1.Studies on synthesis of polyhydroxyalkanoate consisting of 3-hydroxyvalerate by Aeromonas hydrophila.
Xiao-Yun LU ; Qiong WU ; Wan-Jiao ZHANG ; Jia JIAN ; Guo-Qiang CHEN
Chinese Journal of Biotechnology 2004;20(5):779-783
Polyhydroxyalkanoates (PHA) is a family of microbially synthesized polyesters consisting of various 3-hydroxyalkanoate monomers. Aeromonas hydrophila 4AK4 could be able to synthesize PHA copolymer consisting of 3-hydroxybutyrate (3-HB) and 3-hydroxyhexanoate (3-HHx). No data has been reported about the ability to synthesize the PHA with other monomers in A. hydrophila. In this study, propionic acid, valeric acid, heptanoic acid, nonanoic acid and undecanoic acid were used together with gluconate to find out whether A. hydrophila 4AK4 could synthesize the PHA consisting of odd carbon atom number monomers. The result showed that A. hydrophila 4AK4 could not growth when supplied with propionic acid, valeric acid, heptanoic acid and nonanoic acid and only undecanoic acid could be used to synthesize PHA. Wild type and recombinant A. hydrophila 4AK4 harboring phaA (beta-ketothiolase) and phaB (acetoacetyl-CoA reductase) were cultivated with undecanoic acid and glucose or undecanoic acid and gluconate served as carbon sources. PHA consisting of 3-HB and 3-hydroxyvalerate (3-HV) could be produced by both wild type and recombinant A. hydrophila 4AK4 and the latter could produce PHA with more 3-HB monomer. When the ratio of glucose or gluconate to undecanoic acid was 1:1, the cell dry weight (CDW) of A. hydrophila 4AK4 reached 1.14 g/L and PHA content was 60% of the CDW after cultivation for 24 h. When lauric acid and undecanoic acid were served as co-substrate, A. hydrophila 4AK4 could produce copolyester consisting of 3-HB, 3-HV and 3-HHx. Along with the increase of undecanoic acid proportion in the mixed carbon source, the 3-HV content of copolymer was increased while the 3-HB and 3-HHx content were decreased. In all cases, the CDW decreased along with the increase of undecanoic acid concentration, which indicated that undecanoic acid was not very good for A. hydrophila 4AK4 growth.
Aeromonas hydrophila
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metabolism
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Fatty Acids
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metabolism
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Glucose
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metabolism
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Lauric Acids
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metabolism
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Pentanoic Acids
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metabolism
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Polyhydroxyalkanoates
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biosynthesis
2.Nonalcoholic fatty liver disease: molecular mechanisms for the hepatic steatosis.
Clinical and Molecular Hepatology 2013;19(3):210-215
Liver plays a central role in the biogenesis of major metabolites including glucose, fatty acids, and cholesterol. Increased incidence of obesity in the modern society promotes insulin resistance in the peripheral tissues in humans, and could cause severe metabolic disorders by inducing accumulation of lipid in the liver, resulting in the progression of non-alcoholic fatty liver disease (NAFLD). NAFLD, which is characterized by increased fat depots in the liver, could precede more severe diseases such as non-alcoholic steatohepatitis (NASH), cirrhosis, and in some cases hepatocellular carcinoma. Accumulation of lipid in the liver can be traced by increased uptake of free fatty acids into the liver, impaired fatty acid beta oxidation, or the increased incidence of de novo lipogenesis. In this review, I would like to focus on the roles of individual pathways that contribute to the hepatic steatosis as a precursor for the NAFLD.
Acetyl Coenzyme A/metabolism
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Fatty Acids/metabolism
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Fatty Liver/*metabolism/pathology
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Humans
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Lipogenesis
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Mitochondria/metabolism
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Triglycerides/metabolism
3.Identification of Soluble Epoxide Hydrolase Inhibitors from the Seeds of Passiflora edulis Cultivated in Vietnam
To Dao CUONG ; Hoang THI NGOC ANH ; Tran Thu HUONG ; Pham Ngoc KHANH ; Vu Thi HA ; Tran Manh HUNG ; Young Ho KIM ; Nguyen Manh CUONG
Natural Product Sciences 2019;25(4):348-353
Soluble epoxide hydrolases (sEH) are enzymes present in all living organisms, metabolize epoxy fatty acids to 1,2-diols. sEH in the metabolism of polyunsaturated fatty acids plays a key role in inflammation. In addition, the endogenous lipid mediators in cardiovascular disease are also broken down to diols by the action of sEH that enhanced cardiovascular protection. In this study, sEH inhibitory guided fractionation led to the isolation of five phenolic compounds trans-resveratrol (1), trans-piceatannol (2), sulfuretin (3), (+)-balanophonin (4), and cassigarol E (5) from the ethanol extract of the seeds of Passiflora edulis Sims cultivated in Vietnam. The chemical structures of isolated compounds were determined by the interpretation of NMR spectral data, mass spectra, and comparison with data from the literature. The soluble epoxide hydrolase (sEH) inhibitory activity of isolated compounds was evaluated. Among them, trans-piceatannol (2) showed the most potent inhibitory activity on sEH with an IC₅₀ value of 3.4 µM. This study marks the first time that sulfuretin (3) was isolated from Passiflora edulis as well as (+)-balanophonin (4), and cassigarol E (5) were isolated from Passiflora genus.
Cardiovascular Diseases
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Epoxide Hydrolases
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Ethanol
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Fatty Acids
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Fatty Acids, Unsaturated
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Inflammation
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Metabolism
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Passiflora
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Passifloraceae
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Phenol
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Vietnam
4.Fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age.
Hong-gang TANG ; Li-hong CHEN ; Chao-geng XIAO ; Tian-xing WU
Journal of Zhejiang University. Science. B 2009;10(2):154-158
We investigated the fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture, protein, lipid and ash contents were determined by methods of Association of Analytical Chemist (AOAC) International. Fatty acid profile was determined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid (DHA) were significantly higher and eicosapentaenoic acid (EPA) content was significantly lower in the two-year-old large yellow croaker than in the one-year-old (P<0.05). No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids, or the ratio of n-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food sources of EPA and DHA.
Age Factors
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Animals
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Fatty Acids
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analysis
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Muscles
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chemistry
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Perciformes
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metabolism
6.Production of fatty acids by engineered Ogataea polymorpha.
Dao FENG ; Jiaoqi GAO ; Zhiwei GONG ; Yongjin J ZHOU
Chinese Journal of Biotechnology 2022;38(2):760-771
Fatty acids (FA) are widely used as feed stocks for the production of cosmetics, personal hygiene products, lubricants and biofuels. Ogataea polymorpha is considered as an ideal chassis for bio-manufacturing, due to its outstanding characteristics such as methylotroph, thermal-tolerance and wide substrate spectrum. In this study, we harnessed O. polymorpha for overproduction of fatty acids by engineering its fatty acid metabolism and optimizing the fermentation process. The engineered strain produced 1.86 g/L FAs under the optimized shake-flask conditions (37℃, pH 6.4, a C/N ratio of 120 and an OD600 of seed culture of 6-8). The fed-batch fermentation process was further optimized by using a dissolved oxygen (DO) control strategy. The C/N ratio of initial medium was 17.5, and the glucose medium with a C/N ratio of 120 was fed when the DO was higher than 30%. This operation resulted in a titer of 18.0 g/L FA, indicating the potential of using O. polymorpha as an efficient cell factory for the production of FA.
Culture Media
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Fatty Acids
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Fermentation
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Metabolic Engineering
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Saccharomycetales/metabolism*
7.Potential implications of ketone body metabolism changes and ketogenic therapy in the treatment of heart failure.
Qiong WANG ; Siyu YAN ; Shuyu KUANG ; Mengmeng ZHOU ; Chunling JIANG
Chinese Critical Care Medicine 2023;35(7):769-772
Heart failure (HF) has become a major challenge in the treatment of global cardiovascular diseases. Great progress has been made in the drug treatment of HF, however, rehospitalization rate and mortality of patients with HF are still high. Hence, there is an urgent need to explore new treatment strategy and new underlying pathogenic mechanisms. In recent years, some researchers have suggested that regulation of ketone body metabolism may become a potentially promising therapeutic approach for HF. Some studies showed that the oxidative utilization of fatty acids and glucose was decreased in the failing heart, accompanied by the increase of ketone body oxidative metabolism. The enhancement of ketone body metabolism in HF is a compensatory change during HF. The failing heart preferentially uses ketone body oxidation to provide energy, which helps to improve the body's cardiac function. This review will discuss the potential significance of ketone body metabolism in the treatment of HF from three aspects: normal myocardial ketone body metabolism, the change of ketone body metabolism in HF, the effect of ketogenic therapy on HF and its treatment.
Humans
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Heart Failure/metabolism*
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Myocardium/metabolism*
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Ketone Bodies/metabolism*
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Cardiovascular Diseases
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Fatty Acids/metabolism*
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Energy Metabolism
8.Imaging of Cancer Metabolism using Positron Emission Tomography.
Journal of the Korean Medical Association 2009;52(2):113-120
In the 1920's, Warburg reported an observation that cancer cells depend on glycolysis even in the presence of available oxygen likely due to impaired function of mitochondria. Since then, this Warburg s effect has been the most important hypothesis in cancer metabolism and is considered as a seventh hallmark of many human cancers. Aerobic glycolysis was originally attributable to increased bioenergetic needs in rapidly proliferating cancer cells. Recently, biosynthetic aspects of aerobic glycolysis, which reprograms cancer metabolism to synthesize macromolecules such as nucleotides, fatty acids, amino acids, etc., are under active investigation. Introduction of positron emission tomography (PET) and metabolic radiotracers including F-18 flurorodeoxyglucose (FDG) and C-11 acetate made it possible to image cancer metabolism in vivo and to renew the interests on this issue. Studies have found that cancer cells with highly glycolysis features are associated with resistance to many chemotherapeutic regimens and radiation treatment. Therefore, development of glycolytic inhibitors can have an incremental effect to conventional treatments. In addition, functional imaging with metabolic radiotracers will continuously play important roles in detecting cancers and monitoring therapeutic responses to novel anti-metabolic approaches to cancer cells.
Amino Acids
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Electrons
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Energy Metabolism
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Fatty Acids
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Glycolysis
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Humans
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Mitochondria
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Nucleotides
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Oxygen
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Positron-Emission Tomography
9.An improved extraction and nonradioactive thin-layer chromatography detection method of mycolic acid.
Siyue XU ; Yuchang DI ; Mingzhe CHI ; Youwei HU ; Xiao ZHANG ; Xuelian ZHANG
Chinese Journal of Biotechnology 2023;39(9):3827-3837
Mycolic acids (MAs), i.e. 2-alkyl, 3-hydroxy long-chain fatty acids, are the hallmark of the cell envelope of Mycobacterium tuberculosis and are related with antibiotic resistance and host immune escape. Nowadays, they've become hot target of new anti-tuberculosis drugs. There are two main methods to detect MAs, 14C metabolic labeling thin-layer chromatography (TLC) and liquid chromatograph mass spectrometer (LC-MS). However, the user qualification of 14C or the lack of standards for LC-MS hampered the easy use of this method. TLC is a common way to analyze chemical substance and can be used to analyze MAs. In this study, we used tetrabutylammonium hydroxide and methyl iodide to hydrolyze and formylate MAs from mycobacterium cell wall. Subsequently, we used diethyl ether to extract methyl mycolate. By this method, we can easily extract and analyze MA in regular biological labs. The results demonstrated that this method could be used to compare MAs of different mycobacterium in different growth phases, MAs of mycobacteria treated by anti-tuberculosis drugs or MAs of mycobacterium mutants. Therefore, we can use this method as an initial validation for the changes of MAs in researches such as new drug screening without using radioisotope or when the standards are not available.
Mycolic Acids/metabolism*
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Chromatography, Thin Layer
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Mycobacterium tuberculosis
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Fatty Acids
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Antitubercular Agents/pharmacology*
10.Lipid metabolic intermediates regulate skeletal muscle insulin sensitivity.
Acta Physiologica Sinica 2022;74(5):805-815
Skeletal muscle is the largest organ of human body, which completes 80%-90% of glucose intake stimulated by insulin, and is closely related to the occurrence and development of insulin resistance (IR). Skeletal muscle is one of the main places of lipid metabolism, and lipid metabolites participate in skeletal muscle metabolism as signal molecules. Fatty acids regulate skeletal muscle insulin sensitivity through insulin signaling pathway, inflammatory response and mitochondrial function. Saturated fatty acids (SFAs) induce insulin resistance by impairing insulin signal transduction, inducing mitochondrial dysfunction and inflammatory response, while unsaturated fatty acids reverse the adverse effects of SFAs and ameliorate IR by enhancing insulin signal transduction and anti-inflammatory effect. In addition, disorders of lipid metabolism in skeletal muscle cause accumulation of harmful metabolic intermediates, such as diacylglycerol, ceramide and long-chain acyl-coenzyme A, and induce IR by directly or indirectly damaging insulin signaling pathway. This article reviews the research progress of lipid metabolic intermediates regulating insulin sensitivity in skeletal muscle, which will help to better understand the pathogenesis of diabetes.
Humans
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Insulin Resistance/physiology*
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Muscle, Skeletal/metabolism*
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Insulin/metabolism*
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Lipid Metabolism
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Fatty Acids/metabolism*