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1.
Br J Haematol ; 200(5): 608-621, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36370064

RESUMO

In a prospective, explorative study, the donor-source difference of haploidentical family (HF), matched sibling (MS), and unrelated donors (UD) was evaluated for the outcome of haematopoietic cell transplantations (HCT) in 101 patients with acute myeloid leukaemia (AML) in complete remission (CR). To eliminate compounding effects, a uniform conditioning regimen containing antithymocyte globulin (ATG) was used. After transplantation, there was a significantly higher cumulative incidence of acute graft-versus-host disease (GVHD) in HF-HCT patients (49%, 7%, and 16% for HF-, MS- and UD-HCT respectively; p < 0.001). A quarter of acute GVHD cases observed in HF-HCT patients occurred within three days of engraftment and were characterized by diffuse skin rash, fever, weight gain, and hypoalbuminaemia. This peri-engraftment acute GVHD was not observed in MS-HCT or UD-HCT patients. Additionally, a significantly higher proportion of HF-HCT patients achieved complete donor chimaerism in the peripheral mononuclear cells at one month (88%, 46%, and 69% for HF-, MS- and UD-HCT respectively; p = 0.001). There was no significant difference in engraftment, chronic GVHD, leukaemia recurrence, non-relapse mortality, and patient survival. In patients with AML in CR who received HCT using ATG-containing conditioning, stronger donor-patient alloreactivity was observed in HF-HCT, in terms of increased acute GVHD and higher likelihood of complete donor chimaerism.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Humanos , Bussulfano/uso terapêutico , Soro Antilinfocitário/uso terapêutico , Doadores não Relacionados , Irmãos , Estudos Prospectivos , Recidiva Local de Neoplasia , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Leucemia Mieloide Aguda/terapia , Condicionamento Pré-Transplante
2.
J Korean Med Sci ; 36(23): e151, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34128593

RESUMO

BACKGROUND: This study presents outcomes of management in graft failure (GF) after allogeneic hematopoietic stem cell transplantation (HCT) and provides prognostic information including rare cases of autologous reconstitution (AR). METHODS: We analyzed risk factors and outcomes of primary and secondary GF, and occurrence of AR in 1,630 HCT recipients transplanted over period of 18 years (January 2000-September 2017) at our center. RESULTS: Primary and secondary GF occurred in 13 (0.80%), and 69 patients (10-year cumulative incidence, 4.5%) respectively. No peri-transplant variables predicted primary GF, whereas reduced intensity conditioning (RIC) regimen (relative risk [RR], 0.97-28.0, P < 0.001) and lower CD34⁺ cell dose (RR, 2.44-2.84, P = 0.002) were associated with higher risk of secondary GF in multivariate analysis. Primary GF demonstrated 100% mortality, in the secondary GF group, the 5-year Kaplan-Meier survival rate was 28.8%, relapse ensued in 18.8%, and AR was observed in 11.6% (n = 8). In survival analysis, diagnosis of aplastic anemia (AA), chronic myeloid leukemia and use of RIC had a positive impact. There were 8 patients who experienced AR, which was rarely reported after transplantation for acute leukemia. Patient shared common characteristics such as young age (median 25 years), use of RIC regimen, absence of profound neutropenia, and had advantageous survival rate of 100% during follow period without relapse. CONCLUSION: Primary GF exhibited high mortality rate. Secondary GF had 4.5% 10-year cumulative incidence, median onset of 3 months after HCT, and showed 5-year Kaplan-Meier survival of 28.8%. Diagnosis of severe AA and use of RIC was both associated with higher incidence and better survival rate in secondary GF group. AR occurred in 11.6% in secondary GF, exhibited excellent prognosis.


Assuntos
Rejeição de Enxerto/epidemiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Condicionamento Pré-Transplante/métodos , Transplante Homólogo/efeitos adversos , Adolescente , Adulto , Idoso , Feminino , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Condicionamento Pré-Transplante/efeitos adversos , Falha de Tratamento , Adulto Jovem
3.
Metab Eng ; 54: 137-144, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30953778

RESUMO

Whole-cell biotransformation is one of the promising alternative approaches to microbial fermentation for producing high-value chemicals. Baeyer-Villiger monooxygenase (BVMO)-based Escherichia coli biocatalysts have been engineered to produce industrially relevant C9 chemicals, such as n-nonanoic acid and 9-hydroxynonanoic acid, from a renewable long-chain fatty acid. The key enzyme in the biotransformation pathway (i.e., BVMO from Pseudomonans putida KT2440) was first engineered, using structure modeling-based design, to improve oxidative and thermal stabilities. Using a stable and tunable plasmid (STAPL) system, E. coli host cells were engineered to have increased plasmid stability and homogeneity of the recombinant E. coli population, as well as to optimize the level of BVMO expression. Multi-level engineering of the key enzyme in host cells, allowed recombinant E. coli expressing a fatty acid double-bond hydratase, a long-chain secondary alcohol dehydrogenase, and the engineered BVMO from P. putida KT2440 (i.e., E6BVMO_C302L/M340L), to ultimately produce C9 chemicals (i.e., n-nonanoic acid and 9-hydroxynonanoic acid) from oleic acid, with a yield of up to 6 mmoL/g dry cells. This yield was 2.4-fold greater than the yield in the control strain before engineering. Therefore, this study will contribute to the development of improved processes for the biosynthesis of industrially relevant medium chain fatty acids via whole-cell biocatalysis.


Assuntos
Proteínas de Bactérias , Escherichia coli , Ácidos Graxos , Oxigenases de Função Mista , Ácido Oleico/metabolismo , Pseudomonas putida , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Ácidos Graxos/biossíntese , Ácidos Graxos/genética , Engenharia Metabólica , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Ácido Oleico/genética , Pseudomonas putida/enzimologia , Pseudomonas putida/genética
5.
Appl Microbiol Biotechnol ; 98(13): 6085-94, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24706214

RESUMO

Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.


Assuntos
Ácido Acético/metabolismo , Etanol/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efeitos da radiação , Trifosfato de Adenosina/metabolismo , Carbono/metabolismo , Metabolismo Energético , Fermentação , Glucose/metabolismo , Análise do Fluxo Metabólico , Saccharomyces cerevisiae/crescimento & desenvolvimento , Temperatura
6.
J Biotechnol ; 392: 90-95, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38950627

RESUMO

α,ω-Dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes are valuable building blocks for the production of biopolyesters and biopolyamides. One of the key steps in producing these chemicals is the oxidation of ω-hydroxycarboxylic acids using alcohol dehydrogenases (e.g., ChnD of Acinetobacter sp. NCIMB 9871). However, the reaction and structural features of these enzymes remain mostly undiscovered. Thereby, we have investigated characteristics of ChnD based on enzyme kinetics, substrate-docking simulations, and mutation studies. Kinetic analysis revealed a distinct preference of ChnD for medium chain ω-hydroxycarboxylic acids, with the highest catalytic efficiency of 18.0 mM-1s-1 for 12-hydroxydodecanoic acid among C6 to C12 ω-hydroxycarboxylic acids. The high catalytic efficiency was attributed to the positive interactions between the carboxyl group of the substrates and the guanidino group of two arginine residues (i.e., Arg62 and Arg266) in the substrate binding site. The ChnD_R62L variant showed the increased efficiency and affinity, particularly for fatty alcohols (i.e., C6-C10) and branched-chain fatty alcohols, such as 3-methyl-2-buten-1-ol. Overall, this study contributes to the deeper understanding of medium-chain primary aliphatic alcohol dehydrogenases and their applications for the production of industrially relevant chemicals such as α,ω-dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes from renewable biomass.


Assuntos
Acinetobacter , Acinetobacter/enzimologia , Acinetobacter/genética , Especificidade por Substrato , Cinética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Simulação de Acoplamento Molecular , Oxirredutases do Álcool/metabolismo , Oxirredutases do Álcool/química , Oxirredutases do Álcool/genética , Modelos Moleculares
7.
Plant Pathol J ; 40(4): 346-357, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39117334

RESUMO

This study was carried out to screen the antifungal activity against Colletotrichum acutatum, Colletotrichum dematium, and Colletotrichum coccodes. Bacterial isolate GP-P8 from pepper soil was found to be effective against the tested pathogens with an average inhibition rate of 70.7% in in vitro dual culture assays. 16S rRNA gene sequencing analysis result showed that the effective bacterial isolate as Bacillus siamensis. Biochemical characterization of GP-P8 was also performed. According to the results, protease and cellulose, siderophore production, phosphate solubilization, starch hydrolysis, and indole-3-acetic acid production were shown by the GP-P8. Using specific primers, genes involved in the production of antibiotics, such as iturin, fengycin, difficidin, bacilysin, bacillibactin, surfactin, macrolactin, and bacillaene were also detected in B. siamensis GP-P8. Identification and analysis of volatile organic compounds through solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) revealed that acetoin and 2,3-butanediol were produced by isolate GP-P8. In vivo tests showed that GP-P8 significantly reduced the anthracnose disease caused by C. acutatum, and enhanced the growth of pepper plant. Reverse transcription polymerase chain reaction analysis of pepper fruits revealed that GP-P8 treated pepper plants showed increased expression of immune genes such as CaPR1, CaPR4, CaNPR1, CaMAPK4, CaJA2, and CaERF53. These results strongly suggest that GP-P8 could be a promising biocontrol agent against pepper anthracnose disease and possibly a pepper plant growth-promoting agent.

8.
Front Neurosci ; 17: 1149864, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37521694

RESUMO

Introduction: The abnormal hyperreactivity to food cues in individuals with binge eating behaviors could be regulated by hedonic or reward-based system, overriding the homeostatic system. The aim of the present study was to investigate whether attentional bias for food cues is affected by the level of hunger, maintaining the normal homeostatic system in individuals with binge eating behaviors. Methods: A total of 116 female participants were recruited and divided into four groups: hungry-binge eating group (BE) (n = 29), satiated BE (n = 29), hungry-control (n = 29), satiated control (n = 29). While participants completed a free-viewing task on high or low-calorie food cues, visual attentional processes were recorded using an eye tracker. Results: The results revealed that BE group showed longer initial fixation duration toward high-calorie food cues in both hunger and satiety condition in the early stage, whereas the control group showed longer initial fixation duration toward high-calorie food cues only in hunger conditions. Moreover, in the late stage, the BE group stared more at the high-calorie food cue, compared to control group regardless of hunger and satiety. Discussion: The findings suggest that automatic attentional bias for food cues in individuals with binge eating behaviors occurred without purpose or awareness is not affected by the homeostatic system, while strategic attention is focused on high-calorie food. Therefore, the attentional processing of food cues in binge eating group is regulated by hedonic system rather than homeostatic system, leading to vulnerability to binge eating.

9.
FEMS Yeast Res ; 12(6): 675-84, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22697060

RESUMO

Saccharomyces cerevisiae is an excellent ethanol producer, but is rather sensitive to high concentration of ethanol. Here, influences of ethanol on cellular membrane integrity and carbon metabolism of S. cerevisiae were investigated to rationalize mechanism involved in ethanol toxicity. Addition of 5% (v/v) ethanol did neither significantly change the permeability of the cytoplasmic membrane of the reference strain S. cerevisiae BY4741 nor of the ethanol-tolerant strain iETS3. However, the addition of ethanol resulted in a marked decrease in the mitochondrial membrane potential and in increased concentrations of intracellular reactive oxygen species (ROS). The carbon flux was redistributed under these conditions from mainly ethanol production to the TCA cycle. This redistribution was possibly a result of increased energy demand for cell maintenance that increased from about zero to 20-40 mmol ATP (g(CDW)  h)(-1) . This increase in maintenance energy might be explained by the ethanol-induced reduction of the proton motive force and the required removal of ROS. Thus, the stability of the mitochondrial membrane and subsequently the capacity to keep ROS levels low could be important factors to improve tolerance of S. cerevisiae against ethanol.


Assuntos
Carbono/metabolismo , Etanol/toxicidade , Membranas Mitocondriais/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Ciclo do Ácido Cítrico , Metabolismo Energético/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Membranas Mitocondriais/fisiologia , Saccharomyces cerevisiae/fisiologia
10.
J Biotechnol ; 356: 1-7, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35870620

RESUMO

Bacterial outer membrane vesicles (OMVs) are small unilamellar proteoliposomes, which are involved in various functions including cell to cell signaling and protein excretion. Here, we have engineered the OMVs of Escherichia coli to nano-scaled bioreactors for the degradation of ß-lactam antibiotics. This was exploited by targeting a ß-lactamase (i.e., CMY-10) into the OMVs of a hyper-vesiculating E. coli BL21(DE3) mutant. The CMY-10-containing OMVs, prepared from the E. coli mutant cultures, were able to hydrolyze ß-lactam ring of nitrocefin and meropenem to a specific rate of 6.6 × 10-8 and 3.9 × 10-12 µmol/min/µm3 of OMV, which is approximately 100 and 600-fold greater than those of E. coli-based whole-cell biocatalsyts. Furthermore, CMY-10, which was encapsulated in the engineered OMVs, was much more stable against temperature and acid stresses, as compared to free enzymes in aqueous phase. The OMV-based nano-scaled reaction system would be useful for the remediation of a variety of antibiotics pollution for food and agricultural industry.


Assuntos
Membrana Externa Bacteriana , Escherichia coli , Antibacterianos/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Escherichia coli/metabolismo , beta-Lactamas/metabolismo
11.
Sci Rep ; 9(1): 18565, 2019 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-31811237

RESUMO

Systemic lupus erythematosus (SLE) is characterized by impaired clearance of apoptotic cells. Milk fat globule epidermal growth factor 8 (MFGE8) is a protein that connects αvß3 integrin on phagocytic macrophages with phosphatidylserine on apoptotic cells. We investigated whether genetic variation of the MFGE8 gene and serum MFGE8 concentration are associated with SLE. Single nucleotide polymorphisms (SNPs) were genotyped and serum concentrations were analyzed. The rs2271715 C allele and rs3743388 G allele showed higher frequency in SLE than in healthy subjects (HSs). Three haplotypes were found among 4 SNPs (rs4945, rs1878327, rs2271715, and rs3743388): AACG, CGCG, and CGTC. CGCG haplotype was significantly more common in SLE than in HSs. rs4945 was associated with the erythrocyte sedimentation rate and rs1878327 was associated with alopecia, C-reactive protein, complement 3, anti-dsDNA antibody, and high disease activity. rs2271715 and rs3743388 were associated with renal disease, cumulative glucocorticoid dose, and cyclophosphamide and mycophenolate mofetil use. Serum MFGE8 concentrations were significantly higher in SLE than in HSs. Furthermore, the levels of MFGE8 were significantly higher in SLE than HSs of the rs2271715 CC genotype. In conclusion, MFGE8 genetic polymorphisms are associated not only with susceptibility to SLE but also with disease activity through modulation of gene expression.


Assuntos
Antígenos de Superfície/genética , Lúpus Eritematoso Sistêmico/genética , Proteínas do Leite/genética , Adulto , Antígenos de Superfície/sangue , Antígenos de Superfície/imunologia , Antígenos de Superfície/metabolismo , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica/imunologia , Predisposição Genética para Doença , Haplótipos , Voluntários Saudáveis , Humanos , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Proteínas do Leite/sangue , Proteínas do Leite/imunologia , Proteínas do Leite/metabolismo , Polimorfismo de Nucleotídeo Único , República da Coreia , Adulto Jovem
12.
Clin Lymphoma Myeloma Leuk ; 19(5): 290-299.e3, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30879987

RESUMO

BACKGROUND: Elderly patients with acute myeloid leukemia (AML) have generally had a poor prognosis with unfavorable clinical and biologic disease features. Hypomethylating agents have shown potential for treating medically unfit and elderly patients with AML. PATIENTS AND METHODS: We compared the outcomes of elderly patients with AML treated with decitabine and intensive chemotherapy (IC). RESULTS: The data from 107 patients with newly diagnosed AML aged ≥ 65 years were analyzed. The overall response rate was 38.6% and was significantly greater in the IC group than in the decitabine group (65.6% vs. 26.1%; P < .001). With a median follow-up duration of survivors of 14.8 months, the median overall survival (OS) and event-free survival were 12.3 months (95% confidence interval [CI], 10.0-14.7) and 2.0 months (95% CI, 2.0-2.0), respectively, which were not different between the 2 treatment groups. The FLT3-internal tandem duplication mutation (hazard ratio [HR], 2.637; 95% CI, 1.379-5.043; P = .003), complex karyotype (HR, 2.513; 95% CI, 1.258-5.020; P = .009), and peripheral blood blast percentage at diagnosis (HR, 1.983; 95% CI, 1.148-3.422; P = .014) were analyzed as independent prognostic factors for OS. A subgroup analysis for OS showed that IC was superior to decitabine for patients with the FLT3-internal tandem duplication mutation (P = .025) and poor risk cytogenetics, except for -7/del(7q) (P = .005), and decitabine was associated with longer OS for patients with -7/del(7q) (P = .077). CONCLUSION: Decitabine showed a similar OS to IC, despite the lower response rate in patients. The clinical outcomes of specific subgroups seemed to differ with different treatment options. Optimal therapeutic approaches for elderly patients with AML should be further examined.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Decitabina/administração & dosagem , Leucemia Mieloide Aguda/tratamento farmacológico , Indução de Remissão/métodos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antimetabólitos Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Citarabina/administração & dosagem , Citarabina/efeitos adversos , Metilação de DNA/efeitos dos fármacos , Daunorrubicina/administração & dosagem , Daunorrubicina/efeitos adversos , Decitabina/efeitos adversos , Intervalo Livre de Doença , Feminino , Seguimentos , Duplicação Gênica , Humanos , Idarubicina/administração & dosagem , Idarubicina/efeitos adversos , Infusões Intravenosas , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidade , Masculino , Prognóstico , Estudos Retrospectivos , Fatores de Tempo , Tirosina Quinase 3 Semelhante a fms/genética
13.
ACS Synth Biol ; 8(5): 1055-1066, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31018087

RESUMO

Whole cell biocatalysts can be used to convert fatty acids into various value-added products. However, fatty acid transport across cellular membranes into the cytosol of microbial cells limits substrate availability and impairs membrane integrity, which in turn decreases cell viability and bioconversion activity. Because these problems are associated with the mechanism of fatty acid transport through membranes, a whole-cell biocatalyst that can form caveolae-like structures was generated to promote substrate endocytosis. Caveolin-1 ( CAV1) expression in Escherichia coli increased both the fatty acid transport rate and intracellular fatty acid concentrations via endocytosis of the supplemented substrate. Furthermore, fatty-acid endocytosis alleviated substrate cytotoxicity in E. coli. These traits attributed to bacterial endocytosis resulted in dramatically elevated biotransformation efficiencies in fed-batch and cell-recycle reaction systems when caveolae-forming E. coli was used for the bioconversion of ricinoleic acid (12-hydroxyoctadec-9-enoic acid) to ( Z)-11-(heptanoyloxy) undec-9-enoic acid. We propose that CAV1-mediated endocytosing E. coli represents a versatile tool for the biotransformation of hydrophobic substrates.


Assuntos
Endocitose , Escherichia coli/metabolismo , Ácidos Graxos/metabolismo , Biocatálise , Biotransformação , Cavéolas/metabolismo , Caveolina 1/genética , Caveolina 1/metabolismo , Ácidos Graxos/química , Ácidos Ricinoleicos/metabolismo
15.
Sci Rep ; 8(1): 10280, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29980730

RESUMO

Baeyer-Villiger monooxygenases (BVMOs) can be used for the biosynthesis of lactones and esters from ketones. However, the BVMO-based biocatalysts are not so stable under process conditions. Thereby, this study focused on enhancing stability of the BVMO-based biocatalysts. The biotransformation of ricinoleic acid into (Z)-11-(heptanoyloxy)undec-9-enoic acid by the recombinant Escherichia coli expressing the BVMO from Pseudomonas putida and an alcohol dehydrogenase from Micrococcus luteus was used as a model system. After thorough investigation of the key factors to influence stability of the BVMO, Cys302 was identified as an engineering target. The substitution of Cys302 to Leu enabled the engineered enzyme (i.e., E6BVMOC302L) to become more stable toward oxidative and thermal stresses. The catalytic activity of E6BVMOC302L-based E. coli biocatalysts was also greater than the E6BVMO-based biocatalysts. Another factor to influence biocatalytic performance of the BVMO-based whole-cell biocatalysts was availability of carbon and energy source during biotransformations. Glucose feeding into the reaction medium led to a marked increase of final product concentrations. Overall, the bioprocess engineering to improve metabolic stability of host cells in addition to the BVMO engineering allowed us to produce (Z)-11-(heptanoyloxy)undec-9-enoic acid to a concentration of 132 mM (41 g/L) from 150 mM ricinoleic acid within 8 h.


Assuntos
Biocatálise , Escherichia coli/metabolismo , Oxigenases de Função Mista/química , Oxigenases de Função Mista/metabolismo , Pseudomonas putida/enzimologia , Ácidos Ricinoleicos/metabolismo , Sequência de Aminoácidos , Biotransformação , Oxigenases de Função Mista/genética , Mutagênese Sítio-Dirigida , Mutação , Oxirredução , Estresse Oxidativo , Conformação Proteica , Homologia de Sequência
16.
Leuk Res ; 68: 51-56, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29544132

RESUMO

This retrospective analysis compared anthracyclines (as part of an induction regimen) in 128 newly diagnosed FLT3-ITD-mutated AML patients. Induction regimens comprised high-dose daunorubicin (HD-DN; 90 mg/m2/d × 3d; n = 44), standard-dose daunorubicin (SD-DN; 45 mg/m2/d × 3d; n = 51), or idarubicin (IDA; 12 mg/m2/d × 3d; n = 33) in combination with cytarabine (100-200 mg/m2/d × 7d). Fifty-three patients showing persistent leukemia on interim bone marrow examination received a second course of induction chemotherapy comprising 2 days of daunorubicin (45 mg/m2/d) or IDA (8 or 12 mg/m2/d) in addition to 5 days of cytarabine. Complete remission (CR) rates were 77.3%, 56.9%, and 69.7% for HD-DN, SD-DN, and IDA, respectively (P = 0.101; HD-DN vs. SD-DN, P = 0.036; HD-DN vs. IDA, P = 0.453; IDA vs. SD-DN, P = 0.237). The HD-DN showed higher overall survival (OS) and event-free survival (EFS) than SD-DN and IDA: the differences between HD-DN and SD-DN (P = 0.009 for OS and P = 0.010 for EFS) were statistically significant. Results of in vitro studies using FLT3-ITD-mutated cell lines supported these findings. In conclusion, HD-DN improved the CR rate, OS, and EFS of FLT3-ITD-mutated AML patients. HD-DN also tended to yield better outcomes than IDA, though the difference was not significant. The superiority of HD-DN over IDA should be confirmed in future studies.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Daunorrubicina/uso terapêutico , Idarubicina/uso terapêutico , Quimioterapia de Indução , Leucemia Mieloide Aguda/tratamento farmacológico , Mutação , Tirosina Quinase 3 Semelhante a fms/genética , Adolescente , Adulto , Idoso , Antibióticos Antineoplásicos/administração & dosagem , Daunorrubicina/administração & dosagem , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Idarubicina/administração & dosagem , Leucemia Mieloide Aguda/genética , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Estudos Retrospectivos , Análise de Sobrevida , Adulto Jovem
17.
Sci Rep ; 6: 29406, 2016 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-27406241

RESUMO

3'-Untranslated region (3'UTR) engineering was investigated to improve solubility of heterologous proteins (e.g., Baeyer-Villiger monooxygenases (BVMOs)) in Escherichia coli. Insertion of gene fragments containing putative RNase E recognition sites into the 3'UTR of the BVMO genes led to the reduction of mRNA levels in E. coli. Importantly, the amounts of soluble BVMOs were remarkably enhanced resulting in a proportional increase of in vivo catalytic activities. Notably, this increase in biocatalytic activity correlated to the number of putative RNase E endonucleolytic cleavage sites in the 3'UTR. For instance, the biotransformation activity of the BVMO BmoF1 (from Pseudomonas fluorescens DSM50106) in E. coli was linear to the number of RNase E cleavage sites in the 3'UTR. In summary, 3'UTR engineering can be used to improve the soluble expression of heterologous enzymes, thereby fine-tuning the enzyme activity in microbial cells.


Assuntos
Regiões 3' não Traduzidas , Escherichia coli/enzimologia , Oxigenases de Função Mista/metabolismo , Engenharia de Proteínas , Biocatálise , Endorribonucleases/metabolismo , Escherichia coli/genética , Genes Bacterianos , Cinética , Oxigenases de Função Mista/genética , Especificidade por Substrato
18.
PLoS One ; 11(9): e0163265, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27681369

RESUMO

The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass.

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