OBJECTIVETo study influence of lanthanum chloride (LaCl(3)) on the expression of immediate early genes (IEGs) including c-jun, early growth response gene 1 (Egr1) and activity-regulated cytoskeletal gene (Arc) in the hippocampus of rats, and discuss the mechanism of LaCl(3) undermining learning and memory capability.

METHODSForty female Wistar adult rats were divided into control group, low LaCl(3)-contaminated group (0.25%), medium LaCl(3)-contaminated group (0.50%), and high LaCl(3)-contaminated group (1.00%) by randomized design. Each group had ten female rats along with five male rats and mated by the ratio of 2:1. The amounts of pups in the above four groups were 80, 83, 78 and 75 separately. The pups in respective group were La-dyed by lactation, and then the pups in LaCl(3)-contaminated groups drank 0.25%, 0.50% and 1.00% LaCl(3) separately for one month. Learning and memory capability of pups were measured in jumping stairs experiment. Hippocampal lanthanum content was determined by inductively coupled plasma mass spectrometry (ICP-MS). Hippocampal c-jun, Egr1 and Arc mRNA expression was detected by RT-PCR, and corresponding protein expression was measured by Western blotting method.

RESULTSIn the jumping stairs experiment, pups in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups respectively made (1.75 ± 0.71), (2.38 ± 0.92) and (3.00 ± 0.76) mistakes; significantly higher than control group (1.25 ± 0.46) (q values were 4.386, 6.793, P < 0.05). However, the incubation period of 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups were (174.13 ± 33.72), (139.25 ± 45.83) and (75.50 ± 18.56) respectively, which were all significantly lower than that of control group (206.75 ± 20.47) (q values were 2.958, 6.121, 11.902, P < 0.05). Hippocampal c-jun mRNA expression were (0.89 ± 0.08), (0.77 ± 0.12), (0.58 ± 0.14) and (0.29 ± 0.10); while the c-jun protein expression were (0.72 ± 0.13), (0.64 ± 0.11), (0.43 ± 0.11) and (0.31 ± 0.14), and the Egr1 mRNA expression were (0.78 ± 0.09), (0.61 ± 0.13), (0.53 ± 0.10) and (0.22 ± 0.08), Egr1 protein expression were (0.65 ± 0.18), (0.40 ± 0.15), (0.32 ± 0.13) and (0.14 ± 0.09) in 0.25%, 0.50% and 1.00% LaCl(3)-contaminated groups; and all of which presented a dose-effect relationship that the correlation coefficients of these parameters with dose were -0.900 (t = 11.309, P = 0.000), -0.969 (t = 7.058, P = 0.000), -0.898 (t = 11.179, P = 0.000) and -0.962 (t = 6.739, P = 0.000).

CONCLUSIONLaCl(3) undermines the learning and memory capability of rats, which is possibly related to lower expression of c-jun and Egr1 gene and protein induced by lanthanum in hippocampus.

Animals ; Early Growth Response Protein 1 ; metabolism ; Female ; Gene Expression ; Genes, Immediate-Early ; drug effects ; genetics ; Hippocampus ; drug effects ; metabolism ; Lanthanum ; pharmacology ; Learning ; drug effects ; Male ; Memory ; drug effects ; Proto-Oncogene Proteins c-jun ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo investigate the changes of proto-oncogene c-fos, c-jun mRNA expression in angiotensin II (Ang II)-induced hypertrophy and effects of tanshinone II A (Tan) in the primary culture of neonatal rat cardiomyocytes.

METHODTwelve neonatal Wistar rats aged one day old of clean grade and both sexes were selected to isolate and culture cardiomyocytes. The cardiomyocytes were divided into: normal control group, Ang II (10(-6) mol x L(-1)) group, Ang II (10(-6) mol x L(-1)) +Tan (10(-8) g x L(-1)) group, Ang II (10(-6) mol x L(-1)) + valsartan (10(-6) mol x L(-1)) group, Tan (10(-8) g x L(-1)) group, valsartan (10(-6) mol x L(-1)) group. The cardiomyocyte size was determined by phase contrast microscope, the rate of protein synthesis in cardiomyocytes was measured by 3H-leucine incorporation. The c-fos, c-jun mRNA expression of cardiomyocytes were assessed using reverse transcription polymerase chain reaction (RT-PCR).

RESULTAng II was added to the culture medium and 30 min later, the c-fos, c-jun mRNA expression of cardiomyocytes increased significantly (P < 0. 01). After Ang II took effect for 24 h, the rate of protein synthesis in Ang II group increased more prominently than that in normal control group (P < 0.01). After Ang II took effect for 7 days, the size of cardiomyocyte in Ang II group increased obviously (P < 0. 05). If tanshinone II or valsartan was added to the culture medium before Ang II, both of them could inhibit the increase of c-fos, c-jun mRNA expression (P < 0.01), cardiomyocyte protein synthesis rate (P < 0.01), and cardiomyocyte size (P < 0.05) induced by Ang II.

CONCLUSIONTanshinone II could ameliorate Ang II-induced cardiomyocytes hypertrophy by inhabiting c-fos, c-jun mRNA expression.

Angiotensin II ; biosynthesis ; pharmacology ; Animals ; Cardiomegaly ; chemically induced ; metabolism ; pathology ; Diterpenes, Abietane ; Gene Expression Regulation ; drug effects ; Genes, fos ; genetics ; Genes, jun ; genetics ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Phenanthrenes ; pharmacology ; Proto-Oncogene Proteins c-fos ; genetics ; Proto-Oncogene Proteins c-jun ; genetics ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Tetrazoles ; pharmacology ; Valine ; analogs & derivatives ; pharmacology ; Valsartan

OBJECTIVETo analyze the upstream region of radiation-induced junB gene.

METHODSFour plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/beta-actin measured by quantitative Northern blot hybridization.

RESULTSCAT mRNA expression containing 900 bp and 1560 bp junB promoter remarkably and rapidly increased, and reached its peak 30 min after 2 Gy X-ray irradiation.

CONCLUSIONS590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.

Actins ; analysis ; metabolism ; Animals ; Blotting, Northern ; Cells, Cultured ; Chloramphenicol O-Acetyltransferase ; genetics ; Gene Expression Regulation ; radiation effects ; Genes, Reporter ; Genes, jun ; genetics ; radiation effects ; In Situ Hybridization ; Mice ; Mice, Inbred BALB C ; Plasmids ; analysis ; genetics ; RNA ; isolation & purification ; metabolism ; RNA, Messenger ; analysis ; metabolism ; Time Factors ; X-Rays

OBJECTIVETo study the effects of selenium on DNA damage, apoptosis and c-myc, c-fos, and c-jun expression in rat hepatocytes.

METHODSSodium selenite at the doses of 5, 10, and 20 micromol/kg was given to rats by i.p. and there were 5 male SD rats in each group. Hepatocellular DNA damage was detected by single cell gel electrophoresis (or comet assay). Hepatocellular apoptosis was determined by TUNEL (TdT-mediated dUTP nick end labelling) and flow cytometry. C-myc, c-fos, and c-jun expression in rat hepatocytes were assayed by Northern dot hybridization. C-myc, c-fos, and c-jun protein were detected by immunohistochemical method.

RESULTSAt the doses of 5, 10, and 20 micromol/kg, DNA damage was induced by sodium selenite in rat hepatocytes and the rates of comet cells were 34.40%, 74.80%, and 91.40% respectively. Results also showed an obvious dose-response relationship between the rates of comet cells and the doses of sodium selenite (r=0.9501, P<0.01). Sodium selenite at the doses of 5, 10, and 20 micromol/kg caused c-myc, c-fos, and c-jun overexpression obviously. The positive brown-yellow signal for proteins of c-myc, c-fos, and c-jun was mainly located in the cytoplasm of hepatocytes with immunohistochemical method. TUNEL-positive cells were detected in selenium-treated rat livers. Apoptotic rates (%) of selenium-treated liver cells at the doses of 5, 10, and 20 micromol/kg were (3.72 +/- 1.76), (5.82 +/- 1.42), and (11.76 +/- 1.87) respectively, being much higher than those in the control. Besides an obvious dose-response relationship between apoptotic rates and the doses of sodium selenite (r=0.9897, P<0.01), these results displayed a close relationship between DNA damage rates and apoptotic rates, and the relative coefficient was 0.9021, P<0.01.

CONCLUSIONSelenium at 5-20 micromol/kg can induce DNA damage, apoptosis, and overexpression of c-myc, c-fos, and c-jun in rat hepatocytes.

Animals ; Apoptosis ; drug effects ; Blotting, Northern ; Comet Assay ; DNA Damage ; Dose-Response Relationship, Drug ; Genes, fos ; drug effects ; genetics ; Genes, jun ; drug effects ; genetics ; Genes, myc ; drug effects ; genetics ; Hepatocytes ; drug effects ; pathology ; Male ; Nucleic Acid Hybridization ; Rats ; Rats, Sprague-Dawley ; Selenium ; pharmacology ; Sodium Selenite ; pharmacology

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

OBJECTIVEMercury (Hg), as one of the priority pollutants and also a hot topic of frontier environmental research in many countries, has been paid higher attention in the world since the middle of the last century. Guizhou Province (at N24 degrees 30'-29 degrees 13', E103 degrees 1'-109 degrees 30', 1 100 m above the sea level, with subtropical humid climate) in southwest China is an important mercury production center. It has been found that the mercury content in most media of aquatics, soil, atmosphere and in biomass of corns, plants and animals, is higher than the national standard. The present study aims to explore the influence of mercury pollution on the health of local citizens.

METHODSThe effect of rice from two mercury polluted experimental plots of Guizhou Province on the expression of c-jun mRNA in rat brain and c-jun protein in cortex, hippocampus and ependyma was observed using reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemical methods.

RESULTSThe results showed that the mercury polluted rice induced expression of c-jun mRNA and its protein significantly. Selenium can reduce Hg uptake, an antagonism between selenium and mercury on the expression of c-jun mRNA and c-jun protein.

CONCLUSIONc-jun participates in the toxicity process of brain injury by mercury polluted rice, the expression of c-jun mRNA in brain, and c-jun protein in rat cortex and hippocampus can predict neurotoxicity of mercury polluted rice. People should be advised to be cautious in eating any kind of Hg-polluted foods. To reveal the relationship between c-jun induction and apoptosis, further examinations are required.

Animals ; Atmosphere ; Base Sequence ; Biomass ; Brain ; drug effects ; metabolism ; China ; Food Contamination ; Genes, jun ; genetics ; Immunohistochemistry ; Mercury ; analysis ; toxicity ; Oryza ; chemistry ; RNA, Messenger ; genetics ; metabolism ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Soil Pollutants ; analysis ; toxicity ; Time Factors

OBJECTIVEIt was reported previously that genistein could inhibit proliferation of human ovarian carcinoma cell line SKOV(3), but mechanism was not clear. There is a close relationship between EGFR mediated signal transduction pathway and the development of ovarian tumor. This study aimed to investigate the effects of genistein on the EGFR mediated signal transduction pathway and to clarify its mechanisms of proliferation inhibition on human ovarian carcinoma cell line SKOV(3) and its xenograft in nude mice.

METHODSThe expression of c-erbB-2 protein was determined using immunocytochemistry. The expressions of c-jun and c-fos protein were determined using Western blotting. The expression of c-erbB-2, c-raf-1, c-jun and c-fos mRNA were tested by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSThe expression of c-erbB-2, c-raf-1 and its downstream gene c-jun and c-fos were decreased at mRNA level in the 20 micromol/L genistein group. The expression of c-erbB-2 protein were decreased, its average absorbency (A) were decreased after treatment of SKOV(3) with 20 micromol/L genistein for 48 h, reached at 0.42 +/- 0.02 (P < 0.05). Western blotting demonstrated that the expressions of c-jun and c-fos protein were decreased gradually after being treated with 20 micromol/L genistein for 12 - 72 h.

CONCLUSIONSGenistein could down-regulate the expression of two key genes, c-erbB-2 and c-raf-1 at mRNA and protein level in the EGFR mediated signal transduction pathway, and down-regulate the expression of its downstream nuclear transcription factors c-jun and c-fos at mRNA and protein level. It is suggested that interfering the expressions of some key signal molecules in EGFR mediated signal transduction system by genistein may account for its molecular foundation of proliferation inhibition in ovarian carcinoma.

Animals ; Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Female ; Gene Expression Regulation, Neoplastic ; Genes, fos ; Genes, jun ; Genistein ; pharmacology ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Ovarian Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins c-fos ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-jun ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-raf ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Receptor, Epidermal Growth Factor ; metabolism ; Receptor, ErbB-2 ; biosynthesis ; genetics ; Signal Transduction ; drug effects

To observe the effects of Panax Notoginosides (PNS) on up-regulation of AP-1 family transcription factors NF-E2, c-jun and c-fos for exploring intracellular signal pathway of PNS in hematopoietic cells, four human hematopoietic cells lines including myeloid HL-60, erythroid K562, megakaryoid CHRF-288 and Meg-01 were incubated in the presence of PNS for 14 days. The nuclear protein of cells were extracted and analyzed by Western blot with antibodies against NF-E2, c-fos and c-jun. Electrophoretic mobility shift assay (EMSA) was performed by using (32)P labeled AP-1 consensus oligonucleotide which contains binding site for NF-E2, c-jun and c-fos. The results showed that the transcription factors NF-E2, c-jun and c-fos of AP-1 family could be induced by PNS. Western blot demonstrated that the nuclear protein of both NF-E2 and c-jun in four cell lines treated by PNS were increased by 1.5-2.5- and 2.0-3.0-fold over untreated cells respectively. The c-fos protein in three cell lines of K562, CHRF-288 and Meg-01 was also elevated by 2.0-3.0-fold respectively, while c-fos protein in HL-60 cells was no detectable difference after PNS treatment. EMSA results in four cell lines indicated that AP-1 binding activity initiated by PNS was apparently elevated to form higher density band of AP-1-DNA complex. In conclusion, the intracellular transcription regulation initiated by PNS was involved in transcription factors NF-E2, c-jun and c-fos of AP-1 family members, which could play an important role in the up-regulation of genes expression related to proliferation and differentiation of hematopoietic cells.
DNA ; metabolism ; DNA-Binding Proteins ; genetics ; Erythroid-Specific DNA-Binding Factors ; Gene Expression Regulation ; drug effects ; Genes, fos ; Genes, jun ; Ginsenosides ; pharmacology ; HL-60 Cells ; Humans ; K562 Cells ; NF-E2 Transcription Factor ; NF-E2 Transcription Factor, p45 Subunit ; Panax ; Transcription Factor AP-1 ; metabolism ; Transcription Factors ; genetics ; Up-Regulation

Thrombospondin-1 (TSP-1) level is tightly regulated at the transcriptional level. To determine the detailed molecular mechanisms of TSP-1 expression, nine serial 5'-deletion constructs of the human genomic tsp-1 promoter (nucleotides -2,220 to +756) were prepared, inserted into luciferase reporter plasmids, and transiently transfected into the Hep3B human hepatocarcinoma cell. Among the nine 5'-deletion constructs, pTSP-Luc-4 (-767~+756) had consistently decreased luciferase activity with or without PMA stimulation, whereas a further truncated construct [pTSP-Luc-4' (-407~+756)] had increased levels of expression. By searching the nucleotides from -767 to -407, a consensus binding sequence (5'-CCATTTT-3') for the repressor Yin Yang-1 (YY-1) at nucleotide -440 was identified. The suppression induced by this site was weakened in the presence of the region upstream of nucleotide -767 (pTSP-Luc-1 and -2). Nuclear protein directly bound to an oligonucleotide containing the repressive YY-1 sequence but the binding capacity of the sequence was decreased by the increased c-Jun levels. Moreover, proteins immunoprecipitated with anti-YY-1 revealed an interaction between c-Jun and YY-1 factor. These data suggest that the repressive YY-1 site of the tsp-1 promoter could not be functional via activating positive cis-elements on the upstream from this site and weakened via c-Jun/YY-1 interactions.
Binding Sites/genetics ; Cell Line, Tumor ; DNA-Binding Proteins/*metabolism ; Down-Regulation/genetics ; Electrophoretic Mobility Shift Assay ; Genes, Reporter/genetics ; Humans ; Luciferases/analysis/genetics ; Promoter Regions (Genetics)/*genetics ; Proto-Oncogene Proteins c-jun/genetics/*metabolism ; Repressor Proteins/*metabolism ; Research Support, Non-U.S. Gov't ; Sequence Deletion/genetics ; Thrombospondin 1/*genetics/metabolism ; Transcription Factor AP-1/metabolism ; Transcription Factors/*metabolism

OBJECTIVETo explore JunB gene expression in spleen cells of mice after the whole body irradiation as well as in normal hematopoietic and leukemia cells in the primary culture after different dosages of X-ray irradiation.

METHODSSpleen cells were isolated from the mice irradiated with 3 Gy X-rays. Primary cultured cells from mice were incubated in different intervals after X-irradiation at different dosages. Total RNA was extracted from the cells and the fluctuation of JunB mRNA level was assessed by the RNA ratio of JunB/beta-actin measured by quantitative Northern blot hybridization.

RESULTSAfter the mice were exposed to 3 Gy X-rays irradiation, JunB expression in spleen cells was remarkably and rapidly increased, and reached its peak 0.5 h later in C3H/He mice and 1 h later in Balb/c mice. In the primary culture of normal spleen and leukemia cells, JunB mRNA levels increased 30 min after irradiation. The enhanced levels of JunB mRNA were returned to a normal level within 240 min after irradiation.

CONCLUSIONSJunB gene is responsive to ionizing irradiation and is induced at immediate-early phase after the stimulation. This suggests that the JunB gene plays an important role in the early process of the cells against radiation.

Actins ; genetics ; Animals ; Blotting, Northern ; Cell Line ; Cells, Cultured ; Gamma Rays ; Gene Expression ; radiation effects ; Genes, jun ; genetics ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C3H ; RNA, Messenger ; Spleen ; radiation effects