• Molecules and Cells
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• 제45권3호
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• pp.134-147
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• 2022

The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinetreated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress-and inflammation-related neurodegenerative disorders such as Parkinson's disease.

• 동의생리병리학회지
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• 제26권2호
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• pp.199-205
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• 2012

An extract of Alnus japonica (Betulaceae) cortex has been traditionally used for purifying blood, and curing feces containing blood, enteritis, diarrhea, alcoholism and cut wounds. In the present study, we demonstrated that the ethanol extract of Alnus japonica (EAJ) exhibited significantly cytotoxicity in human colon adenocarcinoma HT-29 cells. The results showed that the induction of apoptosis in HT-29 cells by EAJ was characterized by chromatin condensation and activation of caspase-3. EAJ-induced activation of caspase-9 and -3 caused the cleavage of poly ADP-ribose polymerase (PARP) and the release of cytochrome c. The expressions of Bcl-2 and Bid were reduced by EAJ in HT-29 cells, whereas pro-apoptotic protein Bak was increased in the cells. EAJ-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of MAP kinases (JNK and p38 MAPK), ASK1, and p53. NAC administration, a scavenger of ROS, reversed EAJ-induced cell death. In conclusion, these results indicated that EAJ can cause apoptosis through a ROS-mitochondria-caspases-dependent pathway in human HT-29 cells.

• 대한본초학회지
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• 제31권2호
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• pp.63-69
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• 2016

Objectives : The aerial parts of Agrimonia pilosa Ledeb (Agrimoniae Herba; AH) has been traditionally used as a Korean medicine to treatment of abdominal pain, sore throat, headaches, bloody discharge, parasitic infections and eczema. In this study, we investigated the effect of AH ethanol extract on lipopolysaccharide (LPS)-induced inflammation in RAW264.7 macrophage cells.Methods : AH was extracted by 30% ethanol (AH-E). Raw264.7 cells were treated with AH-E extract at different concentrations for 30 min and then stimulated with LPS (1㎍/㎖) or without for indicated times. Cell viability was measured by MTT assay, and nitric oxide (NO) production was measured by Griess assay. The expression of inflammatory mediators, iNOS and COX-2 and inflammatory cytokines, TNF-α, IL-1β, and IL-6 was detected by RT-PCR, and the phosphorylation of ERK1/2, p38 and JNK MAP kinases (MAPKs) was analyzed by Western blot. Also, the expression of NF-κB in nuclear and cytosol was detected by Western blot.Results : AH-E extract significantly decreased LPS-induced NO production in RAW264.7 cells. AH-E extract inhibited the mRNA expression of iNOS, COX-2, TNF-α, IL-1β, and IL-6 in LPS-stimulated cells with a dose-dependent manner. In addition, the phosphorylation of ERK, p38 and JNK MAPKs was also inhibited by AH-E extract. AP-E extract inhibited the nuclear translocation of NF-κB in LPS-stimulated cells.Conclusions : Our results suggest that AH-E extract has an anti-inflammatory activity in macrophages-mediated inflammation.

• BMB Reports
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• 제45권3호
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• pp.171-176
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• 2012

Receptor activator of NF-${\kappa}B$ ligand (RANKL) triggers the differentiation of bone marrow-derived monocyte/macrophage precursor cells (BMMs) of hematopoietic origin into osteoclasts through the activation of mitogen-activated protein (MAP) kinases and transcription factors. Recently, reactive oxygen species (ROS) and antioxidant enzymes were shown to be closely associated with RANKL-mediated osteoclast differentiation. Although glutaredoxin2 (Glrx2) plays a role in cellular redox homeostasis, its role in RANKL-mediated osteoclastogenesis is unclear. We found that Glrx2 isoform b (Glrx2b) expression is induced during RANKLmediated osteoclastogenesis. Over-expression of Glrx2b strongly enhanced RANKL- mediated osteoclastogenesis. In addition, Glrx2b-transduced BMMs enhanced the expression of key transcription factors c-Fos and NFATc1, but pre-treatment with SB203580, a p38-specific inhibitor, completely blocked this enhancement. Conversely, down-regulation of Glrx2b decreased RANKL- mediated osteoclastogenesis and the expression of c-Fos and NFATc1 proteins. Also, Glrx2b down-regulation attenuated the RANKL-induced activation of p38. Taken together, these results suggest that Glrx2b enhances RANKL-induced osteoclastogenesis via p38 activation.

• IMMUNE NETWORK
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• 제7권1호
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• pp.26-30
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• 2007

Background: Mycobacterial antigens released as PIM, LM, LAM, lipoproteins and other cellular factors may contribute to macrophage and dendritic cell activation through pattern recognition receptors such as TLRs. In this study, we assessed cytokine production and ERK activation with stimulation of several major mycobacterial antigens. Methods: Purified mycobacterial antigens (10, 22, 30, 38kDa) and recombinant antigens (6, 16, 19, 38kDa, Ag85A antigen) were studied. The production of cytokines (TNF-${\alpha}$, IL-12, IL-6) was measured by ELISA. The ERK activation was detected by western blotting. The expression of TLR2 or TLR4 was measured by flow cytometry. Results: Among purified antigens only 30kDa antigen induced production of IL-6 or TNF-${\alpha}$ in THP-1 macrophage cells. When THP-1 macrophage cells were treated with 30kDa antigen, phosphorylation of ERK was detected. ERK activation also occurred in TLR2 transfectant HEK293 cells with 30kDa antigen stimulation. Conclusion: 30kDa antigen is one of the major mycobacterial antigens inducing cytokine production and MAP kinases phosphorylation in macrophages.

• Asian Pacific Journal of Cancer Prevention
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• 제15권11호
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• pp.4405-4409
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• 2014

Reactive oxygen species (ROS), highly reactive molecules, are produced by living organisms as a result of normal cellular metabolism and environmental factors, and can damage nucleic acids and proteins, thereby altering their functions. The human body has several mechanisms to counteract oxidative stress by producing antioxidants. A shift in the balance between oxidants and antioxidants in favor of oxidants is termed as "oxidative stress". Paradoxically, there is a large body of research demonstrating the general effect of oxidative stress on signaling pathways, less is known about the initial and direct regulation of signaling molecules by ROS, or what we term the "oxidative interface." This review focuses on the molecular mechanisms through which ROS directly interact with critical signaling molecules to initiate signaling in a broad variety of cellular processes, such as proliferation and survival (MAP kinases and PI3 kinase), ROS homeostasis, and antioxidant gene regulation (Ref-1 and Nrf-2). This review also deals with classification as well as mechanisms of formation of free radicals, examining their beneficial and deleterious effects on cellular activities and focusing on the potential role of antioxidants in preventing and repairing damage caused by oxidative stress. A discussion of the role of phytochemical antioxidants in oxidative stress, disease and the epigenome is included.

• Molecules and Cells
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• 제23권1호
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• pp.30-38
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• 2007

Dipyrithione (2, 2'-dithiobispyridine-1, 1'-dioxide, PTS2), a pyrithione derivate, is highly bactericidal and fungicidal. In this study we examined its apoptotic effect on HeLa cells. PTS2 induced HeLa cell death in a dose and time dependent manner. ERK1/2 and p38 were markedly activated, but little JNK1/2 activation was detected. Suppression of p38 activation by SB203580 reduced the extent of apoptosis of the HeLa cells and also prevented induction of p21, release of cytochrome c, and cleavage of caspase-3 and PARP. Inhibition of ERK1/2 with PD98059 increased apoptosis, indicating that ERK1/2 activation has an anti-apoptotic effect on PTS2-induced HeLa cell apoptosis. PTS2 also inhibited murine sarcoma 180 and hepatoma 22 tumor growth in an animal tumor model. Our findings indicate that PTS2 possesses anti-tumor activity, that caspase-3 and poly (ADP-ribose) polymerase (PARP) are involved in PTS2-induced HeLa cell apoptosis and that ERK1/2 and p38 have opposing effects on this apoptosis.

• 한국식품과학회지
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• 제39권5호
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• pp.558-563
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• 2007

본 연구에서는 정상 세포인 간상피세포를 이용하여 BHT와 PG가 GJIC에 미치는 효과 및 그 작용 기전을 살펴보았다. BHT와 PG를 WB-F344세포에 각각 1.0mM, 0.75mM 이상 처리한 결과, 세포 생육이 80%이하로 저하되어 세포 독성을 보였고, BHT와 PG의 GJIC에 대한 억제효과는 이보다 낮은 농도인 0.6mM, 0.1mM에서 나타났으며 처리에 따른 Cx43 단백질의 발현 및 인산화를 측정한 결과, BHT와 PG 모두 농도의존적으로 Cx43의 인산화가 증가하였고, Cx43의 구조적 변화와 관련된 MAP kinase는 주요 biomarker인 ERK, p38, JNK의 발현 및 인산화를 측정한 결과, 농도의존적으로 ERK와 p38의 인산화가 증가하는 것으로 나타났다. 이는 WB-F344세포에 BHT와 PG의 처리가 세포독성을 나타내기 전 농도에서 GJIC의 억제하였음을 의미하며 이는 식품첨가물의 안전성 평가에도 활용될 수 있을 것으로 기대된다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.110-113
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• 2005

Under the condition of nutritional deprivation, actively growing cells prepare to enter $G_0$-like stationary phase. Protein modification by phosphorylation/dephosphorylation or ubiqutination contributes to transfer cells from active cell cycle to dormant stage. We show here that Psp1/Sds23, which functions in association with the 20S cyclosome/APC (1) and is essential for cell cycle progression in Schizosaccharomyces pombe (2), is phosphorylated by stress-activated MAP kinase Sty1 and protein kinase A, as well as Cdc2/cyclinB, upon entry into stationary phase. Three serines at the positions 18,333 and 391 are phosphorylated and overexpression of Psp1 mutated on these sites causes cell death in stationary phase. These modifications are required for the binding of Spufd2, a S.pombe homolog of multiubiquitin chain assembly factor E4 in ubiquitin fusion degradation pathway. Deletion of Spufd2 gene led to increase cell viability in stationary phase, indicating that S. pombe Ufd2 functions to inhibit cell growth at this stage to maintain cell viability. Moreover, Psp1 enhances the multiubiquitination function of Ufd2, suggesting that Psp1 phosphorylated by sty1 and PKA kinases is associated with the Ufd2-dependent protein degradation pathway, which is linked to stress tolerance, to maintain cell viability in the $G_0$-like stationary phase.

• Biomolecules & Therapeutics
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• 제21권5호
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• pp.332-337
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• 2013

Microglial activation plays an important role in the development and progression of various neurological disorders such as cerebral ischemia, multiple sclerosis, and Alzheimer's disease. Thus, controlling microglial activation can serve as a promising therapeutic strategy for such brain diseases. In the present study, we showed that kalopanaxsaponin A, a triterpenoid saponin isolated from Kalopanax pictus, inhibited inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor (TNF)-${\alpha}$ expression in lipopolysaccharide (LPS)-stimulated microglia, while kalopanaxsaponin A increased anti-inflammatory cytokine interleukin (IL)-10 expression. Subsequent mechanistic studies revealed that kalopanaxsaponin A inhibited LPS-induced DNA binding activities of NF-${\kappa}B$ and AP-1, and the phosphorylation of JNK without affecting other MAP kinases. Furthermore, kalopanaxsaponin A inhibited the intracellular ROS production with upregulation of anti-inflammatory hemeoxygenase-1 (HO-1) expression. Based on the previous reports that JNK pathway is largely involved in iNOS and proinflammatory cytokine gene expression via modulating NF-${\kappa}B$/AP-1 and ROS, our data collectively suggest that inhibition of JNK pathway plays a key role in anti-inflammatory effects of kalopanaxsaponin A in LPS-stimulated microglia.