• 생명과학회지
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• 제21권11호
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• pp.1549-1557
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• 2011

TRAIL은 다양한 암세포에서 apoptosis를 유발하는 것으로 알려져 있으나 간암세포를 포함한 일부 암세포에서 TRAIL 저항성이 획득된 것으로 보고되어지고 있다. 대두의 대표적인 생리활성 물질인 isoflavonoid계열 genistein은 이미 많은 암세포에서 apoptotic 효능을 가진 것으로 알려져 있으나 TRAIL에 의한 apoptosis 유도에 미치는 영향과 기전에 대한 연구는 여전히 미비한 실정이다. 본 연구에서는 TRAIL 저항성을 가진 Hep3B 간암세포에서 TRAIL에 의한 apoptosis 유도를 genistein이 더욱 상승시킬 수 있음을 보고하고자 한다. 본 연구의 결과에 의하면, Hep3B 세포에 세포독성을 보이지 않는 범위의 genistein에 의한 TRAIL 유도 apoptosis 상승효과는 미토콘드리아의 기능 손상과 연관성이 있었다. 또한 genistein과 TRAIL 복합처리에 의한 apoptosis 유도는 p38 MAPK 활성 저하로 더욱 상승하였으며, 이는 Bid의 truncation 증가, pro-apoptotic 단백질인 Bax의 발현 증가와 anti-apoptotic Bcl-2의 발현 감소 및 미토콘드리아에서 세포질로의 cytochrome c 유출의 증가와 연관성이 있었다. 또한 p38 MAPK 억제제는 genistein 및 TRAIL 복합처리에 의한 caspase의 활성 증가와 PARP 단백질의 단편화를 촉진시켰으며, 이는 미토콘드리아의 기능적 손상 증가에 의한 것임을 알 수 있었다. 따라서 본 연구의 결과는 genistein이 TRAIL에 의한 apoptosis 유도를 효과적으로 증가시킬 수 있으며, 이러한 과정이 p38 MAPK 의존적으로 이루어짐을 알 수 있었다.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.491-496
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• 2009

Skeletal muscle atrophy is a common phenomenon during the prolonged muscle disuse caused by cast immobilization, extended aging states, bed rest, space flight, or other factors. However, the cellular mechanisms of the atrophic process are poorly understood. In this study, we investigated the involvement of mitogen-activated protein kinase (MAPK) in the expression of muscle-specific RING finger 1 (MuRF1) during atrophy of the rat gastrocnemius muscle. Histological analysis revealed that cast immobilization induced the atrophy of the gastrocnemius muscle, with diminution of muscle weight and cross-sectional area after 14 days. Cast immobilization significantly elevated the expression of MuRF1 and the phosphorylation of p38 MAPK. The starvation of L6 rat skeletal myoblasts under serum-free conditions induced the phosphorylation of p38 MAPK and the characteristics typical of cast-immobilized gastrocnemius muscle. The expression of MuRF1 was also elevated in serum-starved L6 myoblasts, but was significantly attenuated by SB203580, an inhibitor of p38 MAPK. Changes in the sizes of L6 myoblasts in response to starvation were also reversed by their transfection with MuRF1 small interfering RNA or treatment with SB203580. From these results, we suggest that the expression of MuRF1 in cast-immobilized atrophy is regulated by p38 MAPK in rat gastrocnemius muscles.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8539-8548
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• 2014

Mitogen-activated protein kinase (MAPK) is an important signaling pathway in living beings in response to extracellular stimuli. There are 5 main subgroups manipulating by a set of sequential actions: ERK(ERK1/ERK2), c-Jun N(JNK/SAPK), p38 MAPK($p38{\alpha}$, $p38{\beta}$, $p38{\gamma}$ and $p38{\delta}$), and ERK3/ERK4/ERK5. When stimulated, factors of upstream or downstream change, and by interacting with each other, these groups have long been recognized to be related to multiple biologic processes such as cell proliferation, differentiation, death, migration, invasion and inflammation. However, once abnormally activated, cancer may occur. Several components of the MAPK network have already been proposed as targets in cancer therapy, such as p38, JNK, ERK, MEK, RAF, RAS, and DUSP1. Among them, alteration of the RAS-RAF-MEK-ERK-MAPK(RAS-MAPK) pathway has frequently been reported in human cancer as a result of abnormal activation of receptor tyrosine kinases or gain-of-function mutations in genes. The reported roles of MAPK signaling in apoptotic cell death are controversial, so that further in-depth investigations are needed to address these controversies. Based on an extensive analysis of published data, the goal of this review is to provide an overview on recent studies about the mechanism of MAP kinases, and how it generates certain tumors, as well as related treatments.

• BMB Reports
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• 제44권10호
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• pp.659-664
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• 2011

As part of the search for biologically active anti-osteoporotic agents that enhance differentiation and mineralization of osteoblastic MC3T3-E1 cells, we identified the ginsenoside Rh2(S), which is an active component in ginseng. Rh2(S) stimulates osteoblastic differentiation and mineralization, as manifested by the up-regulation of differentiation markers (alkaline phosphatase and osteogenic genes) and Alizarin Red staining, respectively. Rh2(S) activates p38 mitogen-activated protein kinase (MAPK) in time- and concentration-dependent manners, and Rh2(S)-induced differentiation and mineralization of osteoblastic cells were totally inhibited in the presence of the p38 MAPK inhibitor, SB203580. In addition, pretreatment with Go6976, a protein kinase D (PKD) inhibitor, significantly reversed the Rh2(S)-induced p38 MAPK activation, indicating that PKD might be an upstream kinase for p38 MAPK in MC3T3-E1 cells. Taken together, these results suggest that Rh2(S) induces the differentiation and mineralization of MC3T3-E1 cells through activation of PKD/p38 MAPK signaling pathways, and these findings provide a molecular basis for the osteogenic effect of Rh2(S).

• BMB Reports
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• 제45권5호
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• pp.293-298
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• 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.

• Journal of Ginseng Research
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• 제43권3호
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• pp.394-401
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• 2019

Background: Ginsenoside Rb1, a triterpene saponin, is derived from the Panax ginseng root and has potent antiinflammatory activity. In this study, we determined if Rb1 can increase macrophage phagocytosis and elucidated the underlying mechanisms. Methods: To measure macrophage phagocytosis, mouse peritoneal macrophages or RAW 264.7 cells were cultured with fluorescein isothiocyanate-conjugated Escherichia coli, and the phagocytic index was determined by flow cytometry. Western blot analyses were performed. Results: Ginsenoside Rb1 increased macrophage phagocytosis and phosphorylation of p38 mitogenactivated protein kinase (MAPK), but inhibition of p38 MAPK activity with SB203580 decreased the phagocytic ability of macrophages. Rb1 also increased Akt phosphorylation, which was suppressed by LY294002, a phosphoinositide 3-kinase inhibitor. Rb1-induced Akt phosphorylation was inhibited by SB203580, (5Z)-7-oxozeaenol, and small-interfering RNA (siRNA)-mediated knockdown of $p38{\alpha}$ MAPK in macrophages. However, Rb1-induced p38 MAPK phosphorylation was not blocked by LY294002 or siRNA-mediated knockdown of Akt. The inhibition of Akt activation with siRNA or LY294002 also inhibited the Rb1-induced increase in phagocytosis. Rb1 increased macrophage phagocytosis of IgG-opsonized beads but not unopsonized beads. The phosphorylation of p21 activated kinase 1/2 and actin polymerization induced by IgG-opsonized beads and Rb1 were inhibited by SB203580 and LY294002. Intraperitoneal injection of Rb1 increased phosphorylation of p38 MAPK and Akt and the phagocytosis of bacteria in bronchoalveolar cells. Conclusion: These results suggest that ginsenoside Rb1 enhances the phagocytic capacity of macrophages for bacteria via activation of the p38/Akt pathway. Rb1 may be a useful pharmacological adjuvant for the treatment of bacterial infections in clinically relevant conditions.

• Clinical and Experimental Reproductive Medicine
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• 제48권3호
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• pp.211-220
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• 2021

Objective: The present study aimed to investigate the possibility that curcumin (CMN) protects against methotrexate (MTX)-induced testicular damage by affecting the phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Methods: Eighteen male Wistar albino rats were randomly divided into three groups. The control group was given an intragastric administration of dimethyl sulfoxide (DMSO) daily for 14 days, the MTX group was given a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day, and the MTX+CMN group was given intragastric CMN (100 mg/kg/day, dissolved in DMSO) for 14 days and a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day. At the end of the experiment, all animals were sacrificed and the testicular tissues were removed for morphometry, histology, and immunohistochemistry. Body and testicular weights were measured. Results: Body weights, seminiferous tubule diameter, and germinal epithelium height significantly decreased in the MTX group compared to the control group. Whereas, the number of histologically damaged seminiferous tubules and interstitial space width significantly increased in the MTX group. In addition, the number of p-p38 MAPK immunopositive cells and the immunoreactivity of NF-κB also increased in the MTX group compared to the control group. CMN improved loss of body weight, morphometric values, and histological damage due to MTX. CMN also reduced the number of p-p38 MAPK immunopositive cells and the NF-κB immunoreactivity. Conclusion: CMN may reduce MTX-induced testicular damage by suppressing the p38 MAPK and NF-κB signaling pathways.

• The Korean Journal of Physiology and Pharmacology
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• 제6권6호
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• pp.319-325
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• 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.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.133-133
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• 2001

It is well known that p38 mitogen-activated protein kinase (p38MAPK) participates in cellular responses to mitogenic stimuli, environmental and genotoxic stresses, and apoptotic agents. Although there are several reports on p38MAPK in relation to cell growth and apoptosis, the exact mechanism of p38MAPK-mediated cell growth regulation remains obscure.(omitted)

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.338.2-338.2
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• 2002

Ceramide is a lipid second messenger that is involved in apoptotic cell death. In this study, we show that p38 MAPK plays an important role in the regulation of ceramide-induced apoptosis. We found that SB203580, a p38 kinase inhibitor, blocked the effects of ceramide to induce Bax translocation to mitochondria, activation of caspase-3, and DNA fragmentation. Furthermore. expression of a dominant negative form of p38 MAPK suppressed ceramide-induced Bax translocation, suggesting that p38 kinase activity is essential for Bax translocation. (omitted)