Effect of Quercetin on the Proliferation and Mitochondrial Transmembrane Potential of CBRH-7919 Cells

[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy （APA）; morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential （△ψm） intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential（△ψm） intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.

Effect of rhTNF-α on Mitochondrial Transmembrane Potential and Motility of Human Sperm in vitro by Flow Cytometry and Computer Aided of Semen Analysis

To evaluate effect of recombined human tumor necrosis factor （rhTNF- α） on mitochondrial transmembrane potential and motility of human sperm in vitro Methods Semen samples for study were obtained from 40 health men （average age 26 ± 1.2 years） with normal semen analysis. Sperm suspension with computer aided of semen analysis （CASA） technique; 2） were stained in the presence of 10 μg/ml Rh123 and PI, mitochondrial transmembrane potential of those was analyzed by flow cytometry （FCM）. Results Significant differences were found between experimental groups and control groups on viability, straight line velocity, curvilinear velocity, average path velocity, progressive motility of human sperm and number of sperm with normal mitochondrial transmembrane potential （P〈0.01） expect final concentration 30 pg/ml group （P〉0. 05）. Sperm motility lowed with increasing rhTNF-α concentration and incubating time （P〈0. 01）. Number of sperm with normal mitochondrial transmembrane potential decreased with increasing rhTNF-α concentration and incubating time （P〈0.01）. Conclusion rh TNF-α can decrease human sperm motility function in vitro, which can interfere the function of human sperm mitochondrial transmembrane potential and may inhibit sperm mitochondrial enzymatic activities.

Effect of [Ca^(2+)]_i and Neuronal Mitochondria Transmembrane Potentials in Hippocampus of Murine Cytomegalovirus Infected Mice

To explore the effect of [-Ca^2＋]i and neuronal mitochondria transmembrane potentials in hippocampus of murine cytomegalovirus （MCMV） infected mice, newborn Balb/c mice were randomly divided into two groups： a virus inoculated group and a control group. After 56 days, single cell of hippocampus was isolated, and mitochondria transmembrane potentials and the intracellular free calcium level [-Ca^2＋]i in hippocampus were measured by means of flow cytometry （FCM）. Compared with the control group, the mitochondria transmembrane potentials was decreased （P〈0. 01 ） and the intracellular free calcium level [-Ca^2＋]i was increased （P〈0. 01） in inoculated group. The dysfunction of [-Ca^2＋]i and mitochondria transmembrane potentials in hippocampus may play an important role in the functional disorders in CMV-infected CNS.

EFFECT OF DESTRUCTION OF NTS AND PVN ON NEIGUAN (PC6)- ELECTROACUPUNCTURE-I NDUCED IMPROVEMENT OF ISCHEMIC MYOCARDIAL CELLULAR MEMBRANE POTENTIALS IN RABBITS

Objective: To observe the influence of electrolytic destruction of nucleus soli tary tract (NTS) and hypothalamic paraventricular nucleus (PVN) on the effect of electroacupuncture (EA) in improving ischemic myocardia cellular transmembrane action potential (TMAP). Methods: 38 Japanese breed big-ear wh ite rabbits (ane sthetized with 20% Urethane, 4 mL/kg) were randomly divided into acute myocardia l ischemia (AMI) group (n=8), PVN destruction group ( n=12) and PVN+NTS destructio n group (n=18). AMI model was established by occlusion of the descending anterio r branch (DAB) of the coronary artery. TMAP of myocytes was recorded by using a glass microelectrode which was fixed to a suspending spring silver wire. Bilater al "Neiguan"(PC 6) in all the 3 groups were punctured and stimulated electri call y by using parameters of continuous waves, frequency of 7 Hz, intensity of 6 mA a nd duration of 30 minutes. Results: After AMI, ECG-ST elevated significantly whil e APA lowered, APD50 and APD90 shortened clearly in comparison with those of pre -AMI in the 3 groups. Compared with AMI group, ECG-ST values of PVN destructi on group and PVN+NTS destruction group were significantly higher (P <0.05～0.01), whi le APA, APD50 and APD90 all significantly lower in all the recording time course s(P<0.05). The facts displayed that electrolytic destru ction of PVN and PVN+NT S could produce ischemic myocardial injury and reduce the protective effect of E A on ischemic myocardial cells. Comparison between PVN destruction and PVN+NTS g roups showed that all the 4 indexes of the later group were evidently worse than those of the former group (P<0.05), suggesting after des truction of these two n uclei, the effect of EA was worsened further. Conclusion: Electrolytic destru ction of PVN and NTS weakens the protective effect of EA on ischemic myocardial cells, both NTS and PVN take part in the effect of EA of "Neiguan"(PC 6) Point i n improving ischemic myocardium.

Restoration of Mitochondrial Structure and Function within Helicobacter pylori VacA Intoxicated Cells

The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has been reported to alter overall cellular metabolism, there is little known about the consequences of extended exposure to the toxin. Here, we describe studies to address this gap in knowledge, which have revealed that mitochondrial dysfunction and fragmentation are followed by a time-dependent recovery of mitochondrial structure, mitochondrial transmembrane potential, and cellular ATP levels. Cells exposed to VacA also initially demonstrated a reduction in oxidative phosphorylation, as well as increase in compensatory aerobic glycolysis. These metabolic alterations were reversed in cells with limited toxin exposure, congruent with the recovery of mitochondrial transmembrane potential and the absence of cytochrome c release from the mitochondria. Taken together, these results are consistent with a model that mitochondrial structure and function are restored in VacA-intoxicated cells.

Ethanol induced mitochondria injury and permeability transition pore opening: Role of mitochondria in alcoholic liver disease

AIM: To observe changes of mitochondria and investigate the effect of ethanol on mitochondrial perme- ability transition pore (PTP), mitochondrial membrane potential (MMP, ΔΨm) and intracellular calcium concentration in hepatocytes by establishing an animal model of alcoholic liver disease (ALD). METHODS: Fourty adult male Wistar rats were randomly divided into two groups, the model group (20) was administered alcohol intragastrically plus an Oliver oil diet to establish an ALD model, and the control group (20) was given an equal amount of normal saline. The ultramicrostructural changes of mitochondria were observed under electron microscopy. Mitochondria of liver was extracted, and patency of PTP, mitochondrial membrane potential (ΔΨm), mitochondrial mass and intracellular calcium concentration of isolated hepacytes were detected by flow cytometry using rhodamine123 (Rh123), Nonyl-Acridine Orange and calcium fluorescent probe Fluo-3/AM, respectively. RESULTS: Membrane and cristae were broken or disappeared in mitochondria in different shapes under electron microscopy. Some mitochondria showed U shape or megamitochondrion. In the model group, liver mitochondria PTP was broken, and mitochondria swelled, the absorbance at 450 nm, A540 decreased (0.0136 ± 0.0025 vs 0.0321 ± 0.0013, model vs control, P < 0.01); mitochondria transmembrane potential (239.4638 ± 12.7263 vs 377.5850 ± 16.8119, P < 0.01) was lowered; mitochondrial mass (17.4350 ± 1.9880 vs 31.6738 ± 3.4930, P < 0.01); and [Ca2+]i was increased in liver cells (7.0020 ± 0.5008 vs 10.2050 ± 0.4701, P < 0.01).CONCLUSION: Chronic alcohol intake might lead to broken mitochondria PTP, decreased mitochondria membrane potential and injury, and elevated intracellular Ca2+ production. Ethanol-induced chondriosome injury may be an important mechanism of alcoholic diseases.

Scutellaria barbate extract induces apoptosis of hepatoma H22 cells via the mitochondrial pathway involving caspase-3

AIM： To study the growth inhibitory and apoptotic effects of Scutellaria barbata D.Don （S. barbata） and to determine the underlying mechanism of its antiturnor activity in mouse liver cancer cell line H22.METHODS： Proliferation of H22 cells was examined by MTT assay. Cellular morphology of PC-2 cells was observed under fluorescence microscope and transmission electron microscope （EM）. Mitochondrial transmembrane potential was determined under laser scanning confocal microscope （LSCM） with rhodamine 123 staining. Flow cytometry was performed to analyze the cell cycle of H22 cells with propidium iodide staining. Protein level of cytochrome C and caspase-3 was measured by semi-quantitive RT-PCR and Western blot analysis. Activity of caspase-3 enzyme was measured by spectrofluorometrv.RESULTS： M-I-I- assay showed that extracts from S. barbata （ESB） could inhibit the proliferation of H22 cells in a time-dependent manner. Among the various phasesof cell cycle, the percentage of cells in S phase was significantly decreased, while the percentage of cells in G1 phase was increased. Flow cytometry assay also showed that ESB had a positive effect on apoptosis. Typical apoptotic morphologies such as condensation and fragmentation of nuclei and blebbing membrane of apoptotic cells could be observed under transmission electron microscope and fluorescence microscope. To further investige the molecular mechanism behind ESB-induced apoptosis, ESB-treated cells rapidly lost their mitochondrial transmembrane potential, released mitochondrial cytochrome C into cytosol, and induced caspase-3 activity in a dose-dependent manner. CONCLUSION： ESB can effectively inhibit the proliferation and induce apoptosis of H22 cells involving loss of mitochondrial transmembrane potential, release of cytochrome C, and activation of caspase-3.

Puerarin prevents high glucose-induced apoptosis of Schwann cells by inhibiting oxidative stress

Oxidative stress may be the unifying factor for the injury caused by hyperglycemia in diabetic peripheral neuropathy. Puerarin is the major isoflavonoid derived from Radix puerariae and has been shown to be effective in increasing superoxide dismutase activity. This study sought to investigate the neuroprotective effect of puerarin on high glucose-induced oxidative stress and Schwann cell apoptosis in vitro. Intracellular reactive oxygen radicals and mitochondrial transmembrane potential were detected by flow cytometry analysis. Apoptosis was confirmed by TUNEL and oxidative stress was monitored using an enzyme-linked immunosorbent assay for the DNA marker 8-hydroxy-2-deoxyguanosine. The expression levels of bax and bcl-2 were analyzed by quantitative real-time reverse transcriptase-PCR, while protein expression of cleaved caspase-3 and -9 were analyzed by means of western blotting. Results suggested that puerarin treatment inhibited high glucose-induced oxidative stress, mitochondrial depolarization and apoptosis in a dose-dependent manner. Furthermore, puerarin treatment downregulated Bax expression, upregulated bcl-2 expression and attenuated the activation of caspase-3 and -9. Overall, our results indicated that puerarin antagonized high glucose-induced oxidative stress and apoptosis in Schwann cells.

Effects of abnormal excitation on the dynamics of spiral waves

The effect of physiological and pathological abnormal excitation of a myocyte on the spiral waves is investigated based on the cellular automaton model. When the excitability of the medium is high enough, the physiological abnormal excitation causes the spiral wave to meander irregularly and slowly. When the excitability of the medium is low enough, the physiological abnormal excitation leads to a new stable spiral wave. On the other hand, the pathological abnormal excitation destroys the spiral wave and resultsin the spatiotemporal chaos, which agrees with the clinical conclusion that the early after depolarization is the pro-arrhythmic mechanism of some anti-arrhythmic drugs. The mechanisms underlying these phenomena are analyzed.

How Does the Slow Injection of a Medicine under the Influence of a Magnetic Field Affects the Spreading of Medical Substances

The problem of excitation and the propagation of a nerve impulse by an axon (nerve fiber) for the case of a noninstantaneous function is studied. The application of no instantaneous step function of the Heaviside type takes into account the time of delay. This generalizes the problem of the propagation of axon excitation to the case of an input impulse function’s noninstantaneous action with some increasing excitation. An exact analytical solution to the problem is constructed based on the Laplace integral transform and Ephros theorem. The propagation of the transmembrane potential was studied, in response to the switching on and off, for impulse of a constant current pulse delivered intracellularly at different points in time. The time analysis of excitation propagation along axon at different distances from the excitation point was performed.

Mitochondria Play a Role in the Development of Non-Apoptotic Programmed Cell Death of Neutrophils Induced by ONO-AE-248

We previously reported that ONO-AE-248, a selective EP3 receptor agonist, has been shown to cause neutrophil death without the typical features of apoptosis and necrosis. However, the mechanism of the neutrophil death is unclear. By using Western blotting, flow cytometry （FACS） and confocal laser scanning microscopy （CLSM）, we investigated the cellular signal transduction pathways of the neutrophil death. The research results showed that the neutrophil death induced by ONO-AE-248 did not show the morphologic changes of apoptosis and was not associated with the activity of caspase-3, caspase-8, and phosphorylation of p38-MAPK. However, impairment of mitochondria transmembrane potential has been found during the process of cell death. These findings suggested that ONO-AE-248 induced a non-apoptotic programmed cell death of neutrophils through partially mitochondria signaling transduction pathway. Cellular ＆ Molecular Immunology.

Protective paracrine effect of mesenchymal stem cells on cardiomyocytes

Objective： The aim of this study was to test the protective effect of mesenchymal stem cells （MSCs） on cardiomyocytes in vitro and to investigate the anti-apoptotic signaling pathway. Methods： MSCs from Sprague-Dawley （SD） rats were separated and cultured. MSC medium was collected from MSCs （DMEM） under hypoxia. Cultured cardiomyocytes from neonatal cultured in serum-free Dulbecco＇s modified eagle medium SD rats were exposed to hypoxia/reoxygenation （H/R） and treated with MSC medium. The apoptotic cardiomyocytes were stained with Annexin-V-fluorescein isothiocyanate （FITC）, Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL）. The mitochondrial transmembrane potential of cardiomyocytes was assessed using a fluorescence microscope. The expression of Bcl-2, Bax, cyto- chrome C, apoptosis-induced factor （AIF）, and caspase-3 was tested by Western blot analysis. Results： Our data demonstrated that MSC medium reduced H/R-induced cardiomyocyte apoptosis, increased the Bcl-2/Bax ratio, and reduced the release of cyto- chrome C and AIF from mitochondria into the cytosol. Conclusion： MSCs protected the cardiomyocytes from H/R-induced apoptosis through a mitochondrial pathway in a paracrine manner.

Pachymic acid, a novel compound for anti-rejection： effect in rats following cardiac allograft transplantation

Background Pachymic acid （PA）, a natural triterpenoid, is known to significantly reduce cell proliferation and induce apoptosis in vitro through initiation of mitochondria dysfunction. However, its effect on immune cells and anti-rejection following organ transplantation remains unknown. Methods In this study, we investigated PA as a treatment to control acute rejection occurred in rats which had accepted cardiac transplantation. We measured apoptosis of peripheral blood lymphocyte （PBLs）, and CD4^＋ lymphocyte, as well as the number of CD4^＋ and CD8^＋ lymphocytes and the effect of PA on acute rejection in rats 7 days after cardiac transplantation. Results PA treatment might decrease allograft rejection, protect PBLs from apoptosis, and reduce the percentage of CD8^＋ lymphocyte. PA neither regulated the number nor the apoptosis rate of CD4^＋ lymphocyte. Conclusions Our findings indicated that PA has an anti-apoptotic effect acting on PBLs through a novel mechanism involving stabilization of the PBLs mitochondrial transmembrane potential, an anti-rejection effect in rats after cardiac transplantation and an inhibiting effect to CD8^＋ lymphocyte.