• 대한의생명과학회지
• /
• 제18권4호
• /
• pp.369-376
• /
• 2012

Platycodon grandiflorum is a medicinal herb that is used to treat pulmonary and respiratory allergic disorders. The objective of this study was to investigate the protective effects of ethyl acetate extract of Platycodon grandiflorum (PGEA) against inflammation and to discern the molecular mechanism of PGEA in lipopolysaccharide (LPS)-induced signal pathways in RAW264.7 macrophage cells. PGEA suppressed the generation of nitric oxide (NO) and the expression of inducible NO synthase induced by LPS in RAW264.7 cells, and inhibited the release of pro-inflammatory cytokines induced by LPS in RAW264.7 cells. Western blot analysis showed that PGEA suppressed LPS-induced phosphorylation of p38 and c-Jun N-terminal kinase (JNK) but not extracellular signal-regulated kinase and $I{\kappa}-B{\alpha}$ degradation. Inactivation of JNK and p38 was effectively alleviated by PGEA, which subsequently affected the activation of c-Jun and c-Fos, which are the essential components of the activator protein-1 (AP-1) transcription complex. Taken together, the results indicate PGEA suppress the activation of p38, JNK, and AP-1, thereby inhibiting the generation of NO and pro-inflammatory cytokines, which affect the regulation of inflammation. PGEA may be useful for the treatment of various inflammatory diseases.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
• /
• pp.79-79
• /
• 2003

Recently diabetes has been found to be associated with metabolic bone diseases such as osteoporosis. In the present study, attempts have been made-to explore the effect of high glucose in bone formation. Osteoblast-like UMR 106 cells were treated with high glucose (22mM, 33mM, 44mM) for 1 or 2 days. High glucose significantly inhibited proliferation of UMR106 cells in a time- and dose- dependent manner as evidenced by MTT assay. For the evaluation of collagen synthesis, UMR 106 cells were cultured in high glucose media (44mM) for 24 h and the ratio of collagen content to total protein was measured. In addition, gene expression pattern of type I collagen was assessed by RT-PCR. The high concentration of glucose inhibited a collagen synthesis, a marker of bone formation activity. JNK, c- Jun N-terminal Kinase, is known to play an important role in stress-associated cell death. In this regard, we tested to determine whether high glucose has any effect on JNK activity. It has been found that treatment of high glucose induced phosphorylation of JNK. On the other hand, ERK phosphorylation was inhibited by high glucose in a dose-dependent manner. Taken together, Therefore these results indicate that inhibition of proliferation in UMR 106 cells following high glucose is related to JNK/ERK containing signal pathways. This study showed high glucose concentration could alter the bone metabolism leading to defective bone formation, suggesting that high glucose due to diabetes may playa significant role in the development of metabolic bone disease.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권10호
• /
• pp.5805-5810
• /
• 2013

This study was conducted to analyze the molecular mechanisms responsible for anti-proliferation effects of glaucocalyxin A in cultured MCF-7 and Hs578T breast cancer cells. The concentration that reduced cell viability to 50% (IC50) after 72 h treatment was derived and potential molecular mechanisms of anti-proliferation using the IC50 were investigated as changes in cell cycle arrest and apoptosis. Gene and protein expression changes related to apoptosis were investigated by semi-quantitative RT-PCR and western blotting, respectively. Involvement of phosphorylated mitogen-activated protein kinases and JNK signaling in regulation of these molecules was characterized by western blotting. Cell viability decreased in a concentration-dependent manner and the IC50 was determined as $1{\mu}M$ in MCF-7 and $4{\mu}M$ in Hs578T cell. Subsequently, we demonstrated that the GLA-induced MCF-7 and Hst578T cell death was due to cell cycle arrest at the G2/M transition and was associated with activation of the c-jun N-terminal kinase (JNK) pathway. We conclude that GLA has the potential to inhibit the proliferation of human breast cancer cells through the JNK pathway and suggest its application forthe effective therapy for patients with breast cancer.

• 대한물리치료과학회지
• /
• 제13권2호
• /
• pp.129-135
• /
• 2006

Vascular smooth muscle contraction is mediated by activation of extracellular signal-regulated kinase (ERK) 1/2, an isoform of mitogen-activated protein kinase (MAPK). However, the role of stress-activated protein kinase/c-Jun N-terminal kinase (JNK) in vascular smooth muscle contraction has not been defined. We investigated the role of JNK in the contractile response to norepinephrine (NE) in rat aortic smooth muscle. NE evoked contraction in a dose-dependent manner, and this effect was inhibited by the JNK inhibitor SP600125. NE increased the phosphorylation of JNK, which was greater in aortic smooth muscle from hypertensive rats than from normotensive rats. NE-induced JNK phosphorylation was significantly inhibited by SP600125 and the conventional-type PKC (cPKC) inhibitor Go6976, but not by the Rho kinase inhibitor Y27632 or the phosphatidylinositol 3-kinase inhibitor LY294002. Thymeleatoxin, a selective activator of cPKC, increased JNK phosphorylation, which was inhibited by $G{\ddot{o}}6976$. SP600125 attenuated the phosphorylation of caldesmon, an actin-binding protein whose phosphorylation is increased by NE. These results show that JNK contributes to NE-mediated contraction through phosphorylation of caldesmon in rat aortic smooth muscle, and that this effect is regulated by the PKC pathway, especially cPKC.

• The Korean Journal of Physiology and Pharmacology
• /
• 제28권3호
• /
• pp.239-252
• /
• 2024

Dexmedetomidine displays multiple mechanisms of neuroprotection in ameliorating ischemic brain injury. In this study, we explored the beneficial effects of dexmedetomidine on blood-brain barrier (BBB) integrity and neuroinflammation in cerebral ischemia/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) for 1.5 h and reperfusion for 24 h to establish a rat model of cerebral ischemia/reperfusion injury. Dexmedetomidine (9 ㎍/kg) was administered to rats 30 min after MCAO through intravenous injection, and SB203580 (a p38 MAPK inhibitor, 200 ㎍/kg) was injected intraperitoneally 30 min before MCAO. Brain damages were evaluated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin-eosin staining, Nissl staining, and brain water content assessment. BBB permeability was examined by Evans blue staining. Expression levels of claudin-5, zonula occludens-1, occludin, and matrix metalloproteinase-9 (MMP-9) as well as M1/M2 phenotypes-associated markers were assessed using immunofluorescence, RT-qPCR, Western blotting, and gelatin zymography. Enzyme-linked immunosorbent assay was used to examine inflammatory cytokine levels. We found that dexmedetomidine or SB203580 attenuated infarct volume, brain edema, BBB permeability, and neuroinflammation, and promoted M2 microglial polarization after cerebral ischemia/reperfusion injury. Increased MMP-9 activity by ischemia/reperfusion injury was inhibited by dexmedetomidine or SB203580. Dexmedetomidine inhibited the activation of the ERK, JNK, and p38 MAPK pathways. Moreover, activation of JNK or p38 MAPK reversed the protective effects of dexmedetomidine against ischemic brain injury. Overall, dexmedetomidine ameliorated brain injury by alleviating BBB permeability and promoting M2 polarization in experimental cerebral ischemia/reperfusion injury model by inhibiting the activation of JNK and p38 MAPK pathways.

• 한국자원식물학회지
• /
• 제33권3호
• /
• pp.183-193
• /
• 2020

Recently, as a natural substance has been emphasized interest in research to enhance the immune function. Green lettuce (Lactuca sativa L.) is a popular vegetable used fresh and it contains various phytochemicals and antioxidant compounds, and has been reported to have various physiological activities such as antibacterial, antioxidant, antitumor and anti-mutagenic. However, only a few studies have investigated on the mechanism of action of immune-enhancing activity of lettuce. Therefore, in this study, the immunomodulatory activities and potential mechanism of action of Green lettuce extracts (GLE) were evaluated in the murine macrophage cell line RAW264.7. GLE significantly increased NO levels by RAW264.7 cells, as well as expressions of immunomodulators such as iNOS, COX-2, IL-1β, IL-6, IL-12, TNF-α and MCP-1. Although GLE activated ERK1/2, p38, JNK and NF-κB, GLE-mediated expressions of immunomodulators was dependent on p38, JNK and NF-κB. In addition, TLR4 inhibition blocked GLE-mediated expressions of immunomodulators and activation of p38, JNK and NF-κB. Taken together, these results demonstrated that TLR4-MAPK/NF-κB signalling pathways participated in GLE-induced macrophage activation and GLE could be developed as a potential immunomodulating functional food.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2022년도 추계학술대회
• /
• pp.89-89
• /
• 2022

Paeonia lactiflora (P. lactiflora) is a medicinal plant widely used for treating inflammatory diseases. However, P. lactiflora has been recently reported to increase the production of proinflammatory mediators and activates phagocytosis in macrophages. Thus, in this study, we tried to verify the macrophage activation of Paeoniae Radix Alba (PRR, also known as red peony root) and elucidate its mechanism of action. PRR upregulated the production of proinflammatory mediators and activated phagocytosis in RAW264.7 cells. However, these effects were reversed by inhibition of TLR2/4. In addition, the inhibition of p38, JNK, and ERK1/2 reduced the PRR-mediated production of proinflammatory mediators, and the SPL-mediated activation of p38, JNK, and ERK1/2 was blocked by the TLR4 inhibition. These findings indicate that PRR may activate macrophages through TLR4-dependent activation of p38, JNK, and ERK1/2. These indicate that PRR has immunostimulatory activity. Thus, it is believed that PRR can be used as a functional food agent that enhances the immune system.

• 생명과학회지
• /
• 제24권1호
• /
• pp.8-13
• /
• 2014

여성에게 특히 높은 발병률을 보이는 유방암은 다양한 인자에 의해 암세포 침투와 전이가 발생한다. 그중에서 MMP-9은 유방암에서 높은 발현율을 나타내며, 유방암 세포의 침투와 전이에 주요하게 작용한다. MMP-9은 다양한 성장인자와 사이토카인, PMA 등에 의해 발현이 유도되며 세포 내 자연적으로 발생된 내생적 억제인자인 TIMP-1과 -2에 의해 그 활성 및 발현이 조절된다. MMP-9의 활성 및 발현을 저해하기 위해 사용한 물질은 모링가 추출물로 모링가의 모든 부위가 다양한 질환을 치료하는 것으로 알려져 있다. 이 연구에서는 대표적으로 모링가씨, 뿌리, 잎, 열매 추출물질을 이용하여 MMP-9의 활성억제 유무를 연구하였으며, MCF-7 세포에서 모링가 뿌리추출물이 MMP-9을 가장 효과적으로 억제하였다. 또한 MDA-MB-231을 이용한 비교실험에서도 세포특이성 없이 MMP-9의 활성 및 발현이 모링가 뿌리 추출물에 의해 억제되었고 단백질과 mRNA 발현에서도 동일한 결과가 도출되었다. 뿐만 아니라 암세포 침투실험에서도 모링가 뿌리 추출물에 의해 암세포 침투가 50% 이상 감소 되었으나, TIMP-1과 -2 mRNA 발현은 모링가 뿌리 추출물에 의해 저해되지 않았으므로 모링가 뿌리 추출물이 MMP-9 활성 및 발현 저해를 통해 암세포 침투를 저해시키는 것으로 예상된다. 그리고 MMP-9 활성 및 발현 조절기전을 확인하기 위해 MAP kinase의 인산화를 확인한 실험에서 모링가 뿌리 추출물이 ERK와 JNK의 인산화를 억제시킴을 확인하였다. 결론적으로 이 실험을 통해 모링가 추출물 중 뿌리 추출물이 MMP-9 활성 및 발현저해에 가장 효과적이며, ERK와 JNK의 인산화 조절을 통해 MMP-9의 활성 및 발현을 직접적으로 조절함을 확인할 수 있었다.

• 동의생리병리학회지
• /
• 제20권5호
• /
• pp.1211-1216
• /
• 2006

The effect of a chronic programme of either low- or moderate-to-high-intensity treadmill running on the activation of the Extracellular-signal regulated protein kinase (ERK1/2), Phosphorylated ERK 1/2(pERK1/2) and the Phosphorylated c-Jun N-terminal kinase(pJNK) pathways was determined in rat Back skin Hair follicle. Sprague-Dawley rats were assigned to one of three groups: (i) sedentary group(NE; n=10); (ii) low-intensity exercise group (Bm/min; LIE; n=10); and (iii) moderate-high-intensity exercise group(28m1min; HIE; n=10). The training regimens were planned so that animals covered the same distance and had similar utilization for both LIE and HIE exercise sessions. The report runs as follows; A single bout of LIE or HIE following 4 weeks of exercise led to a twofold increase in the phosphorylation of ERK2, pERK2 and a threefold increase in pJNKl, pERKl. ERKI phosphorylation in LIE Back skin sampled and pJNK2 in HIE Back skin sampled 48h after the last exercise bout was similar to sedentary values, while pJNK2 phosphorylation in LIE Back skin sampled was 70-80% lower than sedentary. 48h after the last exercise bout of LIE or HIE increased ERK2, pERKl and pJNKl expression, with the magnitude of this increase being independent of prior exercise intensity or duration. PERK1/2, pJNKl expression was increased Three- to fourfold in Back skin Hair follicle sampled 48h after the last exercise bout irrespective of the prior exercise programme, but ERKI expression in HIE Back skin sampled was approximately 90% lower than sedentary values. In conclusion, exercise-training of different jntensities/durations results in selective postexercise activation of intracellular signal pathways, which may be one mechanism regulating specific adaptations induced by diverse training programmes.

• Fisheries and Aquatic Sciences
• /
• 제21권5호
• /
• pp.14.1-14.8
• /
• 2018

The objective of this study was to investigate the anti-inflammatory effects of the pepsinolytic hydrolysate from the fish frame, Johnius belengerii, on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The J. belengerii frame hydrolysate (JFH) significantly suppressed nitric oxide (NO) secretion on LPS-stimulated RAW264.7 macrophages. Moreover, the JFH markedly inhibited the levels of protein and mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, the LPS-stimulated mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-6 was downregulated when cells were cultured with the JFH. The JFH significantly reduced the phosphorylation of c-Jun N-terminal kinase (JNK) and the translocation of nuclear factor-kappa B ($NF-{\kappa}B$) in macrophages. As the result, the JFH has the potential anti-inflammatory activity via blocking the JNK and $NF-{\kappa}B$ signal pathways.