• The Korean Journal of Physiology and Pharmacology
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• v.26 no.4
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• pp.255-262
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• 2022

Oxytocin is a neuropeptide produced primarily in the hypothalamus and plays an important role in the regulation of mammalian birth and lactation. It has been shown that oxytocin has important cardiovascular protective effects. Here we investigated the effects of oxytocin on vascular reactivity and underlying the mechanisms in human umbilical vein endothelial cells (HUVECs) in vitro and in rat aorta ex vivo. Oxytocin increased phospho-eNOS (Ser 1177) and phospho-Akt (Ser 473) expression in HUVECs in vitro and the aorta of rat ex vivo. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), inhibited oxytocin-induced Akt and eNOS phosphorylation. In the rat aortic rings, oxytocin induced a biphasic vascular reactivity: oxytocin at low dose (10^-9-10^-8 M) initiated a vasorelaxation followed by a vasoconstriction at high dose (10^-7 M). L-NAME (a nitric oxide synthase inhibitor), endothelium removal or wortmannin abolished oxytocin-induced vasorelaxation, and slightly enhanced oxytocin-induced vasoconstriction. Atosiban, an oxytocin/vasopressin 1a receptor inhibitor, totally blocked oxytocin-induced relaxation and vasoconstriction. PD98059 (ERK1/2 inhibitor) partially inhibited oxytocin-induced vasoconstriction. Oxytocin also increased aortic phospho-ERK1/2 expression, which was reduced by either atosiban or PD98059, suggesting that oxytocin-induced vasoconstriction was partially mediated by oxytocin/V1aR activation of ERK1/2. The present study demonstrates that oxytocin can activate different signaling pathways to cause vasorelaxation or vasoconstriction. Oxytocin stimulation of PI3K/eNOS-derived nitric oxide may participate in maintenance of cardiovascular homeostasis, and different vascular reactivities to low or high dose of oxytocin suggest that oxytocin may have different regulatory effects on vascular tone under physiological or pathophysiological conditions.

• Reproductive and Developmental Biology
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• v.33 no.4
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• pp.203-209
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• 2009

The present study was performed to identify changes of plasminogen activator (PA) and plasminogen activator inhibitor (PAI) in porcine oviduct epithelial cells (POECs) during the estrous cycle. POECs obtained from ovary in pre-ovulatory (Pre-Ov), early to mid-luteal stage (Early-mid L) and post-ovulatory stage (Post-Ov). For the examine of PA activity, $1{\times}10^5$ fresh cells of POECs were cultured in DMEM/Ham F-12 containing 10% FBS and 0.2% amphotericin under humidified atmosphere of 5% $CO_2$ in air and $38^{\circ}C$. The urokinase-type PA (uPA) was observed at 7 days of POECs culture. PA activity was measured with culture prolonged of 0, 3, 6, 12 and 24 h after culture of 7 days. The PA activity were high significantly (p<0.05) at 12 h of culture, but PA activity were decreased with culture periods increased. The PA activity in POECs of Post-Ov stage were higher significantly (p<0.05) than that of Early-mid L and Pre-Ov stage. When PAI-1 and PAI-2 were added during the POECs culture, the PA were observed significant low activity (p<0.05). The PA activity and protein expression were decreased by PA inhibitor. This results suggest that PAI-1 and PAI-2 have a suppressive action on change of PA activity during the estrous cycle of pigs. Specifically, this study using PA inhibitor was effect the PA activity and PAI expression in oviduct epithelial cells in pigs.

• The Journal of Natural Sciences
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• v.14 no.2
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• pp.93-102
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• 2004

A yeast strain SL-27 found to produce active intracellular tyrosinase inhibitor was screened from 972 kinds of yeasts. It was identified as Malassezia pachydermatis based on microbiological characteristics. The optimum pH and temperature for the growth of Malassezia pachydermatis SL-27 were pH 7.0 and $37^{\circ}C$, respectively. The optimal culture conditions for the production of tyrosinase inhibitor by Malassezia pachydermatis SL-27 were investigated. The optimal medium cimposition for tyrosinase inhibitor production was determined to be 1.0% casamino acid, 2.0% glucose, 0.1% $KH_2PO_4$, 0.05% $MgSo_{4-}7H20$ and each 0.01 of $CaCl_2$ and NaCl. Optimal initial pH and temperature for the production of tyrosinase inhibitor were pH 5.0 and $30^{\circ}C$, respectively. The maximum tyrosinase inhibitory activity of 84%/mL of cell-free extract was showed after 12 h of cultivation under the optimal culturing conditions.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.470-475
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• 2002

In the course of screening for a novel cell cycle inhibitor, a potent Cdk 1 inhibitor, HY558, was found from the culture broth of Penicillium minioluteum F558 isolated from a soil sample. The molecular ion of HY558 was identified at m/z 329 (MH+) with a molecular formula of $C_20H_44ON_2$. HY558 exhibited selective antiproliferative effects on various human cancer cell lines. Its $IC_50$ values were estimated to be 0.29 mM on HepG2, 0.30 mM on HeLa, 0.30 mM on HL6O, 0.33 mM on HT-29, and 0.25 mM on AGS cells. Interestingly, Hy558 demonstrated no antiproliferative effect with normal lymphocytes used as the control, and a low level of inhibition on the proliferation of A549 cancer cells. A flow cytometric analysis of HepG2 cells revealed an appreciable arrest of cells at the G1 and G2/M phases of the cell cycle following treatment with Hy558. furthermore, DNA fragmentation due to apoptosis was observed in HeLa cells treated with 0.46 mM of HY558.

• Biomolecules & Therapeutics
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• v.20 no.2
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• pp.214-219
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• 2012

This research was designed to determine what components of Gardenia jasminoides play a major role in inhibiting the enzymes related antidepressant activity of this plant. In our previous research, the ethyl acetate fraction of G. jasminosides fruits inhibited the activities of both monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B), and oral administration of the ethanolic extract slightly increased serotonin concentrations in the brain tissues of rats and decreased MAO-B activity. In addition, we found through in vitro screening test that the ethyl acetate fraction showed modest inhibitory activity on dopamine-${\beta}$ hydroxylase (DBH). The bioassay-guided fractionation led to the isolation of five bio-active compounds, protocatechuic acid (1), geniposide (2), 6'-O-trans-p-coumaroylgeniposide (3), 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl) heptanes (4), and ursolic acid (5), from the ethyl acetate fraction of G. jasminoides fruits. The isolated compounds showed different inhibitory potentials against MAO-A, -B, and DBH. Protocatechuic acid showed potent inhibition against MAO-B ($IC_{50}$ $300{\mu}mol/L$) and DBH ($334{\mu}mol/L$), exhibiting weak MAO-A inhibition (2.41 mmol/L). Two iridoid glycosides, geniposide ($223{\mu}mol/L$) and 6'-O-trans-p-coumaroylgeniposide ($127{\mu}mol/L$), were selective MAO-B inhibitor. Especially, 6'-O-trans-p-coumaroylgeniposide exhibited more selective MAO-B inhibition than deprenyl, well-known MAO-B inhibitor for the treatment of early-stage Parkinson's disease. The inhibitory activity of 3,5-dihydroxy-1,7-bis (4-hydroxyphenyl) heptane was strong for MAO-B ($196{\mu}mol/L$), modest for MAO-A ($400{\mu}mol/L$), and weak for DBH ($941{\mu}mol/L$). Ursolic acid exhibited significant inhibition of DBH ($214{\mu}mol/L$), weak inhibition of MAO-B ($780{\mu}mol/L$), and no inhibition against MAO-A. Consequently, G. jasminoides fruits are considerable for development of biofunctional food materials for the combination treatment of depression and neurodegenerative disorders.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.382-386
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• 1995

The potato proteinase inhibitor II (PI-II) protein contains chymotrypsin and trypsin inhibitory site. Among several PI-II genes isolated from genomic library, amino acid sequence deduced from PI-IIT gene has 84% identity with that of the polypeptide chymotrypsin inhibitor (PCI). Therefore a gene fragment having homology with the PCI was cloned into a vector using polymerase chain reaction(PCR) from the potato proteinase inhibitor IIT gene. Two different primers were utilized for cloning; primer A contains NdeI restriction site and 30 nucleotides, which has AUG N-terminal methionine codon, primer B contains BclI restriction site and 28 nucleotides, which has TAG translation stop codon. After PCR, about 160 bp-long DNA fragment was cloned into pRT146, derivative of pUC118, and sequenced. The sequenced NdeI/BclI fragment was moved to pET3a, containing bacteriophage T7 promoter and terminator. The expressed proteins in E. coli BL2l(DE3) were determined on a polyacrylamide gel containing sodium dodecyl sulfate. The expected size of protein deduced from the sequenced gene fragment is about 6,500 dalton whose size was similar to the IPTG-induced protein (6,000 dalton) on a gel. However the expression level was much lower than expected.

• Molecules and Cells
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• v.21 no.2
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• pp.237-243
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• 2006

Brain-derived neurotrophic factor (BDNF) is a neuromodulator of nociceptive responses in the dorsal root ganglia (DRG) and spinal cord. BDNF synthesis increases in response to nerve growth factor (NGF) in trkA-expressing small and medium-sized DRG neurons after inflammation. Previously we demonstrated differential activation of multiple BDNF promoters in the DRG following peripheral nerve injury and inflammation. Using reporter constructs containing individual promoter regions, we investigated the effect of NGF on the multiple BDNF promoters, and the signaling pathway by which NGF activates these promoters in PC12 cells. Although all the promoters were activated 2.4-7.1-fold by NGF treatment, promoter IV gave the greatest induction. The p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580, phosphatidylinositol 3-kinase (PI-3K) inhibitor, LY294003, protein kinase A (PKA) inhibitor, H89, and protein kinase C (PKC) inhibitor, chelerythrine, had no effect on activation of promoter IV by NGF. However, activation was completely abolished by the MAPK kinase (MEK) inhibitors, U0126 and PD98059. In addition, these inhibitors blocked NGF-induced phosphorylation of extracellular signal-regulated protein kinase (ERK) 1/2. Taken together, these results suggest that the ERK1/2 pathway activates BDNF promoter IV in response to NGF independently of NGF-activated signaling pathways involving PKA and PKC.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.2
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• pp.135-139
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• 2003

Objective: We investigated whether serum testosterone to estradiol ratio was decreased in infertile men and whether this condition can be corrected with oral aromatase inhibitor. Method: The serum testosterone to estradiol ratio of 26 men with testicular failure were compared with those of normal semen analysis parameter, 89 control reference group. All of 26 testicular failure group were diagnosed with the previous testicular biopsy. Then 46 men with oligospermia and/or asthenospermia were selected and treated with 1 mg of the aromatase inhibitor anastrozole ($Arimidex^{(R)}$) orally once daily for 3 months. Testosterone to estradiol ratio and semen analyses were evaluated during anastrozole therapy. Results: The testosterone level of testicular failure group was significantly lower and the testosterone to estradiol ratio was more decreased than normal semen parameter group. Forty six on-anastrozole group had significantly lower testosterone (4.6 versus 5.7 ng/ml, p<0.01) and higher estradiol (15.9 versus 23.4 pg/ml, p<0.01) than pre-anastrozole group, resulting in a decreased testosterone to estradiol ratio ($0.21{\pm}0.07$ versus $0.39{\pm}0.15$, p<0.01). Semen analyses before and during anastrozole treatment revealed significant increases in sperm count (35.5 versus 52.2 million sperm per ml, p<0.01) and motility (22.9% versus 29.3%, p<0.01). Conclusions: We identified infertile men with testicular failure had hormonal changes characterized by a decreased serum testosterone to estradiol ratio. The ratio can be corrected with aromatase inhibitor, resulting in a significant improvement in semen parameters.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.10.1-10.7
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• 2012

Objectives: In recent years, a number of structurally diverse Histone deacetylase (HDAC) inhibitors have been identified and these HDAC inhibitors induce growth arrest, differentiation and/or apoptosis of cancer cells in vitro and in vivo. This study aimed at investigating the antitumor activity of newly synthesized HDAC inhibitor, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide (IN-2001) using human breast cancer cells. Methods: We have synthesized a new HDAC inhibitor, IN-2001, and cell proliferation inhibition assay with this chemical in estrogen receptor-positive human breast cancer MCF-7 cells. Cell cycle analysis on MCF-7 cells treated with IN-2001 was carried out by flow cytometry and gene expression was measured by RT-PCR. Results: In MCF-7 cells IN-2001 showed remarkable anti-proliferative effects in a dose- and time-dependent manner. In MCF-7 cells, IN-2001 showed a more potent growth inhibitory effect than that of suberoylanilide hydroxamic acid. These growth inhibitory effects were related to the cell cycle arrest and induction of apoptosis. IN-2001 showed accumulation of cells at $G_2$/M phase and of the sub-$G_1$ population in a time-dependent manner, representing apoptotic cells. IN-2001-mediated cell cycle arrest was associated with HDAC inhibitor-mediated induction of CDK inhibitor expression. In MCF-7 cells, IN-2001 significantly increased $p21^{WAF1}$ expression. Conclusions: In summary, cyclin-dependent kinase (CDK) induced growth inhibition, possibly through modulation of cell cycle and apoptosis regulatory proteins, such as CDK inhibitors, and cyclins. Taken together, these results provide an insight into the utility of HDAC inhibitors as a novel chemotherapeutic regime for hormone-sensitive and insensitive breast cancer.

• Korean Journal of Plant Resources
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• v.31 no.3
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• pp.218-227
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• 2018

In this study, we investigated the effect of the extracts from Vaccinium oldhamii on cell proliferation and the regulatory mechanisms of cyclin D1 protein level in human cancer cells. The branch extracts from Vaccinium oldhamii (VOB) showed higher inhibitor effect against the cell growth than leave extracts (VOL) and fruit extracts (VOF) in human colorectal cancer, breast cancer, prostate cancer, non-small lung cancer, pancreatic cancer and liver cancer cells. In addition, VOB decreased cyclin D1 level at both protein and mRNA level. MG132 treatment attenuated VOB-mediated cyclin D1 downregulation. A point mutation of threonine-286 to alanine attenuated cyclin D1 degradation by VOB. In addition, the inhibition of nuclear export by leptomycin B (LMB) attenuated cyclin D1 degradation by VOB. But, the treatment of PD98059 (ERK1/2 inhibitor), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), LiCl ($GSK3{\beta}$ inhibitor), LY294002 (PI3K inhibitor) or BAY 11-7082 ($I{\kappa}K$ inhibitor) did not affect VOB-induced cyclin D1 degradation. In conclusion, VOB induced cyclin D1 degradation through redistribution of cyclin D1 from the nucleus to cytoplasm via T286 phosphorylation of cyclin D1, which resulted in the inhibition of cancer cell proliferation.