Key Laboratory of Neural and Vascular Biology

Hebei, China

Key Laboratory of Neural and Vascular Biology

Hebei, China
SEARCH FILTERS
Time filter
Source Type

Zhang F.,Key Laboratory of Neural and Vascular Biology | Zhang F.,Key Laboratory of New Drug Pharmacology and Toxicology | Zhang F.,Hebei Medical University | Mi Y.,Key Laboratory of Neural and Vascular Biology | And 17 more authors.
British Journal of Pharmacology | Year: 2013

Background and Purpose Modulation of Kv7/M channel function represents a relatively new strategy to treat neuronal excitability disorders such as epilepsy and neuropathic pain. We designed and synthesized a novel series of pyrazolo[1,5-A] pyrimidin-7(4H)-one compounds, which activate K v7 channels. Here, we characterized the effects of the lead compound, QO-58, on Kv7 channels and investigated its mechanism of action. Experimental Approach A perforated whole-cell patch technique was used to record Kv7 currents expressed in mammalian cell lines and M-type currents from rat dorsal root ganglion neurons. The effects of QO-58 in a rat model of neuropathic pain, chronic constriction injury (CCI) of the sciatic nerve, were also examined. Key Results QO-58 increased the current amplitudes, shifted the voltage-dependent activation curve in a more negative direction and slowed the deactivation of Kv7.2/Kv7.3 currents. QO-58 activated Kv7.1, Kv7.2, Kv7.4 and Kv7.3/K v7.5 channels with a more selective effect on Kv7.2 and Kv7.4, but little effect on Kv7.3. The mechanism of QO-58's activation of Kv7 channels was clearly distinct from that used by retigabine. A chain of amino acids, Val224Val 225Tyr226, in Kv7.2 was important for QO-58 activation of this channel. QO-58 enhanced native neuronal M currents, resulting in depression of evoked action potentials. QO-58 also elevated the pain threshold of neuropathic pain in the sciatic nerve CCI model. Conclusions and Implications The results indicate that QO-58 is a potent modulator of K v7 channels with a mechanism of action different from those of known Kv7 openers. Hence, QO-58 shows potential as a treatment for diseases associated with neuronal hyperexcitability. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.


Du X.N.,Key Laboratory of Neural and Vascular Biology | Zhang X.,Key Laboratory of Neural and Vascular Biology | Qi J.L.,Key Laboratory of Neural and Vascular Biology | Qi J.L.,Hebei Medical University | And 8 more authors.
British Journal of Pharmacology | Year: 2011

BACKGROUND AND PURPOSE Celecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor used for the treatment of pain and inflammation. Emerging and accumulating evidence suggests that celecoxib can affect cellular targets other than COX, such as ion channels. In this study, we characterized the effects of celecoxib on K v7 K + channels and compared its effects with the well-established K v7 channel opener retigabine. EXPERIMENTAL APPROACH A perforated whole-cell patch technique was used to record K v7currents expressed in HEK 293 cells and M-type currents from rat superior cervical ganglion neurons. KEY RESULTS Celecoxib enhanced K v7.2-7.4, K v7.2/7.3 and K v7.3/7.5 currents but inhibited K v7.1 and K v7.1/KCNE1 currents and these effects were concentration dependent. The IC 50 value for inhibition of K v7.1 channels was approximately 4 μM and the EC 50 values for activation of K v7.2-7.4, K v7.2/K v7.3 and K v7.3/K v7.5 channels were approximately 2-5 μM. The effects of celecoxib were manifested by increasing current amplitudes, shifting the voltage-dependent activation curve in a more negative direction and slowing the deactivation of K v7 currents. 2,5-Dimethyl-celecoxib, a celecoxib analogue devoid of COX inhibition activity, has similar but greater effects on K v7currents. K v7.2(A235T) and K v7.2(W236L) mutant channels, which have greatly attenuated responses to retigabine, showed a reversed response to celecoxib, from activation to inhibition. CONCLUSIONS AND IMPLICATIONS These results suggest that K v7 channels are targets of celecoxib action and provide new mechanistic evidence for understanding the effects of celecoxib. They also provide a new approach to developing K v7 modulators and for studying the structure-function relationship of K v7 channels. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.


Chen X.,Key Laboratory of Neural and Vascular Biology | Chen X.,Hebei Medical University | Zhang X.,Key Laboratory of Neural and Vascular Biology | Zhang X.,Hebei Medical University | And 12 more authors.
Journal of Biological Chemistry | Year: 2011

In a previous study, we showed that membrane depolarization induced elevation of membrane phosphatidylinositol 4,5-bisphosphates (PtdIns(4,5)P 2, also known as PIP 2) and subsequently increased the KCNQ2/Q3 currents expressed in Xenopus oocytes through increased PI4 kinase activity. In this study, the underlying mechanism for this depolarization- induced enhancement of PIP 2 synthesis was further investigated. Our results indicate that activation of protein kinase C (PKC) isozyme βII was responsible for the enhanced PIP 2 synthesis. We found that phorbol-12-myristate, 13-acetate (PMA), an activator of PKC, mimicked the effects of the membrane depolarization by increasing KCNQ2/Q3 activity, elevating membrane PIP 2 levels and increasing activity of PI4 kinase β. Furthermore, membrane depolarization enhanced PKC activity. The effects of both depolarization and PMA were blocked by a PKC inhibitor or PI4 kinase β RNA interference. Further results demonstrate that the depolarization selectively activated the PKC βII isoform and enhanced its interaction with PI4 kinase β. These results reveal that the depolarization-induced elevation of membrane PIP 2 is through activation of PKC and the subsequent increased activity of PI4 kinase β. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.


Xu J.-X.,Key Laboratory of Neural and Vascular Biology | Xu J.-X.,Hebei Medical University | Si M.,Key Laboratory of Neural and Vascular Biology | Si M.,Hebei Medical University | And 13 more authors.
Journal of Biological Chemistry | Year: 2014

Background: The mechanism and significance of phosphoinositide metabolism during heart stress stimulations are not clear. Results: Norepinephrine and angiotensin II increase cardiac phosphatidylinositol 4,5-bisphosphate levels via an enhanced interaction between phosphatidylinositol 4-kinase III and PKC, which correlate with a maintained systolic function. Conclusion: Cardiac phosphoinositide turnover is enhanced. Significance: A novel mechanism of phosphoinositide metabolism is described for modulation of cardiac function. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.


Guan B.,Key Laboratory of Neural and Vascular Biology | Guan B.,Key Laboratory of Pharmacology and Toxicology for New Drugs | Guan B.,Hebei Medical University | Chen X.,Key Laboratory of Neural and Vascular Biology | And 5 more authors.
Methods in Molecular Biology | Year: 2013

Two-electrode voltage clamp (TEVC) is a conventional electrophysiological technique used to artificially control the membrane potential (V m) of large cells to study the properties of electrogenic membrane proteins, especially ion channels. It makes use of two intracellular electrodes - a voltage electrode as V m sensor and a current electrode for current injection to adjust the V m, thus setting the membrane potential at desired values and recording the membrane current to analyze ion channel activities. Here we describe the use of TEVC in combination with exogenous mRNA expression in Xenopus oocytes for ion channel recording. © 2013 Springer Science+Business Media, LLC.


Pang C.-L.,Key Laboratory of Molecular Biophysics | Pang C.-L.,Hebei University of Technology | Yuan H.-B.,Key Laboratory of Molecular Biophysics | Yuan H.-B.,Hebei University of Technology | And 18 more authors.
Journal of Computer-Aided Molecular Design | Year: 2015

Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Transmembrane protein 16A (TMEM16A) has been confirmed as the molecular counterpart of CaCCs which greatly pushes the molecular insights of CaCCs forward. However, the detailed mechanism of Ca2+ binding and activating the channel is still obscure. Here, we utilized a combination of computational and electrophysiological approaches to discern the molecular mechanism by which Ca2+ regulates the gating of TMEM16A channels. The simulation results show that the first intracellular loop serves as a Ca2+ binding site including D439, E444 and E447. The experimental results indicate that a novel residue, E447, plays key role in Ca2+ binding. Compared with WT TMEM16A, E447Y produces a 30-fold increase in EC50 of Ca2+ activation and leads to a 100-fold increase in Ca2+ concentrations that is needed to fully activate the channel. The following steered molecular dynamic (SMD) simulation data suggests that the mutations at 447 reduce the Ca2+ dissociation energy. Our results indicated that both the electrical property and the size of the side-chain at residue 447 have significant effects on Ca2+ dependent gating of TMEM16A. © 2015 Springer International Publishing Switzerland.


PubMed | Yanshan University, Key laboratory of Molecular Biophysics and Key Laboratory of Neural and Vascular Biology
Type: Journal Article | Journal: Journal of computer-aided molecular design | Year: 2016

Calcium-activated chloride channels (CaCCs) play vital roles in a variety of physiological processes. Transmembrane protein 16A (TMEM16A) has been confirmed as the molecular counterpart of CaCCs which greatly pushes the molecular insights of CaCCs forward. However, the detailed mechanism of Ca(2+) binding and activating the channel is still obscure. Here, we utilized a combination of computational and electrophysiological approaches to discern the molecular mechanism by which Ca(2+) regulates the gating of TMEM16A channels. The simulation results show that the first intracellular loop serves as a Ca(2+) binding site including D439, E444 and E447. The experimental results indicate that a novel residue, E447, plays key role in Ca(2+) binding. Compared with WT TMEM16A, E447Y produces a 30-fold increase in EC50 of Ca(2+) activation and leads to a 100-fold increase in Ca(2+) concentrations that is needed to fully activate the channel. The following steered molecular dynamic (SMD) simulation data suggests that the mutations at 447 reduce the Ca(2+) dissociation energy. Our results indicated that both the electrical property and the size of the side-chain at residue 447 have significant effects on Ca(2+) dependent gating of TMEM16A.

Loading Key Laboratory of Neural and Vascular Biology collaborators
Loading Key Laboratory of Neural and Vascular Biology collaborators