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Cystathionine β-synthase gene transfer into the rostral ventrolateral medulla exacerbates hypertension via nitric oxide in spontaneously hypertensive rats
S22
Abstracts/Nitric Oxide 47 (2015) S14–S60
increase independent of the sGC–cGMP pathway but activates eNOS and stimulates the NO production. 8) CCK and carbachol induced the NO production but amylase release was largely inhibited by CO. The above findings led us to conclude that the three gases interact intracellularly and modify [Ca2+]i dynamics in pancreatic acinar cells via a central role of NO. Precise investigation on this crosstalk is necessary for exploring the potential application of these gases for therapeutic usage in the treatment of pancreatic disorders such as pancreatitis. http://dx.doi.org/10.1016/j.niox.2015.02.051
PP22 The investigation of the relaxant mechanism of hydrogen sulfide in isolated mice corpus cavernosum Aydinoglu Fatma a, Ogulener Nuran b a Department of Pharmacology, Faculty of Pharmacy, Cukurova University, 01330 Adana, Turkey b Department of Pharmacology, Faculty of Medicine, Cukurova University, 01330 Adana, Turkey In the present study, the relaxant mechanism of hydrogen sulfide was investigated in isolated mice corpus cavernosum tissue. L-cysteine and sodium hydrogen sulfide (NaHS; H 2 S donor; 10−6 − 10−3) induced relaxant responses on the isolated mouse corpus cavernosum tissue which was pre-contracted by phenylephrine (5 × 10−6 M). L-cysteine-induced relaxations were significantly reduced by D,L-propargylglycine, a cystathionine gama lyase inhibitor, but were not influenced by aminooxyacetic acid, a cystathionine beta synthase inhibitor. The relaxant response to NaHS did not change in endothelium-denuded tissues. N ω -nitro-Larginine (10−4 M), a nitric oxide synthase inhibitor, ODQ (10−4 M), a guanylyl cyclase inhibitor, and combination of these drugs increased the relaxant response to NaHS. NaHS-induced relaxant response was inhibited by zaprinast (5 × 10−6 M) and sildenafil (10−6 M), phosphodiesterase inhibitors. NaHS-induced relaxation was significantly reduced by N-ethylmaleimide (2.5 × 10 −5 M) and SQ22536 (10−4 M), adenylyl cyclase inhibitors. Also, NaHS-induced relaxation was reduced in the presence of high potassium (50 mM), 4-aminopyridine, a voltage-gated potassium channel inhibitor, glibenclamide (10−5 M), a ATP-sensitive potassium channel inhibitor and barium chloride (10−5 M), an inward rectifier potassium channel inhibitor. However, NaHS-induced relaxation was not influenced by apamin (10−6 M), a small conductance calcium activated potassium channel inhibitor, charybdotoxin (10−7 M), an intermediate and large conductance calcium activated potassium channel inhibitor, and the combination of apamin and charybdotoxin. Nifedipine (10−6 M), an L-type calcium channel blocker, and atropine (10−6 M), a muscarinic receptor blocker, inhibited relaxant response to NaHS. However, NaHS-induced relaxation was not influenced by ouabain (10−4 M), a Na+/K+-ATPase inhibitor. We conclude that H2S may be produced endogenously from L-cysteine by cystathionine gama lyase enzyme in mouse corpus cavernosum tissue. The relaxant effect of H2S is endothelium-independent and H2S directly acts on smooth muscle via: i) adenylyl cyclase/cAMP, ii) potassium channels, iii) L-type calcium channel and iv) muscarinic receptors, and this relaxant effect may be suppressed by NO/sGMP. Keywords: Corpus cavernosum; hydrogen sulfide; L-cysteine; mice; relaxation; smooth muscle http://dx.doi.org/10.1016/j.niox.2015.02.052
PP23 Cystathionine β-synthase gene transfer into the rostral ventrolateral medulla exacerbates hypertension via nitric oxide in spontaneously hypertensive rats Xiao-Cui Duan a, Shang-Yu Liu a, Rong Guo b, Lin Xiao a, Hong-Mei Xue a, Qi Guo a, Sheng Jin a, Yu-Ming Wu a a Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, China b Dean’s Office of the Third Hospital of Hebei Medical University, Shijiazhuang, China Background: Rostral ventrolateral medulla (RVLM) plays a crucial role in the central regulation of cardiovascular functions. Cystathionine-β-synthase (CBS) is a major hydrogen sulfidegenerating enzyme that has been identified mainly in the brain. The present study was designed to examine CBS expression and determine its roles and mechanisms of regulating sympathetic outflow and blood pressure in the RVLM in spontaneously hypertensive rats (SHR). Methods and results: CBS expression was decreased in the RVLM in SHR compared to Wistar-Kyoto (WKY) rats. Accumulating evidence suggests that H2S interacts with nitric oxide (NO) to regulate cardiovascular function. Therefore, we hypothesize that the decrease in CBS expression in the RVLM may be involved in the disorder of the L-arginine/NO pathway, which subsequently affects blood pressure in SHR. Overexpression of CBS in the RVLM caused significant increases in blood pressure, heart rate and urinary norepinephrine excretion in SHR but not in WKY. Acute experiments were carried out at day 7 after gene transfer. Nitric oxide metabolite levels, neuronal nitric oxide synthase, and γ-amino butyric acid were decreased in SHR after CBS gene transfer. Furthermore, pressor responses to microinjection of NG-monomethyl-L-arginine into RVLM were blunt in SHR transfected with AdCBS compared to SHR transfected with AdEGFP. Conclusions: Overexpression of CBS in the RVLM elicits enhanced pressor responses in SHR, but not in WKY, and the nitric oxide system is involved in these effects. The results suggest that alterations of H2S signaling in the brain may be associated with the development of hypertension. Keywords: Hypertension; overexpression; cystathionine-βsynthase; hydrogen sulfide; rostral ventrolateral medulla; nitric oxide Acknowledgments: The work was supported by National Natural Science Foundation of China [Grant 31171098]; the Program for New Century Excellent Talents in University from the Education Ministry of China [Grant NCET-07–0252]; Hebei Province Funds for Distinguished Young Scientists [Grant 2010000471]. http://dx.doi.org/10.1016/j.niox.2015.02.053
PP24 Golgi stress mediates neurotoxicity in Huntington’s disease through the interaction of ACBD3 and cystathionine gamma lyase Juan I. Sbodio, Bindu D. Paul, Solomon H. Snyder The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA Golgi-specific protein acyl-CoA binding domain containing 3 (ACBD3), plays a role in the pathogenesis of Huntington’s disease, a neurodegenerative disorder caused by the expansion of CAG repeats in the protein huntingtin [1]. ACBD3, which is upregulated in HD, interacts with Rhes, a striatal-enriched protein and mutant huntingtin to increase their toxicity. Mechanisms that elicit toxicity also involve the dysregulation of the protein cystathionine gamma lyase (CSE), a biosynthetic enzyme for hydrogen sulfide (H2S) production. We
Abstracts/Nitric Oxide 47 (2015) S14–S60
increase independent of the sGC–cGMP pathway but activates eNOS and stimulates the NO production. 8) CCK and carbachol induced the NO production but amylase release was largely inhibited by CO. The above findings led us to conclude that the three gases interact intracellularly and modify [Ca2+]i dynamics in pancreatic acinar cells via a central role of NO. Precise investigation on this crosstalk is necessary for exploring the potential application of these gases for therapeutic usage in the treatment of pancreatic disorders such as pancreatitis. http://dx.doi.org/10.1016/j.niox.2015.02.051
PP22 The investigation of the relaxant mechanism of hydrogen sulfide in isolated mice corpus cavernosum Aydinoglu Fatma a, Ogulener Nuran b a Department of Pharmacology, Faculty of Pharmacy, Cukurova University, 01330 Adana, Turkey b Department of Pharmacology, Faculty of Medicine, Cukurova University, 01330 Adana, Turkey In the present study, the relaxant mechanism of hydrogen sulfide was investigated in isolated mice corpus cavernosum tissue. L-cysteine and sodium hydrogen sulfide (NaHS; H 2 S donor; 10−6 − 10−3) induced relaxant responses on the isolated mouse corpus cavernosum tissue which was pre-contracted by phenylephrine (5 × 10−6 M). L-cysteine-induced relaxations were significantly reduced by D,L-propargylglycine, a cystathionine gama lyase inhibitor, but were not influenced by aminooxyacetic acid, a cystathionine beta synthase inhibitor. The relaxant response to NaHS did not change in endothelium-denuded tissues. N ω -nitro-Larginine (10−4 M), a nitric oxide synthase inhibitor, ODQ (10−4 M), a guanylyl cyclase inhibitor, and combination of these drugs increased the relaxant response to NaHS. NaHS-induced relaxant response was inhibited by zaprinast (5 × 10−6 M) and sildenafil (10−6 M), phosphodiesterase inhibitors. NaHS-induced relaxation was significantly reduced by N-ethylmaleimide (2.5 × 10 −5 M) and SQ22536 (10−4 M), adenylyl cyclase inhibitors. Also, NaHS-induced relaxation was reduced in the presence of high potassium (50 mM), 4-aminopyridine, a voltage-gated potassium channel inhibitor, glibenclamide (10−5 M), a ATP-sensitive potassium channel inhibitor and barium chloride (10−5 M), an inward rectifier potassium channel inhibitor. However, NaHS-induced relaxation was not influenced by apamin (10−6 M), a small conductance calcium activated potassium channel inhibitor, charybdotoxin (10−7 M), an intermediate and large conductance calcium activated potassium channel inhibitor, and the combination of apamin and charybdotoxin. Nifedipine (10−6 M), an L-type calcium channel blocker, and atropine (10−6 M), a muscarinic receptor blocker, inhibited relaxant response to NaHS. However, NaHS-induced relaxation was not influenced by ouabain (10−4 M), a Na+/K+-ATPase inhibitor. We conclude that H2S may be produced endogenously from L-cysteine by cystathionine gama lyase enzyme in mouse corpus cavernosum tissue. The relaxant effect of H2S is endothelium-independent and H2S directly acts on smooth muscle via: i) adenylyl cyclase/cAMP, ii) potassium channels, iii) L-type calcium channel and iv) muscarinic receptors, and this relaxant effect may be suppressed by NO/sGMP. Keywords: Corpus cavernosum; hydrogen sulfide; L-cysteine; mice; relaxation; smooth muscle http://dx.doi.org/10.1016/j.niox.2015.02.052
PP23 Cystathionine β-synthase gene transfer into the rostral ventrolateral medulla exacerbates hypertension via nitric oxide in spontaneously hypertensive rats Xiao-Cui Duan a, Shang-Yu Liu a, Rong Guo b, Lin Xiao a, Hong-Mei Xue a, Qi Guo a, Sheng Jin a, Yu-Ming Wu a a Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, China b Dean’s Office of the Third Hospital of Hebei Medical University, Shijiazhuang, China Background: Rostral ventrolateral medulla (RVLM) plays a crucial role in the central regulation of cardiovascular functions. Cystathionine-β-synthase (CBS) is a major hydrogen sulfidegenerating enzyme that has been identified mainly in the brain. The present study was designed to examine CBS expression and determine its roles and mechanisms of regulating sympathetic outflow and blood pressure in the RVLM in spontaneously hypertensive rats (SHR). Methods and results: CBS expression was decreased in the RVLM in SHR compared to Wistar-Kyoto (WKY) rats. Accumulating evidence suggests that H2S interacts with nitric oxide (NO) to regulate cardiovascular function. Therefore, we hypothesize that the decrease in CBS expression in the RVLM may be involved in the disorder of the L-arginine/NO pathway, which subsequently affects blood pressure in SHR. Overexpression of CBS in the RVLM caused significant increases in blood pressure, heart rate and urinary norepinephrine excretion in SHR but not in WKY. Acute experiments were carried out at day 7 after gene transfer. Nitric oxide metabolite levels, neuronal nitric oxide synthase, and γ-amino butyric acid were decreased in SHR after CBS gene transfer. Furthermore, pressor responses to microinjection of NG-monomethyl-L-arginine into RVLM were blunt in SHR transfected with AdCBS compared to SHR transfected with AdEGFP. Conclusions: Overexpression of CBS in the RVLM elicits enhanced pressor responses in SHR, but not in WKY, and the nitric oxide system is involved in these effects. The results suggest that alterations of H2S signaling in the brain may be associated with the development of hypertension. Keywords: Hypertension; overexpression; cystathionine-βsynthase; hydrogen sulfide; rostral ventrolateral medulla; nitric oxide Acknowledgments: The work was supported by National Natural Science Foundation of China [Grant 31171098]; the Program for New Century Excellent Talents in University from the Education Ministry of China [Grant NCET-07–0252]; Hebei Province Funds for Distinguished Young Scientists [Grant 2010000471]. http://dx.doi.org/10.1016/j.niox.2015.02.053
PP24 Golgi stress mediates neurotoxicity in Huntington’s disease through the interaction of ACBD3 and cystathionine gamma lyase Juan I. Sbodio, Bindu D. Paul, Solomon H. Snyder The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA Golgi-specific protein acyl-CoA binding domain containing 3 (ACBD3), plays a role in the pathogenesis of Huntington’s disease, a neurodegenerative disorder caused by the expansion of CAG repeats in the protein huntingtin [1]. ACBD3, which is upregulated in HD, interacts with Rhes, a striatal-enriched protein and mutant huntingtin to increase their toxicity. Mechanisms that elicit toxicity also involve the dysregulation of the protein cystathionine gamma lyase (CSE), a biosynthetic enzyme for hydrogen sulfide (H2S) production. We