• 생명과학회지
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• 제22권1호
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• pp.87-91
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• 2012

암을 유발하는 phorbol ester로 알려진 Phorbol 12-myristate 13-acetate (PMA)는 동물세포에서 신호전달 효소의 하나인 protein kinase C (PKC)를 활성화시킨다. 본 연구에서는 옥수수 일차뿌리에서 PMA가 에틸렌 생성을 통하여 굴중성 반응을 조절하는 효과를 연구하였다. PMA는 8시간 동안 $10^{-6}$ M과 $10^{-4}$ M에서 농도 의존적으로 뿌리 생장과 굴중성 반응을 촉진시켰다. 이러한 촉진 효과는 PKC의 억제제인 staurosporine (STA)에 의해 상쇄되었다. 이 결과는 굴중성 반응이 신호전달 체계에 관여하는 protein kinase C를 통하여 조절될 가능성을 제시하고 있다. 식물호르몬인 에틸렌도 뿌리 생장과 굴중성 반응에 중요한 역할을 한다고 알려져 있다. 에틸렌 생성은 $10^{-6}$ M과 $10^{-4}$ M PMA에 의하여 각각 26%와 37% 증가하였다. PMA는 또한 ACC synthase (ACS) 활성을 촉진시켰다. 또한 이 증가 효과는 STA에 의하여 상쇄되었다. 이 결과는 옥수수 뿌리에서 굴중성 반응은 에틸렌 생성을 거쳐 protein kinase를 통하여 조절될 가능성을 제시하고 있다.

• BMB Reports
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• 제55권2호
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• pp.87-91
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• 2022

Aurora kinase is a family of serine/threonine kinases intimately associated with mitotic progression and the development of human cancers. Studies have shown that aurora kinases are important for the protein kinase C (PKC)-induced invasion of colon cancer cells. Recent studies have shown that aurora kinase A promotes distant metastasis by inducing epithelial-to-mesenchymal transition (EMT) in colon cancer cells. However, the role of aurora kinase A in colon cancer metastasis remains unclear. In this study, we investigated the effects of aurora kinase A on PKC-induced cell invasion, migration, and EMT in human SW480 colon cancer cells. Treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) changed the expression levels of EMT markers, increasing α-SMA, vimentin, and MMP-9 expression and decreasing E-cadherin expression, with changes in cell morphology. TPA treatment induced EMT in a PKC-dependent manner. Moreover, the inhibition of aurora kinase A by siRNAs and inhibitors (reversine and VX-680) suppressed TPA-induced cell invasion, migration, and EMT in SW480 human colon cells. Inhibition of aurora kinase A blocked TPA-induced vimentin and MMP-9 expression, and decreased E-cadherin expression. Furthermore, the knockdown of aurora kinase A decreased the transcriptional activity of NF-κB and AP-1 in PKC-stimulated SW480 cells. These findings indicate that aurora kinase A induces migration and invasion by inducing EMT in SW480 colon cancer cells. To the best of our knowledge, this is the first study that showed aurora kinase A is a key molecule in PKC-induced metastasis in colon cancer cells.

• The Korean Journal of Physiology and Pharmacology
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• 제3권1호
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• pp.11-18
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• 1999

Nuclear factor $_{\kappa}B\;(NF-_{\kappa}B)$ activation is modulated by various protein kinases. Activation of $NF-_{\kappa}B$ is known to be important in the regulation of cell viability. The present study investigated the effect of inhibitors of protein tyrosine kinase (PTK), protein kinase C (PKC) and protein kinase A (PKA) on $NF-_{\kappa}B$ activity and the viability of bovine cerebral endothelial cells (BCECs). In serum-deprivation-induced BCEC death, low doses of $TNF{\alpha}$ showed a protective effect. $TNF{\alpha}$ induced $NF-_{\kappa}B$ activation within 4 h in serum-deprivation. PTK inhibitors (herbimycin A and genistein) and PKC inhibitor (calphostin C) prevented $NF-_{\kappa}B$ activation stimulated by $TNF{\alpha}.$ Likewise, these inhibitors prevented the protective effect of $TNF{\alpha}.$ In contrast to $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activity, basal $NF-_{\kappa}B$ activity of BCECs in media containing serum was suppressed only by calphostin C, but not by herbimycin A. As well BCEC death was also induced only by calphostin C in serum-condition. H 89, a PKA inhibitor, did not affect the basal and $TNF{\alpha}-stimulated\;NF-_{\kappa}B$ activities and the protective effect of $TNF{\alpha}$ on cell death. These data suggest that modulation of $NF-_{\kappa}B$ activation could be a possible mechanism for regulating cell viability by protein kinases in BCECs.

• 대한예방한의학회지
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• 제11권1호
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• pp.9-21
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• 2007

This study was performed to evaluate the effect of Carthami tinctorius(HH) on osteoblast function and gene expression. The osteoblasts separated from the rat calvariae were cultivated to evaluate the cell function, and MG-63 cell was also cultivated for the test of mRNA synthesis. In this experiments, cell proliferation of rat calvarial cells was increased by HH. PKC activity, intracellular free calcium level and collgen synthesis from calvarial cells were increased by HH, but not PKA activity. And the mRNA of $PLA_2$, COX-2, and $PGE_2$ synthase from MG-63 were decreased by HH, but the mRNA of prostacyclin synthase was increased. It is concluded that HH might increase the proliferation of calvarial cell resulted from augumentation of osteoblast activity and its mRNA synthesis.

• The Korean Journal of Physiology and Pharmacology
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• 제1권4호
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• pp.413-423
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• 1997

The importance of the kidney in the development of hypertension was first demonstrated by Goldblatt and his colleagues more than fifty years ago. Many hormones and other regulatory factors have been proposed to play a major role in the development of hypertension. Among these factors angiotensia II (ANG II) is closely involved in renal hypertension development since it directly regulates $Na^+$ reabsorption in the renal proximal tubule. Thus the aim of the present study was to examine signaling pathways of low dose of ANC II on the $Na^+$ uptake of primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined seum-free medium. The results were as follows: 1) $10^{-11}$ M ANG II has a significant stimulatory effect on growth as compared with control. Alkaline phosphatase exhibited significantly increased activity. However, leucine aminopeptidase and ${\gamma}-glutamyl$ transpeptidase activity were not significant as compared with control. In contrast to $10^{-11}$ M ANG II stimulated $Na^+$ uptake $(108.03{\pm}2.16% of that of control)$, $10^{-9}$ M ANG II inhibited ($92.42{\mu}2.23%$ of that of control). The stimulatory effect of ANG II on $Na^+$ uptake was amiloride-sensitive and inhibited by losartan (ANG II receptor subtype 1 antagonist) and not by PD123319 (ANG II receptor subtype 2 antagonist). 2) Pertussis toxin (PTX) alone inhibited $Na^+$ uptake by $85.52{\pm}3.52%$ of that of control. In addition, PTX pretreatment prevented the AMG II-induced stimulation of $Na^+$ uptake. 8-Bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP), forskolin, and isobutylmethylxanthine (IBMX) alone inhibited $Na^+$ uptake by $88.79{\pm}2.56,\;80.63{\pm}4.38,\;and\;84.47{\pm}4.74%$ of that of control, respectively, and prevented the ANG II-induced stimulation of $Na^+$ uptake. However, $10^{-11}$ M ANG II did not stimulate cAMP production. 3) The addition of 12-O-te-tradecanoylphorbol-13-acetate (TPA, 0.01 ng/ml) to the PTCs produced significant increase in $Na^+$ uptake ($114.43{\pm}4.05%$ of that of control). When ANG II and TPA were added together to the PTCs, there was no additive effect on $Na^+$ uptake. Staurosporine alone had no effect on $Na^+$ uptake, but led to a complete inhibition of ANG II- or TPA-induced stimulation of Na'uptake. ANG II treatment resulted in a $111.83{\mu}4.51%$ increase in total protein kinase C (PKC) activity. In conclusion, the PTX-sensitive PKC pathway is the main signaling cascade involved in the stimulatory effects of ANG II on $Na^+$ uptake in the PTCs.

• 대한한방부인과학회지
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• 제21권1호
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• pp.83-98
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• 2008

Purpose: This study was performed to determine the inhibitory effect of Soyosangagamhwajae(SYG) on melanin synthesis in B16F10 mouse melanoma cell. Methods: The Inhibitory effects of Soyosangagamhwajae(SYG) on melanin synthesis were determined by in-vitro assay. To elucidate inhibitory effects of SYG on melanin synthesis, we determined the melanin release in B16F10 cell. And to investigate the action mechanism, we assessed the gene expression of tyrosinase, TRP-1, TRP-2. PKA, $PKC{\beta}$ in B16F10 cell. Results: 1. SYG significantly inhibited melanin-release in B16F10 cell. 2. SYG significantly inhibited mushroom tyrosinase activity in vitro. 3. SYG significantly suppressed the expression of tyrosinase in B16F10 cell. 4. SYG significantly suppressed the expression of TRP-1, TRP-2 in B16F10 cell. 5. SYG significantly suppressed the expression of PKA, $PKC{\beta}$ in B16F10 cell. Conclusion: From these results, it may be concluded that SYG has the antimelanogenetic effect.

• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.139-146
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• 2001

L-type $Ca^{2+}$ channels play an important role in regulating cytosolic $Ca^{2+}$ and thereby regulating hormone secretions in neuroendocrine cells. Since hormone secretions are also regulated by various kinds of protein kinases, we investigated the role of some kinase activators and inhibitors in the regulation of the L-type $Ca^{2+}$ channel currents in rat pituitary $GH_3$ cells using the patch-clamp technique. Phorbol 12,13-dibutyrate (PDBu), a protein kinase C (PKC) activator, and vanadate, a protein tyrosine phosphatase (PTP) inhibitor, increased the $Ba^{2+}$ current through the L-type $Ca^{2+}$ channels. In contrast, bisindolylmaleimide I (BIM I), a PKC inhibitor, and genistein, a protein tyrosine kinase (PTK) inhibitor, suppressed the $Ba^{2+}$ currents. Forskolin, an adenylate cyclase activator, and isobutyl methylxanthine (IBMX), a non-specific phosphodiesterase inhibitor, reduced $Ba^{2+}$ currents. The above results show that the L-type $Ca^{2+}$ channels are activated by PKC and PTK, and inhibited by elevation of cyclic nucleotides such as cAMP. From these results, it is suggested that the regulation of hormone secretion by various kinase activity in $GH_3$ cells may be attributable, at least in part, to their effect on L-type $Ca^{2+}$ channels.

• Biomolecules & Therapeutics
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• 제24권2호
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• pp.115-122
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• 2016

Sleep, which is an essential part of human life, is modulated by neurotransmitter systems, including gamma-aminobutyric acid (GABA) and dopamine signaling. However, the mechanisms that initiate and maintain sleep remain obscure. In this study, we investigated the relationship between melatonin (MT) and dopamine D2-like receptor signaling in pentobarbital-induced sleep and the intracellular mechanisms of sleep maintenance in the cerebral cortex. In mice, pentobarbital-induced sleep was augmented by intraperitoneal administration of 30 mg/kg MT. To investigate the relationship between MT and D2-like receptors, we administered quinpirole, a D2-like receptor agonist, to MT- and pentobarbital-treated mice. Quinpirole (1 mg/kg, i.p.) increased the duration of MT-augmented sleep in mice. In addition, locomotor activity analysis showed that neither MT nor quinpirole produced sedative effects when administered alone. In order to understand the mechanisms underlying quinpirole-augmented sleep, we measured protein levels of mitogen-activated protein kinases (MAPKs) and cortical protein kinases related to MT signaling. Treatment with quinpirole or MT activated extracellular-signal-regulated kinase 1 and 2 (ERK1/2), p38 MAPK, and protein kinase C (PKC) in the cerebral cortex, while protein kinase A (PKA) activation was not altered significantly. Taken together, our results show that quinpirole increases the duration of MT-augmented sleep through ERK1/2, p38 MAPK, and PKC signaling. These findings suggest that modulation of D2-like receptors might enhance the effect of MT on sleep.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.74-79
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• 2004

Little is known about the effect of epigallocatechin-3 gallate (ESCG), a major constituent of green tea, on the expression of cyclooxygenase (COX)-2. Here, we studied the role of phospholipase D (PLD) isozymes in EGCG-induced COX-2 expression. Stimulation of human astrocytoma cells (U87) with EGCG induced formation of phosphatidylbutanol, a specific product of PLD activity, and synthesis of COX-2protein and its product, prostaglandin $E_2$ ($PGE_2$). Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed EGCG-induced COX-2 expression and $PGE_2$ synthesis. Furthermore, evidence that PLD was involved in EGCG-induced COX-2 expression w3s provided by the observations that COX-2 expression was stimulated by over-expression of PLD1 or PLD2 isozymes and treatment with phosphatidic acid(PA), and that prevention of PA dephosphorylation by 1-propranolol significantly potentiated COX-2expression Induced by EGCG. EGCG induced activation of p38 mitogen-activated protein kinase (p38MAPK), and specific Inhibition of p38 MAPK dramatically abolished EGCG-Induced PLD activation, COX-2 expression, and $PGE_2$ formation. Moreover, protein kinase C (PKC) inhibition suppressed EGCG-induced p38 MAPK activation, COX-2 expression, and $PGE_2$ accumulation. The same pathways as those obtained in the astrocytoma cells were active in primary rat astrocytes, suggesting the relevance of the findings. Collectively, our results demonstrate for the first time that PLD isozymes mediate EGCG-induced COX-2 expression through PKC and p38 in immortalized astroglial line and normal astrocyte cells.

• 대한한의학회지
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• 제19권2호
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• pp.36-49
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• 1998

HERBA SAURURI (HS) has been known to use antiinflammatory drug. To investigated the mechanism of HS-induced NO synthesis, I evaluated the ability of protein kinase C (PKC) inhibitors such as staurosporine (STSN) or polyymyxin B to block HS-induced effects. HS alone had only a small effect, whereas in combination with $rIFN-{\gamma}$, markedly increased NO synthesis in a dose dependent manner. STSN and polymyxin B decreased NO synthesis, which had been induced by $rIFN-{\gamma}$, plus HS. Furthermore, prolonged incubation of the cells with phorbol ester, which down-regulates PKC activity abolished synergistic cooperative effect of HS with $rIFN-{\gamma}$ on NO synthesis. STSN and Polymyxin B potently inhibited HS-induced $TNF-{\alpha}$ secretion by $rIFN-{\gamma}$ plus HS. However, $rIFN-{\gamma}$ plus $TNF-{\alpha}-induced$ NO synthesis was not blocked by STSN or polymyxin B. On the other hand, tyrosine kinase inhibitor, genistein, blocked the NO synthesis and $TNF-{\alpha}$ secretion by $rIFN-{\gamma}$ plus HS. In conlusion, the present results strongly suggest that the capacity of HS to increase NO synthesis from $rIFN-{\gamma}-primed$ macrophages is the result of HS-induced $TNF-{\alpha}$ secretion via the signal transduction pathway of PKC and tyrosine kinase.