• Journal of Ginseng Research
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• 제33권1호
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• pp.26-32
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• 2009

인삼은 전통적으로 항당뇨 효과가 있는 것으로 보고되고 있다. Insulin-like growth factor (IGF)-I 역시 당뇨병성 신증의 발병 초기에 중요한 역할을 하는 것으로 알려져 있다. 이에 본 연구에서는 신장 근위세뇨관 세포에서 고포도당에 의한 IGF-I 분비에 대한 ginsenoside의 차단 효과 및 이와 관련된 신호전달계를 알아보았다. 결과는 다음과 같다. 고포도당에 의해 증가되었던 IGF-I분비 촉진 작용은 GTS, PD 및 PT 처리 시 차단되었으며, 세포 성장 작용 (세포 비대)에서도 같은 효과를 볼 수 있었다. 아울러 고포도당에 의한 cAMP 및 PKC 활성은 GTS 처리시 현저하게 차단되었으며 PD 및 PT 처리 시 역시 부분적으로 억제되는 것으로 나타났다. 이상의 결과를 볼 때 신장 근위세뇨관 세포에서 ginsenoside는 cAMP 및 PKC 활성 경로를 억제하여 고포도당에 의한 IGFs 분비 작용을 차단하는 것으로 나타났다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.318-318
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• 1994

Addition of AAF to murine splenocytes culture produced a dose-related suppression of lymphoproliferative response to lipopolysaccharide (LPS). The time course of the suppression showed that a significant inhibition was occured after a 18 hr AAF treatment. Total protein kinase C activity in splenocytes was decreased to 72% of control level after a 18 hr AAF treatment. Phosphorylation of a PKC specific 80 kDa protein was increased by LPS and AAF down-regulated LPS-induced PKC activity. LPS-induced phosphorylation of overall proteins in membrane and cytosolic fraction were also decreased by the treatment of AAF. A significant increase of PKC activity in membrane fraction was noticed within 10 min of AAF treatment compared to LPS alone and then gradually decreased to LPS level in 60 min. Meanwhile, PKC activity in cytosolic fraction was increased slightly in 10 min by the treatment of AAF and then decrease to 80% LPS level in 30 min. These results suggested that suppressive effect of AAF on LPS-induced lymphoproliferative response may be associated with the down-regulation of PKC and other susceptible kinases in spleen cells.

• Journal of Microbiology and Biotechnology
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• 제5권2호
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• pp.105-109
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• 1995

Anticancer activity of a fraction of the ethanol extract from the root of Korean angelica (Angelica gigas Nakai) was recognized in human cancer cell lines HeLa $S_3$, K-562, and Hep $G_2$. The extract blocked the phorbol ester-inducing megakaryocytic differentiation of K-562 cells, which indicated the modification of protein kinase C (PKC) activity. In vitro assay showed the activation of PKC by the extract. An effective fraction of the Angelica gigas extract, of which $R_f$ value was 0.64 in a thin layer chromatography, was a different component from those of European angelicas. The $ED_50$ value of the fraction was 8, 9, and $16\;\mu\textrm{m}/ml$ against HeLa $S_3\;Hep\;G_2$, and K-562 cells, respectively, while the fraction showed higher $ED_50$ values against normal cell lines.

• Molecules and Cells
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• 제25권4호
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• pp.504-509
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• 2008

Three G-protein-linked acetylcholine receptors (GARs) exist in the nematode C. elegans. GAR-3 is pharmacologically most similar to mammalian muscarinic acetylcholine receptors (mAChRs). We observed that carbachol stimulated ERK1/2 activation in Chinese hamster ovary (CHO) cells stably expressing GAR-3b, the predominant alternatively spliced isoform of GAR-3. This effect was substantially reduced by the phospholipase C (PLC) inhibitor U73122 and the protein kinase C (PKC) inhibitor GF109203X, implying that PLC and PKC are involved in this process. On the other hand, GAR-3b-mediated ERK1/2 activation was inhibited by treatment with forskolin, an adenylate cyclase (AC) activator. This inhibitory effect was blocked by H89, an inhibitor of cAMP-dependent protein kinase A (PKA). These results suggest that GAR-3b-mediated ERK1/2 activation is negatively regulated by cAMP through PKA. Together our data show that GAR-3b mediates ERK1/2 activation in CHO cells and that GAR-3b can couple to both stimulatory and inhibitory pathways to modulate ERK1/2.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.712-717
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• 1998

The complete nucleotide sequence of the cDNA clone encoding rat skeletal muscle myosin- binding protein H (MyBP-H) was determined and amino acid sequence was deduced from the nucleotide sequence (GenBank accession number AF077338). The full-length cDNA of 1782 base pairs(bp) contains a single open reading frame of 1454 bp encoding a rat MyBP-H protein of the predicted molecular mass 52.7kDa and includes the common consensus 1CA__TG' protein binding motif. The cDNA sequence of rat MyBP-H show 92%, 84% and 41% homology with those of mouse, human and chicken, respectively. The protein contains tandem internal motifs array (-FN III-Ig C2-FN III- Ig C2-) in the C-terminal region which resembles to the immunoglobulin superfamily C2 and fibronectin type III motifs. The amino acid sequence of the C-terminal Ig C2 was highly conserved among MyBPs family and other thick filament binding proteins, suggesting that the C-terminal Ig C2 might play an important role in its function. All proteins belonging to MyBP-H member contains `RKPS` sequence which is assumed to be cAMP- and cGMP-dependent protein kinase A phosphorylation site. Computer analysis of the primary sequence of rat MyBP-H predicted 11 protein kinase C (PKC)phosphorylation site, 7 casein kinase II (CK2) phosphorylation site and 4N-myristoylation site.

• The Korean Journal of Physiology and Pharmacology
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• 제5권4호
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• pp.287-297
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• 2001

Contraction of smooth muscle is initiated by an increase in cytosolic $Ca^{2+}$ leading to activation of $Ca^{2+}$/ calmodulin-dependnet myosin light chain (MLC) kinase and phosphorylation of MLC. The types of contraction and signaling mechanisms mediating contraction differ depending on the region. The involvement of these different mechanisms varies depending on the source of $Ca^{2+}$ and the kinetic of $Ca^{2+}$ mobilization. $Ca^{2+}$ mobilizing agonists stimulate different phospholipases $(PLC-{\beta},\;PLD\;and\;PLA_2)$ to generate one or more $Ca^{2+}$ mobilizing messengers $(IP_3\;and\;AA),$ and diacylglycerol (DAG), an activator of protein kinase C (PKC). The relative contributions of $PLC-{\beta},\;PLA_2$ and PLD to generate second messengers vary greatly between cells and types of contraction. In smooth muscle cell derived form the circular muscle layer of the intestine, preferential hydrolysis of $PIP_2$ and generation of $IP_3$ and $IP_3-dependent\;Ca^{2+}$ release initiate the contraction. In smooth muscle cells derived from longitudinal muscle layer of the intestine, preferential hydrolysis of PC by PLA2, generation of AA and AA-mediated $Ca^{2+}$ influx, cADP ribose formation and $Ca^{2+}-induced\;Ca^{2+}$ release initiate the contraction. Sustained contraction, however, in both cell types is mediated by $Ca^{2+}-independent$ mechanism involving activation of $PKC-{\varepsilon}$ by DAG derived form PLD. A functional linkage between $G_{13},$ RhoA, ROCK, $PKC-{\varepsilon},$ CPI-17 and MLC phosphorylation in sustained contraction has been implicated. Contraction of normal esophageal circular muscle (ESO) in response to acetylcholine (ACh) is linked to $M_2$ muscarinic receptors activating at least three intracellular phospholipases, i.e. phosphatidylcholine-specific phospholipase C (PC-PLC), phospholipase D (PLD) and the high molecular weight (85 kDa) cytosolic phospholipase $A_2\;(cPLA_2)$ to induce phosphatidylcholine (PC) metabolism, production of diacylglycerol (DAG) and arachidonic acid (AA), resulting in activation of a protein kinase C (PKC)-dependent pathway. In contrast, lower esophageal sphincter (LES) contraction induced by maximally effective doses of ACh is mediated by muscarinic $M_3$ receptors, linked to pertussis toxin-insensitive GTP-binding proteins of the $G_{q/11}$ type. They activate phospholipase C, which hydrolyzes phosphatidylinositol bisphosphate $(PIP_2),$ producing inositol 1, 4, 5-trisphosphate $(IP_3)$ and DAG. $IP_3$ causes release of intracellular $Ca^{2+}$ and formation of a $Ca^{2+}$-calmodulin complex, resulting in activation of myosin light chain kinase and contraction through a calmodulin-dependent pathway.

• 약학회지
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• 제41권5호
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• pp.629-637
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• 1997

Tumor necrosis factor-${alpha}$ (TNF) induced a cytotoxic response in ME-180 cervical carcinoma cells in vitro. This cytotoxic response was accompanied by a temporal series of mitogenic stimuli : increased c-fos, c-jun and jun-B expression. Depletion of protein kinase C (PKC) by exposure of ME-180 cells to 100ng/ml phorbol myristate acetate (PMA) for 24hours almost completely abolished TNF-mediated increase in these signals, indicating that a PKC-dependent pathway is involved in TNF-mediated increases in the expression of c-fos, c-jun and jun-B. Characteristics of TNF receptors after exposure to 100ng/ml PMA or 24hours were not altered, suggesting that diminished induction of these oncogenes by TNF after PMA treatment is not due to any changes at the receptor level. To examine whether a PKC-dependent pathway is involved in TNF-mediated cytotoxicity in ME-180 cells, cytotoxicity was measured after depletion of PKC. No apparent changes in cytototoxicity after PKC depletion suggest that a PKC-dependent pathway is not involved in TNF-mediated cytotoxicity. Furthermore, results from cytotoxicity tests after exposure to staurosporine (PKC inhibitor) did not show any changes in the TNF-mediated cytotoxicity, confirming that a PKC-dependent pathway is not involved in this process. These data indicate that 1) TNF induces expression of c-fos, c-jun and jun-B oncogenes via a PKC-dependent pathway and 2) PKC-dependent expression of these three oncogenes by TNF may not be involved in TNF-mediated cytotoxicity in ME-180 cells.

• Archives of Plastic Surgery
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• 제34권6호
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• pp.679-684
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• 2007

Purpose: DMH(1,2-dimethylhydrazine) has been known to induce vascular neoplasm such as malignant endothelioma in animal experiment, through induction of abnormal proliferation of HUVECs. In our previous studies, 11 types of PKC isoenzymes were determined by RT-PCR and the expression of $PKC{\alpha}$, and ${\mu}$ was more prominent than other PKC isoenzymes in the DMH-treated group. However, this result was not based on objective assessment. In this study, we further evaluated the role of $PKC{\alpha}$ on the DMH-induced abnormal proliferation of HUVECs by two different methods to identify its presence with high relevance in objective view. $PKC{\mu}$ will be investigated in further study. Methods: The study was conducted with the cultured HUVECs group(control) and the $0.75{\times}10^{-9}M$ DMH-treated group. After processing protein extraction in 0 and 24 hour, extracted protein was treated of quantitative test through BCA protein assay. In the western blot analysis, electrophoresis was performed in the order of gel preparation, sample preparation, and gel running. Electrotransfer to nitrocellulose membrane and reaction with antibody were done. Detection of $PKC{\alpha}$ was achieved through "Gel Image Analysis System". In the fluorescence immunocytochemical analysis, the grading of radiance of the intracellular $PKC{\alpha}$ particles was detected with confocal microscope after treating with primary and fluorescent secondary antibody in 0 and 24 hours. Results: The Western blot analysis showed increased $PKC{\alpha}$ expression from the specimen obtained in 24 hour of the DMH treatment group when compared to those in control group. Under confocal fluorescence microscope, the emitting radiance in the DMH treated group was brighter at 24 hours as well. Conclusion: We believe that $PKC{\alpha}$ plays a role in DMH-induced abnormal proliferation of the vascular endothelium, which may provide insights in understanding the vascular neoplasm.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1147-1150
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• 2004

Hypericin (1,3,4,6,8,13-hexahydroxy-10,11-dimethylphenanthro[1,10,9,8-opqra]perylene-7,14-dione), an antidepressant which is also known to be a potent protein kinase C (PKC) inhibitor was synthesized as a precursor for radioiodine labeling via two step reactions. Malignant glioma cells express higher PKC activity compared to untransformed glial cell. Here we report the synthesis and radioiodine labeling of hypericin as a potential brain tumor imaging radiopharmaceutical. The reference compound, 2-iodohypericin, and its radiolabelled analogues, 2-[$^{123}I$]iodohypericin and 2-[$^{124}I$]iodohypericin have been prepared by the reaction of hypericin with NaI or [$^{123}I$]NaI or [$^{124}I$]NaI. The labeling yield was 60-65% for each analogue and the optimal reaction time was 10 min. The purification and isolation of the labelled products were achieved by a reversed-phase HPLC.

• Molecules and Cells
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• 제21권2호
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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.