• Biomolecules & Therapeutics
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• v.28 no.5
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• pp.431-436
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• 2020

In this study, diclofenac, a non-steroidal anti-inflammatory drug, was investigated for its potential effect on the gene expression and production of airway MUC5AC mucin. The human respiratory epithelial NCI-H292 cells were pretreated with diclofenac for 30 min and stimulated with phorbol 12-myristate 13-acetate (PMA), for the following 24 h. The effect of diclofenac on PMA-induced nuclear factor kappa B (NF-kB) signaling pathway was also investigated. Diclofenac suppressed the production and gene expression of MUC5AC mucins, induced by PMA through the inhibition of degradation of inhibitory kappa Bα (IkBα) and NF-kB p65 nuclear translocation. These results suggest diclofenac regulates the gene expression and production of mucin through regulation of NF-kB signaling pathway, in human airway epithelial cells.

• Natural Product Sciences
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• v.25 no.3
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• pp.248-254
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• 2019

In the present study, we investigated whether quercitrin, quercetin and afzelin derived from Houttuynia cordata affect the production and gene expression of MUC5AC mucin from airway epithelial cells. Confluent NCI-H292 cells were pretreated with quercitrin, quercetin or afzelin for 30 min and then stimulated with epidermal growth factor (EGF) or phorbol 12-myristate 13-acetate (PMA) for 24 h. The MUC5AC mucin gene expression and production were measured by RT-PCR and ELISA, respectively. The results were as follows: (1) Quercitrin, quercetin and afzelin inhibited EGF- and PMA-induced MUC5AC mucin production from NCI-H292 cells; (2) The three natural products also decreased EGF- and PMA-induced MUC5AC mucin gene expression in NCI-H292 cells. These results suggest that quercitrin, quercetin and afzelin showed the regulatory effect on the steps of gene expression and production of mucin, by directly acting on airway epithelial cells.

• Environmental Analysis Health and Toxicology
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• v.15 no.3
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• pp.69-80
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• 2000

ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.185-193
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• 1997

The characteristics of $Na^+$-dependent cycloleucine uptake was investigated in OK cells with regard to substrate specificity and regulation by protein kinase C (PKC). Inhibition studies with different synthetic and natural amino acids showed a broad spectrum affinity to neutral amino acids regardless of their different side chains including branched or aromatic, indicating that the $Na^+$-dependent cycloleucine uptake in OK cells is mediated by System $B^o$ or System $B^o$-like transporter rather than the classical System A or ASC. Phorbol 12-myristate 13-acetate (PMA) and phorbol 12,13-dibutyrate, but not $4{\alpha}-PMA$ elicited a time-dependent biphasic stimulation of $Na^+$-dependent cycloleucine uptake, which produced early transient peak at 30 min and late sustained peak at 180min. Both the early and late stimulations by PMA were due to an increase in Vmax and not due to a change in Km. PKC inhibitors blocked both the early and late stimulation by PMA, while protein synthesis inhibitors blocked the late stimulation only. These results suggest the existence and regulation by PKC of System $B^o$ or System $B^o$-like broad spectrum transport system for neutral amino acids in OK cells.

• BMB Reports
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• v.28 no.6
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• pp.527-532
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• 1995

Human taurine transporter has 12 transmembrane domains and its molecular weight is 69.6 kDa. The long cytoplasmic carboxy and amino termini might function as regulatory attachment sites for other proteins. Six potential protein kinase C phosphorylation sites have been reported in human taurine transporter. In this report, we studied the effects of phorbol 12-myristate 13-acetate (PMA) and glucocorticoid hormone on taurine transportation in the RAW 264.7, mouse macrophage cell line. When the cells were incubated with $[^{3}H]taurine$ in the presence or absence of $Na^+$ ion for 40 min at $37^{\circ}C$, the [$[^{3}H]taurine$ uptake rate was 780-times higher in the $Na^{+}-containing$ buffer than in the $Na^{+}-deficient$ buffer, indicating that this cell line expresses taurine transporter protein on the cell surface. THP1, a human promonocyte cell line, also showed a similar property. The $[^{3}H]taurine$ uptake rate was not influenced by the inflammatory inducing cytokines such as interleukin-1, gamma-interferon or interleukin-1+gamma-interferon, but was decreased by the PMA in the RAW 264.7 cell line. This suggests that activation of protein kinase C inhibits taurine transporter activity directly or indirectly. The inhibition of $[^{3}H]taurine$ uptake by PMA was time-dependent. Maximal inhibition occurred in one hr stimulation with PMA Increasing the treatment time beyond one h reduced the $[^{3}H]taurine$ uptake inhibition due to the depletion or inactivation of protein kinase C. The cell line also showed concentration-dependent $[^{3}H]taurine$ uptake under PMA stimulation. The phorbol-ester caused 23% inhibition at the concentration of 1 ${\mu}m$ PMA. The inhibition was significant even at a concentration as low as 10 nM PMA The reduced $[^{3}H]taurine$ uptake could be recovered by treatment with glucocorticosteroid hormone. Dexamethasone led to recover of the reduced taurine uptake induced by phorbol-ester, recovering maximally after one hr. This may suggest that macrophage cells require higher taurine concentration in a stressed state, for the secretion of glucocorticoid hormone is increased by hypothalamo-pituitary-adrenocortical (HPA) axis activation in the blood stream.

• Journal of Life Science
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• v.13 no.6
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• pp.903-910
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• 2003

Phospholipase D (PLD) plays an important role as a signaling molecule in the activation of neutrophils. In this study, effect of nitric oxide (NO) and cGMP on the activation of PLD in human neutrophils was investigated. Sodium nitroprusside (SNP), an agent to produce NO spontaneously in cells, alone increased PLD activity and the maximal activation was obtained with 0.5 mM SNP. Dibutyryl-cAMP, an agent to increase an intracellular cAMP concentration inhibited formyl-Met-Leu-Phe (fMLP)-stimulated PLD activity but 8-bromo-cGMP (300 $\mu$M), an agent to increase an intracellular cGMP concentration did not affect basal and fMLP-stimulated PLD activity. NO-induced activation of PLD was not blocked by KT 5823, an inhibitor of cGMP-dependent protein kinase (PKG), suggesting that NO-induced PLD activation is not mediated by cGMP. NO also stimulated p38 mitogen activated protein kinase (MAPK) in human neutrophils, indicated by increased phosphorylation of p38 MAPK in Western blotting. NO-induced phosphorylation of p38 MAPK was not inhibited by KT 5823 or n-butanol. RhoA, an regulatory factor of PLD activation was trans-located from cytosolic fraction to plasma membranes by fMLP or phorbol ester, and fMLP-stimulated but not phorbol ester-stimulated translocation of RhoA was inhibited by cGMP. These results suggest that NO stimulates PLD activity through other unidentified facto.(s) than cGMP even though cGMP inhibits the artivation of RhoA.

• Journal of Aquaculture
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• v.8 no.3
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• pp.171-181
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• 1995

Gonadosomatic index (GSI) of the crucian carp (Carassius auratus) was investigated to clarify annual reproductive cycle from February in 1992 to October in 1994. The values of GSI were high with individual variation from April to July which period was coincided with the breeding season of fish. The GSI was very low in August and September, when follicular atresia developed in the ovaries. GSI value began to increase in October and reached a peak around the following March, which indicated that ovarian follicles may grow during this period. Human chorionic gonadotropin (HCG 10 IU), $17\alpha$, 20\beta-dihydroxyprogesterone\;(1-100{\mu}g/ml)$ and phorbol 12-myristate-13-acetate (TPA, protein kinase C activator, 0.1-10${\mu}M$) induced germinal vesicle breakdown (GVBD), but $4\alpha-phorbol$ 12, 13- didicanoate ($4\alpha-PDD,\;phorbol\; ester\;analogue,\;25{\mu}M$) did not induce germinal vesicle breakdown in the follicular oocytes. Prostaglandin $F_{2\alpha}$ $(0.1-10 {\mu}g/ml)$ and TPA $(0.1-10 {\mu}M$ induced ovulation of the oocytes, but $4\alpha-PDD$ $(25{\mu}M)$ did not induce ovulation of the follicles. $17\alpha-hydroxyprogesterone$ production was examined from the isolated follicles to investigate the steroid production ability in the crucian carp ovaries. HCG (1 lU, 10 lU) and forskolin (adenylate cyclase activator, 0.1-10 ${\mu}M$) stimulated $17\alpha-hydroxyprogesterone$ production. The time course of HCG (10 lU) and forskolin $(10\;{\mu}M)$ stimulated $17\alpha-hydroxyprogesterone$ production within 3 hours, the elevated levels were maintained during the rest of the culture period. The data indicates that cyclic AMP and protein kinase C may play important roles in the oocyte maturation and ovulation in crucian carp.

• BMB Reports
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• v.36 no.3
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• pp.265-268
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• 2003

Retinoic acid (RA) can transform the Golgi apparatus (GA) into a diffuse vacuolar aggregate and increase the toxicity of some immunotoxins that enter into cells by receptor-mediated endocytosis. An ultramorphological study of the RA-induced GA disruption was performed on F2000 fibroblasts. Cultures were treated with 0.11 to $30\;{\mu}M$ RA for 7 - 180 min. The endocytosis of Limax flavus agglutinin-peroxidase conjugate (LFA), and the interactions between a phorbol ester (PMA) and RA concerning GA disruption, were examined. Exposure to $0.33\;{\mu}M$ RA for 20 min transformed the GA into vacuolar aggregate. These vacuoles were not involved in endocytosis since they remained unstained after endocytosis of LFA. However, the lysosomes were involved in endocytosis, as they were strongly stained. Therefore, a RA-induced shift towards lysosomal routing of the entered LFA was presumed. Exposure to PMA made cells resistant to the Golgi-disturbing effects of RA, indicating that protein kinase C plays an important role in this process.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.153-153
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• 2001

Nitric oxide (NO) has multifaceted roles in carcinogenesis. Besides acting as an initiator, NO may also playa role in the promotional stage of tumorigenesis or neoplastic transformation. In line with this notion, our previous studies have revealed that the tumor promotor phorbol ester induces expression of inducible nitric oxide synthase (iNOS) and NO production in mouse skin.(omitted)

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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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.