Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
Angew Chem Int Ed Engl ; : e202410881, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-39126280

RESUMO

Industrial fermentation applications typically require enzymes that exhibit high stability and activity at high temperatures. However, efforts to simultaneously improve these properties are usually limited by a trade-off between stability and activity. This report describes a computational strategy to enhance both activity and thermal stability of the mesophilic organophosphate-degrading enzyme, methyl parathion hydrolase (MPH). To predict hotspot mutation sites, we assembled a library of features associated with the target properties for each residue and then prioritized candidate sites by hierarchical clustering. Subsequent in silico screening with multiple algorithms to simulate selective pressures yielded a subset of 23 candidate mutations. Iterative parallel screening of mutations that improved thermal stability and activity yielded, MPHase-m5b, which exhibited 13.3 °C higher Tm and 4.2 times higher catalytic activity than wild-type (WT) MPH over a wide temperature range. Systematic analysis of crystal structures, molecular dynamics (MD) simulations, and Quantum Mechanics/Molecular Mechanics (QM/MM) calculations revealed a wider entrance to the active site that increased substrate access with an extensive network of interactions outside the active site that reinforced αß/ßα sandwich architecture to improve thermal stability. This study thus provides an advanced, rational design framework to improve efficiency in engineering highly active, thermostable biocatalysts for industrial applications.

2.
Clin Chem Lab Med ; 60(5): 748-755, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35212492

RESUMO

OBJECTIVES: Platelet clumps present in anticoagulant specimens may generate a falsely decreased platelet count and lead to an incorrect diagnosis. A clear understanding of the ability of a haematology analyser (HA) to detect platelet clumps is important for routine work in the clinical laboratory. METHODS: Citrate-anticoagulated whole-blood samples were collected from various patients as a negative group. Adenosine diphosphate (ADP)-induced platelet aggregation was performed on those negative samples to mimic platelet-clump-containing (positive) samples. The 'platelet clumps' and 'platelet abnormal' flags generated by the Sysmex XN-10 instrument were used to assess the flagging performance of this HA and demonstrate its flagging features. The complete blood count (CBC) results of paired negative and positive samples were compared to evaluate the impact of platelet clumps on the CBC parameters. RESULTS: A total of 187 samples were eligible for this study. The total accuracy, sensitivity, and specificity of the platelet clumps flag were 0.786, 0.626, and 0.947, respectively. The total accuracy, sensitivity, and specificity of the platelet abnormal flag were 0.631, 0.348, and 0.914, respectively. A separate assessment focusing on the positive samples with low platelet counts showed that the total sensitivities of the platelet clumps and platelet abnormal flags were 0.801 and 1.000, respectively. Platelet clumps may interfere with the leukocyte count and with platelet and erythrocyte indices. CONCLUSIONS: Platelet clumps can influence not only platelet indices but also leukocyte and erythrocyte counts. The Sysmex XN-10 instrument is sensitive to positive samples with low platelet counts but insensitive to those with high platelet counts.


Assuntos
Hematologia , Leucócitos , Contagem de Células Sanguíneas/métodos , Hematologia/métodos , Humanos , Contagem de Leucócitos , Contagem de Plaquetas
3.
Bull Entomol Res ; 112(2): 171-178, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34365981

RESUMO

Cytochrome P450 monooxygenases play a key role in pest resistance to insecticides by detoxification. Four new P450 genes, CYP6AS160, CYP6AS161, CYP4AB73 and CYP4G232 were identified from Solenopsis invicta. CYP6AS160 was highly expressed in the abdomen and its expression could be induced significantly with exposure to fipronil, whereas CYP4AB73 was not highly expressed in the abdomen and its expression could not be significantly induced following exposure to fipronil. Expression levels of CYP6AS160 and CYP4AB73 in workers were significantly higher than that in queens. RNA interference-mediated gene silencing by feeding on double-stranded RNA (dsRNA) found that the levels of this transcript decreased (by maximum to 64.6%) when they fed on CYP6AS160-specific dsRNA. Workers fed dsCYP6AS160 had significantly higher mortality after 24 h of exposure to fipronil compared to controls. Workers fed dsCYP6AS160 had reduced total P450 activity of microsomal preparations toward model substrates p-nitroanisole. However, the knockdown of a non-overexpressed P450 gene, CYP4AB73 did not lead to an increase of mortality or a decrease of total P450 activity. The knockdown effects of CYP6AS160 on worker susceptibility to fipronil, combined with our other findings, indicate that CYP6AS160 is responsible for detoxification of fipronil. Feeding insects dsRNA may be a general strategy to trigger RNA interference and may find applications in entomological research and in the control of insect pests in the field.


Assuntos
Formigas , Inseticidas , Animais , Formigas/genética , Inseticidas/farmacologia , Pirazóis , Interferência de RNA , RNA de Cadeia Dupla
4.
Bull Entomol Res ; 112(5): 646-655, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35172917

RESUMO

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.


Assuntos
Afídeos , Inseticidas , Animais , Inseticidas/farmacologia , Afídeos/fisiologia , Tiametoxam/farmacologia , Resistência a Inseticidas/genética , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia
5.
Clin Chem Lab Med ; 59(7): 1289-1297, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-33660491

RESUMO

OBJECTIVES: A sample with a blood clot may produce an inaccurate outcome in coagulation testing, which may mislead clinicians into making improper clinical decisions. Currently, there is no efficient method to automatically detect clots. This study demonstrates the feasibility of utilizing machine learning (ML) to identify clotted specimens. METHODS: The results of coagulation testing with 192 clotted samples and 2,889 no-clot-detected (NCD) samples were retrospectively retrieved from a laboratory information system to form the training dataset and testing dataset. Standard and momentum backpropagation neural networks (BPNNs) were trained and validated using the training dataset with a five-fold cross-validation method. The predictive performances of the models were then assessed based on the testing dataset. RESULTS: Our results demonstrated that there were intrinsic distinctions between the clotted and NCD specimens regarding differences in the testing results and the separation of the groups (clotted and NCD) in the t-SNE analysis. The standard and momentum BPNNs could identify the sample status (clotted and NCD) with areas under the ROC curves of 0.966 (95% CI, 0.958-0.974) and 0.971 (95% CI, 0.9641-0.9784), respectively. CONCLUSIONS: Here, we have described the application of ML algorithms in identifying the sample status based on the results of coagulation testing. This approach provides a proof-of-concept application of ML algorithms to evaluate the sample quality, and it has the potential to facilitate clinical laboratory automation.


Assuntos
Laboratórios Clínicos , Doenças não Transmissíveis , Algoritmos , Testes de Coagulação Sanguínea , Humanos , Aprendizado de Máquina , Estudos Retrospectivos
6.
Pestic Biochem Physiol ; 177: 104885, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34301353

RESUMO

Imidacloprid is a neonicotinoid that targets sucking pests, such as aphids and the green leaf bug and has been widely applied in wheat fields to control wheat aphids in China. To investigate the involvement of miRNAs in imidacloprid resistance, we sequenced small RNA libraries of Sitobion miscanthi Fabricius, across two different treatments using Illumina short-read sequencing technology. As a result, 265 microRNAs (miRNAs), of which 242 were known and 23 were novel, were identified. Quantitative analysis of miRNA levels showed that 23 miRNAs were significantly up-regulated, and 54 miRNAs were significantly down-regulated in the nymphs of S. miscanthi treated with imidacloprid in comparison with those of the control. Modulation of the abundances of differentially expressed miRNAs, smi-miR-316, smi-miR-1000, and smi-miR-iab-4 by the addition of the corresponding antagomir/inhibitor to the artificial diet significantly changed the susceptibility of S. miscanthi to imidacloprid. Subsequently, the post-transcriptional regulatory mechanism was conducted, smi-miR-278 and smi-miR-316 were confirmed to be participated in the post-transcriptional regulation of nAChRα1A and CYP4CJ6, respectively. The results suggested that miRNAs differentially expressed in response to imidacloprid could play a critical regulatory role in the metabolism of S. miscanthi to imidacloprid.


Assuntos
Afídeos , MicroRNAs , Animais , Afídeos/genética , China , Perfilação da Expressão Gênica , MicroRNAs/genética , Neonicotinoides/toxicidade , Nitrocompostos
7.
BMC Genet ; 21(1): 93, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32859149

RESUMO

BACKGROUND: Waterlogging is one of the most serious abiotic stresses affecting wheat-growing regions in China. Considerable differences in waterlogging tolerance have been found among different wheat varieties, and the mechanisms governing the waterlogging tolerance of wheat seeds during germination have not been elucidated. RESULTS: The results showed no significant difference between the germination rate of 'Bainong 207' (BN207) (after 72 h of waterlogging treatment) and that of the control seeds. However, the degree of emulsification and the degradation rate of endosperm cells under waterlogging stress were higher than those obtained with the control treatment, and the number of amyloplasts in the endosperm was significantly reduced by waterlogging. Transcriptomic data were obtained from seed samples (a total of 18 samples) of three wheat varieties, 'Zhoumai 22' (ZM22), BN207 and 'Bainong 607' (BN607), subjected to the waterlogging and control treatments. A comprehensive analysis identified a total of 2775 differentially expressed genes (DEGs). In addition, an analysis of the correlations among the expression difference levels of DEGs and the seed germination rates of the three wheat varieties under waterlogging stress revealed that the relative expression levels of 563 and 398 genes were positively and negatively correlated with the germination rate of the wheat seeds, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the difference in the waterlogging tolerance among the three wheat varieties was related to the abundance of key genes involved in the glycolysis pathway, the starch and sucrose metabolism pathway, and the lactose metabolism pathway. The alcohol dehydrogenase (ADH) gene in the endosperm of BN607 was induced immediately after short-term waterlogging, and the energy provided by the glycolysis pathway enabled the BN607 seeds to germinate as early as possible; in addition, the expression of the AP2/ERF transcription factor was upregulated to further enhance the waterlogging tolerance of this cultivar. CONCLUSIONS: Taken together, the results of this study help elucidate the mechanisms through which different wheat varieties respond to waterlogging stress during germination.


Assuntos
Germinação , Sementes/fisiologia , Estresse Fisiológico , Transcriptoma , Triticum/genética , Metabolismo dos Carboidratos/genética , Inundações , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Fenótipo , Triticum/fisiologia
8.
Pestic Biochem Physiol ; 169: 104649, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32828367

RESUMO

Spodoptera litura is a destructive agricultural pest and has evolved resistance to multiple insecticides, especially pyrethroids. At present, the resistance mechanism to pyrethroids remains unclear. Four field-collected populations, namely CZ, LF, NJ and JD, were identified to have high resistance to pyrethroids comparing to pyrethroid-susceptible population (GX), with resistant ratio ranging from 11.5- to 9123.5-fold. To characterize pyrethroid resistance mechanism, the transcriptomes between two pyrethroid-resistant (LF and NJ) and a pyrethroid-susceptible (GX) populations were compared by RNA-sequencing. Results showed that multiple differentially expressed genes were enriched in metabolism-related GO terms and KEGG pathways. 35 up-regulated metabolism-related unigenes were selected to verify by qRT-PCR and 15 unigenes, including 4 cytochrome P450s (P450s), 5 glutathione S-transferase (GSTs), 1 UDP-glycosyltransferase (UGT), 4 carboxylesterases (COEs) and 1 and ATP-binding cassette transporters (ABC), were all up-regulated in the four pyrethroid-resistant populations. The expression levels of CYP3 and GST3, which were annotated as CYP6A13 and GSTE1, respectively, showed positive correlation with their pyrethroid resistance levels among the four pyrethroid-resistant populations. While the expression levels of CYP5, CYP12, COE4 and ABC5 showed good correlation with their pyrethroid resistance levels in at least three populations. UGT5 had the highest expression level among the tested UGT genes in the four pyrethroid-resistant populations. RNAi mediated silencing of CYP6 increased the cumulative mortality treated by beta cypermethrin and cyhalothrin significantly, while silencing of GST3 increased the cumulative mortality treated by fenvalerate significantly. CYP3, CYP5, CYP6, CYP12, GST3, COE4, UGT5 and ABC5 play important roles in pyrethroid resistance among the four pyrethroid-resistant populations. Our work provides a valuable clue for further study of pyrethroid resistance mechanisms in S. litura.


Assuntos
Inseticidas/farmacologia , Piretrinas , Animais , Perfilação da Expressão Gênica , Resistência a Inseticidas/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos
9.
Andrologia ; 51(8): e13301, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31037746

RESUMO

Male infertility affects approximately half of couples who have difficulty becoming pregnant, and its prevalence is continuously rising. Many studies have been performed using animal testes to reveal the mechanisms of male infertility, but few studies have investigated human testes due to various limitations. The aim of this study was to investigate the gene expression profile of impaired human testes through a meta-analysis of microarray data sets, which was accomplished by using 178 human testis samples and 7 microarray data sets. Impaired testes were categorised into four pathological phenotypes or the normal phenotype based on their Johnsen score. Then, a meta-analysis was performed to screen out the differentially expressed genes (DEGs) in each phenotype. The DEGs were used in a subsequent bioinformatics analysis. Our results identified several novel hub genes and pathways and suggested that G1 mitotic cell cycle arrest was a remarkable feature in pre-meiotic arrest. Furthermore, fifteen p53-interacting proteins, such as ABL1 and HDAC2, whose roles in spermatogenesis have not been well characterised, were selected from the DEGs through a strict screening procedure.


Assuntos
Azoospermia/congênito , Pontos de Checagem da Fase G1 do Ciclo Celular/genética , Espermatogênese/genética , Azoospermia/genética , Azoospermia/patologia , Biologia Computacional , Bases de Dados Genéticas , Conjuntos de Dados como Assunto , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes/genética , Histona Desacetilase 2/genética , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Mapas de Interação de Proteínas/genética , Proteínas Proto-Oncogênicas c-abl/genética , Testículo/patologia , Análise Serial de Tecidos
10.
Insects ; 15(6)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38921143

RESUMO

Bacillus thuringiensis Vip3Aa has been widely used in transgenic crops to resist the erosion of insects. The Scavenger Receptor-C (SR-C) and Fibroblast Growth Factor Receptor (FGFR) of Spodoptera frugiperda (Sf-SR-C and Sf-FGFR) have formerly been identified as the cell receptors of Vip3Aa. However, the interaction mechanism of Vip3Aa binding to Sf-SR-C or Sf-FGFR is still unknown. Here, we purified the MAM domain of Sf-SR-C (Sf-MAM) and the Sf-FGFR ectodomain expressed extracellularly by Sf9 cells. We then solved the crystal structure of the Sf-MAM domain. Structure docking analysis of the Sf-MAM and Vip3Aa C-terminal domain (CTD) excluded the possibility of the two proteins binding. A further surface plasmon resonance (SPR) assay also revealed that the Sf-MAM and Sf-FGFR ectodomain could not bind to the Vip3Aa protein. Our results have raised the urgency of determining the authentic cell receptor for Vip3Aa.

11.
Hortic Res ; 11(9): uhae189, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39247887

RESUMO

Prunus mume (mei), a traditional ornamental plant in China, is renowned for its fragrant flowers, primarily emitted by its petals. However, the cell types of mei petals and where floral volatile synthesis occurs are rarely reported. The study used single-cell RNA sequencing to characterize the gene expression landscape in petals of P. mume 'Fenhong Zhusha' at budding stage (BS) and full-blooming stage (FS). Six major cell types of petals were identified: epidermal cells (ECs), parenchyma cells (PCs), xylem parenchyma cells, phloem parenchyma cells, xylem vessels and fibers, and sieve elements and companion cells complex. Cell-specific marker genes in each cell type were provided. Floral volatiles from mei petals were measured at four flowering development stages, and their emissions increased from BS to FS, and decreased at the withering stage. Fifty-eight differentially expressed genes (DEGs) in benzenoid/phenylpropanoid pathway were screened using bulk RNA-seq data. Twenty-eight DEGs expression increased from BS to FS, indicating that they might play roles in floral volatile synthesis in P. mume, among which PmBAHD3 would participate in benzyl acetate synthesis. ScRNA-seq data showed that 27 DEGs mentioned above were expressed variously in different cell types. In situ hybridization confirmed that PmPAL2, PmCAD1, PmBAHD3,5, and PmEGS1 involved in floral volatile synthesis in mei petals are mainly expressed in EC, PC, and most vascular tissues, consistent with scRNA-seq data. The result indicates that benzyl acetate and eugenol, the characteristic volatiles in mei, are mostly synthesized in these cell types. The first petal single-cell atlas was constructed, offering new insights into the molecular mechanism of floral volatile synthesis.

12.
Ann Clin Biochem ; 60(2): 126-135, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36653307

RESUMO

BACKGROUND: Mainstream haematology analysers (HAs) are reported to have low detection sensitivity for platelet clumps. In this study, a deep learning (DL) algorithm, convolutional neural network (CNN), was implemented to detect platelet clumps. METHODS: Adenosine diphosphate (ADP) was used to induce platelet aggregation to mimic platelet clumps detected (PCD) samples. Six types of leukocyte scattergrams were collected from the Sysmex XN-10. Then, multiple CNNs were trained and validated by scattergrams in a fivefold cross-validation (CV) method. Finally, the CNN model with the best CV accuracy was tested with practical routine work samples. RESULTS: A total of 386 samples (190 PCD and 196 negative samples) and 4253 samples (150 PCD and 4103 negative samples) were eligible for CNN training and practical test, respectively. The CNN with the highest CV accuracy was trained by using scattergrams of side scatter (SSC) vs. forward scatter (FSC) from the white count and nucleated red blood cells (WNR) channel, whose mean area under the curve (AUC), accuracy, specificity and sensitivity were 0.968, 0.940, 0.937 and 0.942, respectively, in the CV. In the practical test, the AUC, accuracy, specificity and sensitivity of the CNN were 0.916, 0.961, 0.860 and 0.965, respectively. The dispersed spots presenting around the leucocytes in the WNR channel may be a sign of platelet clumping. CONCLUSIONS: This study demonstrates that the CNN algorithms can identify platelet clumps based on optical information from dedicated leukocyte channels and has a higher ability to detect platelet clumps than the XN-10 device's internal algorithm under practical circumstances.


Assuntos
Hematologia , Humanos , Hematologia/métodos , Algoritmos
13.
Genes Nutr ; 18(1): 14, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37691106

RESUMO

BACKGROUND: Previous observational studies have shown associations between vitamin Ds and FGIDS[Including irritable bowel syndrome(IBS) and functional dyspepsia(FD)]. However, the association is controversial and the causality remains unknown. In this study, two-sample MR was cited to explore the causal effect on FGIDS caused by vitamin D level and serum 25-hydroxyvitamin D. METHOD: The GWASs of vitaminD and 25-hydroxyvitamin D, with 57-99 strongly related SNPs were all obtained from UK biobank. The GWASs of IBS and FD were obtained from FinnGen biobank with respectively 187,028 and 194,071 participants involved. Fixed-effect inverse variance weighted regression was used to evaluate causal estimates. Other statistical methods such as MR Egger, weighted median estimation, maximum likelihood estimation and penalty-weighted median estimation are also used to verify the accuracy of the main results. RESULTS: Measuring by the IVW method, our research indicated that no causal relationship was detected between vitamin D intake and Functional gastrointestinal disorders [IVW, OR(vitamin D-IBS) = 0.909, 95% CI 0.789-1.053, p = 0.2017); OR(vitamin D-FD) = 1.0662, 95% CI 0.9182-1.2380, p = 0.4000]. As for serum 25-hydroxyvitamin D, no causal relationship was detected on FD(IVW, OR(25-hydroxyvitamin D-FD) = 0.9635, 95% CI 0.8039-1.1546, p = 0.6869). Nevertheless, a negative causal relationship was revealed between 25-hydroxyvitamin D and IBS(IVW, OR(25-hydroxyvitamin D-IBS) = 0.832, 95% CI 0.696-0.995, p = 0.0436). Sensitive analysis supported the main findings but did not suggest bias due to pleiotropy. CONCLUSIONS: Our Mendelian randomization analyses suggest a negative causal relationship between 25-hydroxyvitamin D and IBS. For each additional SD increase of genetically determined 25-hydroxyvitamin D levels, the risk of IBS decreased by 16.8%.

14.
Sci Rep ; 12(1): 10108, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710787

RESUMO

Glutathione S-transferase (GSTs) are members of multifunction enzymes in organisms and mostly known for their roles in insecticide resistance by conjugation. Spodoptera litura (Fabricius) is a voracious agricultural pest widely distributed in the world with high resistance to various insecticides. The function of GSTs in the delta group of S. litura is still lacking. Significantly up-regulation of SlGSTd1 was reported in four pyrethroids-resistant populations and a chlorpyrifos-selected population. To further explore its role in pyrethroids and organophosphates resistance, the metabolism and peroxidase activity of SlGSTD1 were studied by heterologous expression, RNAi, and disk diffusion assay. The results showed that Km and Vmax for 1-chloro-2,4-dinitrobenzene (CDNB) conjugating activity of SlGSTD1were 1.68 ± 0.11 mmol L-1 and 76.0 ± 2.7 nmol mg-1 min-1, respectively. Cyhalothrin, beta-cypermethrin, and chlorpyrifos had an obvious inhibitory effect on SlGSTD1 activity, especially for fenvalerate, when using CDNB as substrate. Fenvalerate and cyhalothrin can be metabolized by SlGSTD1 in E. coli and in vitro. Also, silencing of SlGSTd1 significantly increased the toxicity of fenvalerate and cyhalothrin, but had no significant effect on the mortality of larvae treated by beta-cypermethrin or chlorpyrifos. SlGSTD1 possesses peroxidase activity using cumene hydroperoxide as a stress inducer. The comprehensive results indicate that SlGSTD1 is involved in fenvalerate and cyhalothrin resistance of S. litura by detoxication and antioxidant capacity.


Assuntos
Clorpirifos , Inseticidas , Piretrinas , Animais , Antioxidantes/metabolismo , Clorpirifos/metabolismo , Escherichia coli/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Inseticidas/metabolismo , Inseticidas/farmacologia , Larva , Peroxidases/metabolismo , Piretrinas/metabolismo , Piretrinas/farmacologia , Spodoptera
15.
Front Plant Sci ; 13: 876428, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35498675

RESUMO

RNA silencing is a common antiviral mechanism in eukaryotic organisms. However, the transcriptional regulatory mechanism that controls the RNA silencing process remains elusive. Here, we performed high-depth transcriptome analysis on petunia (Petunia hybrida) leaves infected with tobacco rattle virus (TRV) strain PPK20. A total of 7,402 differentially expressed genes (DEGs) were identified. Of them, some RNA silencing-related transcripts, such as RNA-dependent RNA polymerases (RDRs), Dicer-like RNase III enzymes (DCLs), and Argonautes (AGOs), were induced by viral attack. Furthermore, we performed TRV-based virus-induced gene silencing (VIGS) assay on 39 DEGs encoding putative transcription factors (TFs), using green fluorescent protein (GFP) and phytoene desaturase (PhPDS) as reporters. Results showed that the down-regulation of PhbHLH41, PhbHLH93, PhZPT4-3, PhCOL4, PhHSF-B3A, PhNAC90, and PhWRKY75 led to enhanced TRV accumulation and inhibited PhPDS-silenced photobleaching phenotype. In contrast, silencing of PhERF22 repressed virus accumulation and promoted photobleaching development. Thus, these TFs were identified as potential positive and negative regulators of antiviral RNA silencing, respectively. One positive regulator PhCOL4, belonging to the B-box zinc finger family, was selected for further functional characterization. Silencing and transient overexpression of PhCOL4 resulted in decreased and increased expression of several RNA silencing-related genes. DNA affinity purification sequencing analysis revealed that PhCOL4 targeted PhRDR6 and PhAGO4. Dual luciferase and yeast one-hybrid assays determined the binding of PhCOL4 to the PhRDR6 and PhAGO4 promoters. Our findings suggest that TRV-GFP-PhPDS-based VIGS could be helpful to identify transcriptional regulators of antiviral RNA silencing.

16.
Sci Adv ; 8(44): eabo3315, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36322668

RESUMO

Artificial metalloenzymes (ArMs) are commonly designed with protein scaffolds containing buried coordination pockets to achieve substrate specificity and product selectivity for homogeneous reactions. However, their reactivities toward heterogeneous transformations are limited because interfacial electron transfers are hampered by the backbone shells. Here, we introduce bacterial small laccase (SLAC) as a new protein scaffold for constructing ArMs to directly catalyze electrochemical transformations. We use molecular dynamics simulation, x-ray crystallography, spectroscopy, and computation to illustrate the scaffold-directed assembly of an oxo-bridged dicobalt motif on protein surface. The resulting ArM in aqueous phase catalyzes electrochemical water oxidation without mediators or electrode modifications. Mechanistic investigation reveals the role of SLAC scaffold in defining the four-electron transfer pathway from water to oxygen. Furthermore, we demonstrate that SLAC-based ArMs implemented with Ni2+, Mn2+, Ru3+, Pd2+, or Ir3+ also enable direct bioelectrocatalysis of water electrolysis. Our study provides a versatile and generalizable route to complement heterogeneous repertoire of ArMs for expanded applications.

17.
Mitochondrial DNA B Resour ; 6(3): 846-847, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33796652

RESUMO

The genus Amphinemura belongs to the family Nemouridae (Plecoptera) and has 205 species in the Holarctic and Oriental Regions. We sequenced the fourth complete mitochondrial genome of A. bulla Shimizu, 1997. The mitogenome is 15,827 bp long with 37 genes plus a control region with an A + T content of 68.9%. There are 10 intergenic spacers (75 bp total) and 13 gene overlaps (43 bp total). All protein-coding genes (PCGs) use normal initiation codons, except ND1 and ND5 which begin with TTG and GTG. Two PCGs (COII and ND5) use a single T as a partial termination codon. Phylogenetic analyses showed that Nemoura and Amphinemura were sister group resulting in a paraphyletic Amphinemurinae different from the morphological classification.

18.
Neurol India ; 69(5): 1402-1404, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34747824

RESUMO

Wernicke's encephalopathy (WE) is an acute neuropsychiatric disorder that results from thiamine (vitamin B1) deficiency. The typical clinical manifestations, which occur as triads in 20% of patients with the disorder, are acute mental status changes, ophthalmoplegia, and ataxia. Brain magnetic resonance imaging (MRI) has important value in diagnosis as it can reveal abnormalities in the thalamus, mammillary body, third and fourth ventricles, and periaqueductal area. Here we describe a 44-year-old female patient with WE, in the context of fasting following bowel surgery. The unique neuroimaging findings were symmetrical mammillary body and dorsal midbrain abnormalities, only evident on contrast-enhanced brain MRI.


Assuntos
Encefalopatia de Wernicke , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Neuroimagem , Tiamina , Encefalopatia de Wernicke/diagnóstico por imagem
19.
Cell Death Dis ; 11(3): 175, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144238

RESUMO

Colorectal cancer (CRC) is a global healthcare problem. Radioresistance is a huge setback for CRC radiotherapy. In this text, the roles and molecular mechanisms of long non-coding RNA HOTAIR in CRC tumorigenesis and radioresistance were further investigated. ATG12 mRNA, HOTAIR, and microRNA-93 (miR-93) levels were measured by quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay. Protein levels of LC3 I, LC3 II, p62, ATG12, cleaved caspase 3, Bax, and Bcl-2 were detected by western blotting assay in cells and were examined by immunohistochemistry (IHC) assay in tissues. Cell survival fractions, viability, and apoptotic rates were determined by clonogenic survival assay, CCK-8 assay, and flow cytometry analysis, respectively. The relationships of HOTAIR, miR-93, and ATG12 were tested by bioinformatics analysis and luciferase reporter assay. Mouse xenograft tumor models were established to investigate the influence of HOTAIR knockdown on CRC radioresistance in vivo. We found that HOTAIR expression was markedly upregulated in plasma from CRC patients after radiotherapy and CRC cells after irradiation. HOTAIR knockdown, miR-93 overexpression, or ATG12 silencing weakened cell viability, induced cell apoptosis, inhibited cell autophagy, and enhanced cell radiosensitivity in CRC. HOTAIR exerted its functions by downregulating miR-93. Moreover, HOTAIR functioned as a molecular sponge of miR-93 to regulate ATG12 expression. ATG12 protein expression was markedly upregulated and associated with miR-93 and HOTAIR expression in CRC tissues. Furthermore, HOTAIR knockdown enhanced radiosensitivity of CRC xenograft tumors by regulating miR-93/ATG12 axis. In conclusion, HOTAIR knockdown potentiated radiosensitivity through regulating miR-93/ATG12 axis in CRC, further elucidating the roles and molecular basis of HOTAIR in CRC radioresistance.


Assuntos
Neoplasias Colorretais/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Autofagia/fisiologia , Proteína 12 Relacionada à Autofagia/metabolismo , Proliferação de Células/genética , Sobrevivência Celular/fisiologia , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Camundongos
20.
PLoS One ; 15(2): e0226668, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32017769

RESUMO

To accurately evaluate expression levels of target genes, stable internal reference genes is required for normalization of quantitative real-time PCR (qRT-PCR) data. However, there have been no systematical investigation on the stability of reference genes used in the bedstraw weed, Galium aparine L. (BGA). In this study, the expression profiles of seven traditionally used reference genes, namely 18S, 28S, ACT, GAPDH, EF1α, RPL7 and TBP in BGA were assessed under both biotic (developmental time and tissue), and abiotic (temperature, regions and herbicide) conditions. Four analytical algorithms (geNorm, Normfinder, BestKeeper and the ΔCt method) were used to analyze the suitability of these genes as internal reference genes. RefFinder, a comprehensive analytical software, was used to rank the overall stability of the candidate genes. The optimal normalization internal control genes were ranked as: 28S and RPL7 were best for all the different experimental conditions (developmental stages, tissues, temperature, regions and herbicide treatment); 28S and RPL7 for developmental stages; TBP and GAPDH for different tissues; 28S and GAPDH were relatively stable for different temperature; 28S and TBP were suitable for herbicide treatment. A specific set of reference genes were recommended for each experimental condition in BGA.


Assuntos
Galium/genética , Perfilação da Expressão Gênica/métodos , Reação em Cadeia da Polimerase em Tempo Real/normas , Padrões de Referência , Software
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA