• Animal cells and systems
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• 제9권3호
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• pp.173-179
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• 2005

Cyclic-AMP-dependent protein kinase (PKA) seems to function as a negative regulator of the c-Jun $NH_2-terminal$ kinase (JNK) signaling pathway. We demonstrate here that the activity of the PKA catalytic subunit (PKAc) is reduced in apoptotic PC12 pheochromocytoma cells. Apoptotic progress was inhibited by dibutyryl cyclic AMP (dbcAMP), an analog of cAMP. The rescue by dbcAMP was attributable to inhibition of the JNK but not of the p38 signaling pathway, due to the induction of PKA activity. JNK was present in immunocomplexes of PKAc, and PKAc phosphorylated JNK in vitro. Presence of p38 kinase, however, was not prominent in immunocomplexes of PKAc. Our data suggest that JNK is a target point of negative regulation by PKAc in the JNK signaling pathway.

• BMB Reports
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• 제45권10호
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• pp.583-588
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• 2012

Leukotactin(Lkn)-1 is a CC chemokine and is upregulated in macrophages in response to Mycobacterium tuberculosis (MTB) infection. We investigated whether mitogen-activated protein kinases (MAPKs) are involved in MTB-induced expression of Lkn-1. The up-regulation of Lkn-1 by infection with MTB was inhibited in cells treated with inhibitors specific for JNK (SP600125) or p38 MAPK (SB202190). Since the up-regulation of Lkn-1 by MTB has been reported to be mediated by the PI3-K/PDK1/Akt signaling, we examined whether JNK and/or p38 MAPK are also involved in this signal pathway. MTB-induced Akt phosphorylation was blocked by treatment with JNK- or p38 MAPK-specific inhibitors implying that p38 and JNK are upstream of Akt. In addition, treatment with the PI3-K-specific inhibitor inhibited MTB-stimulated activation of JNK or p38 MAPK implying that PI3-K is upstream of JNK and p38 MAPK. These results collectively suggest that JNK and p38 MAPK are involved in the signal pathway responsible for MTB-induced up-regulation of Lkn-1.

• 한국자원식물학회지
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• 제36권3호
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• pp.191-197
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• 2023

Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, HSL increased p62/SQSTM1 expression. Inhibition of TLR4, p38, JNK, and NF-κB blocked HSL-mediated increase of p62/SQSTM1. HSL activated p38, JNK, and NF-κB signaling, but HSL-mediated activation of p38, JNK, and NF-κB signaling was reversed by TLR4 inhibition. In addition, HSL increased Nrf2 expression, but HSL-mediated Nrf2 expression did not occur in the inhibition of TLR4, p38, JNK, and NF-κB. Taken together, it is believed that HSL-mediated autophagy may be dependent on activating Nrf2 expression via TLR4-dependent activation of p38, JNK, and NF-κB in macrophages.

• 생명과학회지
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• 제19권8호
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• pp.1119-1124
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• 2009

포화 지방산이 인슐린 저항성 및 지방간등의 다양한 질병의 발병에 관련된다고 보고되고 있다. 그러나 간세포에서 포화지방산이 세포 사멸에 대한 효과 및 이와 관련된 신호전달계에 대해서는 거의 알려져 있지 않고 있다. 본 연구에서는 대표적인 포화지방산인 palmitic acid 처리 시 랫트 간세포 사멸에 미치는 효과와 이들이 mitogen activated protein kinases (MAPKs)와 관련되는 지를 알아보았다. 본 실험에서 palmitic acid 처리 시 간세포 성장은 억제 되었고 lactate dehydrogenase (LDH) 활성은 증가하였다. 이러한 작용은 JNK 및 p38 MAPK 억제제에 의해서 선택적으로 차단되었다. 아울러 palmitic acid에 의한 Bcl-2 발현 억제, Bax 발현 증가 작용, GSH 함량 감소작용 및 산화성 스트레스 증가작용 역시 JNK 및 p38 MAPK 억제제에 의해서 선택적으로 차단되었다. 실제로 palmitic acid 처리시 JNK 및 p38 MAPK 활성은 증가하였다. 결론적으로 palmitic acid는 간세포에서 JNK 및 p38 MAPK 활성을 경유하여 산화성 스트레스 증가를 통하여 간세포 사멸을 유도하는 것으로 나타났다.

• Tuberculosis and Respiratory Diseases
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• 제51권5호
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• pp.437-447
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• 2001

배 경 : TNF-$\alpha$는 UIP 환자의 폐 섬유화에 관계하는 cytokine으로 잘 알려져 있지만, 폐 섬유화를 일으키는 기전에 대해서는 알려져 있지 않다. TNF-$\alpha$에 의해 AP-1(c-jun N-terminal kinase, JNK의 하부 신호 전달체계) 같은 전사 인자가 활성화되고 이들에 의해서 PDGF 나 IGF-I fibrogenic cytokines의 전사가 관계있을 것으로 추측된다. 더구나 방사선에 의한 폐 섬유화 과정에서 JNK가 활성화되어 있는 것이 확인되었다. 본 연구의 목적은 UIP 환자에서 JNK의 활성도를 확인하고자 하였다. 방 법 : UIP 환자의 폐 조직과 대조군으로 이용된 폐암 환자의 정상 폐조직에서 phosphorous JNK (p-JNK), 대식세포의 표현자인 CD68, 그리고 cytokeratin을 이용하여 면역화학검사를 시행하였다. JNK의 in vitro kinase assay는 UIP 환자와 호흡기 증상이 없는 정상인에서 기관지 폐포세척술로 획득한 대식세포를 이용하였다. 결 과 : 면역조직화학검사에서 UIP 환자의 대부분의 폐포 대식세포는 p-JNK를 발현하였지만, 폐암 환자의 정상조직에서는 UIP 환자보다는 p-JNK 발현이 거의 없었다. 그러나 폐포 대식세포를 이용한 in vitro JNK kinase assay에서는 UIP 환자와 정상인 모두에서 JNK 활성도를 관찰할 수 없었다. 더구나 10 ng/mL의 TNF-$\alpha$로 자극하여도 JNK 활성도는 관찰할 수 없었다. 결 론 : UIP 환자의 폐 조직에서 JNK가 활성화되어 있음을 간접적으로 확인하였고, 추후 이들 활성화된 JNK와 fibrogenic cytokines과의 관계는 더 연구되어져야 할 과제로 생각된다.

• Journal of Veterinary Science
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• 제25권2호
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• pp.21.1-21.15
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• 2024

Background: Peste des petits ruminants (PPR) is a contagious and fatal disease of sheep and goats. PPR virus (PPRV) infection induces endoplasmic reticulum (ER) stress-mediated unfolded protein response (UPR). The activation of UPR signaling pathways and their impact on apoptosis and virus replication remains controversial. Objectives: To investigate the role of PPRV-induced ER stress and the IRE1-XBP1 and IRE1-JNK pathways and their impact on apoptosis and virus replication. Methods: The cell viability and virus replication were assessed by 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, immunofluorescence assay, and Western blot. The expression of ER stress biomarker GRP78, IRE1, and its downstream molecules, PPRV-N protein, and apoptosis-related proteins was detected by Western blot and quantitative reverse transcription-polymerase chain reaction, respectively. 4-Phenylbutyric acid (4-PBA) and STF-083010 were respectively used to inhibit ER stress and IRE1 signaling pathway. Results: The expression of GRP78, IRE1α, p-IRE1α, XBP1s, JNK, p-JNK, caspase-3, caspase-9, Bax and PPRV-N were significantly up-regulated in PPRV-infected cells, the expression of Bcl-2 was significantly down-regulated. Due to 4-PBA treatment, the expression of GRP78, p-IRE1α, XBP1s, p-JNK, caspase-3, caspase-9, Bax, and PPRV-N were significantly downregulated, the expression of Bcl-2 was significantly up-regulated. Moreover, in PPRV-infected cells, the expression of p-IRE1α, p-JNK, Bax, and PPRV-N was significantly decreased, and the expression of Bcl-2 was increased in the presence of STF-083010. Conclusions: PPRV infection induces ER stress and IRE1 activation, resulting in apoptosis and enhancement of virus replication through IRE1-XBP1s and IRE1-JNK pathways.

• Molecules and Cells
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• 제41권5호
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• pp.401-412
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• 2018

Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.88-88
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• 2022

In this study, we investigated the effect of Solanum nigrum aerial parts (SNAP) on macrophage activation and macrophage autophagy in RAW264.7 cells. SNAP increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. TLR4 inhibition blocked SNAP-mediated production of immunostimulatory factors. In addition, the JNK inhibition reduced the SNAP-mediated production of immunostimulatory factors, and the SNAP-mediated JNK activation was blocked by the TLR4 inhibition. SNAP activated macrophage autophagy. TLR4 inhibition blocked SNAP-mediated macrophage autophagy and inhibition of p38 and JNK attenuated SNAP-mediated macrophage autophagy. These findings indicate that SNAP may induce TLR4/JNK-mediated macrophage activation and TLR4/p38 and JNK-mediated macrophage autophagy.

• 동의생리병리학회지
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• 제21권1호
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• pp.76-81
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• 2007

The effect of either low or high intensity four weeks exercise treadmill running on the activation of the extracellular-signal regulated protein kinase (ERK1/2) and the c-Jun N-terminal kinase(JNK) pathways was determined in rat tibialis muscle. Sprague-Dawley rats were assigned to one of three groups: (i) sedentary group(NE; n=10); (ii) low intensity exercise group (8m/min; LIE; n=10); and (iii) high intensity exercise group(28m/min; HIE; n=10). The training regimens were planned so that animals covered the same distance and had similar glycogenutilization for both LIE and HIE exercise sessions. After four weeks exercise, 48 h after the last exercise bout obtained samples. pERK1 increased 1.5 times comparing with the sedentary group in the low intensity group while it increased 11.7 times in high intensity group, in the tibialis of rats. In the low intensity group, pERK2 increased 1.4 times comparing with the sedentary group while it increased 3.3 times in high intensity group. While pJNK1 decreased 0.9 times, comparing with the sedentary group, pJNK2 was increased to 0.5 times in the low intensity group. But in high intensity group, pJNK2 decreased 0.7 times while pJNK1 didn't show any change. In conclusion, Four weeks exercise of different intensities results in tibialis muscle activation of intracellular signal pathways, which may be one mechanism regulating specific adaptations induced by different exercise intensities.

• 대한약침학회지
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• 제6권2호
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• pp.77-90
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• 2003

The purpose of this study was to investigate the effect of Bee Venom on the lipopolysaccharide(LPS), sodium nitroprusside(SNP), hydrogen peroxide($H_2O_2$)-induced expressions of cyclooxygenase-2(COX-2), p38, jun N-terminal Kinase(JNK) and extra-signal response kinase(ERK) in RAW 264.7 cells, a murine macrophage cell line. Method : The expressions of COX-2, p38, JNK and ERK were determined by western blotting with corresponding antibodies. Results : 1. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly LPS and SNP-induced expression of COX-2 compared with control, respectively. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited insignificantly $H_2O_2$-induced expression of COX-2 compared with control, respectively. 2. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly LPS, SNP and $H_2O_2$-induced expression of p38 compared with control, respectively. 3. The 1 and $5\;{\mu}g/ml$ of bee venom inhibited significantly SNP-induced expression of JNK compared with control, respectively. All of bee venom inhibited insignificantly LPS and $H_2O_2$-induced expression of JNK compared with control, respectively. 4. The $5\;{\mu}g/ml$ of bee venom inhibited significantly SNP-induced expression of ERK, the $0.5\;{\mu}g/ml$ of bee venom increased significantly $H_2O_2$-induced expression of ERK compared with control. The 0.5, 1 and $5\;{\mu}g/ml$ of bee venom inhibited insignificantly LPS-induced expression of ERK compared with control, respectively.