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*

The permeability of mitochondrial outer membrane (MOM) is regulated by the proteins of the Bcl-2 family via their interactions at the membrane. While pro-apoptotic Bax protein promotes MOM permeabilization (MOMP) releasing cytochrome c after activation by BH3-only protein, anti-apoptotic Bcl-2 protein protects MOM. However both Bax and Bcl-2 can form pores in model membranes. Unlike Bax pore that has been extensively studied and reported to be directly linked to MOMP, Bcl-2 pore is much less known; thus we investigated the pore-forming property of recombinant Bcl-2 lacking the C-terminal transmembrane sequence (Bcl-2deltaTM) in liposomal membranes of MOM lipids. We found that: (1) Bcl-2 formed pores at acidic pH that induced the association of Bcl-2 with liposome; (2) Bcl-2 pore size was dependent on Bcl-2 concentration, suggesting that oligomerization is involved in Bcl-2 pore formation; (3) Unlike Bax pore that could release large molecules up to 2 mega-Da, Bcl-2 pore was smaller and could only release the molecules of a few kilo-Da. Therefore, Bcl-2 and Bax may form different size pores in MOM, and while the large pore formed by Bax may release cytochrome c during apoptosis, the small pore formed by Bcl-2 may maintain the normal MOM permeability.
BH3 Interacting Domain Death Agonist Protein ; metabolism ; Cell Membrane Permeability ; Cytochrome c Group ; metabolism ; Humans ; Hydrogen-Ion Concentration ; Liposomes ; metabolism ; Mitochondrial Membrane Transport Proteins ; metabolism ; Mitochondrial Membranes ; metabolism ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism

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

The purpose of study was to explore the possible functions of Bcl-xL in the glucosamine sulfate-induced apoptosis of chronic myeloid leukemia K562 cells. Light microscopy and Wright-Giemsa staining were used to investigate the morphologic evidences for apoptosis of K562 cells induced by glucosamine sulfate (GS); immunofluorescence was used to observe the translocation of cathepsin D and cytochrome C during the apoptosis; Western blot was performed to detect the expression of Bcl-xL, Bid, Bax in K562 cells treated by GS. The results showed that many vacuoles were observed in the cytoplasma of the K562 cells treated by GS; fluorescent signals of cathepsin D and cytochrome were fransformed from granules to disperse form by using immunofluorescence; the expression of Bcl-xL was found down-regulated in K562 cells treated by GS, but not in the cells pre-treated with pepstatin A; the significant changes were not detected in expression of Bax and Bid protein before or after apoptosis. It is concluded that Bcl-xL protein may mediate relationship between cathepsin D and mitochondia pathway, Cathepsin D may play an important role in the GS inducing apoptosis of K562 cells through downregulation of Bcl-xL expression.
Apoptosis ; drug effects ; physiology ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Blotting, Western ; Cathepsin D ; metabolism ; Cytochromes c ; metabolism ; Fluorescent Antibody Technique ; Glucosamine ; pharmacology ; Humans ; K562 Cells ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism ; physiology

OBJECTIVETo investigate the role of reactive oxygen species (ROS) and ROS-caused mitochondrial transmembrane potential loss in sodium selenite-induced apoptosis in NB4 cells.

METHODSROS production was measured by ROS-specific probe DCFH-DA. Sodium selenite mitochondrial transmembrane potential loss was evaluated by flow cytometry with Rh123 staining. Protein levels of cytochrome C, Bid, Bcl-xl, and Bax were measured by Western blot using protein-specific antibodies. NB4 cells were pre-incubated by MnTmPy or BSO before selenite treatment to further confirm the effects of ROS on NB4 cells.

RESULTS20 micromol/L sodium selenite induced ROS production and mitochondrial transmembrane potential loss in NB4 cells time-dependently. Cytochrome C accumulated in cytoplasm after selenite treatment. Sodium selenite also downregulated Bcl-xl and activated Bax and Bid at protein level. Pretreatment with antioxidant MnTmPy almost fully abrogated the proapoptotic effect of sodium selenite prevented the cleavage of Bid protein and in turn the mitochondrail transmembrane potential loss. On the contrary, pretreatment with BSO intensified the mitochondrail transmembrane potential loss induced by sodium selenite.

CONCLUSIONSSodium selenite may induce apoptosis by inducing ROS production in NB4 cells, which leads to the downregulation of Bcl-xl, upregulation of Bax, and cleavage and activation of Bid. Bax and tBid then agregate on mitochondrial membrane, which in turn causes a decrease of mitochondrial transmembrane potential and release of cytochrome C into cytoplasm.

Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; biosynthesis ; Cell Line, Tumor ; Cytochromes c ; metabolism ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Reactive Oxygen Species ; metabolism ; Sodium Selenite ; pharmacology ; bcl-2-Associated X Protein ; biosynthesis ; bcl-X Protein ; biosynthesis

PURPOSE: A multi-subunit transcription factor NF-kappaB mediates the antiapoptotic signals in several cancer cell lines and it is activated in a broad range of human tumors. In this study, we investigated whether the expression levels of the NF-kappaB and the apoptosis inducing genes were related to the pathogenesis and clinical properties of human bladder tumor. MATERIALS AND METHODS: The expressions of NF-kappaB, BCL2-associated X protein (BAX), BCL2-associated death protein (BAD) and BH3-interacting domain death agonist protein (BID) were investigated by performing immunohistochemical staining on 133 archival bladder tissue paraffin blocks; these blocks included 122 transitional cell carcinomas of the urinary bladder and 11 normal bladder mucosae. RESULTS: The expression levels of NF-kappaB were significantly higher in the bladder tumors than those of the normal bladder mucosae (p=0.001). The expression levels of BAX in the superficial and low-grade (grade 1 and 2) bladder tumors were significantly enhanced more than those of the high-grade and invasive cases (p=0.042 and p=0.045, respectively), while the expression levels of BAD in the tumor tissues and low-grade tumors were significantly elevated compared with those of the normal mucosae and high grade tumor (p=0.007 and p=0.048, respectively). But the expressions of BID were not correlated with any pathologic and clinical properties. CONCLUSIONS: The expressions of the NF-kappaB and apoptosis inducing genes such as BAX and BAD are strongly associated with the pathogenesis and clinical properties of bladder tumor. (Korean J Urol 2007;48:483-488)
Apoptosis* ; bcl-2-Associated X Protein ; BH3 Interacting Domain Death Agonist Protein ; Carcinoma, Transitional Cell ; Cell Line ; Humans ; Mucous Membrane ; NF-kappa B* ; Paraffin ; Transcription Factors ; Urinary Bladder Neoplasms* ; Urinary Bladder*

A vast portion of human disease results when the process of apoptosis is defective. Disorders resulting from inappropriate cell death range from autoimmune and neurodegenerative conditions to heart disease. Conversely, prevention of apoptosis is the hallmark of cancer and confounds the efficacy of cancer therapeutics. In the search for optimal targets that would enable the control of apoptosis, members of the BCL-2 family of anti- and pro-apoptotic factors have figured prominently. Development of BCL-2 antisense approaches, small molecules, and BH3 peptidomimetics has met with both success and failure. Success-because BCL-2 proteins play essential roles in apoptosis. Failure-because single targets for drug development have limited scope. By examining the activity of the BCL-2 proteins in relation to the mitochondrial landscape and drawing attention to the significant mitochondrial membrane alterations that ensue during apoptosis, we demonstrate the need for a broader based multi-disciplinary approach for the design of novel apoptosis-modulating compounds in the treatment of human disease.
Apoptosis/*drug effects/physiology ; BH3 Interacting Domain Death Agonist Protein/physiology ; Drug Design ; Genes, bcl-2 ; Humans ; Mitochondria/physiology/ultrastructure ; Mitochondrial Membranes/*metabolism/physiology ; Multigene Family ; Proto-Oncogene Proteins c-bcl-2/*antagonists & inhibitors ; Signal Transduction

Apoptosis/*drug effects/physiology ; BH3 Interacting Domain Death Agonist Protein/physiology ; Drug Design ; Genes, bcl-2 ; Humans ; Mitochondria/physiology/ultrastructure ; Mitochondrial Membranes/*metabolism/physiology ; Multigene Family ; Proto-Oncogene Proteins c-bcl-2/*antagonists & inhibitors ; Signal Transduction

OBJECTIVEin septic mice, myocardial calpain was activated and induced caspase-3 activation, the association between calpain activation and apoptosis was explored in this experiment.

METHODSin in vivo model, adult C57 mice were injected with lipopolysaccharide (LPS, 4 mg/kg, i.p.) to induce sepsis. Myocardial calpain and caspase-3 activities, protein levels of calpain-1, calpain-2, calpastatin, Bcl-2 and Bid were detected by Western blot analysis and myocardial apoptosis was detected by TUNEL, myocardiac function was evaluated by Langendorff system. In in vitro model, adult rat cardiomyocytes were incubated with LPS (1 microg/ml) or co-incubated with calpain inhibitor-III (10 micromol/L), calpain activity, caspase-3 activity, protein levels of Bcl-2 and Bid, and cardiomyocyte apoptosis were detected.

RESULTSin septic mice, myocardial calpain and caspase-3 activity were increased up to 2.7- and 1.8-folds, respectively. Both calpain inhibitor-III and PD150606 significantly attenuated the increase of caspase-3 activity. Myocardial protein levels of calpain-1, calpain-2, calpastatin, Bcl-2 and Bid were similar between control and septic mice, and no cleavage of both Bcl-2 and Bid was found in septic mice. Calpain inhibitor-III significantly improved myocardial function in septic mice. In in vitro model, calpain and caspase-3 activities were increased after 4 h LPS treatment, co-treatment with calpain inhibitor-III prevented caspase-3 activity increase, protein Bcl-2 and Bid were similar between normal cardiomyocytes and LPS-treated cardiomyocytes. Cardiomyocyte apoptosis was similar in in vivo and in vitro septic models.

CONCLUSIONmyocardial calpain activity is increased in LPS induced septic mice, subsequent caspase-3 activation may contribute to myocardial dysfunction in septic mice without aggravating myocardial apoptosis and Bcl-2 and Bid are not involved on calpain induced caspase-3 activation in our model.

Animals ; Apoptosis ; BH3 Interacting Domain Death Agonist Protein ; metabolism ; Calcium ; metabolism ; Calpain ; metabolism ; Caspase 3 ; metabolism ; Male ; Membrane Proteins ; Mice ; Mice, Inbred C57BL ; Myocardium ; metabolism ; pathology ; Proto-Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; Sepsis ; metabolism

PURPOSE: This study demonstrated that apoptosis induced by mycophenolic acid (MPA) is mediated by mitochondrial membrane potential transition (MPT) changes in Jurkat cells. METHODS: Cell viability and MPT changes were measured by flow cytometry. Western blotting was performed to evaluate the expression of Bcl-2 family proteins, Bid, truncated Bid (tBid), cytochrome c, voltage dependent anion channel (VDAC), poly ADP-ribose polymerase (PARP), and protein kinase C-delta (PKC-delta). The catalytic activity of caspase-9 and -3 was also measured. RESULTS: Cell viability was decreased in time- and dose-dependent manners. Bcl-2 protein expression was decreased, but Bax protein expression was identified. A decreased Bcl-XL /Bcl-XS ratio was also noted. The expression of tBid protein also increased in a time-dependent manner in Jurkat cells treated with MPA. While normal MPT appeared as orange fluorescence, abnormal MPT corresponded to green fluorescence. Green fluorescence increased as orange decreased in the MPA-treated cells. Significantly increased concentrations of MPA induced the release of cytosolic cytochrome c. MPA also augmented the catalytic activity of caspase-9 and caspase-3 in Jurkat cells. Our findings demonstrated that MPA-induced apoptosis is mediated by MPT changes accompanied by decreased Bcl-XL expression and the appearance of tBid protein. The release of cytosolic cytochrome c from mitochondria and increased catalytic activity of caspase-9 and caspase-3 were observed in MPA-treated Jurkat cells. CONCLUSION: These results suggest that mitochondrial dysfunction caused by MPA induces human T lymphocyte apoptosis.
Adenosine Diphosphate Ribose ; Apoptosis ; bcl-2-Associated X Protein ; BH3 Interacting Domain Death Agonist Protein ; Blotting, Western ; Caspase 3 ; Caspase 9 ; Cell Survival ; Citrus sinensis ; Cytochromes c ; Cytosol ; Flow Cytometry ; Fluorescence ; Humans ; Jurkat Cells ; Lymphocytes ; Membrane Potential, Mitochondrial ; Mitochondria ; Mitochondrial Membranes ; Mycophenolic Acid ; Protein Kinase C-delta ; Proteins