Biomedical subjects

Sang-Cheol Kim

Publications and source records attributed to Sang-Cheol Kim.

3 recordsLinked to original sources

PubMed2006

SNP@Ethnos: a database of ethnically variant single-nucleotide polymorphisms.

Inherited genetic variation plays a critical but largely uncharacterized role in human differentiation. The completion of the International HapMap Project makes it possible to identify loci that may cause human differentiation. We have devised an approach to find such ethnically variant single-nucleotide polymorphisms (ESNPs) from the genotype profile of the populations included in the International HapMap database. We selected ESNPs using the nearest shrunken centroid method (NSCM), and performed multiple tests for genetic heterogeneity and frequency spectrum on genes having ESNPs. The function and disease association of the selected SNPs were also annotated. This resulted in the identification of 100 736 SNPs that appeared uniquely in each ethnic group. Of these SNPs, 1009 were within disease-associated genes, and 85 were predicted as damaging using the Sorting Intolerant From Tolerant system. This study resulted in the creation of the SNP@Ethnos database, which is designed to make this type of detailed genetic variation approach available to a wider range of researchers. SNP@Ethnos is a public database of ESNPs with annotation information that currently contains 100 736 ESNPs from 10 138 genes, and can be accessed at http://variome.net and http://bioportal.net/ or directly at http://bioportal.kobic.re.kr/SNPatETHNIC/.

Chromosome Mapping↗

PubMed2006

Roles of p38 and ERK MAP kinases in IL-8 expression in TNF-alpha- and dexamethasone-stimulated human periodontal ligament cells.

Orthodontic tooth movement is recognized as a pro-inflammatory stressor of human periodontal ligament (hPDL) cells. However, the cell-signaling pathways linking interleukin-8 (IL-8), intercellular adhesion molecule-1 (ICAM-1), pro-inflammatory cytokines, and dexamethasone in hPDL cells have not been well elucidated. In this study, we investigated the role of mitogen-activated protein (MAP) kinases in dexamethasone- and TNF-alpha-induced IL-8 and ICAM-1 expression in hPDL cells. IL-8 production was measured by enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. MAP kinase activation and IkappaB degradation were determined by Western blot analysis, and ICAM-1 expression was determined by RT-PCR and FACS analysis. TNF-alpha increased IL-8 mRNA expression and protein secretion in a dose- and time-dependent manner. Dexamethasone suppressed TNF-alpha-induced IL-8 production in a dose-dependent manner. In addition, dexamethasone inhibited TNF-alpha-induced phosphorylation of p38 MAP kinase and extracellular-regulated kinases (ERKs), IkappaB degradation, and NF-kappaB activation. Selective inhibitors for ERKs and p38 attenuated TNF-alpha-induced IL-8 and ICAM-1 expression in the presence and absence of dexamethasone, indicating that MAP kinases play a role in the response of hDPL cells to TNF-alpha. Furthermore, these results suggest that inflammatory cytokine- and dexamethasone-induced IL-8 and ICAM-1, produced via a MAP kinase pathway, may serve as an important mediator of PDL immunoregulation involved in bone remodeling during orthodontic tooth movement.

Anti-Inflammatory Agents↗

PubMed2004

The cytotoxicity of Scytosiphon lomentaria against HL-60 promyelocytic leukemia cells.

This study examined the cytotoxicity of Scytosiphon lomentaria, using various cancer cell lines. The ethyl acetate (EtOAc) fraction of this alga showed the cytotoxicity to leukemia cells, including HL-60. When HL-60 cells were treated with its EtOAc fraction, several apoptotic characteristics, such as DNA fragmentation, chromatin condensation, and an increase of the population of sub-G1 hypodiploid cells, were observed. Moreover, the EtOAc fraction decreased c-Myc expression in a dose-dependent manner. In order to understand the mechanism of apoptosis induction by S. lomentaria, we examined the changes of Bcl-2 and Bax protein expression levels. The EtOAc fraction reduced Bcl-2, an antiapoptotic protein, but increased Bax, a proapoptotic protein, in a dose-dependent manner. When we examined the activation of caspase-3, an effector of apoptosis, the expression of the active form (19 kDa) of caspase-3 increased, and the increase of their activities was demonstrated by the cleavage of poly (ADP-ribose) polymerase, a substrate of caspase-3, to 85 kDa. The results suggest that the inhibitory effect of S. lomentaria on the growth of HL-60 appears to arise from the induction of apoptosis by way of the down-regulation of Bcl-2 and the activation of caspase.

Acetates↗