• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.52-57
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• 2021

Fumonisin B1 (FB1) structurally resembles sphingolipids and interferes with their metabolism leading to sphingolipid dysregulation. We questioned if FB1 could exacerbate liver or kidney toxicities in glutathione peroxidase 1 (Gpx1) and catalase (Cat) knockout mice. While higher serum levels of thiobarbituric acid reactive substances (TBARS) and sphinganine (Sa) were measured in Gpx1/Cat knockout mice (Gpx1/Cat KO) than wild type mice after 5 days of FB1 treatment, serum levels of alanine aminotransferase (ALT), sphingosine-1 phosphate (So-1-P), and sphinganine-1 phosphate (Sa-1-P) were found to be relatively low. Although Sa was highly elevated in Gpx1/Cat KO mice and wild mice, lower levels of So and Sa were found in both the kidney and liver tissues of Gpx/Cat KO mice than wild type mice after FB1 treatment. Paradoxically, FB1-induced cellular apoptosis and necrosis were hastened under oxidative stress in Gpx1/Cat KO mice.

• Biomolecules & Therapeutics
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• v.29 no.4
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• pp.373-383
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• 2021

Atherosclerosis is the deposition of plaque in the main arteries. It is an inflammatory condition involving the accumulation of macrophages and various lipids (low-density lipoprotein [LDL] cholesterol, ceramide, S1P). Moreover, endothelial cells, macrophages, leukocytes, and smooth muscle cells are the major players in the atherogenic process. Sphingolipids are now emerging as important regulators in various pathophysiological processes, including the atherogenic process. Various sphingolipids exist, such as the ceramides, ceramide-1-phosphate, sphingosine, sphinganine, sphingosine-1-phosphate (S1P), sphingomyelin, and hundreds of glycosphingolipids. Among these, ceramides, glycosphingolipids, and S1P play important roles in the atherogenic processes. The atherosclerotic plaque consists of higher amounts of ceramide, glycosphingolipids, and sphingomyelin. The inhibition of the de novo ceramide biosynthesis reduces the development of atherosclerosis. S1P regulates atherogenesis via binding to the S1P receptor (S1PR). Among the five S1PRs (S1PR1-5), S1PR1 and S1PR3 mainly exert anti-atherosclerotic properties. This review mainly focuses on the effects of ceramide and S1P via the S1PR in the development of atherosclerosis. Moreover, it discusses the recent findings and potential therapeutic implications in atherosclerosis.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1996.12a
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• pp.25-41
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• 1996

KWON, O. S. SCHMUED, L. C. and LSIKKER, W. JR. Neurotoxiciligy. objectives of this study were to test the hypothesis that fumonisin $B_1$ ($FB_1$) alters sphinganine (Sa) levels and myelin synthesis in the central nervous system of developing rats. $FB_1$ (subcutaneous, 0. 4 or 0. 8 mg/kg/day) from postnatal days (PND) 3 to PND 12 resulted in a significantly increased in the brain of rats given 0. 8 mg $FB_1$/kg/day. To confirm the effect of limited nutrition on changes in the Sa levels and myelinogenesis, rats given 0.8mg $FB_1$/kg/day or treated by limited nutrition (temporary removal from dam during postnatal period) were compared to those in saline controls. Sa levels and Sa/So ratios were compared to those in saline in the 0.8 $FB_1$-treated, 3'-phosphohydrolase (CNP) activities were decreased significantly in both nutritionally limited and $FB_1$-exposed rats. These data indicate that sphingolipid metabolism in the central nervous system of develiping rats is vulnerable to $FB_1$ exposure. The hypomyelination associated with $FB_1$-treatment may be mediated by limited nutrition.

• Journal of Korean Neurosurgical Society
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• v.66 no.2
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• pp.133-143
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• 2023

Objective : The types and functions of lipids involved in glioblastoma (GB) are not well known. Lipidomics is a new field that examines cellular lipids on a large scale and novel aplication of lipidomics in the biomedical sciences have emerged. This study aimed to investigate the potential of blood lipids for use as biomarkers for the diagnosis of GB via untargated lipidomic approach. Gaining a deeper understanding of lipid metabolism in patients with GB can contribute to the early diagnosis with GB patiens and also development of novel and better therapeutic options. Methods : This study was performed using blood samples collected from 14 patients (eight females and six males) and 14 controls (eight females and six males). Lipids were extracted from blood samples and quantified using phosphorus assay. Lipid profiles of between patients with GB and controls were compared via an untargeted lipidomics approach using 6530 Accurate-Mass Q-TOF LC/MS mass spectrometer. Results : According to the results obtained using the untargeted lipidomics approach, differentially regulated lipid species, including fatty acid (FA), glycerolipid (GL), glycerophospholipid (PG), saccharolipid (SL), sphingolipid (SP), and sterol lipid (ST) were identified between in patients with GB and controls. Conclusion : Differentially regulated lipids were identified in patients with GB, and these lipid species were predicted as potential biomarkers for diagnosis of GB.

• Korean Journal of Agricultural Science
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• v.39 no.3
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• pp.349-355
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• 2012

Thyroglobulin (TG) gene was known to be regulated fat cell growth and differentiation and the endothelial differentiation sphingolipid G-protein-coupled receptor 1 (EDG1) gene involves blood vessel formation and known to be affecting carcass traits in beef cattle. The aim of this study was to identify the single nucleotide polymorphisms (SNPs) in both TG and EDG1 genes and to analyze the association with carcass traits in Korean cattle (Hanwoo). The T354C SNP in TG gene located at the 3' flanking region and c.-312A>G SNP located at 3'-UTR of EDG1 gene were used for genotyping the animals using PCR-RFLP method. Three genotypes were identified in T354C SNP in TG gene and only two AA and AG genotypes were observed for the c.-312A>G SNP in EDG1 gene. The results indicated that T354C SNP in TG gene was not significantly associated with carcass traits. However, the c.-312A>G SNP in EDG1 gene had significant effects on backfat thickness (BF) and yield index (YI). These results may provide valuable information for further candidate gene studies affecting carcass traits in Korean cattle and may use as marker assisted selection for improving the quality of meat in Hanwoo.

• BMB Reports
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• v.42 no.10
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• pp.685-690
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• 2009

Angiogenesis is essential for tumor growth and vascular endothelial cell growth factor (VEGF) plays a key role in this process. Conversely, sphingosine 1-phosphate (S1P) is a biologically active sphingolipid known to play a key role in cancer progression by regulating endothelial cell proliferation and migration. In this study, the authors found that S1P increases the level of VEGF mRNA in human umbilical vein endothelial cells (HUVECs) and immortalized HUVECs (iHUVECs). Additionally, S1P was found to increase VEGF promoter activity in MS-1 mouse pancreatic islet endothelial cells. Furthermore, a pharmacological inhibitory study revealed that $G_{\alpha i/o}$-mediated phospholipase C, Akt, Erk, and p38 MAPK signaling are involved in this S1P-induced expression of VEGF. A component of AP1 transcription factor is important for S1P-induced VEGF expression. Taken together, these findings suggest that S1P enhances endothelial cell proliferation and migrat ion by upregulating the expression of VEGF mRNA.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.70-70
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• 2002

Sphingosine-1-phosphate(S1P) is one of the sphingolipid metabolites which affect a variety of cellular processes including the proliferation, differentiation, growth, survival, migration and gene expression. The present study was undertaken to investigate the effect of SIP on nuclear maturation of porcine oocytes. In vitro maturation frequency of porcine oocytes were compared in three different media; group Ⅰ: NCSU23＋0.1% PVA, group Ⅱ: NCSU23＋10% PFF(porcine follicular fluid), and group Ⅲ: NCSU23＋10% PFF＋10 ng/㎖ EGF＋2.5 mM β-mercaptoethanol. Each group containing 0.1 ㎎/㎖ cysteine was divided into 4 sub-groups of SIP concentration(0, 50, 500 and 5000nM). Porcine oocytes were incubated in each maturation medium supplemented with hormones(10 IU/㎖ PMSG and 10 IU/㎖ hCG) for 22h and then further cultured in the same medium without the hormones for 22h. After completion of in vitro maturation, the oocytes were fixed and stained to examine nuclear maturation by using a rapid stain method. In the group Ⅰ, the proportions of metaphase Ⅱ stage among oocytes cultured in 0nM(control), 50 nM, 500nM and 5000nM S1P were 45.5%, 66.7%, 56.6% and 48.7%, respectively. (omitted)

• Molecules and Cells
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• v.37 no.2
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• pp.161-171
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• 2014

In several lysosomal storage disorders, including Niemann-Pick disease Type C (NP-C), sphingolipids, including glycosphingolipids, particularly gangliosides, are the predominant storage materials in the brain, raising the possibility that accumulation of these lipids may be involved in the NP-C neurodegenerative process. However, correlation of these accumulations and NP-C neuropathology has not been fully characterized. Here we derived NP-C mice with complete and partial deletion of the Siat9 (encoding GM3 synthase) gene in order to investigate the role of ganglioside in NP-C pathogenesis. According to our results, NP-C mice with homozygotic deletion of GM3 synthase exhibited an enhanced neuropathological phenotype and died significantly earlier than NP-C mice. Notably, in contrast to complete depletion, NP-C mice with partial deletion of the GM3 synthase gene showed ameliorated NP-C neuropathology, including motor disability, demyelination, and abnormal accumulation of cholesterol and sphingolipids. These findings indicate the crucial role of GM3 synthesis in the NP-C phenotype and progression of CNS pathologic abnormality, suggesting that well-controlled inhibition of GM3 synthesis could be used as a therapeutic strategy.

• Molecular & Cellular Toxicology
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• v.2 no.2
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• pp.81-88
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• 2006

Sphingolipid metabolites regulate many aspects of cell proliferation, differentiation, and apoptosis. In the present study, we have assessed the effects of the novel phytosphingosine derivative, N-acetylphytospingosine (NAPS), on the depigmentation of murine B16F10 melanoma cells, and have also attempted to identify the possible signaling pathway involved, in comparison with $C_{2}-ceramide$. NAPS and $C_{2}-ceramide$ both inhibited the growth of the B16F10 cells in a dose-dependent manner. Melanin content and tyrosinase activity were significantly reduced in response to treatment with NAPS and $C_{2}-ceramide$ at concentrations in a range between $1-5\;{\mu}M$. However, the levels of tyrosinase mRNA, as well as the levels of tyrosinase related protein-1 (TRP-1) and tyrosinase related protein-2 (TRP-2) genes and the level of tyrosinase protein remained unaffected by treatment with either NAPS or $C_{2}-ceramide$. We also attempted to determine the signaling pathway exploited by NAPS and $C_{2}-ceramide$. Interestingly, the phosphorylation of Akt/PKB at serine 473 by NAPS was reduced at the 5 minute mark, whereas $C_{2}-ceramide$ induced the phosphorylation of Akt/PKB at serine 473. Finally, Akt/PKB activity in the NAPS-treated cells was elevated in comparison with the untreated cells. LY294002, a specific PI3-K inhibitor which is located upstream of Akt/PKB, inhibited the phosphorylation of Akt/PKB, but induced an increase in melanin synthesis. These results suggest that the activation of Akt/PKB at serine 473 is related with the suppression of melanin production in the B16F10 mouse melanoma cells. Therefore, the mechanisms exploited by NAPS and $C_{2}-ceramide$ responsible for the depigmentation of B16F10 cells were concluded to involve the inhibition of melanosomal tyrosinase activity.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.311-318
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• 2005

Oxidative stress has been reported to elevate ceramide level during cell death. The purpose of the present study was to modulate cell death in relation to cellular glutathione (GSH) level and GST (glutathione S-transferase) expression by regulating the sphingolipid metabolism. LLC­PK1 cells were treated with H$_2$O$_2$ in the absence of serum to induce cell death. Subsequent to exposure to H$_2$O$_2$, LLC-PK1 cells were treated with desipramine, sphingomyelinase inhibitor, and N-acetylcysteine (NAC), GSH substrate. Based on comparative visual observation with H202-treated control cells, it was observed that 0.5 $\mu$M of desipramine and 25 $\mu$M of NAC exhibited about 90 and $95\%$ of cytoprotection, respectively, against H$_2$O$_2$-induced cell death. Desipramine and NAC lowered the release of LDH activity by 36 and $3\%$ respectively, when compared to $71\%$ in H$_2$O$_2$-exposed cells. Cellular glutathione level in 500 $\mu$M H202-treated cells was reduced to 890 pmol as compared to control level of 1198 pmol per mg protein. GST P1-1 expression was decreased in H$_2$O$_2$-treated cells compared to healthy normal cells. In conclusion, it has been inferred that H$_2$O$_2$-induced cell death is closely related to cellular GSH level and GST P1-1 expression in LLC-PK1 cells and occurs via ceramide elevation by sphingomyelinase activation.