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1.
Front Genet ; 15: 1363849, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38572415

RESUMO

Introduction: Autism spectrum disorder (ASD) is characterized by aberrations in social interaction and communication associated with repetitive behaviors and interests, with strong clinical heterogeneity. Genetic factors play an important role in ASD, but about 75% of ASD cases have an undetermined genetic risk. Methods: We extensively investigated an ASD cohort made of 102 families from the Middle Eastern population of Qatar. First, we investigated the copy number variations (CNV) contribution using genome-wide SNP arrays. Next, we employed Next Generation Sequencing (NGS) to identify de novo or inherited variants contributing to the ASD etiology and its associated comorbid conditions in families with complete trios (affected child and the parents). Results: Our analysis revealed 16 CNV regions located in genomic regions implicated in ASD. The analysis of the 88 ASD cases identified 41 genes in 39 ASD subjects with de novo (n = 24) or inherited variants (n = 22). We identified three novel de novo variants in new candidate genes for ASD (DTX4, ARMC6, and B3GNT3). Also, we have identified 15 de novo variants in genes that were previously implicated in ASD or related neurodevelopmental disorders (PHF21A, WASF1, TCF20, DEAF1, MED13, CREBBP, KDM6B, SMURF1, ADNP, CACNA1G, MYT1L, KIF13B, GRIA2, CHM, and KCNK9). Additionally, we defined eight novel recessive variants (RYR2, DNAH3, TSPYL2, UPF3B KDM5C, LYST, and WNK3), four of which were X-linked. Conclusion: Despite the ASD multifactorial etiology that hinders ASD genetic risk discovery, the number of identified novel or known putative ASD genetic variants was appreciable. Nevertheless, this study represents the first comprehensive characterization of ASD genetic risk in Qatar's Middle Eastern population.

2.
Ecotoxicol Environ Saf ; 272: 116070, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38340603

RESUMO

Perfluorooctanesulfonic acid (PFOS) is a neurotoxic widespread organic contaminant which affects several brain functions including memory, motor coordination and social activity. PFOS has the ability to traverse the placenta and the blood brain barrier (BBB) and cause weight gain in female mice. It's also known that obesity and consumption of a high fat diet have negative effects on the brain, impairs cognition and increases the risk for the development of dementia. The combination effect of developmental exposure to PFOS and the intake of a high-fat diet (HFD) has not been explored. This study investigates the effect of PFOS and /or HFD on weight gain, behavior and transcriptomic and proteomic analysis of adult brain mice. We found that female mice exposed to PFOS alone showed an increase in weight, while HFD expectedly increased body weight. The combination of HFD and PFOS exacerbated generalized behavior such as time spent in the center and rearing, while PFOS alone impacted the distance travelled. These results suggest that PFOS exposure may promote hyperactivity. The combination of PFOS and HFD alter social behavior such as rearing and withdrawal. Although HFD interfered with memory retrieval, biomarkers of dementia did not change except for total Tau and phosphorylated Tau. Tau was impacted by either or both PFOS exposure and HFD. Consistent with behavioral observations, global cerebral transcriptomic analysis showed that PFOS exposure affects calcium signaling, MAPK pathways, ion transmembrane transport, and developmental processes. The combination of HFD with PFOS enhances the effect of PFOS in the brain and affects pathways related to ER stress, axon guidance and extension, and neural migration. Proteomic analysis showed that HFD enhances the impact of PFOS on inflammatory pathways, regulation of cell migration and proliferation, and MAPK signaling pathways. Overall, these data show that PFOS combined with HFD may reprogram the genome and modulate neuromotor development and may promote symptoms linked to attention deficit-hyperactivity disorders (ADHD) and autism spectrum disorders (ASD). Future work will be needed to confirm these connections.


Assuntos
Ácidos Alcanossulfônicos , Demência , Fluorocarbonos , Transtornos do Neurodesenvolvimento , Gravidez , Camundongos , Animais , Feminino , Dieta Hiperlipídica/efeitos adversos , Proteômica , Aumento de Peso , Camundongos Endogâmicos C57BL
3.
Int J Mol Sci ; 24(20)2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37894896

RESUMO

The field of Alzheimer's disease (AD) has witnessed recent breakthroughs in the development of disease-modifying biologics and diagnostic markers. While immunotherapeutic interventions have provided much-awaited solutions, nucleic acid-based tools represent other avenues of intervention; however, these approaches are costly and invasive, and they have serious side effects. Previously, we have shown in AD animal models that tolfenamic acid (TA) can lower the expression of AD-related genes and their products and subsequently reduce pathological burden and improve cognition. Using TA as a scaffold and the zinc finger domain of SP1 as a pharmacophore, we developed safer and more potent brain-penetrating analogs that interfere with sequence-specific DNA binding at transcription start sites and predominantly modulate the expression of SP1 target genes. More importantly, the proteome of treated cells displayed ~75% of the downregulated products as SP1 targets. Specific levels of SP1-driven genes and AD biomarkers such as amyloid precursor protein (APP) and Tau proteins were also decreased as part of this targeted systemic response. These small molecules, therefore, offer a viable alternative to achieving desired therapeutic outcomes by interfering with both amyloid and Tau pathways with limited off-target systemic changes.


Assuntos
Doença de Alzheimer , Camundongos , Animais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Camundongos Transgênicos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , ortoaminobenzoatos/farmacologia , ortoaminobenzoatos/uso terapêutico , Proteínas tau/genética , Proteínas tau/metabolismo , Peptídeos beta-Amiloides/metabolismo
4.
Biotechnol Bioeng ; 120(11): 3335-3346, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37584190

RESUMO

The development of efficient processes for the production of oncolytic viruses (OV) plays a crucial role regarding the clinical success of virotherapy. Although many different OV platforms are currently under investigation, manufacturing of such viruses still mainly relies on static adherent cell cultures, which bear many challenges, particularly for fusogenic OVs. Availability of GMP-compliant continuous cell lines is limited, further complicating the development of commercially viable products. BHK21, AGE1. CR and HEK293 cells were previously identified as possible cell substrates for the recombinant vesicular stomatitis virus (rVSV)-based fusogenic OV, rVSV-NDV. Now, another promising cell substrate was identified, the CCX.E10 cell line, developed by Nuvonis Technologies. This suspension cell line is considered non-GMO as no foreign genes or viral sequences were used for its development. The CCX.E10 cells were thus thoroughly investigated as a potential candidate for OV production. Cell growth in the chemically defined medium in suspension resulted in concentrations up to 8.9 × 106 cells/mL with a doubling time of 26.6 h in batch mode. Cultivation and production of rVSV-NDV, was demonstrated successfully for various cultivation systems (ambr15, shake flask, stirred tank reactor, and orbitally shaken bioreactor) at vessel scales ranging from 15 mL to 10 L. High infectious virus titers of up to 4.2 × 108 TCID50 /mL were reached in orbitally shaken bioreactors and stirred tank reactors in batch mode, respectively. Our results suggest that CCX.E10 cells are a very promising option for industrial production of OVs, particularly for fusogenic VSV-based constructs.

5.
Biotechnol Bioeng ; 120(9): 2639-2657, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36779302

RESUMO

We present a proof-of-concept study for production of a recombinant vesicular stomatitis virus (rVSV)-based fusogenic oncolytic virus (OV), rVSV-Newcastle disease virus (NDV), at high cell densities (HCD). Based on comprehensive experiments in 1 L stirred tank reactors (STRs) in batch mode, first optimization studies at HCD were carried out in semi-perfusion in small-scale cultivations using shake flasks. Further, a perfusion process was established using an acoustic settler for cell retention. Growth, production yields, and process-related impurities were evaluated for three candidate cell lines (AGE1.CR, BHK-21, HEK293SF)infected at densities ranging from 15 to 30 × 106 cells/mL. The acoustic settler allowed continuous harvesting of rVSV-NDV with high cell retention efficiencies (above 97%) and infectious virus titers (up to 2.4 × 109 TCID50 /mL), more than 4-100 times higher than for optimized batch processes. No decrease in cell-specific virus yield (CSVY) was observed at HCD, regardless of the cell substrate. Taking into account the accumulated number of virions both from the harvest and bioreactor, a 15-30 fold increased volumetric virus productivity for AGE1.CR and HEK293SF was obtained compared to batch processes performed at the same scale. In contrast to all previous findings, formation of syncytia was observed at HCD for the suspension cells BHK 21 and HEK293SF. Oncolytic potency was not affected compared to production in batch mode. Overall, our study describes promising options for the establishment of perfusion processes for efficient large-scale manufacturing of fusogenic rVSV-NDV at HCD for all three candidate cell lines.


Assuntos
Vírus Oncolíticos , Animais , Vírus Oncolíticos/genética , Técnicas de Cultura de Células , Reatores Biológicos , Linhagem Celular , Vesiculovirus/genética , Cultura de Vírus
6.
Cureus ; 14(9): e29157, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36259035

RESUMO

Congenital pseudarthrosis of the clavicle (CPC) is rare. It predominantly affects the right side for an unknown reason. Most of the reported cases are diagnosed outside the neonatal period. Only two CPC cases have been reported in Saudi Arabia, where both were diagnosed during childhood. Here, we present the case of a Saudi male newborn with right-sided CPC. The diagnosis was made shortly after birth because of the uneventful cesarean delivery and painless clavicular lump. Fetuses prefer keeping their head in a right lateral position which may be a plausible explanation for the right-side predominancy in the CPC.

7.
Biomedicines ; 10(8)2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35892690

RESUMO

Parkinson's disease (PD) is a complex multifactorial disorder that is not yet fully surmised, and it is only when such a disease is tackled on multiple levels simultaneously that we should expect to see fruitful results. Gene therapy is a modern medical practice that theoretically and, so far, practically, has demonstrated its capability in joining the battle against PD and other complex disorders on most if not all fronts. This review discusses how gene therapy can efficiently replace current forms of therapy such as drugs, personalized medicine or invasive surgery. Furthermore, we discuss the importance of enhancing delivery techniques to increase the level of transduction and control of gene expression or tissue specificity. Importantly, the results of current trials establish the safety, efficacy and applicability of gene therapy for PD. Gene therapy's variety of potential in interfering with PD's pathology by improving basal ganglial circuitry, enhancing dopamine synthesis, delivering neuroprotection or preventing neurodegeneration may one day achieve symptomatic benefit, disease modification and eradication.

8.
Biomater Sci ; 10(17): 4959-4977, 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-35880637

RESUMO

The aging population contributes to an increase in the prevalence of neurodegenerative diseases, such as Parkinson's disease (PD). Due to the progressive nature of these diseases and an incomplete understanding of their pathophysiology, current drugs are inefficient, with a limited efficacy and major side effects. In this study, CRISPR-Cas9 RNA-proteins (RNP) composed of a Cas9 nuclease and single-guide RNA were delivered with a non-viral targeted delivery system to rescue the PD-associated phenotype in neuronal cells. Here, we fused the cell-penetrating amphipathic peptide, PepFect14 (PF14), with a short fragment of the rabies virus glycoprotein (C2) previously shown to have an affinity towards nicotinic acetylcholine receptors expressed on neuronal cells and on the blood-brain barrier. The resultant peptide, C2-PF14, was used to complex with and deliver RNPs to neuronal cells. We observed that RNP/C2-PF14 complexes formed nanosized, monodispersed, and nontoxic nanoparticles that led to a specific delivery into neuronal cells. α-Synuclein (α-syn) plays a major role in the pathology of PD and is considered to be a target for therapy. We demonstrated that CRISPR/Cas9 RNP delivered by C2-PF14 achieved α-syn gene (SNCA) editing in neuronal cells as determined by T7EI assay and western blotting. Furthermore, RNP/C2-PF14 relieved PD-associated toxicity in neuronal cells in vitro. This is a proof-of-concept towards simple and safe targeted genome-editing for treating PD and other neurological disorders.


Assuntos
Proteína 9 Associada à CRISPR , Doença de Parkinson , Proteína 9 Associada à CRISPR/genética , Sistemas CRISPR-Cas/genética , Edição de Genes , Humanos , Doença de Parkinson/genética , Doença de Parkinson/terapia , Peptídeos/genética , RNA
9.
Front Genome Ed ; 4: 854866, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35386234

RESUMO

The nuclease activity of the CRISPR-Cas9 system relies on the delivery of a CRISPR-associated protein 9 (Cas9) and a single guide RNA (sgRNA) against the target gene. CRISPR components are typically delivered to cells as either a Cas9/sgRNA ribonucleoprotein (RNP) complex or a plasmid encoding a Cas9 protein along with a sequence-specific sgRNA. Multiple transfection reagents are known to deliver CRISPR-Cas9 components, and delivery vectors are being developed for different purposes by several groups. Here, we repurposed a dual-fluorescence (RFP-GFP-GFP) reporter system to quantify the uptake level of the functional CRISPR-Cas9 components into cells and compare the efficiency of CRISPR delivery vectors. Using this system, we developed a novel and rapid cell-based microplate reader assay that makes possible real-time, rapid, and high throughput quantification of CRISPR nuclease activity. Cells stably expressing this dual-fluorescent reporter construct facilitated a direct quantification of the level of the internalized and functional CRISPR-Cas9 molecules into the cells without the need of co-transfecting fluorescently labeled reporter molecules. Additionally, targeting a reporter gene integrated into the genome recapitulates endogenous gene targeting. Thus, this reporter could be used to optimize various transfection conditions of CRISPR components, to evaluate and compare the efficiency of transfection agents, and to enrich cells containing desired CRISPR-induced mutations.

10.
Burns ; 48(6): 1488-1496, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34903404

RESUMO

Implementation science is a useful tool to consider ways in which we can introduce improvements to burn services in low-and-middle income countries (LMICs), where the majority of the burden of burn injury is now experienced. This paper outlines the development of the Delivery Assessment Tool (DAT), a method for facilitating quality improvement in burn services in LMICs. We used a participatory approach that ensured that local clinicians and experts were fully involved in piloting the tool. The DAT is based on internationally agreed operational standards for burn care service delivery and has undergone an iterative process of improvement and refinement through an initial three-year project in Nepal and Bangladesh. The DAT, a 50-item tool organised into 10 subsections, is used to assess a service through a participatory focus group discussion with a mixed, multidisciplinary team of staff working at the burn service, typically 6-10 participants. This usually lasts 2-3 h. The staff in the unit then select priority areas for quality improvement programmes that are within their control to achieve, which starts a cycle of audit and review. The final version of the tool was used in a further three-year project to evaluate 11 hospitals in Nepal and Bangladesh. Education and training are key components of this work; both were provided by Interburns as part of on-going support for the clinical teams. At the end of the project a>19% improvement in scores was demonstrated using the final version of the DAT in both Nepal and Bangladesh; this achievement is remarkable given the continued difficulties in service provision where patient numbers far outstrip the resources available to care for them. As a result of this work, we have made a digital version of the tool available free of charge.


Assuntos
Queimaduras , Países em Desenvolvimento , Queimaduras/terapia , Atenção à Saúde , Humanos , Pobreza , Melhoria de Qualidade
11.
Nat Commun ; 12(1): 2863, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001904

RESUMO

During injury, monocytes are recruited from the circulation to inflamed tissues and differentiate locally into mature macrophages, with prior reports showing that cavity macrophages of the peritoneum and pericardium invade deeply into the respective organs to promote repair. Here we report a dual recombinase-mediated genetic system designed to trace cavity macrophages in vivo by intersectional detection of two characteristic markers. Lineage tracing with this method shows accumulation of cavity macrophages during lung and liver injury on the surface of visceral organs without penetration into the parenchyma. Additional data suggest that these peritoneal or pleural cavity macrophages do not contribute to tissue repair and regeneration. Our in vivo genetic targeting approach thus provides a reliable method to identify and characterize cavity macrophages during their development and in tissue repair and regeneration, and distinguishes these cells from other lineages.


Assuntos
Fígado/fisiopatologia , Lesão Pulmonar/fisiopatologia , Macrófagos/fisiologia , Monócitos/fisiologia , Cavidade Peritoneal/fisiologia , Cavidade Pleural/fisiologia , Animais , Linhagem da Célula/genética , Células Cultivadas , Fígado/lesões , Ativação de Macrófagos/fisiologia , Macrófagos/citologia , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia de Fluorescência/métodos , Monócitos/citologia , Monócitos/metabolismo , Cavidade Peritoneal/citologia , Fagocitose/fisiologia , Cavidade Pleural/citologia
12.
J Microbiol Biotechnol ; 30(10): 1592-1596, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-32699196

RESUMO

The aerobic growth and metabolic performance of Escherichia coli strains BL21 and W3110 were studied when the Vitreoscilla hemoglobin (VHb) was constitutively expressed in the chromosome. When VHb was expressed, acetate production decreased in both strains and was nearly eliminated in BL21. Transcriptional levels of the glyoxylate shunt genes decreased in both strains when VHb was expressed. However, higher transcription of the α-ketoglutarate dehydrogenase genes were observed for W3110, while for BL21 transcription levels decreased. VHb expression reduced the transcription of the cytochrome bo3 genes only in BL21. These results are useful for better selecting a production host.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Hemoglobinas Truncadas/genética , Hemoglobinas Truncadas/metabolismo , Proteínas de Ligação a DNA , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Hemeproteínas , Recombinases Rec A , Transcriptoma
13.
Biotechnol Bioeng ; 116(10): 2514-2525, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31232477

RESUMO

A pUC-derived replicon inducible by oxygen limitation was designed and tested in fed-batch cultures of Escherichia coli. It included the addition of a second inducible copy of rnaII, the positive replication control element. The rnaII gene was expressed from Ptrc and cloned into pUC18 to test the hypothesis that the ratio of the positive control molecule RNAII to the negative control element, RNAI, was the determinant of plasmid copy number per chromosome (PCN). The construct was evaluated in several E. coli strains. Evaluations of the RNAII/RNAI ratio, PCN and plasmid yield normalized to biomass (YpDNA/X ) were performed and the initial hypothesis was probed. Furthermore, in high cell-density cultures in shake flasks, an outstanding amount of 126 mg/L of plasmid was produced. The microaerobically inducible plasmid was obtained by cloning the rnaII gene under the control of the oxygen-responsive Vitreoscilla stercoraria hemoglobin promoter. For this plasmid, but not for pUC18, the RNAII/RNAI ratio, PCN and YpDNA/X efficiently increased after the shift to the microaerobic regime in fed-batch cultures in a 1 L bioreactor. The YpDNA/X of the inducible plasmid reached 12 mg/g at the end of the fed-batch but the original pUC18 only reached ca. 6 mg/g. The proposed plasmid is a valuable alternative for the operation and scale-up of plasmid DNA production processes in which mass transfer limitations will not represent an issue.


Assuntos
DNA Bacteriano , Escherichia coli , Plasmídeos , Replicon , Vitreoscilla/genética , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , DNA Bacteriano/metabolismo , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Plasmídeos/genética , Plasmídeos/isolamento & purificação , Plasmídeos/metabolismo , Vitreoscilla/metabolismo
14.
Bioprocess Biosyst Eng ; 42(9): 1457-1466, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31079222

RESUMO

Escherichia coli strains W3110 and BL21 were engineered for the production of plasmid DNA (pDNA) under aerobic and transitions to microaerobic conditions. The gene coding for recombinase A (recA) was deleted in both strains. In addition, the Vitreoscilla hemoglobin (VHb) gene (vgb) was chromosomally inserted and constitutively expressed in each E. coli recA mutant and wild type. The recA inactivation increased the supercoiled pDNA fraction (SCF) in both strains, while VHb expression improved the pDNA production in W3110, but not in BL21. Therefore, a codon-optimized version of vgb was inserted in strain BL21recA-, which, together with W3110recA-vgb+, was tested in cultures with shifts from aerobic to oxygen-limited regimes. VHb expression lowered the accumulation of fermentative by-products in both strains. VHb-expressing cells displayed higher oxidative activity as indicated by the Redox Sensor Green fluorescence, which was more intense in BL21 than in W3110. Furthermore, VHb expression did not change pDNA production in W3110, but decreased it in BL21. These results are useful for understanding the physiological effects of VHb expression in two industrially relevant E. coli strains, and for the selection of a host for pDNA production.


Assuntos
Escherichia coli/metabolismo , Microrganismos Geneticamente Modificados/metabolismo , Plasmídeos/biossíntese , Aerobiose , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Cromossomos Bacterianos/genética , Cromossomos Bacterianos/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Deleção de Genes , Microrganismos Geneticamente Modificados/genética , Plasmídeos/genética , Recombinases Rec A/genética , Recombinases Rec A/metabolismo , Hemoglobinas Truncadas/biossíntese , Hemoglobinas Truncadas/genética
15.
Am J Perinatol ; 35(11): 1093-1099, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29635655

RESUMO

BACKGROUND: While anti-ß2 glycoprotein 1 (anti-ß2GP1) antibody positivity is included in the diagnostic criteria for antiphospholipid syndrome (APS), the association between anti-ß2GP1 and the obstetrical complications of APS has been inconsistently reported and remains unclear. OBJECTIVE: We completed a case-control study nested within the Canadian Ottawa and Kingston (OaK) Birth Cohort to evaluate the association between anti-ß2GP1 antibody positivity and placenta-mediated pregnancy complications. STUDY DESIGN: Five hundred cases were randomly selected among pregnant women who experienced any of the following independently adjudicated placenta-mediated pregnancy complications: preeclampsia, placental abruption, late pregnancy loss (≥ 12 weeks' gestation), and birth of a small-for-gestational age (SGA) infant < 10th percentile. Five hundred pregnant women without any placenta-mediated pregnancy complications were selected as controls. Stored blood samples were analyzed for the presence of anti-ß2GP1 antibodies by enzyme-linked immunosorbent assay. RESULTS: Anti-ß2GP1 immunoglobulin G (IgG) and/or immunoglobulin M (IgM) antibodies in titers ≥ 20 G/M units (> 99th percentile) were present in 24 of 497 (4.8%) of controls and 33 of 503 (6.6%) of cases. There was no significant difference between cases and controls for the composite outcome of any placenta-mediated pregnancy complications (odds ratio, 1.38, 95% confidence interval [CI], 0.8-2.37, p = 0.25). CONCLUSION: Our results call into question the association between anti-ß2GP1 antibodies and placenta-mediated pregnancy complications, with further research needed.


Assuntos
Anticorpos Antifosfolipídeos/sangue , Síndrome Antifosfolipídica/epidemiologia , Doenças Placentárias/epidemiologia , Complicações na Gravidez/sangue , Adulto , Síndrome Antifosfolipídica/diagnóstico , Canadá/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Doenças Placentárias/diagnóstico , Pré-Eclâmpsia/epidemiologia , Gravidez , Complicações na Gravidez/epidemiologia , Resultado da Gravidez , beta 2-Glicoproteína I/imunologia
16.
J Biol Eng ; 11: 39, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29158775

RESUMO

Oxygen-responsive promoters can be useful for synthetic biology applications, however, information on their characteristics is still limited. Here, we characterized a group of heterologous microaerobic globin promoters in Escherichia coli. Globin promoters from Bacillus subtilis, Campylobacter jejuni, Deinococcus radiodurans, Streptomyces coelicolor, Salmonella typhi and Vitreoscilla stercoraria were used to express the FMN-binding fluorescent protein (FbFP), which is a non-oxygen dependent marker. FbFP fluorescence was monitored online in cultures at maximum oxygen transfer capacities (OTRmax) of 7 and 11 mmol L-1 h-1. Different FbFP fluorescence intensities were observed and the OTRmax affected the induction level and specific fluorescence emission rate (the product of the specific fluorescence intensity multiplied by the specific growth rate) of all promoters. The promoter from S. typhi displayed the highest fluorescence emission yields (the quotient of the fluorescence intensity divided by the scattered light intensity at every time-point) and rate, and together with the promoters from D. radiodurans and S. coelicolor, the highest induction ratios. These results show the potential of diverse heterologous globin promoters for oxygen-limited processes using E. coli.

17.
BMC Biotechnol ; 17(1): 60, 2017 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-28676110

RESUMO

BACKGROUND: Dissolved oxygen tension (DOT) is hardly constant and homogenously distributed in a bioreactor, which can have a negative impact in the metabolism and product synthesis. However, the effects of DOT on plasmid DNA (pDNA) production and quality have not been thoroughly investigated. In the present study, the effects of aerobic (DOT ≥30% air sat.), microaerobic (constant DOT = 3% air sat.) and oscillatory DOT (from 0 to 100% air sat.) conditions on pDNA production, quality and host performance were characterized. RESULTS: Microaerobic conditions had little effect on pDNA production, supercoiled fraction and sequence fidelity. By contrast, oscillatory DOT caused a 22% decrease in pDNA production compared with aerobic cultures. Although in aerobic cultures the pDNA supercoiled fraction was 98%, it decreased to 80% under heterogeneous DOT conditions. The different oxygen availabilities had no effect on the fidelity of the produced pDNA. The estimated metabolic fluxes indicated substantial differences at the level of the pentose phosphate pathway and TCA cycle under different conditions. Cyclic changes in fermentative pathway fluxes, as well as fast shifts in the fluxes through cytochromes, were also estimated. Model-based genetic modifications that can potentially improve the process performance are suggested. CONCLUSIONS: DOT heterogeneities strongly affected cell performance, pDNA production and topology. This should be considered when operating or scaling-up a bioreactor with deficient mixing. Constant microaerobic conditions affected the bacterial metabolism but not the amount or quality of pDNA. Therefore, pDNA production in microaerobic cultures may be an alternative for bioreactor operation at higher oxygen transfer rates.


Assuntos
DNA Bacteriano/biossíntese , DNA Bacteriano/genética , Escherichia coli/fisiologia , Oxigênio/metabolismo , Plasmídeos/biossíntese , Plasmídeos/genética , Disponibilidade Biológica , Regulação Bacteriana da Expressão Gênica/genética , Plasmídeos/isolamento & purificação
18.
IDCases ; 9: 56-58, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28660132

RESUMO

The first Oregon case of New Delhi metallo-ß-lactamase-1 (NDM-1)-producing Escherichia coli was reported during November 2013. Epidemiologic investigation revealed only local outpatient medical care and no travel outside Oregon for both the patient and his household contact. Environmental sampling discovered a matching isolate from the patient's household vacuum cleaner, suggesting environmental persistence.

19.
ACS Synth Biol ; 6(2): 344-356, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-27715021

RESUMO

Oxygen limitation can be used as a simple environmental inducer for the expression of target genes. However, there is scarce information on the characteristics of microaerobic promoters potentially useful for cell engineering and synthetic biology applications. Here, we characterized the Vitreoscilla hemoglobin promoter (Pvgb) and a set of microaerobic endogenous promoters in Escherichia coli. Oxygen-limited cultures at different maximum oxygen transfer rates were carried out. The FMN-binding fluorescent protein (FbFP), which is a nonoxygen dependent marker protein, was used as a reporter. Fluorescence and fluorescence emission rates under oxygen-limited conditions were the highest when FbFP was under transcriptional control of PadhE, Ppfl and Pvgb. The lengths of the E. coli endogenous promoters were shortened by 60%, maintaining their key regulatory elements. This resulted in improved promoter activity in most cases, particularly for PadhE, Ppfl and PnarK. Selected promoters were also evaluated using an engineered E. coli strain expressing Vitreoscilla hemoglobin (VHb). The presence of the VHb resulted in a better repression using these promoters under aerobic conditions, and increased the specific growth and fluorescence emission rates under oxygen-limited conditions. These results are useful for the selection of promoters for specific applications and for the design of modified artificial promoters.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Oxigênio/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas de Bactérias/genética , Engenharia Celular/métodos , Proteínas de Escherichia coli/genética , Fluorescência , Regulação Bacteriana da Expressão Gênica/genética , Proteínas Luminescentes/genética , Biologia Sintética/métodos , Transcrição Gênica/genética , Hemoglobinas Truncadas/genética , Vitreoscilla/genética
20.
Artigo em Inglês | MEDLINE | ID: mdl-27795386

RESUMO

Carbapenem-resistant Enterobacteriaceae (CRE) are an urgent public health threat. We evaluated the capacity of the Carba NP test to detect carbapenemase production in 206 isolates: 143 Enterobacteriaceae identified by Oregon's CRE surveillance program in 2013 and 63 known carbapenemase-positive organisms. Overall, test sensitivity and specificity were 89% (59/66 isolates; 95% confidence interval [CI], 81 to 97%) and 100% (140/140 isolates; 95% CI, 98 to 100%), respectively. All KPC, NDM-1, VIM, and IMP producers but no (0/7 isolates) OXA-48-like strains were Carba NP positive prior to a post hoc protocol modification. We subsequently incorporated Carba NP into Oregon's CRE screening algorithm.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Carbapenêmicos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , beta-Lactamases/genética , Proteínas de Bactérias/classificação , Proteínas de Bactérias/metabolismo , Enterobacteriaceae/crescimento & desenvolvimento , Enterobacteriaceae/patogenicidade , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Expressão Gênica , Humanos , Testes de Sensibilidade Microbiana , Sensibilidade e Especificidade , beta-Lactamases/classificação , beta-Lactamases/metabolismo
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