The aim of this study was to investigate the apoptosis effect of Jurkat cells induced by ursolic acid (UA) and its molecular mechanism so as to provide the theoretical basis for treatment of hematological malignancies by using UA. The cytotoxic effect of different concentration UA on Jurkat cells and inhibitory effect of caspase-9 inhibitor on cytotoxicity of UA were assayed by using WST-8 method; the Jurkat cells treated with 20 or 40 micromol/L UA for 2 or 4 hours were collected and were stained by Annexin/PI, then the apoptosis rate of Jurkat cells was detected by flow cytometry; the Jurkat cells in logarithmic growth phase were collected after treatment with different concentrations of UA for different times, the cell protein was extracted, then the activation of caspase-9, -3 and cytochrome C as well as phosphorylation level of Akt were determined by Western blot. The results indicated that the cytotoxic effect of UA on Jurkat cells was significant. UA induced apoptosis of Jurkat cells. Caspase-9, caspase-3 and cytochrome C were activated, and the phosphorylation of Akt was inhibited in the Jurkat cell apoptosis process induced by UA. It is concluded that the UA shows significant cytotoxic effect on Jurkat cells, UA can induce apoptosis of Jurkat cells through the mitochondria pathway. The mechanism may be associated with the inhibition of Akt phosphorylation.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 9 ; metabolism ; Cytochromes c ; metabolism ; Humans ; Jurkat Cells ; Triterpenes ; pharmacology

OBJECTIVETo investigate the mechanism of N- Arachidonoylethanolamine (ANA) on inhibiting platelets (PLT) apoptosis under standard blood bank storage conditions.

METHODSSamples taken from collected apheresis PLT by the Amicus instrument were split into three parts. An aliquot of 0.5 μmol/L ANA were added to one part of storage PLT as the ANA group; an aliquot of 0.5 μmol/L ANA and 1 μmol/L SR141716 was added to the another part as the ANA + SR141716 group; and the third part without ANA and SR141716 as the control group. These samples were stored on a flat-bed shaker at (22 ± 2) ⁰C for 7 days. The expression of phosphatidyl serine (PS) positive, phospho (p)-Akt, Akt, p-Bad, Bad, caspase-3, caspase-9, cytochrome C (Cyt-C) and BCL-XL interaction with Bak were detected.

RESULTSThe rate of PLT PS positive in ANA group decreased significantly than that in control group[ (8.29 ± 1.44) % vs (14.24 ± 2.47) %, P<0.05]. The release of Cyt-C from mitochondria to cytosol in ANA group decreased significantly compared with control group[ (3.29 ± 1.44) % vs (15.24 ± 3.40) %, P<0.05]. Also the expressions of p-Akt and p-Bad in ANA group increased significantly than those in control group[ (71.33 ± 10.26) % vs (35.00 ± 6.00) %, P<0.05; (39.00 ± 9.64) % vs (10.33 ± 1.53) %, P<0.05, respectively]. Higher amounts of Bak protein were co-precipitated with BCL-XL in ANA group than that in control group (about 2.6 fold, P<0.05). The expressions of cleaved caspase- 9 and caspase- 3 in ANA group decreased significantly than those in control group[ (9.63 ± 1.47) % vs (23.24 ± 2.47) %, P<0.05; (6.30 ± 1.40) % vs (13.20 ± 2.50) %, P<0.05, respectively]. There were no significantly changes between ANA+SR141716 and control groups (P>0.05).

CONCLUSIONANA protected PLTs from apoptosis as a result of inhibiting the release of Cyt-C from mitochondria to cytosol by modifying the expressions of apoptosis-relative proteins.

Apoptosis ; drug effects ; Blood Platelets ; cytology ; drug effects ; Caspase 3 ; Caspase 9 ; Cytochromes c ; Endocannabinoids ; pharmacology ; Humans ; Mitochondria ; Proto-Oncogene Proteins c-akt

Objective: To investigate the effect of arsenic and its main metabolites on the apoptosis of human lung adenocarcinoma cell line A549 and the expression of pro-apoptotic genes Bad and Bik. Methods: In October 2020, A549 cells were recovered and cultured, and the cell viability was detected by the cell counting reagent CCK-8 to determine the concentration and time of sodium arsenite exposure to A549. The study was divided into NaAsO(2) exposure groups and metobol: le expoure groups: the metabolite comparison groups were subdivided into the control group, the monomethylarsinic acid exposure group (60 μmol/L) , and the dimethylarsinic acid exposure group (60 μmol/L) ; sodium arsenite dose groups were subdivided into 4 groups: control group (0) , 20, 40, 60 μmol/L sodium arsenite NaAsO(2). Hoechst 33342/propidium iodide double staining (Ho/PI) was used to observe cell apoptosis and real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression levels of Bad and Bik mRNA in cells after exposure. Western blotting was used to detect the protein expressions of Bad, P-Bad-S112, Bik, cleaved Bik and downstream proteins poly ADP-ribose polymerase PARP1 and cytochrome C (Cyt-C) , using spectrophotometry to detect the activity changes of caspase 3, 6, 8, 9. Results: Compared with the control group, the proportion of apoptotic cells in the 20, 40, and 60 μmol/L NaAsO(2) dose groups increased significantly (P<0.01) , and the expression levels of Bad, Bik mRNA, the protein expression levels of Bad, P-Bad-S112, Bik, cleaved Bik, PARP1, Cyt-C were increased (all P<0.05) , and the activities of Caspase 3, 6, 8, and 9 were significantly increased with significantly differences (P<0.05) . Compared with the control group, the expression level of Bad mRNA in the DMA exposure group (1.439±0.173) was increased with a significant difference (P=0.024) , but there was no significant difference in the expression level of Bik mRNA (P=0.788) . There was no significant differences in the expression levels of Bad and Bik mRNA in the poison groups (P=0.085, 0.063) . Compared with the control group, the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to MMA were 0.696±0.023, 0.707±0.014, 0.907±0.031, 1.032±0.016, and there was no significant difference between the two groups (P=0.469, 0.669, 0.859, 0.771) ; the gray values of proteins Bad, Bik, PARP1 and Cyt-C exposed to DMA were 0.698±0.030, 0.705±0.022, 0.908±0.015, 1.029±0.010, and there was no difference between the two groups (P=0.479, 0.636, 0.803, 0.984) . Conclusion: Sodium arsenite induces the overexpression of Bad and Bik proteins, initiates the negative feedback regulation of phosphorylated Bad and the degradation of Bik, activates the downstream proteins PARP1, Cyt-C and Caspase pathways, and mediates the apoptosis of A549 cells.
A549 Cells ; Adenosine Diphosphate Ribose/pharmacology* ; Apoptosis ; Apoptosis Regulatory Proteins ; Arsenic ; Arsenites ; Cacodylic Acid/pharmacology* ; Caspase 3 ; Caspases/pharmacology* ; Cytochromes c/pharmacology* ; Humans ; Mitochondrial Proteins/pharmacology* ; Poisons ; Propidium/pharmacology* ; RNA, Messenger ; Sincalide/pharmacology* ; Sodium Compounds ; bcl-Associated Death Protein/metabolism*

OBJECTIVETo construct a plasmid carrying granulysin (GLS) and to study the effect of the GLS on apoptosis, mitochondrial transmembrane potential and cytochrome C release of SMMC-7721 cells.

METHODSThe coding sequence of the GLS was amplified from the total RNA of human CTL cells, and it was inserted into pBudCE4.1 plasmid and then it was used to transfect SMMC-7721 cells. The expression of GLS was detected by RT-PCR and confirmed by immunocytochemistry method. Cell apoptosis was ascertained by Hoechst staining and electron microscopy; mitochondrial transmembrane potential was detected using Mitocapture and cytochrome C release was studied using Western blot.

RESULTSRecombinant pBudCE4.1/GLS plasmid was successfully constructed. GLS protein was successfully expressed in the SMMC-7721 cells and it induced apoptosis of the SMMC-7721 cells, and at the same time, mitochondrial transmembrane potential was reduced and cytochrome C was released from mitochondria into the cytosol.

CONCLUSIONSGLS gene carried by recombinant plasmid could express in SMMC-7721 cells and induce cells apoptosis. The change of mitochondrial transmembrane potential and the release of cytochrome C might be one of the key factors of apoptosis induced by GLS.

Antigens, Differentiation, T-Lymphocyte ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cytochromes c ; metabolism ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; metabolism ; physiology

This study was purpose to investigate apoptosis pathway of leukemia K562 cells induced by anticoagulant fraction from Agkistrodon acutus venom (AVVC-1). The mitochondrial transmembrane potential (ΔΨm) of leukemia K562 cells was detected by flow cytometry with JC-1 single staining. The expression of cytochrome C in the mitochondrial of leukemia K562 cells was analyzed by Western blot after AVVC-1 treatment. The distribution of cytochrome C in leukemia K562 cells was measured by immuno-fluorescence test. The results showed that the potential of mitochondrial membrane decreased after treatment with different concentrations of AVVC-1 (12.5, 25, 50, 100 µg/ml) for 6 h (P < 0.01). The expression level of cytochrome C protein in mitochondria obviously declined after treatment with 30 µg/ml AVVC-1 for 48 h, and the fluorescent intensity of cytochrome C in cytosol was enhanced at the same time. It is concluded that AVVC-1-induced K562 cell apoptosis is related with mitochondrial damage, and cytochrome C may be a useful agent for investigating human leukemia therapy by using AVVC-1.
Agkistrodon ; Animals ; Apoptosis ; drug effects ; Cytochromes c ; metabolism ; Humans ; K562 Cells ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; metabolism ; Snake Venoms ; pharmacology

OBJECTIVETo investigate the protective effect of lycium barbarum polysaccharides (LBP) against heat stress-induced apoptosis of germ cells in rats and its action mechanism.

METHODSNinety male Sprague-Dawley rats were randomly divided into five groups of 18 each: control, heat stress (HS), high-dose LBP, median-dose LBP and low-dose LBP. The rats of the three LBP groups were given LBP by intragastric administration at 100 mg/(kg x d), 50 mg/(kg x d) and 10 mg/(kg x d) respectively for 14 days, and on the 15th day they, together with those of the HS group, were exposed to a heat of 43 degrees C for 30 minutes. At 24 h, 48 h and 7 d after heat stress, the animals were killed by cervical dislocation, followed by observation of the apoptotic germ cells by TUNEL, determination of the expression of Caspase-3 by immunohistochemistry and detection of cytochrome C in the cytosol by ELISA.

RESULTSCompared with the HS group, the three LBP groups showed statistically significant decreases in the apoptosis index (P<0.05), the expression level of Caspase-3 in germ cells (P<0.05) and the concentration of cytochrome C in the cytosol (P<0.05).

CONCLUSIONLBP can inhibit cytochrome C release from mitochondria, decrease the expression of Caspase-3 and hence reduce the apoptosis of germ cells. It thus can be deduced that LBP can protect germ cells against apoptosis via the mitochondrial pathway.

Animals ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cytochromes c ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Germ Cells ; drug effects ; Male ; Mitochondria ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

The aim of this study was to investigate the effect of cytochrome C on apoptosis of HL-60 cells and to explore the mechanism of HL-60 cell apoptosis induced by cytochrome C. The HL-60 cells were treated with different concentrations of cytochrome C for 24 hours. The concentrations of cytochrome C were as follows: 0 (control group), 9.375 mg/L, 18.75 mg/L, 37.5 mg/L, 75 mg/L and 150 mg/L. The apoptosis was analyzed by flow cytometry (FCM) after HL-60 cells were treated with different concentrations of cytochrome C for 24 hours. The fas mRNA expression changes of relevant apoptotic genes were examined by reverse transcription-polymerase chain reaction (RT-PCR) after HL-60 cells were treated with different concentrations of cytochrome C for 24 hours and were analyzed half-quantitatively. The expressions of fas involved in HL-60 treated with different concentrations of cytochrome C for 24 hours were detected by Western blot. The results indicated that the flow cytometry (FCM) (PI straining) showed obvious hypo-diploid peak before G(1) phase in the treated group, and its apoptotic ratio increased in a dose-dependent manner. The fas mRNA expression levels of the relevant apoptotic genes could be detected by RT-PCR after HL-60 cells treated with different concentrations of cytochrome C for 24 hours, and the expression of fas mRNA in HL-60 cells was increased by cytochrome C in dose-dependent manner within range of 0-37.5 mg/L. It is concluded that the cytochrome C up-regulates expressions of fas mRNA and their protein so as to induce apoptosis of the HL-60 cells.
Apoptosis ; drug effects ; Cytochromes c ; pharmacology ; Dose-Response Relationship, Drug ; HL-60 Cells ; Humans ; RNA, Messenger ; metabolism ; Up-Regulation ; fas Receptor ; metabolism

OBJECTIVETo investigate the effect of omega-3 polyunsaturated fatty acids(omega-3PUFAs) on the apoptosis of human gastric cancer cell line SGC-7901 and to explore the potential mechanisms.

METHODSCells were treated with eicosapentaenoic acid (20:5 omega-3,EPA) or docosahexaenoic acid (22:6 omega-3, DHA) at concentrations of 10, 20 and 40 microg/ml. Cell growth and apoptosis were analyzed with MTT assay, cell morphology, DNA electrophoresis and flow cytometry. Mitochondrial membrane potential ( triangle right psi mt) was measured by fluorescent probe rhodamine 123. The distribution of cytochrome C in mitochondria and cytosol was determined by enzyme-linked immunoadsorbent assay. The composition of mitochondrial membrane phospholipid(MMP)was examined by gas chromatography.

RESULTSBoth EPA and DHA markedly inhibited the SGC-7901 cell growth and induced apoptosis in a time- and dose-dependent manner. After incubation of the cells with 40 microg/ml EPA or DHA for 24 hours, the level of Deltapsimt siginificantly decreased (P<0.001), and cytochrome C largely released into cytosol from mitochondria. The proportions of EPA and DHA in MMP rapidly elevated while that of arachidonic acid sharply decreased.

CONCLUSIONSomega-3PUFAs inhibit the growth of gastric cancer cells through promoting apoptosis. Compositional and functional alterations in mitochondrial membrane may be an important initiator of apoptosis induced by omega-3PUFAs.

Apoptosis ; drug effects ; Cell Line, Tumor ; Cytochromes c ; metabolism ; Fatty Acids, Omega-3 ; pharmacology ; Humans ; Membrane Potential, Mitochondrial ; Mitochondria ; metabolism ; pathology ; Stomach Neoplasms ; metabolism

The aim of this study was to investigate apoptotic effect of 2-methoxyestradiol (2-ME2) on K562 cells and its mechanism. K562 cells were treated with different concentrations of 2-ME2. MTT assay was used to examine the effect inducing growth inhibition. DNA fragmentation assay and Annexin V-FITC/PI staining were used to detect the effect of apoptosis. The change of mitochondrial transmembrane potential was analyzed by flow cytometry. The expressions of related gene mRNA and/or proteins were detected by RT-PCR and Western blot respectively. The results indicated that the 2-ME2 inhibited proliferation of K562 cells in a time- and dose-dependent manners and the concentration of 50% growth inhibition (IC(50)) was 2 micromol/L at 48 hours. 2-ME2 induced DNA ladder and significantly increased apoptosis in K562 cells when exposed to 2 micromol/L of 2-ME2 for 24, 48 and 72 hours, the result of Annexin-V/PI staining showed that rates of the apoptotic cells were 13.78%, 22.32% and 29.43% respectively, which was remarkably higher than that of control (1.78%) (p < 0.05). The FCM analysis showed that the mitochondrial transmembrane potential in K562 cells lowered after exposed to 1, 2 and 4 micromol/L of 2-ME2 for 24 hours. 2-ME2 down-regulated the expression of bcr/abl and bcl-2, up-regulated the expression of bax mRNA, and down-regulated protein expressions of bcl-2, procaspase-3, procaspase-9, PARP (116 kD) and p-Akt, and up-regulated expression of cytoplasmic Cyto-C and PARP 85 kD apoptosis-related cleavage fragment protein, but had no effect on total Akt protein in K562 cells after treated with 2 micromol/L of 2-ME2 for 24, 48 and 72 hours. It is concluded that the 2-ME2 can induce the apoptosis and inhibit the proliferation of K562 cells by increasing the ratio of bax/bcl-2, reducing the mitochondrial transmembrane potential, releasing cytochrome C to cytoplasm, initiating the mitochondrial apoptosis pathway and leading in turn to caspase-3 activation. These findings suggest that interfere PI3K/Akt signal pathway via down-regulating the expression of bcr/abl mRNA is implicated in the effect of 2-ME2 on K562 cells.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cytochromes c ; metabolism ; Down-Regulation ; Estradiol ; analogs & derivatives ; pharmacology ; Humans ; K562 Cells ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Messenger ; genetics

OBJECTIVEIn order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored.

METHODS[3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells.

RESULTSTroglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone.

CONCLUSIONThe findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Chromans ; pharmacology ; Cytochromes c ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; HT29 Cells ; Humans ; PPAR gamma ; metabolism ; Proline Oxidase ; metabolism ; Reactive Oxygen Species ; metabolism ; Thiazolidinediones ; pharmacology