• Archives of Plastic Surgery
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• v.33 no.1
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• pp.5-12
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• 2006

Protein tyrosine kinase(PTK), protein kinase C(PKC), oxidase, as a mediator, take a significant role in signal transduction pathway of angiogenesis. The authors utilized the inhibitors, targeting the formation of three co-enzyme in signal transduction pathway in order to quantify the suppression of abnormal vascular endothelial cell proliferation induced by DMH, to compare the level suppression in each up-regulated growth factors, CTGF, CYR61, $ITG{\beta}1$, FHL2, and to identify the relationship between abnormal cell proliferation and signal transduction pathway. Five groups were established; Control group, Group of DMH, Group of DMH-mixed Herbimycin, inhibitor of protein tyrosine kinase, Group of DMH-mixed Calphostin C, inhibitor of protein kinase C, Group Of Dmh-Mixed 10U Catalase, Inhibitor Of oxidase. The rise of vascular endothelial cell was compared by MTT assay, and four growth factors were analysed with RT-PCR method, at pre-administration, 4, 8, 12, and 24 hours after administration. In comparison of abnormal proliferation of vascular endothelial cell induced by DMH, suppression was noticed in Herbimycin and Calphostin C group, and Calphostin C group revealed higher suppression effect. Nevertheless, Catalase group did not have any suppression. In manifestation of four growth factors, Herbimycin and Calphostin C group presented similar manifestation with control group, except in $ITG{\beta}$. Catalse group had similar manifestation with DMH group in all four growth factors. Abnormal proliferation of vascular endothelial cell induced by DMH have a direct relationship with PTK and PKC, more specifically to PKC. Oxidase was confirmed not to have any relevance.

• BMB Reports
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• v.34 no.6
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• pp.517-525
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• 2001

Six renaturable protein kinases that utilize the myelin basic protein (MBP) as a substrate were activated during prolonged exposure of cardiac myocytes to okadaic acid (OA). We characterized the substrate preference and activation of these kinases, with particular emphasis on 3 novel kinases-MBPK-55, MBPK-62 and MBPK-87. The transcription factors c-Jun, Elk, ATF2, and c-Fos that are used to assess mitogen-activated protein kinase activation were all poor substrates for these three kinases. MAPKAPK2 was also not phosphorylated. In contrast, Histone IIIS was phosphorylated by MBPK-55 and MBPK-62. These protein kinases were activated in cultured cardiac fibroblasts, H9c2 cardiac myoblasts, and Cos cells. High concentrations (0.5 to $1\;{\mu}M$) of OA were essential for the activation of the protein kinases in all of the cell types examined, whereas calyculin A [an inhibitor of protein phosphatase 1 (PP1) and PP2A], cyclosporin A (a PP2B inhibitor), and an inactive OA analog all failed to activate these kinases. The high dose of okadaic acid that is required for kinase activation was also required for phosphatase inhibition, as assessed by immunoblotting whole cell lysates with anti-phosphothreonine antibodies. A variety of chemical inhibitors, including PD98059 (MEK-specific), genistein (tyrosine kinase-specific) and Bisindolylmaleimide I (protein kinase C-specific), failed to inhibit the OA activation of these kinases. Thus, MBPK-55 and MBPK-62 are also Histone IIIS kinases that are widely expressed and specifically activated upon exposure to high OA concentrations.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.211-217
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• 2000

Paxillin is a regulatory component of the complex of cytoskeletal proteins that link the actin cytoskeleton to the plasma membrane. However, the role of paxillin during smooth muscle contraction is unclear. We investigated a possible role for the membrane-associated dense plaque protein paxillin in the regulation of contraction in rat aortic vascular smooth muscle. The tyrosine phosphorylation of paxillin, which was increased by norepinephrine, reached a peak level after 1 min stimulation and then decreased with time. However, norepinephrine induced a sustained contraction that reached a steady state 30 min after application. Pretreatment with tyrphostin, an inhibitor of tyrosine kinase, inhibited the tyrosine phosphorylation of paxillin and also the contraction stimulated by norepinephrine. Both inhibitions were concentration-dependent, and the degree of correlation between them was high. These results show that, in rat aortic smooth muscle, tyrosine kinase(s) activated by norepinephrine may phosphorylate the tyrosine residues of paxillin, thereby providing a source of regulation during vascular smooth muscle contraction.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.78-78
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• 2003

Inulin, an active component of Chicorium intybus root, has been shown to stimulate the growth of bifidobacteria, and inhibit colon carcinogenesis. NO mediates a number of the host-defense functions of activated macrophages, including antimicrobial and tumoricidal activity. We examined the effect of inulin on the synthesis of NO in RAW 264.7 cells. Inulin alone had no effect, whereas inulin with IFN-ν synergistically increased the NO production and inducible NO synthase (iNOS) expression in RAW 264.7 cells. Synergy between IFN-ν and inulin was mainly dependent on inulin-induced TNF-${\alpha}$ secretion. Also, protein kinase C (PKC)-${\alpha}$ was involved in the inulin-induced NO production. Inulin-mediated NO production was inhibited by the protein tyrosine kinase (PTK) inhibitor, tyrphostin AG126. Since iNOS gene transcriptions have been shown to be under the control of the NF -$\kappa$B/Rel family of transcription factors, we assessed the effect of inulin on NF -$\kappa$B/Rel using an EMSA. Inulin produced strong induction of NF-$\kappa$B/Rel binding, whereas AP-l binding was slightly induced in RAW 264.7 cells. Inulin stimulated phosphorylation and degradation of I$\kappa$B-${\alpha}$. These results suggest that in IFN-ν-primed RAW 264.7 cells inulin might stimulate NO synthesis via activation of PKC-${\alpha}$ and PTK, resulting in the activation of NF-$\kappa$B.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2002.07a
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• pp.238-238
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• 2002

We studied whether kinase pathways are involved in TCDD-induced gene expression by treating specific kinase inhibitors ncluding MEK1 inhibitor PD98059, p38 inhibitor SB202190, PI-3 kinase inhibitor Wortmannin or LY294002 or protein tyrosine kinase inhibitor Genestein and then tested the effects of individual inhibitors on TCDD-induced gene expression of cytochromelAl gene (CYPlAl). Our results show that PD98059, MEK-1 inhibitor reduces dioxin-inducible transcription of CYPlAl. p44/p42MAPK, that is phosphorylated by Mek-1, are phosphorlylated by treatment of TCDD, peaking at lnM, 30min treatments. Overexpressions of p44/p42 MAPK dominant negative mutants suppress dioxin dependent transcription of DRE-driven reporter gene in a dose-dependent manner. Our results demonstrate that p44/p42 MAPK is essential for transcriptional activity of AHR/ARNT heterodimer. We found that PD98059 dose-dependently blocks TCDD-induced DRE binding of the AHR/ARNT heterodimer, thereby it reduces TCDD-induced gene expression. Therefore, our results indicate that Mek-1/p44/p42 MAPK pathway is involved in TCDD-induced gene expression, [This study was supported by a grant from Korean Research Foundation Grant (X01529)to H. Park]

• Biomolecules & Therapeutics
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• v.29 no.1
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• pp.41-51
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• 2021

Src family kinases (SFKs), an important group of non-receptor tyrosine kinases, are suggested to be excessively activated during various types of tissue fibrosis. The present study investigated the effect of KF-1607, an orally active and a newly synthesized Src kinase inhibitor (SKI) with proposed low toxicity, in preventing the progression of renal interstitial fibrosis. Unilateral ureteral obstruction (UUO) surgery was performed in 6-week-old male C57BL/6 mice to induce renal interstitial fibrosis. Either KF-1607 (30 mg/kg, oral gavage) or PP2 (2 mg/kg, intraperitoneal injection), a common experimental SKI, was administered to mice for seven days, started one day prior to surgery. UUO injury-induced SFK expression, including Src, Fyn, and Lyn kinase. SFK inhibition by KF-1607 prevented the progression of tubular injury in UUO mice, as indicated by decreases in albuminuria, urinary KIM-1 excretion, and kidney NGAL protein expression. Renal tubulointerstitial fibrosis was attenuated in response to KF-1607, as shown by decreases in α-SMA, collagen I and IV protein expression, along with reduced Masson's trichrome and collagen-I staining in kidneys. KF-1607 also inhibited inflammation in the UUO kidney, as exhibited by reductions in F4/80 positive-staining and protein expression of p-NFκB and ICAM. Importantly, the observed effects of KF-1607 were similar to those of PP2. A new pan Src kinase inhibitor, KF-1607, is a potential pharmaceutical agent to prevent the progression of renal interstitial fibrosis.

• BMB Reports
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• v.47 no.1
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• pp.45-50
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• 2014

Aspirin has been demonstrated to be effective in inhibiting COX-2 and $PGE_2$ in Alveolar macrophages (AMs). However, the mechanisms have not been fully understood. In the present study, we found that pretreatment with aspirin inhibited LPS-induced COX-2 and$PGE_2$ upregulation, $I{\kappa}B{\alpha}$ degradation, NF-${\kappa}B$ activation and the increase of PKC activity, but elevated LPS-induced the decrease of PTP activity. The PKC inhibitor calphostin C dramatically reduced the COX-2 mRNA and $PGE_2$ levels, but the PTP inhibitor peroxovanadium (POV) significantly increased the COX-2 mRNA and$PGE_2$ levels. Furthermore, the PTP inhibitor mitigated the inhibitory effect of aspirin on COX-2 and$PGE_2$ upregulation and NF-${\kappa}B$ activation, whereas the PKC inhibitor enhanced the inhibitory effects of aspirin on the production of COX-2 and$PGE_2$. Our data indicate a novel mechanism by which aspirin acts as a potent anti-inflammatory agent in alveolus macrophages and ALI.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.225.2-225
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• 1998

No Abstract, See Full Text

• Molecules and Cells
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• v.28 no.3
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• pp.167-174
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• 2009

Genistein has been reported to potentiate glucose-stimulated insulin secretion (GSIS). Inhibitory activity on tyrosine kinase or activation of protein kinase A (PKA) was shown to play a role in the genistein-induced potentiation effect on GSIS. The aim of the present study was to elucidate the mechanism of genistein-induced potentiation of insulin secretion. Genistein augmented insulin secretion in INS-1 cells stimulated by various energygenerating nutrients such as glucose, pyruvate, or leucine/glutamine (Leu/Gln), but not the secretion stimulated by depolarizing agents such as KCl and tolbutamide, or $Ca^{2+}$ channel opener Bay K8644. Genistein at a concentration of $50{\mu}M$ showed a maximum potentiation effect on Leu/Gln-stimulated insulin secretion, but this was not sufficient to inhibit the activity of tyrosine kinase. Inhibitor studies as well as immunoblotting analysis demonstrated that activation of PKA was little involved in genistein-induced potentiation of Leu/Gln-stimulated insulin secretion. On the other hand, all the inhibitors of $Ca^{2+}$/calmodulin kinase II tested, significantly diminished genistein-induced potentiation. Genistein also elevated the levels of $[Ca^{2+}]_i$ and phospho-CaMK II. Furthermore, genistein augmented Leu/Gln-stimulated insulin secretion in CaMK II-overexpressing INS-1 cells. These data suggest that the activation of CaMK II played a role in genistein-induced potentiation of insulin secretion.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.200-206
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• 2007

Pharmacophore models for lymphocyte-specific protein tyrosine kinase (P56 LCK) were developed using CATALYST HypoGen with a training set comprising of 25 different P56 LCK inhibitors. The best quantitative pharmacophore hypothesis comprises of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic aliphatic and one ring aromatic features with correlation coefficient of 0.941, root mean square deviation (RMSD) of 0.933 and cost difference (null cost-total cost) of 66.23. The pharmacophore model was validated by two methods and the validated model was further used to search databases for new compounds with good estimated LCK inhibitory activity. These compounds were evaluated for their binding properties at the active site by molecular docking studies using GOLD software. The compounds with good estimated activity and docking scores were evaluated for physiological properties based on Lipinski's rules. Finally 68 compounds satisfied all the properties required to be a successful inhibitor candidate.