• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.181-185
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• 2001

The naturally occurring chemical indole-3-carbinol (13C), found in vegetables of the Brassica genus, is a promising anticancer agent that was shown previ- ously to induce a Gl cell cycle arrest of human breast cancer cell lines, independent of estrogen receptor signaling. The anticancer activity of 13C and the possible mechanisms of its action were explored in a human hepatocellular carcinoma cell line, HepG2. Treatment of HepG2 cells with 13C suppressed the growth of the cells. The growth sup- pression caused by 13C ($IC_{50}$/: 444$\mu$M) was found to be partially due to its ability to stop the cell cycle in HepG2 cells. Western blot analysis for the Gl phase artiest demonstrated that the expression-levels of cyclin-dependent kinase (Cdk4, Cdk6) and cyclic D were reduced strongly after treatment of Hep72 cells with 13C (4007M) for 24- 72 hrs. Furthermore, I3C selectively abolished the expression of Cdk6 in a dose- and time-dependent manner, and accordingly, inhibited the phosphorylation of retinoblastoma. Interestingly, after the HepG2 cells reached their max- imal growth arrest, the level of the p21, a well-known Cdk inhibitor, increased significantly. Therefore, it could be considered that the Gl arrest of HepG2 cells treated with 13C was due to the indirect inhibition of Cdk4/6 activities by p21 Western blot analysis for G2/M phase arrest of demonstrated the levels of Cdc2 and cyclin Bl werer reduced dramatically after the treatment of HepG2 cells with 13C ($40\mu$M) for 24-72 hrs. flow cytometry of propidium iodide-stained HepG2 cells revealed that 13C induces a Gl (53%,72hr incubation) and G2 (25%,24hr incubation) cell cycle arrest. Thus, our observations have uncovered a previously undefined antiproliferative pathway for r3C that implicates Cdk4/6 and Cdc2 as a target for cell cycle control in human HepG2 cells. However, the 13C-medi- ated cell cycle arrest and repression of Cdk4/6 production did not affect the apoptotic induction of HepG2 cell.

• International Journal of Oral Biology
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• v.33 no.1
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• pp.33-43
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• 2008

In the process of bone remodeling, mineral phase of bone is dissolved by osteoclasts, resulting in elevation of calcium concentration in micro-environment. This study was performed to explore the effect of high extracellular calcium ($Ca{^{2+}}_e$) on mineralized nodule formation and on the expression of progressive ankylosis (Ank), plasma cell membrane glycoprotein-1 (PC-1) and osteopontin by primary cultured mouse calvarial cells. Osteoblastic differentiation and mineralized nodule formation was induced by culture of mouse calvarial cells in osteoblast differentiation medium containing ascorbic acid and ${\beta}$-glycerophosphate. Although Ank, PC-1 and osteopontin are well known inhibitors of mineralization, expression of these genes were induced at the later stage of osteoblast differentiation during when expression of osteocalcin, a late marker gene of osteoblast differentiation, was induced and mineralization was actively progressing. High $Ca{^{2+}}_e$(10 mM) treatment highly enhanced mRNA expression of Ank, PC-1 and osteopontin in the late stage of osteoblast differentiation but not in the early stage. Inhibition of p44/42 MAPK activation but not that of protein kinase C suppressed high $Ca{^{2+}}_{e^-}$induced expression of Ank, PC-1 and osteopontin. When high $Ca{^{2+}}_e$(5 mM or 10 mM) was present in culture medium during when mineral deposition was actively progressing, matrix calcifiation was significantly increased by high $Ca{^{2+}}_e$. This stimulatory effect was abolished by pyrophosphate (5 mM) or levamisole (0.1-0.5 mM), an alkaline phosphatase inhibitor. In addition, probenecid (2mM), an inhibitor of Ank, suppressed matrix calcification in both control and high $Ca{^{2+}}_{e^-}$treated group, suggesting the possible role of Ank in matrix calcification by osteoblasts. Taken together, these results showed that high $Ca{^{2+}}_e$ stimulates expression of Ank, PC-1 and osteopontin as well as matrix calcification in late differentiation stage of osteoblasts and that p44/42 MAPK activation is involved in high $Ca{^{2+}}_{e^-}$induced expression of Ank, PC-1 and osteopontin.

• The Journal of Korean Obstetrics and Gynecology
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• v.33 no.3
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• pp.40-59
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• 2020

Objectives: The purpose of this study was to investigate the anti-inflammatory effects of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos in vitro, which has been frequently used in inflammatory diseases. Methods: In this experiment, the anti-inflammatory effects of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos were evaluated by checking the following substances of LPS-activated Raw264.7 cell: Prostaglandin E₂ (PGE₂), Nitric oxide (NO), Cyclooxygenase-2 (COX-2), inducible Nitric oxide synthase (iNOS), Interlukine-1β (IL-1β), Interlukine-6 (IL-6), Tumor necrosis factor-α (TNF-α), mitogen-activated protein kinase (MAPK), Inhibitor of kappa B-α (IκBα), Nuclear factor kappa B (NF-κB). And additionally measured reactive oxygen species (ROS) and free radicals to check the antioxidant effect of ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos which affect inflammatory responses. Results: As a result of measuring anti-inflammatory efficacy, PGE2, NO, IL-1β, IL-6, TNF-α production amounts were reduced in the ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos groups compared with the control group, and decreased the amount of COX-2 mRNA, iNOS mRNA gene expression. Expression of MAPK (ERK, JNK, p38) pathway was decreased. Expression of IκBα was increased and NF-κB was decreased. It is demonstrated that ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos, by reducing NF-κB, regulate the expression of the inflammatory genes and reduce the inflammatory mediators. Ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos also decreased ROS production and free radicals, which shown to have antioxidant efficacy and influence anti-inflammatory effects. Conclusions: These data suggest that ethanol extracts from Forsythia viridissima Lindley's fructus and Lonicera japonica Thunberg's flos can be used to treat various inflammatory diseases.

• BMB Reports
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• v.32 no.4
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• pp.339-344
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• 1999

We studied the effects of ginsenosides in immature rats based upon the previous results that ginseng has a suppressive or anticonvulsive activity. To examine the suppressive effect of ginsenosides on kainic acid-induced seizures, the severities and frequencies were observed for 4 h after injection of kainic acid (KA; i.p., 2 mg/kg b.w.) using 10-day-old male Sprague-Dawley rats ($22{\pm}2\;g$). Protopanaxadiol saponins such as ginsenoside-Rb1 (Rb1), ginsenoside-Rb2 (Rb2), ginsenoside-Rc (Rc), and ginsenoside-Rd(Rd) generally reduced the seizure activities while protopanaxatriol saponins such as ginsenoside-Rg1 (Rg1) and ginsenoside-Re (Re) rather increased stereotypic "paddling-like" movements. When vinyl-GABA (v-G) was injected together with Rb1 or Rc, KA-induced seizure severities were additionally reduced only by the injection of Rc, but not by Rb1. The level of gamma isozyme of protein kinase C (PKC-${\gamma}$) in the hippocampus increased about three times as much as that of normal rats at 4 h after KA injection. The increased level of PCK-${\gamma}$ by KA was significantly reduced to about 35% by the coinjection with v-G alone, but it was not changed by v-G together with Rb1 or Rc. The increased level of PKC-${\gamma}$ at 4 h after injection of KA was not consistent with the reduction of seizure severities between Rb1 and Rc. These results suggest that Rc and Rb1 may reduce seizure severity independent of PKC-${\gamma}$ levels, and Rc may additionally act with v-G regarding the GABA metabolism during the stage of KA-induced seizures in the immature rats.

• Journal of Acupuncture Research
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• v.27 no.6
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• pp.31-42
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• 2010

Objectives : The aim of this study was to investigate the anti-obesity potential and mechanisms of action of Rhizoma Atractylodis(RA) herbal acupuncture in high fat diet- induced obese ICR mice. Methods : Sample solutions for herbal acupuncture were prepared from the Rhizoma Atractylodis water extract powder at concentration of 150mg/kg and 300mg/kg with distilled water. Five week-old ICR mice acclimatized to the laboratory environment for 1 week were allocated into four groups: regular diet group (RD), high fat diet group(HFD), groups fed HFD with 150mg/kg RA herbal acupuncture treatment (RAE 150) and with 300mg/kg RA herbal acupuncture treatment(RAE 300). Herbal acupuncture groups were injected with either 150mg/kg or 300mg/kg of Rhizoma Atractylodis(RA) subcutaneously onto both Sinsu($BL_{23}$) alternately on the same time everyday for 30days. Body weight, gross appearance of epididymal fat area, blood glucose, insulin, insulin resistance(HOMA-IR), non-esterified fatty acid, cholesterol, triglyceride, AST, ALT, histological analysis of white adipose tissue, gene expression responsible for adipocyte differentiation and AMPK activation were analyzed. Results : RA herbal acupuncture inhibited the development of weight gain, hyperglycemia, hyperinsulinemia, hyperlipidemia, increases of AST and ALT, and the enlargement of fat cell size induced by HFD. Also, RA herbal acupuncture inhibited the expression of PPAR-${\gamma}$, C/$EBP{\alpha}$, aP2, LPL, FAS, SCD-1 and enhanced the activation of AMP-activated protein kinase. Conclusions : The results of this study demonstrate that RA herbal acupuncture can exert the anti-obesity effect and it is partially mediated by activation of AMPK and inhibition of the gene expressions responsible for adipocyte differentiation. Further studies will be required to ascertain the nti-obesity effect and mechanisms of action of RA herbal acupuncture in animal models and human for aclinical application.

• BMB Reports
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• v.34 no.3
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• pp.237-243
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• 2001

Taxol, a natural product extracted from the Taxus brevifolia, is known to have significant anti-tumor activities against many common cancers, including ovarian and breast cancers. Despite the pronounced anti-tumor activity of this compound, its poor solubility in aqueous solutions hampers its clinical applications. We studied the anticancer mechanisms of the water-soluble taxol diethylenetriamine pentaacetate (DTPA) used for radiolabeling, and compared it to that of taxol. In vitro cytotoxicities of taxol and taxol-DTPA conjugate were tested in HT29 human colorectal cancer cells by the MTT method. As the result, the $IC_{50}$ value of the taxol-DTPA conjugate was about three fold higher than that of taxol. When analyzed by an agarose gel electrophoresis, the DNA ladders became evident after the incubation of cells with the taxol-DTPA conjugate for 24 h. We also found morphological changes of the cells undergoing apoptosis with electron microscopy Next, we examined the signal pathway of taxol-DTPA conjugate-induced apoptosis in HT29 cells. The activation of extracellular signal-regulated protein kinase (ERK1/2) occurred at 10, 30, 60 and 120 min after 200 nM taxol-DTPA conjugate treatment. The pretreatment of the MEK inhibitor (PD98059) completely blocked the taxol-DTPA conjugate-induced ERK1/2 activation. The activated ERK1/2 translocated into the nucleus at the same time and phosphorylated its transcriptional factor, c-Jun. These results suggest that the taxol-DTPA conjugate has an apoptotic activity in HT29 cells, and that its proapoptic activity might be related with the signal transduction via ERK1/2 and c-Jun similar to that of taxol.

• Parasites, Hosts and Diseases
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• v.56 no.2
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• pp.135-145
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• 2018

Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, $CK2{\beta}$, VEGF, GCL, GST and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.272-277
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• 2007

The physiological responses of microorganisms to specific nutrient limitation can be regulated at the transcriptional levels. In this study, in order to develop the Pichia pastoris-derived promoter inducible by nutrient-limited condition, we constructed cDNA libraries using RT-PCR of total RNA from P. pastoris in steady-states of phosphate-limited chemostat with different dilution rates. Various genes were detected from cDNA library. Among these genes, the gene encoding putative sodium/phosphate ($Na^+$/Pi) symporter (NPS), high affinity transporter of phosphate, was detected. It was observed that expression of NPS increased in a manner specific to phosphate-limited condition through Northern blot. Therefore, it is thought that the promoter from NPS gene may have the potential as auto-inducible promoter by phosphate-limited culture condition without inducer.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.405-413
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• 2011

This study was designed to elucidate high-$K^+$ induced response of circular and longitudinal smooth muscle from human gastric corpus using isometric contraction. Contraction from circular and longitudinal muscle stripes of gastric corpus greater curvature and lesser curvature were compared. Circular smooth muscle from corpus greater curvature showed high $K^+$ (50 mM)-induced tonic contraction. On the contrary, however, longitudinal smooth muscle strips showed high $K^+$ (50 mM)-induced sustained relaxation. To find out the reason for the discrepancy we tested several relaxation mechanisms. Protein kinase blockers like KT5720, PKA inhibitor, and KT5823, PKG inhibitor, did not affect high $K^+$-induced relaxation. $K^+$ channel blockers like tetraethylammonium (TEA), apamin (APA), glibenclamide (Glib) and barium ($Ba^{2+}$) also had no effect. However, N(G)-nitro-L-arginine (L-NNA) and 1H-(1,2,4) oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC) and 4-AP (4-aminopyridine), voltage-dependent $K^+$ channel (KV) blocker, inhibited high $K^+$ -induced relaxation, hence reversing to tonic contraction. High $K^+$-induced relaxation was observed in gastric corpus of human stomach, but only in the longitudinal muscles from greater curvature not lesser curvature. L-NNA, ODQ and KV channel blocker sensitive high $K^+$-induced relaxation in longitudinal muscle of higher portion of corpus was also observed. These results suggest that longitudinal smooth muscle from greater curvature of gastric corpus produced high $K^+$-induced relaxation which was activated by NO/sGC pathway and by $K_V$ channel dependent mechanism.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.910-910
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• 2005