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1.
Foods ; 13(11)2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38890956

RESUMO

L-Arabinose isomerase (L-AI) has been commonly used as an efficient biocatalyst to produce D-tagatose via the isomerization of D-galactose. However, it remains a significant challenge to efficiently synthesize D-tagatose using the native (wild type) L-AI at an industrial scale. Hence, it is extremely urgent to redesign L-AI to improve its catalytic efficiency towards D-galactose, and herein a structure-based molecular modification of Lactobacillus plantarum CY6 L-AI (LpAI) was performed. Among the engineered LpAI, both F118M and F279I mutants showed an increased D-galactose isomerization activity. Particularly, the specific activity of double mutant F118M/F279I towards D-galactose was increased by 210.1% compared to that of the wild type LpAI (WT). Besides the catalytic activity, the substrate preference of F118M/F279I was also largely changed from L-arabinose to D-galactose. In the enzymatic production of D-tagatose, the yield and conversion ratio of F118M/F279I were increased by 81.2% and 79.6%, respectively, compared to that of WT. Furthermore, the D-tagatose production of whole cells expressing F118M/F279I displayed about 2-fold higher than that of WT cell. These results revealed that the designed site-directed mutagenesis is useful for improving the catalytic efficiency of LpAI towards D-galactose.

2.
J Agric Food Chem ; 72(25): 14274-14283, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38867465

RESUMO

ß-Alanine, a valuable ß-type amino acid, is experiencing increased demand due to its multifaceted applications in food flavoring, nutritional supplements, pharmaceuticals, and the chemical industry. Nevertheless, the sustainable biosynthesis of ß-alanine currently faces challenges due to the scarcity of robust strains, attributed to the complexities of modulating multiple genes and the inherent physiological constraints. Here, systems metabolic engineering was implemented in Escherichia coli to overcome these limitations. First, an efficient l-aspartate-α-decarboxylase (ADC) was recruited for ß-alanine biosynthesis. To conserve phosphoenolpyruvate flux, we subsequently modified the endogenous glucose assimilation system by inactivating the phosphotransferase system (PTS) and introducing an alternative non-PTS system, which increased ß-alanine production to 1.70 g/L. The supply of key precursors, oxaloacetate and l-aspartate, was synergistically improved through comprehensive modulation, including strengthening main flux and blocking bypass metabolism, which significantly increased the ß-alanine titer to 3.43 g/L. Next, the expression of ADC was optimized by promoter and untranslated region (UTR) engineering. Further transport engineering, which involved disrupting ß-alanine importer CycA and heterologously expressing ß-alanine exporter NCgI0580, improved ß-alanine production to 8.48 g/L. Additionally, corn steep liquor was used to develop a cost-effective medium. The final strain produced 74.03 g/L ß-alanine with a yield of 0.57 mol/mol glucose during fed-batch fermentation.


Assuntos
Escherichia coli , Fermentação , Glucose , Engenharia Metabólica , beta-Alanina , beta-Alanina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Glucose/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo
3.
Crit Rev Food Sci Nutr ; : 1-28, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38764407

RESUMO

D-allose, a C-3 epimer of D-glucose and an aldose-ketose isomer of D-allulose, exhibits 80% of sucrose's sweetness while being remarkably low in calories and nontoxic, making it an appealing sucrose substitute. Its diverse physiological functions, particularly potent anticancer and antitumor effects, render it a promising candidate for clinical treatment, garnering sustained attention. However, its limited availability in natural sources and the challenges associated with chemical synthesis necessitate exploring biosynthetic strategies to enhance production. This overview encapsulates recent advancements in D-allose's physicochemical properties, physiological functions, applications, and biosynthesis. It also briefly discusses the crucial role of understanding aldoketose isomerase structure and optimizing its performance in D-allose synthesis. Furthermore, it delves into the challenges and future perspectives in D-allose bioproduction. Early efforts focused on identifying and characterizing enzymes responsible for D-allose production, followed by detailed crystal structure analysis to improve performance through molecular modification. Strategies such as enzyme immobilization and implementing multi-enzyme cascade reactions, utilizing more cost-effective feedstocks, were explored. Despite progress, challenges remain, including the lack of efficient high-throughput screening methods for enzyme modification, the need for food-grade expression systems, the establishment of ordered substrate channels in multi-enzyme cascade reactions, and the development of downstream separation and purification processes.

4.
Bioresour Technol ; 400: 130685, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599349

RESUMO

D-arabitol, a versatile compound with applications in food, pharmaceutical, and biochemical industries, faces challenges in biomanufacturing due to poor chassis performance and unclear synthesis mechanisms. This study aimed to enhance the performance of Zygosaccharomyces rouxii to improve D-arabitol production. Firstly, a mutant strain Z. rouxii M075 obtained via atmospheric and room temperature plasma-mediated mutagenesis yielded 42.0 g/L of D-arabitol at 96 h, with about 50 % increase. Transcriptome-guided metabolic engineering of pathway key enzymes co-expression produced strain ZR-M3, reaching 48.9 g/L D-arabitol after 96 h fermentation. Finally, under optimized conditions, fed-batch fermentation of ZR-M3 in a 5 L bioreactor yielded an impressive D-arabitol titer of 152.8 g/L at 192 h, with a productivity of 0.8 g/L/h. This study highlights promising advancements in enhancing D-arabitol production, offering potential for more efficient biomanufacturing processes and wider industrial applications.


Assuntos
Fermentação , Engenharia Metabólica , Mutagênese , Álcoois Açúcares , Transcriptoma , Engenharia Metabólica/métodos , Álcoois Açúcares/metabolismo , Transcriptoma/genética , Reatores Biológicos , Perfilação da Expressão Gênica , Saccharomycetales/genética , Saccharomycetales/metabolismo
5.
Proc Natl Acad Sci U S A ; 121(18): e2317646121, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38648486

RESUMO

Long-distance migrations of insects contribute to ecosystem functioning but also have important economic impacts when the migrants are pests or provide ecosystem services. We combined radar monitoring, aerial sampling, and searchlight trapping, to quantify the annual pattern of nocturnal insect migration above the densely populated agricultural lands of East China. A total of ~9.3 trillion nocturnal insect migrants (15,000 t of biomass), predominantly Lepidoptera, Hemiptera, and Diptera, including many crop pests and disease vectors, fly at heights up to 1 km above this 600 km-wide region every year. Larger migrants (>10 mg) exhibited seasonal reversal of movement directions, comprising northward expansion during spring and summer, followed by southward movements during fall. This north-south transfer was not balanced, however, with southward movement in fall 0.66× that of northward movement in spring and summer. Spring and summer migrations were strongest when the wind had a northward component, while in fall, stronger movements occurred on winds that allowed movement with a southward component; heading directions of larger insects were generally close to the track direction. These findings indicate adaptations leading to movement in seasonally favorable directions. We compare our results from China with similar studies in Europe and North America and conclude that ecological patterns and behavioral adaptations are similar across the Northern Hemisphere. The predominance of pests among these nocturnal migrants has severe implications for food security and grower prosperity throughout this heavily populated region, and knowledge of their migrations is potentially valuable for forecasting pest impacts and planning timely management actions.


Assuntos
Altitude , Migração Animal , Estações do Ano , Animais , China , Migração Animal/fisiologia , Agricultura/métodos , Ecossistema , Insetos/fisiologia , Vento , Voo Animal/fisiologia
6.
Beijing Da Xue Xue Bao Yi Xue Ban ; 56(2): 253-259, 2024 Apr 18.
Artigo em Chinês | MEDLINE | ID: mdl-38595241

RESUMO

OBJECTIVE: To treat the Crohn's disease (CD) patients with ustekinumab (UST), to eva-luate their clinical and endoscopic remission, and to evaluate their transmural response (TR) and transmural healing (TH) condition using intestinal ultrasonography (IUS). METHODS: Retrospective analysis was made on patients diagnosed with CD in Peking University People's Hospital from January 2020 to August 2022, who were treated with UST for remission induction and maintenance therapy. All the patients were evaluated on both week 8 and week 16/20 after treatment, including clinical, biochemical indicators, colonoscopy and IUS examination. RESULTS: A total of 13 patients were enrolled in this study, including 11 males and 2 females. The minimum age was 23 years, the maximum age was 73 years and the mean age was 36.92 years. All the patients were in the active stage of disease before treatment, and the average Best Crohn's disease activity index (Best CDAI) score was 270.12±105.55. In week 8, the Best CDAI score of the patients decreased from 270.12±105.55 to 133.16±48.66 (t=4.977, P < 0.001). Eight patients achieved clinical remission while 5 patients remained in the active stage. Nine patients underwent colonoscopy evaluation. The average simple endoscopic score for Crohn's disease (SES-CD) score decreased from 10.71±7.14 before treatment to 6.00±7.81(t=2.483, P=0.048) in week 16/20. Four patients achieved endoscopic remission while 5 patients did not. In week 8, 5 patients achieved TR, 2 patients achieved TH, the other 6 patients did not get TR or TH. In week 16/20, 6 patients achieved TR, 3 patients achieved TH while the other 4 patients did not get TR or TH. There was no significant statistical difference in the TR effect of UST between small intestine and colon lesions (Fisher test, P > 0.999). The rate of UST transmural response in the patients who had had previous biological agent therapy was lower than those with no previous biological agent therapy, but there was no significant statistical difference (Fisher test, P=0.491). CONCLUSION: After treatment of UST, the clinical and endoscopic conditions of the CD patients had been improved, and some patients could achieve clinical remission and endoscopic remission. UST had good TR and TH effects on CD. TR might appear in week 8, and the TR effect increased in week 16/20. There was no significant statistical difference in the TR effect between small intestine and colon lesions. TR effect of UST was better in the patients who had no previous biological agent therapy than those who had had other biological agents, but the result had no significant statistical difference.


Assuntos
Doença de Crohn , Masculino , Feminino , Humanos , Adulto , Adulto Jovem , Idoso , Doença de Crohn/tratamento farmacológico , Doença de Crohn/patologia , Ustekinumab/uso terapêutico , Estudos Retrospectivos , Colonoscopia , Indução de Remissão , Resultado do Tratamento
7.
Pest Manag Sci ; 80(7): 3182-3193, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38358013

RESUMO

BACKGROUND: Peanut southern blight disease, caused by Sclerotium rolfsii, is a destructive soil-borne fungal disease. The current control measures, which mainly employ succinate dehydrogenase inhibitors, are prone to resistance and toxicity to non-target organisms. As a result, it is necessary to explore the potential of eco-friendly fungicides for this disease. RESULTS: Fourteen novel phthalide compounds incorporating amino acid moieties were designed and synthesized. The in vitro activity of analog A1 [half maximal effective concentration (EC50) = 332.21 mg L-1] was slightly lower than that of polyoxin (EC50 = 284.32 mg L-1). It was observed that on the seventh day, the curative activity of A1 at a concentration of 600.00 mg L-1 was 57.75%, while the curative activity of polyoxin at a concentration of 300.00 mg L-1 was 42.55%. These results suggested that our compound exhibited in vivo activity. Peanut plants treated with A1 showed significant agronomic improvements compared to the untreated control. Several compounds in this series exhibited superior root absorption and conduction in comparison to the endothermic fungicide thifluzamide. The growth promotion and absorption-conduction experiments demonstrated the reason for the superior in vivo activity of the target compound. Cytotoxic assays have demonstrated that this series of targeted compounds exhibit low toxicity levels toward human lo2 liver cells. CONCLUSION: Our results provide a new strategy for the design and synthesis of novel green compounds. Furthermore, the target compound A1 can serve as a lead for further development of green fungicides. © 2024 Society of Chemical Industry.


Assuntos
Aminoácidos , Desenho de Fármacos , Fungicidas Industriais , Fungicidas Industriais/farmacologia , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Aminoácidos/química , Aminoácidos/farmacologia , Arachis/química , Benzofuranos/farmacologia , Benzofuranos/síntese química , Benzofuranos/química , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Basidiomycota/efeitos dos fármacos , Basidiomycota/química , Ascomicetos/efeitos dos fármacos
8.
Plant J ; 118(2): 549-564, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38184780

RESUMO

Epigenetic regulation of gene expression plays a crucial role in plant development and environmental adaptation. The H3K4me3 and H3K27me3 have not only been discovered in the regulation of gene expression in multiple biological processes but also in responses to abiotic stresses in plants. However, evidence for the presence of both H3K4me3 and H3K27me3 on the same nucleosome is sporadic. Cold-induced deposition of bivalent H3K4me3-H3K27me3 modifications and nucleosome depletion over a considerable number of active genes is documented in potato tubers and provides clues on an additional role of the bivalent modifications. Limited by the available information of genes encoding PcG/TrxG proteins as well as their corresponding mutants in potatoes, the molecular mechanism underlying the cold-induced deposition of the bivalent mark remains elusive. In this study, we found a similar deposition of the bivalent H3K4me3-H3K27me3 mark over 2129 active genes in cold-treated Arabidopsis Col-0 seedlings. The expression levels of the bivalent mark-associated genes tend to be independent of bivalent modification levels. However, these genes were associated with greater chromatin accessibility, presumably to provide a distinct chromatin environment for gene expression. In mutants clf28 and lhp1, failure to deposit H3K27me3 in active genes upon cold treatment implies that the CLF is potentially involved in cold-induced deposition of H3K27me3, with assistance from LHP1. Failure to deposit H3K4me3 during cold treatment in atx1-2 suggests a regulatory role of ATX1 in the deposition of H3K4me3. In addition, we observed a cold-induced global reduction in nucleosome occupancy, which is potentially mediated by LHP1 in an H3K27me3-dependent manner.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Histonas/genética , Histonas/metabolismo , Nucleossomos/genética , Nucleossomos/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Epigênese Genética , Proteínas de Arabidopsis/metabolismo , Cromatina/genética , Cromatina/metabolismo , Regulação da Expressão Gênica de Plantas/genética
9.
Bioresour Technol ; 389: 129843, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37820967

RESUMO

D-tagatose holds significant importance as a functional monosaccharide with diverse applications in food, medicine, and other fields. This study aimed to explore the oxidoreductive pathway for D-tagatose production, surpassing the contemporary isomerization-mediated biosynthesis approach in order to enhance the thermodynamic equilibrium of the reactions. Initially, a novel galactitol dehydrogenase was discovered through biochemical and bioinformatics analyses. By co-expressing the galactitol dehydrogenase and xylose reductase, the oxidoreductive pathway for D-tagatose synthesis was successfully established in Bacillus subtilis. Subsequently, pathway fine-tuning was achieved via promoter regulation and dehydrogenase-mediated cofactor regeneration, resulting in 6.75-fold higher D-tagatose compared to that produced by the strain containing the unmodified promoter. Finally, optimization of fermentation conditions and medium composition produced 39.57 g/L D-tagatose in a fed-batch experiment, with a productivity of 0.33 g/L/h and a yield of 0.55 mol/mol D-galactose. These findings highlight the potential of the constructed redox pathway as an effective approach for D-tagatose production.


Assuntos
Bacillus subtilis , Hexoses , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Galactose/metabolismo , Oxirredução
10.
Bioresour Technol ; 389: 129822, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37805087

RESUMO

3-Hydroxypropionic acid (3-HP) is a top value-added chemical with multifaceted application in chemical, material, and food field. However, limited availability of robust strains and elevated fermentation costs currently impose constraints on sustainable biosynthesis of 3-HP. Herein, transporter engineering, metabolic dynamic modulation, and enzyme engineering were combined to address above limitations. First, a glucose-utilizing 3-HP biosynthetic pathway was constructed in Escherichia coli, followed by recruiting alternative glucose transport system to overcome center metabolism overflow. Next, the Cra (a transcription factor)-dependent switch was applied to autonomously fine-tune carbon flux, which alleviated growth retardation and improved the 3-HP production. Subsequently, inactivation of glycerol facilitator (GlpF) increased intracellular glycerol levels and boosted 3-HP biosynthesis, but caused toxic intermediate 3-hydroxypropionaldehyde (3-HPA) accumulation. Furthermore, semi-rational design of aldehyde dehydrogenase (YdcW) increased its activity and eliminated 3-HPA accumulation. Finally, fed-batch fermentation of the final strain resulted in 52.73 g/L 3-HP, with a yield of 0.59 mol/mol glucose.


Assuntos
Aquaporinas , Proteínas de Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Glicerol/metabolismo , Glucose/metabolismo , Engenharia Metabólica/métodos , Aquaporinas/metabolismo
11.
Front Genet ; 14: 1241201, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37560386

RESUMO

Polyploidization plays important roles in the evolution and breeding of the common wheat. Aegilops tauschii, the D-genome progenitor of the common wheat, provides a valuable pool of resistance genes to multiple diseases. Extensive studies focus on the exploration of these genes for wheat improvement. However, few studies have unveiled alternations on genome-wide expression pattern and histone modifications induced by whole-genome doubling (WGD) process. In this study, we conducted transcriptome analysis for the diploid and tetraploid Ae. taushcii lines using the leaf and root tissues. Both lines tend to display similar tissue-specific pattern. Interestingly, we found that TEs located in genic regions were depleted of the repressive histone mark H3K27me3, whereas their adjacent chromatin was enriched with H3K27me3. The tetraploid line exhibited higher levels of H3K27me3 in those regions than the diploid line, particularly for genic regions associated with TEs of the long interspersed nuclear elements (LINEs), CACTA, PIF/Harbinger, Tc1/Mariner and unclassed DNA transposon. Surprisingly, the expression levels of these TEs cognate genes were negatively associated with the levels of H3K27me3 between the tetraploid and diploid lines, suggesting the five types of TEs located within genic regions might be involved in the regulation of the ploidy-related gene expression, possibly through differential enrichment of H3K27me3 in the genic regions. These findings will help to understand the potential role of specific types of TEs on transcription in response to WGD.

12.
R Soc Open Sci ; 10(6): 230121, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37293366

RESUMO

Fifteen rhodamine B hydrazide hydrazone (RhBHH) derivatives (compounds a-o) with various substituent groups at different position and their photochromic property triggered by Cu2+ were studied to illustrate the structure photochromic response relationship (SPRR). Three of them (compounds f-h) with a para-position hydroxyl group and two meta-position halogen substituents display Cu2+-triggered photochromic which is significantly different from the previous reports. It was found that halogen atoms, which were generally considered to have no remarkable regulation effect, exhibited great influences on the photochromic behaviour of RhBHH derivatives. Detail photochromic properties of the developed photochromic system were revealed by using compound g as the model substrate, and only Cu2+ displayed high selective trigger effect. Good reversible photochromic phenomenon was observed after stimulated with visible light irradiation and dark (or heat) bleaching consecutively. Furthermore, this photochromic system could be used in the preparation of photochromic glass, special security ink, molecular logic gate and two-dimensional code for security information storage.

13.
Front Plant Sci ; 14: 1147671, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36938055

RESUMO

Aconitum carmichaeli Debx. is a traditional Chinese medicine that is cultivated in China and Japan. However, the monoculturing of this herb substantially decreases soil quality. Therefore, scientific planting management is crucial for resolving the current problems in the cultivation of A. carmichaeli. In this study, we conducted a comparative study on the soil environmental characteristics, herb growth and quality of A. carmichaeli intercropping with five local crops in two different areas. Herb growth and quality, including biomass and secondary metabolites, and rhizosphere soil environmental characteristics were measured. The results showed that the intercropping with the five local crops substantially improved the A. carmichaeli biomass and polysaccharide content, decreased the disease index, and altered three monoester diterpenoid alkaloids and three diester diterpenoid alkaloids accumulations. The intercrops also increased the soil pH, nitrogen-cycling-gene abundances, and potentially beneficial microorganism abundances, and it also changed the soil nutrient levels. Moreover, these intercropping patterns could alleviate the continuous cropping obstacles of A. carmichaeli. According to a comprehensive evaluation of the A. carmichaeli growth and quality, as well as the soil quality, the best intercropping systems were the A. carmichaeli intercropping with rice, maize, and peanut. In summary, the strip-intercropping systems could improve the A. carmichaeli growth and soil quality, and be beneficial to the sustainable ecological planting of A. carmichaeli.

14.
Hortic Res ; 10(3): uhad017, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36968186

RESUMO

Polyploid plants typically display advantages on some agronomically important traits over their diploid counterparts. Extensive studies have shown genetic, transcriptomic, and epigenetic dynamics upon polyploidization in multiple plant species. However, few studies have unveiled those alternations imposed only by ploidy level, without any interference from heterozygosity. Cultivated potato is highly heterozygous. Thus, in this study, we developed two homozygous autotetraploid lines and one homozygous diploid line in parallel from a homozygous diploid potato. We confirmed their ploidy levels using chloroplast counting and karyotyping. Oligo-FISH and genome re-sequencing validated that these potato lines are nearly homozygous. We investigated variations in phenotypes, transcription, and histone modifications between two ploidies. Both autotetraploid lines produced larger but fewer tubers than the diploid line. Interestingly, each autotetraploid line displayed ploidy-related differential expression for various genes. We also discovered a genome-wide enrichment of H3K27ac in genic regions upon whole-genome doubling (WGD). However, such enrichment was not associated with the differential gene expression between two ploidies. The tetraploid lines may exhibit better resistance to cold-induced sweetening (CIS) than the diploid line in tubers, potentially regulated through the expression of CIS-related key genes, which seems to be associated with the levels of H3K4me3 in cold-stored tubers. These findings will help to understand the impacts of autotetraploidization on dynamics of phenotypes, transcription, and histone modifications, as well as on CIS-related genes in response to cold storage.

15.
Artigo em Inglês | MEDLINE | ID: mdl-36834023

RESUMO

Hemorrhagic fever with renal syndrome (HFRS) is a rodent-borne disease that has threatened Chinese residents for nearly a century. Although comprehensive prevent and control measures were taken, the HFRS epidemic in China presents a rebounding trend in some areas. Urbanization is considered as an important influencing factor for the HFRS epidemic in recent years; however, the relevant research has not been systematically summarized. This review aims to summarize urbanization-related environmental factors and the HFRS epidemic in China and provide an overview of research perspectives. The literature review was conducted following the PRISMA protocol. Journal articles on the HFRS epidemic in both English and Chinese published before 30 June 2022 were identified from PubMed, Web of Science, and Chinese National Knowledge Infrastructure (CNKI). Inclusion criteria were defined as studies providing information on urbanization-related environmental factors and the HFRS epidemic. A total of 38 studies were included in the review. Changes brought by urbanization on population, economic development, land use, and vaccination program were found to be significantly correlated with the HFRS epidemic. By changing the ecological niche of humans-affecting the rodent population, its virus-carrying rate, and the contact opportunity and susceptibility of populations-urbanization poses a biphasic effect on the HFRS epidemic. Future studies require systematic research framework, comprehensive data sources, and effective methods and models.


Assuntos
Febre Hemorrágica com Síndrome Renal , Animais , Humanos , Febre Hemorrágica com Síndrome Renal/epidemiologia , Urbanização , Roedores , China/epidemiologia , Programas de Imunização , Incidência
16.
J Agric Food Chem ; 71(1): 522-534, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36542783

RESUMO

d-Arabitol, which is typically found in mushrooms, lichens, and higher fungi, might play an effective role in alleviating visceral fat accumulation and insulin resistance particularly for its low calorie and glycemic index. However, the regulatory mechanisms of d-arabitol for alleviating obesity and associated metabolic disorders remain poorly understood. This study aimed to investigate and analyze the underlying relationship between d-arabitol-mediated gut microbiota and obesity. The results showed that d-arabitol dramatically ameliorated body weight gain, fat accumulation, and insulin resistance in HFD-fed rats. Likewise, d-arabitol remarkably increased the relative abundance of the genera Blautia, Anaerostipes, and Phascolarctobacterium and decreased the genera Romboutsia and Clostridium_sensu_stricto_1. Furthermore, these alterations in gut microflora increased SCFAs, which in turn indirectly promoted AMPK-PGC-1α-related white adipose tissue (WAT) browning. Therefore, d-arabitol would have the potential to alleviate obesity through the gut microbiota-SCFAs-WAT browning axis. It could be considered as a sugar substitute for the obese population and diabetic patients.


Assuntos
Microbioma Gastrointestinal , Resistência à Insulina , Ratos , Animais , Camundongos , Obesidade/metabolismo , Tecido Adiposo Branco/metabolismo , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL
17.
Cell Death Differ ; 30(2): 457-474, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36477078

RESUMO

Smooth muscle cell (SMC) phenotypic switch from a quiescent 'contractile' phenotype to a dedifferentiated and proliferative state underlies the development of cardiovascular diseases (CVDs); however, our understanding of the mechanism is still incomplete. In the present study, we explored the potential role of ferroptosis, a novel nonapoptotic form of cell death, in SMC phenotypic switch and related neointimal formation. We found that ferroptotic stress was triggered in cultured dedifferentiated SMCs and arterial neointimal tissue of wire-injured mice. Moreover, pro-ferroptosis stress was activated in arterial neointimal tissue of clinical patients who underwent carotid endarterectomy. Blockade of ferroptotic stress via administration of a pharmacological inhibitor or by global genetic overexpression of glutathione peroxidase-4 (GPX4), a well-established anti-ferroptosis molecule, delayed SMC phenotype switch and arterial remodelling. Conditional SMC-specific gene delivery of GPX4 using adreno-associated virus in the carotid artery inhibited ferroptosis and prevented neointimal formation. Conversely, ferroptosis stress directly triggered dedifferentiation of SMCs. Transcriptomics analysis demonstrated that inhibition of ferroptotic stress mainly targets the mitochondrial respiratory chain and oxidative phosphorylation. Mechanistically, ferroptosis inhibition corrected the disrupted mitochondrial homeostasis in dedifferentiated SMCs, including enhanced mitochondrial ROS production, dysregulated mitochondrial dynamics, and mitochondrial hyperpolarization, and ultimately inhibited SMC phenotypic switch and growth. Copper-diacetyl-bisN4-methylthiosemicarbazone (CuATSM), an agent used for clinical molecular imaging and that potently inhibits ferroptosis, prevented SMC phenotypic switch, neointimal formation and arterial inflammation in mice. These results indicate that pro-ferroptosis stress is likely to promote SMC phenotypic switch during neointimal formation and imply that inhibition of ferroptotic stress may be a promising translational approach to treat CVDs with SMC phenotype switch.


Assuntos
Desdiferenciação Celular , Miócitos de Músculo Liso , Camundongos , Animais , Células Cultivadas , Homeostase , Miócitos de Músculo Liso/metabolismo , Músculo Liso , Proliferação de Células
18.
Bioresour Technol ; 369: 128438, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36470488

RESUMO

3-Hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3-PDO) are value-added chemicals with versatile applications in the chemical, pharmaceutical, and food industries. Nevertheless, sustainable production of 3-HP and 1,3-PDO is often limited by the lack of efficient strains and suitable fermentation configurations. Herein, attempts have been made to improve the co-production of both metabolites through metabolic engineering of Escherichia coli and process optimization. First, the 3-HP and 1,3-PDO co-biosynthetic pathways were recruited and optimized in E. coli, followed by coupling the pathways to the transhydrogenase-mediated cofactor regeneration systems that increased cofactor availability and product synthesis. Next, pathway rebalancing and block of by-product formation significantly improved 3-HP and 1,3-PDO net titer. Subsequently, glycerol flux toward 3-HP and 1,3-PDO synthesis was maximized by removing metabolic repression and fine-tuning the glycerol oxidation pathway. Lastly, the combined fermentation process optimization and two-stage pH-controlled fed-batch fermentation co-produced 140.50 g/L 3-HP and 1,3-PDO, with 0.85 mol/mol net yield.


Assuntos
Glicerol , Engenharia Metabólica , Glicerol/metabolismo , Escherichia coli/metabolismo , Propilenoglicóis/metabolismo , Fermentação , Propilenoglicol/metabolismo
19.
Bioresour Technol ; 367: 128251, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36334865

RESUMO

d-Arabitol is a top value-added compound with wide applications in the food, pharmaceutical and biochemical industries. Nevertheless, sustainable biosynthesis of d-arabitol is limited by lack of efficient strains and suitable fermentation process. Herein, metabolic engineering and process optimization were performed in Zygosaccharomyces rouxii to overcoming these limitations. Adopting systems metabolic engineering include enhancement of innate biosynthetic pathway, supply of precursor substrate d-ribulose-5P and cofactors regeneration, a novel recombinant strain ZR-5A with good performance was obtained, which boosted d-arabitol production up to 29.01 g/L, 59.31 % higher than the parent strain. Further with the optimum medium composition and fed-batch fermentation, the strain ZR-5A finally produced 149.10 g/L d-arabitol with the productivity of 1.04 g/L/h, which was the highest titer ever reported by Z.rouxii system. This is the first report on the use of metabolic engineering to construct Z. rouxii chassis for the sustainable production of d-arabitol.


Assuntos
Glucose , Zygosaccharomyces , Glucose/metabolismo , Engenharia Metabólica , Álcoois Açúcares/metabolismo , Fermentação , Zygosaccharomyces/genética , Zygosaccharomyces/metabolismo
20.
Front Microbiol ; 13: 1019444, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36312977

RESUMO

Background: The diversity in currently documented viruses and their morphological characteristics indicates the need for understanding the evolutionary characteristics of viruses. Notably, further studies are needed to obtain a comprehensive landscape of virome, the virome of host species in Yunnan province, China. Materials and methods: We implemented the metagenomic next-generation sequencing strategy to investigate the viral diversity, which involved in 465 specimens collected from bats, pangolins, monkeys, and other species. The diverse RNA viruses were analyzed, especially focusing on the genome organization, genetic divergence and phylogenetic relationships. Results: In this study, we investigated the viral composition of eight libraries from bats, pangolins, monkeys, and other species, and found several diverse RNA viruses, including the Alphacoronavirus from bat specimens. By characterizing the genome organization, genetic divergence, and phylogenetic relationships, we identified five Alphacoronavirus strains, which shared phylogenetic association with Bat-CoV-HKU8-related strains. The pestivirus-like virus related to recently identified Dongyang pangolin virus (DYPV) strains from dead pangolin specimens, suggesting that these viruses are evolving. Some genomes showed higher divergence from known species (e.g., calicivirus CS9-Cali-YN-CHN-2020), and many showed evidence of recombination events with unknown or known strains (e.g., mamastroviruses BF2-astro-YN-CHN-2020 and EV-A122 AKM5-YN-CHN-2020). The newly identified viruses showed extensive changes and could be assigned as new species, or even genus (e.g., calicivirus CS9-Cali-YN-CHN-2020 and iflavirus Ifla-YN-CHN-2020). Moreover, we identified several highly divergent RNA viruses and estimated their evolutionary characteristics among different hosts, providing data for further examination of their evolutionary dynamics. Conclusion: Overall, our study emphasizes the close association between emerging viruses and infectious diseases, and the need for more comprehensive surveys.

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