• Environmental Mutagens and Carcinogens
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• v.25 no.2
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• pp.51-59
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• 2005

Overexpression of HSP25 delayed cell growth, increased the level of $p21^{waf}$, reduced the levels of cyclin D1, cylcin A and cdc2, and induced radioresistance in L929 cells. We demonstrated that extracellular regulated kinase (ERK) and MAP kinase/ERK kinase (MEK) expressions as well as their activation (phospho-forms) were inhibited by hsp25 overexpression. To confirm the relationship between ERK1/2 and hsp25-mediated radioresistance, ERK1 or ERK2 cDNA was transiently transfected into the hsp25 overexpressed cells and their radioresistance was examined. HSP25-mediated radioresistance was abolished by overexpression of ERK2, but not by overexpression of ERK1. Alteration of cell cycle distribution and cell cycle related protein expressions (cyclin D, cyclin A and cdc2) by hsp25 overexpression were also recovered by ERK2 cDNA transfection. Increase in Bc1-2 protein by hsp25 gene transfection was also reduced by subsequent ERK2 cDNA-transfection. In addition, HSP25 overexpression reduced reactive oxygen species (ROS) and increased expression of manganese superoxide dismutase (MnSOD) gene. Increased activation of NF-kB (IkB degradation) was also found in hsp25-overexpressed cells. Moreover, transfection of hsp25 antisense gene abrogated all the HSP25-mediated phenomena. To further elucidate the exact relationship between MnSOD induction and NF-kB activation, dominant negative $I-kB\alpha(I-kB\alpha-DN)$ construction was transfected to HSP25 overexpressed cells. $I-kB\alpha-DN$ inhibited HSP25 mediated MnSOD gene expression. In addition, HSP25 mediated radioresistance was blocked by $I-kB\alpha-DN$ transfection. Blockage of MnSOD with antisense oligonucleotides in HSP25 overexpressed cells, prevented apoptosis and returned the ERK1/2 activation to the control level. From the above results, we suggest for the first time that reduced oxidative damage by HSP25 was due to MnSOD-mediated down regulation of ERK1/2.

• Biomolecules & Therapeutics
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• v.18 no.4
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• pp.442-447
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• 2010

This study was conducted to determine whether treatment with the anti-inflammatory eupatilin influences intestinal smooth muscle contraction stimulated by carbachol and, if so, to investigate the related mechanism. Denuded ileal or colonic muscles from Sprague-Dawley rats were used for the study and measurements of isometric contractions were obtained using a computerized data acquisition system; this data was also combined with results from molecular experiments. Eupatilin from Artemisia asiatica Nakai significantly decreased carbachol-induced contractions in both ileal and colonic muscles. Interestingly, eupatilin decreased carbachol-induced phosphorylation of ERK1/2 more significantly than that of MYPT1 at Thr855 in ileal and colonic muscles. However, eupatilin significantly decreased phosphorylation of MYPT1 at Thr855, but only in ileal muscle. Therefore, thin filament regulation, including MEK inactivation and related phospho-ERK1/2 decrease, is mainly involved in the eupatilin-induced decrease of intestinal contraction induced by carbachol. In conclusion, this study provides the evidence and a possible related mechanism concerning the inhibitory effect of the flavonoid as an antispasmodic on the agonist-induced contractions in rat ileum and colonic muscles.

• The Journal of Korean Medicine
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• v.27 no.1 s.65
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• pp.220-228
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• 2006

Objectives : Interleukin-1 (IL-1)${\beta}$ in articular chondrocytes regulates differentiation, apoptosis, and inflammatory responses. It is still controversial, So, we investigated IL- $1{\beta}$ induces chondrocytes dedifferentiation and death. Also, we studied the role of the mitogen-activated protein kinase (MAPK) subtypes on IL-$1{\beta}$-induced dedifferentiation and apoptosis. Methods : To evaluation of dedifferentiation by chemokines of chondrocytes, we assessed such as proteoglycan, collagen, MMP-3 and MMP-13 by RT-PCR analysis. Also, to assess of apoptosis effect by chemokines, we measured annexin V/propidium iodode (PI) and sub G1 cells in chondrocytes by flowcytometric analysis Results : IL-$1{\beta}$ treatment did not affect activation of ERK-1/2, but stimulation of p38 kinase. Inhibition of phospho ERK-1/2 with PD98059 enhanced IL-1b-induced dedifferentiation, and apoptosis up to 13.5%, whereas inhibition of phospho p38 kinase with SB203580 inhibited dedifferentiation, and apoptosis. Conclusions : Our results indicate that SB203580, p38 kinase inhibitor, inhibits IL-$1{\beta}$-induced dedifferentiation, and apoptosis by the inhibition of type II collagen expression and proteoglycan synthesis of rabbit articular chondrocytes.

• The Journal of Korean Medicine
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• v.29 no.5
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• pp.14-28
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• 2008

Objective : This study was carried out to understand effects of ginseng(hearinafter ; GS, Panax Ginseng) extract on regeneration responses on injured sciatic nerves in rats. Methods :Using white mouse, we damaged sciatic nerve & central nerve, and then applied GS to the lesion. Then we observed regeneration of axon and non-neuron. Results : 1. NF-200 protein immunostaining for the visualization of axons showed more distal elongation of sciatic nerve axons in GS-treated group than saline-treated control 3 and 7 days after crush injury. 2. GAP-43 protein was increased in the injured sciatic nerve and further increased by GS treatment. Enhanced GAP-43 protein signals were also observed in DRG prepared from the rats given nerve injury and GS treatment. 3. GS treatment in vivo induced enhanced neurite outgrowth in preconditioned DRG sensory neurons. In vitro treatment of GS on sensory neurons from intact DRG also caused increased neurite outgrowth. 4. Phospho-Erk1/2 protein levels were higher in the injured nerve treated with GS than saline. Phospho-Erk1/2 protein signals were mostly found in the axons in the injured nerve. 5. NGF and Cdc2 protein levels showed slight increases in the injured nerves of GS-treated group compared to saline-treated group. 6. The number of Schwann cell population was significantly increased by GS treatment in the injured sciatic nerve. GS treatment with cultured Schwann cells increased proliferation and Cdc2 protein signals. 7. GS pretreatment into the injured spinal cord generated increased astrocyte proliferation and oligodendrocytes in culture. In vitro treatment of GS resulted in more differentiated pericytoplasmic processes compared with saline treatment. 8. More arborization around the injury cavity and the occurrence at the caudal region of CST axons were observed in GS-treated group than in saline-treated group. Conclusion :GS extract may have the growth-promoting activity on regenerating axons in both peripheral and central nervous systems.

• Journal of Life Science
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• v.13 no.6
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• pp.849-855
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• 2003

Nitric oxide (NO) plays an important role as a signaling molecule in the proliferation of placenta trophoblasts. In this study, we investigated the effect of NO on the activation of phospholipase C (PLC) in BeWo cells, choriocar-cinoma cell line. Sodium nitroprusside (SNP), an agent to produce NO spontaneously in cells, alone increased $［^3H］$ thymidine incorporation of BeWo cells, indicating NO stimulates proliferation of the cells. NO-induced proliferation of BeWo cells was blocked by U73122, an inhibitor of PLC, suggesting that NO-induced PLC activation is involved in the cell proliferation. NO also stimulated extracellular signal-regulated kinase (ERK) in BeWo cells, indicated by increased phosphorylation of ERK1/2 in Western blotting using anti-phospho-ERK1/2 antibody. NO-induced phos-phorylation of ERK1/2 was not abrogated by U73122. $PLC\gamma_1$l but not$PLC\gamma_2$ was tyrosine phosphorylated by SNP in immunoprecipitation assay using anti-$PLC\gamma_1$/$PLC\gamma_2$ antibodies, and SNP-induced phosphorylation of $PLC\gamma_1$ was abrogated by pre-treatment of cells with genistein and PD98059, indicating that NO induced-phosphorylation of $PLC\gamma_1$ is mediated by ERK. These results suggest that NO stimulates the proliferation of BeWo cells through ERK and $PLC\gamma_1$.

• IMMUNE NETWORK
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• v.5 no.4
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• pp.237-246
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• 2005

Background: Little information is available on the identification and characterization of the upstream regulators of the signal transduction cascades for Mycobacterium tuberculosis (M. tbc)-induced ERK 1/2 activation and chemokine expression. We investigated the signaling mechanisms involved in expression of CCL3 /MIP-1 and CCL4/MIP-1 in human primary monocytes infected with M. tbc. Methods: MAP kinase phosphorylation was determined using western blot analysis with specific primary antibodies (ERK 1/2, and phospho-ERK1/2), and the upstream signaling pathways were further investigated using specific inhibitors. Results: An avirulent strain, M. tbc H37Ra, induced greater and more sustained ERK 1/2 phosphorylation, and higher CCL3 and CCL4 production, than did M. tbc H37Rv. Specific inhibitors for mitogen-activated protein kinase (MAPK) kinase (MEK; U0126 and PD98059) significantly inhibited the expression of CCL3 and CCL4 in human monocytes. Mycobactetia-mediated expression of CCL3 and CCL4 was not inhibited by the Ras inhibitor manumycin A or the Raf-1 inhibitor GW 5074. On the other hand, phospholipase C (PLC) inhibitor (U73122) and protein kinase C (PKC)specific inhibitors ($G\ddot{o}6976$ and Ro31-8220) significantly reduced M. tbc-induced activation of ERK 1/2 and chemokine synthesis. Conclusion: These results are the first to demonstrate that the PLC-PKC-MEK-ERK, not the Ras-Raf-MEK-ERK, pathway is the major signaling pathway inducing M. tbc-mediated CCL3 and CCL4 expression in human primary monocytes.

• The Journal of Korean Medicine
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• v.34 no.3
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• pp.126-142
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• 2013

Objectives: Previous reports have shown that Bogijetong-Tang (BJT) is effective in peripheral neuropathy induced by taxol and crush injury. In this study, we researched the effects of BJT on diabetic neuropathy induced by STZ in the mouse. Methods: We performed both in vitro and in vivo experiments to verify the effects of BJT on diabetic neuropathy induced by STZ in mice. Changes in axonal recovery were observed with immunofluorescence staining using NF-200, Hoechst33258, $S100{\beta}$, caspase 3 and anti-cdc2. Proliferation and degeneration of Schwann cells were investigated by immunofluorescence staining and western blot analyses. Results: BJT showed considerable effects on neurite outgrowth and axonal regeneration in diabetic neuropathy. BJT contributed to the creation of NF-200, GAP-43, Cdc2, phospho-vimentin, ${\beta}1$, active ${\beta}1$, ${\beta}3$ integrin, phospho-Erk1/2 protein. Conclusions: Through this study, we found that BJT is effective for enhanced axonal regeneration via dynamic regulation of regeneration-associated proteins. Therefore, BJT had a pharmaceutical property enhancing recovery of peripheral nerves induced by diabetic neuropathy and could be a candidate for drug development after more research.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1299-1303
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• 2008

Since exercise training induces mechanical stress to the heart, we examined the activation pattern of mitogen-activated protein kinase(MAPK)s signaling pathway by immunohistochemistry. The immunoreactions of MAPKs signaling with c-fos and Schiff's reaction were increased in the cardiac muscle of exercised rat compared to normal one except immunoreaction for MEK1/2 and ERK1/2 and p38. However, the immunoreaction of phospho-JNK and phospho-p38 with early gene c-fos were arrested markedly in water extract of Alliium sativum (WEAS) treated rat compared to exercised one. Since MAPKs signaling does play a protective role in response to pathological stimulus in the heart, results in the present study suggest that WEAS may act as a alleviating agent for exercise-induced stress to. heart through regulating MAPKs signaling activation.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.101-108
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• 2005

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) is a well-known inducer of apoptotic cell death in many tumor cells. 1RAIL is expressed in human placenta, and cytotrophoblast cells express 1RAIL receptors. However, the role of TRAIL in human placentas and cytotrophoblast cells is not. well understood. In this study a trophoblast cell line, JEG-3, was used as a model system to examine the effect of TRAIL. on key intracellular signaling pathways involved in the control of trophoblastic cell apoptosis and survival JEG-3 cells expressed receptors for 1RAIL, death receptor (DR) 4, DR5, decoy receptor (OcR) 1 and DeR2. Recombinant human TRAIL (rhTRAIL) did not have a cytotoxic effect determined by MIT assay and did not induce apoptotic cell death determined by poly-(ADP-ribose) polymerase cleavage assay. rhTRAIL induced a rapid and transient nuclear translocation of nuclear $factor-{\kappa}B(NF-{\kappa}B)$ determined by immunoblotting using nuclear protein extracts. rhTRAIL rapidly activated extracellular signal-regulated protein kinase (ERK) 1/2 as determined by immnoblotting for phospho-ERK1/2. However, c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (p38MAPK) and Akt (protein kinase B) were not activated by rhTRAIL. The ability of 1RAIL to induce $NF-{\kappa}B$ and ERK1/2 suggests that interaction between TRAIL and its receptors may play an important role in trophoblast cell function during pregnancy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.4983-4988
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• 2013

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.