OBJECTIVE: To examine the effects of ethyl pyruvate (EP) on mitochondrial dynamics and cell apoptosis in lipopolysaccharide (LPS)-induced human kidney-2 (HK-2) cells. METHODS: HK-2 cells were divided into three groups: HK-2 cells were challenged with LPS (800 μg/L) for 24 hours as LPS group, or LPS mixed with EP (0.25 mmol/L) for 24 hours as EP group. Cells were incubated with normal saline for 24 hours as control group. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and intracellular adenosine triphosphate (ATP) were detected by enzyme linked immunosorbent assay (ELISA). JC-1 staining and Annexin V-fluorescein isothiocyanate/propidium iodide (FITC/PI) assays were used to evaluate mitochondrial membrane potential and cell apoptosis, respectively. Western Blot was used to evaluate the protein expressions of mitochondrial dynamics, including death-associated protein kinase 2 (DAPK-2), mitofusin (Mfn-1 and Mfn-2), and apoptotic associated biomarkers, including caspase-3, caspase-9, Bcl-2, Bcl-xL, cytochrome C (Cyt C), and DNA repair enzyme poly ADP-ribose polymerase (PARP). RESULTS: Compared with the NC group, MDA, IL-6, TNF-α of LPS group were significantly increased, the expression of SOD, mitochondrial membrane potential and ATP level were significantly decreased, the expression of mitochondrial fission protein DAPK-2 was significantly increased, and mitochondrial fusion proteins Mfn-1 and Mfn-2 were significantly decreased, cell apoptosis and apoptotic protein caspase-3, caspase-9 and Cyt C were increased, and anti-apoptotic protein Bcl-2, Bcl-xL, PARP were significantly decreased. Compared with the LPS group, the oxidative activities and inflammatory factors above were inhibited in EP group [MDA (μmol/L): 12.35±2.21 vs. 45.95±1.76, SOD (kU/L): 54.68±1.42 vs. 40.73±1.60, IL-6 (ng/L): 67.87±2.61 vs. 338.92±20.91, TNF-α (ng/L): 19.23±1.80 vs. 180.69±6.51], mitochondrial membrane potential and ATP level were significantly increased [mitochondrial membrane potential: (99.43±0.25)% vs. (69.40±0.75)%, ATP (×10⁶ RLU): 0.19±0.01 vs. 0.12±0.05], the expression of mitochondrial fission protein was significantly decreased (DAPK-2/β-actin: 0.03±0.01 vs. 0.61±0.02), mitochondrial fusion proteins were significantly increased (Mfn-1/β-actin: 0.43±0.04 vs. 0.17±0.01, Mfn-2/β-actin: 0.201±0.004 vs. 0.001±0.001), percentage of cell apoptosis was significantly decreased [(5.25±0.17)% vs. (34.42±0.64)%], the expressions of apoptotic proteins were significantly decreased (caspase-3/β-actin: 0.25±0.15 vs. 1.76±0.01, caspase-9/β-actin: 0.09±0.02 vs. 1.52±0.12, Cyt C/β-actin: 0.001±0.001 vs. 0.350±0.030), and the expressions of anti-apoptotic proteins and PARP were significantly increased (Bcl-2/β-actin: 0.500±0.010 vs. 0.009±0.004, Bcl-xL/β-actin: 0.550±0.010 vs. 0.009±0.001, PARP/β-actin: 0.94±0.01 vs. 0.16±0.13), with statistically significant differences (all P < 0.05). CONCLUSIONS There are enhanced mitochondrial fission and diminished mitochondrial fusion in LPS-induced HK-2 cells. EP can protect mitochondria functions by regulate mitochondrial dynamics, and reducethe apoptosis of LPS-induced HK-2 cells.
Apoptosis ; Humans ; Kidney ; Lipopolysaccharides ; Mitochondrial Dynamics/drug effects* ; Protective Agents/pharmacology* ; Pyruvates/pharmacology*

OBJECTIVE: To investigate the anti-oxidative effect of ethyl pyruvate (EP) and taurine (TAU) on the quality of red blood cells stored at 4±2 ℃, hemolysis, energy metabolism and lipid peroxidation of the red blood cells in the preservation solution were studied at different intervals. METHODS: At 4±2 ℃, the deleukocyte red blood cells were stored in the citrate-phosphate-dextrosesaline-adenine-1 (CPDA-1) preservation (control group), preservation solution with EP (EP-AS), and TAU (TAU-AS) for long-term preservation. The enzyme-linked immunoassay and automatic blood cell analyzer were used to detect hemolysis and erythrocyte parameters. Adenine nucleoside triphosphate (ATP), glycerol 2,3-diphosphate (2,3-DPG) and malondialdehyde (MDA) kits were used to test the ATP, 2,3-DPG and MDA concentration. RESULTS: During the preservation, the rate of red blood cell hemolysis in EP-AS and TAU-AS groups were significantly lower than that in CPDA-1 group (P<0.01). The MCV of EP-AS group was increased with the preservation time (r=0.71), while the MCV of the TAU-AS group was significantly lower than that in the other two groups (P<0.05). The concentration of ATP and MDA in EP-AS and TAU-AS groups were significantly higher than that in CPDA-1 group at the 14th day (P<0.01). The concentrations of 2,3-DPG in the EP-AS and TAU-AS groups were significantly higher than that in the CPDA-1 group from the 7th day (P<0.01). CONCLUSION EP and TAU can significantly reduce the red blood cell hemolysis rate, inhibit the lipid peroxidation level of red blood cells, and improve the energy metabolism of red blood cells during storage. The mechanism of EP and TAU may be related to their antioxidation and membrane protection effect, so as to improve the red blood cell quality and extend the preservation time.
2,3-Diphosphoglycerate/metabolism* ; Adenine ; Adenosine Triphosphate/metabolism* ; Blood Preservation ; Citrates/pharmacology* ; Erythrocytes/metabolism* ; Glucose/pharmacology* ; Hemolysis ; Humans ; Pyruvates ; Taurine/pharmacology*

OBJECTIVETo study the effect of glycolysis inhibitor 3-bromopyruvate (3-BrPA) in inducing apoptosis of human breast carcinoma cells SK-BR-3 and the possible mechanism.

METHODSMTT assay was used to detect the growth inhibition induced by 3-BrPA in breast cancer cells SK-BR-3. The apoptotic cells were detected by flow cytometry with propidium iodide (PI). ATP levels in the cells were detected by ATP assay kit, and DHE fluorescent probe technique was used to determine superoxide anion levels; the mitochondrial membrane potential was assessed using JC-1 staining assay.

RESULTSMTT assay showed that the proliferation of SK-BR-3 cells was inhibited by 3-BrPA in a time- and concentration-dependent manner. Exposure to 80, 160, and 320 µmol·L(-1) 3-BrPA for 24 h resulted in cell apoptosis rates of 6.7%, 22.3%, and 79.6%, respectively, and the intracellular ATP levels of SK-BR-3 cells treated with 80, 160, 320 µmol·L(-1) 3-BrPA for 5 h were 87.7%, 60.6%, and 23.7% of the control levels. 3-BrPA at 160 µmol·L(-1) increased reactive oxygen levels and lowered mitochondrial membrane potential of SK-BR-3 cells.

CONCLUSION3-BrPA can inhibit cell proliferation, reduce the mitochondrial membrane potential and induce apoptosis in SK-BR-3 cells, the mechanism of which may involve a reduced ATP level by inhibiting glycolysis and increasing the reactive oxygen level in the cells.

Apoptosis ; drug effects ; Cell Line, Tumor ; Female ; Glycolysis ; Humans ; Membrane Potential, Mitochondrial ; drug effects ; Pyruvates ; pharmacology ; Reactive Oxygen Species ; metabolism

OBJECTIVE: The purpose of this study was to compare the antitumor effect and hepatotoxicity of an intraarterial delivery of low-dose and high-dose 3-bromopyruvate (3-BrPA) and those of a conventional Lipiodol-doxorubicin emulsion in a rabbit VX2 hepatoma model. MATERIALS AND METHODS: This experiment was approved by the animal care committee at our institution. VX2 carcinoma was implanted in the livers of 36 rabbits. Transcatheter intraarterial administration was performed using low dose 3-BrPA (25 mL in a 1 mM concentration, n = 10), high dose 3-BrPA (25 mL in a 5 mM concentration, n = 10) and Lipiodol-doxorubicin emulsion (1.6 mg doxorubicin/ 0.4 mL Lipiodol, n = 10), and six rabbits were treated with normal saline alone as a control group. One week later, the proportion of tumor necrosis was calculated based on histopathologic examination. The hepatotoxicity was evaluated by biochemical analysis. The differences between these groups were statistically assessed with using Mann-Whitney U tests and Kruskal-Wallis tests. RESULTS: The tumor necrosis rate was significantly higher in the high dose group (93% +/- 7.6 [mean +/- SD]) than that in the control group (48% +/- 21.7) (p = 0.0002), but the tumor necrosis rate was not significantly higher in the low dose group (62% +/- 20.0) (p = 0.2780). However, the tumor necrosis rate of the high dose group was significantly lower than that of the Lipiodol-doxorubicin treatment group (99% +/- 2.7) (p = 0.0015). The hepatotoxicity observed in the 3-BrPA groups was comparable to that of the Lipiodol-doxorubicin group. CONCLUSION: Even though intraarterial delivery of 3-BrPA shows a dose-related antitumor effect, single session treatment seems to have limited efficacy when compared with the conventional method.
Animals ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Doxorubicin/administration & dosage/pharmacology ; Infusions, Intra-Arterial ; Iodized Oil/administration & dosage/pharmacology ; Liver Neoplasms, Experimental/*drug therapy/radiography ; Pyruvates/administration & dosage/*pharmacology ; Rabbits ; Statistics, Nonparametric ; Tomography, X-Ray Computed

OBJECTIVETo investigate the effect of 3-bromopyruvate (3-BP) in sensitizing hepatocellular carcinoma cells to cisplatin-induced apoptosis and its possible mechanism.

METHODSThe growth inhibition of HepG2 and SMMC7721 cells following exposures to different concentrations of 3-BP and cisplatin was measured by MTT assay. The apoptosis of cells treated with 100 µmol/L 3-BP with or without 8 µmol/L cisplatin was assessed using flow cytometry with PI staining, and the activity of caspase-3 and intracellular ATP level were detected using commercial detection kits; the expression of XIAP and PARP was analyzed using Western blotting.

RESULTS3-BP produced obvious inhibitory effects on HepG2 and SMMC7721 cells at the concentrations of 50-400 µmol/L with IC50 values of 238.9∓13.9 µmol/L and 278.7∓11.7 µmol/L for a 48-h treatment, respectively. Cisplatin also inhibited the growth of HepG2 and SMMC7721 cells at the concentrations of 2-32 µmol/L, with IC50 values of 16.4∓0.9 µmol/L and 20.9∓1.8 µmol/L after a 48-h treatment, respectively. Treatment with 100 µmol/L 3-BP combined with 8 µmol/L cisplatin for 48 h resulted in a growth inhibition rate of (60.6∓2.2)% in HepG2 cells and (56.8∓2.3)% in SMMC7721 cells, which were significantly higher than those in cells treated with 3-BP or cisplatin alone. The combined treatment for 48 h induced an apoptotic rate of (51.1∓4.3)% in HepG2 cells and (46.5∓3.9)% in SMMC7721 cells, which were also markedly higher than those in cells with 3-BP or cisplatin treatment alone.

CONCLUSION3-BP can sensitize HepG2 and SMMC7721 cells to cisplatin-induced apoptosis possibly by causing intracellular ATP deficiency, down-regulating XIAP, and increasing caspase-3 activity.

Adenosine Triphosphate ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Caspase 3 ; metabolism ; Cisplatin ; pharmacology ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; Pyruvates ; pharmacology ; X-Linked Inhibitor of Apoptosis Protein ; metabolism

PURPOSE: Ethyl pyruvate has anti-inflammatory properties and protects organs from ischemia/reperfusion (I/R)-induced tissue injury. The aim of this study was to determine whether ethyl pyruvate decreases the inflammatory response after regional I/R injury and whether ethyl pyruvate protects against delayed regional I/R injury in an in vivo rat heart model after a 24 hours reperfusion. MATERIALS AND METHODS: Rats were randomized to receive lactated Ringer's solution or ethyl pyruvate dissolved in Ringer's solution, which was given by intraperitoneal injection 1 hour prior to ischemia. Rats were subjected to 30 min of ischemia followed by reperfusion of the left coronary artery territory. After a 2 hours reperfusion, nuclear factor kappaB, myocardial myeloperoxidase activity, and inflammatory cytokine levels were determined. After the 24 hours reperfusion, the hemodynamic function and myocardial infarct size were evaluated. RESULTS: At 2 hours after I/R injury, ethyl pyruvate attenuated I/R-induced nuclear factor kappaB translocation and reduced myeloperoxidase activity in myocardium. The plasma circulating levels of inflammatory cytokines decreased significantly in the ethyl pyruvate-treated group. At 24 hours after I/R injury, ethyl pyruvate significantly improved cardiac function and reduced infarct size after regional I/R injury. CONCLUSION: Ethyl pyruvate has the ability to inhibit neutrophil activation, inflammatory cytokine release, and nuclear factor kappaB translocation. Ethyl pyruvate is associated with a delayed myocardial protective effect after regional I/R injury in an in vivo rat heart model.
Animals ; Anti-Inflammatory Agents/*pharmacology ; Cell Nucleus/metabolism ; Cytoplasm/metabolism ; Heart/physiopathology ; Inflammation ; Male ; Myocardial Infarction/prevention & control ; Myocardium/*metabolism ; NF-kappa B/metabolism ; Peroxidase/metabolism ; Pyruvates/*pharmacology ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury/*drug therapy/*metabolism

OBJECTIVE: We wanted to investigate the feasibility of using FDG-PET for evaluating the antitumor effect of intraarterial administration of a hexokinase II inhibitor, 3-bromopyruvate (3-BrPA), in a rabbit VX2 liver tumor model. MATERIALS AND METHODS: VX2 carcinoma was grown in the livers of ten rabbits. Two weeks later, liver CT was performed to confirm appropriate tumor growth for the experiment. After tumor volume-matched grouping of the rabbits, transcatheter intraarterial administration of 3-BrPA was performed (1 mM and 5 mM in five animals each, respectively). FDG-PET scan was performed the day before, immediately after and a week after 3-BrPA administration. FDG uptake was semiquantified by measuring the standardized uptake value (SUV). A week after treatment, the experimental animals were sacrificed and the necrosis rates of the tumors were calculated based on the histopathology. RESULTS: The SUV of the VX2 tumors before treatment (3.87+/-1.51[mean+/-SD]) was significantly higher than that of nontumorous liver parenchyma (1.72+/-0.34) (p < 0.0001, Mann-Whitney U test). The SUV was significantly decreased immediately after 3-BrPA administration (2.05+/-1.21) (p = 0.002, Wilcoxon signed rank test). On the one-week follow up PET scan, the FDG uptake remained significantly lower (SUV 1.41+/-0.73) than that before treatment (p = 0.002), although three out of ten animals showed a slightly increasing tendency for the FDG uptake. The tumor necrosis rate ranged from 50.00% to 99.90% (85.48%+/-15.87). There was no significant correlation between the SUV or the SUV decrease rate and the tumor necrosis rate in that range. CONCLUSION: Even though FDG-PET cannot exactly reflect the tumor necrosis rate, FDG-PET is a useful modality for the early assessment of the antitumor effect of intraarterial administration of 3-BrPA in VX2 liver tumor.
Animals ; Disease Models, Animal ; Enzyme Inhibitors/*pharmacology ; Feasibility Studies ; Fluorodeoxyglucose F18 ; Infusions, Intra-Arterial ; Injections, Intra-Arterial ; Liver Neoplasms, Experimental/*drug therapy/pathology/*radionuclide imaging ; Necrosis ; *Positron-Emission Tomography ; Pyruvate Dehydrogenase Complex/antagonists & inhibitors ; Pyruvates/*pharmacology ; Rabbits ; Radiopharmaceuticals

In order to study the effects of ethyl pyruvate on cardiomyocyte apoptosis following ischemia/reperfusion (I/R) in vitro and the expression of Bcl-2 and Bax proteins, isolated rat hearts were perfused in a Langendorff model. Twenty-four rats were randomly divided into 3 groups (n=8 in each group): control group was perfused for 120 min. In the I/R group, after 30 min stabilization the injury was induced by 30 min global ischemia followed by 60 min reperfusion. Ethyl pyruvate (EP) group was set up with the same protocol as I/R group except that it was supplied with 2 mmol/L EP 15 min before ischemia and throughout reperfusion. Myocardial malonaldehyde (MDA) content was measured. Myocardial apoptotic index (AI) was tested by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. The expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax in cardiac myocytes was detected by immunohistochemistry. As compared with control group, the content of MDA, myocardial AI and the expression of Bcl-2, Bax proteins were increased significantly in I/R group, but the content of MDA, myocardial AI and the expression of Bax protein were decreased obviously and the expression of Bcl-2 protein was up-regulated in EP group (P<0.05). These results demonstrate that EP could inhibit apoptosis of cardiac myocytes possibly via alleviating oxidative stress, up-regulating Bcl-2 and down-regulating Bax proteins.
Apoptosis ; In Situ Nick-End Labeling ; Malondialdehyde/pharmacology ; Myocardium/*pathology ; Myocytes, Cardiac/cytology ; Oxidative Stress ; Proto-Oncogene Proteins c-bcl-2/*metabolism ; Pyruvates/*pharmacology ; Rats, Sprague-Dawley ; Reperfusion Injury ; Tissue Distribution ; bcl-2-Associated X Protein/*metabolism

OBJECTIVETo study the effect of glycolytic inhibitor 3-Bromopyruvate (3-BrPA) on the proliferation and apoptosis of mouse spleen lymphocytes and explore its mechanism.

METHODSAn one-way mixed lymphocyte culture (MLC) system was established, including BALB/c mouse spleen cells (H-2d) as stimulator and C57BL/6 mouse spleen cells (H-2b) as responder. With treatment of 3-BrPA at different concentrations (0-200 μmol/L), lymphocyte proliferation capacity was detected by the CCK-8 method, the expression of CD3, CD4, and CD8 by flow cytometry, and the concentrations of cytokine interleukin (IL)-4 and interferon (IFN)-γ in the supernatant by ELISA.

RESULTSAt a middle or high dose (over 20 μmol/L), 3-BrPA displayed a dose-dependent inhibitory effect on lymphocyte proliferation in the MLC system. The 50% inhibitory concentration (IC50) were 48.6, 41.2, and 41.9 μmol/L after 24, 36, and 48 h culture, respectively. With treatment of 50 μmol/L 3-BrPA, the IFN-γ level [(164.25 ± 20.14) ng/L] was significantly lower, compared with control [(277.61 ± 18.46) ng/L]. The IL-4 level [(31.06 ± 6.06) ng/L] was significantly higher, compared with control [(28.64 ± 3.97) ng/L]. Consequently, the IFN-γ/IL-4 ratio decreased significantly.

CONCLUSIONThese results indicate that 3-BrPA had a significant inhibitory effect on the proliferation of mouse spleen lymphocytes cultured in MLC system, accompanied with the Th2-biased secretion of cytokines.

Animals ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lymphocyte Culture Test, Mixed ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Pyruvates ; pharmacology ; Spleen ; cytology ; metabolism

The correlation between muscle glycogen content and physical performance in mice was evaluated by investigating whether an increase in glycogen content in skeletal muscle with insulin administration can improve the physical performance without other effects of exercise. Albino rats(group I) were divided into two groups, i.e., insulin and saline administered group. The former experimental group was treated with protamine zinc insulin(15U/kg/day) subcutaneously for two weeks to increase the content of the muscle glycogen and the latter control group with saline. Mice (group II) were also divided into insulin treated and control groups and both groups were subjected to running exercise on an animal treadmill up to point of exhaustion once every day. After two weeks of insulin treatment, the muscle glycogen content, the maximal running time and the maximal swimming time were measured in non-exercised group I. In group II, after 12 days of insulin and saline administration, the muscle glycogen content, the maximal running time, concentrations of lactate and pyruvate in the blood were measured before and after the maximal exhaustive running. The results were summarized as follows. In group I, the muscle glycogen content, the maximal running time and the maximal swimming time of the insulin administered group were significantly greater of the control groups. In group II, the maximal running time was significantly greater(P < 0.01) in the experimental group than of the control group, while the muscle glycogen content revealed no significant difference between the two groups. On the other hand, lactate concentration and lactate/pyruvate ratios in the blood were significantly lower in the experimental group than those of the control groups. From the above results, it may be concluded that the elevation of muscle glycogen content alone by insulin treatment without any previous physical training can improve physical performance of rats. And insulin was also found to improve physical performance even in experimental animals which had been subjected to a longterm of exercise.
Anaerobiosis/drug effects* ; Animal ; Blood Glucose/analysis ; Body Weight ; Exertion/drug effects* ; Glycogen/analysis* ; Injections, Subcutaneous* ; Insulin/administration & dosage ; Insulin/pharmacology* ; Lactates/blood ; Male ; Metabolism/drug effects* ; Mice ; Muscles/analysis* ; Pyruvates/blood ; Rats