• Journal of Life Science
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• v.29 no.8
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• pp.895-903
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• 2019

The aim of the present study was to improve the cell viability of human dental papilla derived single-induced pluripotent stem cells (iPSCs) using a Rho-associated protein kinase (ROCK) inhibitor, Y-27632. The iPSCs were produced using an episomal plasmid-based reprogramming method. After cell separation using trypsin, the iPSCs were treated with 0, 0.5, 1, 2.5, 5, 7.5, or $10{\mu}M$ Y-27632 for 5 d. Cell viability increased significantly following the $5{\mu}M$ Y-27632 treatment (p<0.05). When the iPSCs were exposed to medium containing $10{\mu}M$ Y-27632 for 0, 1, 2, 3, 4, and 5 d, the cell viability rate increased significantly in accordance with the cell viability rate (p<0.05). To evaluate the effect of the Y-27632 treatment on stemness characteristics, the expression of stem cell-specific transcripts and telomerase activity were investigated in the iPSCs treated with $10{\mu}M$ Y-27632 for 5 d. The expression levels of stem cell-specific transcripts, such as OCT-4, NONOG, and SOX-2, and telomerase activity were not significantly different in the iPSCs treated with $10{\mu}M$ Y-27632 as compared with those of untreated control iPSCs (p>0.05). Taken together, the results demonstrated that cell viability can be improved by treatment with the ROCK inhibitor Y-27632, without losing iPSC stemness characteristics.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.339-350
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• 2013

The decreased body, liver, kidney, spleen and testis weights of guinea pigs by TCDD (2,3,7,8-tetracholorodibenzo-${\rho}$-dioxin) treatment (TT) were statistically significantly increased after treating red ginseng saponin fraction (SF) (p>0.01). After treated with SF, the decreased hematocrits values and numbers of RBC and platelet, activity of amylase and lactate dehydrogenase, levels of uric acid, total protein and albumin by TT were increased, and the increased numbers of WBC, levels of triglyceride, total cholesterol (TC), LDL-cholesterol, HDL-cholesterol, creatinine, blood urea nitrogen, calcium and phosphorus, activities of creatinine kinase, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were decreased after treated with SF. And they all had a statistical significance (p>0.01) except for RBC, WBC, platelet, blood glucose, TC, calcium and albumin. From these results, we knew that SF mollified the acute toxicity induced by TCDD in guinea pigs.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.93-99
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• 2005

Human embryonic stem cells (hESCs) derived from the inner cell mass of blastocysts have the ability to renew themselves and to differentiate into cell types of all lineage. The present study was carried out to investigate whether the Wnt signaling pathway is related to maintaining self-renewal of hESCs. Glycogen Synthase Kinase 3 (GSK-3) inhibitor, BIO ((2'Z,3'E)-6-Bromoindirubin-3'-oxime) was treated to Miz-hES1 line for activation of Wnt signaling pathway. BIO-nontreated hESCs (control) and BID-treated hESCs were cultured for 5 days in the modified feeder-free system. During the culture of hESCs, differences were observed in the colony morphology between 2 groups. Controls were spread outwards whereas BIO-nontreated hESCs were clumped in the center and the differentiated cells were spreading outwards in the edges. The results of stem cell specific marker staining indicated that control were differentiated in large part whereas BIO-treated hESCs maintain self-renewal in the center of the colony. The results of lineage marker staining suggested that outer cells of the hESC colony were differentiated to the neuronal progenitor cells in both control and BIO-treated hESC. These results indicate that Wnt signaling is related to self-renewal in hESCs. In addition, control group showed higher composition of apoptotic cells $(23.76\%)$ than the BID-treated group $(5.59\%)$. These results indicate that BIO is effective on antapoptosis of hESCs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.2
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• pp.416-425
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• 2009

Angiogenesis is important for promoting cardiovascular disease, wound healing, and tissue regeneration. We here investigated the pharmacological effects of Korea red ginseng water extract (KRGE) on angiogenesis and its underlying signal mechanism. This study showed that KRGE increased in vitro proliferation, migration, and tube formation of human umbilical endothelial cells, as well as stimulated in vivo angiogenesis. KRGE-induced angiogenesis was accompanied by phosphorylation of ERK1/2, Akt, and endothelial nitric oxide synthase (eNOS) as well as an increase in NO production. Inhibition of PI3K activity by wortmannin completely inhibited KRGE-induced angiogenesis and phosphorylation of Akt, ERK1/2, and eNOS, indicating that PI3K/Akt activation is an upstream event of KRGE-mediated angiogenic pathway. The MEK inhibitor PD98059 completely blocked KRGE-induced angiogenesis and ERK phosphorylation without affecting Akt and eNOS activation. However, the eNOS inhibitor NMA effectively inhibited tube formation, but partially blocked proliferation and migration as well as ERK phosphorylation without altering Akt and eNOS activation, revealing that eNOS/NO pathway is in part involved in ERK1/2 activation. This study first demonstrated the critical involvement of both ERK1/2 and eNOS activation in KRGE-induced angiogenesis, which lie on downstream of PI3K/Akt. Thus, these results indicate that KRGE requires activation of both the PI3K/Akt-dependent ERK1/2 and eNOS signal pathways and their cross-talk for its full angiogenic activity.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.143-147
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• 2011

Defensins, cysteine-rich cationic polypeptides released from neutrophils, are known to have powerful antimicrobial properties. In this study, we sacrificed 30 rats to investigate the effects of ${\alpha}$-defensin 1 on detrusor muscle contractions in isolated rat bladder. From the experiments we found relaxing effects of ${\alpha}$-defensin 1 on the contractions induced by phenylephrine (PE) but not by bethanechol (BCh) in the detrusor smooth muscles. To determine the mechanisms of the effects of ${\alpha}$-defensin 1, the changes of effects on PE-induced contraction by ${\alpha}$-defensin 1 pretreatment were observed after pretreatment of Rho kinase inhibitor (Y-27632), protein kinase C (PKC) inhibitor (Calphostin C), potent activator of PKC (PDBu; phorbol 12,13-dibutyrate), and NF-${\kappa}B$ inhibitors (PDTC; pyrrolidinedithiocarbamate and sulfasalazine). The contractile responses of PE ($10^{-9}{\sim}10^{-4}$ M) were significantly decreased in some concentrations of ${\alpha}$-defensin 1 ($5{\times}10^{-9}$ and $5{\times}10^{-8}$ M). When strips were pretreated with NF-kB inhibitors (PDTC and sulfasalazine; $10^{-7}{\sim}10^{-6}$ M), the relaxing responses by ${\alpha}$-defensin 1 pretreatment were disappeared. The present study demonstrated that ${\alpha}$-defensin 1 has relaxing effects on the contractions of rat detrusor muscles, through NF-${\kappa}B$ pathway. Further studies in vivo are required to clarify whether ${\alpha}$-defensin 1 might be clinically related with bladder dysfunction by inflammation process.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.687-694
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• 2017

Plumbagin, a hydroxy 1,4-naphthoquinone compound from plant metabolites, exhibits anticancer, antibacterial, and antifungal activities via modulating various signaling molecules. However, its effects on vascular functions are rarely studied except in pulmonary and coronary arteries where NADPH oxidase (NOX) inhibition was suggested as a mechanism. Here we investigate the effects of plumbagin on the contractility of skeletal artery (deep femoral artery, DFA), mesenteric artery (MA) and renal artery (RA) in rats. Although plumbagin alone had no effect on the isometric tone of DFA, $1{\mu}M$ phenylephrine (PhE)-induced partial contraction was largely augmented by plumbagin (${\Delta}T_{Plum}$, 125% of 80 mM KCl-induced contraction at $1{\mu}M$). With relatively higher concentrations (>$5{\mu}M$), plumbagin induced a transient contraction followed by tonic relaxation of DFA. Similar biphasic augmentation of the PhE-induced contraction was observed in MA and RA. VAS2870 and GKT137831, specific NOX4 inhibitors, neither mimicked nor inhibited ${\Delta}T_{Plum}$ in DFA. Also, pretreatment with tiron or catalase did not affect ${\Delta}T_{Plum}$ of DFA. Under the inhibition of PhE-contraction with L-type $Ca^{2+}$ channel blocker (nifedipine, $1{\mu}M$), plumbagin still induced tonic contraction, suggesting $Ca^{2+}$-sensitization mechanism of smooth muscle. Although ${\Delta}T_{Plum}$ was consistently observed under pretreatment with Rho A-kinase inhibitor (Y27632, $1{\mu}M$), a PKC inhibitor (GF 109203X, $10{\mu}M$) largely suppressed ${\Delta}T_{Plum}$. Taken together, it is suggested that plumbagin facilitates the PKC activation in the presence of vasoactive agonists in skeletal arteries. The biphasic contractile effects on the systemic arteries should be considered in the pharmacological studies of plumbagin and 1,4-naphthoquinones.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.445-454
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• 2007

Background: Phosphatidic acid(PA), an important second messenger, is involved in inflammation. Notably, cell-cell interactions via adhesion molecules playa central role in inflammation. This thesis show that PA induces expression of intercellular adhesion molecule-1(ICAM-1) on macrophages and describe the signaling pathways. Materials and methods: Macrophages were cultured in the presence of 10% FBS and assayed cell to cell adhesion using HUVEC. For the gene and protein analysis, RT-PCR, Western blot and flow cytometry were performed. In addition, overexpressed cell lines for dominant negative PKC-${\delta}$ mutant established and tested their effect on the promoter activity and expression of ICAM-1 protein by PA. Results: PA-activated macrophages significantly increased adhering to human umbilical vein endothelial cell and this adhesion was mediated by ICAM-1. Pretreatment with rottlerin(PKC-${\delta}$ inhibitor) or expression of a dominant negative PKC-${\delta}$ mutant, but not Go6976(classical PKC-${\alpha}$ inhibitor) and myristoylated PKC-${\xi}$ inhibitor, attenuated PA-induced ICAM-1 expression. The p38 mitogen-activated protein kinase(MAPK) inhibitor blocked PA-induced ICAM-1 expression in contrast, ERK upstream inhibitor didn't block ICAM-1. Conclusion: These data suggest that PA-induced ICAM-1 expression and cell-cell adhesion in macrophages requires PKC-${\delta}$ activation and that PKC-${\delta}$ activation is triggers to sequential activation of p38 MAPK.

• Journal of Ginseng Research
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• v.35 no.2
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• pp.200-208
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• 2011

Ginsenoside (G) $Rp_1$ is a ginseng saponin derivative with anti-cancer and anti-inflammatory activities. In this study, we examined the mechanism by which G-$Rp_1$ inhibits inflammatory responses of cells. We did this using a strategy in which DNA constructs containing cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) promoters were transfected into HEK293 cells. G-$Rp_1$ strongly inhibited the promoter activities of COX-2 and iNOS; it also inhibited lipopolysaccharide induced upregulation of COX-2 and iNOS mRNA levels in RAW264.7 cells. In HEK293 cells G-$Rp_1$ did not suppress TANK binding kinase 1-, Toll-interleukin-1 receptor-domain-containing adapter-inducing interferon-${\beta}$ (TRIF)-, TRIF-related adaptor molecule (TRAM)-, or activation of interferon regulatory factor (IRF)-3 and nuclear factor (NF)-${\kappa}$B by the myeloid differentiation primary response gene (MyD88)-induced. However, G-$Rp_1$ strongly suppressed NF-${\kappa}$B activation induced by I${\kappa}$B kinase (IKK)${\beta}$ in HEK293 cells. Consistent with these results, G-$Rp_1$ substantially inhibited IKK${\beta}$-induced phosphorylation of $I{\kappa}B{\alpha}$ and p65. These results suggest that G-$Rp_1$ is a novel anti-inflammatory ginsenoside analog that can be used to treat IKK${\beta}$/NF-${\kappa}$B-mediated inflammatory diseases.

• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.650-657
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• 2021

Metformin is an anti-diabetic drug and has anticancer effects on various cancers. Several studies have suggested that metformin reduces cell proliferation and stimulates cell-cycle arrest and apoptosis. However, the definitive molecular mechanism of metformin in the pathophysiological signaling in endometrial tumorigenesis and metastasis is not clearly understood. In this study, we examined the effects of metformin on the cell viability and apoptosis of human cervical HeLa and endometrial HEC-1-A and KLE cancer cells. Metformin suppressed cell growth in a dose-dependent manner and dramatically evoked apoptosis in HeLa cervical cancer cells, while apoptotic cell death and growth inhibition were not observed in endometrial (HEC-1-A, KLE) cell lines. Accordingly, the p27 and p21 promoter activities were enhanced while Bcl-2 and IL-6 activities were significantly reduced by metformin treatment. Metformin diminished the phosphorylation of mTOR, p70S6K and 4E-BP1 by accelerating adenosine monophosphate-activated kinase (AMPK) in HeLa cancer cells, but it did not affect other cell lines. To determine why the anti-proliferative effects are observed only in HeLa cells, we examined the expression level of liver kinase B1 (LKB1) since metformin and LKB1 share the same signalling system, and we found that the LKB1 gene is not expressed only in HeLa cancer cells. Consistently, the overexpression of LKB1 in HeLa cancer cells prevented metformin-triggered apoptosis while LKB1 knockdown significantly increased apoptosis in HEC-1-A and KLE cancer cells. Taken together, these findings indicate an underlying biological/physiological molecular function specifically for metformin-triggered apoptosis dependent on the presence of the LKB1 gene in tumorigenesis.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.212-218
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• 2010

Korean red ginseng (KRG) has been shown to enhance endothelium-dependent vasorelaxation in experimental animals; however, little is known about its pharmacological effects on vascular stiffness in patients with coronary artery disease (CAD). This randomized, double-blind, placebo-controlled crossover trial was carried out to determine whether KRG has beneficial effects on arterial stiffness, cardiovascular risk factors such as plasma lipid profiles and blood pressure (BP), and Rho-associated kinase (ROCK) activity. Twenty patients (mean age, 62.5 years) with stable angina pectoris were given KRG (2.7 g/day) and a placebo alternatively for 10 weeks. Blood biochemical analysis and pulse wave velocity (PWV) recording were performed on day 0 and after the completion of each treatment. ROCK activity was assessed based on the level of phospho-$Thr^{853}$ in the myosin-binding subunit of myosin light chain phosphatase, determined by Western blot analysis of peripheral blood mononuclear cells. KRG significantly decreased the systolic BP, brachial ankle PWV, and heart femoral PWV in the patients (all p<0.05), but did not significantly alter the serum lipid profiles, including triglycerides and total, high-density lipoprotein, and low-density lipoprotein cholesterol levels. The ROCK activity tended to decrease (p=0.068) following KRG treatment. The placebo did not significantly alter any of the variables. In conclusion, KRG decreased systolic BP and arterial stiffness, probably via the inhibition of ROCK activity, in patients with CAD, but had a neutral effect on serum lipid profiles. Our data suggest that KRG has a therapeutic effect on CAD.