• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1045-1050
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• 2002

The aims of this study were to detect spontaneously occurring apoptosis in cultured porcine ovarian cells, to examine the role of growth hormone (GH), tyrosine kinase (TK), protein kinase G (PKG) and cyclin-dependent kinase (CDK) in the control of this process, and to determine whether the effect of GH on apoptosis is mediated by TK-, PKG- and cdc2-dependent intracellular mechanisms. We studied the action of pGH (10 ng/ml), blockers of TK (genistein, lavendustin, both 100 ng/ml), PKG (Rp-Br-PET-cGMPS, 50 nM; KT5823, 100 ng/ml) and CDK (olomoucine, $1{\mu}g/ml$), as well as combinations of GH with these blockers, on the onset of apoptosis in cultured granulosa cells isolated from antral (3-6 mm) porcine follicles. The functional characteristics of an early apoptotic event, DNA fragmentation, were determined using terminal deoxynucleotidyltransferase (TdT)-mediated dUTP nick end labelling (TUNEL), whilst morphological signs of advanced apoptosis such as pyknosis, chromatin marginalization, shrinkage and fragmentation of nucleus, were detected using routine light microscopy. After culture, some ovarian granulosa cells exhibited DNA fragmentation, which in some cases was associated with morphological apoptosis-related changes (pyknosis, shrinkage and fragmentation of the nucleus). GH significantly reduced the proportion of TUNEL-positive cells. Neither TK nor CDK blockers when given alone, significantly affected the percentage of TUNEL-positive cells although both PKG blockers significantly increased this index. Furthermore, TK and PKG blockers given together with GH, prevented or reversed the inhibitory effect of GH on apoptosis, whilst the CDK blocker olomoucine promoted it. These observations demonstrate apoptosis in porcine ovaries and suggest the involvement of GH, TK, PKG and CDK in the control of this process. They also suggest that the effect of GH on ovarian apoptosis is mediated or regulated by multiple signalling pathways including TK-, PKG- and CDK-dependent intracellular mechanisms.

• Development and Reproduction
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• v.4 no.2
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• pp.243-250
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• 2000

To find the mechanism underlying the ADP-induced increase in the outward current in ovulated mouse oocytes, we examined changes in voltage-dependent currents using the whole cell voltage clamp technique and the internal perfusion technique. Eggs were collected from the oviduct of superovulated mice with PMSG and hCG. Membrane potential was held at -60 mV (or -80 mV in the case of recording $Ca^{2＋}$ currents) and step depolarizations or hyperpolarizations were applied for 300 ms. By step depolarizations, outward currents comprising steady-state and time-dependent components were elicited. They were generated in response to the positive potential more than 20 mV with severe outward rectification and were blocked by external TEA, a specific $K^{＋}$ channel blocker, suggesting that they be carried via $K^{＋}$ channels. Internally-perused 5 mM ADP gradually increased outward $K^{＋}$ currents (IK) 1 min after perfusion of ADP and reached slowly to maximum (150~170％) 5 min later over the positive potential range, implying that ADP might not be acted directly to the $K^{＋}$ channels. IK were decreased by 5 mM ATP without affecting the steady-state component of outward current. In contrast to the effect of ADP and ATP on IK, both effect of ATP and ADP on inward $Ca^{2＋}$ currents (ICa) could not be detected due to the continuous decrease in current amplitudes with time-lapse ("run-down" phenomena). To check if there is a G protein-involved regulation in the ionic current of mouse oocytes, 1 mM GTP was applied to the cytoplasmic side, and the outward current and inward currents were recorded. ICa was promptly increased in the presence of GTP whereas IK was not changed. from these results, it is concluded that the ATP-dependent regulation is likely linked in the ADP-induced increase in the outward $K^{＋}$ current, and G protein-involved cellular signalling might affect ion channels carrying $Ca^{2＋}$ and $K^{＋}$ in mouse oocytes.

• The Journal of Internal Korean Medicine
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• v.26 no.3
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• pp.575-586
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• 2005

FC(free choresterol) plays an important role in normal and pathophysiological cells including that of messenger molecule or dilator of blood vessels in such illnesses as artheriosclerosis, hypertension and myocardial infarction. Smooth muscle and endothelial cell functions in the arteria wall are unified by complex intercellular signalling processes. In arteria comprised of one layer of smooth muscle cells surrounding the endothelium, the close apposition of the two cell types enables a signal derived from one cell to rapidly diffuse to neighboring cells. Experimentation was conducted to investigate the potential contribution of Sohaphyangwon(SHHW) on levels of FC generated by goaded microphages, and mechanisms of protection against ACAT inhibitor. It was found that J774 macrophages, which normally do not express FC were expressed by oxLDL and ACAT inhibitor. SHHW protected cells were found to be resistant to oxLDL and delayed death following the FC. Inhibition of FC formation abolished the protective effect against ACAT inhibitor exposure. Cadiovascular diseases include abnormalities of blood vessels dysfunction of the renin-angiotension system. What relation herbal medicine may have with vessel endothelium necrosis was here studied. In Oriental Medicine, SHHW water extract used for diseases in relation to cardiovascular systems. The resistence to cardiovascular disease of ACAT inhibitor induced J774 macrophage cells were studied through analysis of cell morphological patterns and immunochemistry of SHHW. The results of this study suggest that SHHW has protective effects on the cardiovascular system, and that it is effective in both prevention and treatment of diseases of the cardiovascular system, particularity against necrosis of blood.

• The Journal of the Korea Contents Association
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• v.18 no.3
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• pp.557-567
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• 2018

This paper studies the relationship between general investors' allotment ratio and underpricing for the companies that were newly listed in KOSDAQ market after the 20% rule, from March 2004 to December 2013, by empirical analysis. It is shown that the excess allotment ratio over 20% has a strong explanatory power for underpricing ratio under the 1% significance level. Furthermore, the general investors' allotment ratio is a significant explanatory variable of underpricing ratio under the 5% significance level. There are many hypotheses about underpricing, however, if underpricing is evident with high allocation ratio for general investors, it can be regarded as a signal of company's confidence in earnings after listing. In conclusion, this study reveals that general investors' allotment ratio can be used as a major explanatory variable that has a significant effect on the degree of undervaluation in the IPO market.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6247-6251
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• 2014

Background: The aim of the present study was to investigate the involvement of emodin on the growth of human breast cancer MCF-7 and MDA-MB-231 cells and the estrogen (E2) signal pathway in vitro. Materials and Methods: MTT assays were used to detect the effects of emodin on E2 induced proliferation of MCF-7 and MDA-MB-231 cells. Flow cytometry (FCM) was applied to determine the effect of emodin on E2-induced apoptosis of MCF-7 cells. Western blotting allowed detection of the effects of emodin on the expression of estrogen receptor ${\alpha}$, cyclin D1 and B-cell lymphoma-2 (Bcl-2), mitogen-activated protein kinases (MAPK) and phosphatidylinostiol 3-kinases (PI3K). Luciferase assays were emplyed to assess transcriptional activity of $ER{\alpha}$. Results: Emodin could inhibit E2-induced MCF-7 cell proliferation and anti-apoptosis effects, and arrest the cell cycle in G0/G1 phase, further blocking the effect of E2 on expression and transcriptional activity of $ER{\alpha}$. Moreover, Emodin influenced the ER ${\alpha}$ genomic pathway via downregulation of cyclin D1 and Bcl-2 protein expression, and influenced the non-genomic pathway via decreased PI3K/Akt protein expression. Conclusions: These findings indicate that emodin exerts inhibitory effects on MCF-7 cell proliferation via inhibiting both non-genomic and genomic pathways.

• Molecules and Cells
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• v.39 no.10
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• pp.742-749
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• 2016

The cancer chemo-preventive effects of equol have been demonstrated for a wide variety of experimental tumours. In a previous study, we found that equol inhibited proliferation and induced apoptotic death of human gastric cancer MGC-803 cells. However, the mechanisms underlying equol-mediated apoptosis have not been well understood. In the present study, the dual AO (acridine orange)/EB (ethidium bromide) fluorescent assay, the comet assay, MTS, western blotting and flow cytometric assays were performed to further investigate the pro-apoptotic effect of equol and its associated mechanisms in MGC-803 cells. The results demonstrated that equol induced an apoptotic nuclear morphology revealed by AO/EB staining, the presence of a comet tail, the cleavage of caspase-3 and PARP and the depletion of cIAP1, indicating its pro-apoptotic effect. In addition, equol-induced apoptosis involves the mitochondria-dependent cell-death pathway, evidenced by the depolarization of the mitochondrial membrane potential, the cleavage of caspase-9 and the depletion of Bcl-xL and full-length Bid. Moreover, treating MGC-803 cells with equol induced the sustained activation of extracellular signal-regulated kinase (ERK), and inhibiting ERK by U0126, a MEK/ERK pathway inhibitor, significantly attenuated the equol-induced cell apoptosis. These results suggest that equol induces mitochondria-dependent apoptosis in human gastric cancer MGC-803 cells via the sustained activation of the ERK1/2 pathway. Therefore, equol may be a novel candidate for the chemoprevention and therapy of gastric cancer.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.241-247
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• 2016

Natamycin is a widely used antifungal antibiotic. For natamycin biosynthesis, the gene pimE encodes cholesterol oxidase, which acts as a signalling protein. To confirm the positive effect of the gene pimE on natamycin biosynthesis, an additional copy of the gene pimE was inserted into the genome of Streptomyces gilvosporeus 712 under the control of the ermE* promoter (p_ermE*) using intergeneric conjugation. Overexpression of the target protein engendered 72% and 81% increases in the natamycin production and cell productivity, respectively, compared with the control strain. Further improvement in the antibiotic production was achieved in a 1 L fermenter to 7.0 g/l, which was a 153% improvement after 120 h cultivation. Exconjugants highly expressing pimE and pimM were constructed to investigate the effects of both genes on the increase of natamycin production. However, the co-effect of pimE and pimM did not enhance the antibiotic production obviously, compared with the exconjugants highly expressing pimE only. These results suggest not only a new application of cholesterol oxidase but also a useful strategy to genetically engineer natamycin production.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.3
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• pp.117-134
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• 2009

Purpose: In the theory of traditional medicine, Scutellariae Radix (SR) can clear away heat and remove dampness, purge the sthenic fire and remove toxic materials, cool blood and stop bleeding to prevent miscarriage. Recently, SR is known to have anti-cancer activity. For this reason, the present author designed to investigate the effect of SR on proliferation rates of cervical cancer cell line, then effects on genetic profile by SR. Methods: The genetic profile for the effect of SR on human derived cervical cancer cell line, SNU-703, was measured using microarray technique, and the functional analysis on these genes was conducted. Results: Total 519 genes were up-regulated and 606 genes down-regulated in cells treated with SR. Genes induced or suppressed by SR were all mainly concerned with metabolic process, regulation of biological process and protein binding. The network of total protein interactions was measured using cytoscape program, and some key molecules, such as TNFRSF1A, AKT1, MAPK3, and STAT3 that can be used for elucidation of therapeutical mechanism of medicine in future were identified. Conclusion: These results suggest possibility of SR as anti-cancer drug and also suggest that related mechanisms are involved in TNFRSF1A, AKT1, MAPK3, and STAT3 related signalling pathways.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.66-83
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• 2002

Recently, we have provided evidence that ginsenosides, the active components of Panax ginseng, utilize pertussis toxin (PTX)-insensitive $G{\alpha}_{q/11}-phospholipase\;C-{\beta}3(PLC-{\beta}3)$ signal transduction pathway for the enhancement of $Ca^{2+}-activated\;Cl^{-}$ current in the Xenopus oocyte (British J. Pharmacol. 132, 641-647, 2001; JBC 276, 48797-48802, 2001). Other investigators have shown that stimulation of receptors linked to $G{\alpha}-PLC$ pathway inhibits the activity of G proteincoupled inwardly rectifying $K^+$ (GIRK) channel. In the present study, we sought to determine whether ginsenosides influenced the activity of GIRK 1 and GIRK 4 (GIRK 1/4) channels expressed in the Xenopus oocyte, and if so, the underlying signal transduction mechanism. In oocyte injected with GIRK 1/4 channel cRNAs, bath-applied ginsenosides inhibited high potassium (HK) solution-elicited GIRK current $(EC_{50}:4.9{\pm}4.3\;{\mu}g/ml).$ Pretreatment of the oocyte with PTX reduced the HK solution-elicited GIRK current by $49\%,$ but it did not alter the inhibitory ginsenoside effect on GIRK current. Prior intraoocyte injection of cRNA(s) coding $G{\alpha}_q,\;G{\alpha}_{11}\;or\;G{\alpha}_q/G{\alpha}_{11},\;but\;not\;G{\alpha}_{i2}\;or\;G{\alpha}_{oA}$ attenuated the inhibitory ginsenoside effect. Injection of cRNAs coding $G{\beta}_{1{\gamma}2}$ also attenuated the ginsenoside effect. Similarly, injection of the cRNAs coding regulators of G protein signaling 1, 2 and 4 (RGS1, RGS2 and RGS4), which interact with $G{\alpha}_i\;and/or\;G{\alpha}_{q/11}$ and stimulates the hydrolysis of GTP to GDP in active GTP-bound $G{\alpha}$ subunit, resulted in a significant reduction of ginsenoside effect on GIRK current. Preincubation of GIRK channel-expressing oocyte in PLC inhibitor (U73122) or protein kinase C (PKC) inhibitor (staurosporine or chelerythrine) blocked the inhibitory ginsenoside effect on GIRK current. On the other hand, intraoocyte injection of BAPTA, a free $Ca^{2+}$ chelator, had no significant effect on the ginsenoside action. Taken together, these results suggest that ginsenosides inhibit the activity of GIRK 1/4 channel expressed in the Xenopus oocyte through a PTX-insensitive and $G{\alpha}_{q/11}$-,PLC-and PKC-mediated signal transduction pathway.

• Journal of Oral Medicine and Pain
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• v.26 no.1
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• pp.39-50
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• 2001

In order to investigate the effect of Transforming growth factor ${\beta}1$(below TGF-${\beta}1$) and osteogenic protein-1(below Op-1) onto the myogenic differentiation, C2C12 satellite myoblastic cell line was cultured and treated with both growth factors. At first morphological changes with microscopical examination were examined, and isolated total RNA to analyse mRNA expression of bone marker proteins, muscle regulatory proteins, TGF-${\beta}$ receptor and their ligands by Northern blot analysis. And cellular proliferative inducibility of both growth factors was also tested to C2C12 cells. Incubating the cell with $5ng/m{\ell}$ of TGF-${\beta}1$ until 4 days almost inhibited multinucleated myotube formation expressing muscular regulatory proteins, and induced decreasing Id proteins. However, no osteoblastic phenotypes was induced by TGF-${\beta}1$ in C2C12 cells. The mRNA expression of TGF-${\beta}$ receptors with TGF-${\beta}1$ was conversed after 48 hours cultured. Type I TGF-${\beta}$ receptor was seemed to play a role in negative signalling for inhibition of myogenic differentiation. OP-1 dose dependently induced ALP activity, osteopontine production and bone sialoprotein production at concentrations above $100ng/m{\ell}$ and osteocalcin production at concentrations above $300ng/m{\ell}$. The concentration of OP-1 required to induce these osteoblastic phenotypes was the same as that required to almost completely inhibit myotube formation. Incubation with above $100ng/m{\ell}$ OP-1 suppressed the expression of mRNA for muscular egulatory proteins from 2 days after incubation. Expression of Id-1, 2, 3 mRNA were stimulated by OP-1 at concentration above $300ng/m{\ell}$. When C2C12 cells were treated with both growth factors, TGF-${\beta}1$ potentiated the inhibitory effect of OP-1 on myotube formation and expression of mRNA for myogenin at 12 days. And TGF-${\beta}1$ reduced osteocalcin and bone sialoprotein production induced by OP-1 at 12 days in C2C12 cells. Both growth factor had no mitogenic effect. These results indicate that OP-1 converts the differentiation pathway of C2C12 myoblasts into that of osteoblastic lineage cells and it's not heritable, but TGF-${\beta}1$ does not and has reversible inhibitory activity on the myogenic differentiation. TGF-${\beta}1$ and OP-1 play a role in myogenic differentiation via different mechanism between them.