Jiehong Huang - Academia.edu (original) (raw)

Papers by Jiehong Huang

Research paper thumbnail of Hydrogen sulfide protects against the development of experimental cerebral malaria in a C57BL/6 mouse model

Molecular medicine reports, 2017

Hydrogen sulfide (H2S) has anti‑inflammatory and neuroprotective properties, particularly during ... more Hydrogen sulfide (H2S) has anti‑inflammatory and neuroprotective properties, particularly during pathological processes. Experimental cerebral malaria (ECM), which is caused by vascular leakage into the brain, is characterized by inflammation, neurological deficits and cerebral hemorrhage. The present study investigated the correlation between ECM genesis and the levels of H2S. The results indicated that the levels of H2S derived from the brain decreased over time following ECM infection, and that the low H2S bioavailability was partially caused by decreased expression of the H2S generating enzyme, cystathionine‑β‑synthase. Administration of NaHS (an exogenous donor of H2S) provided protection against ECM. NaHS inhibited the destruction of the blood brain barrier and the secretion of proinflammatory biomarkers, including interluekin‑18, matrix metalloproteinase‑9 and serum cluster of differentiation 40 into the brain during ECM. In conclusion, these results suggested that low levels...

Research paper thumbnail of Role of GPR30 in estrogen-induced prostate epithelial apoptosis and benign prostatic hyperplasia

Biochemical and biophysical research communications, Jan 12, 2017

Several studies have implicated estrogen and the estrogen receptor (ER) in the pathogenesis of be... more Several studies have implicated estrogen and the estrogen receptor (ER) in the pathogenesis of benign prostatic hyperplasia (BPH); however, the mechanism underlying this effect remains elusive. In the present study, we demonstrated that estrogen (17β-estradiol, or E2)-induced activation of the G protein-coupled receptor 30 (GPR30) triggered Ca(2+) release from the endoplasmic reticulum, increased the mitochondrial Ca(2+) concentration, and thus induced prostate epithelial cell (PEC) apoptosis. Both E2 and the GPR30-specific agonist G1 induced a transient intracellular Ca(2+) release in PECs via the phospholipase C (PLC)-inositol 1, 4, 5-triphosphate (IP3) pathway, and this was abolished by treatment with the GPR30 antagonist G15. The release of cytochrome c and activation of caspase-3 in response to GPR30 activation were observed. Data generated from the analysis of animal models and human clinical samples indicate that treatment with the GPR30 agonist relieves testosterone propiona...

Research paper thumbnail of Relaxant Effect of Sodium Tanshinone IIA Sulphonate on Mouse Tracheal Smooth Muscle

Planta medica, Jan 9, 2016

Sodium tanshinone IIA sulphonate, a water-soluble derivative of tanshinone IIA, has been proven t... more Sodium tanshinone IIA sulphonate, a water-soluble derivative of tanshinone IIA, has been proven to possess versatile biological properties, but its pharmacological effect on tracheal smooth muscle remains elusive. This paper presents a study on the relaxant effect and underlying mechanisms of sodium tanshinone IIA sulphonate on mouse tracheal smooth muscle. The relaxant effect of sodium tanshinone IIA sulphonate was evaluated in mouse tracheal rings using a mechanical recording system. Intracellular Ca(2+) concentration was measured in primary cultured tracheal smooth muscle cells using confocal imaging system. The results showed that sodium tanshinone IIA sulphonate induced dose-dependent relaxation of mouse tracheal rings in a β-adrenoceptor- and epithelium-independent manner. Pretreatment with the ATP-sensitive K(+) channel blocker glibenclamide partly attenuated the relaxation response. Administration of sodium tanshinone IIA sulphonate notably inhibited the extracellular Ca(2+)...

Research paper thumbnail of Functional expression of G protein-coupled receptor 30 in immature rat epididymal epithelium

Cell Biology International, 2016

The aim of this study is to investigate the functional role of G protein-coupled receptor 30 (GPR... more The aim of this study is to investigate the functional role of G protein-coupled receptor 30 (GPR30) in the epididymis. We found that GPR30 is expressed in the epithelium of the immature rat epididymis and is involved in chloride secretion into the caudal epididymis lumen. The short-circuit current (Isc) experiments showed that in primary cultured caudal epididymis epithelium, activation of GPR30 by its specific agonist G1 induced a mono-phasic current increase, and G15, the specific antagonist of GPR30, could completely inhibit the current induced by G1. The G1-induced Isc was largely blocked by application of the non-specific chloride channel inhibitor diphenylamine-dicarboxylic acid (DPC), or by the cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 , suggesting that the current was mainly mediated through CFTR. In addition, after stimulating GPR30 by G1, the intracellular concentration of cAMP in the epithelium was significantly increased, indicating that the cAMP signal pathway is involved and could be responsible for the CFTR activation. Finally, to further investigate the function of GPR30 in vivo, G15 was administrated into rats subcutaneously. The osmotic pressure of the micro perfusion solution from epididymis was measured and the sperms were collected. Results showed that there was an osmotic pressure increase of the perfusion solution from G15 treated rats. When the GPR30 was inhibited by G15 endogenously, the motility of sperms decreased. Our data demonstrated that GPR30 is involved in the formation of caudal epididymis fluid micro-environment thus affecting sperm motility.

Research paper thumbnail of Hydrogen Sulfide Facilitates Vaginal Lubrication by Activation of Epithelial ATP-Sensitive K(+) Channels and Cystic Fibrosis Transmembrane Conductance Regulator

The journal of sexual medicine, 2016

Hydrogen sulfide (H2S) plays a large role in female and male sexual responses characterized by a ... more Hydrogen sulfide (H2S) plays a large role in female and male sexual responses characterized by a smooth muscle relaxant effect. Moreover, H2S is a novel pro-secretory neuromodulator that modulates epithelial ion transport. However, whether H2S has a role in regulating vaginal epithelial ion transport and fluid secretion has not been extensively studied. To identify the effects of H2S on vaginal epithelial ion transport and lubrication in an exploratory investigation. The mRNA, protein expression, and localization of cystathionine γ-lyase (CSE) and H2S production in vaginal epithelium were examined by reverse transcriptase polymerase chain reaction, Western blot, H2S synthesizing activity assay, and immunohistochemistry, respectively. The effect of H2S on vaginal epithelial ion transport, vaginal fluid secretion, and ionic concentration was investigated using a short-circuit current (ISC), a measurement of vaginal lubrication, and ion chromatography, respectively. The mRNA, protein e...

Research paper thumbnail of Supplemental Data Ca2+Dependent Metarhodopsin Inactivation Mediated by Calmodulin and NINAC Myosin III

Research paper thumbnail of Activation of β-adrenergic receptors during sexual arousal facilitates vaginal lubrication by regulating vaginal epithelial Cl(-) secretion

The journal of sexual medicine, 2014

Vaginal lubrication, an indicator of sexual arousal and tissue health, increases significantly du... more Vaginal lubrication, an indicator of sexual arousal and tissue health, increases significantly during genital sexual arousal. Adrenergic alpha-receptors (AR) are an important regulator of genital physiological responses involved in mediating vascular and nonvascular smooth muscle contractility; the role of β-AR in sexual arousal, however, has not yet been investigated. The goal of this study was to reveal the functional role of β-AR in modulating vaginal lubrication during sexual arousal and the mechanisms underlying the process. The effects of adrenaline on vaginal epithelial ion transport, intracellular cyclic adenosine monophosphate (cAMP) content ([cAMP]i ), and vaginal lubrication were investigated using short-circuit current (ISC ) of rat vaginas incubated in vitro, enzyme-linked immunosorbent assay (ELISA), and measurement of vaginal lubrication in vivo, respectively. The expressions of β-AR in vaginal epithelium were analyzed by reverse transcription-polymerase chain reactio...

Research paper thumbnail of Cellular mechanism underlying hydrogen sulfide induced mouse tracheal smooth muscle relaxation: role of BKCa

European journal of pharmacology, Jan 15, 2014

Recent studies have suggested that hydrogen sulfide (H2S), an important endogenous signaling gase... more Recent studies have suggested that hydrogen sulfide (H2S), an important endogenous signaling gaseous molecule, participates in relaxation of smooth muscle. Nevertheless, the mechanism of this relaxation effect on respiratory system is still unclear. The present study aims to investigate the physiological function as well as cellular mechanism of H2S in tracheal smooth muscle. Application of the H2S donor, sodium hydrosulphide (NaHS) and the precursor of H2S, l-cysteine (l-Cys) induced mouse tracheal smooth muscle (TSM) relaxation in an epithelium-independent manner. The relaxation of TSM induced by NaHS was abrogated by iberiotoxin (IbTX), the large conductance calcium activated potassium channel (BKCa) blocker. In primary cultured mouse TSM cells, NaHS remarkably increased potassium outward currents in whole-cell patch clamp, hyperpolarized TSM cells and inhibited the calcium influx. All of these effects were significantly blocked by IbTX. Consistent with the results in vitro, admi...

Research paper thumbnail of NGF rapidly increases membrane expression of TRPV1 heat-gated ion channels

The EMBO Journal, 2005

Nociceptors, or pain-sensitive receptors, are unique among sensory receptors in that their sensit... more Nociceptors, or pain-sensitive receptors, are unique among sensory receptors in that their sensitivity is increased by noxious stimulation. This process, called sensitization or hyperalgesia, is mediated by a variety of proinflammatory factors, including bradykinin, ATP and NGF, which cause sensitization to noxious heat stimuli by enhancing the membrane current carried by the heat-and capsaicingated ion channel, TRPV1. Several different mechanisms for sensitization of TRPV1 have been proposed. Here we show that NGF, acting on the TrkA receptor, activates a signalling pathway in which PI3 kinase plays a crucial early role, with Src kinase as the downstream element which binds to and phosphorylates TRPV1. Phosphorylation of TRPV1 at a single tyrosine residue, Y200, followed by insertion of TRPV1 channels into the surface membrane, explains most of the rapid sensitizing actions of NGF. The EMBO Journal VOL 24 | NO 24 | 2005 EMBO THE EMBO JOURNAL THE EMBO JOURNAL NGF increases surface membrane TRPV1 X Zhang et al

Research paper thumbnail of Modulation of temperature-sensitive TRP channels

Seminars in Cell & Developmental Biology, 2006

Animals sense temperature--either cold or hot--by the direct activation of temperature-sensitive ... more Animals sense temperature--either cold or hot--by the direct activation of temperature-sensitive members of the TRP family of ion channels, the thermo-TRPs. To date, six TRP channels--TRPV1-4, TRPM8 and TRPA1--have been reported to be directly activated by heat and to be involved in thermosensation. Temperature sensing can be modulated by phosphorylation of intracellular residues by protein kinases or by insertion of new channels into the cell membrane. In this review we provide a brief overview of the properties of thermo-TRPs, and we summarise signalling pathways involved in their regulation.

Research paper thumbnail of Sodium Coupled Bicarbonate Influx Regulates Intracellular and Apical pH in Cultured Rat Caput Epididymal Epithelium

PLoS ONE, 2011

The epithelium lining the epididymis provides an optimal acidic fluid microenvironment in the epi... more The epithelium lining the epididymis provides an optimal acidic fluid microenvironment in the epididymal tract that enable spermatozoa to complete the maturation process. The present study aims to investigate the functional role of Na(+)/HCO(3)(-) cotransporter in the pH regulation in rat epididymis. Immunofluorescence staining of pan cytokeratin in the primary culture of rat caput epididymal epithelium showed that the system was a suitable model for investigating the function of epididymal epithelium. Intracellular and apical pH were measured using the fluorescent pH sensitive probe carboxy-seminaphthorhodafluor-4F acetoxymethyl ester (SNARF-4F) and sparklet pH electrode respectively to explore the functional role of rat epididymal epithelium. In the HEPES buffered Krebs-Henseleit (KH) solution, the intracellular pH (pHi) recovery from NH(4)Cl induced acidification in the cultured caput epididymal epithelium was completely inhibited by amiloride, the inhibitor of Na(+)/H(+) exchanger (NHE). Immediately changing of the KH solution from HEPES buffered to HCO(3)(-) buffered would cause another pHi recovery. The pHi recovery in HCO(3)(-) buffered KH solution was inhibited by 4, 4diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), the inhibitor of HCO(3)(-) transporter or by removal of extracellular Na(+). The extracellular pH measurement showed that the apical pH would increase when adding DIDS to the apical side of epididymal epithelial monolayer, however adding DIDS to the basolateral side had no effect on apical pH. The present study shows that sodium coupled bicarbonate influx regulates intracellular and apical pH in cultured caput epididymal epithelium.

Research paper thumbnail of Ca2+-Dependent Metarhodopsin Inactivation Mediated by Calmodulin and NINAC Myosin III

Neuron, 2008

Phototransduction in flies is the fastest known G protein-coupled signaling cascade, but how this... more Phototransduction in flies is the fastest known G protein-coupled signaling cascade, but how this performance is achieved remains unclear. Here, we investigate the mechanism and role of rhodopsin inactivation. We determined the lifetime of activated rhodopsin (metarhodopsin = M( *)) in whole-cell recordings from Drosophila photoreceptors by measuring the time window within which inactivating M( *) by photoreisomerization to rhodopsin could suppress responses to prior illumination. M( *) was inactivated rapidly (tau approximately 20 ms) under control conditions, but approximately 10-fold more slowly in Ca2+-free solutions. This pronounced Ca2+ dependence of M( *) inactivation was unaffected by mutations affecting phosphorylation of rhodopsin or arrestin but was abolished in mutants of calmodulin (CaM) or the CaM-binding myosin III, NINAC. This suggests a mechanism whereby Ca2+ influx acting via CaM and NINAC accelerates the binding of arrestin to M( *). Our results indicate that this strategy promotes quantum efficiency, temporal resolution, and fidelity of visual signaling.

Research paper thumbnail of Light-Dependent Modulation of Shab Channels via Phosphoinositide Depletion in Drosophila Photoreceptors

Neuron, 2008

The Drosophila phototransduction cascade transforms light into depolarizations that are further s... more The Drosophila phototransduction cascade transforms light into depolarizations that are further shaped by activation of voltage-dependent K+ (Kv) channels. In whole-cell recordings of isolated photoreceptors, we show that light selectively modulated the delayed rectifier (Shab) current. Shab currents were increased by light with similar kinetics to the light-induced current itself (latency approximately 20 ms), recovering to control values with a t(1/2) of approximately 60 s in darkness. Genetic disruption of PLCbeta4, responsible for light-induced PIP(2) hydrolysis, abolished this light-dependent modulation. In mutants of CDP-diaclyglycerol synthase (cds(1)), required for PIP(2) resynthesis, the modulation became irreversible, but exogenously applied PIP(2) restored reversibility. The modulation was accurately and reversibly mimicked by application of PIP(2) to heterologously expressed Shab channels in excised inside-out patches. The results indicate a functionally implemented mechanism of Kv channel modulation by PIP(2) in photoreceptors, which enables light-dependent regulation of signal processing by direct coupling to the phototransduction cascade.

Research paper thumbnail of Tyrosine phosphorylation modulates store-operated calcium entry in cultured rat epididymal basal cells

Journal of Cellular Physiology, 2011

Store-operated calcium entry (SOCE) is essential for many cellular processes. In this study, we i... more Store-operated calcium entry (SOCE) is essential for many cellular processes. In this study, we investigated modulation of SOCE by tyrosine phosphorylation in rat epididymal basal cells. The intracellular Ca(2+) ([Ca(2+)]i) measurement showed that SOCE occurred in rat epididymal basal cells by pretreating the cells with thapsigargin (Tg), the inhibitor of sarco-endoplasmic reticulum Ca(2+)-ATPase. To identify the role of Ca(2+) channels in this response, we examined the effects of transient receptor potential canonical channel blockers 2-aminoethoxydiphenyl borate (2-APB), 1-[β-[3-(4-methoxyphenyl)pro-poxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride(SKF96365), Gd(3+), and non-selective cation channel blocker Ni(2+) respectively on SOCE and found that these blockers could inhibit the Ca(2+) influx to different extent. Furthermore, we studied the regulation of SOCE by tyrosine kinase pathway. The inhibitor of tyrosine kinase genistein remarkably suppressed the SOCE response, whereas sodium orthovanadate, the inhibitor of tyrosine phosphatase, greatly enhanced it. The results suggest that tyrosine kinase pathway plays a significant role in the initiation of SOCE and positively modulates SOCE in epididymal basal cells.

Research paper thumbnail of Activation of TRP Channels by Protons and Phosphoinositide Depletion in Drosophila Photoreceptors

Current Biology, 2010

Background: Phototransduction in microvillar photoreceptors is mediated via G protein-coupled pho... more Background: Phototransduction in microvillar photoreceptors is mediated via G protein-coupled phospholipase C (PLC), but how PLC activation leads to the opening of the light-sensitive TRPC channels (TRP and TRPL) remains unresolved. In Drosophila, InsP 3 appears not to be involved, and recent studies have implicated lipid products of PLC activity, e.g., diacylglycerol, its metabolites, or the reduction in PIP 2 . The fact that hydrolysis of the phosphodiester bond in PIP 2 by PLC also releases a proton is seldom recognized and has neither been measured in vivo nor implicated previously in a signaling context. Results: Following depletion of PIP 2 and other phosphoinositides by a variety of experimental manipulations, the lightsensitive channels in Drosophila photoreceptors become remarkably sensitive to rapid and reversible activation by the lipophilic protonophore 2-4 dinitrophenol in a pH-dependent manner. We further show that light induces a rapid (<10 ms) acidification originating in the microvilli, which is eliminated in mutants of PLC, and that heterologously expressed TRPL channels are activated by acidification of the cytosolic surface of inside-out patches. Conclusions: Our results indicate that a combination of phosphoinositide depletion and acidification of the membrane/ boundary layer is sufficient to activate the light-sensitive channels. Together with the demonstration of light-induced, PLCdependent acidification, this suggests that excitation in Drosophila photoreceptors may be mediated by PLC's dual action of phosphoinositide depletion and proton release.

Research paper thumbnail of Involvement of TRPV2 in sexual excitation transduction in rat penile peripheral nerve fibers

Cell Biology International, 2010

Research paper thumbnail of Na + reabsorption in rat vaginal epithelium via epithelial sodium channel

Cell Biology International, 2010

Research paper thumbnail of Regulation of the vaginal epithelium pH by extracellular ATP via CFTR

Cell Biology International, 2010

Research paper thumbnail of Cellular mechanisms underlying the duel effect of formaldehyde on mouse airway epithelium

Cell Biology International, 2010

Research paper thumbnail of Inflammatory Pain: The Cellular Basis of Heat Hyperalgesia

Current Neuropharmacology, 2006

Injury or inflammation release a range of inflammatory mediators that increase the sensitivity of... more Injury or inflammation release a range of inflammatory mediators that increase the sensitivity of sensory neurons to noxious thermal or mechanical stimuli. The heat-and capsaicin-gated channel TRPV1, which is an important detector of multiple noxious stimuli, plays a critical role in the development of thermal hyperalgesia induced by a wide range of inflammatory mediators. We review here recent findings on the molecular mechanisms of sensitisation of TRPV1 by inflammatory mediators, including bradykinin, ATP, NGF and prostaglandins. We describe the signalling pathways believed to be involved in the potentiation of TRPV1, and our current understanding of how inflammatory mediators couple to these pathways.

Research paper thumbnail of Hydrogen sulfide protects against the development of experimental cerebral malaria in a C57BL/6 mouse model

Molecular medicine reports, 2017

Hydrogen sulfide (H2S) has anti‑inflammatory and neuroprotective properties, particularly during ... more Hydrogen sulfide (H2S) has anti‑inflammatory and neuroprotective properties, particularly during pathological processes. Experimental cerebral malaria (ECM), which is caused by vascular leakage into the brain, is characterized by inflammation, neurological deficits and cerebral hemorrhage. The present study investigated the correlation between ECM genesis and the levels of H2S. The results indicated that the levels of H2S derived from the brain decreased over time following ECM infection, and that the low H2S bioavailability was partially caused by decreased expression of the H2S generating enzyme, cystathionine‑β‑synthase. Administration of NaHS (an exogenous donor of H2S) provided protection against ECM. NaHS inhibited the destruction of the blood brain barrier and the secretion of proinflammatory biomarkers, including interluekin‑18, matrix metalloproteinase‑9 and serum cluster of differentiation 40 into the brain during ECM. In conclusion, these results suggested that low levels...

Research paper thumbnail of Role of GPR30 in estrogen-induced prostate epithelial apoptosis and benign prostatic hyperplasia

Biochemical and biophysical research communications, Jan 12, 2017

Several studies have implicated estrogen and the estrogen receptor (ER) in the pathogenesis of be... more Several studies have implicated estrogen and the estrogen receptor (ER) in the pathogenesis of benign prostatic hyperplasia (BPH); however, the mechanism underlying this effect remains elusive. In the present study, we demonstrated that estrogen (17β-estradiol, or E2)-induced activation of the G protein-coupled receptor 30 (GPR30) triggered Ca(2+) release from the endoplasmic reticulum, increased the mitochondrial Ca(2+) concentration, and thus induced prostate epithelial cell (PEC) apoptosis. Both E2 and the GPR30-specific agonist G1 induced a transient intracellular Ca(2+) release in PECs via the phospholipase C (PLC)-inositol 1, 4, 5-triphosphate (IP3) pathway, and this was abolished by treatment with the GPR30 antagonist G15. The release of cytochrome c and activation of caspase-3 in response to GPR30 activation were observed. Data generated from the analysis of animal models and human clinical samples indicate that treatment with the GPR30 agonist relieves testosterone propiona...

Research paper thumbnail of Relaxant Effect of Sodium Tanshinone IIA Sulphonate on Mouse Tracheal Smooth Muscle

Planta medica, Jan 9, 2016

Sodium tanshinone IIA sulphonate, a water-soluble derivative of tanshinone IIA, has been proven t... more Sodium tanshinone IIA sulphonate, a water-soluble derivative of tanshinone IIA, has been proven to possess versatile biological properties, but its pharmacological effect on tracheal smooth muscle remains elusive. This paper presents a study on the relaxant effect and underlying mechanisms of sodium tanshinone IIA sulphonate on mouse tracheal smooth muscle. The relaxant effect of sodium tanshinone IIA sulphonate was evaluated in mouse tracheal rings using a mechanical recording system. Intracellular Ca(2+) concentration was measured in primary cultured tracheal smooth muscle cells using confocal imaging system. The results showed that sodium tanshinone IIA sulphonate induced dose-dependent relaxation of mouse tracheal rings in a β-adrenoceptor- and epithelium-independent manner. Pretreatment with the ATP-sensitive K(+) channel blocker glibenclamide partly attenuated the relaxation response. Administration of sodium tanshinone IIA sulphonate notably inhibited the extracellular Ca(2+)...

Research paper thumbnail of Functional expression of G protein-coupled receptor 30 in immature rat epididymal epithelium

Cell Biology International, 2016

The aim of this study is to investigate the functional role of G protein-coupled receptor 30 (GPR... more The aim of this study is to investigate the functional role of G protein-coupled receptor 30 (GPR30) in the epididymis. We found that GPR30 is expressed in the epithelium of the immature rat epididymis and is involved in chloride secretion into the caudal epididymis lumen. The short-circuit current (Isc) experiments showed that in primary cultured caudal epididymis epithelium, activation of GPR30 by its specific agonist G1 induced a mono-phasic current increase, and G15, the specific antagonist of GPR30, could completely inhibit the current induced by G1. The G1-induced Isc was largely blocked by application of the non-specific chloride channel inhibitor diphenylamine-dicarboxylic acid (DPC), or by the cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor CFTRinh-172 , suggesting that the current was mainly mediated through CFTR. In addition, after stimulating GPR30 by G1, the intracellular concentration of cAMP in the epithelium was significantly increased, indicating that the cAMP signal pathway is involved and could be responsible for the CFTR activation. Finally, to further investigate the function of GPR30 in vivo, G15 was administrated into rats subcutaneously. The osmotic pressure of the micro perfusion solution from epididymis was measured and the sperms were collected. Results showed that there was an osmotic pressure increase of the perfusion solution from G15 treated rats. When the GPR30 was inhibited by G15 endogenously, the motility of sperms decreased. Our data demonstrated that GPR30 is involved in the formation of caudal epididymis fluid micro-environment thus affecting sperm motility.

Research paper thumbnail of Hydrogen Sulfide Facilitates Vaginal Lubrication by Activation of Epithelial ATP-Sensitive K(+) Channels and Cystic Fibrosis Transmembrane Conductance Regulator

The journal of sexual medicine, 2016

Hydrogen sulfide (H2S) plays a large role in female and male sexual responses characterized by a ... more Hydrogen sulfide (H2S) plays a large role in female and male sexual responses characterized by a smooth muscle relaxant effect. Moreover, H2S is a novel pro-secretory neuromodulator that modulates epithelial ion transport. However, whether H2S has a role in regulating vaginal epithelial ion transport and fluid secretion has not been extensively studied. To identify the effects of H2S on vaginal epithelial ion transport and lubrication in an exploratory investigation. The mRNA, protein expression, and localization of cystathionine γ-lyase (CSE) and H2S production in vaginal epithelium were examined by reverse transcriptase polymerase chain reaction, Western blot, H2S synthesizing activity assay, and immunohistochemistry, respectively. The effect of H2S on vaginal epithelial ion transport, vaginal fluid secretion, and ionic concentration was investigated using a short-circuit current (ISC), a measurement of vaginal lubrication, and ion chromatography, respectively. The mRNA, protein e...

Research paper thumbnail of Supplemental Data Ca2+Dependent Metarhodopsin Inactivation Mediated by Calmodulin and NINAC Myosin III

Research paper thumbnail of Activation of β-adrenergic receptors during sexual arousal facilitates vaginal lubrication by regulating vaginal epithelial Cl(-) secretion

The journal of sexual medicine, 2014

Vaginal lubrication, an indicator of sexual arousal and tissue health, increases significantly du... more Vaginal lubrication, an indicator of sexual arousal and tissue health, increases significantly during genital sexual arousal. Adrenergic alpha-receptors (AR) are an important regulator of genital physiological responses involved in mediating vascular and nonvascular smooth muscle contractility; the role of β-AR in sexual arousal, however, has not yet been investigated. The goal of this study was to reveal the functional role of β-AR in modulating vaginal lubrication during sexual arousal and the mechanisms underlying the process. The effects of adrenaline on vaginal epithelial ion transport, intracellular cyclic adenosine monophosphate (cAMP) content ([cAMP]i ), and vaginal lubrication were investigated using short-circuit current (ISC ) of rat vaginas incubated in vitro, enzyme-linked immunosorbent assay (ELISA), and measurement of vaginal lubrication in vivo, respectively. The expressions of β-AR in vaginal epithelium were analyzed by reverse transcription-polymerase chain reactio...

Research paper thumbnail of Cellular mechanism underlying hydrogen sulfide induced mouse tracheal smooth muscle relaxation: role of BKCa

European journal of pharmacology, Jan 15, 2014

Recent studies have suggested that hydrogen sulfide (H2S), an important endogenous signaling gase... more Recent studies have suggested that hydrogen sulfide (H2S), an important endogenous signaling gaseous molecule, participates in relaxation of smooth muscle. Nevertheless, the mechanism of this relaxation effect on respiratory system is still unclear. The present study aims to investigate the physiological function as well as cellular mechanism of H2S in tracheal smooth muscle. Application of the H2S donor, sodium hydrosulphide (NaHS) and the precursor of H2S, l-cysteine (l-Cys) induced mouse tracheal smooth muscle (TSM) relaxation in an epithelium-independent manner. The relaxation of TSM induced by NaHS was abrogated by iberiotoxin (IbTX), the large conductance calcium activated potassium channel (BKCa) blocker. In primary cultured mouse TSM cells, NaHS remarkably increased potassium outward currents in whole-cell patch clamp, hyperpolarized TSM cells and inhibited the calcium influx. All of these effects were significantly blocked by IbTX. Consistent with the results in vitro, admi...

Research paper thumbnail of NGF rapidly increases membrane expression of TRPV1 heat-gated ion channels

The EMBO Journal, 2005

Nociceptors, or pain-sensitive receptors, are unique among sensory receptors in that their sensit... more Nociceptors, or pain-sensitive receptors, are unique among sensory receptors in that their sensitivity is increased by noxious stimulation. This process, called sensitization or hyperalgesia, is mediated by a variety of proinflammatory factors, including bradykinin, ATP and NGF, which cause sensitization to noxious heat stimuli by enhancing the membrane current carried by the heat-and capsaicingated ion channel, TRPV1. Several different mechanisms for sensitization of TRPV1 have been proposed. Here we show that NGF, acting on the TrkA receptor, activates a signalling pathway in which PI3 kinase plays a crucial early role, with Src kinase as the downstream element which binds to and phosphorylates TRPV1. Phosphorylation of TRPV1 at a single tyrosine residue, Y200, followed by insertion of TRPV1 channels into the surface membrane, explains most of the rapid sensitizing actions of NGF. The EMBO Journal VOL 24 | NO 24 | 2005 EMBO THE EMBO JOURNAL THE EMBO JOURNAL NGF increases surface membrane TRPV1 X Zhang et al

Research paper thumbnail of Modulation of temperature-sensitive TRP channels

Seminars in Cell & Developmental Biology, 2006

Animals sense temperature--either cold or hot--by the direct activation of temperature-sensitive ... more Animals sense temperature--either cold or hot--by the direct activation of temperature-sensitive members of the TRP family of ion channels, the thermo-TRPs. To date, six TRP channels--TRPV1-4, TRPM8 and TRPA1--have been reported to be directly activated by heat and to be involved in thermosensation. Temperature sensing can be modulated by phosphorylation of intracellular residues by protein kinases or by insertion of new channels into the cell membrane. In this review we provide a brief overview of the properties of thermo-TRPs, and we summarise signalling pathways involved in their regulation.

Research paper thumbnail of Sodium Coupled Bicarbonate Influx Regulates Intracellular and Apical pH in Cultured Rat Caput Epididymal Epithelium

PLoS ONE, 2011

The epithelium lining the epididymis provides an optimal acidic fluid microenvironment in the epi... more The epithelium lining the epididymis provides an optimal acidic fluid microenvironment in the epididymal tract that enable spermatozoa to complete the maturation process. The present study aims to investigate the functional role of Na(+)/HCO(3)(-) cotransporter in the pH regulation in rat epididymis. Immunofluorescence staining of pan cytokeratin in the primary culture of rat caput epididymal epithelium showed that the system was a suitable model for investigating the function of epididymal epithelium. Intracellular and apical pH were measured using the fluorescent pH sensitive probe carboxy-seminaphthorhodafluor-4F acetoxymethyl ester (SNARF-4F) and sparklet pH electrode respectively to explore the functional role of rat epididymal epithelium. In the HEPES buffered Krebs-Henseleit (KH) solution, the intracellular pH (pHi) recovery from NH(4)Cl induced acidification in the cultured caput epididymal epithelium was completely inhibited by amiloride, the inhibitor of Na(+)/H(+) exchanger (NHE). Immediately changing of the KH solution from HEPES buffered to HCO(3)(-) buffered would cause another pHi recovery. The pHi recovery in HCO(3)(-) buffered KH solution was inhibited by 4, 4diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), the inhibitor of HCO(3)(-) transporter or by removal of extracellular Na(+). The extracellular pH measurement showed that the apical pH would increase when adding DIDS to the apical side of epididymal epithelial monolayer, however adding DIDS to the basolateral side had no effect on apical pH. The present study shows that sodium coupled bicarbonate influx regulates intracellular and apical pH in cultured caput epididymal epithelium.

Research paper thumbnail of Ca2+-Dependent Metarhodopsin Inactivation Mediated by Calmodulin and NINAC Myosin III

Neuron, 2008

Phototransduction in flies is the fastest known G protein-coupled signaling cascade, but how this... more Phototransduction in flies is the fastest known G protein-coupled signaling cascade, but how this performance is achieved remains unclear. Here, we investigate the mechanism and role of rhodopsin inactivation. We determined the lifetime of activated rhodopsin (metarhodopsin = M( *)) in whole-cell recordings from Drosophila photoreceptors by measuring the time window within which inactivating M( *) by photoreisomerization to rhodopsin could suppress responses to prior illumination. M( *) was inactivated rapidly (tau approximately 20 ms) under control conditions, but approximately 10-fold more slowly in Ca2+-free solutions. This pronounced Ca2+ dependence of M( *) inactivation was unaffected by mutations affecting phosphorylation of rhodopsin or arrestin but was abolished in mutants of calmodulin (CaM) or the CaM-binding myosin III, NINAC. This suggests a mechanism whereby Ca2+ influx acting via CaM and NINAC accelerates the binding of arrestin to M( *). Our results indicate that this strategy promotes quantum efficiency, temporal resolution, and fidelity of visual signaling.

Research paper thumbnail of Light-Dependent Modulation of Shab Channels via Phosphoinositide Depletion in Drosophila Photoreceptors

Neuron, 2008

The Drosophila phototransduction cascade transforms light into depolarizations that are further s... more The Drosophila phototransduction cascade transforms light into depolarizations that are further shaped by activation of voltage-dependent K+ (Kv) channels. In whole-cell recordings of isolated photoreceptors, we show that light selectively modulated the delayed rectifier (Shab) current. Shab currents were increased by light with similar kinetics to the light-induced current itself (latency approximately 20 ms), recovering to control values with a t(1/2) of approximately 60 s in darkness. Genetic disruption of PLCbeta4, responsible for light-induced PIP(2) hydrolysis, abolished this light-dependent modulation. In mutants of CDP-diaclyglycerol synthase (cds(1)), required for PIP(2) resynthesis, the modulation became irreversible, but exogenously applied PIP(2) restored reversibility. The modulation was accurately and reversibly mimicked by application of PIP(2) to heterologously expressed Shab channels in excised inside-out patches. The results indicate a functionally implemented mechanism of Kv channel modulation by PIP(2) in photoreceptors, which enables light-dependent regulation of signal processing by direct coupling to the phototransduction cascade.

Research paper thumbnail of Tyrosine phosphorylation modulates store-operated calcium entry in cultured rat epididymal basal cells

Journal of Cellular Physiology, 2011

Store-operated calcium entry (SOCE) is essential for many cellular processes. In this study, we i... more Store-operated calcium entry (SOCE) is essential for many cellular processes. In this study, we investigated modulation of SOCE by tyrosine phosphorylation in rat epididymal basal cells. The intracellular Ca(2+) ([Ca(2+)]i) measurement showed that SOCE occurred in rat epididymal basal cells by pretreating the cells with thapsigargin (Tg), the inhibitor of sarco-endoplasmic reticulum Ca(2+)-ATPase. To identify the role of Ca(2+) channels in this response, we examined the effects of transient receptor potential canonical channel blockers 2-aminoethoxydiphenyl borate (2-APB), 1-[β-[3-(4-methoxyphenyl)pro-poxy]-4-methoxyphenethyl]-1H-imidazole hydrochloride(SKF96365), Gd(3+), and non-selective cation channel blocker Ni(2+) respectively on SOCE and found that these blockers could inhibit the Ca(2+) influx to different extent. Furthermore, we studied the regulation of SOCE by tyrosine kinase pathway. The inhibitor of tyrosine kinase genistein remarkably suppressed the SOCE response, whereas sodium orthovanadate, the inhibitor of tyrosine phosphatase, greatly enhanced it. The results suggest that tyrosine kinase pathway plays a significant role in the initiation of SOCE and positively modulates SOCE in epididymal basal cells.

Research paper thumbnail of Activation of TRP Channels by Protons and Phosphoinositide Depletion in Drosophila Photoreceptors

Current Biology, 2010

Background: Phototransduction in microvillar photoreceptors is mediated via G protein-coupled pho... more Background: Phototransduction in microvillar photoreceptors is mediated via G protein-coupled phospholipase C (PLC), but how PLC activation leads to the opening of the light-sensitive TRPC channels (TRP and TRPL) remains unresolved. In Drosophila, InsP 3 appears not to be involved, and recent studies have implicated lipid products of PLC activity, e.g., diacylglycerol, its metabolites, or the reduction in PIP 2 . The fact that hydrolysis of the phosphodiester bond in PIP 2 by PLC also releases a proton is seldom recognized and has neither been measured in vivo nor implicated previously in a signaling context. Results: Following depletion of PIP 2 and other phosphoinositides by a variety of experimental manipulations, the lightsensitive channels in Drosophila photoreceptors become remarkably sensitive to rapid and reversible activation by the lipophilic protonophore 2-4 dinitrophenol in a pH-dependent manner. We further show that light induces a rapid (<10 ms) acidification originating in the microvilli, which is eliminated in mutants of PLC, and that heterologously expressed TRPL channels are activated by acidification of the cytosolic surface of inside-out patches. Conclusions: Our results indicate that a combination of phosphoinositide depletion and acidification of the membrane/ boundary layer is sufficient to activate the light-sensitive channels. Together with the demonstration of light-induced, PLCdependent acidification, this suggests that excitation in Drosophila photoreceptors may be mediated by PLC's dual action of phosphoinositide depletion and proton release.

Research paper thumbnail of Involvement of TRPV2 in sexual excitation transduction in rat penile peripheral nerve fibers

Cell Biology International, 2010

Research paper thumbnail of Na + reabsorption in rat vaginal epithelium via epithelial sodium channel

Cell Biology International, 2010

Research paper thumbnail of Regulation of the vaginal epithelium pH by extracellular ATP via CFTR

Cell Biology International, 2010

Research paper thumbnail of Cellular mechanisms underlying the duel effect of formaldehyde on mouse airway epithelium

Cell Biology International, 2010

Research paper thumbnail of Inflammatory Pain: The Cellular Basis of Heat Hyperalgesia

Current Neuropharmacology, 2006

Injury or inflammation release a range of inflammatory mediators that increase the sensitivity of... more Injury or inflammation release a range of inflammatory mediators that increase the sensitivity of sensory neurons to noxious thermal or mechanical stimuli. The heat-and capsaicin-gated channel TRPV1, which is an important detector of multiple noxious stimuli, plays a critical role in the development of thermal hyperalgesia induced by a wide range of inflammatory mediators. We review here recent findings on the molecular mechanisms of sensitisation of TRPV1 by inflammatory mediators, including bradykinin, ATP, NGF and prostaglandins. We describe the signalling pathways believed to be involved in the potentiation of TRPV1, and our current understanding of how inflammatory mediators couple to these pathways.