• Title/Summary/Keyword: molecular functions

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Synthesis of Reconstituted High Density Lipoprotein (rHDL) Containing apoA-I and apoC-III: the Functional Role of apoC-III in rHDL

  • Cho, Kyung-Hyun
    • Molecules and Cells
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    • v.27 no.3
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    • pp.291-297
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    • 2009
  • Apolipoprotein (apo) C-III is a marker protein of triacylglycerol (TG)-rich lipoproteins and high-density lipoproteins (HDL), and has been proposed as a risk factor of coronary heart disease. To compare the physiologic role of reconstituted HDL (rHDL) with or without apoC-III, we synthesized rHDL with molar ratios of apoA-I:apoC-III of 1:0, 1:0.5, 1:1, and 1:2. Increasing the apoC-III content in rHDL produced smaller rHDL particles with a lower number of apoA-I molecules. Furthermore, increasing the molar ratio of apoC-III in rHDL enhanced the surfactant-like properties and the ability to lyse dimyristoyl phosphatidylcholine. Furthermore, rHDL containing apoC-III was found to be more resistant to particle rearrangement in the presence of low-density lipoprotein (LDL) than rHDL that contained apoA-I alone. In addition, the lecithin:cholesterol acyltransferase (LCAT) activation ability was reduced as the apoC-III content of the rHDL increased; however, the CE transfer ability was not decreased by the increase of apoC-III. Finally, rHDL containing apoC-III aggravated the production of MDA in cell culture media, which led to increased cellular uptake of LDL. Thus, the addition of apoC-III to rHDL induced changes in the structural and functional properties of the rHDL, especially in particle size and rearrangement and LCAT activation. These alterations may lead to beneficial functions of HDL, which is involved in anti-atherogenic properties in the circulation.

Rnf152 Is Essential for NeuroD Expression and Delta-Notch Signaling in the Zebrafish Embryos

  • Kumar, Ajeet;Huh, Tae-Lin;Choe, Joonho;Rhee, Myungchull
    • Molecules and Cells
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    • v.40 no.12
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    • pp.945-953
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    • 2017
  • We report the biological functions of a zebrafish homologue of RING-finger protein 152 (rnf152) during embryogenesis. rnf152 was initially identified as a brain-enriched E3 ligase involved in early embryogenesis of zebrafish. Expression of rnf152 was ubiquitous in the brain at 24 hpf but restricted to the eyes, midbrain-hindbrain boundary (MHB), and rhombomeres at 48 hpf. Knockdown of rnf152 in zebrafish embryos caused defects in the eyes, MHB, and rhombomeres (r1-7) at 24 hpf. These defects in rnf152-deficient embryos were analyzed by whole-mount in situ hybridization (WISH) using neuroD, deltaD, notch1a, and notch3 probes. NeuroD expression was abolished in the marginal zone, outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL) of the eyes at 27 hpf. Furthermore, deltaD and notch1a expression was remarkably reduced in the ONL, INL, subpallium, tectum, cerebellum, and rhombomeres (r1-7) at 24 hpf, whereas notch3 expression was reduced in the tectum, cerebellum, and rhombomeres at 24 hpf. Finally, we confirmed that expression of Notch target genes, her4 and ascl1a, also decreased significantly in these areas at 24 hpf. Thus, we propose that Rnf152 is essential for development of the eyes, midbrain and hindbrain, and that Delta-Notch signaling is involved.

Effects of Gamgung-tang Gamibang on 3,5,3-triiodothyronine-induced Hyperthyroidism in rats (감궁탕 가미방이 갑상샘기능장애에 미치는 효과)

  • Choi Ho Seung;Kim Young Mok;Lim Jong Kook;Shon Yun Hee;Nam Kyung Soo;Kim Cheol Ho;Jeon Byung Hun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.3
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    • pp.648-655
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    • 2003
  • In this study, the effects of Gamgung-tang gamibang on the hyperthyroidism induced by the intraperitoneal injection of 3,5,3-triiodothyronine was examined by the measurement of physical changes, body weight, the volume of food intake and rectal temperature, and heart weight, heart beat, blood pressure with contrast to propranolol, one of beta-blocking agents. the obtained results were as follows. The Gamgung-tang gamibang extract showed to inhibit the decrease of body weight and rectal temperature, and decrease the food intake, so the inhibitory effects of Gamgung-tang gamibang extract on the experimental hyperthyroidism were exhibited. The Gamgung-tang gamibang extract showed the inhibitory effects on the circulatory functions changed and enhanced by the experimental induced hyperthyroidism, the action of Gamgung-tang gamibang extract was less effective than the propranolol of D-CONT group. The Gamgung-tang gamibang extract showed significant effects to inhibit the concentration of serum thyroid houmone, more effective than the propranolol, beta-blocking agents. The Gamgung-tang gamibang extract showed the effective inhibitory reaction on the biochemical changes in serum, cholesterol, ketone bodies, free fatty acid, glucose in hyperthyroid rats induced by 3,5,3-triiodothyronine.

Expression of Exogenous Human Hepatic Nuclear Factor-$1{\alpha}$ by a Lentiviral Vector and Its Interactions with Plasmodium falciparum Subtilisin-Like Protease 2

  • Liao, Shunyao;Liu, Yunqiang;Zheng, Bing;Cho, Pyo-Yun;Song, Hyun-Ok;Lee, Yun-Seok;Jung, Suk-Yul;Park, Hyun
    • Parasites, Hosts and Diseases
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    • v.49 no.4
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    • pp.431-436
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    • 2011
  • The onset, severity, and ultimate outcome of malaria infection are influenced by parasite-expressed virulence factors as well as by individual host responses to these determinants. In both humans and mice, liver injury follows parasite entry, persisting to the erythrocytic stage in the case of infection with the fatal strain of Plasmodium falciparum. Hepatic nuclear factor (HNF)-$1{\alpha}$ is a master regulator of not only the liver damage and adaptive responses but also diverse metabolic functions. In this study, we analyzed the expression of host HNF-$1{\alpha}$ in relation to malaria infection and evaluated its interaction with the 5'-untranslated region of subtilisin-like protease 2 (subtilase, Sub2). Recombinant human HNF-$1{\alpha}$ expressed by a lentiviral vector (LV HNF-$1{\alpha}$) was introduced into mice. Interestingly, differences in the activity of the 5'-untranslated region of the Pf-Sub2 promoter were detected in 293T cells, and LV HNF-$1{\alpha}$ was observed to influence promoter activity, suggesting that host HNF-$1{\alpha}$ interacts with the Sub2 gene.

Effect of Dietary Folate on Hyperhomocysteinemia and Cellular Toxicity Induced Alcohol Administration in Rat Liver

  • Kim, Chung-Hyeon;Kim, Ki-Nam;Kim, Yeon-Soo;Chang, Nam-Soo
    • Molecular & Cellular Toxicology
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    • v.1 no.2
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    • pp.137-141
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    • 2005
  • The critical role of folate in the remethylation pathway for methionine synthesis from homocysteine has been well documented. Hyperhomocysteinemia resulting from inadequate folate nutrition has been implicated in increased incidence of macrovascular diseases, colorectal cancer, neural tube defects, etc. Chronic exposure to ethanol impairs folate nutrition and one-carbon metabolism in the liver, which often results in fatty liver due to a defective remetylation process. This study was carried out to investigate the chronic effects of moderate levels of alcohol and dietary folate on plasma homocysteine levels, and on histopathology and biochemical functions of the liver. Rats were raised on experimental diets with three levels of folate (0, 2, 8 mg/kg diet), and 50% ethanol (1.8 ml/kg body weight) was administered intragastically by intubation tubes three times a week for 10 weeks. Plasma homocysteine concentrations were found to be significantly influenced by dietary folate intake and alcohol administration. Among all treatment groups, plasma homocysteine levels were the highest in the animals receiving a combined treatment of folate deficient diet and alcohol administration. Plasma homocysteine concentrations were negatively correlated with folate concentration in the plasma (p<0.01) and liver (p<0.05). Among alcohol treated rats, increase in plasma homocysteine values due to macrovascular and microvascular fatty changes and spotted necrosis were observed more frequently in folate-deficient animals diet than those on folate-adequate and folate supplemented diets in alcohol-treated rats. These results indicate that folate supplementation above the recommended level might be beneficial in the prevention of alcohol-related hyperhomocysteinemia and abnormal histologic changes in the liver.

Nitric Oxide Dependency in Inflammatory Response-related Gene Transcripts Expressed in Lipopolysaccharide-treated RAW 264.7 Cells

  • Pie, Jae-Eun;Yi, Hyeon-Gyu
    • Molecular & Cellular Toxicology
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    • v.5 no.4
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    • pp.354-363
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    • 2009
  • Cytotoxic Nitric oxide (NO) overproduced by inducible NO Synthase (iNOS or NOS2), which was induced in inflammatory reactions and immune responses directly or indirectly affects the functions as host defense and can cause normal tissue damage. Microarray analysis was performed to identify gene profiles of both NO-dependent and -independent transcripts in RAW 264.7 macrophages that use selective NOS2 inhibitors aminoguanidine ($100\;{\mu}M$) and L-canavanine (1 mM). A total of 3,297 genes were identified that were up- or down-regulated significantly over 2-fold in lipopolysaccharide (LPS)-treated macrophages. NO-dependency was determined in the expressed total gene profiles and also within inflammatory conditions-related functional categories. Out of all the gene profiles, 1711 genes affected NO-dependently and -independently in 567 genes. In the categories of inflammatory conditions, transcripts of 16 genes (Pomp, C8a, Ifih1, Irak1, Txnrd1, Ptafr, Scube1, Cd8a, Gpx4, Ltb, Fasl, Igk-V21-9, Vac14, Mbl1, C1r and Tlr6) and 29 geneas (IL-1beta, Mpa2l, IFN activated genes and Chemokine ligands) affected NO-dependently and -independently, respectively. This NO dependency can be applied to inflammatory reaction-related functional classifications, such as cell migration, chemotaxis, cytokine, Jak/STAT signaling pathway, and MAPK signaling pathway. Our results suggest that LPS-induced gene transcripts in inflammation or infection can be classified into physiological and toxic effects by their dependency on the NOS2-mediated NO release.

Long-Term Expression of von Willebrand Factor by a VSV-G Pseudotyped Lentivirus Enhances the Functional Activity of Secreted B-Domain-deleted Coagulation Factor VIII

  • Park, Sang Won;Choi, Sang-Yun
    • Molecules and Cells
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    • v.24 no.1
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    • pp.125-131
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    • 2007
  • von Willebrand factor (vWF) is a multimeric glycoprotein which functions within the coagulation system. It colocalizes with factor VIII (FVIII) by non-covalent interaction and alters its intracellular trafficking. vWF is also instrumental in maintaining the stability of secreted FVIII. The principal objective of this study was to generate a lentivirus-based vWF expression vector for gene therapy of hemophilia A. We inserted a vWF of 8.8 Kb into a lentiviral vector thereby producing VSV-G-pseudotyped vEx52. However, its titer was quite low, presumably because the length of vWF gene exceeds the size limit of the lentiviral vector. In order to overcome the low-titer, we concentrated the vEx52 and thus increased the efficiency of transduction approximately 6-fold with $1/100^{th}$ of the volume. However, as concentration requires an additional laborious step, we attempted to enhance the transduction efficiency by deleting exons 24-46 and 29-46 in pRex52 to construct pRex23 and pRex28, and in pvEx52, yielding pvEx23 and pvEx28, respectively. The transfected pRex52 had a profound effect on the activity of secreted FVIII, and this activity declined as domains of vWF were deleted. However, when the domain-deleted vWF-lentiviruses were transduced into K562 cells, the vEx28 increased the activity of the secreted FVIII compared to what was observed with vEx52. This result is probably due to higher efficiencies of transduction and expression while retaining the essential domains required for proper interaction with FVIII.

Rosmarinic Acid Down-Regulates the LPS-Induced Production of Monocyte Chemoattractant Protein-1 (MCP-1) and Macrophage Inflammatory Protein-1α (MIP-1α) via the MAPK Pathway in Bone-Marrow Derived Dendritic Cells

  • Kim, Hyung Keun;Lee, Jae Joon;Lee, Jun Sik;Park, Yeong-Min;Yoon, Taek Rim
    • Molecules and Cells
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    • v.26 no.6
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    • pp.583-589
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    • 2008
  • In the present study, we investigated whether rosmarinic acid, which has been suggested to exhibit anti-inflammatory properties, can suppress the expressions of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-$1{\alpha}$ ($MIP-1{\alpha}$) via the MAPK pathway in LPS-stimulated bone marrow-derived dendritic cells (BMDCs) in the presence of GM-CSF and IL-4 in media. The effects of rosmarinic acid were investigated in BMDCs with respect to the following; cytotoxicity, surface molecule expression, dextran-FITC uptake, cell migration, chemokine gene expression, and the MAPK signaling pathway. Rosmarinic acid was found to significantly inhibit the expressions of CD80, CD86, MHC class I, and MHC class II in LPS-stimulated mature BMDCs, and rosmarinic acid-treated BMDCs were found to be highly efficient with regards to antigen capture via mannose receptor-mediated endocytosis. In addition, rosmarinic acid reduced cell migration by inducing the expression of a specific chemokine receptor on LPS-induced mature BMDCs. Rosmarinic acid also significantly reduced the expressions of MCP-1 and $MIP-1{\alpha}$ induced by LPS in BMDCs and inhibited LPS-induced activation of MAPK and the nuclear translocation of $NF-{\kappa}B$. These findings broaden current perspectives concerning our understanding of the immunopharmacological functions of rosmarinic acid, and have ramifications that concern the development of therapeutic drugs for the treatment of DC-related acute and chronic diseases.

Glyceraldehyde-3-Phosphate, a Glycolytic Intermediate, Plays a Key Role in Controlling Cell Fate Via Inhibition of Caspase Activity

  • Jang, Mi;Kang, Hyo Jin;Lee, Sun Young;Chung, Sang J.;Kang, Sunghyun;Chi, Seung Wook;Cho, Sayeon;Lee, Sang Chul;Lee, Chong-Kil;Park, Byoung Chul;Bae, Kwang-Hee;Park, Sung Goo
    • Molecules and Cells
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    • v.28 no.6
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    • pp.559-563
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    • 2009
  • Glyceraldehyde-3-phosphate is a key intermediate in several central metabolic pathways of all organisms. Aldolase and glyceraldehyde-3-phosphate dehydrogenase are involved in the production or elimination of glyceraldehyde-3-phosphate during glycolysis or gluconeogenesis, and are differentially expressed under various physiological conditions, including cancer, hypoxia, and apoptosis. In this study, we examine the effects of glyceraldehyde-3-phosphate on cell survival and apoptosis. Overexpression of aldolase protected cells against apoptosis, and addition of glyceraldehyde-3-phosphate to cells delayed apoptosis. Additionally, delayed apoptotic phenomena were observed when glyceraldehyde-3-phosphate was added to a cell-free system, in which artificial apoptotic process was induced by adding dATP and cytochrome c. Surprisingly, glyceraldehyde-3-phosphate directly suppressed caspase-3 activity in a reversible noncompetitive mode, preventing caspase-dependent proteolysis. Based on these results, we suggest that glyceraldehyde-3-phosphate, a key molecule in several central metabolic pathways, functions as a molecule switch between cell survival and apoptosis.

Visualization of Multicolored in vivo Organelle Markers for Co-Localization Studies in Oryza sativa

  • Dangol, Sarmina;Singh, Raksha;Chen, Yafei;Jwa, Nam-Soo
    • Molecules and Cells
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    • v.40 no.11
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    • pp.828-836
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    • 2017
  • Eukaryotic cells consist of a complex network of thousands of proteins present in different organelles where organelle-specific cellular processes occur. Identification of the subcellular localization of a protein is important for understanding its potential biochemical functions. In the post-genomic era, localization of unknown proteins is achieved using multiple tools including a fluorescent-tagged protein approach. Several fluorescent-tagged protein organelle markers have been introduced into dicot plants, but its use is still limited in monocot plants. Here, we generated a set of multicolored organelle markers (fluorescent-tagged proteins) based on well-established targeting sequences. We used a series of pGWBs binary vectors to ameliorate localization and co-localization experiments using monocot plants. We constructed different fluorescent-tagged markers to visualize rice cell organelles, i.e., nucleus, plastids, mitochondria, peroxisomes, golgi body, endoplasmic reticulum, plasma membrane, and tonoplast, with four different fluorescent proteins (FPs) (G3GFP, mRFP, YFP, and CFP). Visualization of FP-tagged markers in their respective compartments has been reported for dicot and monocot plants. The comparative localization of the nucleus marker with a nucleus localizing sequence, and the similar, characteristic morphology of mCherry-tagged Arabidopsis organelle markers and our generated organelle markers in onion cells, provide further evidence for the correct subcellular localization of the Oryza sativa (rice) organelle marker. The set of eight different rice organelle markers with four different FPs provides a valuable resource for determining the subcellular localization of newly identified proteins, conducting co-localization assays, and generating stable transgenic localization in monocot plants.