• Natural Product Sciences
• /
• v.14 no.2
• /
• pp.113-117
• /
• 2008

Saururus chinensis is a commonly used folk herb for the treatment of edema and liver diseases in Korea. To study the biological activity of Saururus chinensis in bone metabolism, we evaluated the effect of its extracts on osteoclast differentiation in vitro using primary mouse bone marrow-derived macrophages. Methanol extract (ME) from dried roots of Saururus chinensis was partitioned into methylene chloride (MF), ethyl acetate (EF), n-butanol (BF) and water fractions (WF). Tartrate-resistance acid phosphatase (TRAP) activity assay and western blot analysis were performed to determine the effect on osteoclast differentiation and mitogen-activated protein (MAP) kinases activation. ME, MF and EF dramatically inhibited receptor activator of ${NF-kB}$ ligand (RANKL)-induced formation of multinucleated osteoclasts and activation of MAP kinases. This study firstly demonstrated that ME, MF and EF of Saururus chinensis have the potential to inhibit the osteoclast differentiation, which results from the inhibition of MAP kinases activations in part.

• IMMUNE NETWORK
• /
• v.5 no.1
• /
• pp.30-35
• /
• 2005

Background: p38 and extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling are thought to have critical role in lipopolysaccharide (LPS)-induced immune response but the molecular mechanism underlying the induction of these signaling are not clear. Methods: Specific inhibitors for p38, SB203580, and for ERK, PD98059 were used. Cells were stimulated by LPS with or without specific MAPK inhibitors. Results: LPS activated inducible nitric oxide synthase (iNOS), subsequent NO productions, and pro-inflammatory cytokine gene expressions (TNF-${\alpha}$, IL-$1{\beta}$, IL-6, and IL-12). Treatment of both SB203580 and PD98059 decreased LPS-induced NO productions. Concomitant decreases in the expression of iNOS mRNA and protein were detected. SB203580 and PD98059 decreased LPS-induced gene expression of IL-$1{\beta}$ and IL-6. SB203580 increased LPS-induced expression of TNF-${\alpha}$ and IL-12, and reactive oxygen species production, but PD98059 had no effect. Conclusion: These results indicate that both p38 and ERK pathways are involved in LPS-stimulated NO synthesis, and expression of IL-$1{\beta}$ and IL-6. p38 signaling pathways are involved in LPS-induced TNF-${\alpha}$ and IL-12, and reactive oxygen species plays an important role in these signaling in macrophage.

• Preventive Nutrition and Food Science
• /
• v.15 no.1
• /
• pp.19-23
• /
• 2010

This study examined the effects of Acrylamide (ACR) and L-ascorbic acid (AsA) on the proliferation of splenocytes and the mitogen-stimulated lymphocyte proliferation in young (8 weeks) and aged (82 weeks) C57BL/6male mice in vitro. AsA increased splenocyte proliferation in both groups; however, this effect was higher in old mice, while the proliferation of lymphocyte was decreased except for treatment at $1\;{\mu}g/mL$ low concentration in both mice. In addition, ACR treatment resulted in decreased LPS-induced B lymphocyte proliferation and ConA-induced T lymphocyte proliferation in both groups. However, AsA increased LPS/ConA-induced lymphocyte proliferation in young groups and had no effects in old mice except at $0.5\;{\mu}g/mL$ Thus, the present data indicate that there is no difference effect of ACR and AsA on lymphocyte proliferation, whereas the effect of AsA on mitogen-induced cell proliferation was reduced in old mice. Overall, our results suggest that various immunomodulators have differing effects of lymphocytic proliferation on young versus aged mice.

• The Korean Journal of Physiology and Pharmacology
• /
• v.6 no.3
• /
• pp.155-160
• /
• 2002

It is not known whether gender differences play a role in susceptibility to ischemic acute renal failure. Thus, we examined if there were any differences in susceptibility between male and female mice to kidney ischemic injury, and if so, whether it is due to differences in mitogen activated protein kinases (MAPKs) or inflammatory responses to ischemia. Female mice were protected against kidney ischemia when compared with males. Thirty minutes of bilateral ischemia resulted in marked functional and morphological damages in males, but not in females. The ischemia-induced phosphorylation of c-jun N-terminal stress-activated protein kinases (JNKs) was higher in males than in females. Phosphorylation of extracellular signal-regulated kinases (ERKs) was lower in males than in females. Post- ischemia medullary infiltration of RAW 264.7 cell, a monocyte-macrophage cell, and intercellular adhesion molecule-1 (ICAM-1) were greater in males than in females. In conclusion, males were much more susceptible to ischemia than females. The enhanced propensity to ischemic injury in males was correlated with greater activation of JNKs, greater expression of ICAM-1, and greater trapping of leukocytes in the medulla.

• The Korean Journal of Physiology and Pharmacology
• /
• v.8 no.4
• /
• pp.187-194
• /
• 2004

Middle cerebral artery occlusion (MCAO) results in cell death by activation of complex signal pathways for cell death and survival. Hypothermia is a robust neuroprotectant, and its effect has often been attributed to various mechanisms, but it is not yet clear. Upstream from the cell death promoters and executioners are several enzymes that may activate several transcription factors involved in cell death and survival. In this study, we immunohistochemically examined the phosphorylation of mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 kinase during early period of the ischemic injury, following 2 hours (h) of transient MCAO. Increased phosphorylation of ERK and p38 was observed in the vessels at 3 h, neuron-like cells at 6 and 12 h and glia-like cells at 12 h. Activation of JNK was not remarkable, and a few cells showed active JNK following ischemia. Phosphorylation of Elk-1, a transcription factor, was reduced by ischemic insult. Hypothermia attenuated the activation of ERK, p38 and JNK, and inhibited reduction of Elk-1. These data suggest that signals via different MAPK family members converge on the cell damage process and hypothermia protects the brain by interfering with these pathways.

• The Korean Journal of Physiology and Pharmacology
• /
• v.6 no.6
• /
• pp.319-325
• /
• 2002

The induction of interleukin-6 (IL-6) using combined proinflammatory agents $(LPS/IFN-{\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ was studied in relation to p38 mitogen-activated protein kinase (MAPK) and $NF-{\kappa}B$ transcriptional factor in primary neonatal cardiomyocytes. When added to cultures of cardiomyocytes, the combined agents $(LPS/IFN-[\gamma}\;or\;TNF-{\alpha}/IFN-{\gamma})$ had stimulatory effect on the production of IL-6 and the elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. SB203580 inhibited protein production and gene expression of IL-6 in a concentration-dependent manner. In this study, $IFN-{\gamma}$ enhancement of $TNF-{\alpha}-induced\;NF-{\kappa}B$ binding affinity as well as p38 MAP kinase activation was observed. However, a specific inhibitor of p38 MAPK, SB203580, had no effect on $TNF-{\alpha}/IFN-{\gamma}\;or\;LPS/IFN-{\gamma}-induced\;NF-{\kappa}B$ activation. This study strongly suggests that these pathways about $TNF-{\alpha}/IFN-{\gamma}$ or $LPS/IFN-{\gamma}-activated$ IL-6 release can be primarily dissociated in primary neonatal cardiomyocytes.

• The Korea Journal of Herbology
• /
• v.22 no.1
• /
• pp.111-117
• /
• 2007

Objectives : The purpose of this study was to investigate the anti-inflammatory effects of extract from Pulsatilla koreana $N_{AKAI}$ (PK) on the peritoneal macrophage. Methods : To evaluate of anti-inflammatory of PK, we examined cytokines and NO production in lipopolysacchride (LPS)-induced macrophages. Furthermore, we examined molecular mechanism using western blot. Results : 1.Extract from PK reduced LPS-induced NO, tumor necrosis factor-a ($TNF-{\alpha}$), interleukin (IL)-6 and IL-12 production in peritoneal macrophages. 2.Extract from PK itself does not have any cytotoxic effect. PK inhibited the activation of extracelluar signal-regulated kinase(ERK 1/2) but not another mitogen-activated protein kinases (MAPKs) such as p38, c-Jun NH2-terminal kinase (JNK) and the degradation of inhibitory kappa B a ($I_{k}B_{a}$) does not any effect in the LPS-stimulated peritoneal macrophages. Conclusion : PK down-regulated LPS-induced NO and cytokines production, which may be provide a clinical basis for anti-inflammatory properties of PK.

• Biomedical Science Letters
• /
• v.12 no.3
• /
• pp.217-224
• /
• 2006

It has been reported that the dysfunctions of podocytes are associated with the development of diabetic nephropathy. In addition, insulin-like growth factors (IGFs) are associated with the development of diabetic nephropathy. However, it is not yet known about the effect of high glucose on IGF-I, -II secretion, and IGF binding proteins (IGFBPs) expression in the podocytes. Thus, this study was conducted to examine the effect of high glucose on IGF system and its involvement of protein kinase C (PKC) and mitogen activated protein kinases (MAPKs) in podocytes. In this study, high glucose (25 mM) increased IGF-I and IGF-II secretion (P<0.05), which was blocked by SB 203580 (a p38 MAPK inhibitor) but not by PD 98059 (a p44/42 MAPK inhibitor). In addition, high glucose-induced stimulation of IGFs was blocked by bisindolylmaleimide I and staurosporine (protein kinase C inhibitors). High glucose also increased IGFBP-l expression, which was blocked by bisindolylmaleimide I and SB 203580. In conclusion, high glucose alters IGFs secretion and IGFBP expression via PKC and p38 MAPK pathways in podocytes.

• BMB Reports
• /
• v.45 no.5
• /
• pp.293-298
• /
• 2012

The p38 mitogen-activated protein kinase (MAPK) is involved in various processes, including stress responses, development, and differentiation. However, little information on p38 MAPK in insects is available. In this study, a p38 MAPK gene, $Accp38b$, was isolated from $Apis$ $cerana$ $cerana$ and characterized. The quantitative real-time PCR (Q-PCR) analysis revealed that $Accp38b$ was induced by multiple stressors. Notably, the expression of $Accp38b$ was relatively higher in the pupae phase than in other developmental phases. During the pupae phase, Accp38b expression was higher in the thorax than in the head and abdomen and higher in the fat body than in the muscle and midgut. Immunohistochemisty showed significant positive staining of Accp38b in sections from the brain, eyes, fat body, and midgut of $A.$ $cerana$ $cerana$. These results suggest that Accp38b may play a crucial role in stress responses and have multiple aspects function during development.

• BMB Reports
• /
• v.49 no.7
• /
• pp.370-375
• /
• 2016

Ras oncoproteins are small molecular weight GTPases known for their involvement in oncogenesis, which operate in a complex signaling network with multiple effectors. Approximately 25% of human tumors possess mutations in a member of this family. The Raf1/MEK/Erk1/2 pathway is one of the most intensively studied signaling mechanisms. Different levels of regulation account for the inactivation of MAP kinases by MAPK phosphatases in a cell type- and stimuli-dependent manner. In the present study, using three inducible Ras-expressing NIH/3T3 cell lines, we demonstrated that MKP3 upregulation requires the activation of the Erk1/2 pathway, which correlates with the shutdown of this pathway. We also demonstrated, by applying pharmacological inhibitors and effector mutants of Ras, that induction of MKP3 at the protein level is positively regulated by the oncogenic Ras/Raf/MEK/Erk1/2 signaling pathway.