Ko Y.-G.,South Korean National Institute of Animal Science |
Park H.J.,Gyongsang National University |
Yun J.,Ajou University |
Koh P.-O.,Gyongsang National University |
And 6 more authors.
Placenta | Year: 2010
To understand the tissue-specific expression of the rat placental lactogen-I variant (rPL-Iv) gene, we investigated the methylation pattern of the 5′-flanking region of this gene in various rat tissues. We report that the 5′-flanking region of the rPL-Iv gene was hypomethylated in placenta that expressed the gene and hypermethylated in those tissues that did not express the gene. Moreover, the intron region of the rPL-Iv gene was hypomethylated in the placenta, but hypermethylated in the liver, kidney and pituitary. Although there are 5 CpG sites and the density of CpG dinucleotide is lower within 2 kb of the rPL-Iv 5′-flanking region, the methylated promoter reporter gene produced strong repression in the transcriptional activity of the gene. In addition, the 5′-flanking and intron regions of the rPL-Iv gene were hypomethylated on day 12 of gestation, and the methylation pattern in the placenta remained unchanged from mid-pregnancy until term. The entire genomic region of the rPL-Iv gene might be hypermethylated in tissues other than the placenta, within which its methylated status repress expression of the placenta-specific rPL-Iv gene. Interestingly, the methylation status of the intron region of the rPL-Iv in proliferating Rcho-1 cells was changed to the unmethylated status on day 8 and 12 of differentiation of Rcho-1 cells. These results demonstrate that demethylation in the rPL-Iv upstream region was induced at an early stage of placental development, and once the 5′-flanking region of the rPL-Iv had been demethylated, its status on the rPL-Iv genomic region was continued during pregnancy. Taken together, these results suggest that DNA methylation is responsible for the silencing of tissue-specific genes in non-expressing cells, while defined combinations of trophoblast factors dictate the expression of unmethylated rPL-Iv gene in placenta trophoblast cells. © 2010 Elsevier Ltd. All rights reserved.
Radnaabazar C.,Inje University |
Park C.M.,Inje University |
Kim J.H.,Gyongsang National University |
Cha J.,Korea University |
Song Y.-S.,Inje University
Journal of Medicinal Food | Year: 2011
This study characterized the efficacy of recombinant Cheonggukjang kinase (CGK) 3-5-rich fraction as a thrombolytic agent, which we overexpressed in Bacillus licheniformis ATCC10716, a strain normally lacking fibrinolytic activity. We found that CGK3-5 is a plasmin-like protease that directly degrades fibrin clots and does not activate plasminogen during fibrin clot lysis and platelet-rich clot lysis assays. We also confirmed antiplatelet and antithrombotic activity by CGK3-5-rich fraction both in vitro and in vivo. CGK3-5-rich fraction inhibited collagen-induced platelet aggregation in platelet-rich plasma in a concentration-dependent manner. The concentration of 1.5mg/mL CGK3-5-rich fraction completely inhibited collagen-induced platelet aggregation. Furthermore, injection of CGK3-5-rich fraction into tail veins dose-dependently protected mice from death by pulmonary embolism induced by collagen and epinephrine. The survival rates were 30%, 70%, and 100%, respectively, with doses of 130mg/kg, 260mg/kg, and 520mg/kg. These findings suggest that CGK3-5 holds promise as a treatment to mitigate the potentially effects of stroke and heart failure. © Copyright 2011, Mary Ann Liebert, Inc.