Induced Apoptosis In Jurkat Cells Research Articles

Effect and mechanism of Solanine on proliferation and apoptosis of Jurkat cells

Objective To explore the effect of proliferation and apoptosis of Solanine on acute T lymphocyte leukemia (T-ALL) Jurkat cells and its mechanism. Methods After treated with different concentrations of Solanine, the proliferation of Jurkat cells was detected by CCK-8 assay, and the effect of Solanine on apoptosis of Jurkat cells were detected by flow cytometry.The expression of Bcl-2 and Bax in Jurkat cells were detected by Western blot, and the expression levels of Bcl-2 mRNA and Bax mRNA were detected by real-time fluorescence quantitative polyme-rase chain reaction. Results CCK-8 assay showed that Solanine significantly inhibited the proliferation of Jurkat cells in a dose-and time-dependent manner. The results of flow cytometry showed that the apoptosis rates of Jurkat cells treated with Solanine for 24 h were (2.40±0.98)%, (28.43±4.86)%, (41.56±1.87)%, respectively, in a dose-dependent manner. Western blot showed that Solanine could increase the expression of Bax and decrease the expression of Bcl-2 in Jurkat cells, and they all were dose-dependent. Conclusion Solanine can significantly inhibit the proliferation and induce apoptosis of Jurkat cells. The mechanism is related to the up-regulation of Bax expression and down-regulation of Bcl-2 expression. Key words: Solanine; Jurkat cell; Proliferation; Apoptosis

Effects of tetramethylpyrazine injection on the proliferation and apoptosis of Jurkat cells and the relevant molecular mechanisms

Objective To study the effect of tetramethylpyrazine injection on proliferation and apoptosis of human acute lymphoblastic leukemia (ALL) cell line Jurkat and the relevant molecular mechanisms. Methods Cells were treated with tetramethylpyrazine injection at various concentrations (0, 0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 mg/ml), CCK-8 method was used to detect the inhibition rates at 24, 48 and 72 h. After cells were treated with different concentrations of tetramethylpyrazine injection (0, 0.50, 1.00 and 1.50 mg/ml) for 48 h, the cell cycle and apoptosis were detected by flow cytometry, and the Aurora-B and Survivin protein expression were analyzed by Western blot. Results Compared with the control group (cells without tetramethylpyrazine injection treatment), various concentrations of tetramethylpyrazine injection could effectively inhibit Jurkat cells proliferation in a time-and dose-dependent manner (P < 0.05), and IC50 at 24 h,48 h and 72 h after treatment were (1.33±0.16), (0.91±0.10) and (0.67±0.11) mg/ml, respectively. After cells were treated with tetramethylpyrazine injection at different concentrations (0.5, 1.0 and 1.5 mg/ml) for 48 h, the number of treated cells in G2/M phase was increased, but that in S phase was decreased, and the apoptosis rates were significantly higher than that of control group, with a dose dependence (P < 0.05). The results of Western blot showed that the expression levels of Aurora-B and Survivin in treated cells were lower than that of control group, also with a dose dependence (P < 0.05). Conclusions Tetramethylpyrazine injection can effectively inhibit proliferation and induce apoptosis of Jurkat cells in vitro, and its underlying mechanisms involve with down-regulation of the Aurora-B and Survivin protein expression. Key words: Tetramethylpyrazine injection; Leukemia; Cell proliferation; Cell apoptosis; Aurora-B; Survivin

Type 1 inositol‐1,4,5‐trisphosphate receptor is a late substrate of caspases during apoptosis

Apoptosis is characterized by the proteolytic cleavage of hundreds of proteins. One of them, the type 1 inositol-1,4,5-trisphosphate receptor (IP(3) R-1), a multimeric receptor located on the endoplasmic reticulum (ER) membrane that is critical to calcium homeostasis, was reported to be cleaved during staurosporine (STS) induced-apoptosis in Jurkat cells. Because the reported cleavage site separates the IP(3) binding site from the channel moiety, its cleavage would shut down a critical signaling pathway that is common to several cellular processes. Here we show that IP(3) R-1 is not cleaved in 293 cells treated with STS, TNFα, Trail, or ultra-violet (UV) irradiation. Further, it is not cleaved in Hela or Jurkat cells induced to undergo apoptosis with Trail, TNFα, or UV. In accordance with previous reports, we demonstrate that it is cleaved in a Jurkat cell line treated with STS. However its cleavage occurs only after poly(ADP-ribose) polymerase (PARP), which cleavage is a hallmark of apoptosis, and p23, a poor caspase-7 substrate, are completely cleaved, suggesting that IP(3) R-1 is a relatively late substrate of caspases. Nevertheless, the receptor is fully accessible to proteolysis in cellulo by ectopically overexpressed caspase-7 or by the tobacco etch virus (TEV) protease. Finally, using recombinant caspase-3 and microsomal fractions enriched in IP(3) R-1, we show that the receptor is a poor caspase-3 substrate. Consequently, we conclude that IP(3) R-1 is not a key death substrate.

The investigation of using TRAIL in vitro to remove leukemia cells from the autologous hemopoietic stem cell transplants

Objective To explore the feasibihty of TRAIL to be used to remove the leukemia cells from the autologous hemopoietic stem cell transplants. Methods The expression of decoy receptor 1 and decoy receptor 2 on the bone marrow mononuclear cell were routine-ly isolated and observed by fluorescence microscope after PE-DcR1 or PE-DcR2 stain. The apeptosis rates of mononuclearcell and Jurkat cells interfered by 200ng/ml TRAIL for 18h were determined by flow cytometry after AnnexinV/Pl stain. The interfered mononuclear cells were cultured to count the number to form colony-forming unit-fibroblast(CFU-F). The Jurkat cells labeled by green fluorescent protein were in-corporated into the mononuclear ceils and affected by 200ng/ml TRAIL for 24h. The incorporated cells were cultured in the system with GM-CSF and EPO and the numbers of the CFU-GM, BFU-E and fluorescence colony were counted on the seventh day. Results Both decoy re-ceptor land decoy receptor 2 of TRAIL can be detected on membrane or in cytoplasm of the bone marrow mononuclear cell. The apoptosis rate of mononuclear cell interfered by 200ng/ml TRAIL for 18h was (5.95±1.23)%, which was markedly lower than that of Jurkat cells (33.42±2.28) %. The number of CFU-F of TRAIL group and control group were 235.67 ~ 33.56 and 249.33±42.72, respectively. No marked difference can be found between the mentioned two groups. Moreover, TRAIL decreased the number of fluorescence colony formed by Jurkat cells without significant decreasing the number of CFU-GM and BFU-E formed by bone marrow mononuclear cells. Conclusion TRAIL can selectively induce apoptosis in Jurkat cells without marked toxic effect on the bone marrow mononuclear cells, which means that TRAIL can be used to remove the leukemia cells from the autologous hemopeietic stem cell transplants in vitro. Key words: Tumor necrosis factor/PD ; Membrane glycoproteins/PD; Hematopoietic stem cell transplantation; Leukemia

Overexpression of a C-terminal fragment of Presenilin 1 delays anti-Fas induced apoptosis in Jurkat cells

Most cases of early onset familial Alzheimer's disease (FAD) involve mutations in presenilins (PS1 and PS2) genes. The C-terminal portion of PS2 is a homologue with an apoptosis-linked gene (ALG-3). To characterise the role of PS1 in apoptosis, we overexpressed the corresponding C-terminal fragment of PS1 (PS1-f) under the control of the tetracycline-responsive transactivator in Jurkat cells. The tight regulation of the expression of the 11 kDa PS1-f peptide was verified. A 50% inhibition of anti-Fas induced apoptosis was observed upon PS1-f transient overexpression compared to the repressed state. Stable transfectants selectively overexpressing PS1-f revealed a transient protective effect of 30% after apoptosis induction.