PURPOSE: In the gastric mucosa of Helicobacter pylori (H. pylori)-infected patients with gastritis or adenocarcinoma, proliferation of gastric epithelial cells is increased. Hyperproliferation is related to induction of oncogenes, such as β-catenin and c-myc. Even though transcription factors NF-κB and AP-1 are activated in H. pylori-infected cells, whether NF-κB or AP-1 regulates the expression of β-catenein or c-myc in H. pylori-infected cells has not been clarified. The present study was undertaken to investigate whether H. pylori-induced activation of NF-κB and AP-1 mediates the expression of oncogenes and hyperproliferation of gastric epithelial cells. MATERIALS AND METHODS: Gastric epithelial AGS cells were transiently transfected with mutant genes for IκBα (MAD3) and c-Jun (TAM67) or treated with a specific NF-κB inhibitor caffeic acid phenethyl ester (CAPE) or a selective AP-1 inhibitor SR-11302 to suppress activation of NF-κB or AP-1, respecively. As reference cells, the control vector pcDNA was transfected to the cells. Wild-type cells or transfected cells were cultured with or without H. pylori. RESULTS: H. pylori induced activation of NF-κB and AP-1, cell proliferation, and expression of oncogenes (β-catenein, c-myc) in AGS cells, which was inhibited by transfection of MAD3 and TAM67. Wild-type cells and the cells transfected with pcDNA showed similar activities of NF-κB and AP-1, proliferation, and oncogene expression regardless of treatment with H. pylori. Both CAPE and SR-11302 inhibited cell proliferation and expression of oncogenes in H. pylori-infected cells. CONCLUSION: H. pylori-induced activation of NF-κB and AP-1 regulates transcription of oncogenes and mediates hyperproliferation in gastric epithelial cells.
Blotting, Western ; Caffeic Acids ; Cell Line, Tumor ; Cell Proliferation ; DNA, Bacterial/analysis/genetics ; DNA-Binding Proteins/*metabolism ; Epithelial Cells/*metabolism ; Gastric Mucosa/*metabolism/pathology ; Gastritis/pathology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/metabolism/pathology/physiopathology ; Helicobacter pylori/pathogenicity/physiology ; Humans ; NF-kappa B/antagonists & inhibitors/*biosynthesis/metabolism ; Peptide Fragments ; Phenylethyl Alcohol/analogs & derivatives ; Proto-Oncogene Proteins c-jun ; Repressor Proteins ; Transcription Factor AP-1/*biosynthesis ; Transcription Factors/*metabolism ; beta Catenin/*metabolism

BACKGROUNDCathepsin L (CatL) is a cysteine protease with strong matrix degradation activity that contributes to photoaging. Mannose phosphate-independent sorting pathways mediate ultraviolet A (UVA)-induced alternate trafficking of CatL. Little is known about signaling pathways involved in the regulation of UVA-induced CatL expression and activity. This study aims to investigate whether a single UVA irradiation affects CatL expression and activity and whether mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) pathway is involved in the regulation of UVA-induced CatL expression and activity in human dermal fibroblasts (HDFs).

METHODSPrimary HDFs were exposed to UVA. Cell proliferation was determined by a cell counting kit. UVA-induced CatL production and activity were studied with quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), Western blotting, and fluorimetric assay in cell lysates collected on three consecutive days after irradiation. Time courses of UVA-activated JNK and p38MAPK signaling were examined by Western blotting. Effects of MAPK inhibitors and knockdown of Jun and Fos on UVA-induced CatL expression and activity were investigated by RT-PCR, Western blotting, and fluorimetric assay. Data were analyzed by one-way analysis of variance.

RESULTSUVA significantly increased CatL gene expression, protein abundance, and enzymatic activity for three consecutive days after irradiation (F = 83.11, 56.14, and 71.19, respectively; all P < 0.05). Further investigation demonstrated phosphorylation of JNK and p38MAPK activated by UVA. Importantly, inactivation of JNK pathway significantly decreased UVA-induced CatL expression and activity, which were not affected by p38MAPK inhibition. Moreover, knockdown of Jun and Fos significantly attenuated basal and UVA-induced CatL expression and activity.

CONCLUSIONSUVA enhances CatL production and activity in HDFs, probably by activating JNK and downstreaming AP-1. These findings provide a new possible molecular approach for antiphotoaging therapy.

Anthracenes ; pharmacology ; Cathepsin L ; metabolism ; Cells, Cultured ; Child ; Child, Preschool ; Enzyme Inhibitors ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; Fibroblasts ; cytology ; drug effects ; metabolism ; radiation effects ; Humans ; Imidazoles ; pharmacology ; MAP Kinase Signaling System ; drug effects ; radiation effects ; Oncogene Proteins v-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Pyridines ; pharmacology ; Skin ; cytology ; Ultraviolet Rays

OBJECTIVETo study the ability of aqueous extract of Hericium erinaceus mushroom in the treatment of nerve injury following peroneal nerve crush in Sprague-Dawley rats.

METHODSAqueous extract of Hericium erinaceus was given by daily oral administration following peroneal nerve crush injury in Sprague-Dawley rats. The expression of protein kinase B (Akt) and mitogen-activated protein kinase (MAPK) signaling pathways; and c-Jun and c-Fos genes were studied in dorsal root ganglia (DRG) whereas the activity of protein synthesis was assessed in peroneal nerves by immunohistochemical method.

RESULTSPeripheral nerve injury leads to changes at the axonal site of injury and remotely located DRG containing cell bodies of sensory afferent neurons. Immunofluorescence studies showed that DRG neurons ipsilateral to the crush injury in rats of treated groups expressed higher immunoreactivities for Akt, MAPK, c-Jun and c-Fos as compared with negative control group (P <0.05). The intensity of nuclear ribonucleoprotein in the distal segments of crushed nerves of treated groups was significantly higher than in the negative control group (P <0.05).

CONCLUSIONH. erinaceus is capable of promoting peripheral nerve regeneration after injury. Potential signaling pathways include Akt, MAPK, c-Jun, and c-Fos, and protein synthesis have been shown to be involved in its action.

Agaricales ; chemistry ; Animals ; Axons ; pathology ; Female ; Ganglia, Spinal ; metabolism ; Glucans ; analysis ; MAP Kinase Signaling System ; Nerve Crush ; Nerve Regeneration ; physiology ; Peripheral Nerves ; enzymology ; physiology ; Peroneal Nerve ; physiology ; Protein Biosynthesis ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Rats, Sprague-Dawley

BACKGROUNDNajanalgesin, a toxin isolated from the venom of Naja naja atra, has been shown to exert significant analgesic effects in a neuropathic pain model in rats. However, the molecular mechanism underlying this protective effect of najanalgesin is poorly understood. The present study sought to evaluate the intracellular signaling pathways that are involved in the antinociceptive effect of najanalgesin on neuropathic pain.

METHODSThe antinociceptive properties of najanalgesin were tested in hind paw withdrawal thresholds in response to mechanical stimulation. We analyzed the participation of the mitogen-activated protein kinase p38, extracellular-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK) by western blot analysis. This inhibition of JNK was confirmed by immunohistochemistry.

RESULTSThe phosphorylation levels of JNK (as well as its downstream molecule c-Jun), p38, and ERK were significantly increased after injury. Najanalgesin only inhibited JNK and c-Jun phosphorylation but had no effect on either ERK or p38. This inhibition of JNK was confirmed by immunohistochemistry, which suggested that the antinociceptive effect of najanalgesin on spinal nerve ligation-induced neuropathic pain in rats is associated with JNK activation in the spinal cord.

CONCLUSIONThe antinociceptive effect of najanalgesin functions by inhibiting the JNK in a neuropathic pain model.

Animals ; Elapid Venoms ; therapeutic use ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Immunohistochemistry ; JNK Mitogen-Activated Protein Kinases ; genetics ; metabolism ; Male ; Neuralgia ; drug therapy ; enzymology ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

Reduced radiosensitivity of lung cancer cells represents a pivotal obstacle in clinical oncology. The hypoxia-inducible factor (HIF)-1α plays a crucial role in radiosensitivity, but the detailed mechanisms remain elusive. A relationship has been suggested to exist between hypoxia and autophagy recently. In the current study, we studied the effect of hypoxia-induced autophagy on radioresistance in lung cancer cell lines. A549 and H1299 cells were cultured under normoxia or hypoxia, followed by irradiation at dosage ranging from 0 to 8 Gy. Clonogenic assay was performed to calculate surviving fraction. EGFP-LC3 plasmid was stably transfected into cells to monitor autophagic processes. Western blotting was used to evaluate the protein expression levels of HIF-1α, c-Jun, phosphorylated c-Jun, Beclin 1, LC3 and p62. The mRNA levels of Beclin 1 were detected by qRT-PCR. We found that under hypoxia, both A549 and H1299 cells were radio-resistant compared with normoxia. Hypoxia-induced elevated HIF-1α protein expression preferentially triggered autophagy, accompanied by LC3 induction, EGFP-LC3 puncta and p62 degradation. In the meantime, HIF-1α increased downstream c-Jun phosphorylation, which in turn upregulated Beclin 1 mRNA and protein expression. The upregulation of Beclin 1 expression, instead of HIF-1α, could be blocked by SP600125 (a specific inhibitor of c-Jun NH2-terminal kinase), followed by suppression of autophagy. Under hypoxia, combined treatment of irradiation and chloroquine (a potent autophagy inhibitor) significantly decreased the survival potential of lung cancer cells in vitro and in vivo. In conclusion, hypoxia-induced autophagy through evaluating Beclin1 expression may be considered as a target to reverse the radioresistance in cancer cells.
Animals ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Autophagy ; Beclin-1 ; Cell Hypoxia ; Cell Line, Tumor ; Cell Survival ; genetics ; radiation effects ; Gene Expression Regulation, Neoplastic ; radiation effects ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; Immunoblotting ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Membrane Proteins ; genetics ; metabolism ; Mice, Nude ; Microscopy, Fluorescence ; Microtubule-Associated Proteins ; genetics ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-jun ; metabolism ; Radiation Tolerance ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Transplantation, Heterologous ; Tumor Burden ; genetics

The effects of black rice anthocyanidins (BRACs) on retinal damage induced by photochemical stress are not well known. In the present study, Sprague-Dawley rats were fed AIN-93M for 1 week, after which 80 rats were randomly divided into two groups and treated with (n = 40) or without BRACs (n = 40) for 15 days, respectively. After treatment, both groups were exposed to fluorescent light (3,000 +/- 200 lux; 25degrees C), and the protective effect of dietary BRACs were evaluated afterwards. Our results showed that dietary BRACs effectively prevented retinal photochemical damage and inhibited the retinal cells apoptosis induced by fluorescent light (p < 0.05). Moreover, dietary BRACs inhibited expression of AP-1 (c-fos/c-jun subunits), up-regulated NF-kappaB (p65) expression and phosphorylation of IkappaB-alpha, and decreased Caspase-1 expression (p < 0.05). These results suggest that BRACs improve retinal damage produced by photochemical stress in rats via AP-1/NF-kappaB/Caspase-1 apoptotic mechanisms.
Animal Feed/analysis ; Animals ; Anthocyanins/administration & dosage/*pharmacology ; Antioxidants/administration & dosage/*physiology ; Blotting, Western ; Caspase 1/*genetics/metabolism ; Diet ; Dietary Supplements/analysis ; I-kappa B Proteins/genetics/metabolism ; NF-kappa B/*genetics/metabolism ; Neoplasm Proteins/genetics/metabolism ; Nucleocytoplasmic Transport Proteins/genetics/metabolism ; Oryza sativa/chemistry ; Proto-Oncogene Proteins c-fos/genetics/metabolism ; Proto-Oncogene Proteins c-jun/genetics/metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Retinal Diseases/etiology/*prevention & control ; Signal Transduction/*drug effects/radiation effects ; Transcription Factor AP-1/*genetics/metabolism

LPS stimulation of macrophages production of IFN-beta plays a key role in innate immunity defending the microbial invasion. In this study, the effect of S632A3 promoting LPS-induced IFN-beta production and the underlying mechanism were investigated, mRNA level was measured by real-time PCR, cytokine production was determined by ELISA, GSK-3beta activity was investigated by kinase assay, protein phosphorylation and expression were evaluated by Western blotting. The results revealed that S632A3 significantly augmented IFN-beta production by LPS-stimulated macrophages. S632A3 inhibition of the activation of GSK-3beta, reduced the threonine 239 phosphorylation of transcription factor c-Jun but increased the total level of c-Jun in LPS-stimulated macrophages. Moreover, small interfering RNA-mediated knockdown of c-Jun level abrogated the ability of S632A3 to augment IFN-beta. The study thus demonstrates S632A3 being a new anti-inflammation lead compound and provides a molecular mechanism by which S632A3 promoted LPS-induced IFN-beta production in macrophages through inhibiting the activation of GSK-3beta.
Animals ; Anti-Bacterial Agents ; pharmacology ; Cell Line ; Enzyme Activation ; drug effects ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Interferon-beta ; biosynthesis ; genetics ; Lipopolysaccharides ; pharmacology ; Macrophages ; cytology ; metabolism ; Mice ; Phosphorylation ; Piperidones ; pharmacology ; Proto-Oncogene Proteins c-jun ; metabolism ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

In this study, the effect of heparin-derived oligosaccharide (HDO) on bovine vascular smooth muscle cell (VSMC) proliferation and signal transduction mechanism involved were investigated. The levels of PKC-alpha protein and mRNA were determined by cell-based ELISA, RT-PCR, Western blotting and immunocytochemical methods. Meanwhile, mRNA levels of c-jun, c-myc and c-fos were assayed by RT-PCR method. The results showed that HDO inhibited newborn calf serum (NCS)-induced expression of PKC-alpha and proto-oncogenes, which may be one of the mechanisms for the inhibition of VSMC proliferation by HDO. Flow cytometry analysis indicated that HDO blocked NCS-induced cell cycle progression by arresting cells at G0/G1 phase. The results imply that HDO inhibits VSMC proliferation by moderating the gene level of PKC-alpha, eventually inhibiting proto-oncogene mRNA expression and blocking G1/S transition.
Animals ; Cattle ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; G1 Phase ; drug effects ; Heparin ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Oligosaccharides ; pharmacology ; Protein Kinase C-alpha ; genetics ; metabolism ; Proto-Oncogene Proteins c-fos ; genetics ; metabolism ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction

Paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride; PQ), an effective and widely used herbicide, was commercially introduced in 1962. It is reduced by the electron donor NADPH, and then reduced PQ transfers the electrons to molecular oxygen, resulting in the production of reactive oxygen species (ROS), which are related to cellular toxicity. However, the influence of continuous hypoxia on PQ-induced ROS production has not fully been investigated. We evaluated in vitro the protective effect of continuous hypoxia on PQ-induced cytotoxicity in the human carcinogenic alveolar basal epithelial cell line (A549 cells) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and live and dead assay, and by measuring lactate dehydrogenase (LDH) release. To elucidate the mechanism underlying this effect, we monitored the immunofluorescence of intracellular ROS and measured malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Continuous hypoxia protected the A549 cells from PQ-induced cytotoxicity. Continuous hypoxia for a period of 24 h significantly reduced intracellular ROS, decreased MDA concentration in the supernatant, and normalized SOD and GPx activities. Continuous hypoxia attenuated PQ-induced cell toxicity in A549 cells. This protective effect might be attributable to the suppression of PQ-induced ROS generation.
Apoptosis/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Flavonoids/pharmacology ; *Gene Expression Regulation, Neoplastic ; Hepatocyte Growth Factor/*pharmacology ; Humans ; Inhibitor of Apoptosis Proteins/antagonists & inhibitors/*genetics ; MAP Kinase Kinase Kinases/antagonists & inhibitors ; Neoplasm Invasiveness ; Promoter Regions, Genetic ; Protein Binding ; Proto-Oncogene Proteins c-jun/genetics/*metabolism ; Stomach Neoplasms/genetics/*metabolism/pathology ; Urokinase-Type Plasminogen Activator/*genetics

OBJECTIVETo explore the molecular mechanism of brain protection against convulsive brain damage in premature brains by observing the changes of apoptotic-regulating genes of bcl-2 and c-Jun expression in the hippocampus in Wistar rats with different ages after status convulsion (SC).

METHODSSC was induced in infant Wistar rats (IRs) and adult Wistar rats (ARs) by intraperitoneal injection of lithium-pilocarpine. The rats were sacrificed at 3 hrs, 6 hrs, 12 hrs, 1 day, 3 days and 7 days after SC (n=8). Bcl-2 and c-Jun protein and mRNA levels were measured using immunocytochemistry, RT-PCR and in situ hybridization.

RESULTSc-Jun protein levels increased significantly at 3 hrs and reached the peak at 6 hrs after SC in both IRs and ARs compared to those in the normal control group (P<0.01). c-Jun protein levels started to decrease 12 hrs after SC in both IRs and ARs. The expression of c-Jun protein in IRs returned to the basal level 1 day after SC, while remained higher in ARs than in the normal control group by 7 days after SC. The expression of c-Jun protein in ARs was much higher than that in IRs from 6 hrs to 7 days after SC (P<0.05). c-Jun mRNA level was in parallel with the protein level as mentioned in IRs and ARs after SC. There were no changes observed in both bcl-2 protein and bcl-2 mRNA levels after SC in IRs and ARs.

CONCLUSIONSSC may induce an up-regulation of proapoptotic gene c-Jun in the hippocampus after SC, with a less strong extent and shorter duration in IRs compared to that in ARs. This might be one mechanism of brain protection against convulsive brain damage in IRs. The expression of bcl-2 remains unchanged after SC and is not affected by age in both IRs and ARs.

Animals ; Apoptosis ; Gene Expression Regulation ; Hippocampus ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; analysis ; genetics ; Proto-Oncogene Proteins c-jun ; analysis ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Seizures ; metabolism