Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 100
Filter
1.
J Neurochem ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849977

ABSTRACT

Inhalation of hydrogen (H2) gas is therapeutically effective for cerebrovascular diseases, neurodegenerative disorders, and neonatal brain disorders including pathologies induced by anesthetic gases. To understand the mechanisms underlying the protective effects of H2 on the brain, we investigated the molecular signals affected by H2 in sevoflurane-induced neuronal cell death. We confirmed that neural progenitor cells are susceptible to sevoflurane and undergo apoptosis in the retrosplenial cortex of neonatal mice. Co-administration of 1-8% H2 gas for 3 h to sevoflurane-exposed pups suppressed elevated caspase-3-mediated apoptotic cell death and concomitantly decreased c-Jun phosphorylation and activation of the c-Jun pathway, all of which are induced by oxidative stress. Anesthesia-induced increases in lipid peroxidation and oxidative DNA damage were alleviated by H2 inhalation. Phosphoproteome analysis revealed enriched clusters of differentially phosphorylated proteins in the sevoflurane-exposed neonatal brain that included proteins involved in neuronal development and synaptic signaling. H2 inhalation modified cellular transport pathways that depend on hyperphosphorylated proteins including microtubule-associated protein family. These modifications may be involved in the protective mechanisms of H2 against sevoflurane-induced neuronal cell death.

2.
Cureus ; 16(3): e56689, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38646274

ABSTRACT

Anaplastic thyroid carcinoma, a rare type of primary thyroid cancer, is one of the most aggressive neoplasms with a poor prognosis. Many cases are in the advanced stage at the time of the initial visit, and curative treatment is impossible. Because of the highly radioresistant nature of anaplastic thyroid carcinoma, this condition cannot be properly controlled with conventional radiotherapy. Herein, we report the case of a patient with anaplastic thyroid carcinoma who underwent hypofractionated radiotherapy, attained a complete response, and is still alive more than 10 years after treatment with no evidence of disease. To overcome the high radioresistance of anaplastic thyroid carcinoma, we administered 50 Gy in 10 fractions three times a week. Furthermore, we administered paclitaxel and carboplatin sequentially before and after radiotherapy. Consequently, the patient completed treatment and reached a complete response. He is still alive more than 10 years after treatment with no evidence of disease or severe adverse events. Hypofractionated radiation therapy may provide good control of locally advanced anaplastic thyroid carcinoma.

3.
Oncol Lett ; 26(4): 439, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37664653

ABSTRACT

The aim of this study was to investigate the effectiveness of brain natriuretic peptide (BNP) as a predictor of radiological effects on the heart. A total of 41 patients with esophageal cancer who underwent chemoradiotherapy (CRT) were retrospectively investigated. The BNP levels were measured on the first day of CRT (pre-CRT) and the last day of CRT (post-CRT), and the median concentration of BNP and dosimetric parameters of the heart were calculated. The change ratio of BNP was calculated as follows: [(BNP post-CRT) - (BNP pre-CRT)]/(BNP pre-CRT). The comparison of BNP pre-CRT with post-CRT was performed using a Wilcoxon signed-rank test. The relationship between dosimetric parameters and change ratio was analyzed using Spearman's correlation coefficient. The median levels of BNP of pre-CRT and post-CRT were 10 and 22 pg/ml, respectively, and the difference was statistically significant (P<0.0001). Significant correlations (all P<0.05) were observed between the change ratio and mean dose, V5, V10, V20, and V30. Of the cohort, 14 patients developed acute-to-subacute cardiac events, such as pericardial effusion, cardiomegaly, acute exacerbation of chronic heart failure, and a decreased ejection fraction. The change ratios of BNP, V5, V10, V20, and V30 were significantly higher in patients who experienced cardiac events compared with those who did not. The results of this study showed that BNP measurement, particularly the change ratio of BNP pre- and post-CRT, may be a useful cardiac event predictor in addition to dosimetric parameters.

4.
J Biosci Bioeng ; 136(2): 109-116, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37328405

ABSTRACT

Itaconic acid (IA), a C5-dicarboxylic acid, is a potential bio-based building block for the polymer industry. There are three pathways for IA production from natural IA producers; however, most of the engineered strains were used for IA production by heterologous expression of cis-aconitate decarboxylase gene (cadA) from Aspergillus terreus. In this study, IA was produced by an engineered Corynebacterium glutamicum ATCC 13032 expressing two different types of genes from two distinct pathways. The first involves the mammalian immunoresponsive gene1 (Irg1) derived from Mus musculus. The second (termed here the trans-pathway) involves two genes from the natural IA producer Ustilago maydis which are aconitate-delta-isomerase (Adi1) and trans-aconitate decarboxylase (Tad1) genes. The constructed strains developing the two distinct IA production pathways: C. glutamicum ATCC 13032 pCH-Irg1opt and C. glutamicum ATCC 13032 pCH-Tad1optadi1opt were used for production of IA from different carbon sources. The results reflect the possibility for IA production from C. glutamicum expressing the trans-pathway (Adi1/Tad1 genes) and cis-pathway (Irg1 gene) other than the well-known cis-pathway that depends mainly on cadA gene from A. terreus. The developed strain expressing trans-pathway from U. maydis; however, proved to be better at IA production with high titers of 12.25, 11.34, and 11.02 g/L, and a molar yield of 0.22, 0.42, and 0.43 mol/mol from glucose, maltose, and sucrose, respectively, via fed-batch fermentation. The present study suggests that trans-pathway is better than cis-pathway for IA production in engineered C. glutamicum.


Subject(s)
Corynebacterium glutamicum , Animals , Mice , Corynebacterium glutamicum/genetics , Succinates/metabolism , Metabolic Networks and Pathways , Fermentation , Metabolic Engineering/methods , Mammals/genetics , Mammals/metabolism
5.
J Biosci Bioeng ; 136(1): 7-12, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37120372

ABSTRACT

Itaconic acid (IA) is a value-added chemical currently produced by Aspergillus terreus from edible glucose and starch but not from inedible lignocellulosic biomass owing to the high sensitivity to fermentation inhibitors present in the hydrolysate of lignocellulosic biomass. To produce IA from lignocellulosic biomass, a gram-positive bacterium, Corynebacterium glutamicum, with a high tolerance to fermentation inhibitors was metabolically engineered to express a fusion protein composed of cis-aconitate decarboxylase from A. terreus responsible for IA formation from cis-aconitate and a maltose-binding protein (malE) from Escherichia coli. The codon-optimized cadA_malE gene was expressed in C. glutamicum ATCC 13032, and the resulting recombinant strain produced IA from glucose. IA concentration increased 4.7-fold by the deletion of the ldh gene encoding lactate dehydrogenase. With the Δldh strain HKC2029, an 18-fold higher IA production was observed from enzymatic hydrolysate of kraft pulp as a model lignocellulosic biomass than from glucose (6.15 and 0.34 g/L, respectively). The enzymatic hydrolysate of kraft pulp contained various potential fermentation inhibitors involved in furan aldehydes, benzaldehydes, benzoic acids, cinnamic acid derivatives, and aliphatic acid. Whereas cinnamic acid derivatives severely inhibited IA production, furan aldehydes, benzoic acids, and aliphatic acid improved IA production at low concentrations. The present study suggests that lignocellulosic hydrolysate contains various potential fermentation inhibitors; however, some of them can serve as enhancers for microbial fermentation likely due to the changing of redox balance in the cell.


Subject(s)
Furans , Succinates , Biomass , Fermentation , Succinates/metabolism , Glucose/metabolism , Aldehydes
6.
Front Plant Sci ; 14: 1114935, 2023.
Article in English | MEDLINE | ID: mdl-36860899

ABSTRACT

Sorghum is the fifth most important cereal crop. Here we performed molecular genetic analyses of the 'SUGARY FETERITA' (SUF) variety, which shows typical sugary endosperm traits (e.g., wrinkled seeds, accumulation of soluble sugars, and distorted starch). Positional mapping indicated that the corresponding gene was located on the long arm of chromosome 7. Within the candidate region of 3.4 Mb, a sorghum ortholog for maize Su1 (SbSu) encoding a starch debranching enzyme ISA1 was found. Sequencing analysis of SbSu in SUF uncovered nonsynonymous single nucleotide polymorphisms (SNPs) in the coding region, containing substitutions of highly conserved amino acids. Complementation of the rice sugary-1 (osisa1) mutant line with the SbSu gene recovered the sugary endosperm phenotype. Additionally, analyzing mutants obtained from an EMS-induced mutant panel revealed novel alleles with phenotypes showing less severe wrinkles and higher Brix scores. These results suggested that SbSu was the corresponding gene for the sugary endosperm. Expression profiles of starch synthesis genes during the grain-filling stage demonstrated that a loss-of-function of SbSu affects the expression of most starch synthesis genes and revealed the fine-tuned gene regulation in the starch synthetic pathway in sorghum. Haplotype analysis using 187 diverse accessions from a sorghum panel revealed the haplotype of SUF showing severe phenotype had not been used among the landraces and modern varieties. Thus, weak alleles (showing sweet and less severe wrinkles), such as in the abovementioned EMS-induced mutants, are more valuable for grain sorghum breeding. Our study suggests that more moderate alleles (e.g. produced by genome editing) should be beneficial for improving grain sorghum.

7.
J Gen Appl Microbiol ; 68(2): 109-116, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-35831135

ABSTRACT

The aromatic compound 3-amino-4-hydroxybenzoic acid (3,4-AHBA) can be employed as a raw material for high-performance industrial plastics. The aim of this study is to produce 3,4-AHBA via a recombinant Streptomyces lividans strain containing griI and griH genes derived from Streptomyces griseus using culture medium with glucose and/or xylose, which are the main components in lignocellulosic biomass. Production of 3,4-AHBA by the recombinant S. lividans strain was successful, and the productivity was affected by the kind of sugar used as an additional carbon source. Metabolic profiles revealed that L aspartate-4-semialdehyde (ASA), a precursor of 3,4-AHBA, and coenzyme NADPH were supplied in greater amounts in xylose medium than in glucose medium. Moreover, cultivation in TSB medium with a mixed sugar (glucose/xylose) was found to be effective for 3,4-AHBA production, and optimal conditions for efficient production were designed by changing the ratio of glucose to xylose. The best productivity of 2.70 g/L was achieved using a sugar mixture of 25 g/L glucose and 25 g/L xylose, which was 1.5 times higher than the result using 50 g/L glucose alone. These results suggest that Streptomyces is a suitable candidate platform for 3,4-AHBA production from lignocellulosic biomass-derived sugars under appropriate culture conditions.


Subject(s)
Streptomyces lividans , Xylose , Aminobenzoates , Fermentation , Glucose/metabolism , Hydroxybenzoates/metabolism , Streptomyces lividans/genetics , Streptomyces lividans/metabolism , Xylose/metabolism
8.
Urol Oncol ; 40(2): 64.e1-64.e8, 2022 02.
Article in English | MEDLINE | ID: mdl-34973857

ABSTRACT

OBJECTIVES: To evaluate the effect of 6-cycle completion and earlier use of radium-233 dichloride (Ra223) on the prognosis of patients with metastatic castration-resistant prostate cancer (mCRPC). METHODS: We retrospectively evaluated 75 patients with bone metastases-predominant mCRPC who were treated with Ra223 between August 2016 and August 2021. The primary purpose of the study was to assess the effect of Ra223 completion (6 cycles) on patient prognosis, and the secondary purpose was to investigate factors associated with Ra223 incompletion (fewer than 6 cycles) and overall survival. RESULTS: The median age of the patients was 72 years. The median number of Ra223 administrations was 6 (interquartile range, 5-6), and the median Ra223 completion rate was 75%. The median time from mCRPC diagnosis to Ra223 administration was 17 months, and the median number of prior treatments was 2. Multivariable analysis indicated that unfavorable performance status (>0), prostate-specific antigen (PSA) level >10 ng/ml, extension of bone metastasis score 3 to 4, and Ra223 incompletion were significantly associated with poor overall survival. In addition, EOD 3 to 4 and 3 or more prior CRPC treatments were significantly associated with Ra223 incompletion. CONCLUSION: Six-cycle completion and earlier administration of Ra233 are potentially associated with favorable survival. Unfavorable factors (EOD 3-4 and ≥3 prior treatments) were significantly associated with Ra223 incompletion.


Subject(s)
Prostatic Neoplasms, Castration-Resistant/drug therapy , Radium/therapeutic use , Aged , Humans , Male , Prognosis , Radium/pharmacology , Retrospective Studies
9.
Bioresour Technol ; 344(Pt B): 126165, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34695585

ABSTRACT

Lignocellulosic biomass has great potential as an inedible feedstock for bioplastic synthesis, although its use is still limited compared to current edible feedstocks of glucose and starch. This review focuses on recent advances in the production of biopolymers and biomonomers from lignocellulosic feedstocks with downstream processing and chemical polymer syntheses. In microbial production, four routes composed of existing poly (lactic acid) and polyhydroxyalkanoates (PHAs) and the emerging biomonomers of itaconic acid and aromatic compounds were presented to review present challenges and future perspectives, focusing on the use of lignocellulosic feedstocks. Recently, advances in purification technologies decreased the number of processes and their environmental burden. Additionally, the unique structures and high-performance of emerging lignocellulose-based bioplastics have expanded the possibilities for the use of bioplastics. The sequence of processes provides insight into the emerging technologies that are needed for the practical use of bioplastics made from lignocellulosic biomass.


Subject(s)
Lignin , Polyhydroxyalkanoates , Biomass , Biotechnology , Starch
10.
Microb Cell Fact ; 20(1): 228, 2021 Dec 23.
Article in English | MEDLINE | ID: mdl-34949178

ABSTRACT

BACKGROUND: Bio-based aromatic compounds are of great interest to the industry, as commercial production of aromatic compounds depends exclusively on the unsustainable use of fossil resources or extraction from plant resources. γ-amino acid 3-amino-4-hydroxybenzoic acid (3,4-AHBA) serves as a precursor for thermostable bioplastics. RESULTS: Under aerobic conditions, a recombinant Corynebacterium glutamicum strain KT01 expressing griH and griI genes derived from Streptomyces griseus produced 3,4-AHBA with large amounts of amino acids as by-products. The specific productivity of 3,4-AHBA increased with decreasing levels of dissolved oxygen (DO) and was eightfold higher under oxygen limitation (DO = 0 ppm) than under aerobic conditions (DO ≥ 2.6 ppm). Metabolic profiles during 3,4-AHBA production were compared at three different DO levels (0, 2.6, and 5.3 ppm) using the DO-stat method. Results of the metabolome analysis revealed metabolic shifts in both the central metabolic pathway and amino acid metabolism at a DO of < 33% saturated oxygen. Based on this metabolome analysis, metabolic pathways were rationally designed for oxygen limitation. An ldh deletion mutant, with the loss of lactate dehydrogenase, exhibited 3.7-fold higher specific productivity of 3,4-AHBA at DO = 0 ppm as compared to the parent strain KT01 and produced 5.6 g/L 3,4-AHBA in a glucose fed-batch culture. CONCLUSIONS: Our results revealed changes in the metabolic state in response to DO concentration and provided insights into oxygen supply during fermentation and the rational design of metabolic pathways for improved production of related amino acids and their derivatives.


Subject(s)
Aminobenzoates/metabolism , Corynebacterium glutamicum/metabolism , Hydroxybenzoates/metabolism , Metabolic Engineering/methods , Oxygen/metabolism , Amino Acids/metabolism , Amino Acids, Acidic/genetics , Amino Acids, Acidic/metabolism , Bacterial Proteins/genetics , Batch Cell Culture Techniques , Corynebacterium glutamicum/genetics , Fermentation , Glucose/metabolism , L-Lactate Dehydrogenase/genetics , Metabolic Networks and Pathways , Metabolome , Sequence Deletion
11.
Essays Biochem ; 65(2): 197-212, 2021 07 26.
Article in English | MEDLINE | ID: mdl-34096577

ABSTRACT

The soil microbe Corynebacterium glutamicum is a leading workhorse in industrial biotechnology and has become famous for its power to synthetise amino acids and a range of bulk chemicals at high titre and yield. The product portfolio of the microbe is continuously expanding. Moreover, metabolically engineered strains of C. glutamicum produce more than 30 high value active ingredients, including signature molecules of raspberry, savoury, and orange flavours, sun blockers, anti-ageing sugars, and polymers for regenerative medicine. Herein, we highlight recent advances in engineering of the microbe into novel cell factories that overproduce these precious molecules from pioneering proofs-of-concept up to industrial productivity.


Subject(s)
Corynebacterium glutamicum , Amino Acids/metabolism , Biotechnology , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , Humans , Metabolic Engineering
12.
Carbohydr Polym ; 262: 117938, 2021 Jun 15.
Article in English | MEDLINE | ID: mdl-33838815

ABSTRACT

A direct production route of cellulose nanofibers (TOCN-D) from raw wood particles of paulownia using simultaneous bleaching and TEMPO oxidation process was specifically investigated and introduced. For comparison, we prepared cellulose nanofibers (TOCN-C) through a common route of TEMPO oxidation of cellulose fibers, and cellulose nanofibers with disk grinding (GCNF). FE-SEM analysis showed that the average diameter of TOCN-D (5 ± 3 nm) was similar to that of TOCN-C (6 ± 3 nm). XRD results confirmed that the crystal properties of TOCN-D and that of TOCN-C were almost the same. TOCN-D and TOCN-C showed similar chemical, thermal and optical properties in FTIR, TGA and transparency tests, respectively. The nanopaper made from TOCN-D showed high Young's modulus (13.8 GPa) and tensile strength (233 MPa), which were similar to those of TOCN-C nanopaper. Owing the aforementioned similarities, it is concluded that the TOCN-D produced through direct route is a technically, environmental-friendly and economically valuable product.


Subject(s)
Cellulose, Oxidized/chemistry , Cyclic N-Oxides/chemistry , Nanofibers/chemistry , Wood/chemistry , Cellulose/chemistry , Elastic Modulus , Oxidation-Reduction , Paper , Spectroscopy, Fourier Transform Infrared/methods , Surface Properties , Tensile Strength , X-Ray Diffraction/methods
13.
J Biosci Bioeng ; 132(2): 140-147, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33896702

ABSTRACT

Recently, a hyphae-dispersed type of filamentous fungus Aspergillus oryzae was constructed via genetic engineering, and industrial applications are expected due to the ease of handling and to the level of protein production properties. In this study, we constructed cellulase-expressing strains using wild-type and hyphae-dispersed strains to investigate the correlation between protein productivity and metabolism. Compared with the original strain, the hyphae-dispersed cellulase-expressing strain showed elevated cellulase activity, rapid glucose consumption, increased mycelial dry weight, an increased expression of cellulase genes, and activated respiration activity. Comparative metabolomic analysis showed fewer metabolites in the glycolysis and TCA cycles in the dispersed strains than in the original strains. These results indicate that the flux of carbohydrate metabolism in the hyphae-dispersed strains is smoother than that in the original strains. Such efficient metabolic flux would contribute to efficient energy conversion and to sufficient energy supply to anabolisms, such as mycelial growth and protein production. Our findings suggest that the hyphae-dispersed strains could be a useful host not only for protein production but also for the biological production of various chemicals such as organic acids.


Subject(s)
Aspergillus oryzae , Aspergillus oryzae/genetics , Aspergillus oryzae/metabolism , Carbohydrate Metabolism , Cellulase/genetics , Cellulase/metabolism , Glucose , Hyphae/metabolism
14.
J Radiat Res ; 62(3): 448-456, 2021 May 12.
Article in English | MEDLINE | ID: mdl-33823009

ABSTRACT

Lung cancer with low average iodine density measured via contrast-enhanced computed tomography (CT) using dual-energy CT technology has shown a reduced local control rate after stereotactic body radiotherapy (SBRT). The current study therefore investigated the relationship between low iodine density tumor area and its ratio and local recurrence after SBRT. Dual-energy CT was performed on the day before SBRT initiation, with a low iodine density tumor area being defined as that with an iodine density of <1.81 mg cm-3. The low iodine density tumor area, the ratio between the low iodine density tumor area and the entire tumor, and the local recurrence rate were then determined. No correlation was observed between the low iodine density tumor area and the local recurrence rate. However, tumors with a large low iodine density tumor area ratio showed an increased local recurrence rate, with the prognostic accuracy almost similar to that in previous studies using average iodine densities. Our results therefore suggest that the low iodine density tumor area ratio was a useful prognostic index after SBRT, with an accuracy comparable with that of the average iodine density.


Subject(s)
Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/radiotherapy , Iodine/chemistry , Lung Neoplasms/pathology , Lung Neoplasms/radiotherapy , Radiosurgery , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/diagnostic imaging , Cardiac Output , Female , Humans , Lung Neoplasms/diagnostic imaging , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Prognosis , ROC Curve , Tomography, X-Ray Computed , Treatment Outcome
15.
Sci Rep ; 11(1): 4532, 2021 02 25.
Article in English | MEDLINE | ID: mdl-33633216

ABSTRACT

Heterosis helps increase the biomass of many crops; however, while models for its mechanisms have been proposed, it is not yet fully understood. Here, we use a QTL analysis of the progeny of a high-biomass sorghum F1 hybrid to examine heterosis. Five QTLs were identified for culm length and were explained using the dominance model. Five resultant homozygous dominant alleles were used to develop pyramided lines, which produced biomasses like the original F1 line. Cloning of one of the uncharacterised genes (Dw7a) revealed that it encoded a MYB transcription factor, that was not yet proactively used in modern breeding, suggesting that combining classic dw1or dw3, and new (dw7a) genes is an important breeding strategy. In conclusion, heterosis is explained in this situation by the dominance model and a combination of genes that balance the shortness and early flowering of the parents, to produce F1 seed yields.


Subject(s)
Genetic Association Studies , Hybrid Vigor/genetics , Models, Genetic , Quantitative Trait Loci , Quantitative Trait, Heritable , Sorghum/genetics , Alleles , Chromosome Mapping , Cloning, Molecular , Gene Expression , Genes, Dominant , Genes, Plant , Hybridization, Genetic , Japan , Plant Breeding
16.
Microbiol Resour Announc ; 9(32)2020 Aug 06.
Article in English | MEDLINE | ID: mdl-32763926

ABSTRACT

We determined the complete and draft genome sequences of two strains of Corynebacterium glutamicum and revealed their genomic islands (GEIs). The two strains, ATCC 21799 and ATCC 31831, were found to have 3,079 and 3,109 coding sequences, respectively, with 13 GEIs each not present in the reference strain, ATCC 13032.

17.
Neuropsychopharmacol Rep ; 40(3): 246-253, 2020 09.
Article in English | MEDLINE | ID: mdl-32621575

ABSTRACT

INTRODUCTION: Recent years have witnessed a rapid rise in the incidence of mental health deterioration, such as depression and depressive symptoms. Therefore, early detection and measures of prevention have become important. This study aimed to develop a predictive method for assessing the incident risk of mental health deterioration by examining the associations between mental health and handwriting duration. METHODS: A cohort study over four years was performed with 200 university students who volunteered to participate in this study. Participants received the Uchida-Kraepelin test every April and completed the 30-item general health questionnaire to evaluate their mental health. From the stroke data obtained from the digital pen in the Uchida-Kraepelin test, two kinds of intervals were extracted. Based on these interval ratios, participants were divided into two groups. We then examined the scores of the questionnaire between the high-risk group and the low-risk group in the first year of the study. In addition, multiple logistic regression analysis was used to examine whether those in the high-risk group in the first year still belonged to the high-risk group in the fourth year. RESULTS: In the "Anxiety and Dysphoria scale" in the first year, the high-risk group had a significantly higher score than the low-risk group. Additionally, it was found that those in the high-risk group in the first year tended to still be in the high-risk group in the fourth year. CONCLUSION: These results suggested that the indicator that we developed can be used as a predictive factor for the incident risk of mental health deterioration.


Subject(s)
Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/psychology , Handwriting , Mental Health/trends , Surveys and Questionnaires , Adolescent , Cohort Studies , Depression/diagnosis , Depression/psychology , Female , Follow-Up Studies , Humans , Male , Risk Factors , Young Adult
18.
ACS Synth Biol ; 9(4): 814-826, 2020 04 17.
Article in English | MEDLINE | ID: mdl-32202411

ABSTRACT

Controlling the carbon flux into a desired pathway is important for improving product yield in metabolic engineering. After entering a cell, glucose is channeled into glycolysis and the pentose phosphate pathway (PPP), which decreases the yield of target products whose synthesis relies on NADPH as a cofactor. Here, we demonstrate redirection of carbon flux into PPP under aerobic conditions in Corynebacterium glutamicum, achieved by replacing the promoter of glucose 6-phosphate isomerase gene (pgi) with an anaerobic-specific promoter of the lactate dehydrogenase gene (ldhA). The promoter replacement increased the split ratio of carbon flux into PPP from 39 to 83% under aerobic conditions. The titer, yield, and production rate of 1,5-diaminopentane, whose synthesis requires NADPH as a cofactor, were increased by 4.6-, 4.4-, and 2.6-fold, respectively. This is the largest improvement in the production of 1,5-diaminopentane or its precursor, lysine, reported to date. After aerobic cell growth, pgi expression was automatically induced under anaerobic conditions, altering the carbon flux from PPP to glycolysis, to produce succinate in a single metabolically engineered strain. Such an automatic redirection of metabolic pathway using an oxygen-responsive switch enables two-stage fermentation for efficient production of two different compounds by a single strain, potentially reducing the production costs and time for practical applications.


Subject(s)
Carbon Cycle/genetics , Corynebacterium glutamicum , Glycolysis/genetics , Metabolic Engineering/methods , Pentose Phosphate Pathway/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Carbon Cycle/physiology , Corynebacterium glutamicum/genetics , Corynebacterium glutamicum/metabolism , Glucose-6-Phosphate Isomerase/genetics , Glucose-6-Phosphate Isomerase/metabolism , Glycolysis/physiology , Oxygen/metabolism , Pentose Phosphate Pathway/physiology
19.
Biotechnol J ; 14(6): e1800478, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30810277

ABSTRACT

3-Phenyllactic acid (PhLA) is useful as a start-up material in the pharmaceutical and biorefinery industries. To enhance the production of PhLA from glucose using recombinant Escherichia coli, the effects of glucose concentration and oxygen limitation on PhLA production are assessed in a fed-batch system using dissolved oxygen (DO)-stat method. The highest titer of PhLA (7.3 g L-1 ) is observed with a high concentration of glucose and under oxygen-limited conditions (DO = 0 ppm). Under oxygen limitation, cell growth and the formation of acetate and l-phenylalanine (Phe) by-products after 72 h of cultivation are reduced by 30%, 70%, and 81%, respectively, as compared to that under high DO conditions (DO = 5 ppm). Gene expression levels are compared between low and high DO conditions by quantitative polymerase chain reaction (qPCR) analysis. Several genes in the glycolysis (gapA and pykA), pentose phosphate (tktA), and early shikimate pathways for PhLA biosynthesis (aroF, aroG, and aroH) are upregulated under oxygen limitation. The results suggest that oxygen limitation affects metabolism in the shikimate pathway at both metabolic and transcriptional levels and that controlling the DO level is critical for enhanced production of a variety of aromatic compounds through the shikimate pathway.


Subject(s)
Lactates/metabolism , Escherichia coli/metabolism , Escherichia coli Proteins/metabolism , Gene Expression/physiology , Oxygen/metabolism , Shikimic Acid/metabolism
20.
Lab Invest ; 99(6): 793-806, 2019 06.
Article in English | MEDLINE | ID: mdl-30710119

ABSTRACT

Although inhibition of epidermal growth factor receptor (EGFR)-mediated cell signaling by the EGFR tyrosine kinase inhibitor gefitinib is highly effective against advanced non-small cell lung cancer, this drug might promote severe acute interstitial pneumonia. We previously reported that molecular hydrogen (H2) acts as a therapeutic and preventive anti-oxidant. Here, we show that treatment with H2 effectively protects the lungs of mice from severe damage caused by oral administration of gefitinib after intraperitoneal injection of naphthalene, the toxicity of which is related to oxidative stress. Drinking H2-rich water ad libitum mitigated naphthalene/gefitinib-induced weight loss and significantly improved survival, which was associated with a decrease in lung inflammation and inflammatory cytokines in the bronchoalveolar lavage fluid. Naphthalene decreased glutathione in the lung, increased malondialdehyde in the plasma, and increased 4-hydroxy-2-nonenal production in airway cells, all of which were mitigated by H2-rich water, indicating that the H2-rich water reverses cellular damage to the bronchial wall caused by oxidative stress. Finally, treatment with H2 did not interfere with the anti-tumor effects of gefitinib on a lung cancer cell line in vitro or on tumor-bearing mice in vivo. These results indicate that H2-rich water has the potential to improve quality of life during gefitinib therapy by mitigating lung injury without impairing anti-tumor activity.


Subject(s)
Acute Lung Injury/prevention & control , Antineoplastic Agents/adverse effects , Gefitinib/adverse effects , Hydrogen/therapeutic use , Lung Neoplasms/drug therapy , Acute Lung Injury/chemically induced , Animals , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Hydrogen/pharmacology , Lung/drug effects , Mice, Inbred C57BL , Naphthalenes , Oxidative Stress/drug effects , Random Allocation
SELECTION OF CITATIONS
SEARCH DETAIL
...