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

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

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

OBJECTIVETo cultivate human umbilical vein endothelial cells (HUVECs) in the serum of overfatigue rats with the intervention of Tongxinluo superfine powder (TXLSP). By examining the variation of the activity of JNK/c-Jun/HO-1 pathway, the possible mechanisms of vascular endothelial dysfunction under overfatigue conditions and the intervening effect of TXLSP were explored.

METHODSThe HUVECs were randomly divided into the normal control group, the model group, the SP600125 (a specific antagonist of JNK) group, the TXLSP group and the TXLSP + SP600125 group. The content of carboyhemoglobin (COHb) and the leak rate of lactic dehydrogenase (LDH) in different groups were measured. The mRNA and protein expression of JNK, c-Jun, HO-1 and the phosphorylation level of c-Jun (P-c-Jun) were detected using Western blot and PCR methods.

RESULTSCompared with the normal control group, the COHb level in supernatant was increased significantly in the model group, and the expression of HO-1, JNK, c-Jun mRNA and corresponding proteins and P-c-Jun were also increased remarkably. The increases in these parameters were significantly decreased by SP600125. TXLSP showed remarkable up-regulation on the expression of JNK, c-Jun, P-c-Jun and HO-1 mRNA and their protein expression. Compared with the SP600125 group, the expressions of JNK, c-Jun, P-c-Jun and HO-1 mRNA and its protein in the TXLSP+SP600125 group were significantly increased at different time points (P<0.05, P<0.01).

CONCLUSIONSThe vascular endothelial dysfunction under overfatigue conditions is related to the activity of the JNK/c-Jun/HO-1 pathway. One of the mechanisms of TXLSP in improving the vascular endothelial function is to adjust the activity of the JNK/c-Jun/HO-1 pathway at gene and protein levels.

Animals ; Blood Proteins ; pharmacology ; Cells, Cultured ; Cytoprotection ; drug effects ; genetics ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Endothelial Cells ; drug effects ; metabolism ; Fatigue ; blood ; metabolism ; Heme Oxygenase (Decyclizing) ; genetics ; metabolism ; physiology ; Humans ; JNK Mitogen-Activated Protein Kinases ; genetics ; metabolism ; physiology ; Male ; Particle Size ; Powders ; administration & dosage ; pharmacology ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; physiology ; Rats ; Rats, Wistar ; Serum ; metabolism ; physiology ; Signal Transduction ; drug effects ; genetics ; physiology ; Umbilical Veins ; cytology ; drug effects ; metabolism

Expression of protein kinase C-delta (PKC delta) is up-regulated by apoptosis-inducing stimuli. However, very little is known about the signaling pathways that control PKC delta gene transcription. In the present study, we demonstrate that JNK stimulates PKC delta gene expression via c-Jun and ATF2 in response to the anticancer agent doxorubicin (DXR) in mouse lymphocytic leukemia L1210 cells. Luciferase reporter assays showed that DXR-induced activation of the PKC delta promoter was enhanced by ectopic expression of JNK1, c-Jun, or ATF2, whereas it was strongly reduced by expression of dominant negative JNK1 or by treatment with the JNK inhibitor SP600125. Furthermore, point mutations in the core sequence of the c-Jun/ATF2 binding site suppressed DXR-induced activation of the PKC delta promoter. Our results suggest an additional role for a JNK signaling cascade in DXR-induced PKC delta gene expression.
Activating Transcription Factor 2/*physiology ; Animals ; Anthracenes/pharmacology ; Antibiotics, Antineoplastic/*pharmacology ; Apoptosis ; Cell Line, Tumor ; Doxorubicin/*pharmacology ; Mice ; Mitogen-Activated Protein Kinase 8/*physiology ; Mutation ; Promoter Regions, Genetic ; Protein Kinase C-delta/genetics/*metabolism ; Proto-Oncogene Proteins c-jun/antagonists & inhibitors/*physiology ; Signal Transduction/physiology ; Transcription, Genetic

Apoptosis ; Cell Cycle ; Cell Differentiation ; Cell Proliferation ; Humans ; Neoplastic Processes ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; physiology

BACKGROUNDSolar ultraviolet (UV) irradiation induces the production of matrix metalloproteinases (MMPs) by activating cellular signalling transduction pathways. MMPs are responsible for the degradation and/or inhibition of synthesis of collagenous extracellular matrix in connective tissues. We mimicked the action of environmental ultraviolet on skin and investigated the effects of UVB-irradiated human keratinocytes HaCaT and IL-1alpha on mitogen activated protein (MAP) kinase activation, c-Jun and c-Fos (AP-1 is composed of Jun and Fos proteins) mRNA expression and MMP-1 production in UVA-irradiated dermal fibroblasts.

METHODSFollowing UVA irradiation, the culture medium of fibroblasts was replaced by culture medium from UVB-irradiated HaCaT, or replaced by the complete culture medium with interleukin (IL)-1alpha. MAP kinase activity expression in fibroblasts was detected by Western blot. c-Jun and c-Fos mRNA expressions were determined by reverse transcriptional polymerase chain reaction (RT-PCR); MMP-1 production in culture medium was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTSCulture medium from UVB-irradiated keratinocytes increased MAP kinase activity and c-Jun mRNA expression in UVA-irradiated fibroblasts. IL-1alpha increased MAP kinase activity and c-Jun mRNA expression, IL-1alpha also increased c-Fos mRNA expression. Both culture media from UVB-irradiated human keratinocytes and externally applied IL-1alpha increased MMP-1 production in UVA-irradiated fibroblasts.

CONCLUSIONSUVB-irradiated keratinocytes and IL-1alpha indirectly promote MMP-1 production in UVA-irradiated fibroblasts by increasing MAP kinase/AP-1 activity. IL-1 may play an important role in the paracrine activation and dermal collagen excessive degradation leading to skin photoaging.

Cell Line ; Enzyme Activation ; Fibroblasts ; enzymology ; radiation effects ; Humans ; Interleukin-1 ; pharmacology ; Keratinocytes ; physiology ; radiation effects ; Matrix Metalloproteinase 1 ; biosynthesis ; Mitogen-Activated Protein Kinases ; metabolism ; Proto-Oncogene Proteins c-fos ; genetics ; Proto-Oncogene Proteins c-jun ; genetics ; RNA, Messenger ; analysis ; Skin ; radiation effects ; Skin Aging ; Transcription Factor AP-1 ; metabolism ; Ultraviolet Rays

AIMTo further uncover the possible mechanism of quercetin-mediated inhibitory effect on prostate cancer cells.

METHODSThe cell extracts treated with quercetin or without treatment were used for checking protein expression levels of c-Jun and cAMP response element binding protein (CREB)-binding protein (CBP) by Western blotting assay. Regulatory effects of c-Jun and CBP on the function of androgen receptor (AR) were examined by cotransfection experiment. Finally, a physical interaction of c-Jun and the AR was investigated by coimmunoprecipitation.

RESULTSQuercetin dramatically induced the protein expression of c-Jun which in turn inhibited the AR function. Meanwhile, quercetin had no detectable effect on CBP expression, and the results of transient transfection demonstrated that the ectopic CBP stimulated the transcriptional activity of AR, whereas CBP-mediated stimulation could be attenuated by quercetin. Furthermore, physical interaction of c-Jun and the AR was confirmed by coimmunoprecipitation result.

CONCLUSIONOverexpression of c-Jun induced by quercetin had inhibitory effect on the function of AR protein, and increased CBP expression did not reverse the inhibition by quercetin. Together, quercetin-mediated inhibition on the AR function might be not by competition with limited amount of CBP in the cell, but through a direct association of c-Jun and the AR.

Antineoplastic Agents, Phytogenic ; pharmacology ; CREB-Binding Protein ; genetics ; metabolism ; physiology ; Cell Line, Tumor ; Humans ; Immunoprecipitation ; Male ; Prostatic Neoplasms ; metabolism ; pathology ; Protein Binding ; drug effects ; Proto-Oncogene Proteins c-jun ; genetics ; metabolism ; physiology ; Quercetin ; pharmacology ; Receptors, Androgen ; genetics ; physiology ; Transfection

In order to investigate the mechanism of mechanical stress-mediated arterial remodeling, we studied the pressure-induced expression of immediate-early response gene product c-Jun in common carotid arteries in rats. The common carotid arteries were perfused with both high pressure (160 mmHg) and normal pressure (80 mmHg) for 0.5, 1, 3 and 6 hours. Expression of immediate-early response gene product c-Jun in the arteries was examined by immunohistochemistry and computer image processing. c-Jun was weakly expressed at 1 h, then increased at 3 h and 6 h after exposure of the arteries to normal pressure. Positive immunohistochemical product of c-Jun appeared in the arteries at 0.5 h after the onset of high pressure, then it increased markedly till 6 h. There was significant difference between the two groups. These results indicate that expression of c-Jun of the arteries can be induced by pressure, which may play an important role in mechanical stress-mediated arterial remodeling.
Animals ; Biomechanical Phenomena ; Carotid Artery, Common ; cytology ; metabolism ; physiology ; Genes, Immediate-Early ; Male ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Pressure ; Proto-Oncogene Proteins c-jun ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley ; Stress, Mechanical

The stress environment regulates the factors of growth, resorption and remolding in bone tissue. Mechanical stimulation at cell physical level affects the physiological activity of osteoblasts, including proliferation, ALP activity and osteocalcin production. Mechanotransduction is a procedure which transduces the biophysical force into biochemical responses. It is also the basis of many physiological functions. The early response genes (c-fos, c-jun), the second message systems (Ca2+, NO, cAMP) and the mechano-sensitive cation channel are involved in the mechanotransduction course when osteoblasts respond to the mechanical stimulation.
Biomechanical Phenomena ; Calcium ; physiology ; Humans ; Mechanotransduction, Cellular ; Osteoblasts ; physiology ; Osteocalcin ; biosynthesis ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-jun ; biosynthesis ; genetics ; Signal Transduction ; Stress, Mechanical