• 통합자연과학논문집
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• 제7권4호
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• pp.253-259
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• 2014

Protein kinase C theta (PKC-${\theta}$) is a serine/threonine specific protein kinase. It is largely expressed in the T-cells and CD28 signaling. PKC-${\theta}$ phosphorylates diverse proteins that are involved in the various cellular signaling pathways. Activated PKC-${\theta}$ in turn activates other transcription factors that control the proliferation and differentiation of T- cells. PKC-${\theta}$ is considered to be an interesting therapeutic target due to its crucial role in the proliferation, differentiation and survival of T-cells. In the present study, we have performed ligand-based CoMFA study on a series of pyridylpyrazolopyridine derivatives as PKC-${\theta}$ inhibitors. An acceptable CoMFA model ($q^2$=0.544; ONC=4; $r^2$=0.876) was developed and validated by Bootsrapping and progressive sampling. The CoMFA contour map suggested the regions to increase the activity. Bulky substitutions in R2 position of the piperizine ring could increase the activity. Similarly positive, small substitution in the R1 position of the Pyridine ring could considerably increase the activity. Our work could assist in designing more potent PKC-${\theta}$ inhibitors of pyridylpyrazolopyridine derivatives.

• Reproductive and Developmental Biology
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• 제30권2호
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• pp.75-79
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• 2006

The developmental regulation of the preimplantation mammalian embryos is a fundamental step for preparing the implantation and it may be regulated by several autocrine and paracrine factors including platelet-activating factor. PAF improved the embryonic survival and implantation but its role during blastocyst development is still largely unknown. In this study, the effects and the possible pathway of PAF on developmental regulation of blastocyst to hatching stage were investigated. Developmental pattern in hatching embryo was a concentration-response curve showing maximal activity at 1 nM PAF, with decreasing activity at higher concentrations. $50{\mu}M$ 1-(5-isoquinolimnesulfonyl)-2-methylpiperazinme dihydrochloride (H-7), a PKC inhibitor, inhibited the progression of blastocyst to hatching embryo. In addition H-7 blocked the PAF effects on the blastocyst development. Besides tetradecanoylphorbol acetate (TPA), a PKC activator stimulated development of blastocyst to the hatching stage. These finding revealed that PAF support the blastocyst development to the hatching embryo. Also it is suggested that PAF action pathways in hatching supporting include the PKC signaling pathway.

• Animal cells and systems
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• 제4권4호
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• pp.361-366
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• 2000

In order to investigate the role of protein kinase C (PKC) in chondrogenic differentiation, we examined the localization of PKC isoforms in a limb bud micromass culture system. PKC$\alpha$ is specifically localized in the regions which would become cartilage nodules, while PKC$\lambda/l$ and $\zeta$ display widespread distribution in the whole culture. Distribution of PKC$\alpha$ change along with promotion or inhibition of chondrogenesis by lysophosphatidylcholine or phorbol 12-myristate 13-acetate. On the other hand, localization of PKC$\lambda/l$ or $\zeta$ a was not changed by the modulation of chondrogenesis. Peanut agglutinin binding protein which is associated with cell aggregation during chondrogenesis was present in the cell condensation regions and its expression in those regions was influenced by PKC activity. Expression of fibronectin and N-cadherin in the cell condensing area were also affected by modulation of PKC activity. These results suggest involvement of PKC$\alpha$ in the cell condensation, possibly through regulating expression of fibronectin and N-cadherin.

• 한국식품영양과학회지
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• 제46권1호
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• pp.140-145
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• 2017

본 연구에서는 식품으로 활용하기 위해 제조된 잣송이 추출물의 이화학적 품질 특성과 항산화 활성을 탐색하였다. 잣송이 추출물은 수분과 탄수화물이 구성성분 대부분을 차지하고 있었으며, 특히 대조군으로 사용된 매실 추출물보다 수분함량은 낮고 당 함량은 높아 유의적으로 높은 점도를 나타내었다. 또한, 갈색도와 색도는 모두 낮아 매실 추출물과 비교해 숙성 중 Maillard 갈변 반응의 정도가 상대적으로 낮았음을 시사해주었다. 잣송이 추출물은 매실 추출물보다 플라보노이드 함량은 유의적으로 다르지 않았으나 유기산 함량과 갈변도는 1/10 수준으로 유의적으로 낮았고, 총환원력은 매실 추출물의 60% 수준으로 측정되었다. 그런데도 잣송이 추출물에서 매실 추출물과 유사한 높은 금속 소거능과 라디칼 소거 활성이 관찰되었다. 또한, 잣송이 추출물 속 플라보노이드 총량보다도 많은 양인 6.6 mM quercetin과 비교할 때 2배나 높은 SOD 유사 활성을 나타내었다. 이는 잣송이 추출물에 quercetin보다 항산화 활성이 높은 플라보노이드가 존재할 가능성을 보여주며, 플라보노이드 조성에 대한 후속연구의 필요성을 시사해주었다. 본 연구는 잣송이 추출물이 제조법과 용도가 유사한 매실 추출물에 버금가는 항산화 활성을 부여하면서도 상대적으로 높은 당 함량과 낮은 유기산 함량으로 매실 추출물과는 관능적 측면에서 차별화될 수 있는 식품으로서의 활용 가능성을 보여주었다.

• Journal of Nutrition and Health
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• 제24권3호
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• pp.149-156
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• 1991

고지방식이와 총열량섭취 제한식이가 protein kinase C 활성에 미치는 영향을 규명하고자 기타 양양소 또 총열량섭취가 정확이 조절된 식이를 제조하여 투여해본 결과, protein kinase C의 활성은 본 실험에서 사용한 옥수수유의 양의 증가에 따라 cytosolic과 membrane-associated protein kinase C의 활성을 모두 증가시키는 것을 관찰 하였다. 또한 기타 영양소는 같게 투여하고 열량소만 40% 감소시킨 실험군은 대조군에 비해 양쪽의 protein kinase C가 모두 감소하는 경향을 보였다.

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.1981-1984
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• 2009

Subcellular localization of protein kinase often plays an important role in determining its activity and specificity. Protein kinase C (PKC), a family of multi-gene protein kinases has long been known to be translocated to the particular cellular compartments in response to DAG or its analog phorbol esters. We used C-terminal green fluorescent protein (GFP) fusion proteins of PKC isoforms to visualize the subcellular distribution of individual PKC isoforms. Intracellular localization of PKC-GFP proteins was monitored by fluorescence microscopy after transient transfection of PKC-GFP expression vectors in the HeLa cells. In unstimulated HeLa cells, all PKC isoforms were found to be distributed throughout the cytoplasm with a few exceptions. PKC$\theta$ was mostly localized to the Golgi, and PKC$\gamma$, PKC$\delta$ and PKC$\eta$ showed cytoplasmic distribution with Golgi localization. DAG analog TPA induced translocation of PKC-GFP to the plasma membrane. PKC$\alpha$, PKC$\eta$ and PKC$\theta$ were also localized to the Golgi in response to TPA. Only PKC$\delta$ was found to be associated with the nuclear membrane after transient TPA treatment. These results suggest that specific PKC isoforms are translocated to different intracellular sites and exhibit distinct biological effects.

• Archives of Plastic Surgery
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• 제34권1호
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• pp.13-17
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• 2007

Purpose: To understand the pathogenesis of the disease that presents abnormally proliferated vascular endothelial cells, a model of DMH(1,2-dimethylhydrazine)-induced abnormal proliferation of HUVECs(Human Umbilical Vein Endothelial Cells) was made. We indirectly determined that Protein Kinase C(PKC) restricts the cellular proliferation and inhibits the manifestation of growth factor by using several inhibiting substances of the transmitter through our previous studies. Thereupon, we attempted to observe direct enzymatic activities of PKC and its correlation with the abnormal proliferation of vascular endothelial cells. Methods: $10^5$ HUVECs cells were applied to 6 individual well plates in three different groups; A control group cultured without treatment, a group concentrated with $0.75{\times}10^{-8}M$ DMH only, and a group treated with DMH & $5{\times}10^{-9}M$ Calphostin C, inhibitor of PKC. In analyzing the formation of intracellular PKC enzyme, protein separation was performed, and separated protein was quantitatively measured. PKC enzyme reaction was analyzed through Protein Kinase C Assay System (Promega, USA), and the results were analyzed according to Beer's law. Results: Enzymatic activity of PKC presented the highest in all reaction time of a group concentrated only with DMH, and the lowest in the control group. The group treated with DMH and the inhibitor revealed statistically lower enzymatic activity than group only with DMH in all reaction time, although higher than the control group. Conclusion: From the enzymatic aspect, most active and immediate reaction of the PKC was observed in the group concentrated with DMH only. The group treated with DMH & PKC inhibitor showed meaningful decrease. Accordingly, PKC holds a significant role in DMH-induced abnormal proliferation of vascular endothelial cells.

• Archives of Pharmacal Research
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• 제21권2호
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• pp.120-127
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• 1998

Peroxisome proliferators induce hepatic peroxisome proliferation and hepatic tumors in rodents. These chemicals increase the expression of the peroxisomal $\beta$-oxidation pathway and the cytochrome P-450 4A family, which metabolizes lipids, including eicosanoids. Peroxisome proliferators transiently induce increased cell proliferation in vivo. However, peroxisome proliferators are weakly mitogenic and are not co-mitogenic with epidermal growth factor (EGF) in cultured hepatocytes. Earlier study found that the peroxisome proliferator ciprofibrate is cornitogenic with eicosanoids. In order to study possible mechanisms of the comitogenicity of peroxisome proliferator ciprofibrate and eicosanoids' we hypothesized that the co-mitogenicity may result from synergistic or additive increases of second messengers in mitogenic signal pathways. We therefore examined the effect of the peroxisome proliferator ciprofibrate, prostaglandin $F_2_{\alpha}$($PGF_2{\alpha}$) and the combination of ciprofibrate and $PGF_2{\alpha}$ with or without growth factors on the protein kinase C (PKC) activity, and inositol-1, 4, 5-triphosphate ($IP_{3-}$) and intracellular calcium ($[Ca^{2+}]_i$) concentrations in cultured rat hepatocytes. The combination of ciprofibrate and $PGF_2{\alpha}$ significantly increased particulate PKC activity. The combination of ciprofibrate and $PGF_2{\alpha}$ also significantly increased EGF, transforming growth factor-$\alpha$ ($TGF_2{\alpha}$) and hepatic growth factor (HGF)-induced particulate PKC activity. The combination of ciprofibrate and $PGF_2_\alpha$greatly increased $[Ca^{2+}]_i$. However, the increases of PKC activity and $[Ca^{2+}]_i$ by ciprofibrate and $PGF_2{\alpha}$ alone were much smaller. Neither ciprofibrate or $PGF_2{\alpha}$ alone nor the combination of ciprofibrate and $PGF_2{\alpha}$ significantly increased the formation of $IP_3$. The combination of ciprofibrate and $PGF_2{\alpha}$, however, blocked the inhibitory effect of $TGF-{\beta}$ on particulate PKC activity and formation of $IP_3$ induced by EGF. These results show that co-mitogenicity of the peroxisome proliferator ciprofibrate and eicosanoids may result from the increase in particulate PKC activity and intracellular calcium concentration but not from the formation of $IP_3$.

• 생명과학회지
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• 제13권5호
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• pp.551-558
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• 2003

C형 간염바이러스는 간암을 야기하는 심각한 바이러스이다. C형 간염바이러스의 core 단백질의 과발현은 섬유아세포를 암화시키는 것으로 알려져 있다. Phospholipase D (PLD)의 효소활성이 세포증식 신호전달에 의해 활성화되어 있으며, 사람의 암조직에서 과발현 및 활성이 증가되어 있는 것으로 알려져 있다. 본 연구의 목적은, core 단백질에 의해 암화된 세포에서 PLD가 어떻게 조절되는지를 이해하고자 하는 것이다. 자극이 없는 상태에서뿐만 아니라 PMA에 의해 유도되는 PLD효소활성은, 암화된 세포에서 더 증가하였으며, control 세포와 core 단백질에 의해 암화된 세포에서 PLD와 PKC 단백질의 발현은 서로 유사하였다. PKC 특이적인 억제제와 PKC의 세포막으로의 이동에 관한 실험을 통해서, PKC-d가 암화된 세포에서 PMA에 의해 유도되는 PLD활성의 증가에 중요하게 관여하고 있음을 밝혔다. 이러한 결과는, PLD가 core 단백질에 의해 유도되는 세포의 암화과정에 관여하고 있을 것으로 추정된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권4호
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• pp.1177-1182
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• 2012

Protein kinase C (PKC) has been implicated in carcinogenesis and displays variable expression profiles during cancer progression. Studies of dietary phytochemicals on cancer signalling pathway regulation have been conducted to search for potent signalling regulatory agents. The present study was designed to evaluate any suppressive effect of maslinic acid on PKC expression in human B-lymphoblastoid cells (Raji cells), and to identify the PKC isoforms expressed. Effects of maslinic acid on PKC activity were determined using a PepTag$^{(R)}$ assay for non-radioactive detection of PKC. The highest expression in Raji cells was obtained at 20 nM PMA induced for 6 hours. Suppressive effects of maslinic acid were compared with those of four PKC inhibitors (H-7, rottlerin, sphingosine, staurosporine) and two triterpenes (oleanolic acid and ursolic acid). The $IC_{50}$ values achieved for maslinic acid, staurosporine, H-7, sphingosine, rottlerin, ursolic acid and oleanolic acid were 11.52, 0.011, 0.767, 2.45, 5.46, 27.93 and $39.29\;{\mu}M$, respectively. Four PKC isoforms, PKC ${\beta}I$, ${\beta}II$, ${\delta}$, and ${\zeta}$, were identified in Raji cells via western blotting. Maslinic acid suppressed the expression of PKC ${\beta}I$, ${\delta}$, and ${\zeta}$ in a concentration-dependent manner. These preliminary results suggest promising suppressive effects of maslinic acid on PKC activity in Raji cells. Maslinic acid could be a potent cancer chemopreventive agent that may be involved in regulating many downstream signalling pathways that are activated through PKC receptors.