• International Journal of Oral Biology
• /
• v.30 no.2
• /
• pp.47-57
• /
• 2005

Leptin, the product of the obese gene, is a circulating hormone secreted primarily from adipocytes. Several results suggest that leptin is important mediators of bone metabolism. The present study was undertaken to determine the effects of leptin on anti-osteoclastogenesis using murine precursors cultured on Ca-P coated plates and on the production of osteoprotegerin (OPG) in osteoblastic cells. Additionally, this study examined the possible involvement of prostaglandin $E_2\;(PGE_2)$/protein kinase C (PKC)-mediated signals on the effect of leptin on anti-osteoclastogenesis to various culture systems of osteoclast precursors. Osteoclast generation was determined by counting tartrate-resistant acid phosphatase positive [TRAP (+)] multinucleated cells (MNCs). Osteoclastic activity was determined by measuring area of resorption pits formed by osteoclasts on Ca-P coated plate. The number of 1,25-dihydroxycholecalciferol $(1,25[OH]_2D_3)$- or $PGE_2$-induced TRAP (+) MNCs in the mouse bone marrow cell culture decreased significantly after treatment with leptin. The number of receptor activator of NF-kB ligand (RANKL)-induced TRAP (+) MNCs in M-CSF dependent bone marrow macrophage (MDBM) cell or RAW264.7 cell culture decreased significantly with leptin treatment. Indomethacin inhibited osteoclast generation induced by $1,25[OH]_2D_3$ and dexamethasone, however, no significant differences were found in the leptin treated group when compared to the corresponding indomethacin group. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, inhibited osteoclast generation induced by $1,25[OH]_2D_3$. The number of TRAP (+) MNCs decreased significantly with treatment by PMA at concentrations of 0.01 and $0.1{\mu}M$ in culture. Leptin inhibited PMA-mediated osteoclast generation. Isoquinoline-5-sulfonic 2-methyl-1-piperazide dihydrochloride (H7) had no effect on osteoclast generation induced by $1,25[OH]_2D_3$. Cell culture treatment with leptin resulted in no significant differences in osteoclast generation compared to the corresponding H7 group. Indomethacin showed no significant effect on TRAP (+) MNCs formation from the RAW264.7 cell line. PMA inhibited TRAP (+) MNCs formation induced by RANKL in the RAW264.7 cell culture. H7 had no effect on osteoclast generation from the RAW264.7 cell line. There was no difference compared with the corresponding control group after treatment with leptin. $1,25[OH]_2D_3$- or $PGE_2$-induced osteoclastic activity decreased significantly with leptin treatment at a concentration of 100 ng/ml in mouse bone marrow cell culture. Indomethacin, PMA, and H7 significantly inhibited osteoclastic activity induced by $1,25[OH]_2D_3$ in mouse bone marrow cell culture. No significant differences were found between the leptin treated group and the corresponding control group. The secretion of OPG, a substance known to inhibit osteoclast formation, was detected from the osteoblasts. Treatment by leptin resulted in significant increases in OPG secretion by osteoblastic cells. Taken these results, leptin may be an important regulatory cytokines within the bone marrow microenvironment.

• Biomedical Science Letters
• /
• v.10 no.2
• /
• pp.107-113
• /
• 2004

This study was conducted to investigate an effect of Mori Cortex in the cardiac injury following dermal scald burn in rats. Sprague-Dawley rats were induced scald bum (15％ of total body surface area). Heart was removed at 5 h postburn and examined with biochemical assay, ultrastructural observations and stereological analysis. The activity of serum aspartate aminotransferase and creatinine was increased at 5 h postburn compared with them of control. Administration of heat extracts of Mori Cortex after scald burn inhibited the production of KC (neutrophil chemoattractant cytokine) and increased the activity of protein kinase C (PKC) in heart tissue. The activity of myeloperoxidase (MPO) in heart tissue was decreased both at 5 h postburn and in case of Mori Cortex administration after scald burn. Ultrastructurally, many contraction bands and separation of intercalated disk induced by scald burn were decreased by administration of heat extracts of Mori Cortex. In stereological analysis, administration of Mori Cortex after scald burn resulted the volume densities of myofibril and mitochondria were increased compared with them of burn control. These data suggest that Mori Cortex may be a useful stuff to the range of available treatments for cardiac injury induced by skin burn.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.2
• /
• pp.453-461
• /
• 2007

Drynariae Rhizoma has been used for promotes mending of the sinews and bone, tonifies the kidney for such symptoms as weak low back and knees, and stimulates the growth of hair as a tinctute for alopecia in oriental medicine. This experiment examined the effect of an acetone extracts of Drynariae Rhizomas(GSB-1), its EtoAc fraction(GB-2) and n-buOH fraction(GSB-3), on hair growth activity of the C57BL/6L mice after topical application to skin. First, We examined on hair growth activity of extracts of Drynariae Rhizomas compare to control and 1 % minoxidil groups. Second, We investigated on the number of hair follicle and mast cells after topical application of extracts of the Drynariae Rhizomas to skin for 16 day. Third, We investigated immunoreactive density of vascular endothelial growth factor(VEGF), protein kinase C-${\alpha}$(PKC-${\alpha}$) and stem(mast) cell factor(SCF) in skin of C57BL/6N mice by immunohistochemical methods. The results were as follows : Hair growth effect of acetone extracts of Drynariae Rhizomas, its EtoAc fraction and n-BuOH fraction was observed in 98 %, 96 % and 60 % in hair removed skin area in 16 day respectively, Immunoreactive density of VEGF in skin of GSB-1 group was weakly stained compare to control group in 10 day, But GSB-2 and GSB-3 groups were mildy stained in bulge and root sheath of skin. Immunolocalization of SCF antigens was observed weakly stained density in epidermis, bulge, stem cells and dermal papilla of control gruop. but in experimental group, immunoreactivity of SCF antigens was observed mildly stained density in bulge, epidermis and root sheath of GSB-1 gruop, heavily stained density in epidermis, bulge and root sheath of GSB-2 and GSB-3 groups to the hair removal skin of C57BL/6N mice on day 10. These experiment suggest that acetone extracts of Drynariae Rhizomas and its EtoAc fraction may be used for topical treatment of alopecia areata.

• Journal of Life Science
• /
• v.15 no.3 s.70
• /
• pp.406-414
• /
• 2005

The genetic instability of cancer cells may be related to inappropriately activated DNA repair pathways. In present study, the modulated expression of DNA-dependent protein kinase (DNA-PK), a major DNA repair protein, in human cancer metastatic cells was tested. The expressions of Ku70/80, regulatory subunit of DNA-PK, and the Ku DNA-binding activity in various highly metastatic cell lines were higher than those in each parental cell line. Also, the expression of DNA-PKcs, catalytic subunit of DNA-PK, and the kinase activity of the whole DNA-PK complex in highly metastatic cells were significantly increased as compared to those of parental cells, suggesting that the enhanced DNA repair capacity of metastatic cells could be associated with aberrant use of DNA repair, which may mediate tumor progression and metastatic potential. Increased EGFR (epidermal growth factor receptor) signaling has been associated with tumor invasion and metastasis, and the linkage between EGFR-mediated signaling and DNA-PK has been suggested. This study showed that PKI166, the new EGFR tyrosine kinase inhibitor, modulated the expressions of Ku70/80 and DNA-PKcs and also revealed the chemosensitization effect of PKI166 against metastatic cells may be in part due to inhibition of Ku70/80. These results suggest that interference in EGFR signaling by EGFR inhibitor resulted in the impairment of DNA repair activity, and thus DNA-PK could be possible molecular targets for therapy against metastatic cancer cells.

• Proceedings of the Ginseng society Conference
• /
• 2002.10a
• /
• pp.66-83
• /
• 2002

Recently, we have provided evidence that ginsenosides, the active components of Panax ginseng, utilize pertussis toxin (PTX)-insensitive $G{\alpha}_{q/11}-phospholipase\;C-{\beta}3(PLC-{\beta}3)$ signal transduction pathway for the enhancement of $Ca^{2+}-activated\;Cl^{-}$ current in the Xenopus oocyte (British J. Pharmacol. 132, 641-647, 2001; JBC 276, 48797-48802, 2001). Other investigators have shown that stimulation of receptors linked to $G{\alpha}-PLC$ pathway inhibits the activity of G proteincoupled inwardly rectifying $K^+$ (GIRK) channel. In the present study, we sought to determine whether ginsenosides influenced the activity of GIRK 1 and GIRK 4 (GIRK 1/4) channels expressed in the Xenopus oocyte, and if so, the underlying signal transduction mechanism. In oocyte injected with GIRK 1/4 channel cRNAs, bath-applied ginsenosides inhibited high potassium (HK) solution-elicited GIRK current $(EC_{50}:4.9{\pm}4.3\;{\mu}g/ml).$ Pretreatment of the oocyte with PTX reduced the HK solution-elicited GIRK current by $49\%,$ but it did not alter the inhibitory ginsenoside effect on GIRK current. Prior intraoocyte injection of cRNA(s) coding $G{\alpha}_q,\;G{\alpha}_{11}\;or\;G{\alpha}_q/G{\alpha}_{11},\;but\;not\;G{\alpha}_{i2}\;or\;G{\alpha}_{oA}$ attenuated the inhibitory ginsenoside effect. Injection of cRNAs coding $G{\beta}_{1{\gamma}2}$ also attenuated the ginsenoside effect. Similarly, injection of the cRNAs coding regulators of G protein signaling 1, 2 and 4 (RGS1, RGS2 and RGS4), which interact with $G{\alpha}_i\;and/or\;G{\alpha}_{q/11}$ and stimulates the hydrolysis of GTP to GDP in active GTP-bound $G{\alpha}$ subunit, resulted in a significant reduction of ginsenoside effect on GIRK current. Preincubation of GIRK channel-expressing oocyte in PLC inhibitor (U73122) or protein kinase C (PKC) inhibitor (staurosporine or chelerythrine) blocked the inhibitory ginsenoside effect on GIRK current. On the other hand, intraoocyte injection of BAPTA, a free $Ca^{2+}$ chelator, had no significant effect on the ginsenoside action. Taken together, these results suggest that ginsenosides inhibit the activity of GIRK 1/4 channel expressed in the Xenopus oocyte through a PTX-insensitive and $G{\alpha}_{q/11}$-,PLC-and PKC-mediated signal transduction pathway.

• Biomedical Science Letters
• /
• v.22 no.2
• /
• pp.60-64
• /
• 2016

In the pathogenesis of inflammatory diseases such as allergies, S100A8 acts as an important molecule and T lymphocytes are essential cytokine-releasing cells. In this study, we investigated the effect of S100A8 on release of cytokines, specifically MCP-1, IL-6, and IL-8 in T cells, and its associated signaling mechanism. S100A8 increased secretion of MCP-1, IL-6, and IL-8 in a time- and dose-dependent manner. Elevated secretion of MCP-1, IL-6, and IL-8 due to S100A8 was inhibited by the TLR4 inhibitor TLR4i, the PI3K inhibitor LY294002, the $PKC{\delta}$ inhibitor rottlerin, the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, the JNK inhibitor SP600125, and the NF-${\kappa}B$ inhibitor BAY-11-7085. S100A8 induced phosphorylation of ERK, p38 MAPK, and JNK in a time-dependent manner, and activation was suppressed by TLR4i, LY294002, and rottlerin. S100A8 induced NF-${\kappa}B$ activation by $I{\kappa}-B{\alpha}$ degradation, and NF-${\kappa}B$ activity was suppressed by PD98059, SB202190, and SP600125. These results indicate that S100A8 induces cytokine release via TLR4. Study of PI3K, $PKC{\delta}$, MAPKs, and NF-${\kappa}B$ will contribute to elucidation of the S100A8-invovled mechanism.

• Molecules and Cells
• /
• v.27 no.1
• /
• pp.113-118
• /
• 2009

In this study, we have shown the transcriptional regulation of the human GD3 synthase (hST8Sia I) induced by valproic acid (VPA) in human neuroblastoma SK-N-BE(2)-C cells. To elucidate the mechanism underlying the regulation of hST8Sia I gene expression in VPA-stimulated SK-N-BE(2)-C cells, we characterized the promoter region of the hST8Sia I gene. Functional analysis of the 5'-flanking region of the hST8Sia I gene by the transient expression method showed that the -1146 to -646 region, which contains putative binding sites for transcription factors c-Ets-1, CREB, AP-1 and NF-${\kappa}B$, functions as the VPA-inducible promoter of hST8Sia I in SK-N-BE(2)-C cells. Site-directed mutagenesis and electrophoretic mobility shift assay indicated that the NF-${\kappa}B$ binding site at -731 to -722 was crucial for the VPA-induced expression of hST8Sia I in SK-N-BE(2)-C cells. In addition, the transcriptional activity of hST8Sia I induced by VPA in SK-N-BE(2)-C cells was strongly inhibited by SP600125, which is a c-Jun N-terminal kinase (JNK) inhibitor, and $G{\ddot{O}}6976$, which is a protein kinase C (PKC) inhibitor, as determined by RT-PCR (reverse transcription-polymerase chain reaction) and luciferase assays. These results suggest that VPA markedly modulated transcriptional regulation of hST8Sia I gene expression through PKC/JNK signal pathways in SK-N-BE(2)-C cells.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.4
• /
• pp.592-597
• /
• 2002

The Rkp1/CPC2, a receptor for activated protein kinase C of Schizosaccharomyces pombe, contains seven WD motifs found in the G-protein $\beta$-subunit. A 110-kDa protein was identified to interact with Rkp1/CPC2 by immunoprecipitation and following in vitro binding assay. To examine its kinase activity and binding ability to Rkp1, the $pck1^+$, a PKC homolog of S. pombe, was cloned. Pckl phosphorylated myelin basic protein (MBP) and histone Hl in a phospholipid-dependent and $Ca^{2+}$-independent manner. It was demonstrated that the N-terminal region of Pck1 was responsible for the binding to Rkp1 , thus suggesting that Rkp1 interacted with Pckl to regulate Pckl-mediated signaling in S. pombe.

• The Journal of Internal Korean Medicine
• /
• v.34 no.1
• /
• pp.31-45
• /
• 2013

Objectives : Gokgisaeng (Korean mistletoe) is used for the treatment of inflammatory and cancer diseases in traditional Korean medicine and its major component lectins have been reported to induce nitric oxide (NO) in RAW 264.7 macrophages, and also induce apoptosis of various types of cancer cells, although its modulatory effects on cancer cell migration and macrophage activation is poorly understood. The aim of this study is to clarify molecular mechanisms of action responsible for the anti-inflammatory and antitumor migration potentials of Korean mistletoe extract (KME). Methods : We investigated the anti-inflammatory activity of KME on NO production and inducible nitric oxide synthase (iNOS) expression by lipopolysaccharide (LPS) in both RAW 264.7 macrophages and rat C6 glioma cells, and also evaluated inhibitory efficacy on glioma cell growth and migration. For assessment, XTT assay, nitrite assay, RT-PCR, scratch-wound and Boyden chamber assay, and western blot analysis were performed. Results : Previously reported, unlike the efficacy of Gokgisaeng lectin, KME inhibited NO production and iNOS expression, and suppressed pro-inflammatory mediators including IL-$1{\beta}$, IL-6, COX-2, iNOS in LPS-stimulated RAW 264.7 cells. Furthermore, KME suppressed tumor cell growth and migration, and it also inhibited LPS-induced NO release and iNOS activation by down-regulating expression of protein kinase C (PKC) and phosphorylation of ERK in C6 glioma cells. Conclusions : Our research findings provide evidence that KME can play a significant role in blocking pro-inflammatory reaction and malignant progression of tumors through the suppression of NO/iNOS by down-regulating of inflammatory signaling pathways, PKC/ERK.

• Herbal Formula Science
• /
• v.28 no.1
• /
• pp.71-80
• /
• 2020

Obejectives : The purpose of this study was to investigate the effects of Yijin-tang on pacemaker potentials of small intestinal interstitial Cells of Cajal (ICC). Methods : To dissociate the ICC, we used enzymatic digestions from the small intestine in mice. The electrophysiological whole-cell patch-clamp configuration was used to record pacemaker potentials in the cultured ICC and the in vivo effects of Yijin-tang on GI motility were investigated by calculating percent intestinal transit rates (ITR). Results : 1. The ICC generated pacemaker potentials in the murine small intestine. Yijin-tang produced membrane depolarization with concentration-dependent manners in the current clamp mode. 2. Pretreatment with a Ca²⁺ free solution and thapsigargin, a Ca²⁺-ATPase inhibitor in the endoplasmic reticulum, stopped the pacemaker potentials. In the case of Ca²⁺-free solutions and thapsigargin, Yijin-tang did not induce membrane potential depolarizations. 3. U73122, a phospholipase C (PLC) inhibitors, blocked the Yijin-tang-induced membrane potential depolarizations. However, U73343, an inactive PLC inhibitors, did not block. 4. In the presence of protein kinase C (PKC) inhibitors, staurosporine or Rottlerin, Yijin-tang depolarized the pacemaker potentials. However, in the presence of Go6976, Yijin-tang did not depolarize the pacemaker potentials. 5. In mice, intestinal transit rate (ITR) values were significantly and dose-dependently increased by the intragastric administration of Yijin-tang. Conclusions : These results suggest that Yijin-tang can modulate the pacemaker activity of ICC through an internal/external Ca²⁺ and PLC/PKC-dependent pathway in ICC. In addition, Yijin-tang is a good candidate for the development of a prokinetic agent.