• Title, Summary, Keyword: protein kinase inhibitors

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Action of Phospholipase $A_2$in Histamine Release from Mast Cells (비만세포에서 Histamine유리에 관여하는 Phospholipase $A_2$의 작용)

  • 이윤혜;이승준;서무현;장용운;윤정이
    • YAKHAK HOEJI
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    • v.45 no.3
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    • pp.287-292
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    • 2001
  • To investigate whether phospholipase $A_2$pathway is involved in histamine release of rat peritoneal mast cells, we measured histamine release in the presence of various enzyme inhibitors involved in eicosanoid pathway, such as phospholipase $A_2$, cyclooxygenase and lipoxygenase. Phospholipase $A_2$inhibitors, manoalide and OPC, significantly inhibited histamine release induced by 100 $\mu$M ATP and 1$\mu$g/ml compound 48/80. Cyclooxygenase inhibitors, ibuprofen and indomethacin, significantly inhibited ATP-induced histamine release and lipoxygenase inhibitors, baicalein and caffeic acid, also significantly inhibited. To investigate the involvement of protein kinase in ATP- and compound 48/80-induced histamine release, we observed effects of protein kinase inhibitors on histamine release. Bisindolmaleimide (protein kinase C antagonist) dose-dependently inhibited both ATP and compound 48/80-induced histamine release. Tyrosine kinase inhibitors (methyl 2,5-dihydroxy cinnamate and genistein) dose-dependently inhibited ATP and compound 48/80-induced histamine release. Protein kinase C and tyrosine kinase seem to be involved in histamine release induced by ATP and compound 48/80. These results suggest that phospholipase $A_2$pathway as well as protein kinase C and tyrosine kinase are involved in histamine release of rat peritoneal mast cells by ATP and compound 48/80.

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Effects of Protein Kinase Inhibitors on In Vitro Protein Phosphorylation and on Secondary Metabolism and Morphogenesis in Streptomyces coelicolor A3(2)

  • Hong, Soon-Kwang;Sueharu, Horinouchi
    • Journal of Microbiology and Biotechnology
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    • v.8 no.4
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    • pp.325-332
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    • 1998
  • In vitro phosphorylation experiments with a cell extract of Streptomyces coelicolor A3(2) M130 in the presence of ${\gamma}-[^32P]$]ATP revealed the presence of multiple phosphorylated proteins, including the AfsR/AfsK kinases which control the biosynthesis of A-factor, actinorhodin, and undecylprodigiosin. Phosphorylation of AfsR by a cell extract as an AfsK source was significantly inhibited by Ser/Thr protein kinase inhibitors, staurosporine and K-252a, at concentrations giving 50% inhibition ($IC_50$) of $1{\mu}M\;and\;0.1{\mu}M$, respectively. Further in vitro experiments with the cell extracts showed that phosphorylation of multiple proteins was inhibited by various protein kinase inhibitors with different inhibitory profiles. Manganese and calcium ions in the reaction mixture also modulate phosphorylation of multiple proteins. Manganese at 10 mM greatly enhanced the phosphorylation and partially circumvented the inhibition caused by staurosporine and K-252a. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, which are known as tyrosine kinase inhibitors, did not show any significant inhibition of AfsR phosphorylation. Consistent with the in vitro effect of the kinase inhibitors, they inhibited aerial mycelium formation and pigmented antibiotic production on solid media. On the contrary, when assayed in liquid culture, the amount of actinorhodin produced was increased by staurosporine and K-252a and greatly decreased by manganese. All of these data clearly show that the genus Streptomyces possesses several protein kinases of eukaryotic types which are involved in the regulatory network for morphogenesis and secondary metabolism.

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The Role of Protein Kinase C and Protein Tyrosine Kinase in the Signal Transduction Pathway of Stimulus Induced by Endotoxin in Peripheral Blood Monocyte (말초혈액 단핵구에 대한 내독소 자극의 신호 전달에서 Protein Kinase C와 Protein Tyrosine Kinase의 역할)

  • Kim, Jae-Yeol;Park, Jae-Suk;Lee, Gwi-Lae;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.2
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    • pp.338-348
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    • 1997
  • Background : Endotoxin, the component of outermembrane of gram negative organism, plays an important role in the initiation and amplification of inflammatory reaction by its effects on inflammatory cells. Until recently, there have been continuing efforts to delinate the mechanisms of the signal trasduction pathway of endotoxin stimuli on inflammatory cells. By uncovering the mechanisms of signal transduction pathway of endotoxin stimuli, we can expect to have tools to control the excessive inflammatory responses which sometimes may be fatal to the involved host. It was generally accepted that endotoxin exerts its inflammatory effects through inflammatory cytokines that are produced by endotoxin-stimulated inflammatory cells and there were some reports on the importance of protein kinase C and protein tyrosine kinase activation in the production of inflammatory cytokines by endotoxin So we evaluated the effect of pretreatment of protein kinase C inhibitors (H7, Staurosporin) and protein tyrosine kinase inhibitors(Herbimycin, Genistein) on the endotoxin-stimulated cytokines(IL-8 & TNF-$\alpha$) mRNA expression. Method : Peripheral blood monocytes were isolated from healthy volunteers by Ficoll-Hypaque density gradient method and purified by adhesion to 60mm Petri dishes. Endotoxin(LPS 100ng/ml) was added to each dishes except one control dish, and each endotoxin-stimulated dishes was preincubated with H7, Staurosporin(protein kinase C inhibitor), Herbimycin or Genistein(protein tyrosine kinase inhibitor) respectively except one dish. Four hours later the endotoxin stimulation, total RNA was extracted and Northern blot analysis for IL-8 mRNA and TNF-$\alpha$ mRNA was done. Result : Endotoxin stimulation increased the expression of IL-8 mRNA and TNF-$\alpha$ mRNA expression in human peripheral blood monocyte as expected and the stimulatory effect of endotoxin on TNF-$\alpha$ mRNA expression was inhibited by protein kinase C inhibitors(H7, Staurosporin) and protein tyrosine kinase inhibitors (Herbimycin, Genistein). The inhibitory effect of each drugs was increased with increasing concentration. The stimulatory effect of endotoxin on IL-8 mRNA was also inhibited by H7 and protein tyrosine kinase inhibitors (Herbimycin, Genistein) dose-dependently but not by Staurosporin. Conclusion : Protein kinase C and protein tyrosine kinase are involved in the endotoxin induced signal transduction pathway in human peripheral blood monocyte.

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Molecular Basis of Drug Resistance: Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors and Anaplastic Lymphoma Kinase Inhibitors

  • Yang, Sei-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.75 no.5
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    • pp.188-198
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    • 2013
  • Over the past decade, several kinase inhibitors have been approved based on their clinical benefit in cancer patients. Unfortunately, in many cases, patients develop resistance to these agents via secondary mutations and alternative mechanisms. To date, several major mechanisms of acquired resistance, such as secondary mutation of the epidermal growth factor receptor (EGFR) gene, amplification of the MET gene and overexpression of hepatocyte growth factor, have been reported. This review describes the recent findings on the mechanisms of primary and acquired resistance to EGFR tyrosine kinase inhibitors and acquired resistance to anaplastic lymphoma kinase inhibitors, primarily focusing on non-small cell lung carcinoma.

SB202190- and SB203580-Sensitive p38 Mitogen-Activated Protein Kinase Positively Regulates Heat Shock- and Amino Acid Analog-Induced Heat Shock Protein Expression

  • Kim, Sun-Hee;Han, Song-Iy;Oh, Su-Young;Seo, Myoung-Suk;Park, Hye-Gyeong;Kang, Ho-Sung
    • Biomedical Science Letters
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    • v.9 no.2
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    • pp.59-65
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    • 2003
  • When cells are exposed to proteotoxic stresses such as heat shock, amino acid analogs, and heavy metals, they increase the synthesis of the heat shock proteins (HSPs) by activating the heat shock transcription factor 1 (HSF1), whose activity is controlled via multiple steps including homotrimerization, nuclear translocation, DNA binding, and hyperphosphorylation. Under unstressed conditions, the HSF1 activity is repressed through its constitutive phosphorylation by glycogen synthase kinase 3$\beta$ (GSK3$\beta$), extracellular regulated kinase 1/2 (ERK1/2), and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). However, the protein kinase (s) responsible for HSF1 hyperphosphorylation and activation is not yet identified. In the present study, we observed that profile of p38 mitogen-activated protein kinase (p38MAPK) activation in response to heat shock was very similar to those of HSF1 hyperphosphorylation and nuclear translocation. Therefore, we investigated whether p38MAPK is involved in the heat shock-induced HSF1 activation and HSP expression. Here we show that the p38MAPK inhibitors, SB202190 and SB203580, but not other inhibitors including the MEK1/2 inhibitor PD98059 and the PI3-K inhibitor LY294002 and wortmannin, suppress HSF1 hyperphosphorylation in response to heat shock and L-azetidine 2-carboxylic acid (Azc), but not to heavy metals. Furthermore, heat shock-induced HSF1-DNA binding and HSP72 expression was specifically prevented by the p38MAPK inhibitors, but not by the MEK1/2 inhibitor and the PI3-K inhibitors. These results suggest that SB202190- and SB203580-sensitive p38MAPK may positively regulate HSP gene regulation in response to heat shock and amino acid analogs.

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Direct effect of protein kinase C inhibitors on cardiovascular ion channels

  • Son, Youn-Kyoung;Hong, Da-Hye;Kim, Dae-Joong;Firth, Amy L.;Park, Won-Sun
    • BMB Reports
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    • v.44 no.9
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    • pp.559-565
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    • 2011
  • Protein kinase C (PKC) is a central enzyme that modulates numerous biological functions. For this reason, specific PKC inhibitors/activators are required to study PKC-related signaling mechanisms. To date, although many PKC inhibitors have been developed, they are limited by poor selectivity and nonspecificity. In this review, we focus on the nonspecific actions of PKC inhibitors on cardiovascular ion channels in addition to their PKC-inhibiting functions. The aim of this paper is to urge caution when using PKC inhibitors to block PKC function. This information may help to better understand PKC-related physiological/biochemical studies.

Regulation of the Contraction Induced by Emptying of Intracellular $Ca^{2+}$ Stores in Cat Gastric Smooth Muscle

  • Baek, Hye-Jung;Sim, Sang-Soo;Rhie, Duck-Joo;Yoon, Shin-Hee;Hahn, Sang-June;Jo, Yang-Hyeok;Kim, Myung-Suk
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.2
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    • pp.113-120
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    • 2000
  • To investigate the mechanism of smooth muscle contraction induced by emptying of intracellular $Ca^{2+}$ stores, we measured isometric contraction and $^{45}Ca^{2+}$ influx. $CaCl_2$ increased $Ca^{2+}$ store emptying- induced contraction in dose-dependent manner, but phospholipase C activity was not affected by the $Ca^{2+}$ store emptying-induced contraction. The contraction was inhibited by voltage-dependent $Ca^{2+}$ channel antagonists dose dependently, but not by TMB-8 (intracellular $Ca^{2+}$ release blocker). Both PKC inhibitors (H-7 and staurosporine) and tyrosine kinase inhibitors (genistein and methyl 2,5-dihydroxycinnamic acid) significantly inhibited the contraction, but calmodulin antagonists (W-7 and trifluoperazine) had no inhibitory effect on the contraction. The combined inhibitory effects of protein kinase inhibitors, H-7 and genistein, together with verapamil were greater than that of each one alone. In $Ca^{2+}$ store-emptied condition, $^{45}Ca^{2+}$ influx was significantly inhibited by verapamil, H-7 or genistein but not by trifluoperazine. However combined inhibitory effects of protein kinase inhibitors, H-7 and genistein, together with verapamil were not observed. Therefore, this kinase pathway may modulate the sensitivity of contractile protein. These results suggest that contraction induced by emptying of intracellular $Ca^{2+}$ stores was mediated by influx of extracellular $Ca^{2+}$ through voltage-dependent $Ca^{2+}$ channel, also protein kinase C and/or tyrosine kinase pathway modulates the $Ca^{2+}$ sensitivity of contractile protein.

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Alteration of the Activated Responses in Platelet-Activating Factor-Stimulated Neutrophils by Protein Kinase Inhibitors (Protein Kinase 억제제 첨가 후 Platelet-Activating Factor에 의하여 자극된 호중구반응의 변경)

  • Lee, Kang-Kun;Ko, Ji-Young;Ham, Dong-Suk;Shin, Yong-Kyoo;Lee, Chung-Soo
    • The Korean Journal of Pharmacology
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    • v.32 no.1
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    • pp.103-112
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    • 1996
  • Roles of protein kinase C and protein tyrosine kinase in the activation of neutrophil respiratory burst, degranulation and elevation of cytosolic $Ca^{2+}$ in platelet-activating factor (PAF)-stimulated neutrophils were investigated. Superoxide and $H_2O_2$ production and myeloperoxidase and acid phosphatase release in PAF-stimulated neutrophils were inhibited by protein kinase C inhibitors, staurosporine and H-7 and protein tyrosine kinase inhibitors, genistein and tyrphostin. The PAF-induced elevation of $[Ca^{2+}]_i$ in neutrophils was inhibited by staurosporine, genistein and methyl-2,5-dihydroxycinnamate. Staurosporine inhibited both intracellular $Ca^{2+}$ release and $Mn^{2+}$ influx in PAF-stimulated neutrophils. Genistein and methyl-2,5-dihydroxycinnamate inhibited $Mn^{2+}$ influx induced by PAF, whereas their effects on intracellular $Ca^{2+}$ release were not detected. In neutrophils preactivated by PMA, the stimulatory effect of PAF on the elevation of $[Ca^{2+}]_i$ was reduced. Protein kinase C and protein tyrosine kinase may be involved in respiratory burst, lysosomal enzyme release and $Ca^{2+}$ mobilization in PAF-stimulated neutrophils. The elevation of $[Ca^{2+}]_i$ appears to be accomplished by intracullular $Ca^{2+}$ release and $Ca^{2+}$ influx which are differently regulated by protein kinases. Preactivation of protein kinase C appears to attenuate the stimulatory action of PAF on intracellular $Ca^{2+}$ mobilization.

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Descriptor-Based Profile Analysis of Kinase Inhibitors to Predict Inhibitory Activity and to Grasp Kinase Selectivity

  • Park, Hyejin;Kim, Kyeung Kyu;Kim, ChangHoon;Shin, Jae-Min;No, Kyoung Tai
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2680-2684
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    • 2013
  • Protein kinases (PKs) are an important source of drug targets, especially in oncology. With 500 or more kinases in the human genome and only few kinase inhibitors approved, kinase inhibitor discovery is becoming more and more valuable. Because the discovery of kinase inhibitors with an increased selectivity is an important therapeutic concept, many researchers have been trying to address this issue with various methodologies. Although many attempts to predict the activity and selectivity of kinase inhibitors have been made, the issue of selectivity has not yet been resolved. Here, we studied kinase selectivity by generating predictive models and analyzing their descriptors by using kinase-profiling data. The 5-fold cross-validation accuracies for the 51 models were between 72.4% and 93.7% and the ROC values for all the 51 models were over 0.7. The phylogenetic tree based on the descriptor distance is quite different from that generated on the basis of sequence alignment.

Involvement of Protein Tyrosine Kinase in Stimulated Neutrophil Responses by Sodium Fluoride

  • Chung, Ki-Kwang;Han, Eun-Sook;Lee, Chung-Soo
    • BMB Reports
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    • v.30 no.2
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    • pp.89-94
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    • 1997
  • In this study, during the activation of neutrophil responses by sodium fluoride. involvement of protein tyrosine kinase was studied. Respiratory burst lysosomal enzyme release and elevation of $[Ca^{2+}]_i$stimulated by sodium fluoride in neutrophils were inhibited by protein kinase inhibitors, genistein and tyrphostin. The inhibitory effect of genistein and tyrphostin on superoxide and $H_{2}O_{2}$ production was less than that of protein kinase C inhibitors, staurosporine and H-7. Staurosporine and H-7 had little or no effect on the release of myeloperoxidase and acid phosphatase stimulated by sodium fluoride. EGTA and verapamil inhibited the elevation of $[Ca^{2+}]_i$ evoked by sodium fluoride. The inhibitory effect of staurosporine on the elevation of $[Ca^{2+}]_i$ was less than that of genistein. Phorbol 12-myristate 13-acetate (PMA)-stimulated superoxide production, which is sensitive to staurosporine, was further enhanced by genistein, whereas the stimulatory action of PMA on myeloperoxidase release was inhibited by genistein. A pretreatment of neutrophils with PMA signifcantly attenuated sodium fluoride-evoked elevation of $[Ca^{2+}]_i$ These results suggest that protein tyrosine kinase may be involved in the activation process of neutrophil responses due to direct stimulation of guanine nucleotide regulatory proteins. In neutrophil responses, PMA-stimulated neutrophils appear to show a different type of inhibition of protein tyrosine kinase.

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