Changes of plasma membrane ATPase activity, membrane potential and transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings with various salinities

The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kandelia candel were cultivated in sand with various salinities(0‰, 10‰, 20‰, 30‰, 40‰) for 60 d. Plasma membrane vesicles of high-purity in leaves and roots of A.marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within a certain range of salinity(A. marina and roots of K. candel: 0—30‰; leaves of K.candel: 0—20‰), the activity of ATPase increased with increasing salinity, while high salinity(above 30‰ or 20‰) inhibited ATPase activity. In comparison with A. marina, K. candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0—10‰(K. candel) or 0—20‰(A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely.

Effects of NaCl and Ca^2+on Membrane Potential of Epidermal Cells of Maize Roots

The effects of salt-stress on plants involve not only the water stress caused by low osmotic pressure, but also the toxicity of excess Na^＋. A large amount of Na^＋ entering cells would reduce K^＋ uptake, which leads to an imbalance of K：Na ratio in cells. One of the reasons for the reduced K^＋-uptake is the closure of K^＋-channel which is controlled by membrane potential. Calcium is usually applied to improve the growth of plants on saline soils and shows positive influence in the integrality of cell membrane. This study applied glass microelectrode technique to monitoring the NaCl-induced changes of membrane potential of root epidermal cells of maize （Zea mays L., Denghai 11） seedlings at NaCl concentrations of 0, 8, 20, 50, 100, 200 mmol L^-1, respectively. The effect of Ca^2＋ on the changes of membrane potential caused by NaCl was also studied. The results showed that： NaCl caused cell membrane depolarization. The depolarization became greater and faster with increasing of NaCl concentration. Moreover, the extent of depolarization was positively correlated with NaCl concentration. The addition of calcium postponed the depolarization, and decreased the degree of depolarization caused by NaCl. High NaCl concentration leads to depolarization of maize root cell membrane, which can partly be counteracted by calcium.

The Measurement of Membrane Potential and NO3 Activity in Root Cells Using Ion-Selective Microelectrodes

Remobilisation of nitrate in plants, especially in vacuole of plant, is mostly related to the qua- lity of agricultural products and the high nitrogen use efficiency in plants. Ion-selective microelectrodes offer a non-destructive and non-interruptive method to measure NO 3 gradients and electric potential differences across both the plasma membrane and tonoplast. Thus, a double-barrelled microelectrode backfilled with a membrane sensor for NO 3 embedded in poly vinyl chloride (PVC) can record the NO 3 activity in cytoplasm and vacuole of a cell. This paper presented how to make this kind of microelectrode and how to do the intracellular measurements on intact plants. Our result showed that nitrate activity was about 2.7 mmol L 1 in cytoplasm while 70 mmol L 1 in vacuole, which implicated that vacuole was a pool of nitrate in plants.

Interventional effect of phycocyanin on mitochondrial membrane potential and activity of PC12 cells after hypoxia/reoxygenation

BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation. DESIGN： Randomized controlled study SETTING ： Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University MATERIALS： The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells, were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide （MTT） and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA. METHODS： ① Culture of PC12 cells： PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37℃. Number of cells was regulated to 4 × 10^5 L 1, and cells were inoculated at 96-well culture plate. The final volume was 100μL. ② Model establishing and grouping： Cultured PC12 cells were randomly divided into three groups： phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L , but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group （the final concentration of 3 g/L） and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non-hypoxia group were cultured with oxygen and were measured at 1 hour after hypoxia/reoxygenation. ③ Detecting items： At 1, 2 and 3 hours after reoxygenation, absorbance （A value） of PC12 cells was measured with MTT technique so as to observe activity and quantity of cells. Fluorescence intensity of PC12 cells marked by rhodamine 123 was measured with confocal microscope in order to observe changes of mitochondrial membrane potential. MAEN OUTCOME MEASURES： Comparisons between quantity and activity of PC12 cells and mitochondria membrane potential at 1, 2 and 3 hours after reoxygenation. RESULTS： ① Effect of phycocyanin on quantity and activity of PC12 cells： A value was 0.924±0.027 in adding phycocyanin group and 0.924±0.033 in non-adding phycocyanin group. A value was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after reoxygenation （0.817±0.053, 0.838±0.037, 0.875±0.029; 0.842±0.029, 0.872±0.025, 0.906±0.023, P 〈 0.05）. A value was higher in phycocyanin group than that in model control group at 1, 2 and 3 after culture （P 〈 0.05）. With culture time being longer, A value was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. ~ Effect of phycocyanin on mitochondrial membrane potential of PC12 cells： Fluorescence intensity was 2.967±0.253 in adding phycocyanin group and 2.962±0.294 in non-adding phycocyanin group. Fluorescence intensity was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after hypoxia/reoxygenation （1.899±0.397, 2.119±0.414, 2.287±0.402; 2.191±0.377, 2.264±0.359, 2.436±0.471, P 〈 0.05）; but it was higher in phycocyanin group than that in model control group at 1, 2 and 3 after reoxygenation （P 〈 0.05）. With culture time being longer, fluorescence intensity was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. CONCLUSION： Phycocyanin and reoxygenation can protect PC12 cells after hypoxia injury through increasing mitochondrial membrane potential and cellular activity, and the effect is improved gradually with prolonging time of reoxygenation.

Ammonium Effects on Nitrate Uptake by Roots of Upland and Paddy Rice Seedlings Related to Membrane Potential Differences

Nitrate uptake characteristics and ammonium effects on nitrate uptake were compared between upland rice （Brazilian upland rice） and paddy rice （Wuyujing 3 and Yangdao 6） through the glass microelectrode technique and the concentration gradient method of uptake kinetics.Results indicated that nitrate uptake by rice seedlings and ammonium effects were depending on membrane potential of root cells.And upland rice and paddy rice presented obviously different responses.For all cultivars,the nitrate treatments induced rapid depolarization and then slow repolarization of membrane potential in root epidermal cells,and even hyperpolarization was observed when nitrate concentration was low.The membrane potential of epidermal cells in Brazilian upland rice roots was larger and its response to NO3- was bigger than those of two paddy rice cultivars.Depolarization of membrane potential was amplified when ammonium was simultaneously added with nitrate into the measure medium,but repolarization was reduced,even disappeared.Brazilian upland rice seedlings had high Vmax of nitrate uptake and low Km,furthermore,Vmax and Km were little affected by ammonium,but Vmax of Wuyujing 3 was reduced significantly.Therefore,inhibition of NH4＋ differed obviously between upland rice and paddy rice.

Effects of La^(3+)on H^+ Transmembrane Gradient and Membrane Potential in Rice Seedling Roots

The effects of LaCl 3 on membrane potential and transmembrane proton gradient for rice ( Oryza sativa ) seedling roots were studied. Highly purified plasma membrane was isolated by aqueous two phase partitioning method. Both the gradient of transmembrane proton and membrane potential were stimulated by certain low concentration of LaCl 3 and depressed by high concentration of LaCl 3. The optimal concentration of La 3+ is around 40～60 μmol·L -1 for transmembrane proton gradient and membrane potential. It shows that La 3+ can influence the generations and maintenances of membrane potential and transmembrane proton gradient in rice seedling roots.

K^+ Channels and Their Effects on Membrane Potential in Rat Bronchial Smooth Muscle Cells

In order to investigate the K+ channels and their effects on resting membrane potential (Em) and excitability in rat bronchial smooth muscle cells (BSMCs), the components of outward K+ channel currents and the effects of K+ channels on Em and tension in rat bronchial smooth muscle were observed by using standard whole-cell recording of patch clamp and isometric tension recording techniques. The results showed that under resting conditions, total outward K+ channel currents in freshly isolated BSMCs were unaffected by ATP-sensitive K+ channel blocker. There were two types of K+ currents: voltage-dependent delayed rectifier K+ channel (Kv) and large conductance calcium-activated K+ channel (BKc.) currents. 1 mmol/L 4-aminopyridine (4-AP, an inhibitor of Kv) caused a significant depolarization (from -8. 7±5. 9 mV to -25. 4±3. 1 mV, n=18, P<0. 001). In contrast, 1 mmol/L tetraethylammonium (TEA, an inhibitor of BKc.) had no significant effect on Em (from -37. 6±4. 8 mV to -36. 8±4.1mV, n=12, P>0. 05). 4-AP caused a concentration-dependent contraction in resting bronchial strips. TEA had no effect on resting tension, but application of 5 mmol/L TEA resulted in a left shift with bigger pD2(the negative logarithm of the drug concentration causing 50% of maximal effect) (from 6. 27±0. 38 to 6. 89±0. 54, n= 10, P<0. 05) in the concentration-effect curve of endothine-1, and a right shift with smaller pD2(from 8. 10±0. 23 to 7. 69±0. 08, n=10, P<0. 05) in the concentration-effect curve of isoprenaline. It was suggested that in rat BSMCs there may be two types of K+ channels, Kv and BKca, which serve distinct roles. Kv participates in the control of resting Em and tension. BKca is involved in the regulation of relaxation or contraction associated with excitation.

Arsenic trioxide induces multiple myeloma cell apoptosis via disruption of mitochondrial transmembrane potentials and activation of caspase-3

OBJECTIVE: To investigate the response of multiple myeloma (MM) cells to arsenic trioxide (As2O3) and their possible mechanisms. METHODS: Two MM-derived cell lines RPMI8226 and U266 cells were used as in vitro models. Cell apoptosis was assessed by morphology, flow cytometry, and DNA gel electrophoresis. Mitochondrial transmembrane potentials (delta psi m) were evaluated by measuring cellular Rhodamine 123 staining intensity. Protein expression was analyzed using Western blot. RESULTS: Zero point one to 0.5 mumol/L As2O3 inhibited cell proliferation and 2.0 mumol/L As2O3 induced cell apoptosis, while 1.0 mumol/L As2O3 inhibited proliferation with a weak degree of apoptosis induction in RPMI8226 and U266 cell lines. As2O3-induced apoptosis was accompanied by mitochondrial transmembrane potentials (delta psi m) collapse and caspase-3 activation in the presence of intact membrane. Glutathione depleter buthionine sulfoximine enhanced, while disulfide bond-reducing agent dithiothreitol partially antagonized As2O3-induced delta psi m collapse and apoptosis in MM cells. All-trans retinoic acid (ATRA) could also induce apoptosis in RPMI8226 cells, but it did not show any cooperative effects with As2O3. CONCLUSION: As2O3 exerts apoptosis-inducing and growth-inhibiting effects on MM cells, and mitochondrium is a pivotal and common target of As2O3 for apoptosis induction.

The role of membrane potential and calcium kinetic changes in the pathogenesis of vascular hyporeactivity during severe shock

OBJECTIVE: To determine the role of membrane potential and intracellular calcium kinetic changes in producing vascular hyporeactivity during severe hemorrhagic shock. METHODS: Rats were subjected to hemorrhagic shock (HS) for 2 hours. The spinotrapezius muscle was prepared for microscopy and the responses of arterioles in the muscle to norepinephrine (NE) were tested. The resting membrane potentials of isolated arterial strips were measured with a microelectrode. Membrane potential and intracellular Ca2+ ([Ca2+]i) changes in isolated arteriolar smooth muscle cells (ASMCs) were determined with fluorescent probes and a confocal microscopy. RESULTS: The arteriolar resting membrane potential was decreased from -36.7 +/- 6.3 mV in control to -29.2 +/- 5.3 mV concurrent with the increase of vasoreactivity to NE at 20 minutes after HS. At 120 minutes post-HS, the resting potential hyperpolarized to -51.9 +/- 9.1 mV, and NE stimulated [Ca2+]i increase was reduced to 50% of the control values during the appearance of arteriolar hyporeactivity, i.e. the NE threshold of the arteriolar response increased 15 fold 2 hours after the onset of hemorrhage as compared with normal animals. The state of vasoreactivity was closely related to the resting potential of vascular smooth muscle in hemorrhagic shock, with a correlation coefficient of 0.96. Treatment with glybenclamide, a selective blocker of ATP-sensitive K+ (KATP) channels, decreased the resting potential, increased NE-stimulated [Ca2+]i increase, and partially restored vasoreactivity in severe hemorrhagic shock. CONCLUSION: The results suggested that membrane hyperpolarization and the reduction of NE-stimulated [Ca2+]i increase in smooth muscle cells appeared to contribute to the vascular hyporeactivity in hemorrhagic shock. The mechanism is likely to involve in KATP channels.

Oligomeric Procyanidins Induce Generation of Reactive Oxygen Species and Collapse of Mitochchondrial Membrane Potential in Glioblastoma Cell Lines

Objective The aim of the present study was to clarify the mechanism underlying glioma cell death upon oligomeric procyanidins (F2) exposure. Methods The cytotoxicity of F2 on U87 (human malignant glioblastoma cell line) and C6 (rat glioma cell line) cancer cells was evaluated, and changes of mitochondrial membrane potential (MMP) and production of reactive oxygen species (ROS) in drug-treated cells were monitored. Moreover, morphological changes associated with F2-induced cells death were examined. Results F2 induced a concentration-dependent increase in ROS production and decrease in MMP. Furthermore, pre-incubation with N-acetylcysteine (NAC) and rotenone (Rt), resulted in partial inhibition of F2-induced ROS generation and marked attenuation of cell death and the cytoplasmic vacuolization induced by F2. In addition, pretreatment with Rt markedly attenuated the MMP loss in F2-treated cells. However, pretreatment with NAC only markedly attenuated the MMP loss in F2-treated C6 cells. Conclusion The increase in ROS level is at least one of mechanisms associated with F2-induced glioma cell death as well as the cytoplasmic vacuolization formation that contribute to the cytotoxicity of F2 in glioma cells.

Voltage-gated potassium channel Kvl.3 in rabbit ciliary epithelium regulates the membrane potential via coupling intracellular calcium

Background The cell layer of the ciliary epithelium is responsible for aqueous humor secretion and maintenance. Ion channels play an important role in these processes. The main aim of this study was to determine whether the well-characterized members of the Kvl family （Kv1.3） contribute to the Kv currents in ciliary epithelium. Methods New Zealand White rabbits were maintained in a 12 hours light/dark cycle. Ciliary epithelium samples were isolated from the rabbits. We used Western blotting and immunocytochemistry to identify the expression and location of a voltage-gated potassium channel Kvl.3 in ciliary body epithelium. Membrane potential change after adding of Kvl.3 inhibitor margatoxin （MgTX） was observed with a fluorescence method. Results Western blotting and immunocytochemical studies showed that the Kv1.3 protein expressed in pigment ciliary epithelium and nonpigment ciliary epithelium, however it seemed to express more in the apical membrane of the nonpigmented epithelial cells. One nmol/L margatoxin, a specific inhibitor of Kv1.3 channels caused depolarization of the cultured nonpigmented epithelium （NPE） membrane potential. The cytosolic calcium increased after NPE cell depolarization, this increase of cytosolic calcium was partially blocked by 12.5 μmol/L dantrolene and 10 μmol/L nifedipine. These observations suggest that Kv1.3 channels modulate ciliary epithelium potential and effect calcium dependent mechanisms. Conclusion Kv1.3 channels contribute to K＋ efflux at the membrane of rabbit ciliary epithelium.

GPCR activation:protonation and membrane potential

GPCR proteins represent the largest family of signaling membrane proteins in eukaryotic cells.Their importance to basic cell biology,human diseases,and pharma-ceutical interventions is well established.Many crystal structures of GPCR proteins have been reported in both active and inactive conformations.These data indicate that agonist binding alone is not suffi cient to trigger the conformational change of GPCRs necessary for binding of downstream G-proteins,yet other essential factors re-main elusive.Based on analysis of available GPCR crystal structures,we identifi ed a potential conformational switch around the conserved Asp2.50,which consistently shows distinct conformations between inactive and active states.Combining the structural information with the current literature,we propose an energy-coupling mechanism,in which the interaction between a charge change of the GPCR protein and the membrane potential of the living cell plays a key role for GPCR activation.

Parkinson’s disease-associated VPS35 mutant reduces mitochondrial membrane potential and impairs PINK1/Parkinmediated mitophagy

Background:Mitochondrial dysfunction plays a prominent role in the pathogenesis of Parkinson’s disease(PD),and several genes linked to familial PD,including PINK1(encoding PTEN-induced putative kinase 1[PINK1])and PARK2(encoding the E3 ubiquitin ligase Parkin),are directly involved in processes such as mitophagy that maintain mitochondrial health.The dominant p.D620N variant of vacuolar protein sorting 35 ortholog(VPS35)gene is also associated with familial PD but has not been functionally connected to PINK1 and PARK2.Methods:To better mimic and study the patient situation,we used CRISPR-Cas9 to generate heterozygous human SH-SY5Y cells carrying the PD-associated D620N variant of VPS35.These cells were treated with a protonophore carbonyl cyanide m-chlorophenylhydrazone(CCCP)to induce the PINK1/Parkin-mediated mitophagy,which was assessed using biochemical and microscopy approaches.Results:Mitochondria in the VPS35-D620N cells exhibited reduced mitochondrial membrane potential and appeared to already be damaged at steady state.As a result,the mitochondria of these cells were desensitized to the CCCPinduced collapse in mitochondrial potential,as they displayed altered fragmentation and were unable to accumulate PINK1 at their surface upon this insult.Consequently,Parkin recruitment to the cell surface was inhibited and initiation of the PINK1/Parkin-dependent mitophagy was impaired.Conclusion:Our findings extend the pool of evidence that the p.D620N mutation of VPS35 causes mitochondrial dysfunction and suggest a converging pathogenic mechanism among VPS35,PINK1 and Parkin in PD.

Correlations of Sperm Mitochondrial Membrane Potential with Semen Parameters and Male Obesity

Background:To investigate the correlations of sperm mitochondrial membrane potential(MMP)with semen parameters and body mass index(BMI)in males with obesity.Methods:Semen samples were obtained by masturbation after 3-7 days of sexual abstinence from males who visited semen collect room of Shanghai Ninth People’s Hospital.Conventional semen analyses were performed by computer-aided sperm analysis(CASA),and sperm morphology was analyzed by modified Papanicolaou staining.Spermatozoa were stained by JC-1 to evaluate MMP through flow cytometry.Results:Sperm MMP of asthenozoospermia group(41.24%±9.71%)was significantly lower than that in control group(56.68%±11.13%).MMP was negatively correlated with BMI(r=−0.25,P<0.01),but positively correlated with total sperm motility(r=0.63,P<0.01),motility of progressive sperm(r=0.64,P<0.01),and normal sperm morphology rate(r=0.37,P<0.01).In addition,MMP showed no significant correlations with age,volume of semen,sperm concentration,sperm count,and other indexes.Conclusions:Sperm MMP is an important index in the evaluation of sperm function,and detection of MMP may provide references for the diagnosis and treatment of male infertility.

A Convolutional Neural Network Model for Classifying Cardiac Membrane Potential Patterns

Investigation of the electrophysiological mechanisms that induce arrhythmias is one of the most important issues in scientific research.Since computational cardiology allows the systematic dissection of causal mechanisms of observed effects,simulations based on the ionic channel mathematical models have become one of the most widely used methods.To reduce themanual classification of different types of membrane potential patterns produced during simulations,a convolutional neural network is developed in this paper.The model includes 4convolution layers,4 pooling layers and a fully connected layer.An activation function of Re LU is used.Before machine learning,all the pattems are calibrated,cut,and normalized to a uniform format with a size of 256×256.The contour boundary of each pattern is extracted using the maximum between-class variance method.In the examination,the proposed learning algorithm shows a recognition accuracy of 97%on test data set after training.

Immp2l Mutation Induces Mitochondrial Membrane Depolarization and Complex Ⅲ Activity Suppression after Middle Cerebral Artery Occlusion in Mice

Objective We previously reported that mutations in inner mitochondrial membrane peptidase 2-like(Immp2l)increase infarct volume,enhance superoxide production,and suppress mitochondrial respiration after transient cerebral focal ischemia and reperfusion injury.The present study investigated the impact of heterozygous Immp2l mutation on mitochondria function after ischemia and reperfusion injury in mice.Methods Mice were subjected to middle cerebral artery occlusion for 1 h followed by 0,1,5,and 24 h of reperfusion.The effects of Immp2l^(+/−)on mitochondrial membrane potential,mitochondrial respiratory complex III activity,caspase-3,and apoptosis-inducing factor(AIF)translocation were examined.Results Immp2l^(+/−)increased ischemic brain damage and the number of TUNEL-positive cells compared with wild-type mice.Immp2l^(+/−)led to mitochondrial damage,mitochondrial membrane potential depolarization,mitochondrial respiratory complex III activity suppression,caspase-3 activation,and AIF nuclear translocation.Conclusion The adverse impact of Immp2l^(+/−)on the brain after ischemia and reperfusion might be related to mitochondrial damage that involves depolarization of the mitochondrial membrane potential,inhibition of the mitochondrial respiratory complex III,and activation of mitochondria-mediated cell death pathways.These results suggest that patients with stroke carrying Immp2l^(+/−)might have worse and more severe infarcts,followed by a worse prognosis than those without Immp2l mutations.

Electrical stimulation modulates injury potentials in rats after spinal cord injury

An injury potential is the direct current potential difference between the site of spinal cord injury and the healthy nerves. Its initial amplitude is a significant indicator of the severity of spinal cord injury, and many cations, such as sodium and calcium, account for the major portion of injury potentials. This injury potential, as wel as injury current, can be modulated by direct current field stimulation;however, the appropriate parameters of the electrical field are hard to define. In this paper, injury potential is used as a parameter to adjust the intensity of electrical stimulation. Injury potential could be modulated to slightly above 0 mV （as the anode-centered group） by placing the anodes at the site of the injured spinal cord and the cathodes at the rostral and caudal sections, or around-70 mV, which is resting membrane potential （as the cathode-centered group） by reversing the polarity of electrodes in the anode-centered group. In addition, rats receiving no electrical stimulation were used as the control group. Results showed that the absolute value of the injury potentials acquired after 30 minutes of electrical stimulation was higher than the control group rats and much lower than the initial absolute value, whether the anodes or the cathodes were placed at the site of injury. This phenomenon il ustrates that by changing the polarity of the electrical field, electrical stimulation can effectively modulate the injury potentials in rats after spinal cord injury. This is also beneficial for the spontaneous repair of the cel membrane and the reduction of cation influx.

Study on the in vitro anti ovarian cancer effect and mechanism of quinazoline derivative(N111)

Objective:To study the anti-ovarian cancer effect and mechanism of Quinazoline derivative(N111)in vitro;Method:Using an online database to predict the therapeutic targets of N111 for ovarian cancer,and conducting biological functional analysis of the therapeutic targets.The experiment was divided into N111 treatment group(N111 compound group),positive control group(cisplatin group),and negative control group(DMSO group);After grouping,MTT assay was used to detect cell proliferation;Morphological observation was used to observe changes in cell morphology;JC-1 and DCFH-DA probes were used to detect the changes of mitochondrial Membrane potential and intracellular reactive oxygen species;PI,Annexin V-FITC,and DAPI staining were used to detect cell cycle arrest and apoptosis;Clone formation experiments and scratch tests were conducted to detect the cell's ability to form clones and migrate;Western blot method was used to detect the expression level of related proteins.Result:The biological function research results show that the biological function of N111 anti ovarian cancer target protein suggests that the target function aggregates human diseases,inflammation,tumors,and other aspects.Compared with the control group,N111 has a significant inhibitory effect on the proliferation of ovarian cancer cells(IC50=14.62 mmol/L)(P<0.0001);In a concentration dependent manner,it inhibited the formation and migration of single cell colonies,and induced the disorder of mitochondrial Membrane potential,ROS and cell cycle arrest in S phase(P<0.0001);As the concentration of N111 treatment increased,the expression levels of Bcl2,Caspase 3,P-AKT,and SHIP2 decreased,while the expression levels of AKT remained unchanged.The expression levels of Bax and Cleared Caspase 3 increased(P<0.0001).Conclusion:Compound N111 inhibits SHIP2,promotes ROS level disorder,weakens the activation of AKT signaling pathway,and thus inhibits the proliferation,migration,and clone formation of tumor cell A2780,inducing cell apoptosis.

Lycium barbarum polysaccharides protects retinal ganglion cells against oxidative stress injury

The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.

Polysaccharides from Angelica sinensis alleviate neuronal cell injury caused by oxidative stress

Angelica sinensis has antioxidative and neuroprotective effects. In the present study, we aimed to determine the neuroprotective effect of polysaccharides isolated from Angelica sinensis. In a pre-liminary experiment, Angelica sinensis polysaccharides not only protected PC12 neuronal cells from H202-induced cytotoxicity, but also reduced apoptosis and intracellular reactive oxygen species levels, and increased the mitochondrial membrane potential induced by H202 treatment. In a rat model of local cerebral ischemia, we further demonstrated that Angelica sinensis poly-saccharides enhanced the antioxidant activity in cerebral cortical neurons, increased the number of microvessels, and improved blood flow after ischemia. Our findings highlight the protective role of polysaccharides isolated from Angelica sinensis against nerve cell injury and impairment caused by oxidative stress.