• Title/Summary/Keyword: PKC${\beta}$

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The Stimulatory Effect of Essential Fatty Acids on Glucose Uptake Involves Both Akt and AMPK Activation in C2C12 Skeletal Muscle Cells

  • Park, So Yeon;Kim, Min Hye;Ahn, Joung Hoon;Lee, Su Jin;Lee, Jong Ho;Eum, Won Sik;Choi, Soo Young;Kwon, Hyeok Yil
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.3
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    • pp.255-261
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    • 2014
  • Essential fatty acid (EFA) is known to be required for the body to function normally and healthily. However, the effect of EFA on glucose uptake in skeletal muscle has not yet been fully investigated. In this study, we examined the effect of two EFAs, linoleic acid (LA) and ${\alpha}$-linolenic acid (ALA), on glucose uptake of C2C12 skeletal muscle cells and investigated the mechanism underlying the stimulatory effect of polyunsaturated EFAs in comparison with monounsaturated oleic acid (OA). In palmitic acid (PA)-induced insulin resistant cells, the co-treatment of EFAs and OA with PA almost restored the PA-induced decrease in the basal and insulin-stimulated 2-NBDG (fluorescent D-glucose analogue) uptake, respectively. Two EFAs and OA significantly protected PA-induced suppression of insulin signaling, respectively, which was confirmed by the increased levels of Akt phosphorylation and serine/threonine kinases ($PKC{\theta}$ and JNK) dephosphorylation in the western blot analysis. In PA-untreated, control cells, the treatment of $500{\mu}M$ EFA significantly stimulated 2-NBDG uptake, whereas OA did not. Phosphorylation of AMP-activated protein kinase (AMPK) and one of its downstream molecules, acetyl-CoA carboxylase (ACC) was markedly induced by EFA, but not OA. In addition, EFA-stimulated 2-NBDG uptake was significantly inhibited by the pre-treatment of a specific AMPK inhibitor, adenine 9-${\beta}$-D-arabinofuranoside (araA). These data suggest that the restoration of suppressed insulin signaling at PA-induced insulin resistant condition and AMPK activation are involved at least in the stimulatory effect of EFA on glucose uptake in C2C12 skeletal muscle cells.

Anti-nociceptive and Anti-inflammatory Effects of Gami-cheongyulsaseub-tang in Arthritic Model (관절염 모델에서 가미청열사습탕(加味淸熱瀉濕湯)의 진통 및 소염 효과에 관한 연구)

  • Kim, Il-Hyun;Lee, Ha-Il;Lee, Se-Won;Kwon, Young-Mi;Song, Yung-Sun
    • Journal of Korean Medicine Rehabilitation
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    • v.25 no.1
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    • pp.27-44
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    • 2015
  • Objectives This study was carried out to find the effects of Gami-cheongyulsaseub-tang (hereinafter referred to GCST) on the inhibition of zymosan-induced pain in rats and collagen II-induced arthritis (CIA) in DBA/1J mouse. Methods As an acute inflammatory pain model, peripheral inflammation was induced by intraplantar injection of zymosan into the right hind paw in rats and then the hyperalgesia and pain regulating factors in spinal cord were analyzed. As a chronic inflammation model, the mixture of collagen II and complete Freund's adjuvant was treated into mice to establish rheumatoid arthritis and then body weight, thickness of hind paw, pathological change of spleen, immunological rheumatoid factor (IgG1, IgG2a, IgG2b, IgM and anti-collagen II), pro-inflammatory cytokines, and bone injury were analyzed. Results In the acute inflammatory pain model, GCST significantly inhibited the thermal and mechanical hyperalgesia and the pain regulating factors, including Fos, CD11b, PKA and PKC, in the spinal cord with a dose-dependent manner. In the chronic rheumatoid arthritis model, GCST administration decreased arthritic index and paw edema as compared with CIA control group. In particular, GCST reduced significantly the serum levels of total IgG2a, IgG2b, IgM, and specific anti-collagen II, but not total IgG1. GCST also resulted in the attenuation of bone injury and spleen enlargement/adhesion in CIA mice. Moreover, the secretion of pro-inflammatory cytokines TNF-${\alpha}$ and IL-$1{\beta}$ in CIA mice was significantly reduced by GCST in a dose-dependent manner. Conclusions Comparison of the results in this study showed that GCST had anti-nociceptive and immunomodulatory effects. These data imply that GCST can be used as an effective drug for not only rheumatoid arthritic pain but also other auto-immune diseases.

Experimental Studies on the Hair Growth Activity of Extracts of Pinelliae Rhizoma in Spontaneous Alopecia Model and Normal C57BL/6N Mice (반하추출물(半夏抽出物)이 자발적 원형탈모 생쥐와 정상 생쥐의 발모효과에 대한 실험적 연구)

  • Jeong, Il-Kook;Jo, Han-Young;Kim, Tae-Heon;Kim, Nam-Seok;Jeong, Han-Sol;Lee, Chang-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.1
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    • pp.84-92
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    • 2009
  • This experiment was investigated the effects of fresh and ginger processed Pinelliae Rhizoma extracts on hair growth activity, and its fractions(chloroform, ethyl acetate and water fractions) obtained from fresh Pinelliae Rhizoma on hair growth activity of the normal and spontaneous alopecia areata model of C57BL/6N mice for 16 days. The results were as follows: In fresh Pinelliae Rhizoma extracts treated group, hair growth effect was observed in whole skin area(100%) all the normal mice in whose hair had been clipped on 16th days. In ginger processed Pinelliae Rhizoma extracts treated group, hair growth effect was observed in whole skin area in 25% of normal mice in whose hair had been clipped on 16th days. But in control group, hair growth effect was observed in a part of whole skin area in 25% of normal mice. In fresh Pinelliae Rhizoma extracts treated group, hair follicles of middle stage of anagen phase was observed and it were grown down to subcutaneous tissue of skin in all the mice on 10th day. But in ginger processed Pinelliae Rhizoma extracts treated group and control group, Most of hair follicles of telogen phase was observed in skin. The treatment of extracts of fresh Pinelliae Rhizoma increased the expression of TGF-$\beta$(146%), IGF(107%), and prolactin(115%) in the skin of normal C57BL/6N mice compared to control group(100%). But expression of placenta lactogen(93%) was decreased in the skin of normal C57BL/6N mice compared to control group(100%). In spontaneous alopecia model, The hair growth activity of fresh Pinelliae Rhizoma extracts treated group(100%) was observed to be strong compared with the control group(20%) on 15th day. Hair growth activity on chloroform fractions of fresh Pinelliae Rhizoma extracts was observed in whole skin area in 75% of normal mice on the 9th day. In water and ethyl acetate fractions, hair growth activity was observed in a part of whole skin in 75% and 25% of normal mice, respectively. but hair growth activity of control group was not observed. After application of fractions of fresh Pinelliae Rhizoma extracts for 10 days, hair follicles of chloroform fraction treated group was observed middle stage of anagen phase and hair follicle were grown down to subcutaneous tissue of skin in all the mice. But hair follicles of initial stage of anagen phase were observed in water and ethyl acetate fractions. Most of hair follicles of telogen phase was observed in skin of control group. These experiments suggest that extracts of fresh Pinelliae Rhizoma may stimulate the topical hair growth activity and its chloroform fractions can be useful for treatment of alopecia areata.

Effect of Protein Kinase C Inhibitor (PKCI) on Radiation Sensitivity and c-fos Transcription Activity (Protein Kinase C Inhibitor (PKCI)에 의한 방사선 민감도 변화와 c-fos Proto-oncogene의 전사 조절)

  • Choi Eun Kyung;Chang Hyesook;Rhee Yun-Hee;Park Kun-Koo
    • Radiation Oncology Journal
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    • v.17 no.4
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    • pp.299-306
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    • 1999
  • Purpose : The human genetic disorder ataxia-telangiectasia (AT) is a multisystem disease characterized by extreme radiosensitivity. The recent identification of the gene mutated in AT, ATM, and the demonstration that it encodes a homologous domain of phosphatidylinositol 3-kinase (PI3-K), the catalytic subunit of an enzyme involved in transmitting signals from the cell surface to the nucleus, provide support for a role of this gene in signal transduction. Although ionizing radiation was known to induce c-fos transcription, nothing is known about how ATM or PKCI mediated signal transduction pathway modulates the c-fos gene transcription and gene expression. Here we have studied the effect of PKCI on radiation sensitivity and c-fos transcription in normal and AT cells. Materials and Methods: Normal (LM217) and AT (AT5BIVA) cells were transfected with PKCI expression plasmid and the overexpression and integration of PKCI was evaluated by northern blotting and polymerase chain reaction, respectively. 5 Gy of radiation was exposed to LM and AT cells transfected with PKCI expression plasmid and cells were harvested 48 hours after radiation and investigated apoptosis with TUNEL method. The c-fos transcription activity was studied by performing CAT assay of reporter gene after transfection of c-fos CAT plasmid into AT and LM cells. Results: Our results demonstrate for the first time a role of PKCI on the radiation sensitivity and c-fos expression in LM and AT cells. PKCI increased radiation induced apoptosis in LM cells but reduced apoptosis in AT cells. The basal c-fos transcription activity is 70 times lower in AT cells than that in LM cells. The c-fos transcription activity was repressed by overexpression of PKCI in LM cells but not in AT cells. After induction of c-fos by Ras protein, overexpression of PKCI repressed c-fos transcription in LM cells but not in AT cells Conclusion: Overexpression of PKCI increased radiation sensitivity and repressed c-fos transcription in LM cells but not in AT cells. The results may be a. reason of increased radiation sensitivity of AT cells. PKCI may be involved in an ionizing radiation induced signal transduction pathway responsible for radiation sensitivity and c-fos transcription. The data also provided evidence for novel transcriptional difference between LM and AT cells.

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Mechanisms of Insulinotropic Effect of YHB-2017 [Genistein] Isolated from fermentation Broths of Streptomyces sp. (방선균에서 유래한 YHB-2017 [Genistein]의 인슐린 분비 촉진 작용 기전)

  • Kwag, Won-Jae;Park, You-Hoi;Park, Jun-Chul;Lee, Byung-Kyu;Kang, Yup;Choe, Tae-Boo
    • KSBB Journal
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    • v.21 no.6 s.101
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    • pp.466-473
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    • 2006
  • Impaired insulin secretion from pancreatic beta-cells in response to glucose is an important feature in the pathology of non-insulin-dependent diabetes mellitus (NIDDM). In the course of screening for useful insulin secretagogues, we have isolated and identified YHB-2017 (Genistein) as a insulin secretion potentiator from fermentation broths of our in-house microbial library. The insulinotropic activity of YHB-2017 in isolated rat pancreatic islets was exerted only at high concentration of glucose (8.3-16 mM) but not at low concentration of glucose (3.3-5.5 mM). Also, in perifusion study with isolated rat pancreatic islets, YHB-2017 stimulated insulin secretion in a time-dependent manner when YHB-2017 was added to KRB buffer containing 16 mM glucose. In the presence of $200\;{\mu}M$ diazoxide and 35 mM KCI, which stimulates maximum $Ca^{2+}$ influx independently of KATP channel, YHB-2017 enhanced KATP channel-independent insulin secretion at high concentration glucose (16 mM). To elucidate the mechanisms of the glucose-dependent potentiation effect of YHB-2017, pharmacologic inhibitors for protein kinase A, protein kinase C and calcium/calmodulin kinase II were pre-treated and then the potentiation effect of YHB-2017 on insulin secretion was investigated. Pre-treatment of H89 as a PKA inhibitor had a significant inhibitory effect on YHB-2017-induced potentiation effect. Furthermore, western immunoblotting analyses revealed that YHB-2017 increased phosphorylation of PKA substrates and cAMP response element-binding protein (CREB) under high concentration of glucose. These results demonstrated that the insulinotropic effect of YHB-2017 is mediated through PKA signal pathway and activated amplifying $K_{ATP}$ channel-independent insulin secretion pathway.