This study was aimed to investigate the relation of MCL-1 and BAK proteins with incidence and development of nutritional anemia (NA) and their clinical significance. The MCL-1 and BAK protein levels in serum of 66 patients with NA were determined by using ELISA. Eighteen healthy people were randomly selected as normal controls. The results indicated that: (1) as compared with normal control group, the expression level of MCL-1 protein in 3 NA groups (iron-deficiency anemia, macrocytic anemia, mixed anemia) significantly decreased (P < 0.001), while the expression level of BAK protein obviously increased (P < 0.001), but the expression level of MCL-1 and BAK proteins among 3 NA groups showed no obvious differences; (2) the MCL-1 protein expression level increased and BAK protein expression level decreased in 3 NA groups after treatment (P < 0.05). (3) there was negative correlation of expression levels of MCL-1 protein with BAK protein in NA group (r = -0.858 P < 0.05). It is concluded that the MCL-1 and BAK proteins may play an important role in the incidence and development of NA, and can be used as the assist index for defining diagnosis and evaluate prognosis of NA.
Anemia ; metabolism ; pathology ; Apoptosis ; Case-Control Studies ; Humans ; Malnutrition ; metabolism ; pathology ; Myeloid Cell Leukemia Sequence 1 Protein ; metabolism ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism

OBJECTIVETo investigate the growth inhibition effect, cytotoxicity and apoptotic induction of harringtonine (HT) in human acute promyelocytic leukemia (APL) NB4 cells,and the related mechanism.

METHODSNB4 cells were treated with HT. Total cell numbers were counted by hemocytometer, and cell viabilities were determined by trypan blue exclusion. Apoptotic cells were determined by fluorescence microscopy and FACS after staining with AO and EB or PI, respectively. The cleavage of PARP and the activation of Bax and the expression of anti-apoptotic proteins were determined by Western Blot. siRNA was used to silence the expression of target genes. Primary cells were isolated following Ficoll-Hypaque density gradient centrifugation method.

RESULTSHT inhibited cell growth and induced apoptosis of NB4 cells in a dose- and time-dependent manner. Apoptosis induced by HT was correlated with the down-regulation of Mcl-1 and the cleavage of PARP, while HT did not affect the protein level of Bax and Bak or change the protein level of Bcl-2. The silence of Bcl-XL sensitized HT-induced apoptosis in NB4 cells.Apoptosis induced by HT in primarily cultured APL cells was also correlated with the down-regulation of Mcl-1.

CONCLUSIONHT inhibits cell growth and induces apoptosis in NB4 cells and primarily cultured APL cells, which may be associated with down-regulation of Mcl-1.

Apoptosis ; drug effects ; Cell Line, Tumor ; Harringtonines ; pharmacology ; Humans ; Leukemia, Promyelocytic, Acute ; metabolism ; pathology ; Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism ; bcl-2-Associated X Protein ; metabolism

PURPOSE: This study examined the effects of Tacrolimus (FK506) on the expression of the apoptotic signal transduction proteins of Jurkat human T-lymphocytes. METHODS: The cell viability was examined by a MTT assay, DAPI stain, enzyme activity of caspase family proteins, and western blotting for Bcl-2, Bak, Fas, and Fas-L. The cells were cultured in the presence or absence of FK506. FK506 induced cell death was confirmed to be apoptosis by the observation of nuclear fragmentation. RESULTS: The viability of Jurkat cells was decreased by the addition of FK506 in a dose- and time- dependent manner. The FK506 induced activation of caspase-3 protease was observed. FK506 didn't increase the catalytic activity of caspase -6, -8, and -9 proteases of Jurkat cells in a time-dependent manner. The viability was improved when a caspase-3 inhibitor was added. However, the caspase-9 inhibitor did not affect the viability. Bak protein expression was increased, and the Bcl-2 protein was decreased for some time. The expression of Fas and Fas-L were unaffected by FK506. CONCLUSION: FK506 induces dose- and time-dependent apoptotic cell death, and enhances the apoptosis of Jurkat cell by increasing the expression of Bak and caspase-3.
Apoptosis ; bcl-2 Homologous Antagonist-Killer Protein ; Blotting, Western ; Caspase 3 ; Caspase 9 ; Cell Death ; Cell Survival ; Humans ; Jurkat Cells ; Peptide Hydrolases ; Signal Transduction* ; T-Lymphocytes ; Tacrolimus*

OBJECTIVETo investigate miR- 125b regulation mechanism by identifying miR-125b target genes and its function in acute myeloid leukemia (AML).

METHODSThe bioinformatics software and database were applied to predict and analyze target genes of miR-125b. The vector contained the target gene 3'-UTR portion cloned into a luciferase reporter construct. A luciferase reporter assay was performed following co-transfection of small molecular miR-125b mimics and target gene wild-type or mutant plasmid into HEK-293T cells. Further in leukemia cell lines NB4 and HL-60, the protein level of target gene was measured by Western blot after overexpression miR-125b. Finally, the viabilities of NB4 and HL-60 cells were measured by CCK-8 assay at 24 h, 48 h, 72 h, 96 h after electroporation.

RESULTSBcl-2-antagonist/killer 1 (Bak1), a pro-apoptotic gene, was a target gene of miR-125b by software predicts. Reporter vector containing the 3'-UTR Bak1 wild and mutation sites were co-transfected with small molecule analogues of miR-125b in HEK-293T cells. Dual luciferase reporter gene assay system showed that miR-125b significantly suppresses the reporter gene activity containing Bak1 3'-UTR by about 53.8% (P<0.05), but it didn't suppresses the reporter gene activity containing 3'-UTR Bak1 mutation. Western blot showed that miR-125b mimics significantly down-regulated the expression of Bak1 in human leukemia cell lines NB4 and HL-60. Meanwhile, the growth rate of cells treated with miR-125b obviously increased compared with that in control by CCK-8 test (P<0.05).

CONCLUSIONOur findings strongly indicated that BAK1 was a downstream target gene of miR-125b, and miR-125b promoted proliferation in human AML cells at least partially by targeting Bak1, so we speculated that miR-125b as an oncogene could be a potential therapeutic target for treating AML.

Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; HEK293 Cells ; HL-60 Cells ; Humans ; MicroRNAs ; genetics ; Transfection ; bcl-2 Homologous Antagonist-Killer Protein ; genetics ; metabolism

Palmitic acid (PAM), one of the most common saturated fatty acid (SFA) in animals and plants, has been shown to induce apoptosis in exocrine pancreatic AR42J cells. In this study, we investigated cellular mechanisms underlying protective effects of oleic acid (OLA) against the lipotoxic actions of PAM in AR42J cells. Exposure of cells to long-chain SFA induced apoptotic cell death determined by MTT cell viability assay and Hoechst staining. Co-treatment of OLA with PAM markedly protected cells against PAM-induced apoptosis. OLA significantly attenuated the PAM-induced increase in the levels of pro-apoptotic Bak protein, cleaved forms of apoptotic proteins (caspase-3, PARP). On the contrary, OLA restored the decreased levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-xL, and Mcl-1) in PAM-treated cells. OLA also induced up-regulation of the mRNA expression of Dgat2 and Cpt1 genes which are involved in triacylglycerol (TAG) synthesis and mitochondrial beta-oxidation, respectively. Intracellular TAG accumulation was increased by OLA supplementation in accordance with enhanced expression of Dgat2 gene. These results indicate that restoration of anti-apoptotic/pro-apoptotic protein balance from apoptosis toward cell survival is involved in the cytoprotective effects of OLA against PAM-induced apoptosis in pancreatic AR42J cells. In addition, OLA-induced increase in TAG accumulation and up-regulation of Dgat2 and Cpt1 gene expressions may be possibly associated in part with the ability of OLA to protect cells from deleterious actions of PAM.
Animals ; Apoptosis ; bcl-2 Homologous Antagonist-Killer Protein ; Cell Death ; Cell Survival ; Gene Expression ; Humans ; Oleic Acid ; Palmitic Acid ; Proteins ; RNA, Messenger ; Triglycerides ; Up-Regulation

OBJECTIVETo investigate the inhibitory effect of small interfering RNA (siRNA) targeting Bax-Bak on the apoptosis of human granulosa cells.

METHODSHuman granulosa cells were transfected with Bax-siRNA and Bak-siRNA either alone or in comibnation, and the cell morphological changes were obsered and the cell apoptosis was detected with flow cytometry. Western blotting was performed to examine the changes in Bax and Bak expressions in the transfected cells.

RESULTSWestern blotting demonstrated significantly weakened expressions of Bax and Bak in the transfected cells. The cell morphology of the cells tranfected with Bak siRNA and with both Bak and Bax siRNA remained normal; the cells with exclusive Bax siRNA transfection presented with basically normal cell morphology, but black spots were noted in the cytoplasm. In the positive and negative control groups, the cells became rounded and shrank with expanded intercellular spaces and numerous black spots in the cytoplasm. Flow cytometry showed apoptotic indexes of 3.44% and 3.97% in cells transfected with Bak siRNA and Bax-Bak siRNA, respectively, significantly lower than that in the negative group. Bax siRNA transfection resulted in an apoptotic index of 19.98%, similar to that in the negative group.

CONCLUSIONInterference of the expression of Bak gene inhibits the apoptosis of human granulosa cells, and the inhibitory effect can be enhanced by simultaneous Bax interference, which, when used alone, does not obviosuly inhibit the apoptosis of human granulosa cells.

Apoptosis ; genetics ; Cells, Cultured ; Female ; Granulosa Cells ; cytology ; Humans ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection ; bcl-2 Homologous Antagonist-Killer Protein ; genetics ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

This study was aimed to investigate the effects of valproic acid sodium (VPA) on the proliferation and apoptosis of acute T-lymphoblastic leukemia Jurkat cells. Jurkat cells were treated with different concentration of VPA. Proliferation-inhibition curve was assayed and plotted by CCK-8 method and the cell apoptosis was detected by flow cytometry with Annexin V/PI double staining. The expression level of anti-apoptotic gene BCL-2 and pro-apoptosis gene Bak1 were detected by semi-quantitative RT-PCR. The results showed that the VPA inhibited the proliferation of Jurkat cells in concentration-dependent manner. As compared with the control group, the apoptosis of cells increased along with adding concentration of VPA; VPA could decrease the expression of BCL-2 gene, but did not show obvious effect on the expression of Bak1. It is concluded that the VPA can inhibit proliferation of Jurkat cells which possibly associates with the decrease of BCL-2 expression.
Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Humans ; Jurkat Cells ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Sodium ; pharmacology ; Valproic Acid ; pharmacology ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism

Baicalin is flavonoid and major component of PC-SPES. Flavonoids including baicalin have been reported to not only function as anti-oxidant but also cause cytotoxic effect. Baicalin hydrate has been reported to induce cell death, however the mechanism by which baicalin hydrate induces the apoptosis of cancer cells is still unclear. To evaluate the mechanistic insights of apoptosis by baicalin hydrate, we tested the activities of apoptosis signaling pathway in HeLa cells. The viability of HeLa and HeLa s3 cells was markedly decreased by baicalin hydrate in a dose- and time- dependent method. Baicalin hydrate induced the apoptotic death of HeLa cells, which was characterized by the chromatin condensation of the nuclei and phosphorylation of histone H2AX. Baicalin hydrate increased the sub-G1 DNA content of HeLa cell lines. Baicalin hydrate digested Bid protein, increased Bak protein level and also, induced mitochondrial dysfunction disrupted as shown as the mitochondrial membrane potential. It activated caspase-3, thereby resulted in cleavage of poly (ADP) ribose polymerase (PARP).
Apoptosis ; bcl-2 Homologous Antagonist-Killer Protein ; BH3 Interacting Domain Death Agonist Protein ; Caspase 3 ; Cell Death ; Chromatin ; DNA ; Flavonoids ; HeLa Cells ; Histones ; Humans ; Membrane Potential, Mitochondrial ; Phosphorylation ; Ribose ; Signal Transduction*

One group of Bcl-2 protein family, which shares only the BH3 domain (BH3-only), is critically involved in the regulation of programmed cell death. Herein we demonstrated a novel human BH3-only protein (designated as Bop) which could induce apoptosis in a BH3 domain-dependent manner. Further analysis indicated that Bop mainly localized to mitochondria and used its BH3 domain to contact the loop regions of voltage dependent anion channel 1 (VDAC1) in the outer mitochondrial membrane. In addition, purified Bop protein induced the loss of mitochondrial transmembrane potential (Δψm) and the release of cytochrome c. Furthermore, Bop used its BH3 domain to contact pro-survival Bcl-2 family members (Bcl-2, Bcl-X(L), Mcl-1, A1 and Bcl-w), which could inhibit Bop-induced apoptosis. Bop would be constrained by pro-survival Bcl-2 proteins in resting cells, because Bop became released from phosphorylated Bcl-2 induced by microtubule-interfering agent like vincristine (VCR). Indeed, knockdown experiments indicated that Bop was partially required for VCR induced cell death. Finally, Bop might need to function through Bak and Bax, likely by releasing Bak from Bcl-X(L) sequestration. In conclusion, Bop may be a novel BH3-only factor that can engage with the regulatory network of Bcl-2 family members to process intrinsic apoptotic signaling.
Amino Acid Sequence ; Animals ; Apoptosis ; Cell Line ; Cell Survival ; Humans ; Mice ; Mitochondria ; metabolism ; Mitochondrial Membranes ; metabolism ; Molecular Sequence Data ; Protein Structure, Tertiary ; Protein Transport ; Proto-Oncogene Proteins c-bcl-2 ; chemistry ; metabolism ; Signal Transduction ; Time Factors ; Voltage-Dependent Anion Channel 1 ; metabolism ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism ; bcl-2-Associated X Protein ; metabolism

PURPOSE: Rapamycin (RPM) and its analogues are known for their potent immunosuppressant and anti-proliferative properties, which stem from their ability to modulate the signal transduction pathways involved in cell cycle progression from the G1 to S phase. Thus, RPM has been shown to inhibit the proliferation of a number of non-immune cell types, including hepatocytes, vascular smooth cells and fibroblasts. In addition to its effects on proliferation, RPM may also play a role in the regulation of apoptosis under certain circumstances. METHODS: The effects of RPM on the activation, proliferation and expression of cytotoxic effector molecules were examined on Molt-4 human T-lymphocyte by determining its effects on apoptosis, cell viability, reactive oxygen species (ROS) production and mitochondrial dysfunction. Cells were cultured in the presence or absence of RPM, and then analyzed by Flow cytometry after staining with PI (propidium iodide). RESULTS: The viability of Molt-4 T cells dose- and time-dependently decreased on the addition of RPM. CONCLUSION: RPM induced cytotoxicity was characterized by G2/M phase cell cycle arrest. In addition, a pharmacological scavenging study of ROS, including H2O2, revealed the cytotoxicity was mainly induced by the generation of ROS, which might modulate the expression of Bak protein and mitochondrial dysfunction.
Apoptosis ; bcl-2 Homologous Antagonist-Killer Protein ; Cell Cycle Checkpoints* ; Cell Cycle* ; Cell Survival ; Fibroblasts ; Flow Cytometry ; Hepatocytes ; Humans ; Reactive Oxygen Species ; S Phase ; Signal Transduction ; Sirolimus* ; T-Lymphocytes*