PURPOSE: We investigated the effect of ceramide on keratocyte apoptosis and pathway of ceramide-induced keratocyte apoptosis. METHODS: Cultured Newzealand White Rabbit keratocytes were exposed to various concentrations of ceramide type II, VI and phytoceramide type II, VI. LDH level was measured for the evaluation of time and concentration related apoptosis. Keratocytes were preincubated in various concentrations of CPP32-like protease inhibitor (Z-VAD-FMK, diffuse caspase inhibitor), specific caspase-8 inhibitor (IETD-CHO) and specific caspase-9 inhibitor (Z-LEHD-FMK), then were exposed to 20 micro M of 4 types of ceramide. Cytochome C immune stainining was done after exposure of keratocyte to 4 types of ceramide. RESULTS: The lower effective dose of 4 types of ceramide was 20 micro M. Apoptosis of keratocytes was dependent on ceramide exposure time. Ceramide induced keratocyte apoptosis was inhibited by CPP32-like protease inhibitor, specific caspase-8 inhibitor and specific caspase-9 inhibitor. Apoptotic keratocytes induced by ceramide were immune-stained with cytochrome C antibody. CONCLUSIONS: Ceramide induced apoptosis in cultured corneal keratocytes. This apoptosis developed according caspase cascade, especially via mitochondria.
Apoptosis* ; Caspase 8 ; Caspase 9 ; Corneal Keratocytes ; Cytochromes c ; Mitochondria ; Protease Inhibitors

PURPOSE: To evaluate the effect of variable ceramides on the apoptosis of corneal endothelial cell and then, if ceramide induce the apoptosis in endothelial cells, via which pathway apoptosis occur. METHODS: Corneal endothelial cells were isolated from fresh rabbit cornea and cultured. Cultured corneal endothelial cells were exposed to 10, 20, 40 and 80 micro M of ceramide type II, VI and phytoceramide type II, VI. And then, apoptosis was evaluated with Hoechst staining and flow cytometric analysis with Annexin V for evaluation of apoptotic response. Corneal endothelial cells were preincubated in various concentrations of CPP32-like protease inhibitor (Z-VAD-FMK(R)), specific caspase-8 inhibitor(IETD-CHO(R)) and specific caspase-9 inhibitor (Z-LEHD-FMK(R)), then treated with 20 M of 4 types of ceramide. 12 hours later, LDH assay was done. Cytochrome c immunostaining was done after exposure to 4 types of ceramide. RESULTS: Shrinkage of cytoplasm, formation of apoptotic bodies, and nuclear fragmentation were observed on Hoechst staining. In flow cytometric analysis, early apoptotic responses were identified. Apoptotic response increased significantly at the concentration of 10M and more 12 hours later. CPP32-like protease inhibitor, caspase-8, 9 inhibitor reduced the LDH activity. Apoptotic endothelial cells induced by ceramide were stained with cytochrome c antibody. CONCLUSIONS: Ceramide induced apoptosis in cultured corneal endothelial cells. This apoptosis developed via caspase and mitochondrial pathway.
Annexin A5 ; Apoptosis* ; Caspase 8 ; Caspase 9 ; Ceramides ; Cornea ; Cytochromes c ; Cytoplasm ; Endothelial Cells* ; Protease Inhibitors

PURPOSE: The purpose of this study was to determine if ceramide, which is known as secondary messenger of programmed cell death (apoptosis), can cause apoptosis in lens epithelial cell (LEC) and if so, to identify the pathway by which apoptosis occurs. METHODS: After LECs were exposed to various concentrations of ceramide and phytoceramide, we evaluated the resulting apoptosis response using the Hoechst-EthD stain and Annexin stain. To search for the apoptosis pathway, LECs were preincubated in various concentrations of CPP32-like protease inhibitor, specific caspase-8 inhibitor, and specific caspase-9 inhibitor, then treated with ceramide and phytoceramide. We performed LDH assay 12 hours later. Cytochrome c immunostaining was done after exposure to the ceramide and phytoceramide. RESULTS: All kinds of ceramide induced time and concentration dependent apoptosis in LEC. Caspase 8 inhibitor and caspase 9 inhibitor reduced the apoptosis in ceramide VI, phytoceramide II, and phytoceramide VI. In all ceramides, cytochrome c staining was positive. CONCLUSIONS: Ceramide and phytoceramide can cause apoptosis in LEC. Ceramide and phytoceramide may be used to prevent the posterior capsular opacity after cataract surgery.
Apoptosis* ; Caspase 8 ; Caspase 9 ; Cataract ; Cell Death ; Ceramides ; Cytochromes c ; Epithelial Cells* ; Protease Inhibitors

OBJECTIVETo study the effect of ginsenoside on apoptosis of human leukemia-60 (HL-60) cells and its mechanism.

METHODSMTT cytotoxicity assay was used to determine the growth inhibition activity of ginsenoside (100, 50, 25, 12.5, 6.25, 3.125 and 1.5625 μmol/L) on HL-60 cells. The apoptosis of HL-60 cells after treatment with ginsenoside (0,5,10 and 20 μmol/L) was determined by Annexin V-FITC/PI staining and flow cytometry. The cleavage of total proteins by caspase-8, caspase-9 and caspase-3 was evaluated by Western blot. The cleavage of caspase-3 protein was detected by Western blot after treatment with 10 μmol/L ginsenoside and caspase-8 and 9 inhibitors.

RESULTSGinsenoside had potent cytotoxicity on HL-60 cells, with an IC50 value of 7.3±1.2 μmol/L. After treatment with ginsenoside (0, 5, 10 and 20 μmol/L) for 48 hours, the apoptotic rate displayed a dose dependency, as shown by flow cytometry, with significant differences between the groups (F=12.67, P<0.01). Western blot showed that there were caspase-9 and caspase-3 cleavage bands, but without caspase-8 cleavage band. The specific inhibitor of caspase-9 Z-LEHD-FMK could block the caspase-3 cleavage induced by 10 μmol/L ginsenoside, but the specific inhibitor of caspase-8 Z-IETD-FMK did not have this effect.

CONCLUSIONSGinsenoside can induce apoptosis of HL-60 cells, which may be related to a mitochondria-dependent pathway.

Apoptosis ; drug effects ; Caspase 9 ; physiology ; Caspase Inhibitors ; pharmacology ; Ginsenosides ; pharmacology ; HL-60 Cells ; Humans

PURPOSE: NS398, a selective COX-2 inhibitor, is known to inhibit the growth of COX-2 expressing hepatocellular carcinoma cells. The present study investigated whether the cytotoxic effect of NS398 was COX-2 dependent and whether caspases were involved in NS398-induced apoptosis in hepatocellular carcinoma cells. MATERIALS AND METHODS: The expressions of COX-2 in SNU 423 and SNU 449 hepatocellular carcinoma cell lines were examined using RT-PCR and Western blot. The cytotoxic effect of NS398 was measured using MTT in the presence or absence of caspase inhibitors. The distribution of the cell cycle and extent of apoptosis were analyzed using flow cytometry and a Cell Death Elisa kit, respectively. RESULTS: The expression of COX-2 was observed in SNU423 cells, but not in SNU 449 cells. NS398 treatment resulted in both dose-and time-dependent growth inhibitions, with increases in apoptotic cells in both cell lines. Treatment with the pan-caspase inhibitor, z-VAD- fmk, or the caspase-3 inhibitor, Ac-DMQD-CHO, showed no attenuation of the cytotoxic effect of NS398 in either cell line. CONCLUSIONS: This study demonstrated that the cytotoxic effect of NS398 was independent of COX-2 expression. Caspases were also shown not to be involved in NS398-induced apoptosis in either SNU 423 or SNU 449 Korean HCC cell lines. Our data suggests the feasibility of preventing hepatocellular carcinoma with the use of COX-2 inhibitors needs to be carefully evaluated.
Apoptosis* ; Blotting, Western ; Carcinoma, Hepatocellular* ; Caspase 3 ; Caspase Inhibitors ; Caspases ; Cell Cycle ; Cell Death ; Cell Line* ; Cyclooxygenase 2 ; Cyclooxygenase 2 Inhibitors ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry

BACKGROUND/AIMS: Peroxisome proliferator-activated receptor (PPAR)-gamma ligand is known to inhibit the growth of several kinds of cancer cells, yet its effect on cholangiocarcinoma is indecisive. We investigated the effect of an endogenous ligand of PPAR-gamma, 15-deoxy-delta (12,14)-prostaglandin J2 (15-deoxy-PGJ2) on cholangiocarcinoma cells that were established from intrahepatic cholangiocarcinoma tissue of Korean patients. METHODS: Four cholangiocarcinoma cell lines, Cho-CK, Choi-CK, JCK and SCK, were studied. The mRNA expression of PPAR-gamma, bcl-2, and bax were examined by RT-PCR. Cell viability was determined by MTT assay. The cell cycle was analyzed by flow cytometry, and apoptosis by cell death detection ELISA kit. Caspase activity was measured by colorimetric assay. The effect of caspase inhibitors on 15-deoxy-PGJ2-induced apoptosis was determined by measuring cell viability using the MTT assay. RESULTS: PPAR-gamma mRNA was expressed in all cholangiocarcinoma cells. 15-deoxy-PGJ2 inhibited proliferation of all cells in a dose- and time-dependent manner. All cells treated with 15-deoxy-PGJ2 showed increased dose-dependent apoptosis. Caspase 3 was activated in all cells and caspase 9 was activated in all but JCK cells after 15-deoxy-PGJ2 treatment. Caspase 8 activity showed no significant change. The pan-caspase inhibitor, Z-VAD-FMK, and the caspase-3 inhibitor, Z-DEVD-FMK, blocked 15-deoxy-PGJ2-induced apoptosis in all cells dose-dependently. The expression of bcl-2 was decreased in Cho-CK, Choi-CK and SCK cells, and bax expression was not changed significantly after 15-deoxy-PGJ2 treatment. CONCLUSIONS: PPAR-gamma mRNA was expressed in all Korean cholangiocarcinoma cells. Our data suggest that 15-deoxy-PGJ2 exerts an antineoplastic effect against cholangiocarcinoma cells by inducing apoptosis through caspase activation.
Amino Acid Chloromethyl Ketones ; Apoptosis ; Caspase 3 ; Caspase 8 ; Caspase 9 ; Caspase Inhibitors ; Cell Cycle ; Cell Death ; Cell Line ; Cell Survival ; Cholangiocarcinoma ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Liver Neoplasms ; Oligopeptides ; Peroxisomes ; PPAR gamma ; Prostaglandin D2 ; RNA, Messenger

PURPOSE: The purpose of this study was to evaluate the effect of mitomycin C on rabbit keratocytes for their potential to modulate corneal stromal wound healing. We also investigated the pathway on which the modulation occurs. METHODS: Keratocytes were isolated from New Zealand White Rabbits and cultured. We used Hoechst stain and flowcytometric analysis with Annexin V to identify the kind of response that mitomycin C induced from the keratocytes. After cultured keratocytes were exposed to 0.005%, 0.01%, 0.02%, 0.04%, and 0.06% mitomycin C, we evaluated the response with LDH assay. Next, after exposing the keratocytes to 0.01% mitomycin C, we evaluated the responses with LDH assay at 6, 12, and 24 hours. Keratocytes were preincubated in various concentrations of CPP32-like protease inhibitor (Z-VAD-FMK(R)), specific caspase-8 inhibitor (Z-IETD-FMK(R)), and specific caspase-9 inhibitor (Z-LEHD-FMK(R)), then treated with 0.01% mitomycin C. Twelve hours later, an LDH assay was performed. Cytochrome C immunostain was done after exposure to 0.01% mitomycin C. RESULTS: We observed shrinkage of cytoplasm, formation of apoptotic bodies, and nuclear fragmentation on Hoechst staining. In flowcytometric analysis, the cells showed apoptotic change. LDH activities increased significantly at a concentration of 0.005% and greater and were time-dependent until 24 hours. CPP32-like protease inhibitor decreased the LDH activity, but there was no statistical significance. Specific caspase-8 and -9 inhibitors significantly reduced the LDH activities that were induced by mitomycin C. The keratocytes which had been pretreated with mitomycin C were stained with cytochrome C antibody. CONCLUSIONS: Mitomycin C induces apoptosis, rather than necrosis, in cultured corneal keratocytes. This apoptosis occurs via the caspase pathway, and is especially related to the mitochondrial pathway, and caspases 8, and 9.
Annexin A5 ; Apoptosis* ; Caspase 8 ; Caspase 9 ; Caspases ; Corneal Keratocytes ; Cytochromes c ; Cytoplasm ; Mitochondria ; Mitomycin* ; Necrosis ; Protease Inhibitors ; Rabbits ; Wound Healing

Emphysema is characterized by air space enlarge?ment and alveolar destruction. The mechanism responsible for the development of emphysema was thought to be protease/antiprotease imbalance and oxidative stress. A very recent study shows that alveolar cell apoptosis causes lung destruction and emphysematous changes. Thus, this study was per?formed to support the evidence for the role of apoptosis in the development of emphysema by characterizing cigarette smoke extract (CSE)-induced apoptosis in A549 (type II pneumocyte) lung epithelial cells. CSE induced apoptosis at low concentration (10% or less) and both apoptosis and necrosis at high concentration (20%). Apoptosis was demonstrated by DNA fragmentation using FACScan for subG1 fraction. Discrimination between apoptosis and necrosis was done by morphologic analysis using fluorescent microscopy with Hoecst 33342/propium iodide double staing and electron microscopy. Cy?tochrome c release was confirmed by using immuno?fluorescence with monoclonal anti-cytochrome c antibody. However, CSE-induced cell death did not show the activation of caspase 3 and was not blocked by caspase inhibitors. This suggests that CSE-induced apoptosis might be caspase-independent apoptosis. CSE-induced cell death was near com?pletely blocked by N-acetylcystein and bcl-2 over?expression protected CSE-induced cell death. This results suggests that CSE might induce apoptosis through intracellular oxidative stress. CSE also activated p53 and functional knock-out of p53 using stable overexpression of HPV-E6 protein inhibited CSE-induced cell death. The characterization of CSE-induced cell death in lung epithelial cells could support the role of lung cell apoptosis in the patho?genesis of emphysema.
Apoptosis ; Caspase 3 ; Caspase Inhibitors ; Cell Death* ; Discrimination (Psychology) ; DNA Fragmentation ; Emphysema ; Epithelial Cells* ; Lung* ; Microscopy ; Microscopy, Electron ; Necrosis ; Oxidative Stress ; Smoke* ; Tobacco Products*

BACKGROUND: Numerous studies demonstrated that genistein induced the decrease of proliferation and apoptosis in a variety of cells. However, there is no report about the effect of genistein on proliferation and demise of mast cells. OBJECTIVE: This study was conducted to investigate genistein-induced aoptosis of mast cells as it pertains to both its basic drug mechanism and the potential therapeutics of the pathologic conditions accompanying mast cell proliferation. METHODS: p815 murine mastcytoma cell line was used to assess the effects of genistein treatment including viability and proliferation, morphlolgic study, DNA electrophoresis, the effect of caspase inhibitor, western blotting, and mitochondrial event. RESULTS: Genistein indeced many apoptotic manifestations as evidenced by changes in cell morphology, generation of DNA fragmentation, activation of caspase 3, and DNA hypoploidy. The reduction of mitochondrial membrae potential and the release of cytochrome c to cytosol were also demonstrated. However, reduction of mitochondrial membrane potential and cytochrome c release were not prevented by caspase inhibitors zVAD-fmk and BocD.fmk, or PTP(permeability transition pore) blockers such as bongkrekic acid and cyclosporin A. CONCLUSIONS: This in vitro study suggests that pathologic increases in mast cell number possibly be regulated in vivo by therapeutic strategy enhancing apoptosis by treatment of genistein.
Apoptosis* ; Blotting, Western ; Bongkrekic Acid ; Caspase 3 ; Caspase Inhibitors ; Cell Line ; Cyclosporine ; Cytochromes c ; Cytosol ; DNA ; DNA Fragmentation ; Electrophoresis ; Genistein ; Mast Cells ; Mastocytoma* ; Membrane Potential, Mitochondrial

OBJECTIVETo design hammerhead ribozymes against mouse caspase-7 and to study their expression and cleavage activity in vitro.

METHODSThe secondary structures of ribozyme and caspase-7 genes were analyzed and simulated by computer. Ribozymes DNA sequences were synthesized by automatic synthetic apparatus. Caspase-7 DNA sequence was acquired by reverse transcription PCR. Ribozymes and caspase-7 DNA sequences were separately cloned into pBSKneo U6 and pGEM-T vectors. Ribozymes and caspase-7 mRNA were obtained by transcription in vitro, and ribozymes cleavage activity was identified by cleavage experiment in vitro.

RESULTSTwo ribozymes named Rz333 and Rz394 targeting 333 and 394 sites in caspase-7 mRNA were designed by computer software, and their DNA sequences were synthesized. The expression vector of caspase-7 and plasmids containing Rz333 and Rz394 were reconstructed successfully. Ribozymes and caspase-7 mRNA were expressed by in vitro transcription. In vitro cleavage experiments showed that Rz333 cleaved caspase-7 mRNA and produced 243nt and 744nt segments. The cleavage efficiency is 67.98%, while Rz394 cannot cleave caspase-7 mRNA.

CONCLUSIONSRz333 can site-specifically cleave caspase-7 mRNA.

Animals ; Base Sequence ; Caspase 7 ; Caspase Inhibitors ; Caspases ; genetics ; Cloning, Molecular ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; RNA, Catalytic ; biosynthesis ; genetics ; metabolism ; RNA, Messenger ; biosynthesis ; genetics