1.Mechanism of Shaofu Zhuyu Decoction in treatment of endometriosis-associated dysmenorrhea with syndrome of cold coagulation and blood stasis based on MSK1/2.
Yuan-Huan CHEN ; Hai-Yan MAO ; Quan-Sheng WU ; Xiao-Hua ZHANG ; Jian SHEN ; Peng FENG ; Can-Can HUANG ; Xiu-Jia JI
China Journal of Chinese Materia Medica 2022;47(17):4674-4681
This study aims to decipher the mechanism underlying the effect of Shaofu Zhuyu Decoction on endometriosis(EMT)-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis based on mitogen-and stress-activated protein kinase 1/2(MSK1/2).We employed a random number table to randomly assign SPF female non-pregnant rats into the sham group, and treated the rest rats with autologous transplantation+refrigerator freezing for the modeling of the syndrome of cold coagulation and blood stasis.The modeled rats were then randomly assigned into the control group and high-, medium-and low-dose Shaofu Zhuyu Decoction groups.The rats in the low-, medium-, and high-dose decoction groups were respectively administrated with 9, 4.5, and 2.3 g·kg~(-1) decoction through gavage once a day for 2 consecutive weeks, and those in the control group were administrated with 0.24 mg·kg~(-1) gestrinone through gavage once every 3 days for 2 weeks.After that, the size of ectopic focus in each rat was measured via laparotomy.Enzyme-linked immunosorbent assay(ELISA) was adopted to determine the expression of interleukin(IL)-6, IL-10, prostaglandin E2(PGE2), tumor necrosis factor-α(TNF-α).Western blot was employed to determine the protein levels of MSK1/2 and dual-specificity phosphatase 1(DUSP1) and real-time quantitative polymerase chain reaction(RT-PCR) to determine the mRNA levels of the two genes in rat eutopic endometrial tissue.Compared with the sham group, the model group showed increased levels of IL-6, PGE2, and TNF-α while decrease level of IL-10 in the serum(P<0.01).Compared with the model group, the high-and medium-dose decoction groups and the gestrinone group had declined levels of IL-6, PGE2, and TNF-α while risen level of IL-10 in the serum(P<0.01).The model group had lower protein levels and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the sham group(P<0.01). The high-and medium-dose decoction groups and the gestrinone group had higher protein and mRNA levels of MSK1/2 and DUSP1 in the eutopic endometrial tissue than the model group(P<0.01).The results indicated that Shaofu Zhuyu Decoction can regulate the abnormal expression of pro-inflammatory cytokines TNF-α, IL-6, and PGE2 and anti-inflammatory cytokines IL-10 and DUSP1 via MSK1/2 to alleviate EMT-associated dysmenorrhea in rats with the syndrome of cold coagulation and blood stasis.
Animals
;
Female
;
Rats
;
Anti-Inflammatory Agents/therapeutic use*
;
Cytokines
;
Dinoprostone
;
Drugs, Chinese Herbal/therapeutic use*
;
Dual-Specificity Phosphatases
;
Dysmenorrhea/genetics*
;
Endometriosis/genetics*
;
Gestrinone/therapeutic use*
;
Interleukin-10
;
Interleukin-6
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Mitogens/therapeutic use*
;
RNA, Messenger
;
Tumor Necrosis Factor-alpha/metabolism*
2.Mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination in treatment of bronchial asthma based on network pharmacology and experimental verification.
Bei-Bei ZHANG ; Meng-Nan ZENG ; Qin-Qin ZHANG ; Ru WANG ; Ju-Fang JIA ; Peng-Li GUO ; Meng LIU ; Wei-Sheng FENG ; Xiao-Ke ZHENG
China Journal of Chinese Materia Medica 2022;47(18):4996-5007
This study aims to investigate mechanism of "Ephedrae Herba-Descurainiae Semen Lepidii Semen" combination(MT) in the treatment of bronchial asthma based on network pharmacology and in vivo experiment, which is expected to lay a theoretical basis for clinical application of the combination. First, the potential targets of MT in the treatment of bronchial asthma were predicted based on network pharmacology, and the "Chinese medicine-active component-target-pathway-disease" network was constructed, followed by Gene Oncology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment of the potential targets. Molecular docking was used to determine the binding activity of key candidate active components to hub genes. Ovalbumin(OVA, intraperitoneal injection for sensitization and nebulization for excitation) was used to induce bronchial asthma in rats. Rats were classified into control group(CON), model group(M), dexamethasone group(DEX, 0.075 mg·kg~(-1)), and MT(1∶1.5) group. Hematoxylin and eosin(HE), Masson, and periodic acid-Schiff(PAS) staining were performed to observe the effect of MT on pathological changes of lungs and trachea and goblet cell proliferation in asthma rats. The levels of transforming growth factor(TGF)-β1, interleukin(IL)6, and IL10 in rat serum were detected by enzyme-linked immunosorbent assay(ELISA), and the mRNA and protein levels of mitogen-activated protein kinase 8(MAPK8), cyclin D1(CCND1), IL6, epidermal growth factor receptor(EGFR), phosphatidylinositol 3-kinase(PI3 K), and protein kinase B(Akt) by qRT-PCR and Western blot. Network pharmacology predicted that MAPK8, CCND1, IL6, and EGFR were the potential targets of MT in the treatment of asthma, which may be related to PI3 K/Akt signaling pathway. Quercetin and β-sitosterol in MT acted on a lot of targets related to asthma, and molecular docking results showed that quercetin and β-sitosterol had strong binding activity to MAPK, PI3 K, and Akt. In vivo experiment showed that MT could effectively alleviate the symptoms of OVA-induced asthma rats, improve the pathological changes of lung tissue, reduce the production of goblet cells, inhibit the inflammatory response of asthma rats, suppress the expression of MAPK8, CCND1, IL6, and EGFR, and regulate the PI3 K/Akt signaling pathway. Therefore, MT may relieve the symptoms and inhibit inflammation of asthma rats by regulating the PI3 K/Akt signaling pathway, and quercetin and β-sitosterol are the candidate active components.
Animals
;
Asthma/drug therapy*
;
Cyclin D1
;
Dexamethasone/adverse effects*
;
Drug Combinations
;
Drugs, Chinese Herbal/therapeutic use*
;
Eosine Yellowish-(YS)/adverse effects*
;
Ephedra
;
ErbB Receptors
;
Hematoxylin/therapeutic use*
;
Interleukin-10
;
Interleukin-6
;
Mitogen-Activated Protein Kinase 8/therapeutic use*
;
Molecular Docking Simulation
;
Network Pharmacology
;
Ovalbumin/adverse effects*
;
Periodic Acid/adverse effects*
;
Phosphatidylinositol 3-Kinases
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Quercetin
;
RNA, Messenger
;
Rats
3.The effect of noise exposure on insulin sensitivity in mice may be mediated by the JNK/IRS1 pathway.
Lijie LIU ; Cong FANG ; Jing YANG ; Hongyu ZHANG ; Yi HUANG ; Chuanying XUAN ; Yongfang WANG ; Shengwei LI ; Jun SHA ; Mingming ZHA ; Min GUO
Environmental Health and Preventive Medicine 2018;23(1):6-6
BACKGROUND:
Epidemiological studies have suggested that noise exposure may increase the risk of type 2 diabetes mellitus (T2DM), and experimental studies have demonstrated that noise exposure can induce insulin resistance in rodents. The aim of the present study was to explore noise-induced processes underlying impaired insulin sensitivity in mice.
METHODS:
Male ICR mice were randomly divided into four groups: a control group without noise exposure and three noise groups exposed to white noise at a 95-dB sound pressure level for 4 h/day for 1, 10, or 20 days (N1D, N10D, and N20D, respectively). Systemic insulin sensitivity was evaluated at 1 day, 1 week, and 1 month post-noise exposure (1DPN, 1WPN, and 1MPN) via insulin tolerance tests (ITTs). Several insulin-related processes, including the phosphorylation of Akt, IRS1, and JNK in the animals' skeletal muscles, were examined using standard immunoblots. Biomarkers of inflammation (circulating levels of TNF-α and IL-6) and oxidative stress (SOD and CAT activities and MDA levels in skeletal muscles) were measured via chemical analyses.
RESULTS:
The data obtained in this study showed the following: (1) The impairment of systemic insulin sensitivity was transient in the N1D group but prolonged in the N10D and N20D groups. (2) Noise exposure led to enhanced JNK phosphorylation and IRS1 serine phosphorylation as well as reduced Akt phosphorylation in skeletal muscles in response to exogenous insulin stimulation. (3) Plasma levels of TNF-α and IL-6, CAT activity, and MDA concentrations in skeletal muscles were elevated after 20 days of noise exposure.
CONCLUSIONS
Impaired insulin sensitivity in noise-exposed mice might be mediated by an enhancement of the JNK/IRS1 pathway. Inflammation and oxidative stress might contribute to insulin resistance after chronic noise exposure.
Animals
;
Biomarkers
;
metabolism
;
Inflammation
;
physiopathology
;
Insulin Receptor Substrate Proteins
;
genetics
;
metabolism
;
Insulin Resistance
;
genetics
;
immunology
;
MAP Kinase Signaling System
;
physiology
;
Male
;
Mice
;
Mice, Inbred ICR
;
Mitogen-Activated Protein Kinase 8
;
genetics
;
metabolism
;
Noise
;
adverse effects
;
Oxidative Stress
;
physiology
;
Proto-Oncogene Proteins c-akt
;
genetics
;
metabolism
;
Random Allocation
;
Time Factors
4.alpha-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-Infected Gastric Epithelial AGS Cells.
Ji Hyun CHOI ; Soon Ok CHO ; Hyeyoung KIM
Yonsei Medical Journal 2016;57(1):260-264
The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.
Enzyme-Linked Immunosorbent Assay
;
Epithelial Cells/metabolism
;
Gastric Mucosa/*drug effects/metabolism/microbiology
;
Gene Expression Regulation, Bacterial
;
Helicobacter Infections/immunology/*metabolism
;
Helicobacter pylori/drug effects/*pathogenicity
;
Humans
;
Interleukin-8/genetics/*metabolism
;
JNK Mitogen-Activated Protein Kinases
;
Janus Kinase 1
;
Mitogen-Activated Protein Kinases/*biosynthesis
;
NF-kappa B/*metabolism
;
RNA, Messenger/isolation & purification/metabolism
;
Reactive Oxygen Species/metabolism
;
STAT3 Transcription Factor
;
Stomach/metabolism/*microbiology
;
Thioctic Acid/*pharmacology
5.27-O-(E)-p-coumaric acyl ursolic acid via JNK/SAPK signal pathway regulates apoptosis of human breast cancer MDA-MB-231 cell line.
China Journal of Chinese Materia Medica 2015;40(4):722-726
27-O-(E)-p-coumaric acyl ursolic acid( DY-17) from Ilex latifolia is a compound of the monomer. To investigate the DY-17 inducing apoptosis in the human breast cancer cell line, the MDA-MB-231 cells were used as research object in this experiment. The proliferation activity of the MDA-MB-231 cells stimulated with the different concentrations of DY-17 (20, 40 µmol · L(-1)) was detected at different time( 12, 24, 36, 48, 60,72 h) . We surveyed the DY-17 inducing apoptosis of the MDA-MB-231 cells with the fluorescent staining technology. The rate of MDA-MB-231 cells apoptosis and necrosis was determined by flow cell cytometry (FCC). Moreover, expression of JNK, phosphorylated JNK, Bax, PARP shear and caspase-3 shear related to JNK/SAPK pathways were investigated in every group ( control group, EGF group, EGF + DY-17 40 µmol · L(1) group and EGF + SP600125 group) with Western blot. The MTT results showed that, in the presence of DY-17, the proliferation activity of MDA-MB-231 cells decreased in a dose-dependent and time-dependent manner. The apoptosis and necrosis rates of MDA-MB-231 cells with DY-17(20, 40 µmol · L(-1)) groups was respectively 31.86%, 49.91% by flow cytometry and significantly increased compared with control group under Fluores- cence microscopy. Up-regulation of the JNK phosphorylation protein expression was observed in EGF group compared with control group. In addition, markedly decreased the expression of JNK phosphorylation protein were also surveyed in EGF + DY-17 40 µmol · L(-1) group compared with EGF group. The expression of Bax, shear PARP and shear caspase-3 protein in EGF + DY-17 40 µmol · L(-1) group were significantly increased in comparison with EGF group. The results showed DY-17 induced apoptosis of human breast cancer MDA-MB-231 cell line related to down-regulating JNK/SAPK signal pathways.
Apoptosis
;
drug effects
;
Breast Neoplasms
;
drug therapy
;
enzymology
;
genetics
;
Cell Line, Tumor
;
Cell Proliferation
;
drug effects
;
Drugs, Chinese Herbal
;
pharmacology
;
Female
;
Humans
;
MAP Kinase Kinase 4
;
genetics
;
metabolism
;
Mitogen-Activated Protein Kinase 8
;
genetics
;
metabolism
;
Signal Transduction
;
drug effects
;
Triterpenes
;
chemistry
;
pharmacology
6.Effects of hydrogen sulfide on myocardial fibrosis and MAPK1/3 and MMP-8 expression in diabetic rats.
Fang LI ; Ou ZENG ; Jian LUO ; Zhi-Xiong WU ; Ting XIAO ; Jing-Jing ZHANG ; Jun YANG
Journal of Southern Medical University 2015;35(4):549-552
OBJECTIVETo explore the effects of hydrogen sulfide (H(2)S) on myocardial fibrosis and expressions of MAPK1/3 and MMP-8 in diabetic rats.
METHODSForty adult male SD rats were randomized into 4 groups, namely the control group, diabetes mellitus group (STZ group), diabetes mellitus with H(2)S treatment group (STZ+H(2)S group), and normal rats with H(2)S treatment group (H(2)S group). Diabetes was induced by intraperitoneal injections of 40 mg/kg streptozotocin (STZ). The rats in the control group received daily intraperitoneal injections of saline, and those in STZ+H(2)S group and H(2)S group were given NaHS (100 µmol/kg) injections. After 8 weeks, the pathologies of cardiac fibrosis were examined with HE staining, and the expressions of collagen I, MAPK1/3 and MMP-8 were analyzed with Western blotting.
RESULTSCompared with the control group, the diabetic rats showed increased collagen content and obvious interstitial fibrosis in the myocardial tissue with significantly increased expression levels of collagen I, MAPK1/3 and MMP-8 (P<0.05); all these changes were obviously reversed by treatment with H(2)S (P<0.05). Collagen I, MAPK1/3 and MMP-8 expression levels and the degree of myocardial fibrosis were comparable between H(2)S group and control group (P>0.05).
CONCLUSIONHydrogen sulfide can attenuate cardiac fibrosis in diabetic rats, and the mechanism may involve the inhibition of MAPK1/3/MMP-8 signal pathway.
Animals ; Collagen Type I ; metabolism ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; Fibrosis ; Hydrogen Sulfide ; pharmacology ; Injections, Intraperitoneal ; Male ; Matrix Metalloproteinase 8 ; metabolism ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocardium ; pathology ; Rats ; Rats, Sprague-Dawley
7.Effect of osthol on apoptosis and bone resorption of osteoclasts cultured in vitro.
Lei-Guo MING ; Ming-Gang WANG ; Ke-Ming CHEN ; Jian ZHOU ; Gui-Qiu HAN ; Rui-Qing ZHU
Acta Pharmaceutica Sinica 2012;47(2):174-179
This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by 1 x 10(-5) mol x L(-1) osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNK1/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with 1 x 10(-5) mol x L(-1) osthol. There is significant difference between control group and experiment group treated by 1 x 10(-5) mol x L(-1) osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption.
Acid Phosphatase
;
metabolism
;
Animals
;
Apoptosis
;
drug effects
;
Bone Resorption
;
Cells, Cultured
;
Cnidium
;
chemistry
;
Coumarins
;
isolation & purification
;
pharmacology
;
Gene Expression
;
Isoenzymes
;
metabolism
;
Mitogen-Activated Protein Kinase 8
;
metabolism
;
Mitogen-Activated Protein Kinase 9
;
metabolism
;
Osteoclasts
;
metabolism
;
pathology
;
Osteoprotegerin
;
metabolism
;
Phosphorylation
;
Plants, Medicinal
;
chemistry
;
RANK Ligand
;
metabolism
;
Rabbits
;
Seeds
;
chemistry
;
Signal Transduction
;
Tartrate-Resistant Acid Phosphatase
8.Activation of c-Jun N-terminal kinase 1/2 regulated by nitric oxide is associated with neuronal survival in hippocampal neurons in a rat model of ischemia.
Xian-Wei ZENG ; Ming-Wei LI ; Jing PAN ; Tai-Ling JI ; Bin YANG ; Bo ZHANG ; Xiao-Qiang WANG
Chinese Medical Journal 2011;124(20):3367-3372
BACKGROUNDC-Jun N-terminal kinase (JNK) signaling pathway plays a critical role in cerebral ischemia. Although the mechanistic basis for this activation of JNK1/2 is uncertain, oxidative stress may play a role. The purpose of this study was to investigate whether the activation of JNK1/2 is associated with the production of endogenous nitric oxide (NO).
METHODSIschemia and reperfusion (I/R) was induced by cerebral four-vessel occlusion. Sprague-Dawley (SD) rats were divided into 6 groups: sham group, I/R group, neuronal nitric oxide synthase (nNOS) inhibitor (7-nitroindazole, 7-NI) given group, inducible nitric oxide synthase (iNOS) inhibitor (2-amino-5,6-dihydro-methylthiazine, AMT) given group, sodium chloride control group, and 1% dimethyl sulfoxide (DMSO) control group. The levels of protein expression and phospho-JNK1/2 were detected by Western blotting and the survival hippocampus neurons in CA1 zone were observed by cresyl violet staining.
RESULTSThe study illustrated two peaks of JNK1/2 activation occurred at 30 minutes and 3 days during reperfusion. 7-NI inhibited JNK1/2 activation during the early reperfusion, whereas AMT preferably attenuated JNK1/2 activation during the later reperfusion. Administration of 7-NI and AMT can decrease I/R-induced neuronal loss in hippocampal CA1 region.
CONCLUSIONJNK1/2 activation is associated with endogenous NO in response to ischemic insult.
Animals ; Blotting, Western ; Brain Ischemia ; enzymology ; Enzyme Inhibitors ; Hippocampus ; cytology ; metabolism ; Indazoles ; pharmacology ; Male ; Mitogen-Activated Protein Kinase 8 ; metabolism ; Mitogen-Activated Protein Kinase 9 ; metabolism ; Neurons ; cytology ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; antagonists & inhibitors ; Phosphorylation ; drug effects ; Rats ; Rats, Sprague-Dawley
9.Inhibitory effect of (-)-epigallocatechin gallate on titanium particle-induced TNF-alpha release and in vivo osteolysis.
Shan JIN ; Ju Young PARK ; Jung Min HONG ; Tae Ho KIM ; Hong In SHIN ; Eui Kyun PARK ; Shin Yoon KIM
Experimental & Molecular Medicine 2011;43(7):411-418
Tumor necrosis factor-alpha (TNF-alpha) and inflammatory cytokines released from activated macrophages in response to particulate debris greatly impact periprosthetic bone loss and consequent implant failure. In the present study, we found that a major polyphenolic component of green tea, (-)-epigallocatechin gallate (EGCG), inhibited Ti particle-induced TNF-alpha release in macrophages in vitro and calvarial osteolysis in vivo. The Ti stimulation of macrophages released TNF-alpha in a dose- and time-dependent manner, and EGCG substantially suppressed Ti particle-induced TNF-alpha release. Analysis of signaling pathway showed that EGCG inhibited the Ti-induced c-Jun N-terminus kinase (JNK) activation and inhibitory kappaB (IkappaB) degradation, and consequently the Ti-induced transcriptional activation of AP-1 and NF-kappaB. In a mouse calvarial osteolysis model, EGCG inhibited Ti particle-induced osteolysis in vivo by suppressing TNF-alpha expression and osteoclast formation. Therefore, EGCG may be a potential candidate compound for osteolysis prevention and treatment as well as aseptic loosening after total replacement arthroplasty.
Animals
;
Catechin/*analogs & derivatives/pharmacology
;
Cell Line
;
Implants, Experimental
;
Macrophages/drug effects/metabolism
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Mitogen-Activated Protein Kinase 8/metabolism
;
NF-kappa B/metabolism
;
Osteolysis/chemically induced/*metabolism/prevention & control
;
Particulate Matter/*adverse effects
;
Prosthesis Failure
;
Signal Transduction/drug effects
;
Skull/*drug effects/pathology
;
Titanium/*adverse effects
;
Transcription Factor AP-1/metabolism
;
Tumor Necrosis Factor-alpha/*metabolism
10.CSN1 inhibits c-Jun phosphorylation and down-regulates ectopic expression of JNK1.
Tomohiko TSUGE ; Suchithra MENON ; Yingchun TONG ; Ning WEI
Protein & Cell 2011;2(5):423-432
CSN1 is a component of the COP9 signalosome (CSN), a conserved protein complex with pleiotropic functions in many organs and cell types. CSN regulates ubiquitinproteasome dependent protein degradation via the deneddylation and the associated deubiquitination activities. In addition, CSN associates with protein kinases and modulates cell signaling, particularly the activator protein 1 (AP-1) pathway. We have shown previously that CSN1 suppresses AP-1 transcription activity and inhibits ultraviolet (UV) and serum activation of c-fos expression. Here we show that CSN1 can inhibit phosphorylation of proto-oncogene c-Jun product and repress c-Jun dependent transcription. Further, CSN1 dramatically downregulates ectopic expression of c-Jun N-terminal kinase 1 (JNK1) in cultured cells. The decline in JNK1 is not caused by excessive proteolysis or by 3' UTR-dependent mRNA instability, but by CSN1-dependent repression of one or multiple steps in transcriptional and posttranscriptional mechanisms. Thus, in contrast to CSN5/Jab1, which promotes AP-1 activity, CSN1 displays a negative effect on the AP-1 pathway. Finally, we discuss about the dynamic equilibrium of the CSN complexes in regulation of the AP-1 pathway.
3' Untranslated Regions
;
Animals
;
COP9 Signalosome Complex
;
Cell Line
;
Down-Regulation
;
Humans
;
Intracellular Signaling Peptides and Proteins
;
genetics
;
metabolism
;
Mice
;
Mitogen-Activated Protein Kinase 8
;
metabolism
;
Phosphorylation
;
Proto-Oncogene Proteins c-jun
;
antagonists & inhibitors
;
metabolism
;
Transcription Factor AP-1
;
metabolism

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