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1.
BMC Pediatr ; 24(1): 320, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38724982

RESUMO

BACKGROUND: Alcohol consumption by children and adolescents is receiving increasing attention. It may cause dyslipidemia, a risk factor for cardiovascular disease. However, the association between alcohol consumption and blood lipids in children and adolescents is unclear, and so we aimed to characterize this association. METHODS: Data from the China Health and Nutrition Survey were extracted from children and adolescents aged 7-18 years for whom information was available on alcohol consumption. The population was divided into drinking and nondrinking groups. The χ2, Student's t, or Mann-Whitney U test was used to compare groups. Univariate and multivariate linear regression and propensity score matching (PSM) analysis were used to identify the association between alcohol consumption and blood lipids. RESULTS: This study included 408 children and adolescents with 35 drinkers and 373 nondrinkers. The drinkers had significantly lower values of total cholesterol (TC) (3.8 mmol/L for nondrinkers versus 3.5 mmol/L for drinkers, p = 0.002) and high-density lipoprotein cholesterol (HDL-C) (1.3 mmol/L for nondrinkers versus 1.2 mmol/L for drinkers, p = 0.007), but not for low-density lipoprotein cholesterol (LDL-C) (2.1 mmol/L for nondrinkers versus 2.0 mmol/L for drinkers, p = 0.092) or triglyceride (TG) (0.9 mmol/L for nondrinkers versus 0.8 mmol/L for drinkers, p = 0.21). The univariate and multivariate analyses led to the same conclusions. After PSM there was still a significant negative association between alcohol consumption and TC or HDL-C. CONCLUSION: Alcohol consumption in children and adolescents exhibited significant negative associated with TC and HDL-C, but not with LDL-C or TG. These findings need to be confirmed in future prospective research, and the health effects of blood lipid changes caused by drinking in children and adolescents need to be clarified.


Assuntos
Consumo de Bebidas Alcoólicas , Inquéritos Nutricionais , Adolescente , Criança , Feminino , Humanos , Masculino , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/efeitos adversos , China/epidemiologia , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Estudos Transversais , Dislipidemias/sangue , Dislipidemias/epidemiologia , Dislipidemias/etiologia , População do Leste Asiático , Lipídeos/sangue , Fatores de Risco , Triglicerídeos/sangue
2.
Appl Microbiol Biotechnol ; 106(8): 3103-3112, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35389068

RESUMO

Daptomycin is a new lipopeptide antibiotic for treatment of severe infection caused by multi-drug-resistant bacteria, but its production cost remains high currently. Thus, it is very important to improve the fermentation ability of the daptomycin producer Streptomyces roseosporus. Here, we found that the deletion of proteasome in S. roseosporus would result in the loss of ability to produce daptomycin. Therefore, transcriptome and 4D label-free proteome analyses of the proteasome mutant (Δprc) and wild type were carried out, showing 457 differential genes. Further, five genes were screened by integrated crotonylation omics analysis. Among them, two genes (orf04750/orf05959) could significantly promote the daptomycin synthesis by overexpression, and the fermentation yield in shake flask increased by 54% and 76.7%, respectively. By enhancing the crotonylation modification via lysine site mutation (K-Q), the daptomycin production in shake flask was finally increased by 98.8% and 206.3%, respectively. This result proved that the crotonylation modification of appropriate proteins could effectively modulate daptomycin biosynthesis. In summary, we established a novel strategy of gene screen for antibiotic biosynthesis process, which is more convenient than the previous screening method based on pathway-specific regulators. KEY POINTS: • Δprc strain has lost the ability of daptomycin production • Five genes were screened by multi-omics analysis • Two genes (orf04750/orf05959) could promote the daptomycin synthesis by overexpression.


Assuntos
Daptomicina , Streptomyces , Antibacterianos/farmacologia , Complexo de Endopeptidases do Proteassoma , Proteoma/metabolismo , Streptomyces/metabolismo
3.
Metab Eng ; 67: 198-215, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34166765

RESUMO

Actinomycetes are recognized as excellent producers of microbial natural products, which have a wide range of applications, especially in medicine, agriculture and stockbreeding. The three main indexes of industrialization (titer, purity and stability) must be taken into overall consideration in the manufacturing process of natural products. Over the past decades, synthetic biology techniques have expedited the development of industrially competitive strains with excellent performances. Here, we summarize various rational engineering strategies for upgrading the performance of industrial actinomycetes, which include enhancing the yield of natural products, eliminating the by-products and improving the genetic stability of engineered strains. Furthermore, the current challenges and future perspectives for optimizing the industrial strains more systematically through combinatorial engineering strategies are also discussed.


Assuntos
Actinobacteria , Produtos Biológicos , Actinobacteria/genética , Actinomyces , Engenharia Metabólica , Biologia Sintética
4.
Microb Cell Fact ; 19(1): 99, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32375781

RESUMO

BACKGROUND: Large-scale genome reduction has been performed to significantly improve the performance of microbial chassis. Identification of the essential or dispensable genes is pivotal for genome reduction to avoid synthetic lethality. Here, taking Streptomyces as an example, we developed a combinatorial strategy for systematic identification of large and dispensable genomic regions in Streptomyces based on multi-omics approaches. RESULTS: Phylogenetic tree analysis revealed that the model strains including S. coelicolor A3(2), S. albus J1074 and S. avermitilis MA-4680 were preferred reference for comparative analysis of candidate genomes. Multiple genome alignment suggested that the Streptomyces genomes embodied highly conserved core region and variable sub-telomeric regions, and may present symmetric or asymmetric structure. Pan-genome and functional genome analyses showed that most conserved genes responsible for the fundamental functions of cell viability were concentrated in the core region and the vast majority of abundant genes were dispersed in the sub-telomeric regions. These results suggested that large-scale deletion can be performed in sub-telomeric regions to greatly streamline the Streptomyces genomes for developing versatile chassis. CONCLUSIONS: The integrative approach of comparative genomics, functional genomics and pan-genomics can not only be applied to perform a multi-tiered dissection for Streptomyces genomes, but also work as a universal method for systematic analysis of removable regions in other microbial hosts in order to generate more miscellaneous and versatile chassis with minimized genome for drug discovery.


Assuntos
Genoma Bacteriano , Genômica/métodos , Streptomyces/genética , Proteínas de Bactérias/genética , Família Multigênica , Filogenia , Deleção de Sequência
5.
Microb Cell Fact ; 18(1): 16, 2019 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-30691531

RESUMO

BACKGROUND: Streptomyces chattanoogensis L10 is the industrial producer of natamycin and has been proved a highly efficient host for diverse natural products. It has an enormous potential to be developed as a versatile cell factory for production of heterologous secondary metabolites. Here we developed a genome-reduced industrial Streptomyces chassis by rational 'design-build-test' pipeline. RESULTS: To identify candidate large non-essential genomic regions accurately and design large deletion rationally, we performed genome analyses of S. chattanoogensis L10 by multiple computational approaches, optimized Cre/loxP recombination system for high-efficient large deletion and constructed a series of universal suicide plasmids for rapid loxP or loxP mutant sites inserting into genome. Subsequently, two genome-streamlined mutants, designated S. chattanoogensis L320 and L321, were rationally constructed by depletion of 1.3 Mb and 0.7 Mb non-essential genomic regions, respectively. Furthermore, several biological performances like growth cycle, secondary metabolite profile, hyphae morphological engineering, intracellular energy (ATP) and reducing power (NADPH/NADP+) levels, transformation efficiency, genetic stability, productivity of heterologous proteins and secondary metabolite were systematically evaluated. Finally, our results revealed that L321 could serve as an efficient chassis for the production of polyketides. CONCLUSIONS: Here we developed the combined strategy of multiple computational approaches and site-specific recombination system to rationally construct genome-reduced Streptomyces hosts with high efficiency. Moreover, a genome-reduced industrial Streptomyces chassis S. chattanoogensis L321 was rationally constructed by the strategy, and the chassis exhibited several emergent and excellent performances for heterologous expression of secondary metabolite. The strategy could be widely applied in other Streptomyces to generate miscellaneous and versatile chassis with minimized genome. These chassis can not only serve as cell factories for high-efficient production of valuable polyketides, but also will provide great support for the upgrade of microbial pharmaceutical industry and drug discovery.


Assuntos
Engenharia Genética , Genoma Bacteriano , Genômica , Streptomyces/genética , Proteínas de Bactérias/metabolismo , Produtos Biológicos , Técnicas de Cultura de Células , Biologia Computacional , Regulação Bacteriana da Expressão Gênica , Microbiologia Industrial , Microrganismos Geneticamente Modificados , Família Multigênica , Natamicina/biossíntese , Metabolismo Secundário
6.
Appl Microbiol Biotechnol ; 103(18): 7583-7596, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31327020

RESUMO

Fidaxomicin, an 18-membered macrolide antibiotic, is highly active against Clostridium difficile, the most common cause of diarrhea in hospitalized patients. Though the biosynthetic mechanism of fidaxomicin has been well studied, little is known about its regulatory mechanism. Here, we reported that FadR1, a LAL family transcriptional regulator in the fidaxomicin cluster of Actinoplanes deccanensis Yp-1, acts as an activator for fidaxomicin biosynthesis. The disruption of fadR1 abolished the ability to synthesize fidaxomicin, and production could be restored by reintegrating a single copy of fadR1. Overexpression of fadR1 resulted in an approximately 400 % improvement in fidaxomicin production. Electrophoretic mobility shift assays indicated that fidaxomicin biosynthesis is under the control of FadR1 through its binding to the promoter regions of fadM, fadA1-fadP2, fadS2-fadC, and fadE-fadF, respectively. And the conserved binding sites of FadR1 within the four promoter regions were determined by footprinting experiment. All results indicated that fadR1 encodes a pathway-specific positive regulator of fidaxomicin biosynthesis and upregulates the transcription levels of most of genes by binding to the four above intergenic regions. In summary, we not only clearly elucidate the regulatory mechanism of FadR1 but also provide strategies for the construction of industrial high-yield strain of fidaxomicin.


Assuntos
Actinoplanes/metabolismo , Antibacterianos/biossíntese , Proteínas de Bactérias/metabolismo , Fidaxomicina/metabolismo , Proteínas Repressoras/metabolismo , Actinoplanes/genética , Proteínas de Bactérias/genética , Vias Biossintéticas , Clostridioides difficile/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica , Proteínas Repressoras/genética
7.
Curr Microbiol ; 76(1): 95-99, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30421143

RESUMO

Streptomyces are famed producers of secondary metabolites with diverse bioactivities and structures. However, biosynthesis of natural products will consume vast precursors from primary metabolism, and some secondary metabolites are toxic to the hosts. To overcome this circumstance and over-produce secondary metabolites, one of the strategies is to over-express biosynthetic genes under strong promoters specifically expressed during secondary metabolism. For this purpose, here based on Microarray and eGFP reporter assays, we obtained a promoter thlM4p, whose activity was undetectable in the first 2 days of fermentation, but sevenfold higher than the strong promoter ermE*p in the following days. Moreover, when the positive regulator gene scnRII was driven from thlM4p, natamycin yield increased 30% compared to ermE*p. Therefore, we provide a new way to identify promoters, which is silenced during primary metabolism while strongly expressed under secondary metabolism of Streptomyces.


Assuntos
Reatores Biológicos/microbiologia , Natamicina/biossíntese , Metabolismo Secundário/genética , Streptomyces/genética , Streptomyces/metabolismo , Fermentação/genética , Regulação Bacteriana da Expressão Gênica/genética , Metiltransferases/genética , Família Multigênica/genética , Regiões Promotoras Genéticas/genética , Transcriptoma/genética
8.
Chembiochem ; 16(3): 496-502, 2015 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-25511454

RESUMO

Genomic sequencing of actinomycetes has revealed the presence of numerous gene clusters seemingly capable of natural product biosynthesis, yet most clusters are cryptic under laboratory conditions. Bioinformatics analysis of the completely sequenced genome of Streptomyces chattanoogensis L10 (CGMCC 2644) revealed a silent angucycline biosynthetic gene cluster. The overexpression of a pathway-specific activator gene under the constitutive ermE* promoter successfully triggered the expression of the angucycline biosynthetic genes. Two novel members of the angucycline antibiotic family, chattamycins A and B, were further isolated and elucidated. Biological activity assays demonstrated that chattamycin B possesses good antitumor activities against human cancer cell lines and moderate antibacterial activities. The results presented here provide a feasible method to activate silent angucycline biosynthetic gene clusters to discover potential new drug leads.


Assuntos
Antibacterianos/farmacologia , Mineração de Dados/métodos , Genoma Bacteriano , Glicosídeos/biossíntese , Família Multigênica , Oligossacarídeos/biossíntese , Streptomyces/genética , Antibacterianos/química , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Benzo(a)Antracenos/química , Benzo(a)Antracenos/farmacologia , Simulação por Computador , Regulação Bacteriana da Expressão Gênica , Glicosídeos/química , Células Hep G2/efeitos dos fármacos , Humanos , Células MCF-7/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Estrutura Molecular , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Regiões Promotoras Genéticas , Streptomyces/metabolismo
9.
Appl Microbiol Biotechnol ; 99(3): 1287-98, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25326777

RESUMO

Quorum sensing molecular γ-butyrolactones (GBL) are widely distributed among the genus Streptomyces. Their cognate receptors have been demonstrated to control secondary metabolism and/or morphological differentiation. ScgA is responsible for the biosynthesis of GBL in Streptomyces chattanoogensis. According to the genome-wide transcriptome analysis of the ΔscgA mutant, we found that the expression of sprA, which encodes a GBL receptor homologue, was shown to be positively regulated by ScgA. Electrophoretic mobility shift assays and DNase I footprinting assays showed that SprA bound to two specific autoregulatory element (ARE) sequences located upstream of the sprA gene, indicating that its expression is self-regulated. SprA was involved in biosynthesis of GBL by repressing the expression of scgA. An Escherichia coli-based luciferase report system demonstrated that SprA directly repressed the expression of scgR, which encodes a GBL receptor. Like deletion of scgA, the disruption of sprA resulted in decreased production of the antibiotic natamycin in liquid culture and retarded morphological differentiation on solid agar. This work indicates that SprA acts as a pleiotropic regulator of both morphogenesis and the production of natamycin.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Proteínas Repressoras/metabolismo , Streptomyces/genética , Transcriptoma , 4-Butirolactona/biossíntese , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Dados de Sequência Molecular , Proteínas Repressoras/química , Proteínas Repressoras/genética , Alinhamento de Sequência , Streptomyces/química , Streptomyces/metabolismo
10.
Appl Microbiol Biotechnol ; 99(6): 2715-26, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25724582

RESUMO

The roles of many sigma factors are unclear in regulatory mechanism of secondary metabolism in Streptomyces. Here, we report the regulation network of a group 3 sigma factor, WhiGch, from a natamycin industrial strain Streptomyces chattanoogensis L10. WhiGch regulates the growth and morphological differentiation of S. chattanoogensis L10. The whiG ch deletion mutant decreased natamycin production by about 30 % and delayed natamycin production more than 24 h by delaying the growth. Overexpression of the whiG ch gene increased natamycin production in large scale production medium by about 26 %. WhiGch upregulated the transcription of natamycin biosynthetic gene cluster and inhibited the expression of migrastatin and jadomycin analog biosynthetic polyketide synthase genes. WhiGch positively regulated natamycin biosynthetic gene cluster by directly binding to the promoters of scnC and scnD, which were involved in natamycin biosynthesis, and these binding sites adjacent to translation start codon were determined. Thus, this paper further elucidates the high natamycin yield mechanisms of industrial strains and demonstrates that a valuable improvement in the yield of the target metabolites can be achieved through manipulating the transcription regulators.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Natamicina/biossíntese , Fator sigma/genética , Streptomyces/genética , Sequência de Aminoácidos , Proteínas de Bactérias/metabolismo , Sequência de Bases , Fragmentação do DNA , Fermentação , Deleção de Genes , Análise em Microsséries , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Família Multigênica , Regiões Promotoras Genéticas , Fator sigma/metabolismo , Streptomyces/metabolismo
11.
Appl Environ Microbiol ; 80(22): 6879-87, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25172865

RESUMO

Detailed mechanisms of WhiB-like (Wbl) proteins involved in antibiotic biosynthesis and morphological differentiation are poorly understood. Here, we characterize the role of WblAch, a Streptomyces chattanoogensis L10 protein belonging to this superfamily. Based on DNA microarray data and verified by real-time quantitative PCR (qRT-PCR), the expression of wblAch was shown to be positively regulated by AdpAch. Gel retardation assays and DNase I footprinting experiments showed that AdpAch has specific DNA-binding activity for the promoter region of wblAch. Gene disruption and genetic complementation revealed that WblAch acts in a positive manner to regulate natamycin production. When wblAch was overexpressed in the wild-type strain, the natamycin yield was increased by ∼30%. This provides a strategy to generate improved strains for natamycin production. Moreover, transcriptional analysis showed that the expression levels of whi genes (including whiA, whiB, whiH, and whiI) were severely depressed in the ΔwblAch mutant, suggesting that WblAch plays a part in morphological differentiation by influencing the expression of the whi genes.


Assuntos
Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Natamicina/biossíntese , Streptomyces/enzimologia , Streptomyces/crescimento & desenvolvimento , Transativadores/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Dados de Sequência Molecular , Streptomyces/genética , Transativadores/genética
12.
Synth Syst Biotechnol ; 9(4): 766-774, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39021363

RESUMO

The anti-Clostridium difficile infection (CDI) drug fidaxomicin is a natural polyketide metabolite mainly produced by Micromonosporaceae, such as Actinoplanes deccanensis, Dactylosporangium aurantiacum, and Micromonospora echinospora. In the present study, we employed a stepwise strategy by combining heterologous expression, chassis construction, promoter engineering, activator and transporters overexpression, and optimization of fermentation media for high-level production of fidaxomicin. The maximum yield of 384 mg/L fidaxomicin was achieved with engineered Streptomyces albus D7-VHb in 5 L-tank bioreactor, and it was approximately 15-fold higher than the native strain Actinoplanes deccanensis YP-1 with higher strain stability and growth rate. This study developed an enhanced chassis strain, and for the first time, achieved the heterologous synthesis of fidaxomicin through a combinatorial metabolic engineering strategy.

13.
Mol Carcinog ; 52(11): 900-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22674879

RESUMO

Cisplatin is a commonly employed chemotherapy drug for lung malignancy. However its efficacy is limited by acquired drug resistance and lacking of an in vivo real-time monitoring approach. The aim of this study is to investigate the effect of cisplatin on lung adenocarcinoma cell line p53-RE-Fluc/A549 in vivo via non-invasive reporter gene by molecular imaging. For this study, we employed p53-RE-Fluc/A549 cells that overexpressed a vector with three tandem repeats of p53 response element followed by the luciferase reporter gene. P53 activity was evaluated by optical imaging and verified by Western blot after cells were exposed to 10 µM cisplatin for 72 h. The cell cycle was mainly blocked at the S- and G2/M-phases after cisplatin treatment, whereas no significant change was observed in cell apoptotic index. Increased expression of p21 and Bcl-2 as well as decreased expression of Bax were observed after cisplatin treatment by Western blotting. Longitudinal in vivo bioluminescent imaging (BLI) revealed that the p53 activity was increased from 24 to 48 h after transient cisplatin treatment in p53-RE-Fluc/A549-bearing nude mice. RNA sequencing further revealed that cell cycle and p53 signaling pathway genes, such as E2F1, CCNA2, CDK1, and CCNE2 were significantly downregulated after long-term cisplatin treatment. Thus, our study showed that cisplatin exerts its cytotoxic effect through blockage of the cell cycle and may be partly regulated by the p53 signaling pathway. Furthermore, molecular imaging is a useful tool to investigate the mechanism and evaluate the effect of chemotherapy drugs both in vivo and in vitro.


Assuntos
Antineoplásicos/uso terapêutico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Cisplatino/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Imagem Molecular , Proteína Supressora de Tumor p53/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cisplatino/farmacologia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Nus , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/análise
14.
Front Pharmacol ; 14: 1156249, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36909179

RESUMO

Purpose: The study aimed to quantify the global trends of the incidence rates of multidrug-resistant (MDR) tuberculosis (MDR-TB) and extensively drug-resistant (XDR) tuberculosis (XDR-TB). Methods: Cases, age-standardized rates (ASRs), and incidence rates of MDR-TB and XDR-TB during 2010-2019 were obtained from the Global Burden of Disease Study 2019. The incidence trends of MDR-TB and XDR-TB were evaluated using the estimated annual percentage changes (EAPCs) in ASRs. The relationships among the ASRs of MDR-TB and XDR-TB, the MDR rate, the XDR rate, and socio-demographic index (SDI) were assessed using locally weighted regression and Pearson's correlation coefficient. Results: The global ASR of MDR-TB on average decreased by 1.36% (EAPC = -1.36, 95% confidence interval [CI] = -2.19 to -0.52) per year whereas that of XDR-TB was stable (EAPC = 0.69, 95% CI = -0.15-1.54) during 2010-2019. The incidence trends of MDR-TB in most regions and countries were decreasing, but those of XDR-TB were increasing. People aged 35-44 and 55-64 years had the highest incidence rates for MDR-TB and XDR-TB. The MDR and XDR rates both peaked in those aged 35-44 years. Areas with higher SDI tended to have lower ASRs of MDR-TB (p < 0.001, ρ = -0.43). Conclusion: The current achievements for the incidence trends of MDR-TB and XDR-TB are insufficient. More strategies and tools need to be developed to further curb MDR-TB and XDR-TB, especially in high-risk areas and age groups, and in low SDI regions.

15.
Microbiol Spectr ; 11(6): e0270223, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37966201

RESUMO

IMPORTANCE: Cascade regulation networks are almost present in various kinds of microorganisms, but locating and systematically elucidating specific pleiotropic regulators related to a certain gene cluster can be a tricky problem. Here, based on the promoter of the fidaxomicin pathway-specific regulator FadR1, we utilized a "DNA to Proteins" affinity purification method and captured a global regulator MtrA, which positively regulates fidaxomicin biosynthesis. In the mtrA overexpressed strain, the production of fidaxomicin was improved by 37% compared to the native strain. Then, we combined the "Protein to DNAs" affinity purification method (DAP-seq) with the results of RNA-seq and systematically elucidated the primary and secondary metabolic processes in which MtrA directly or indirectly participates. Thus, our work brought up a new way to improve fidaxomicin production from the perspective of global regulation and analyzed the regulatory mechanism of MtrA. Meanwhile, we provided a novel methodology for the research of cascade regulation networks and vital secondary metabolites.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Regulação Bacteriana da Expressão Gênica , Fidaxomicina , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Família Multigênica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
16.
Protein Sci ; 32(4): e4617, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36882943

RESUMO

The efficiency of drug biosynthesis depends on different transcriptional regulatory pathways in Streptomyces, and the protein degradation system adds another layer of complexity to the regulatory processes. AtrA, a transcriptional regulator in the A-factor regulatory cascade, stimulates the production of daptomycin by binding to the dptE promoter in Streptomyces roseosporus. Using pull-down assays, bacterial two-hybrid system and knockout verification, we demonstrated that AtrA is a substrate for ClpP protease. Furthermore, we showed that ClpX is necessary for AtrA recognition and subsequent degradation. Bioinformatics analysis, truncating mutation, and overexpression proved that the AAA motifs of AtrA were essential for initial recognition in the degradation process. Finally, overexpression of mutated atrA (AAA-QQQ) in S. roseosporus increased the yield of daptomycin by 225% in shake flask and by 164% in the 15 L bioreactor. Thus, improving the stability of key regulators is an effective method to promote the ability of antibiotic synthesis.


Assuntos
Daptomicina , Streptomyces , Daptomicina/metabolismo , Antibacterianos/metabolismo , Regiões Promotoras Genéticas , Mutação , Tretinoína/metabolismo , Streptomyces/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
17.
Mol Cell Biochem ; 371(1-2): 77-88, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22941212

RESUMO

Cardiac hypertrophy is often associated with an increased sympathetic drive, and both in vitro and in vivo studies have demonstrated the development of cardiomyocyte hypertrophy in response to either α- or ß- adrenergic stimulation. The present study was carried out to determine whether the reversible sodium channel blocker tetrodotoxin (TTX) exerts a direct anti-hypertrophic effect on isoproterenol (ISO)-induced cell hypertrophy and find the underlying mechanism that regulate [Na(+)]( i ). The experiments were performed on cultured H9c2 cells exposed to ISO (10 µM) alone or combined with TTX (1 µM) for 48 h. Our results showed that ISO significantly increased cell surface area by 30 % and atrial natriuretic peptide gene expression by nearly twofold (p < 0.05 for both). These effects were associated with a significant reduction in the gene expression of Na(+)/K(+)-ATPase isoforms α2 and α3, whereas the α1 isoform was unaffected. Conversely, ISO increased Na(+)-H(+) exchanger 1 (NHE-1) gene expression by approximately 40 % and significantly increased [Na(+)]( i ) level by 50 % (p < 0.05 for both). ISO was also found to significantly increase aquaporin 4 gene expression by nearly ninefold (p < 0.05). All these effects were prevented when identical experiments were carried out in the presence of TTX, but the expression of NHE-1. The expression of sodium channel protein type 5 subunit alpha was unaffected by either ISO or TTX. When taken together, these studies show that TTX attenuates the hypertrophic effect of ISO and suggest a possible approach to limiting ISO-induced hypertrophy in clinical treatment.


Assuntos
Cardiotônicos/farmacologia , Isoproterenol/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Bloqueadores dos Canais de Sódio/farmacologia , Tetrodotoxina/farmacologia , Animais , Aquaporina 4/metabolismo , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Microscopia Confocal , Miócitos Cardíacos/citologia , Ratos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo
18.
Zhonghua Xin Xue Guan Bing Za Zhi ; 40(9): 723-8, 2012 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-23141082

RESUMO

OBJECTIVE: To investigate the effects of liver X receptor (LXR) agonist on adipose-derived mesenchymal stem cells (AD-MSCs) implantation into infarcted hearts of mice. METHOD: AD-MSC(Fluc+) which stably expressed firefly luciferase (Fluc) were isolated from ß-actin-Fluc transgenic mice and characterized by flow cytometry. Male FVB mice were randomly allocated into the following four groups (n = 10 each): (1) sham group; (2) MI + PBS group; (3) MI + AD-MSC(Fluc+) group; (4) MI + AD-MSC(Fluc+) + LXR agonist (T0901317) group. AD-MSC(Fluc+) or PBS were injected intramyocardial into peri-infarcted region of mice heart after permanent left anterior descending (LAD) artery ligation. Bioluminescence imaging (BLI) was performed for quantification of injected cells retention and survival. Cardiac function was evaluated by echocardiography. RESULTS: The AD-MSC(Fluc+) were positive for CD44 and CD90 by flow cytometry. BLI evidenced the firefly luciferase expression of AD-MSC(Fluc+) which was positively correlated with cell numbers (r(2) = 0.98). The results of BLI in vivo revealed that LXR agonist could improve the survival of AD-MSC(Fluc+) at day 7, 14 and 21 after transplantation compared with AD-MSC(Fluc+) alone group. Cardiac function was further improved in combination therapy group compared with AD-MSC(Fluc+) alone group (P < 0.05). CONCLUSIONS: LXR agonist T0901317 can improve the retention and survival of intramyocardial injected AD-MSC(Fluc+) post-MI, and the combination therapy of T0901317 and AD-MSC(Fluc+) has a synergetic effect on improving cardiac function in this model.


Assuntos
Hidrocarbonetos Fluorados/uso terapêutico , Transplante de Células-Tronco Mesenquimais/métodos , Infarto do Miocárdio/cirurgia , Receptores Nucleares Órfãos/agonistas , Sulfonamidas/uso terapêutico , Animais , Receptores X do Fígado , Masculino , Camundongos , Camundongos Transgênicos , Infarto do Miocárdio/mortalidade , Resultado do Tratamento
19.
Biomolecules ; 12(12)2022 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-36551276

RESUMO

Hundreds of proteins work together in microorganisms to coordinate and control normal activity in cells. Their degradation is not only the last step in the cell's lifespan but also the starting point for its recycling. In recent years, protein degradation has been extensively studied in both eukaryotic and prokaryotic organisms. Understanding the degradation process is essential for revealing the complex regulatory network in microorganisms, as well as further artificial reconstructions and applications. This review will discuss several studies on protein quality-control family members Lon, FtsH, ClpP, the proteasome in Streptomyces, and a few classical model organisms, mainly focusing on their structure, recognition mechanisms, and metabolic influences.


Assuntos
ATPases Associadas a Diversas Atividades Celulares , Complexo de Endopeptidases do Proteassoma , Proteólise , Streptomyces , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Streptomyces/enzimologia , Streptomyces/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo
20.
Front Pediatr ; 10: 882722, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35573954

RESUMO

Purpose: This study aimed to determine Down syndrome (DS) burden using years lived with disability (YLDs), years of life lost (YLLs), disability-adjusted life years (DALYs), and the trends in these parameters. Methods: We obtained the annual YLDs, YLLs, DALYs, and age-standardized rates (ASRs) of DS from 2010 to 2019 using the Global Health Data Exchange tool. The estimated annual percentage changes (EAPCs) in ASR were used to quantify and evaluate DS burden trends. Gaussian-process regression and Pearson's correlation coefficient were used to assess the relationship between DS burden and socio-demographic index (SDI). Results: Global DALYs decreased by 2.68% from 2010 to 2019 but the ASR was stable, which was mostly explained by the stability in the ASR for YLLs. The ASR of YLDs showed an increasing trend (EAPC = 1.07, 95% CI = 0.45 to 1.69). There was notable regional imbalance, with most of the DALYs or ASRs in areas with relatively low SDI. The DALY rates of DS were mostly from the YLLs of children younger than 1 year. Lower SDI areas tended to have higher DS burdens (ρ = -0.3, p < 0.001). Conclusion: This systematic analysis of the global disease burden of DS from 2010 to 2019 revealed that although the global DS DALY and YLL rate is stable, the YLD rate is increasing. And the DS burden varies significantly differences among regions or countries. The present results suggest that future strategies should focus on DS-related deaths in children younger than 1 year and the DS burden in low-SDI regions or countries, since this may be effective in further reducing DS burden.

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