sulfatase-catalyzed hydrolysis of p-nitrophenyl sulfate (PNPS) to release PNP, a self-referenced ratiometric detection method for sulfatase, which plays a crucial role in sulfur cycling, degradation of sulfated glycosaminoglycans and glycolipids, and extracellular remodeling of sulfated glycosaminoglycans, was developed by using dual-emissive U-AuNCs as the signal readout, in which the diTyr residues served as the probe and the AuNCs functioned as the internal reference. This IFE-based ratiometric sensing strategy showed a good linear relationship over the range of 0.01-1 U/mL ( R2 = 0.997). The detection limit for sulfatase activity was 0.01 U/mL. The developed protocol was successfully used to detect sulfatase activity in human serum samples. The simplicity, rapidity, low cost, high credibility, good reproducibility, and excellent selectivity of the detection platform serve as an inspiration for further applications of fluorescent AuNCs in chemo/biosensing.


Assuntos
Ensaios Enzimáticos/métodos , Ouro/química , Nanopartículas Metálicas/química , Sulfatases/metabolismo , Urease/química , Canavalia/enzimologia , Hidrólise , Limite de Detecção , Espectrometria de Fluorescência
9.
Arch Insect Biochem Physiol ; 100(1): e21511, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30417456

RESUMO

The Silkworm Bombyx mori is an important insect in terms of economics and a model organism with a complete metamorphosis. The economic importance of silkworms is dependent on the functions of the silkgland, a specialized organ that synthesizes silk proteins. The silk gland undergoes massive degeneration during the larval to pupal stage, which involves in cell apoptosis. In this paper, high throughput sequencing was used to detect the expression of messenger RNA (mRNA), long noncoding RNA (lncRNA), and microRNA (miRNA) from silk glands of Day 3 in the fifth instar larvae (L5D3) and the spinning 36h (sp36h). We analyzed the Gene Ontology (GO) functions of target genes of the differentially expressed lncRNAs and miRNAs. We investigated the regulations of mRNA, lncRNA, and miRNA on silk gland apoptosis in L5D3 and sp36h. In total, 10,947 lncRNAs were detected in the silk gland and the index number TCONS-00021360 lncRNA may be involved in the process of apoptosis. In addition, 344 miRNAs targeted 285 mRNAs were related to the death process under GO entry. The results indicated that miRNAs play an important role in the molecular regulation of the silk gland apoptosis compared with that of lncRNAs. Finally, we screened 746 lncRNAs and 20 miRNAs that might interact with BmDredd, and drew an interaction network among them.


Assuntos
Estruturas Animais/metabolismo , Apoptose/fisiologia , Bombyx/fisiologia , RNA/metabolismo , Animais , Regulação da Expressão Gênica/fisiologia , RNA/genética
10.
Colloids Surf B Biointerfaces ; 159: 613-619, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28858664

RESUMO

Fullerenes with novel structures find numerous potential applications, particularly in the fields of biology and pharmaceutics. Among various fullerene derivatives, those exhibiting amphiphilic character and capable of self-assembly into vesicles are particularly interesting, being suitable for delayed drug release. Herein, we report the synthesis and self-assembly of biocompatible hollow nanovesicles with bilayer shells from amphiphilic functionalized fullerenes C60R5Cl (R=methyl ester of 4-aminobutyric/glutamic acid or phenylalanine). The thus prepared vesicles exhibit sizes of 80-135nm (depending on R) and can be used as delayed-release carriers of anti-cancer drugs such as 5-fluorouracil, cyclophosphamide, and cisplatin, with the time of 5-fluorouracil release from drug-containing vesicles exceeding that of non-encapsulated forms by a factor of three. We further reveal the effect of R on the loading amount and release rate/amount of vesicle-encapsulated drugs, demonstrating a potential pharmaceutical application of the prepared nanovesicles depending on the nature of R.


Assuntos
Aminoácidos/química , Antineoplásicos/química , Cloretos/química , Liberação Controlada de Fármacos , Fulerenos/química , Cisplatino/química , Ciclofosfamida/química , Sistemas de Liberação de Medicamentos/métodos , Fluoruracila/química
11.
PLoS One ; 12(1): e0169404, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28068357

RESUMO

Silk glands (SGs) undergo massive apoptosis driven degeneration during the larval-pupal transformation. To better understand this event on molecular level, we investigated the expression of apoptosis-related genes across the developmental transition period that spans day 4 in the fifth instar Bombyx mori larvae to day 2 pupae. Increases in the expression of BmDredd (an initiator caspase homolog) closely followed the highest BmEcR expression and resembled the expression trend of BmIcE. Simultaneously, we found that BmDredd expression was significantly higher in SG compared to other tissues at 18 h post-spinning, but reduced following injection of the apoptosis inhibitor (Z-DEVD-fmk). Furthermore, BmDredd expression correlated with changes of caspase3-like activities in SG and RNAi-mediated knockdown of BmDredd delayed SG apoptosis. Moreover, caspase3-like activity was increased in SG by overexpression of BmDredd. Taken together, the results suggest that BmDredd plays a critical role in SG apoptosis.


Assuntos
Apoptose/genética , Bombyx/fisiologia , Caspases/genética , Proteínas de Insetos/genética , Seda/metabolismo , Animais , Inibidores de Caspase/farmacologia , Caspases/metabolismo , Expressão Gênica/efeitos dos fármacos , Proteínas de Insetos/metabolismo , Metamorfose Biológica
12.
Arch Insect Biochem Physiol ; 93(3): 160-173, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27558456

RESUMO

The apoptosis mechanisms in mammals were investigated relatively clearly. However, little is known about how apoptosis is achieved at a molecular level in silkworm cells. We cloned a caspase homologous gene named BmDredd (where Bm is Bombyx mori and Dredd is death-related ced-3/Nedd2-like caspase) in BmN cells from the ovary of Bm and analyzed its biological information. We constructed the N-terminal, C-terminal, and overexpression vector of BmDredd, respectively. Our results showed that the transcriptional expression level of BmDredd was increased in the apoptotic BmN cells. Furthermore, overexpression of BmDredd increased the caspase-3/7 activity. Simultaneously, RNAi of BmDredd could save BmN cells from apoptosis. The immunofluorescence study showed that BmDredd located at the cytoplasm in normal cell otherwise is found at the nucleus when cells undergo apoptosis. Moreover, we quantified the transcriptional expressions of apoptosis-related genes including BmDredd, BmDaxx (where Daxx is death-domain associated protein), BmCide-b (where Cide-b is cell death inducing DFF45-like effector), BmFadd (Fadd is fas-associated via death domain), and BmCreb (where Creb is cAMP-response element binding protein) in BmN cells with dsRNA interferences to detect the molecular mechanism of apoptosis. In conclusion, BmDredd may function for promoting apoptosis and there are various regulatory interactions among these apoptosis-related genes.


Assuntos
Apoptose , Bombyx/fisiologia , Caspases/genética , Proteínas de Insetos/genética , Sequência de Aminoácidos , Animais , Bombyx/genética , Caspases/química , Caspases/metabolismo , Linhagem Celular , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Feminino , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Masculino , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência
13.
Insect Sci ; 23(1): 28-36, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25409652

RESUMO

PLA2 enzyme hydrolyzes arachidonic acid, and other polyunsaturated fatty acids, from the sn-2 position to release free arachidonic acid and a lysophospholipid. Previous studies reported that the PLA2 in invertebrate organisms participates in lipid signaling molecules like arachidonic acid release in immune-associated tissues like hemocytes and fat bodies. In the present study, we cloned the BmPLA2 gene from fat body tissue of silkworm Bombyx mori, which has a total sequence of 1.031 kb with a 31.90 kDa protein. In silico results of BmPLA2 indicated that the protein has a putative WD40 conserved domain and its phylogeny tree clustered with Danaus plexippus species. We investigated the transcriptional expression in development stages and tissues. The highest expression of BmPLA2 was screened in fat body among the studied tissues of third day fifth instar larva, with a high expression on third day fifth instar larva followed by a depression of expression in the wandering stage of the fifth instar larva. The expression of BmPLA2 in female pupa was higher than that of male pupa. Our RNAi-mediated gene silencing results showed highest reduction of BmPLA2 expression in post-24 h followed by post-48 and post-72 h. The BmPLA2-RNAi larvae and pupa could be characterized by pharate adult lethality and underdevelopment. The phenotypic characters of fat body cells in RNAi-induced larva implied that BmPLA2 affects the metabolic functions of fat body tissue in silkworm Bombyx mori.


Assuntos
Bombyx/metabolismo , Sequência Conservada , Corpo Adiposo/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Clonagem Molecular , Metabolismo Energético , Corpo Adiposo/citologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Masculino , Dados de Sequência Molecular , Fenótipo , Estrutura Terciária de Proteína , Pupa/crescimento & desenvolvimento , Pupa/metabolismo , Transcrição Gênica
14.
Arch Insect Biochem Physiol ; 90(2): 59-69, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25917878

RESUMO

Salivary gland secretion is altered in Drosophila embryos with loss of function of the sage gene. Saliva has a reduced volume and an increased electron density according to transmission electron microscopy, resulting in regions of tube dilation and constriction with intermittent tube closure. However, the precise functions of Bmsage in silkworm (Bombyx mori) are unknown, although its sequence had been deposited in SilkDB. From this, Bmsage is inferred to be a transcription factor that regulates the synthesis of silk fibroin and interacts with another silk gland-specific transcription factor, namely, silk gland factor-1. In this study, we introduced a germline mutation of Bmsage using the Cas9/sgRNA system, a genome-editing technology, resulting in deletion of Bmsage from the genome of B. mori. Of the 15 tested samples, seven displayed alterations at the target site. The mutagenesis efficiency was about 46.7% and there were no obvious off-target effects. In the screened homozygous mutants, silk glands developed poorly and the middle and posterior silk glands (MSG and PSG) were absent, which was significantly different from the wild type. The offspring of G0 mosaic silkworms had indel mutations causing 2- or 9-bp deletions at the target site, but exhibited the same abnormal silk gland structure. Mutant larvae containing different open-reading frames of Bmsage had the same silk gland phenotype. This illustrated that the mutant phenotype was due to Bmsage knockout. We conclude that Bmsage participates in embryonic development of the silk gland.


Assuntos
Bombyx/fisiologia , Glândulas Exócrinas/embriologia , Proteínas de Insetos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Bombyx/embriologia , Bombyx/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Embrião não Mamífero , Glândulas Exócrinas/fisiologia , Feminino , Proteínas de Insetos/genética , Larva/genética , Larva/crescimento & desenvolvimento , Mutação , Fatores de Transcrição/genética
15.
Arch Insect Biochem Physiol ; 89(2): 98-110, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25735242

RESUMO

Rab3 GTPases are known to play key a role in vesicular trafficking, and express highest in brain and endocrine tissues. In mammals, Rab3 GTPases are paralogs unlike in insect. In this study, we cloned Rab3 from the silk gland tissue of silkworm Bombyx mori, and identified it as BmRab3. Our in silico analysis indicated that BmRab3 is an isoform with a theoretical isoelectric point and molecular weight of 5.52 and 24.3 kDa, respectively. Further, BmRab3 showed the C-terminal hypervariability for GGT2 site but having two other putative guanine nucleotide exchange factor/GDP dissociation inhibitor interaction sites. Multiple alignment sequence indicated high similarities of BmRab3 with Rab3 isoforms of other species. The phylogeny tree showed BmRab3 clustered between the species of Tribolium castaneum and Aedes aegypti. Meanwhile, the expression analysis of BmRab3 showed the highest expression in middle silk glands (MSGs) than all other tissues in the third day of fifth-instar larva. Simultaneously, we showed the differential expression of BmRab3 in the early instar larva development, followed by higher expression in male than female pupae. In vivo dsRNA interference of BmRab3 reduced the expression of BmRab3 by 75% compared to the control in the MSGs in the first day. But as the worm grew to the third day, the difference of BmRab3 between knockdown and control was only about 10%. The knockdown later witnessed underdevelopment of the larvae and pharate pupae lethality in the overall development of silkworm B. mori L.


Assuntos
Bombyx/fisiologia , Proteínas de Insetos/fisiologia , Proteínas rab3 de Ligação ao GTP/fisiologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Feminino , Técnicas de Silenciamento de Genes , Larva/fisiologia , Masculino , Dados de Sequência Molecular , Pupa/metabolismo , Interferência de RNA , Análise de Sequência de DNA
16.
Insect Sci ; 22(5): 587-96, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25154865

RESUMO

Hedgehog (Hh) signals regulate invertebrate and vertebrate development, yet the role of the pathway in adipose development remains poorly understood. In this report, we found that Hh pathway components are expressed in the fat body of silkworm larvae. Functional analysis of these components in a BmN cell line model revealed that activation of the Hh gene stimulated transcription of Hh pathway components, but inhibited the expression of the adipose marker gene AP2. Conversely, specific RNA interference-mediated knockdown of Hh resulted in increased AP2 expression. This further showed the regulation of Hh signal on the adipose marker gene. In silkworm larval models, enhanced adipocyte differentiation and an increase in adipocyte cell size were observed in silkworms that had been treated with a specific Hh signaling pathway antagonist, cyclopamine. The fat-body-specific Hh blockade tests were consistent with Hh signaling inhibiting silkworm adipogenesis. Our results indicate that the role of Hh signaling in inhibiting fat formation is conserved in vertebrates and invertebrates.


Assuntos
Bombyx/metabolismo , Proteínas Hedgehog/metabolismo , Adipócitos/fisiologia , Adipogenia/genética , Animais , Bombyx/genética , Linhagem Celular , Corpo Adiposo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Hedgehog/antagonistas & inibidores , Larva/metabolismo , Interferência de RNA , Transdução de Sinais/fisiologia , Fatores de Transcrição/genética , Alcaloides de Veratrum/farmacologia
17.
Mol Biol Rep ; 41(12): 8247-54, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25200437

RESUMO

The Bombyx mori nucleopolyhedrovirus (BmNPV) is one of the most destructive diseases in silkworm, which has caused the main damage to sericulture industry. In this study, we developed a system of RNAi to prevent the BmNPV infection using the piggyBac transposon-derived targeting short hairpin RNA (shRNA) interference. The shRNAs targeting the genes of i.e.-1, lef-1, lef-2 and lef-3 of BmNPV were designed and used to inhibit the intracellular replication or multiplication of BmNPV in Bm cells. The highest activity was presented in the shRNA targeting the i.e.-1c of BmNPV, of which the inhibition rate reached 94.5 % in vitro. Further a stable Bm cell line of piggyBac transposon-derived targeting shRNA interference against BmNPV was established, which has a highly efficacious suppression on virus proliferation. These results indicated that the recombinant shRNA expression system was a useful tool for resistance to BmNPV in vitro. The approach by recombinant shRNAs opens a door of RNAi technology as a strategy that offering technically simpler, cheaper, and quicker gene knockdown for promising research and biotechnology application on silkworm lethal diseases.


Assuntos
Bombyx/virologia , Técnicas de Silenciamento de Genes/métodos , Nucleopoliedrovírus/fisiologia , Animais , Elementos de DNA Transponíveis , Genes Virais , Nucleopoliedrovírus/genética , RNA Interferente Pequeno , Replicação Viral
18.
Arch Insect Biochem Physiol ; 84(2): 78-89, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24038161

RESUMO

Molting in insects is regulated by molting hormones (ecdysteroids), which are also crucial to insect growth, development, and reproduction etc. The decreased ecdysteroid in titre results from enhanced ecdysteroid inactivation reactions including the formation of 3-epiecdyson under ecdysone oxidase and 3-dehydroecdysone 3α-reductase (3DE 3α-reductase). In this paper, we cloned and characterized 3-dehydroecdysone 3α-reductase (3DE 3α-reductase) in different tissues and developing stage of the silkworm, Bombyx mori L. The B. mori 3DE 3α-reductase cDNA contains an ORF 783 bp and the deduced protein sequence containing 260 amino acid residues. Analysis showed the deduced 3DE 3α-reductase belongs to SDR family, which has the NAD(P)-binding domain. Using the Escherichia coli, a high level expression of a fusion polypeptide band of approx. 33 kDa was observed. High transcription of 3DE 3α-reductase was mainly presented in the midgut and hemolymph in the third day of fifth instar larvae in silkworm. The expression of 3DE 3α-reductase at different stages of larval showed that the activity in the early instar was high, and then reduced in late instar. This is parallel to the changes of molting hormone titer in larval. 3DE 3α-reductase is key enzyme in inactivation path of ecdysteroid. The data elucidate the regulation of 3DE 3α-reductase in ecdyteroid titer of its targeting organs and the relationship between the enzyme and metamorphosis.


Assuntos
3-Hidroxiesteroide Desidrogenases/genética , Bombyx/metabolismo , Ecdisona/metabolismo , 3-Hidroxiesteroide Desidrogenases/metabolismo , Sequência de Aminoácidos , Animais , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Clonagem Molecular , DNA Complementar/genética , Ecdisona/genética , Ecdisteroides , Escherichia coli , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Larva/metabolismo , Dados de Sequência Molecular , Muda
19.
Mol Biol Rep ; 40(6): 4115-22, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23640098

RESUMO

Insect molting is an important developmental process of metamorphosis, which is initiated by molting hormone. Molting includes the activation of dermal cells, epidermal cells separation, molting fluid secretion, the formation of new epidermis and old epidermis shed and other series of continuous processes. Polyphenol oxidases, dopa decarboxylase and acetyltransferase are necessary enzymes for this process. Traditionally, the dopa decarboxylase (BmDdc) was considered as an enzyme for epidermal layer's tanning and melanization. This work suggested that dopa decarboxylase is one set of the key enzymes in molting, which closely related with the regulation of ecdysone at the time of biological molting processes. The data showed that the expression peak of dopa decarboxylase in silkworm is higher during molting stage, and decreases after molting. The significant increase in the ecdysone levels of haemolymph was also observed in the artificially fed silkworm larvae with ecdysone hormone. Consistently, the dopa decarboxylase expression was significantly elevated compared to the control. BmDdc RNAi induced dopa decarboxylase expression obviously declined in the silkworm larvae, and caused the pupae appeared no pupation or incomplete pupation. BmDdc was mainly expressed and stored in the peripheral plasma area near the nucleus in BmN cells. In larval, BmDdc was mainly located in the brain and epidermis, which is consisted with its function in sclerotization and melanization. Overall, the results described that the dopa decarboxylase expression is regulated by the molting hormone, and is a necessary enzyme for the silkworm molting.


Assuntos
Bombyx/enzimologia , Dopa Descarboxilase/genética , Ecdisona/farmacologia , Animais , Western Blotting , Bombyx/efeitos dos fármacos , Bombyx/genética , Bombyx/crescimento & desenvolvimento , Dopa Descarboxilase/metabolismo , Ecdisona/administração & dosagem , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/genética , Especificidade de Órgãos/efeitos dos fármacos , Especificidade de Órgãos/genética , Transporte Proteico/efeitos dos fármacos , RNA de Cadeia Dupla/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
20.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 9): o2398, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22065510

RESUMO

In the title mol-ecule, C(25)H(30)O(4), the two cyclo-hexene rings adopt envelope conformations. The two hy-droxy groups are involved in the formation of intra-molecular O-H⋯O hydrogen bonds. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules related by translation along the axis a into chains.

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