Unmethylated CpG oligodeoxynucleotides (CpG ODNs) activate immune cells to produce immune mediators. This study demonstrates that in murine macrophage RAW 264.7 cells, CpG ODN-mediated matrix metalloproteinase-9 (MMP-9) expression is regulated at transcriptional level and requires de novo protein synthesis. Inhibition of ERK and p38 MAPK, but not JNK, results in significant decrease of CpG ODN-induced MMP-9 expression. We found that endosomal maturation inhibitors, chloroquine and bafilomycin A, block CpG ODN-induced ERK and p38 MAPK activation and the subsequent MMP-9 expression. We also observed that CpG ODN induces NF-kappa B activation and NF-kappa B is a downstream target of p38 MAPK. Taken together, our data demonstrate that CpG ODN triggers MMP-9 expression via TLR-9 dependent ERK and p38 MAPK activation followed by NF-kappa B activation.
Animals ; Cell Line ; Enzyme Activation/drug effects ; Enzyme Induction/drug effects ; Matrix Metalloproteinase 9/*biosynthesis ; Mice ; Mitogen-Activated Protein Kinase 1/antagonists & inhibitors/metabolism ; Mitogen-Activated Protein Kinase 3/antagonists & inhibitors/metabolism ; Mitogen-Activated Protein Kinases/*metabolism ; NF-kappa B/*metabolism ; Oligodeoxyribonucleotides/*pharmacology ; Signal Transduction/drug effects ; Toll-Like Receptor 9/antagonists & inhibitors/*metabolism ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism

OBJECTIVETo investigate the effects of mitogen activated protein kinase (MAPK) signal transduction pathways on heat shock protein 70 (HSP70) gene expression in endothelial cells exposed to benzo(a)pryene (BaP).

METHODSPorcine aortic endothelial cells were pre-treated or by PD98059 (10 micro mol/L) or SB203580 (20 micro mol/L) for 1 hour, then treated with different concentrations of BaP (0, 0.1, 0.5, 1.0, 5.0 and 10.0 micro mol/L) for 24 hours respectively;Expression levels of three phosphorylated MAPKs [extracellular signal regulated protein kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38] and HSP70 were determined by Western-blot.

RESULTSThe three phosphorylated MAPKs expressional levels especially p-ERK1 had different extents of changes with dose-response relationship under BaP exposure. BaP inhibited the expression of HSP70, which significantly decreased in medium and high dose group (>or= 1.0 micro mol/L) but did not decrease in control group (P < 0.05). Although the inhibitor of ERK (PD98059) could partly weaken the inhibited effects of BaP on HSP70 expression, HSP70 expression levels of endothelial cells pre-treated with PD98059 were still significantly lower than that of control cells (P < 0.05).

CONCLUSIONERK1 pathway might play some roles in HSP70 gene expression in endothelial cells exposed to BaP, and other unknown signal pathways might also have some effects on this process.

Animals ; Benzo(a)pyrene ; toxicity ; Blotting, Western ; Dose-Response Relationship, Drug ; Endothelial Cells ; drug effects ; metabolism ; Enzyme Inhibitors ; pharmacology ; Flavonoids ; pharmacology ; HSP70 Heat-Shock Proteins ; analysis ; Imidazoles ; pharmacology ; JNK Mitogen-Activated Protein Kinases ; MAP Kinase Kinase 4 ; Mitogen-Activated Protein Kinase Kinases ; analysis ; Mitogen-Activated Protein Kinases ; analysis ; antagonists & inhibitors ; Pyridines ; pharmacology ; Signal Transduction ; physiology ; Swine ; p38 Mitogen-Activated Protein Kinases

Currently, about 300 million people worldwide are affected by asthma. Most of these sufferers inhale immunosuppressants (ie corticosteroids) and beta-adrenergic receptor agonists for their asthma treatment. However, about 5%-10% of patients of asthma have poor response to such treatment. Investigation of kinase signaling pathway and nuclear transcription factor as a target molecule in the treatment of allergic asthma has been the concern of scholars home and abroad. This paper reviewed inhibitors of kinase signaling pathway and nuclear transcription factors for the treatment of asthma.
Animals ; Asthma ; drug therapy ; enzymology ; Humans ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; Phosphatidylinositol 3-Kinase ; antagonists & inhibitors ; Protein Kinase Inhibitors ; therapeutic use ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Signal Transduction ; Transcription Factors ; antagonists & inhibitors

OBJECTIVETo investigate the effect of SP600125, a specific c-jun N-terminal protein kinase (JNK) inhibitor, on Staphylococcus aureus (S. aureus)-induced U937 cell death and the underlying mechanism.

METHODSThe human monocytic U937 cells were treated with S. aureus at different time with or without SP600125. Cell apoptosis was analyzed by flow cytometry. JNK, Bax, and caspase-3 activities were detected by Western blotting.

RESULTSS. aureus induced apoptosis in cultured U937 cells in a time-dependent manner. Expression of Bax and phospho-JNK significantly increased in S. aureus-treated U937 cells, and the level of activated caspase-3 also increased in a time-dependent manner. Inhibition of JNK with SP600125 significantly inhibited S. aureus-induced apoptosis in U937 cells.

CONCLUSIONSS. aureus can induce apoptosis in U937 cells by phosphorylation of JNK and activation of Bax and caspase-3. SP600125 protects U937 cells from apoptosis induced by S. aureus via inhibiting the activity of JNK.

Anthracenes ; pharmacology ; Apoptosis ; physiology ; Caspase 3 ; metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Macrophages ; cytology ; metabolism ; microbiology ; Mitogen-Activated Protein Kinase 8 ; antagonists & inhibitors ; metabolism ; Mitogen-Activated Protein Kinase 9 ; antagonists & inhibitors ; metabolism ; Phosphorylation ; drug effects ; Protein Kinase Inhibitors ; pharmacology ; Signal Transduction ; physiology ; Staphylococcus aureus ; physiology ; U937 Cells ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo study the changes of telomerase activity and protein expression of phosphorylated (activated) extracellular regulated protein kinases (ERK1 and ERK2) in the course of inhibiting hepatocarcinomatous cell proliferation and inducing cell apoptosis by three kinds of chemotherapy drugs: Harringtonine (HRT), Vincristine (VCR), and Etoposide (Vp16). To discuss the regulative function to hepatocarcinomatous cell apoptosis and interrelation of telomerase and ERK.

METHODSCytotoxicity assay, flow cytometry analysis, telomerase repeat amplification protocol assay (TRAP), bioluminescence analysis, and western blot were used in this experiment.

RESULTSHRT, VCR, and Vp16 could inhibit cell proliferation (0.28% 0.08%, 0.25% 0.16%, 0.24% 0.11%), induce apoptosis (21.12%, 28.83%, 12.30%), inhibit telomerase activity, and down-regulate the protein expression of phosphorylated ERK.

CONCLUSIONSIt might be through ERK signal transduction pathways that chemotherapy drugs down-regulate telomerase activity and induce apoptosis.

Apoptosis ; Carcinoma, Hepatocellular ; drug therapy ; enzymology ; pathology ; Etoposide ; pharmacology ; Harringtonines ; pharmacology ; Humans ; Liver Neoplasms ; drug therapy ; enzymology ; pathology ; Mitogen-Activated Protein Kinase 1 ; antagonists & inhibitors ; physiology ; Mitogen-Activated Protein Kinase 3 ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; physiology ; Signal Transduction ; Telomerase ; physiology ; Tumor Cells, Cultured ; Vincristine ; pharmacology

NMDA-induced excitotoxicity cause severe neuronal damage including apoptosis and necrosis. The present study was aimed to evaluate the proportion of NMDA-induced apoptosis of rat cortical neurons and discover signal transduction mechanism. Caspase inhibitor and lactate dehydrogenase (LDH) assay were used to study the NMDA-induced apoptosis. To explore the involved signal pathways, the primary culture of rat cortical neurons were pretreated by the inhibitors of three MAPK pathways, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. With 2 h of NMDA treatment, cellular apoptosis was measured by caspase-3 activity, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) and Annexin V staining. The results showed that: (1) Caspase-dependent apoptosis accounted for 22.49% in NMDA-induced neuronal death; (2) Pretreatment with p38 MAPK inhibitor SB203580 (10 μmol/L) significantly decreased NMDA-mediated caspase-3 activity by 30.43% (P < 0.05). However, ERK inhibitor PD98059 (20 μmol/L) or JNK inhibitor SP600125 (20 μmol/L) did not influence caspase-3 activity; (3) Pretreatment with SB203580 significantly reduced the number of NMDA-induced TUNEL-positive cells by 33.10% (P < 0.05). PD98059 (20 μmol/L) or SP600125 (20 μmol/L) did not show obvious effect; (4) Pretreatment with SB203580 (10 μmol/L) significantly reduced the number of NMDA-induced early apoptotic neurons by 55.56% (P < 0.05). Also, SP600125 (20 μmol/L) significantly decreased the amount of late apoptotic/dead cells by 67.59% (P < 0.05). There was no effect of PD98059 (20 μmol/L). These results indicate that: (1) NMDA induces neuronal apoptosis besides necrosis; (2) p38 MAPK, but not JNK and ERK, is involved in NMDA-induced neuronal apoptosis, and inhibition of the apoptotic signaling pathway contributes to neuroprotection; (3) JNK activation might contribute to NMDA-induced neuronal necrosis rather than apoptosis.
Animals ; Anthracenes ; pharmacology ; Apoptosis ; Caspase 3 ; metabolism ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; Imidazoles ; pharmacology ; JNK Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; MAP Kinase Signaling System ; N-Methylaspartate ; pharmacology ; Neurons ; cytology ; Primary Cell Culture ; Pyridines ; pharmacology ; Rats ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors

OBJECTIVETo investigate the potential molecular mechanism underlying down-regulation of albumin expression induced by lipopolysaccharide (LPS) in rat hepatocytes.

METHODSThe albumin mRNA expression and albumin protein levels in the supernatant were observed at 0, 2, 8, 12 and 24 hours after 1 micro g/ml LPS treatment. The albumin mRNA expression was determined by RT-PCR, and albumin protein levels were assayed with EIA in the supernatant of hepatocytes pretreated with specific inhibitors of extracellular signal-regulated kinase (PD98059) and p38 kinase (SB203580).

RESULTSThe albumin mRNA expression was reduced to 70% of baseline value, meanwhile, the albumin protein concentration in the supernatant was reduced by 50% compared with the controls after 24 hours of LPS treatment. Pretreatment with PD98059 and SB203580 did significantly inhibit the reduction of albumin by LPS at the given dose.

CONCLUSIONThe results indicate that LPS can induce the reduction of albumin synthesis by down-regulation of albumin mRNA expression at transcription level, and the process may be related to the signal transducation of extracellular signal-regulated kinase and p38 kinase.

Albumins ; genetics ; metabolism ; Animals ; Calcium-Calmodulin-Dependent Protein Kinases ; antagonists & inhibitors ; Dose-Response Relationship, Drug ; Down-Regulation ; Enzyme Inhibitors ; pharmacology ; Enzyme-Linked Immunosorbent Assay ; Flavonoids ; pharmacology ; Hepatocytes ; drug effects ; metabolism ; Imidazoles ; pharmacology ; Lipopolysaccharides ; toxicity ; Male ; Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; Pyridines ; pharmacology ; RNA, Messenger ; genetics ; metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors ; p38 Mitogen-Activated Protein Kinases

PURPOSE: Based on the close relationship between histamine and interleukin 6 (IL-6), we hypothesized that histamine may regulate the production of cytokines, such as IL-6, during allergic inflammation. Here, we examined the role of histamine in IL-6 production and histamine receptor activity in nasal fibroblasts, along with the mechanisms underlying these effects. METHODS: Experiments were performed using nasal fibroblasts from 8 normal patients. RT-PCR was used to identify the major histamine receptors expressed in nasal fibroblasts. Fibroblasts were then treated with histamine with or without histamine-receptor antagonists, and monitored for IL-6 production using an ELISA. Four potential downstream signaling molecules, p38, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and NF-kappaB, were evaluated by Western blot, and a luciferase reporter assay. RESULTS: Elevated expression was seen for all histamine receptors, with IL-6 protein levels increasing significantly following histamine stimulation. Among the histamine-receptor specific antagonists, only the H1R antagonist significantly decreased IL-6 production in histamine-stimulated nasal fibroblasts. Histamine increased the expression level of phosphorylated p38 (pp38), pERK, and pJNK, as well as NF-kappaB induction. The H1R antagonist actively suppressed pp38 and NF-kappaB expression in histamine-induced nasal fibroblasts, but not pERK and pJNK. The p38 inhibitor strongly attenuated IL-6 production in histamine-stimulated nasal fibroblasts. CONCLUSIONS: The data presented here suggest that antihistamines may be involved in the regulation of cytokines, such as IL-6, due to the role of histamine as an inflammatory mediator in nasal fibroblasts.
Blotting, Western ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Fibroblasts* ; Histamine Antagonists ; Histamine* ; Humans ; Inflammation ; Interleukin-6* ; JNK Mitogen-Activated Protein Kinases ; Luciferases ; NF-kappa B* ; Nose ; Phosphotransferases ; Receptors, Histamine

OBJECTIVETo study the effect of p38 on the cycloheximide (CHX)-induced HL-60 cell death through mitochondria pathway.

METHODSInhibition of p38 pathway was by SB203580 (SB). Four groups were set up: control, SB only, CHX only and SB + CHX. Sub-diploid cell ratio was detected by PI staining flow cytometry at 6, 9, 12, 18, 24 h time points, and apoptotic cell ratio by Annexin V-FITC/PI double staining flow cytometry at 6 h and 18 h time points. High J-aggregate cells were evaluated by the J-aggregate contents, measurement of the J-aggregate (FL2) and J-monomer (FL1) by JC-1 flow cytometry, calculation of the delta psi m by FL2/FL1 and analysis of the delta psi m changes at 18 h time points.

RESULTSThe sub-diploid cell ratio in CHX group was significantly higher than that in control group at 6 h time point, and the ratio in SB + CHX group was significantly higher than that in CHX group at 9 h time point. At 18 h time point the apoptotic cell ratios in both CHX and SB + CHX groups were significantly higher than those in control group (P < 0.01). There was no significant difference of apoptotic cell ratio between CHX group and SB + CHX group (P > 0.05). At 18 h time point the necrotic cell ratios in both CHX and SB + CHX groups were significantly higher than that in control group (P < 0.01); and that in SB + CHX group was significantly higher than that in CHX group (P < 0.01). The high J-aggregate cell ratios in CHX and SB + CHX groups were significantly lower than that in control group (P < 0.05), and that was signficantly lower in SB + CHX group than in CHX group (P < 0.01). For the FL2/FL1 value (delta psi m) CHX group (0.17 +/- 0.01) and SB + CHX group (0.05 +/- 0.003) were significantly higher than control group (0.38 +/- 0.02) (P < 0.01), and SB + CHX group was significantly lower than CHX group (P < 0.01).

CONCLUSIONCHX can induce HL-60 cell apoptosis and the cell mitochondria depolarization, and the latter was intensified by inhibition of the p38 pathway. p38 pathway may related to the cell necrosis in the cycloheximide-induced HL-60 cell apoptosis model. s

Apoptosis ; drug effects ; Cycloheximide ; pharmacology ; HL-60 Cells ; Humans ; Membrane Potentials ; Mitochondria ; physiology ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors ; metabolism

We stimulated preadipocyte of mice with calcium acetate, p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580, the paralysors and excitomotors of calcium channel. Then we detected expression level of preadipocyte differentiation's marker genes and calcium signal related acceptor genes by real-time PCR, and determined intracellular free Ca2+ concentration ([Ca2+]i]) with Fura-2/AM, intracellular lipid accumulation by oil red O staining. Our aim was to investigate the potential mechanism between calcium signal and preadipocyte differentiation. The results indicated that the paralysors and excitomotors of calcium channel changed the expression level of lipoprotein lipase (LPL), peroxisome proliferators-activated receptor gamma (PPARgamma), fatty acid synthetase (FAS), and the lipid accumulation, markedly. Compared with exocellular Ca2+'s decrease, inhibited intracellular Ca2+'s liberation can promoted preadipocyte differentiation (P < 0.01), and compared with intracellular Ca2+'s increase, promoted exocellular Ca2+'s ingest inhibited preadipocyte differentiation (P < 0.01). SB203580 degraded [Ca2+]i, promoted differentiation marker genes' expression and lipid accumulation in preadipocyte (P < 0.01). But calcium signal didn't have effects to vitamin D receptor (VDR) and extracellular Ca2+-sensing receptor (CaSR)'s expression. It indicated that calcium signal may effect preadipocyte different and lipid accumulation by p38 MAPK pathway.
Adipocytes ; cytology ; Animals ; Calcium ; metabolism ; Calcium Signaling ; drug effects ; Cell Differentiation ; physiology ; Cells, Cultured ; Imidazoles ; pharmacology ; Lipids ; biosynthesis ; Mice ; Pyridines ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; antagonists & inhibitors