• Animal Bioscience
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• 제37권3호
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• pp.437-450
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• 2024

Objective: Vanin-1 (VNN1) is a pantetheinase that catalyses the hydrolysis of pantetheine to produce pantothenic acid and cysteamine. Our previous studies have shown that the VNN1 is specifically expressed in chicken liver which negatively regulated by microRNA-122. However, the functions of the VNN1 in lipid metabolism in chicken liver haven't been elucidated. Methods: First, we detected the VNN1 mRNA expression in 4-week chickens which were fasted 24 hours. Next, knocked out VNN1 via CRISPR/Cas9 system in the chicken Leghorn Male Hepatoma cell line. Detected the lipid deposition via oil red staining and analysis the content of triglycerides (TG), low-density lipoprotein-C (LDL-C), and high-density lipoprotein-C (HDL-C) after VNN1 knockout in Leghorn Male Hepatoma cell line. Then we captured various differentially expressed genes (DEGs) between VNN1-modified LMH cells and original LMH cells by RNA-seq. Results: Firstly, fasting-induced expression of VNN1. Meanwhile, we successfully used the CRISPR/Cas9 system to achieve targeted mutations of the VNN1 in the chicken LMH cell line. Moreover, the expression level of VNN1 mRNA in LMH-KO-VNN1 cells decreased compared with that in the wild-type LMH cells (p<0.0001). Compared with control, lipid deposition was decreased after knockout VNN1 via oil red staining, meanwhile, the contents of TG and LDL-C were significantly reduced, and the content of HDL-C was increased in LMH-KO-VNN1 cells. Transcriptome sequencing showed that there were 1,335 DEGs between LMH-KO-VNN1 cells and original LMH cells. Of these DEGs, 431 were upregulated, and 904 were downregulated. Gene ontology analyses of all DEGs showed that the lipid metabolism-related pathways, such as fatty acid biosynthesis and long-chain fatty acid biosynthesis, were enriched. KEGG pathway analyses showed that "lipid metabolism pathway", "energy metabolism", and "carbohydrate metabolism" were enriched. A total of 76 DEGs were involved in these pathways, of which 29 genes were upregulated (such as cytochrome P450 family 7 subfamily A member 1, ELOVL fatty acid elongase 2, and apolipoprotein A4) and 47 genes were downregulated (such as phosphoenolpyruvate carboxykinase 1) by VNN1 knockout in the LMH cells. Conclusion: These results suggest that VNN1 plays an important role in coordinating lipid metabolism in the chicken liver.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1092-1097
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• 2009

A novel exopolysaccharide named Ebosin was produced by Streptomyces sp. 139, with medicinal activity. Its biosynthesis gene cluster (ste) has been previously identified. For the functional study of the ste7 gene in Ebosin biosynthesis, it was disrupted with a double crossover via homologous recombination. The monosaccharide composition of EPS-7m produced by the mutant strain Streptomyces sp. 139 ($ste7^-$) was found altered from that of Ebosin, with fucose decreasing remarkably. For biochemical characterization of Ste7, the ste7 gene was cloned and expressed in Escherichia coli BL21. With a continuous coupled spectrophotometric assay, Ste7 was demonstrated to have the ability of catalyzing the transfer of fucose specifically from GDP-$\beta$-L-fucose to a fucose acceptor, the lipid carrier located in the cytoplasmic membrane of Streptomyces sp. 139 ($ste7^-$). Therefore, the ste7 gene has been identified to code for a fucosyltransferase, which plays an essential role in the formation of repeating sugars units during Ebosin biosynthesis.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 제4회 추계심포지움
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• pp.65-73
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• 1996

LPS/LOS, the compound found only in gram-negative bacterial outer membrane, plays important roles in bacterial maintenance as well as its pathogenesis. We isolated and characterized several genes required for NTHi 2019 LOS biosynthesis, which encode enzymes required for sugar substrate synthesis or the transfer of substrates to receptor molecules. The htrB gene, however, appears to have more complex role. It has acryltransferase activity as well as various other activity, which may control regulation of LOS biosynthesis as well as its pathogenicity. Evidences supporting the latter come from the observations that the lipid A of the B29 induced significantly less TNF ${\alpha}$ from macrophages than that of the wild type LOS (unpublished data). H. influenzae A2-htrB mutant strain was also significantly less invasive than the wild type strain. The structural similarities of the enterobacterial LPS and the Haemophilus LOS enabled us to isolate the NTHi 2019 genes involved in LOS biosynthesis genes by using the S. typhimurium LPS deep core mutants. While a similar approach has been used for E. coli, this technique for selection of an LPS phenotype has not been applied to nonenterobacterial species. The difficulties inherent in the molecular manipulation of organism such as Neisseria and Haemophilus species make this approach particularly attractive in the identification and cloning LOS genes. Studies on genetic features of LPS/LOS biosynthesis would be useful for understanding bacterial pathogenesis as well as for developing vaccines for these gram-negative pathogenic bacteria.

• Journal of Ginseng Research
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• 제16권3호
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• pp.222-227
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• 1992

Unlike carbohydrats and fats, alcohol is essentially foreign to the body and it is known that the body get rid of it by oxidizing alcohol maily in the liver. Acetaldehyde is produced during ethanol metabolism and is known to be oxidized mainly by aldehyde dehydrogenase (ALDH). ALDH activity was found mainly in the mitochondrial fraction but a significant ALDH activity was also present in microsomal and cytosol fraction. Wistar rats (150~200 g, male) were given freely with 12% ethanol (Control) and/or 12% ethanol containing 0.1% ginseng saponins (Test) instead of water for 6 days and the liver was analyzed. ALDH activities of both control and test group were lower than that of normal group but test AkDH was less inhibited than control. ADH activies of both control and test were slightly higher than that of normal group but our previous data showed that it became gradually steady after prolonged ethanol feeding. MEOS activities of both control and test group were much higher than that of normal group. MEOS enzymes are inducible but the activity of test group was greatly higher than that of control. Ethanol containing [1-i4C] ethanol (5 $\mu$Ci) was injected to the above three groups and 30 min later, the distribution of radioactivity of hepatic lipids was investigated. Radioactivities of hepatic lipids of both control and test group were higher than that of normal group, however, that of test group was much lower than that of control. Analysis of individual lipids showed that phospholipid biosynthesis was significantly impaired and fatty acid and triglycerides biosynthesis were greatly stimulated. However, it was realized that the saponin prevented phospholipid biosynthesis depression and the increase of triglyceride biosynthesis considerably. It seemed that the saponin might stimulate ADH, ALDH and MEOS and the acetaldehyde formed would be removed faster. The excess hydrogen can be shunt more quickly into lipid biosynthesis. Electron microscopic observation showed that the hepatic cell of control group was si gnificantly damaged. Mitochondria were swollen and rough endoplasmic reticulum were dilated, however, hepatocytes of test group were not damaged.

• 한국동물위생학회지
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• 제44권4호
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• pp.195-207
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• 2021

Species A rotaviruses (RVAs) replicate and assemble their immature particles within electron dense compartments known as viroplasms, where lipid droplets (LDs) interact with the viroplasm and facilitate viral replication. Despite the importance of LD formation in the life cycle of RVAs, the upstream molecules modulating LD formation remain unclear. This study aimed to find out the role of sterol regulatory element-binding proteins (SREBPs) in reprogramming of LD formation after RVA infection. Here, we demonstrate that RVA infection reprograms the sterol regulatory element-binding proteins (SREBPs)-dependent lipogenic pathways in virus-infected cells, and that both SREBP-1 and -2 transactivated genes, which are involved in fatty acid and cholesterol biosynthesis, are essential for LD formation. Our results showed that pharmacological inhibition of SREBPs using AM580 and betulin and inhibition of their downstream cholesterol biosynthesis (simvastatin for HMG-CoA reductase) and fatty acid enzymes (TOFA) negatively modulated the intracellular triacylglycerides and cholesterol levels and their resulting LD and viroplasm formations. Interestingly, pharmacological inhibition of SREBPs significantly reduced RVA protein synthesis, genome replication and progeny production. This study identified SREBPs-mediated lipogenic reprogramming in RVA-infected host cells, which facilitates virus replication through LD formation and its interaction with viroplasms, suggesting that SREBPs can be a potential target for the development of efficient and affordable therapeutics against RVA infection.

• 한국환경보건학회지
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• 제20권2호
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• pp.80-89
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• 1994

The effects of amphotericin B (150 $\mu$g/ml) and cycloheximide (10 $\mu$g/ml) on the biosynthesis of phospholipid and their fatty acid composition in chloroplast isolated from Chlorella were analyzed to compare with control. The levels of total lipid, phosphatidylethanolamine (PE), and phosphatidylcholine (PC) in the group treated with antibiotics were decreased. However, the biosynthesis of phosphatidylinositol (PI) was not affected by antibiotics. The major fatty acid in chloroplast envelope was linolenic acid (27.71%) in control and stearic acid (21.59%) in the group treated with amphotericin B. It was showed that the group treated with cycloheximide contained more unsaturated fatty acid than the control.

• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.658-661
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• 2015

Genes encoding enzymes with sequence similarity to hopanoids biosynthetic enzymes of other organisms were cloned from the hopanoid (hop) gene cluster of Streptomyces peucetius ATCC 27952 and transformed into Streptomyces venezuelae YJ028. The cloned fragments contained four genes, all transcribed in one direction. These genes encode polypeptides that resemble polyprenyl diphosphate synthase (hopD), squalene-phytoene synthases (hopAB), and squalene-hopene cyclase (hopE). These enzymes are sufficient for the formation of the pentacyclic triterpenoid lipid, hopene. The formation of hopene was verified by gas chromatography/mass spectrometry.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1890-1894
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• 2008

Apoemulsan is a biopolymer with potent emulsification activity, produced by Acinetobacter venetian us RAG-1 (RAG-1). The wee gene cluster is responsible for apoemulsan biosynthesis. The analysis of (i) a putative polysaccharide copolymerase mutant (${\Delta}wzc$), (ii) a putative polymerase mutant (${\Delta}wzy$), and (iii) an apoemulsan-deficient variant (${\Delta}2$) indicated that the wee gene cluster controls the synthesis of two polysaccharides: high molecular weight (HMW) and low molecular weight (LMW). LMW polysaccharide of wee origin was present in LPS isolated from RAG-1 cells, suggesting a link to the Lipid A-core of LPS molecules. SDS-PAGE analysis indicated that apoemulsan is copurified with LPS polysaccharide, with implications in the emulsification activity of RAG-1 polymer.

• 한국작물학회지
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• 제49권2호
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• pp.116-120
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• 2004

In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.

• Childhood Kidney Diseases
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• 제26권1호
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• pp.25-30
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• 2022

Dyslipidemia in nephrotic syndrome (NS) is often characterized by marked increases in the levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, and other lipoproteins, such as very low-density lipoprotein, intermediate-density lipoprotein, and lipoprotein(a). It has been suggested that impaired catabolism of lipoproteins and cholesterol is mainly due to decreased lipoprotein lipase and hepatic lipase activity, and increased biosynthesis of lipoproteins in the liver. The management strategies for dyslipidemia in patients with NS consist of lifestyle modification, lipid-lowering agents represented by statins, second-line agents such as fibrates and bile acid sequestrants, and lipid apheresis. Compared with dyslipidemia in adult NS patients, whose risks of atherosclerotic disease and progressive renal injury are considered high, clinical data on dyslipidemia in pediatric NS patients are limited. Therefore, it is necessary to pay more attention to the evaluation and management of dyslipidemia in pediatric patients with NS in clinical practice.