Genes, Reporter ; Genetic Vectors ; Luciferases ; genetics ; Transcription, Genetic ; bcl-2-Associated X Protein ; genetics

The efficiency and safe range of Lipofectamine2000 (LF2000)/bcl-xl applied in human keratocytes, the optimal ratio of LF2000/bcl-xl and the bcl-xl gene expression in human keratocytes were investiaged. By using trypan-blue staining, the effects of LF2000 and bcl-xl on the survival rate of the cultured human keratocytes were measured respectively. By using semi-quantitative RT-PCR, the efficiency and the expression of LF2000-mediated bcl-xl transfection into keratocytes were examined. The results showed that the survival rate of human keratocytes had no signficant change in the presence of LF2000 (20 microg/ml) or bcl-xl (10 microg/ml) for 24 h. LF2000 could effectively mediate the transfection of exogenous gene bcl-xl into human keratocytes. The best transfection efficiency could be obtained when the ratio of bcl-xl/LF2000 was 1:8. One day after transfection, the positive cells for bcl-xl could be detectable, and the positive rate reached the peak-on the posttransfection day 3 (48.3%), then gradually decreased. Fifteen days after transfection, there were few positive cells. It was suggested that LF2000 could effectively transfer the exogenous gene bcl-xl into human keratocytes without obvious toxicity during a concentration range. LF2000/bcl-xl may be likely to play an important role in gene therapy of human keratocytes.
Cations/administration & dosage ; Cornea/cytology ; Gene Therapy ; Keratinocytes/cytology ; Keratinocytes/*metabolism ; Liposomes ; Transfection ; bcl-X Protein/biosynthesis ; bcl-X Protein/*genetics

OBJECTIVETo investigate the role of antiapoptotic Bcl-x(L) protein in megakaryocyte differentiation and maturation.

METHODSRNA interference was used to block the expression of Bcl-x(L) when K562 cells were induced to differentiate into megakaryocyte (CD61 + cells) by PDBu, and the expression of Bcl-x(L) was evaluated with flow cytometry and reverse transcription polymerase chain reaction (RT-PCR). The CD34 + cell fraction was positively isolated by using the MiniMACS system from normal bone marrow. Immunochemical staining and flow cytometry were used to detect the expression of Bcl-x(L) in the differentiation (CD41 + cells) of CD34 + cells induced by trombopoietin (TPO).

RESULTSAmong K562 cells induced by PDBu, the percentage of CD6L + cells rapidly increased in 24 hours and maintained at a high positive level in 72 hours. When exposured to si-Bcl-x(L), the percentage of CD6 1 + cells only slightly increased in 72 hours. The expression of Bcl-x(L) mRNA was significantly decreased after transfection compared with that of control group, and Bcl-x(L) protein expression decreased correspondingly. After the CD34 + bone marrow cells having been treated with TPO for 5 days to 20 days, the Bcl-x(L)-megakaryocytes increased as the culture time prolonged, and there was a strong expression of Bcl-x(L) in immature megakaryocyte and an obviously decreased expression in degenerating megakaryocytes maturation.

CONCLUSIONSIncreased expression of antiapoptotic Bcl-x(L) may be essential to mature megakaryocyte. The down-regulation of antiapoptotic Bcl-x(L) in mature megakaryocyte may be crucial to platelets formation.

Cell Differentiation ; Humans ; K562 Cells ; Megakaryocytes ; physiology ; RNA Interference ; bcl-X Protein ; biosynthesis ; genetics ; physiology

Astrocytes are a heterogenous group of macroglia present in all regions of the brain and play critical roles in many aspects of brain development, function and disease. Previous studies suggest that the B-cell lymphoma-2 associated X protein (BAX)-dependent apoptosis plays essential roles in regulating neuronal number and achieving optimal excitation/inhibition ratio. The aim of the present paper was to study whether BAX regulates astrocyte distribution in a region-specific manner. Immunofluorescence staining of SOX9 was used to analyze and compare astrocyte density in primary somatosensory cortex, motor cortex, retrosplenial cortex and hippocampus in heterozygous and homozygous BAX knockout mice at age of six weeks when cortical development has finished and glia development has reached a relatively steady state. The results showed that astrocyte density varied significantly among different cortical subdivisions and between cortex and hippocampus. In contrast to the significant increase in GABAergic interneurons, the overall and region-specific astrocyte density remained unchanged in the cortex when BAX was absent. Interestingly, a significant reduction of astrocyte density was observed in the hippocampus of BAX knockout mice. These data suggest that BAX differentially regulates neurons and astrocytes in cortex as well as astrocytes in different brain regions during development. This study provided important information about the regional heterogeneity of astrocyte distribution and the potential contribution of BAX gene during development.
Animals ; Astrocytes ; Hippocampus ; Interneurons ; Mice ; Neurons ; bcl-2-Associated X Protein/genetics*

This study was aimed to investigate the effects of gambogic acid on the cells of high-risk patients with myelodysplastic syndrome (MDS) in vitro and its mechanism. The inhibition effect of gambogic acid on growth of MUTZ-1 cell line of MDS-RAEB was detected by MTT method. Apoptosis and cell cycle were detected by morphological observation and flow cytometry respectively. The expressions of bax/bcl-2 gene at mRNA level were detected by RT-PCR. The results indicated that the Gambogic acid inhibited the growth of MUTZ-1 cells, the inhibitory rate of gambogic acid with the range of 0.2 - 0.8 microg/ml was enhanced along with increasing of drug concentration. Flow cytometric assay showed that the apoptotic rate of MUTZ-1 cells treated by gambogic acid also was enhanced along with increasing of drug concentration, the apoptotic rates resulting from gambogic acid (0, 0.4, 0.6, 0.8 microg/ml) were (5 +/- 0.5)%, (13 +/- 0.5)%, (37 +/- 0.7)% and (56 +/- 0.6)% respectively. The characteristic changes of apoptosis emerged in MUTZ-1 cells after being exposed to gambogic acid. Gambogic acid could significantly down-regulate the expressions of bcl-2 gene in a dose dependent manner, however, it had no effects on bax gene. It is concluded that within the range of concentration from 0.4 to 0. 8 microg/ml, gambogic acid can inhibit the growth of MUTZ-1 cells by inducing their apoptosis and down-regulating the expression of bcl-2 gene, which may be one of the main mechanisms underlying its antitumor effects.
Apoptosis ; drug effects ; Cell Line ; Flow Cytometry ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; RNA, Messenger ; genetics ; Xanthones ; pharmacology ; bcl-2-Associated X Protein ; genetics

This study aims to explore the effect and mechanism of Danggui Buxue Decoction(DBD)-containing serum in alleviating the H9c2 cell injury caused by the exposure to intermittent low oxygen. H9c2 cells were assigned into five groups: control(CON) group, intermittent low oxygen(IH) group, intermittent low oxygen plus DBD-containing serum(IH+DBD) group, intermittent low oxygen plus the autophagy enhancer rapamycin(IH+RAPA) group, and intermittent low oxygen plus DBD-containing serum and the autophagy inhibitor 3-methyladenine(IH+DBD+3-MA) group. Monodansylcadaverine(MDC) staining was employed to detect the changes of autophagosomes. Cell counting kit-8(CCK-8) assay was employed to determine the activity of myocardial cells, and lactate dehydrogenase(LDH) and creatine kinase(CK) kits were used to measure the LDH and CK levels in the cell culture, which would reflect the degree of cell damage. TdT-mediated dUTP nick-end labeling(TUNEL) staining was used to detect the apoptosis of myocardial cells, and JC-1 fluorescence probe to detect the changes in mitochondrial membrane potential. Western blot was employed to determine the expression levels of the autophagy-related proteins microtubule-associated proteins light chain 3Ⅱ(LC3Ⅱ), microtubule-associated proteins light chain 3Ⅰ(LC3Ⅰ), P62, Parkin and apoptosis related proteins pro caspase-3, caspase-3, B-cell lymphoma-2(Bcl-2), Bcl-2-associated X(Bax). The results showed that compared with the CON group, the IH group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated expression of P62. In addition, the IH group showed decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, and decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. Compared with the IH group, the IH+DBD and IH+RAPA groups showed increased fluorescence intensity of MDC staining, increased LC3Ⅱ/LC3Ⅰ ratio, up-regulated Parkin expression, and down-regulated P62 expression. In addition, the two groups showed increased cell survival rate, reduced content of LDH and CK in the culture medium, decreased number of TUNEL positive cells, and increased pro caspase-3/caspase-3 and Bcl-2/Bax ratios and mitochondrial membrane potential. The IH+DBD+3-MA and IH groups showed no significant differences in the above indicators. Compared with the IH+DBD group, the IH+DBD+3-MA group showed decreased fluorescence intensity of MDC staining, decreased LC3Ⅱ/LC3Ⅰ ratio, down-regulated Parkin expression, and up-regulated P62 expression. In addition, the group had decreased cell survival rate, increased content of LDH and CK in the culture medium, increased number of TUNEL positive cells, decreased pro caspase-3/caspase-3 and Bcl-2/Bax ratios, and declined mitochon-drial membrane potential. To sum up, DBD could promote the mitophagy, inhibit the apoptosis, and alleviated the injury of H9c2 cells exposed to low oxygen.
Oxygen ; bcl-2-Associated X Protein/metabolism* ; Caspase 3/genetics* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Apoptosis ; Autophagy ; Ubiquitin-Protein Ligases ; Microtubule-Associated Proteins

OBJECTIVETo observe the cell apoptosis after tractive spinal cord injury in rats, determine expression of apoptosis correlative genes, and study the molecular mechanism of cell apoptosis.

METHODSThe T(13)-L(2) spinal cord of rats was injured by traction after the amplitude of P1-N1 wave decreased to 70% in postoperation than in preoperation through cortical somatosensory evoked potential (CSEP) monitor. Then rats were killed in 30 min, 6 h, 1, 4, 7, 14 and 21 d respectively after operation (n = 4). Cell apoptosis was examined by the flow cytometer and terminal deoxynucleotidyl transferase-mediated DUTP-biotin nick end labeling (TUNEL) reaction, the expression of p53, bax and bc1-2 genes was tested with immunohistochemistry.

RESULTSThe flow cytometer test and TUNEL method showed that the apoptosis cell ratio raised in 6 h and reached at peak in 7 d after injury, and then declined till 21 d, they showed significant difference (P < 0.05, 0.01). TUNEL method showed that injured group had a large number of apoptosis glial cells in white matter. Immunohistochemical staining showed that the positive expression of p53, bax and bc1-2 protein raised at 6 h, expression of p53 protein reached at peak in 4 d, bax and bc1-2 protein reached at peak in 7 d after injury. Compared with control group and laminectomy group, the injured group showed significant difference (P < 0.05, 0.01).

CONCLUSIONThere is cell apoptosis phenomenon after tractive spinal cord injury in rats. Morphology indicates that apoptosis includes neurons and glialcytes, which is an important form of cell death and pathological changes in secondary lesion period after tractive spinal cord. There exist high expression of apoptosis correlative gene p53 and bax after spinal cord injury, they may play an important role in reduction of cells to apoptosis.

Animals ; Apoptosis ; genetics ; Disease Models, Animal ; Female ; Gene Expression ; Genes, bcl-2 ; genetics ; Genes, p53 ; genetics ; Male ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; Rats ; Rats, Sprague-Dawley ; Spinal Cord Injuries ; genetics ; pathology ; bcl-2-Associated X Protein

The study was aimed to explore the apoptosis effect of ouabain on Jurkat cells and its mechanism. MTT method was used to observe the inhibitory effect of ouabain on Jurkat cell proliferation. Apoptosis was detected by using flow cytometry (FCM) and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling reaction method (TUNEL). The protein expressions of Bax, Bcl-2 and active subunits of caspase-3 were measured by Western blot. Activities of caspase-3 were determined by colorimetry method. The results showed that ouabain could induce apoptosis of Jurkat cells, the expression of Bax protein in process of cell apoptosis, caspase-3 activity of Jurkat cells were remarkably enhanced after ouabain treatment. It is concluded that ouabain may induce apoptosis of Jurkat cells due to the activation of caspase-3 resulting from regulation of Bax protein and Bcl-2 gene expressions.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Proliferation ; drug effects ; Genes, bcl-2 ; genetics ; Humans ; Jurkat Cells ; Ouabain ; pharmacology ; bcl-2-Associated X Protein ; biosynthesis ; genetics

To explore the effects of vascular endothelial growth factor (VEGF) on the mechanisms of CML pathogenesis, the effect of VEGF on K562 cell apoptosis induced by As(2)O(3) was analyzed through morphologic observation, DNA fragmentation agarose gel electrophoresis and DNA ploidy flow cytometry analysis, and the effect of VEGF on the expression of bcl-X(L), Bax and caspase-3 in K562 cells was determined by Western blot, meanwhile the expression difference between bcl-X(L) and Bax mRNA in above conditions was detected by RT-PCR. The results showed that after VEGF added, the apoptosis of K562 cells reduced, however, there was no significant changes in cell cycle distribution (P > 0.05). At the same time, following the increasing of the concentration of VEGF, expression of mRNA and protein of bcl-X(L) was up-regulated and the expression of Bax protein was down-regulated in K562 cells, and the activation of pro-caspase-3 into caspase-3 was inhibited or reduced. It is concluded that VEGF may suppress the apoptosis of K562 cells through its influence on the bcl-X(L)/Bax expression ratio in K562 cells.
Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Blotting, Western ; Chlorides ; pharmacology ; Flow Cytometry ; Humans ; K562 Cells ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Vascular Endothelial Growth Factor A ; pharmacology ; bcl-2-Associated X Protein ; biosynthesis ; genetics ; bcl-X Protein ; biosynthesis ; genetics

Adult ; Altitude Sickness ; metabolism ; pathology ; Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Erythroblasts ; cytology ; pathology ; Humans ; Male ; Middle Aged ; RNA, Messenger ; genetics ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism