OBJECTIVETo study the molecular mechanism of microcystin (MC) induced liver tumorigenesis in rats.

METHODSThe two-stage-medium-term tumorigenesis theory was applied to establish the animal model, and the effect of MC in liver tumor formation was evaluated by the Albert gamma-GT methods, and then, the immunohistochemical technique and image analysis were used to study the expression of the bcl-2 and bax genes during tumorigenesis.

RESULTS(1) MC enhanced the formation of gamma-GT foci in liver (100%), which was significantly higher than the diethylnitrosamine (DEN) control group (22.22%) (P < 0.05). (2) MC decreased the expression of bax gene. The intensity and area of bax gene expression in the pure MC toxin group were 0.028 3 AODV and 0.007 3 ( micro m(2)/ micro m(2)) and in the DEN control group were 0.065 5 AODV and 0.024 4 ( micro m(2)/ micro m(2)), respectively. The intensity and areas of bax gene expression in the pure MC toxin group were significantly lower than those in the DEN control group (P < 0.05). (3) MC increased the expression of bcl-2 gene. The intensity and area of bcl-2 gene expression in the pure MC toxin group wee 0.097 7 AODV and 0.031 5 ( micro m(2)/ micro m(2)), respectively, and in the DEN control group were 0.046 0 AODV and 0.020 5 ( micro m(2)/ micro m(2)) respectively (P < 0.05).

CONCLUSION(1) MC can strongly promote liver tumorigenesis. (2) The changes of bcl-2 and bax gene expression possibly play an important role in the MC induced liver tumor formation.

Animals ; Carcinogens ; toxicity ; Immunohistochemistry ; Liver ; drug effects ; metabolism ; pathology ; Liver Neoplasms ; chemically induced ; metabolism ; pathology ; Mice ; Microcystins ; Peptides, Cyclic ; toxicity ; Proto-Oncogene Proteins ; biosynthesis ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein

OBJECTIVESTo explore the effect of lead acetate on the apoptosis of rat brain neural cells and the relationship between the apoptosis and the bcl-2 as well as bax gene expression.

METHODSLead acetate was given to SD rats by intraperitoneal injection for 5 days at the dosage of 25, 50 and l00 mg/kg body weight respectively. The rates of apoptosis and the expression of bcl-2 (Bcl-2) and bax (Bax) in neural cells from cerebral cortex, hippocampus and carebellum were measured respectively by flow cytometry (FCM).

RESULTSThe rates of apoptosis in neural cells from cerebral cortex, hippocampus and cerebellum in every treatment group were significantly higher than that of control (P < 0.01), and there was a significant dose-response relationship (r = 0.998, 0.989 and 0.997 respectively). The expression of bcl-2 was significantly decreased, whereas bax was significantly increased, in neural cells from cerebral cortex, hippocampus and cerebellum in every lead acetate treatment group (FI) compared with the control group, and there was a significant dose-response relationship (r = -0.886, -0.787 and -0.832 respectively for bcl-2, r = 0.971, 0.988 and 0.991 respectively for bax). The value of Bcl-2/Bax in every treatment group decreased significantly compared with control, and there was a nice dose-response relationship (r = -0.863, -0.829 and -0.999, respectively). Correlation analysis showed that rates of apoptosis were inversely correlated with the expression of bcl-2 (r = -0.750, -0.509, and -0.667, respectively), whereas positively correlated with the expression of bax (r = 0.748, 0.56l, and 0.668, respectively). And there were inverse correlations between the rates of apoptosis and Bcl-2/Bax expression.

CONCLUSIONLead may induce apoptosis in rat brain neural cells through the down regulation of bcl-2 and the up regulation of bax gene expression.

Animals ; Apoptosis ; Brain ; cytology ; drug effects ; metabolism ; Female ; Male ; Organometallic Compounds ; administration & dosage ; pharmacology ; Proto-Oncogene Proteins ; biosynthesis ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein

OBJECTIVESTo investigate the relationship between germ cell apoptosis and expression of Bcl-2 and Bax in experimental torsed/detorsed testes of the adult male rats.

METHODSThirty healthy male Sprague-Dawley rats were divided into torsion group (n = 15) and control group (n = 15) randomly. Animals were submitted to unilateral 720 testicular torsion, then detorsion were done in two hours. Three days later, the evidence of germ cell apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique. The expression of Bcl-2 and Bax were detected by immunohistochemical method.

RESULTSIn the torsed testes, the apoptosis index of germ cell and Bax expression significantly increased compared with that in the control group (P < 0.01) while Bcl-2 expression obviously decreased (P < 0.01). The apoptotic cells were mostly pechytene spermatocytes and round spermatides.

CONCLUSIONSThe germ cell apoptosis is highly associated with expression of Bcl-2 and Bax in experimental testicular torsion. Bcl-2/Bax plays an important role in germ cell apoptosis.

Animals ; Apoptosis ; Gene Expression ; Germ Cells ; pathology ; Male ; Proto-Oncogene Proteins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; Spermatic Cord Torsion ; metabolism ; pathology ; bcl-2-Associated X Protein

OBJECTIVETo study the relationship between the expression of Bax, Bcl-2 proteins, and apoptosis in radiation compound wound healing of rats.

METHODSApoptosis, Bax and Bcl-2 proteins were estimated by in situ terminal labeling (TUNEL) and immunohistochemical methods.

RESULTS(1) Changes of the apoptosis in wound healing showed three typical characteristics: early occurrence, high frequency and delayed disappearance after radiation to rats when compared with those of simple wound group, which might be an important reason for radiation-induced delayed wound healing. (2) The expression of Bax protein increased evidently with the increment of apoptosis and showed a good corresponding relationship with the apoptotic frequency in the process of wound healing. While the expression of Bcl-2 protein decreased obviously as the apoptosis reached a maximum and showed increasing tendency up to normal level when the apoptosis decreased distinctively.

CONCLUSIONSBax and Bcl-2 proteins play an important role in the apoptotic regulation of radiation compound wound healing in rats.

Animals ; Apoptosis ; radiation effects ; Female ; Gamma Rays ; Immunohistochemistry ; Proto-Oncogene Proteins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Skin ; pathology ; radiation effects ; Wound Healing ; genetics ; radiation effects ; bcl-2-Associated X Protein

To observe the effect of ginsenoside Re on cardiomyocyte apoptosis and Bcl-2/Bax gene expression after ischemia (30 min) and reperfusion (6 h) in rats and to elucidate the possible mechanisms of ginsenoside Re on inhibition of cardiomyocyte apoptosis, the ischemia/reperfusion heart model was established by ligating the left anterior descending branch of coronary artery in Wistar rats. The apoptotic cardiomyocytes were confirmed by transmission electron microscopy and counted by in situ nick end labeling (TUNEL) method and light microscopy. The mRNA and protein expression of Bcl-2 and Bax genes were studied by in situ hybridization and immunohistochemical staining. Mean optical density (OD) value of the positive fields of mRNA and protein expression was quantitatively examined by image analysis system. The results were as follows: (1) The apoptotic cardiomyocytes were found in ischemic fields in the ischemia/reperfusion group and weren't observed in the sham-operation group by transmission electron microscopy; (2) The numbers of the apoptotic cells were 134.45 +/- 45.61/field in the ischemia/reperfusion group, and 90.66 +/- 19.22/field in the ginsenoside Re-treated group. The differences was significant between two groups (P < 0.01); (3) Gene expression of Bcl-2 and Bax were increased significantly in the ischemia/reperfusion group and ginsenoside Re-treated group when compared with the sham-operation group. There was no significant difference in the gene expression of Bcl-2 between the ginsenoside Re-treated group and ischemia/reperfusion group (P > 0.05), but gene expression of Bax was decreased significantly in the ginsenoside Re-treated group as compared with the ischemia/reperfusion group (P < 0.01). The ratio of Bcl-2/Bax was increased significantly in the ginsenoside Re-treated group when compared with the ischemia/reperfusion group and sham-operation group. These findings suggest that myocardial ischemia-reperfusion can induce cardiomyocyte apoptosis, and ginsenoside Re can significantly inhibit cardiomyocyte apoptosis induced by ischemia-reperfusion in rats. It is concluded that ginsenoside Re inhibits cardiomyocyte apoptosis by inhibiting expression of pro-apoptotic Bax gene and raising the ratio of Bcl-2/Bax.
Animals ; Apoptosis ; drug effects ; Female ; Ginsenosides ; pharmacology ; Male ; Myocardial Reperfusion Injury ; genetics ; pathology ; Myocytes, Cardiac ; metabolism ; pathology ; Panax ; Proto-Oncogene Proteins ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein

To investigate whether the Bcl-2 gene family is involved in modulating mechanism of apoptosis and change of cell cycle protein induced by curcumin in acute myeloid leukemia HL-60 cell line and primary acute myelogenous leukemic cells, the Bcl-2 family member Mcl-1, Bax and Bak and cell cycle proteins including P27kipl, P21wafl, cyclin D3 and pRbp- were selected and their expression detected by SABC immuno-histochemical stain method. The attitude of sub-G1 peak in DNA histogram was determined by FCM. The TUNEL positive cell percentage was identified by terminal deoxynucleotidyl transferase (TdT)-mediated Biotin dUNP end labeling technique. It was found that when HL-60 cells were treated with 25 mumol/L curcumin for 24 h, the expression level of Mcl-1 was down-regulated, but that of Bax and Bak up-regulated time-dependently. There was significant difference in the expression level of Mcl-1, Bax and Bak between the curcumin-treated groups and control group (P < 0.05-0.01). At the same time, curcumin had no effect on progress of cell cycle in primaty acute myelogenous leukemia at newly diagnosis, but could increase the peak of Sub-G1 (P < 0.05), and down-regulate the expression of Mcl-1 and up-regulate the expression of Bax and Bak with the difference being statistically significant. The expression of P27kipl, P21wafl and pRbp- were elevated and that of cyclin D3 decreased in the presence of curcumin. These findings suggested that the Bcl-2 gene family indeed participated in the regulatory process of apoptosis induced by curcumin in HL-60 cells and AML cells. Curcumin can induce apoptosis of primary acute myelogenous leukemic cells and disturb cell cycle progression of HL-60 cells. The mechanism appeared to be mediated by perturbing G0/G1 phases checkpoints which associated with up-regulation of P27kipl, P21wafl and pRbp- expression, and down-regulation of cyclin D3.
Antineoplastic Agents, Phytogenic/pharmacology ; Apoptosis/*drug effects ; Cell Cycle Proteins/*metabolism ; Curcumin/*pharmacology ; Genes, bcl-2/genetics ; HL-60 Cells ; Leukemia, Myelocytic, Acute/pathology ; Neoplasm Proteins/biosynthesis ; Neoplasm Proteins/genetics ; Proto-Oncogene Proteins/biosynthesis ; Proto-Oncogene Proteins/genetics ; Proto-Oncogene Proteins c-bcl-2/*metabolism ; Tumor Cells, Cultured ; bcl-2-Associated X Protein

OBJECTIVETo explore the effects of hyperbaric oxygen (HBO) treatment on the neuronal apoptosis at an earlier stage and the expressions of Cytochrome C (Cyt C), Bcl-2 (B-cell lymphoma-2 family) and Bax (Bcl-2 associated X protein) in rat brain tissues after traumatic brain injury (TBI).

METHODSForty adult rats were divided into two groups, i.e., Group A (the rats with untreated TBI) and Group B (rats with HBO treatment after TBI). Sections of brain tissues of these two groups were then detected at 3, 6, 12, 24, 72 hours after TBI by immunohistochemistry and electronmicroscope, respectively.

RESULTSHBO treatment could up-regulate the expression of Bcl-2 within 72 hours, reduce the release of Cyt C from mitochondria, attenuate the formation of dimeric Bax and alleviate the mitochondrial edema within 24 hours after TBI.

CONCLUSIONSHBO treatment can alleviate neuronal apoptosis after TBI by reducing the release of Cyt C and the dimers of Bax and up-regulating the expression of Bcl-2.

Analysis of Variance ; Animals ; Apoptosis ; physiology ; Brain Injuries ; pathology ; therapy ; Cytochromes c ; biosynthesis ; Disease Models, Animal ; Hyperbaric Oxygenation ; Immunohistochemistry ; Male ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; biosynthesis

Aldehydes ; pharmacology ; Animals ; Anthracenes ; pharmacology ; Cell Line ; Cell Proliferation ; drug effects ; Hepatocytes ; cytology ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; Proto-Oncogene Proteins c-myc ; biosynthesis ; genetics ; Rats

OBJECTIVETo investigate the changes in the expressions of Bcl-2 protein and C-myc protein in the spermatogenic cells of rats after exposure to high power microwave (HPM) and to elucidate the possible mechanisms underlying the apoptosis induced by HPM at the genetic translation level.

METHODSOne hundred and twenty-five healthy male SD rats were divided randomly into unexposed control and experimental groups. The latter were radiated with S wave band 10 W/cm2, 20 W/cm2 HPM for 5 min and 10 min. Testicular samples were taken 6 h, 24 h, 48 h, 72 h and 120 h after radiation and studied respectively. Five blank radiation groups served as controls. Then immunohistochemical SP staining was performed to test the expressions of Bcl-2 protein and C-myc protein in the spermatogenic cells in the rats.

RESULTSThe expression of Bcl-2 protein in the 24 h group was up-regulated after radiated for 5 minutes and 10 minutes by HPM, higher in the 20 mW/cm2 group than in the 10 mW/cm2 group (P < 0.01). There was no expression of C-myc/Bcl-2 protein in the control group.

CONCLUSIONExposure to HPM for 24 h can up-regulate the expressions of C-myc protein and Bcl-2 protein in the spermatogenic cells of rats, which might be one of the mechanisms of the apoptosis induced by HPM.

Animals ; Apoptosis ; radiation effects ; Male ; Microwaves ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; Proto-Oncogene Proteins c-myc ; biosynthesis ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spermatozoa ; metabolism ; Testis ; cytology ; metabolism ; radiation effects

OBJECTIVE: To investigate the effects of long-term estrogen replacement treatment (ERT) on the expression of bcl-2 and H-ras in rat endometrium. METHODS: Thirty 5-month-old SD female rats were randomly divided into 3 groups: Control group ( sham operated and vehicle injected, n 10) , OVX group (OVX operated and vehicle injected, n = 10) , and ERT group (OVX operated and 17 beta-estradiol injected, n = 10). The rats were killed in the 13th week and the uteri were isolated and weighed, pathologically analyzed, and we measured the thickness of the endometrium. Immunochemistry and in situ hybridization analysis were used to examine the changes of bcl-2 and H-ras mRNA and Bcl and H-ras protein expression in the endometrium of the rats. RESULTS: Uterine weight and endometrial thickness of OVX decreased much more than those of the control (P <0.01 ) and ERT rats (P < 0.01). One simple hyperplasia and one squamous metaplasia of endometrium were found in ERT rats. Quantitatively, bcl-2 and H-ras mRNA and Bcl and H-ras protein level of ERT were higher than those of OVX rats (P < 0.01 ), and there were no statistical significances between the ERT group and the control rats. CONCLUSION Long-term estrogen replacement can keep the endometrium from atrophy, and lead to the genesis of simple hyperplasia and squamous metaplasia of the endometriun, which can increase the risk of endometrial carcinomas. Estrogen may inhibit apoptosis and promote the proliferation of endometrial cells through increasing the expression of bcl-2 and H-ras mRNA and Bcl-H-ras proteins.
Animals ; Endometrium ; metabolism ; Estradiol ; pharmacology ; Estrogen Replacement Therapy ; Female ; Genes, bcl-2 ; Genes, ras ; Ovariectomy ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Time Factors ; ras Proteins ; biosynthesis ; genetics