Wanhong Zuo

University of Jinan (Jinan, China), Chi-nan-shih, Shandong Sheng, China

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Publications (13)47.95 Total impact

  • Jiang-Hong Ye, Yuwei Liu, Wanhong Zuo
    Anesthesia and analgesia 02/2014; 118(2):485. · 3.08 Impact Factor
  • Yu-Wei Liu, Wanhong Zuo, Jiang-Hong Ye
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    ABSTRACT: BACKGROUND:The cellular mechanisms underlying the sedative effect of general anesthetics are not completely understood. Accumulating evidence indicates that the ventrolateral preoptic area (VLPO) of the hypothalamus plays a critical role. The VLPO contains 2 major types of neurons, the noradrenalin-inhibited GABAergic projecting neurons (NA(-) neurons) and the noradrenalin-excited interneurons (NA(+) neurons) which are probably also γ-aminobutyric acid (GABA)-containing neurons. Our previous work suggests that NA(-) neurons are normally under the inhibitory control of NA(+) neurons. Previous studies also show that GABAergic agents including propofol activate GABAergic projecting neurons in the VLPO, which is believed to lead to the inhibition of the arousal-producing nuclei in the tuberomammillary nucleus and sedation. However, how propofol activates VLPO neurons remains unclear. We explored the possibility that propofol activates NA(-) neurons indirectly, by inhibiting GABAergic transmission including those from VLPO NA(+) neurons.METHODS:Electrophysiological activities were recorded from VLPO cells in acute brain slices of rats.RESULTS:Propofol facilitates the discharges of NA(-) neurons and reduces the frequency, but not the amplitude of spontaneous GABAergic inhibitory postsynaptic currents in NA(-) neurons. Conversely, propofol suppressed the discharges of NA(+) neurons.CONCLUSION:Propofol excites VLPO NA(-) neurons by reducing GABAergic transmission, at least in part by inhibiting VLPO NA(+) neurons. This may be a critical mechanism contributing to propofol-induced sedation.
    Anesthesia and analgesia 06/2013; · 3.08 Impact Factor
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    ABSTRACT: The functions of chloride channels in preconditioning-induced cell protection remain unclear. In this report, we show that the volume-activated chloride channels play a key role in hydrogen peroxide (H2O2) preconditioning-induced cell protection in pheochromocytoma PC12 cells. The preconditioning with 100 μM H2O2 for 90 min protected the cells from injury induced by long period exposure to 300 μM H2O2. The protective effect was attenuated by pretreatment with the chloride channel blockers, 5-nitro-2-3-phenylpropylamino benzoic acid (NPPB) and tamoxifen. H2O2 preconditioning directly activated a chloride current, which was moderately outward-rectified and sensitive to the chloride channel blockers and hypertonicity-induced cell shrinkage. H2O2 preconditioning functionally up-regulated the activities of volume-activated chloride channels and enhanced the regulatory volume decrease when exposure to extracellular hypotonic challenges. In addition, acute application of H2O2 showed distinctive actions on cell volume and membrane permeability in H2O2 preconditioned cells. In H2O2 preconditioned cells, acute application of 300 μM H2O2 first promptly induced a decrease of cell volume and enhancement of cell membrane permeability, and then, cell volume was maintained at a relatively stable level and the facilitation of membrane permeability was reduced. Conversely, in control cells, 300 μM H2O2 induced a slow but persistent apoptotic volume decrease (AVD) and facilitation of membrane permeability. H2O2 preconditioning also significantly up-regulated the expression of ClC-3 protein, the molecular candidate of the volume-activated chloride channel. These results suggest that H2O2 preconditioning can enhance the expression and functional activities of volume-activated chloride channels, thereby modulate cell volume and cell membrane permeability, which may contribute to neuroprotection against oxidant-induced injury.
    Molecular Neurobiology 04/2013; · 5.47 Impact Factor
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    ABSTRACT: Cocaine administration can be both rewarding and aversive. While much effort has gone to investigating the rewarding effect, the mechanisms underlying cocaine-induced aversion remain murky. There is increasing evidence that the lateral habenula (LHb), a small epithalamic structure, plays a critical role in the aversive responses of many addictive drugs including cocaine. However, the effects of cocaine on LHb neurons are not well explored. Here we show that, in acute brain slices from rats, cocaine depolarized LHb neurons and accelerated their spontaneous firing. The AMPA and NMDA glutamate receptor antagonists, 6, 7-dinitroquinoxaline-2, 3-dione, DL-2-amino-5-phosphono-valeric acid, attenuated cocaine-induced acceleration. In addition, cocaine concentration-dependently enhanced glutamatergic excitation: enhanced the amplitude but reduced the paired pulse ratio of EPSCs elicited by electrical stimulations, and increased the frequency of spontaneous EPSCs in the absence and presence of tetrodotoxin. Dopamine and the agonists of dopamine D1 (SKF 38393) and D2 (quinpirole) receptors, as well as the dopamine transporter blocker (GBR12935), mimicked the effects of cocaine. Conversely, both D1 (SKF 83566) and D2 (raclopride) antagonists substantially attenuated cocaine's effects on EPSCs and firing. Together, our results provide evidence that cocaine may act primarily via an increase in dopamine levels in the LHb that activates both D1 and D2 receptors on the glutamatergic terminals which make synapses on LHb neurons. This leads to an increase in glutamate release and LHb neuron activity, and may contribute to the aversive effect of cocaine observed in vivo.
    Neuropharmacology 01/2013; · 4.11 Impact Factor
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    ABSTRACT: It has been demonstrated previously by us that cyclin D1 and ClC-3 play important roles in regulation of the cell cycle in nasopharyngeal carcinoma cells. The action of cyclin D1 on the functional activities and expression of chloride channels were investigated in nasopharyngeal carcinoma CNE-2Z cells in this study. The results indicated that enhanced cyclin D1 expression increased the activation of volume-activated chloride currents and promoted the expression of ClC-3 chloride channel proteins. The fluorescence resonance energy transfer (FRET) experiments demonstrated that the distance between cyclin D1 and ClC-3 was less than 10nm, and there existed interaction between the two proteins. ClC-3 was partially colocalized with cyclin D1 and CDK4/6. Dialyzing CDK4 antibodies into cells via recording pipettes activated a chloride current, but dialysis of CDK 6 antibodies inhibited basal and volume-activated Cl(-) currents. The CDK4/6 inhibitor fascaplysin chloride hydrate (highly selective for CDK4/cyclin D1 with IC(50)=0.35μM and less selective for CDK6/D1 with IC(50)=3.4μM) activated a chloride current in low concentration, but did not show significantly facilitative effects on the current in high concentration. In conclusion, our data suggest that the ClC-3 chloride channel is an important target of cyclin D1. Cyclin D 1 may regulate the functional activities of the chloride channel via CDK4 and CDK6, and/or the expression of the chloride channel. Cyclin D1-CDK4 complexes may phosphorylate chloride channels resulting in inhibition or inactivation of the channels, and cyclin D1-CDK6 complexes may facilitate the activation of chloride channels.
    The international journal of biochemistry & cell biology 12/2012; · 4.89 Impact Factor
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    ABSTRACT: Acid-activated chloride currents have been reported in several cell types and may play important roles in regulation of cell function. However, the molecular identities of the channels that mediate the currents are not defined. In this study, activation of the acid-induced chloride current and the possible candidates of the acid-activated chloride channel were investigated in human nasopharyngeal carcinoma cells (CNE-2Z). A chloride current was activated when extracellular pH was reduced to 6.6 from 7.4. However, a further decrease of extracellular pH to 5.8 inhibited the current. The current was weakly outward-rectified and was suppressed by hypertonicity-induced cell shrinkage and by the chloride channel blockers 5-nitro-2-3-phenylpropylamino benzoic acid (NPPB), tamoxifen, and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS). The permeability sequence of the channel to anions was I(-) > Br(-) > Cl(-) > gluconate(-). Among the ClC chloride channels, ClC-3 and ClC-7 were strongly expressed in CNE-2Z cells. Knockdown of ClC-3 expression with ClC-3 small interfering (si)RNA prevented the activation of the acid-induced current, but silence of ClC-7 expression with ClC-7 siRNA did not significantly affect the current. The results suggest that the chloride channel mediating the acid-induced chloride current was volume sensitive. ClC-3 is a candidate of the channel proteins that mediate or regulate the acid-activated chloride current in nasopharyngeal carcinoma cells.
    AJP Cell Physiology 04/2012; 303(1):C14-23. · 3.71 Impact Factor
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    ABSTRACT: It is known that the posterior ventral tegmental area (p-VTA) differs from the anterior VTA (a-VTA) in that rats learn to self-administer ethanol into the p-VTA, but not into the a-VTA. Because activation of VTA dopaminergic neurons by ethanol is a cellular mechanism underlying the reinforcement of ethanol consumption, we hypothesized that ethanol may exert different effects on dopaminergic neurons in the p-VTA and a-VTA. In patch-clamp recordings in midbrain slices from young rats (postnatal days 22-32), we detected no significant difference in electrophysiological properties between p-VTA and a-VTA dopaminergic neurons. However, acute exposure to ethanol (21-86 mM) stimulated p-VTA dopaminergic neurons but suppressed a-VTA dopaminergic neurons. Conversely, ethanol (>21 mM) dose-dependently reduced the frequency of the GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs) generated by inhibitory neuronal firing but not miniature inhibitory postsynaptic currents (mIPSCs) in p-VTA dopaminergic neurons. By contrast, ethanol increased the frequency and amplitude of both sIPSCs and mIPSCs in a-VTA dopaminergic neurons. All of these effects of ethanol were abolished by a GABA(A) receptor antagonist. There was a strong negative correlation between ethanol-evoked modulation of sIPSCs and neuronal firing in VTA dopaminergic neurons. These results indicate that GABAergic inputs play an important role in ethanol's actions in the VTA. The differential effects of ethanol on sIPSCs and neuronal firing in the p-VTA and a-VTA could be the basis for ethanol reinforcement via the p-VTA.
    Journal of Pharmacology and Experimental Therapeutics 12/2011; 341(1):33-42. · 3.89 Impact Factor
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    ABSTRACT: Previous studies in vivo have shown that salsolinol, the condensation product of acetaldehyde and dopamine, has properties that may contribute to alcohol abuse. Although opioid receptors, especially the μ-opioid receptors (MORs), may be involved, the cellular mechanisms mediating the effects of salsolinol have not been fully explored. In the current study, we used whole-cell patch-clamp recordings to examine the effects of salsolinol on dopamine neurons of the ventral tegmental area (VTA) in acute brain slices from Sprague-Dawley rats. Salsolinol (0.01-1 μM) dose-dependently and reversibly increased the ongoing firing of dopamine neurons; this effect was blocked by naltrexone, an antagonist of MORs, and gabazine, an antagonist of GABA(A) receptors. We further showed that salsolinol reduced the frequency without altering the amplitude of spontaneous GABA(A) receptor-mediated inhibitory postsynaptic currents in dopamine neurons. The salsolinol-induced reduction was blocked by both naltrexone and [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin, an agonist of MORs. Thus, salsolinol excites VTA-dopamine neurons indirectly by activating MORs, which inhibit GABA neurons in the VTA. This form of disinhibition seems to be a novel mechanism underlying the effects of salsolinol.
    Journal of Pharmacology and Experimental Therapeutics 12/2011; 341(1):43-50. · 3.89 Impact Factor
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    ABSTRACT: We have previously shown that chloride channel activities were cell cycle-dependent and were involved in cell proliferation in nasopharyngeal carcinoma cells. In this study, the expression and roles of volume-activated chloride channels in cell growth were investigated in the poorly-differentiated human nasopharyngeal carcinoma cell (CNE-2Z) and its counterpart, the normal human nasopharyngeal epithelial cell (NP69-SV40T). Consistent with growth ability, the background chloride currents recorded under isotonic condition, the volume-activated chloride currents induced by 47% hypotonic challenges and the hyponinicity-induced regulatory volume decrease (RVD) were much larger in CNE-2Z cells than in NP69-SV40T cells, suggesting the up-regulation of expression of volume-activated chloride channels in cancerous cells. This was proved by the up-regulation of ClC-3 proteins, a candidate of volume-activated chloride channels, in the cancerous cells. Functional inhibition of chloride channel activities by the chloride channel blockers, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) and tamoxifen, and knock-down of ClC-3 expression by specific ClC-3 siRNA attenuated the background currents, suppressed the activation of volume-activated chloride currents, decreased the hyponinicity-induced RVD and inhibited cell growth in the cancerous and normal cells. However, the sensitivities of the cancerous cells were much higher than that of the normal cells. Our data suggest that volume-activated chloride channels play a more important role in control cell proliferation in the cancerous cells than in the normal cells; the growth of cancerous cells is more dependent on the activities of volume-activated chloride channels than that of the normal cells. ClC-3 protein may be considered as a potential tumor marker and therapeutic target for human nasopharyngeal carcinoma.
    Biochemical pharmacology 11/2011; 83(3):324-34. · 4.25 Impact Factor
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    ABSTRACT: Chloride channels are expressed ubiquitously in different cells. However, the activation and roles of volume-activated chloride channels under normal isotonic conditions are not clarified, especially in lymphatic cells. In this study, the activation of basal and volume-activated chloride currents and their roles in maintenance of basal cell volume under isotonic conditions were investigated in human acute lymphoblastic leukemia Molt4 cells. The patch-clamp technique and time-lapse image analysis were employed to record whole-cell currents and cell volume changes. Under isotonic conditions, a basal chloride current was recorded. The current was weakly outward-rectified and volume-sensitive and was not inactivated obviously in the observation period. A 47% hypertonic bath solution and the chloride channel blockers NPPB and tamoxifen suppressed the current. Exposure of cells to 47% hypotonic bath solution activated further the basal current. The hypotonicity-activated current possessed properties similar to those of the basal current and was inhibited by NPPB, tamoxifen, ATP and hypertonic bath solution. Furthermore, extracellular hypotonic challenges swelled the cells and induced a regulatory volume decrease (RVD). Extracellular applications of NPPB, tamoxifen and ATP swelled the cells under isotonic conditions and inhibited the RVD induced by hypotonic cell swelling. The results suggest that some volume-activated chloride channels are activated under isotonic conditions, resulting in the appearance of the basal chloride current, which plays an important role in the maintenance of basal cell volume in lymphoblastic leukemia cells. Chloride channels can be activated further to induce a regulatory volume recovery when cells are swollen.
    Journal of Membrane Biology 02/2011; 240(2):111-9. · 2.48 Impact Factor
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    ABSTRACT: Stretch-activated chloride currents (I(Cl,SA) ) have been considered to be a component of volume-activated chloride currents (I(Cl,vol) ) for some time. This is due to a similarity in biophysical and pharmacological properties that involve a membrane curvature-induced mechanism and rearrangement of the cytoskeleton induced by cell swelling or membrane stretch. In the present study, we demonstrated that current density, along with the time taken from the activation of currents to the peak, were significantly different between the two currents, in highly metastatic human hepatocellular carcinoma cells. In addition, the activation of I(Cl,vol) or I(Cl,SA), induced maximally by hypotonic solutions or membrane stretch, respectively, did not affect the following activation of the other one. Moreover, neither inhibition of I(Cl,vol) by sh-ClC-3 transfection, nor functional blocking of I(Cl,vol) by intracellular dialysis of anti-ClC-3 antibody had an effect on the activation and properties of I(Cl,SA). Collectively, our results suggest that I(Cl,SA) is different from I(Cl,vol) in activation mechanism and/or in molecular entity responsible for formation of the currents. ClC-3 is involved in the activation of I(Cl,vol), but not of I(Cl,SA).
    Journal of Cellular Physiology 10/2010; 226(5):1176-85. · 4.22 Impact Factor
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    ABSTRACT: Lithium salts have been used as a class of mood stabilizing agents to treat bipolar disorders for over a century. Although lithium is known to affect cell proliferation, apoptosis and migration, the underlying mechanisms have not been well-explored. Emerging evidence indicates that cell volume regulation and volume-activated chloride channels are involved in cell proliferation, apoptosis and migration. To understand the mechanism of lithium's actions, we investigated the effect of lithium chloride on cell volume regulation and volume-activated chloride channels in the nasopharyngeal carcinoma cell line CNE-2Z. Our results show that lithium chloride attenuates regulatory volume decrease induced by 47% hypotonic challenges in a concentration-dependent manner with an IC(50) of 756 microM. Using the patch clamp techniques, we further show that lithium chloride concentration-dependently (IC(50)=440 microM) inhibits the volume-activated chloride current as well as the background chloride current. Furthermore, using a nanoscale atomic force microscope, we show that lithium chloride prevents the hypotonic challenge-induced changes in the ultrastructures of the cell membrane. These changes include an increase in the number and the size of the small holes, which are observed in the surface of the cell membrane under isotonic conditions. The lithium chloride-induced inhibition in cell volume regulation, in volume-activated chloride current and in the ultrastructures of the cell membrane may contribute to its effects on cell proliferation, apoptosis and migration.
    European journal of pharmacology 09/2010; 641(2-3):88-95. · 2.59 Impact Factor
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    ABSTRACT: Chloride channel activity is one of the critical factors responsible for cell apoptotic volume decrease (AVD). However, the roles of chloride channels in apoptosis have not been fully understood. In the current study, we assessed the role of chloride channels in hydrogen peroxide (H(2)O(2))-induced apoptosis of pheochromocytoma cells (PC12). Extracellular application of H(2)O(2) activated a chloride current and induced cell volume decrease in a few minutes. Incubation of cells with H(2)O(2) elevated significantly the membrane permeability to the DNA dye Hoechst 33258 in 1h and induced apoptosis of most PC12 cells tested in 24h. The chloride channel blocker NPPB (5-nitro-2-(3-phenylpropylamino)-benzoate) prevented appearance of H(2)O(2)-induced high membrane permeability and cell shrinkage, suppressed H(2)O(2)-activated chloride currents and protected PC12 cells from apoptosis induced by H(2)O(2). The results suggest that chloride channels may contribute to H(2)O(2)-induced apoptosis by ways of elevation of membrane permeability and AVD in PC12 cells.
    Biochemical and Biophysical Research Communications 08/2009; 387(4):666-70. · 2.28 Impact Factor

Publication Stats

43 Citations
47.95 Total Impact Points

Institutions

  • 2013
    • University of Jinan (Jinan, China)
      Chi-nan-shih, Shandong Sheng, China
  • 2011–2013
    • Rutgers New Jersey Medical School
      • Department of Medicine (RWJ Medical School)
      Newark, New Jersey, United States
  • 2009–2013
    • Jinan University (Guangzhou, China)
      Shengcheng, Guangdong, China
  • 2010
    • Guangdong Pharmaceutical University
      Shengcheng, Guangdong, China