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1.
Cell Mol Biol (Noisy-le-grand) ; 70(4): 191-195, 2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38678605

RESUMO

This study aimed to explore the influence of circFOXM1/miR-218-5p molecular axis in the proliferation, apoptosis and migration of glioma cells. The levels of circFOXM1 and miR-218-5p in glioma and adjacent tissues were tested by qRT-PCR. Cultured human glioma U251 cells were randomly split into groups: si-NC, si-circFOXM1, miR-NC, miR-218-5p, si-circFOXM1+anti-miR-NC, si-circFOXM1+anti-miR-218-5p. MTT method, plate clone formation, flow cytometry and Transwell experiments were utilized for detecting the proliferation, clone formation, apoptosis and migration of glioma cells. Dual-luciferase reporter experiment authenticated the targeted relation of circFOXM1 and miR-218-5p. Western blot tested the levels of E-cadherin and N-cadherin. CircFOXM1 was upregulated while miR-218-5p was low expressed in glioma tissues versus normal tissues. After circFOXM1 silence or miR-218-5p overexpression, miR-218-5p level was increased, and cell apoptosis rate and E-cadherin expression were enhancive, whereas cell proliferation, cell clone formation and migration abilities, and N-cadherin level were reduced. CircFOXM1 could affect miR-218-5 level by negative regulation. Furthermore, miR-218-5p silence could reverse the stimulative influence of si-circFOXM1 on apoptosis rate, and E-cadherin level, and the repressive effect on cell viability, cell number of colony formation and migration, and N-cadherin expression. Inhibition of circFOXM1 expression could block the proliferation, clone formation, and migration and induce apoptosis of glioma cells by upregulating miR-218-5p.


Assuntos
Apoptose , Movimento Celular , Proliferação de Células , Proteína Forkhead Box M1 , Regulação Neoplásica da Expressão Gênica , Glioma , MicroRNAs , RNA Circular , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Apoptose/genética , Movimento Celular/genética , Glioma/patologia , Glioma/genética , Glioma/metabolismo , Proliferação de Células/genética , Linhagem Celular Tumoral , RNA Circular/genética , RNA Circular/metabolismo , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Caderinas/metabolismo , Caderinas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo
2.
Front Mol Biosci ; 10: 1269478, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074089

RESUMO

Background: Allograft lung ischemia-reperfusion injury (ALIRI) is a major cause of early primary graft dysfunction and poor long-term survival after lung transplantation (LTx); however, its pathogenesis has not been fully elucidated. Cell death is a mechanism underlying ALIRI. Cuproptosis is a recently discovered form of programmed cell death. To date, no studies have been conducted on the mechanisms by which cuproptosis-related genes (CRGs) regulate ALIRI. Therefore, we explored the potential biomarkers related to cuproptosis to provide new insights into the treatment of ALIRI. Materials and methods: Datasets containing pre- and post-LTx lung biopsy samples and CRGs were obtained from the GEO database and previous studies. We identified differentially expressed CRGs (DE-CRGs) and performed functional analyses. Biomarker genes were selected using three machine learning algorithms. The ROC curve and logistic regression model (LRM) of these biomarkers were constructed. CIBERSORT was used to calculate the number of infiltrating immune cells pre- and post-LTx, and the correlation between these biomarkers and immune cells was analyzed. A competing endogenous RNA network was constructed using these biomarkers. Finally, the biomarkers were verified in a validation set and a rat LTx model using qRT-PCR and Western blotting. Results: Fifteen DE-CRGs were identified. GO analysis revealed that DE-CRGs were significantly enriched in the mitochondrial acetyl-CoA biosynthetic process from pyruvate, protein lipoylation, the tricarboxylic acid (TCA) cycle, and copper-transporting ATPase activity. KEGG enrichment analysis showed that the DE-CRGs were mainly enriched in metabolic pathways, carbon metabolism, and the TCA cycle. NFE2L2, NLRP3, LIPT1, and MTF1 were identified as potential biomarker genes. The AUC of the ROC curve for each biomarker was greater than 0.8, and the LRM provided an excellent classifier with an AUC of 0.96. These biomarkers were validated in another dataset and a rat LTx model, which exhibited good performance. In the CIBERSORT analysis, differentially expressed immune cells were identified, and the biomarkers were associated with the immune cells. Conclusion: NFE2L2, NLRP3, LIPT1, and MTF1 may serve as predictors of cuproptosis and play an important role in the pathogenesis of cuproptosis in ALIRI.

3.
Nano Lett ; 23(24): 11485-11492, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38063397

RESUMO

The spin Hall effect (SHE) can generate a pure spin current by an electric current, which is promisingly used to electrically control magnetization. To reduce the power consumption of this control, a giant spin Hall angle (SHA) in the SHE is desired in low-resistivity systems for practical applications. Here, critical spin fluctuation near the antiferromagnetic (AFM) phase transition in chromium (Cr) is proven to be an effective mechanism for creating an additional part of the SHE, named the fluctuation spin Hall effect. The SHA is significantly enhanced when the temperature approaches the Néel temperature (TN) of Cr and has a peak value of -0.36 near TN. This value is higher than the room-temperature value by 153% and leads to a low normalized power consumption among known spin-orbit torque materials. This study demonstrates the critical spin fluctuation as a prospective way to increase the SHA and enriches the AFM material candidates for spin-orbitronic devices.

4.
Proc Natl Acad Sci U S A ; 120(14): e2300439120, 2023 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-36996102

RESUMO

Ongoing host-pathogen interactions can trigger a coevolutionary arms race, while genetic diversity within the host can facilitate its adaptation to pathogens. Here, we used the diamondback moth (Plutella xylostella) and its pathogen Bacillus thuringiensis (Bt) as a model for exploring an adaptive evolutionary mechanism. We found that insect host adaptation to the primary Bt virulence factors was tightly associated with a short interspersed nuclear element (SINE - named SE2) insertion into the promoter of the transcriptionally activated MAP4K4 gene. This retrotransposon insertion coopts and potentiates the effect of the transcription factor forkhead box O (FOXO) in inducing a hormone-modulated Mitogen-activated protein kinase (MAPK) signaling cascade, leading to an enhancement of a host defense mechanism against the pathogen. This work demonstrates that reconstructing a cis-trans interaction can escalate a host response mechanism into a more stringent resistance phenotype to resist pathogen infection, providing a new insight into the coevolutionary mechanism of host organisms and their microbial pathogens.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Endotoxinas/farmacologia , Retroelementos/genética , Mariposas/metabolismo , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis/metabolismo , Resistência a Inseticidas/genética , Larva/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas Hemolisinas/metabolismo
5.
Nat Commun ; 13(1): 6024, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224245

RESUMO

Maintaining fitness during pathogen infection is vital for host survival as an excessive response can be as detrimental as the infection itself. Fitness costs are frequently associated with insect hosts countering the toxic effect of the entomopathogenic bacterium Bacillus thuringiensis (Bt), which delay the evolution of resistance to this pathogen. The insect pest Plutella xylostella has evolved a mechanism to resist Bt toxins without incurring significant fitness costs. Here, we reveal that non-phosphorylated and phosphorylated forms of a MAPK-modulated transcription factor fushi tarazu factor 1 (FTZ-F1) can respectively orchestrate down-regulation of Bt Cry1Ac toxin receptors and up-regulation of non-receptor paralogs via two distinct binding sites, thereby presenting Bt toxin resistance without growth penalty. Our findings reveal how host organisms can co-opt a master molecular switch to overcome pathogen invasion with low cost, and contribute to understanding the underlying mechanism of growth-defense tradeoffs during host-pathogen interactions in P. xylostella.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Medicamentos de Ervas Chinesas , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Insetos/metabolismo , Resistência a Inseticidas/genética , Larva/metabolismo , Fatores de Transcrição/metabolismo
6.
Pestic Biochem Physiol ; 182: 105053, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35249643

RESUMO

Deciphering the molecular mechanisms of insect resistance to Bacillus thuringiensis (Bt) based biotechnology products including Bt sprays and Bt crops is critical for the long-term application of Bt technology. Previously, we established that down-regulation of the ABC transporter gene PxABCG1, trans-regulated by the MAPK signaling pathway, contributed to high-level resistance to Bt Cry1Ac toxin in diamondback moth, Plutella xylostella (L.). However, the underlying transcriptional regulatory mechanism was unknown. Herein, we identified putative binding sites (PBSs) of the transcription factor (TF) POUM1 in the PxABCG1 promoter and used a dual-luciferase reporter assay (DLRA) and yeast one-hybrid (Y1H) assay to reveal that POUM1 activates PxABCG1 via interaction with one of these sites. The expression of POUM1 was significantly decreased in the midgut tissue of Cry1Ac-resistant P. xylostella strains compared to a Cry1Ac-susceptible P. xylostella strain. Silencing of POUM1 expression resulted in reduced expression of the PxABCG1 gene and an increase in larval tolerance to Bt Cry1Ac toxin in the Cry1Ac-susceptible P. xylostella strain. Furthermore, silencing of PxMAP4K4 expression increased the expression of both POUM1 and PxABCG1 genes in the Cry1Ac-resistant P. xylostella strain. These results indicate that the POUM1 induces PxABCG1 expression, while the activated MAPK cascade represses PxABCG1 expression thus reducing Cry1Ac susceptibility in P. xylostella. This result deepens our understanding of the transcriptional regulatory mechanism of midgut Cry receptor genes and the molecular basis of the evolution of Bt resistance in insects.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/farmacologia , Endotoxinas/metabolismo , Endotoxinas/farmacologia , Proteínas Hemolisinas/metabolismo , Proteínas Hemolisinas/farmacologia , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Larva/genética , Larva/metabolismo , Mariposas/genética , Mariposas/metabolismo , Fatores de Transcrição/genética
7.
PLoS Genet ; 18(2): e1010037, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35113858

RESUMO

The benefits of biopesticides and transgenic crops based on the insecticidal Cry-toxins from Bacillus thuringiensis (Bt) are considerably threatened by insect resistance evolution, thus, deciphering the molecular mechanisms underlying insect resistance to Bt products is of great significance to their sustainable utilization. Previously, we have demonstrated that the down-regulation of PxmALP in a strain of Plutella xylostella (L.) highly resistant to the Bt Cry1Ac toxin was due to a hormone-activated MAPK signaling pathway and contributed to the resistance phenotype. However, the underlying transcriptional regulatory mechanism remains enigmatic. Here, we report that the PxGATAd transcription factor (TF) is responsible for the differential expression of PxmALP observed between the Cry1Ac susceptible and resistant strains. We identified that PxGATAd directly activates PxmALP expression via interacting with a non-canonical but specific GATA-like cis-response element (CRE) located in the PxmALP promoter region. A six-nucleotide insertion mutation in this cis-acting element of the PxmALP promoter from the resistant strain resulted in repression of transcriptional activity, affecting the regulatory performance of PxGATAd. Furthermore, silencing of PxGATAd in susceptible larvae reduced the expression of PxmALP and susceptibility to Cry1Ac toxin. Suppressing PxMAP4K4 expression in the resistant larvae transiently recovered both the expression of PxGATAd and PxmALP, indicating that the PxGATAd is a positive responsive factor involved in the activation of PxmALP promoter and negatively regulated by the MAPK signaling pathway. Overall, this study deciphers an intricate regulatory mechanism of PxmALP gene expression and highlights the concurrent involvement of both trans-regulatory factors and cis-acting elements in Cry1Ac resistance development in lepidopteran insects.


Assuntos
Toxinas de Bacillus thuringiensis/metabolismo , Endotoxinas/metabolismo , Proteínas Hemolisinas/metabolismo , Resistência a Inseticidas/genética , Sistema de Sinalização das MAP Quinases/fisiologia , Animais , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Toxinas de Bacillus thuringiensis/farmacologia , Proteínas de Bactérias/genética , Endotoxinas/farmacologia , Granulovirus/genética , Proteínas Hemolisinas/farmacologia , Proteínas de Insetos/genética , Inseticidas/metabolismo , Larva/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mariposas/genética , Mariposas/metabolismo , Fatores de Transcrição/genética
8.
Int J Mol Sci ; 22(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198929

RESUMO

The molecular mechanisms of insect resistance to Cry toxins generated from the bacterium Bacillus thuringiensis (Bt) urgently need to be elucidated to enable the improvement and sustainability of Bt-based products. Although downregulation of the expression of midgut receptor genes is a pivotal mechanism of insect resistance to Bt Cry toxins, the underlying transcriptional regulation of these genes remains elusive. Herein, we unraveled the regulatory mechanism of the downregulation of the ABC transporter gene PxABCG1 (also called Pxwhite), a functional midgut receptor of the Bt Cry1Ac toxin in Plutella xylostella. The PxABCG1 promoters of Cry1Ac-susceptible and Cry1Ac-resistant strains were cloned and analyzed, and they showed clear differences in activity. Subsequently, a dual-luciferase reporter assay, a yeast one-hybrid (Y1H) assay, and RNA interference (RNAi) experiments demonstrated that a cis-mutation in a binding site of the Hox transcription factor Antennapedia (Antp) decreased the promoter activity of the resistant strain and eliminated the binding and regulation of Antp, thereby enhancing the resistance of P. xylostella to the Cry1Ac toxin. These results advance our knowledge of the roles of cis- and trans-regulatory variations in the regulation of midgut Cry receptor genes and the evolution of Bt resistance, contributing to a more complete understanding of the Bt resistance mechanism.


Assuntos
Membro 1 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Toxinas de Bacillus thuringiensis/genética , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Receptores de Superfície Celular/genética , Animais , Bacillus thuringiensis/genética , Endotoxinas/genética , Lepidópteros/efeitos dos fármacos , Lepidópteros/genética , Mutação/genética , Regiões Promotoras Genéticas/genética
9.
Appl Environ Microbiol ; 87(13): e0046621, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-33893113

RESUMO

Deciphering the molecular mechanisms underlying insect resistance to Cry toxins produced by Bacillus thuringiensis (Bt) is pivotal for the sustainable utilization of Bt biopesticides and transgenic Bt crops. Previously, we identified that mitogen-activated protein kinase (MAPK)-mediated reduced expression of the PxABCB1 gene is associated with Bt Cry1Ac resistance in the diamondback moth, Plutella xylostella (L.). However, the underlying transcriptional regulation mechanism remains enigmatic. Here, the PxABCB1 promoter in Cry1Ac-susceptible and Cry1Ac-resistant P. xylostella strains was cloned and analyzed and found to contain a putative Jun binding site (JBS). A dual-luciferase reporter assay and yeast one-hybrid assay demonstrated that the transcription factor PxJun repressed PxABCB1 expression by interacting with this JBS. The expression levels of PxJun were increased in the midguts of all resistant strains compared to the susceptible strain. Silencing of PxJun expression significantly elevated PxABCB1 expression and Cry1Ac susceptibility in the resistant NIL-R strain, and silencing of PxMAP4K4 expression decreased PxJun expression and also increased PxABCB1 expression. These results indicate that MAPK-activated PxJun suppresses PxABCB1 expression to confer Cry1Ac resistance in P. xylostella, deepening our understanding of the transcriptional regulation of midgut Cry receptor genes and the molecular basis of insect resistance to Bt Cry toxins. IMPORTANCE The transcriptional regulation mechanisms underlying reduced expression of Bt toxin receptor genes in Bt-resistant insects remain elusive. This study unveils that a transcription factor PxJun activated by the MAPK signaling pathway represses PxABCB1 expression and confers Cry1Ac resistance in P. xylostella. Our results provide new insights into the transcriptional regulation mechanisms of midgut Cry receptor genes and deepen our understanding of the molecular basis of insect resistance to Bt Cry toxins. To our knowledge, this study identified the first transcription factor that can be involved in the transcriptional regulation mechanisms of midgut Cry receptor genes in Bt-resistant insects.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Toxinas de Bacillus thuringiensis/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Mariposas , Proteínas Proto-Oncogênicas c-jun/genética , Animais , Larva/genética , Larva/metabolismo , Mariposas/genética , Mariposas/metabolismo
10.
Nat Commun ; 11(1): 3003, 2020 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-32532972

RESUMO

The arms race between entomopathogenic bacteria and their insect hosts is an excellent model for decoding the intricate coevolutionary processes of host-pathogen interaction. Here, we demonstrate that the MAPK signaling pathway is a general switch to trans-regulate differential expression of aminopeptidase N and other midgut genes in an insect host, diamondback moth (Plutella xylostella), thereby countering the virulence effect of Bacillus thuringiensis (Bt) toxins. Moreover, the MAPK cascade is activated and fine-tuned by the crosstalk between two major insect hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH) to elicit an important physiological response (i.e. Bt resistance) without incurring the significant fitness costs often associated with pathogen resistance. Hormones are well known to orchestrate physiological trade-offs in a wide variety of organisms, and our work decodes a hitherto undescribed function of these classic hormones and suggests that hormonal signaling plasticity is a general cross-kingdom strategy to fend off pathogens.


Assuntos
Bacillus thuringiensis/metabolismo , Toxinas Bacterianas/metabolismo , Hormônios de Inseto/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mariposas/metabolismo , Transdução de Sinais , Animais , Bacillus thuringiensis/fisiologia , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/metabolismo , Antígenos CD13/classificação , Antígenos CD13/genética , Antígenos CD13/metabolismo , Endotoxinas/metabolismo , Regulação da Expressão Gênica , Proteínas Hemolisinas/metabolismo , Interações Hospedeiro-Patógeno , Proteínas de Insetos/classificação , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Resistência a Inseticidas/genética , Mariposas/genética , Mariposas/microbiologia , Filogenia , Células Sf9 , Spodoptera
11.
Pestic Biochem Physiol ; 163: 23-30, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31973862

RESUMO

Insecticidal Cry toxins produced by Bacillus thuringiensis (Bt) have been widely used to control agricultural pests in both foliage sprays and transgenic crops. Nevertheless, rapid evolution of insect resistance to Cry toxins requires elucidation of the molecular mechanisms involved in Cry resistance. Two proposed models have been described to explain the toxicity of Cry proteins, the classic model states that Cry protoxin is activated by midgut proteases resulting in activated toxin that binds to receptors and forms a pore in the midgut cells triggering larval death, and the newly proposed dual model of the mode of action of Bt Cry toxins states that protoxin and activated toxins may have different mechanisms of action since several resistant strains to activated Cry toxins are still susceptible to the same Cry-protoxin. Protoxin activation by midgut proteases is a key step in both models. Herein, we evaluated Cry1Ac protoxin activation in a susceptible Plutella xylostella (L.) strain (DBM1Ac-S) and in the near-isogenic strain (NIL-R) with high field-evolved Cry1Ac resistance. Previous work showed that Cry1Ac resistance in NIL-R correlates with reduced binding to midgut receptors due to enhanced MAPK signaling pathway and down regulation of ABCC2 receptor. However, reduced midgut trypsin levels and altered midgut protease gene transcription were also observed in the Cry1Ac-resistant field isolated strain that is parent of the NIL-R strain. Therefore, we analyzed the midgut protease activities in both DBM1Ac-S and NIL-R strains. Detection of enzymatic activities showed that caseinolytic protease, trypsin and chymotrypsin activities were not significantly different between the susceptible and resistant strains. Furthermore, treatment with different trypsin or chymotrypsin inhibitors, such as Nα-tosyl-l-lysine chloromethyl ketone (TLCK) or Np-tosyl-L-phenylalanine chloromethyl ketone (TPCK) did not affect the susceptibility to Cry1Ac protoxin of the DBM1Ac-S and NIL-R larvae. Bioassay results indicated that the NIL-R larvae showed similar resistant levels to both Cry1Ac protoxin and trypsin-activated toxin. Taken together, our results demonstrated that high-level field-evolved Cry1Ac resistance in the NIL-R strain is independent of Cry1Ac protoxin activation and the specific protoxin mechanism of action. This discovery will strengthen our comprehensive understanding of the complex mechanistic basis of Bt resistance in different insects.


Assuntos
Bacillus thuringiensis , Mariposas , Animais , Proteínas de Bactérias , Endotoxinas , Proteínas Hemolisinas , Proteínas de Insetos , Resistência a Inseticidas , Larva , Peptídeo Hidrolases
12.
Toxins (Basel) ; 12(2)2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31979385

RESUMO

Bacillus thuringiensis (Bt) produce diverse insecticidal proteins to kill insect pests. Nevertheless, evolution of resistance to Bt toxins hampers the sustainable use of this technology. Previously, we identified down-regulation of a trypsin-like serine protease gene PxTryp_SPc1 in the midgut transcriptome and RNA-Seq data of a laboratory-selected Cry1Ac-resistant Plutella xylostella strain, SZ-R. We show here that reduced PxTryp_SPc1 expression significantly reduced caseinolytic and trypsin protease activities affecting Cry1Ac protoxin activation, thereby conferring higher resistance to Cry1Ac protoxin than activated toxin in SZ-R strain. Herein, the full-length cDNA sequence of PxTryp_SPc1 gene was cloned, and we found that it was mainly expressed in midgut tissue in all larval instars. Subsequently, we confirmed that the PxTryp_SPc1 gene was significantly decreased in SZ-R larval midgut and was further reduced when selected with high dose of Cry1Ac protoxin. Moreover, down-regulation of the PxTryp_SPc1 gene was genetically linked to resistance to Cry1Ac in the SZ-R strain. Finally, RNAi-mediated silencing of PxTryp_SPc1 gene expression decreased larval susceptibility to Cry1Ac protoxin in the susceptible DBM1Ac-S strain, supporting that low expression of PxTryp_SPc1 gene is involved in Cry1Ac resistance in P. xylostella. These findings contribute to understanding the role of midgut proteases in the mechanisms underlying insect resistance to Bt toxins.


Assuntos
Toxinas de Bacillus thuringiensis/toxicidade , Endotoxinas/toxicidade , Proteínas Hemolisinas/toxicidade , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Inseticidas/toxicidade , Mariposas/genética , Tripsina/genética , Animais , Quimotripsina/metabolismo , Feminino , Trato Gastrointestinal , Larva/efeitos dos fármacos , Larva/genética , Masculino , Mariposas/efeitos dos fármacos , Controle Biológico de Vetores , Filogenia , Tripsina/metabolismo
13.
Pest Manag Sci ; 76(2): 712-720, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31359575

RESUMO

BACKGROUND: Rapid evolution of pest resistance has seriously threatened the sustainable use of Bacillus thuringiensis (Bt). The diamondback moth, Plutella xylostella (L.), is the first pest to develop resistance to Bt biopesticides in the open field, which renders it an excellent model to explore the molecular basis of Bt resistance in insects. Our previous midgut transcriptome and RNA-Seq profiles showed that the P-glycoprotein gene PxABCB1 was down-regulated in two Cry1Ac-resistant P. xylostella strains, suggesting its potential involvement in Cry1Ac resistance in P. xylostella. RESULTS: In this study, the bona fide full-length cDNA sequence of the PxABCB1 gene was cloned and analyzed, and the expression of the PxABCB1 gene was detected in all tissues and developmental stages, with the highest expression in midgut tissue and the female adult stage. Although no consistent non-synonymous mutations were identified between the susceptible and resistant strains, PxABCB1 gene expression was remarkably decreased in all resistant strains, and the association was further validated by Cry1Ac selection in the moderately resistant SZ-R strain. Moreover, knockdown of the PxABCB1 gene expression resulted in significantly reduced larval susceptibility to Cry1Ac toxin in the DBM1Ac-S strain, and decreased expression of the PxABCB1 gene was tightly linked to Cry1Ac resistance in P. xylostella. CONCLUSION: Our results demonstrated that down-regulation of the PxABCB1 gene is associated with both laboratory-selected and field-evolved Cry1Ac resistance in P. xylostella. This knowledge will be conducive to further elucidating the complicated molecular basis of Bt resistance and developing new insect resistance management tactics. © 2019 Society of Chemical Industry.


Assuntos
Bacillus thuringiensis , Mariposas , Subfamília B de Transportador de Cassetes de Ligação de ATP , Animais , Proteínas de Bactérias , Endotoxinas , Feminino , Proteínas Hemolisinas , Resistência a Inseticidas , Larva
14.
Insect Biochem Mol Biol ; 107: 31-38, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30710623

RESUMO

Rapid evolution of resistance by insect pests severely jeopardizes the sustainable utilization of biopesticides and transgenic crops that produce insecticidal crystal proteins derived from the entomopathogenic bacterium Bacillus thuringiensis (Bt). Recently, high levels of resistance to Bt Cry1 toxins have been reported to be genetically linked to the mutation or down-regulation of ABC transporter subfamily C genes ABCC2 and ABCC3 in seven lepidopteran insects, including Plutella xylostella (L.). To further determine the causal relationship between alterations in the PxABCC2 and PxABCC3 genes and Cry1Ac resistance in P. xylostella, the novel CRISPR/Cas9 genome engineering system was utilized to successfully construct two knockout strains: the ABCC2KO strain is homozygous for a 4-bp deletion in exon 3 of the PxABCC2 gene, and the ABCC3KO strain is homozygous for a 5-bp deletion in exon 3 of the PxABCC3 gene, both of which can produce only truncated ABCC proteins. Bioassay results indicated that high levels of resistance to the Cry1Ac protoxin were observed in both the ABCC2KO (724-fold) and ABCC3KO (413-fold) strains compared to the original susceptible DBM1Ac-S strain. Subsequently, dominance degree and genetic complementation tests demonstrated that Cry1Ac resistance in both the knockout strains was incompletely recessive, and Cry1Ac resistance alleles were located in the classic BtR-1 resistance locus that harbored the PxABCC2 and PxABCC3 genes, similar to the near-isogenic resistant NIL-R strain. Moreover, qualitative toxin binding assays revealed that the binding of the Cry1Ac toxin to midgut brush border membrane vesicles (BBMVs) in both knockout strains was dramatically reduced compared to that in the susceptible DBM1Ac-S strain. In summary, our CRISPR/Cas9-mediated genome editing study presents, for the first time, in vivo reverse genetics evidence for both the ABCC2 and ABCC3 proteins as midgut functional receptors for Bt Cry1 toxins in insects, which provides new insight into the pivotal roles of both the ABCC2 and ABCC3 proteins in the complex molecular mechanism of insect resistance to Bt Cry1 toxins.


Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mariposas/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Animais , Bacillus thuringiensis/química , Toxinas de Bacillus thuringiensis , Sequência de Bases , Sistemas CRISPR-Cas , Técnicas de Inativação de Genes , Proteínas de Insetos/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Larva/crescimento & desenvolvimento , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo
15.
Int J Mol Sci ; 19(11)2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30469390

RESUMO

Transcription factors (TFs) play essential roles in the transcriptional regulation of functional genes, and are involved in diverse physiological processes in living organisms. The fruit fly Drosophila melanogaster, a simple and easily manipulated organismal model, has been extensively applied to study the biological functions of TFs and their related transcriptional regulation mechanisms. It is noteworthy that with the development of genetic tools such as CRISPR/Cas9 and the next-generation genome sequencing techniques in recent years, identification and dissection the complex genetic regulatory networks of TFs have also made great progress in other insects beyond Drosophila. However, unfortunately, there is no comprehensive review that systematically summarizes the structures and biological functions of TFs in both model and non-model insects. Here, we spend extensive effort in collecting vast related studies, and attempt to provide an impartial overview of the progress of the structure and biological functions of current documented TFs in insects, as well as the classical and emerging research methods for studying their regulatory functions. Consequently, considering the importance of versatile TFs in orchestrating diverse insect physiological processes, this review will assist a growing number of entomologists to interrogate this understudied field, and to propel the progress of their contributions to pest control and even human health.


Assuntos
Proteínas de Drosophila/genética , Drosophila/genética , Fatores de Transcrição/genética , Animais , Drosophila/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Evolução Molecular , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Ativação Transcricional
16.
Insect Sci ; 25(6): 959-968, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28497882

RESUMO

The expression level of cytochrome P450 genes in insects can be induced by plant allelochemicals, which is important for insects to adapt to host plants. Cytochrome P450 CYP6B7 has been reported to be involved in pyrethroid insecticide resistance in Helicoverpa armigera, and its transcription level was induced by some inducers. Currently, the regulatory mechanism of the induced expression of CYP6B7 remains unknown, although it is very important for understanding the detoxification mechanism to allelochemicals in host plants. The objective of the present study was to investigate the cis-acting element in the promoter of CYP6B7 mediating the inducible up-regulation of CYP6B7 in H. armigera by 2-tridecanone. The promoter region of CYP6B7 was cloned by genome walking technique and analyzed by transient transfection assay. Progressive 5' deletion of the promoter region of CYP6B7 revealed that the relative luciferase activity of construct -320/+232 could be significantly induced by 2-tridecanone. Further stepwise deletion between -320 and -238 bp found that construct -292/+232 could also be significantly induced by 2-tridecanone, but the adjacent construct -256/+232 could not, suggesting the essential role of the sequence between -292 and -257 bp for 2-tridecanone induction. Nucleotide mutations between -292 and -281 bp had no influence on the induction effect by 2-tridecanone, but nucleotide mutations between -280 and -257 bp significantly decreased the induction effect. These results demonstrated that the cis-acting element for 2-tridecanone induction was between -280 and -257 bp in the promoter of CYP6B7.


Assuntos
Família 6 do Citocromo P450/genética , Cetonas/farmacologia , Lepidópteros/enzimologia , Lepidópteros/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Adaptação Fisiológica/efeitos dos fármacos , Animais , Clonagem Molecular , Lepidópteros/efeitos dos fármacos , Lepidópteros/fisiologia , Mutação , Regiões Promotoras Genéticas/genética , Transcrição Gênica/efeitos dos fármacos
17.
Pestic Biochem Physiol ; 132: 53-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27521913

RESUMO

Pyrethroid resistance was one of the main reasons for control failure of cotton bollworm Helicoverpa armigera (Hübner) in China. The promotion of Bt crops decreased the application of chemical insecticides in controlling H.armigera. However, the cotton bollworm still kept high levels of resistance to fenvalerate. In this study, the resistance levels of 8 field-collected strains of H. armigera from north of China to 4 insecticides, as well as the expression levels of related P450 genes were investigated. The results of bioassay indicated that the resistance levels to fenvalerate in the field strains varied from 5.4- to 114.7-fold, while the resistance levels to lambda-cyhalothrin, phoxim and methomyl were low, which were ranged from 1.5- to 5.2-, 0.2- to 1.6-, and 2.9- to 8.3- fold, respectively, compared to a susceptible strain. Synergistic experiment showed that PBO was the most effective synergist in increasing the sensitivity of H. armigera to fenvalerate, suggesting that P450 enzymes were involved in the pyrethroid resistance in the field strains. The results of quantitative RT-PCR indicated that eight P450 genes (CYP332A1, CYP4L11, CYP4L5, CYP4M6, CYP4M7, CYP6B7, CYP9A12, CYP9A14) were all significantly overexpressed in Hejian1 and Xiajin1 strains of H. armigera collected in 2013, and CYP4L5 was significantly overexpressed in all the 6 field strains collected in 2014. CYP332A1, CYP6B7 and CYP9A12 had very high overexpression levels in all the field strains, indicating their important roles in fenvalerate resistance. The results suggested that multiple P450 genes were involved in the high-level fenvalerate-resistance in different field strains of H. armigera collected from north of China.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Resistência a Inseticidas , Inseticidas , Mariposas/genética , Nitrilas , Piretrinas , Animais , China , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação da Expressão Gênica , Resistência a Inseticidas/genética , Mariposas/efeitos dos fármacos
18.
Int J Clin Exp Med ; 8(9): 16077-82, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26629115

RESUMO

The aim of this study was to investigate the clinical application effects of a novel computer-aided detection (CAD) system based on three-dimensional computed tomography (CT) images on pulmonary nodule. 98 cases with pulmonary nodule (PN) in our hospital from Jun, 2009 to Jun, 2013 were analysed in this study. All cases underwent PN detection both by the simple spiral CT scan and by the computer-aided system based on 3D CT images, respectively. Postoperative pathological results were considered as the "gold standard", for both two checking methods, the diagnostic accuracies for determining benign and malignant PN were calculated. Under simple spiral CT scan method, 63 cases is malignant, including 50 true positive cases and 13 false positive cases from the "gold standard"; 35 cases is benign, 16 true negative case and 19 false negative cases, the Sensitivity 1 (Se1)=0.725, Specificity1 (Sp1)=0.448, Agreement rate1 (Kappa 1)=0.673, J1 (Youden's index 1)=0.173, LR(+)1=1.616, LR(-)1=0.499. Kappa 1=0.673 between the 0.4 and 0.75, has a moderate consistency. Underwent computer-aided detection (CAD) based on 3D CT method, 67cases is malignant, including 62 true positive cases and 7 false positive cases; 31 cases is benign, 24 true negative case and 7 false negative cases, Sensitivity 2 (Se2)=0.899, Specificity2 (Sp2)=0.828, Agreement rate (Kappa 2)=0.877, J2 (Youden's index 2)=0.727, LR(+)2=5.212, LR(-)2=0.123. Kappa 2=0.877 >0.75, has a good consistency. Computer-aided PN detecting system based on 3D CT images has better clinical application value, and can help doctor carry out early diagnosis of lung disease (such as cancer, etc.) through CT images.

19.
Plant Cell Rep ; 33(4): 617-31, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24682459

RESUMO

KEY MESSAGE: A high-quality rice activation tagging population has been developed and screened for drought-tolerant lines using various water stress assays. One drought-tolerant line activated two rice glutamate receptor-like genes. Transgenic overexpression of the rice glutamate receptor-like genes conferred drought tolerance to rice and Arabidopsis. Rice (Oryza sativa) is a multi-billion dollar crop grown in more than one hundred countries, as well as a useful functional genetic tool for trait discovery. We have developed a population of more than 200,000 activation-tagged rice lines for use in forward genetic screens to identify genes that improve drought tolerance and other traits that improve yield and agronomic productivity. The population has an expected coverage of more than 90 % of rice genes. About 80 % of the lines have a single T-DNA insertion locus and this molecular feature simplifies gene identification. One of the lines identified in our screens, AH01486, exhibits improved drought tolerance. The AH01486 T-DNA locus is located in a region with two glutamate receptor-like genes. Constitutive overexpression of either glutamate receptor-like gene significantly enhances the drought tolerance of rice and Arabidopsis, thus revealing a novel function of this important gene family in plant biology.


Assuntos
Adaptação Fisiológica/genética , DNA Bacteriano/genética , Secas , Genes de Plantas/genética , Mutagênese Insercional/métodos , Oryza/genética , Receptores de Glutamato/genética , Arabidopsis/genética , Arabidopsis/fisiologia , Cruzamentos Genéticos , Regulação da Expressão Gênica de Plantas , Loci Gênicos , Genoma de Planta/genética , Mutagênese Insercional/genética , Oryza/fisiologia , Fenótipo , Transgenes/genética
20.
J Pers Disord ; 26(3): 393-401, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22686227

RESUMO

The objective of this study was to investigate the frequency, clinical characteristics, and comorbidity of borderline personality disorder (BPD) among psychiatric outpatients in two clinics at Shanghai Mental Health Center. A cross-sectional investigation was conducted. From 3,075 outpatients screened using the Personality Diagnostic Questionnaire-IV+, 2,284 patients positive for a personality disorder were assessed using the Structured Clinical Interview for DSM-IV Personality Disorders. The frequency of BPD among the psychiatric outpatients was 5.8%, with a frequency of 3.5% among males and 7.5% among females (p < .01). BPD was found to have extensive comorbidity with Axis I and II disorders. This study proves that BPD does occur in China. The detected frequency among outpatients is lower than that reported in North America.


Assuntos
Transtorno da Personalidade Borderline/diagnóstico , Transtorno da Personalidade Borderline/epidemiologia , Pacientes Ambulatoriais/estatística & dados numéricos , Adolescente , Adulto , China/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Determinação da Personalidade , Prevalência , Fatores Sexuais , Inquéritos e Questionários
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