研究等業績 - 原著論文 - 渡邊 博之
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Successful outcome in a pregnant woman with isolated noncompaction of the left ventricular myocardium.
Yoshiko Munehisa, Hiroyuki Watanabe, Toshimitsu Kosaka, Akinori Kimura, Hiroshi Ito
Internal medicine (Tokyo, Japan) 46 ( 6 ) 285 - 9 2007年06月 [査読有り]
研究論文（学術雑誌）
A 24-year-old pregnant woman was referred to our hospital for the evaluation of her cardiac function. An electrocardiogram showed Wolff-Parkinson-White syndrome. Echocardiography revealed prominent trabeculation and deep intertrabecular recesses at the left ventricular apex and mid-portion of the inferior and lateral wall, with an impaired ejection fraction. She was diagnosed as having an isolated noncompaction of the ventricular myocardium (INVM). As the pregnancy progressed, severe restrictive hemodynamics became apparent. In consideration of the fetal growth, we decided to deliver the fetus by cesarean section at 32 weeks gestation; the patient successfully delivered a female infant. Interestingly, echocardiography demonstrated INVM in both the child and mother. This report is the first description of a successful pregnancy in a patient with familial INVM.
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Essential role of the N-terminus of murine Orai1 in store-operated Ca2+ entry.
Yoichiro Takahashi, Manabu Murakami, Hiroyuki Watanabe, Hitoshi Hasegawa, Takayoshi Ohba, Yoshiko Munehisa, Kiyoshi Nobori, Kyoichi Ono, Toshihiko Iijima, Hiroshi Ito
Biochemical and biophysical research communications 356 ( 1 ) 45 - 52 2007年04月 [査読有り]
研究論文（学術雑誌）
Store-operated Ca(2+) entry (SOCE) is a physiologically important process that is triggered by intracellular Ca(2+) depletion. Recently, human Orai1 (the channel-forming subunit) and STIM1 (the calcium sensor) were identified as essential molecules for SOCE. Here, we report the cloning and functional analysis of three murine orthologs of Orai1, termed Orai1, 2, and 3. Among the genes identified, Orai1 contains a distinctive proline- and arginine-rich N-terminal cytoplasmic sequence. Co-expression of STIM1 with Orai1 produced a marked effect on SOCE, while co-expression with Orai2 or Orai3 had little effect. Expression of Orai1 without its N-terminal tail had a marginal effect on SOCE, while chimeric Orai2 containing the Orai1 N-terminus produced a marked increase in SOCE. In addition, a truncated version of Orai1 containing the N-terminus without the pore-forming transmembrane domain had a dominant negative effect on SOCE. These results reveal the essential role of Orai1 and its N-terminal sequence in SOCE.
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Modified sympathetic regulation in N-type calcium channel null-mouse.
Manabu Murakami, Takayoshi Ohba, Tsai-Wen Wu, Susumu Fujisawa, Takashi Suzuki, Yoichiro Takahashi, Eiki Takahashi, Hiroyuki Watanabe, Ichiro Miyoshi, Kyoichi Ono, Hironobu Sasano, Hiroshi Ito, Toshihiko Iijima
Biochemical and biophysical research communications 354 ( 4 ) 1016 - 20 2007年03月 [査読有り]
研究論文（学術雑誌）
To elucidate the physiological importance of neuronal (N)-type calcium channels in sympathetic controls, we analyzed N-type channel-deficient (NKO) mice. Immunoprecipitation analysis revealed increased interaction between beta3 (a major accessory subunit of N-type channels) and R-type channel-forming CaV2.3 in NKO mice. R-R intervals in NKO ECG recordings were elongated and fluctuating, suggesting disturbed sympathetic tonus. N-type channel inhibitors elongated the R-R interval in control mice, whereas R-type channel blocking with SNX-482 significantly affected NKO but not control mice, indicating a compensatory role for R-type channels. Echocardiography and Langendorff heart analysis confirmed a major role for R-type channels in NKO mice. Combined, our biochemical and physiological analyses strongly suggest that the remaining sympathetic tonus in NKO mice is dependent on R-type calcium channels.
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Upregulation of TRPC1 in the development of cardiac hypertrophy
Ohba T， Watanabe H et. Al
JMCC 42 ( 3 ) 498 - 507 2007年03月 [査読有り]
研究論文（学術雑誌） 国内共著
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Involvement of transient receptor potential canonical 1 (TRPC1) in angiotensin II-induced vascular smooth muscle cell hypertrophy
Takahashi Y， Watanabe H et. Al
Atherosclerosis 2007年01月 [査読有り]
研究論文（学術雑誌） 国内共著
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Regulatory role of neuron-restrictive silencing factor in expression of TRPC1.
Takayoshi Ohba, Hiroyuki Watanabe, Yoichiro Takahashi, Takashi Suzuki, Ichiro Miyoshi, Shinnsuke Nakayama, Eisaku Satoh, Kenji Iino, Hironobu Sasano, Yasuo Mori, Sadao Kuromitsu, Keiichi Imagawa, Yoshihiko Saito, Toshihiko Iijima, Hiroshi Ito, Manabu Murakami
Biochemical and biophysical research communications 351 ( 3 ) 764 - 70 2006年12月 [査読有り]
研究論文（学術雑誌）
Neuron-restrictive silencer factor (NRSF) binds its consensus element to repress the transcription of various genes. The dominant-negative form (dnNRSF) has a hypertrophic effect on cardiogenesis through an unidentified mechanism. We examined the involvement of transient receptor potential (TRP) channel proteins, using transgenic mice overexpressing dnNRSF (dnNRSF mice). Electrophoretic mobility-shift assays revealed an interaction between NRSF and a neuron-restrictive silencer element-like sequence in intron 4 of TRPC1 genomic DNA. According to RT-PCR and Western analyses, TRPC1 was up-regulated in dnNRSF mouse heart. Transient overexpression of TRPC1 in HEK 293T cells increased the activity of the nuclear factor in activated T cells (NFAT) promoter and stimulated store-operated Ca(2+) channel (SOCC)-mediated Ca(2+) entry. Transfection of TRPC1 into primary cardiomyocytes increased NFAT activity, indicating a major role for TRPC1 in NFAT activation. Our findings strongly suggest that NRSF regulates TRP1 gene expression and causes changes in the levels of calcium entry through SOCCs.
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Identification of a cardiac isoform of the murine calcium channel alpha1C (Cav1.2-a) subunit and its preferential binding with the beta2 subunit.
Manabu Murakami, Takayoshi Ohba, Yoichiro Takahashi, Hiroyuki Watanabe, Ichiro Miyoshi, Shinsuke Nakayama, Kyoichi Ono, Hiroshi Ito, Toshihiko Iijima
Journal of molecular and cellular cardiology 41 ( 1 ) 115 - 25 2006年07月 [査読有り]
研究論文（学術雑誌）
We describe a cardiac muscle isoform of the voltage-dependent calcium channel alpha1 subunit, which corresponds to the rabbit ortholog of alpha1C-a (Cav1.2a). We also cloned smooth muscle isoforms alpha1C-b (Cav1.2b) and alpha1C-d (Cav1.2d). Differences among these three isoforms lie within the N-terminal region (exon 1A or 1B), the sixth transmembrane segment of domain I (exon 8A or 8B), and the use of exon 10, which forms the intracellular loop between transmembrane domains I and II. Two-hybrid analysis revealed interactions among the three alpha1 isoforms and beta subunits. In vitro overlay and immunoprecipitation analyses revealed preferential binding between alpha1C-a and beta2, which is also expressed at a high level in the heart.
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Increased expression of transient receptor potential C1 in rats with hypertensive hypertrophy
Takayoshi Ohba, Hiroyuki Watanabe, Manabu Murakami,Yoichiro Tkahashi,Hiroshi Ito
秋田医学 32 201 - 207 2006年03月 [査読有り]
研究論文（学術雑誌）
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The effect of Unoprostone on store operated Ca entry in human aortic smooth muscle cells
Watanabe Akiko, Watanabe Hiroyuki, Ono Kyoichi, Ohba Takayoshi, Murakami Manabu, Hasegawa Hitoshi, Sasaki Masahiro, Iijima Toshihiko, Yoshitomi Takeshi, Ito Hiroshi
秋田医学 32 ( 1 ) 7 - 14 2005年05月 [査読有り]
研究論文（学術雑誌）
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Genomic organization and functional analysis of murine PKD2L1.
Manabu Murakami, Takayoshi Ohba, Feng Xu, Seiji Shida, Eisaku Satoh, Kyoichi Ono, Ichiro Miyoshi, Hiroyuki Watanabe, Hiroshi Ito, Toshihiko Iijima
The Journal of biological chemistry 280 ( 7 ) 5626 - 35 2005年02月 [査読有り]
研究論文（学術雑誌）
Mutations in genes that encode polycystins 1 or 2 cause polycystic kidney disease (PKD). Here, we report the genomic organization and functional expression of murine orthologue of human polycystin-2L1 (PKD2L1). The murine PKD2L1 gene comprises 15 exons in chromosome 19C3. Coexpression of PKD2L1 together with polycystin-1 (PKD1) resulted in the expression of PKD2L1 channels on the cell surface, whereas PKD2L1 expressed alone was retained within the endoplasmic reticulum (ER). This suggested that interaction between PKD1 and PKD2L1 is essential for PKD2L1 trafficking and channel formation. Deletion analysis at the cytoplasmic tail of PKD2L1 revealed that the coiled-coil domain was important for trafficking by PKD1. Mutagenesis within two newly identified ER retention signal-like amino acid sequences caused PKD2L1 to be expressed at the cell surface. This indicated that the coiled-coil domain was responsible for retaining PKD2L1 within the ER. Functional analysis of murine PKD2L1 expressed in HEK 293 cells was undertaken using calcium imaging. Coexpression of PKD1 and PKD2L1 resulted in the formation of functional cation channels that were opened by hypo-osmotic stimulation, whereas neither molecule formed functional channels when expressed alone. We conclude that PKD2L1 forms functional cation channels on the plasma membrane by interacting with PKD1. These findings raise the possibility that PKD2L1 represents the third genetic locus that is responsible for PKD.
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Low Molecular Weight Heparin Prevents Cardiovascular Remodeling Induced by the Long-Term Inhibition of Nitric Oxide Synthase with N-Nitro-L-Arginine Methyl Ester in Rat Hearts
HASEGAWA Hitoshi,SAITO Takashi,FUJIWARA Yoshimasa,KUROKAWA Fukiko,WATANABE hiroyuki
秋田医学 31 221 - 230 2004年12月 [査読有り]
研究論文（学術雑誌）
To evaluate the effect of low molecular weight heparin (LMWH) oncardiovascular remodeling induced by long term inhibition of nitric oxide synthase withN-nitro-L-arginine methyl ester (L-NAME), 40 male Sprague-Dawley rats were randomlydivided into four groups: the control group (n=10) that received 0.9% saltsolution; the L-NAME group (n=10) that received 30 mg/kg/day of L-NAME, theLMWH3000 group (n=10) that received 30 mg/kg/day of L-NAME and 4 mg/kg/dayof LMWH (molecular weight (M.W.) of 3000) and the LMWH6000 group (n= 10)that received 30 mg/kg/day of L-NAME and 4 mg/kg/day of LMWH (M.W. 6000).All agents, including saline, were administered intraperitoneally by implantation ofosmotic mini pumps. Systolic blood pressure was measured by the tail-cuff method ontreatment days 1,7, 14, and 28, and histological examination of harvested cardiac tissueand coronary arteries was performed on day 28. Systolic blood pressure was greater inthe L-NAME, LMWH3000 and LMWH6000 groups when compared with the controlgroup. There were no significant differences in activated coagulation time (ACT)when comparing the four groups. Medial smooth muscle cell proliferation and hypertrophyand increases in perivascular and myocardial fibrosis were observed in the L-NAMEgroup compared with the control group. Further, these changes were inhibited by thecoadministration of LMWH3000 or LWMH6000. This study demonstrates that LMWHprevents cardiovascular remodeling induced by L-NAME in rat hearts independent of itsanticoagulant activity. Low molecular weight heparin prevents cardiovascular remodeling
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Determinants of severity in dilated cardiomyopathy: The gap of tricuspid and mitral valve opening
IZUMI Manabu,KIBIRA Satoshi,WATANABE Hiroyuki,TSUYA Hiroyuki
秋田医学 31 201 - 209 2004年12月 [査読有り]
研究論文（学術雑誌）
Objectives: The purpose of this study is to analyze factors that influence the gap of
opening timing between the mitral valve (MV) and the tricuspid valve (TV) in
patients with dilated cardiomyopathy (DCM).
Background: The DCM patients with heart failure often show shorter left ventricular
(LV) isovolumic relaxation time (IRT) and longer right ventricular (RV) IRT, which
may influence the gap of opening timing between TV and MV.
Method: We evaluated consecutive 34 patients with DCM. The time between QRS
initial and TV opening (Q-T time), and that between QRS initial and MV opening (QM
time) were measured by pulsed Doppler recording of each ventricular inflow. The
time interval between MV and TV opening (M-T time) was determined by subtracting
Q-M time from Q-T time. In addition, the other Doppler time intervals including preejectional
period, ejection time, IRT were determined. We analyzed the relation
between Doppler time intervals and factors including NYHA classification and rightsided
cardiac pressure.
Result: There is significant relationship (p <0.001) between M-T time and PCWP
(r=0.65), and NYHA (rs=0.67), respectively. The Ll IRT determined by subtraction
of LV IRT from RV IRT, correlated significantly with M-T time (r=0.83, p<O.OOl),
however, the difference between LV and RV in PEP and ET did not correlated
significantly with M-T time.
Conclusion: The gap of opening timing between TV and MV, determined as M-T time,
correlates strongly with LlIRT and also the severity of congestive heart failure in DCM
patients. -
Cell swelling， heat and chemical agonists use distinet pathways for the activation of the cation channel TRPV4
Vriens J， Watanabe H et. Al
Proc Natl Acad Sci USA 2004 101 ( 1 ) 396 - 401 2004年01月 [査読有り]
研究論文（学術雑誌） 国内共著
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Reduction of ST elevation in repeated coronary occlusion model depends on both altered metabolic response and conduction property.
Takashi Saito, Hiroto Miura, Yutaka Kimura, Hiroyuki Watanabe, Akira Nakagomi, Yoshikazu Tamura, Hitoshi Hasegawa, Satoshi Kibira, Mamoru Miura
International journal of cardiology 92 ( 2-3 ) 219 - 27 2003年12月 [査読有り]
研究論文（学術雑誌）
The aim of this study was to elucidate the mechanisms of altered electrical response to ischemia in repeated coronary occlusion model. To test its dependence on metabolic response, extracellular K+ concentration (eKC), myocardial pH and PCO2 were simultaneously measured with epicardial ECG during three consecutive 4 min of left anterior descending coronary artery (LAD) occlusion separated by 15 min of reperfusion in canine hearts. ECG changes induced by infusion of high K+-buffer (10 mM) into the coronary arterial bed via carotid artery-LAD bypass (referred to as high K+-challenges: HKC) were also tested prior to (the first HKC), and during each reperfusion period (the second to the fourth HKC). ST elevation was significantly reduced in subsequent occlusions (3.14 +/- 0.48 and 2.98 +/- 0.47 mV in the second and third occlusion, both P<0.05, compared to 4.91 +/- 0.78 mV in the first). This was accompanied by significant attenuation of the changes in eKC, tissue pH and PCO2. ST elevation induced by HKC also significantly reduced after repeated occlusion (4.09 +/- 0.79 mV in the fourth HKC vs. 5.64 +/- 0.68 mV in the first, P<0.05) in spite of the identical changes in eKC during HKC. This progressive decrease in ST changes by HKC was rather consistent with augmented conduction delay (86.4 +/- 7.1% increase in activation time in the fourth vs. 54.3 +/- 3.4% in the first, P<0.01). These findings indicate that repeated ischemia induces altered electrical response to subsequent ischemia based on both attenuated metabolic response and altered conduction property.
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Pitavastatin inhibits upregulation of intermediate conductance calcium-activated potassium channels and coronary arteriolar remodeling induced by long-term blockade of nitric oxide synthesis.
Yutaka Terata, Takashi Saito, Yoshimasa Fujiwara, Hitoshi Hasegawa, Hiroto Miura, Hiroyuki Watanabe, Yoshikatsu Chiba, Satoshi Kibira, Mamoru Miura
Pharmacology 68 ( 4 ) 169 - 76 2003年08月 [査読有り]
研究論文（学術雑誌）
UNLABELLED: We have reported that intermediate conductance Ca(2+)-activated K(+) channels (ImK) showed augmented expression in angiotensin II (AII) type 1 receptor-dependent manner in post-ischemic rat heart. ImK has tyrosine phosphorylation sequence in the C-terminus and motifs for NFkappaB and AP1 in the promoter. While statin inhibits AII-mediated vascular remodeling via anti-inflammatory effect independent of cholesterol lowering. To test the possible effect of statin on expression of ImK, Wistar-Kyoto rats received L-nitro-arginine methyl ester (LNAME: 1 mg/ml in drinking water) for 4 weeks in group L. While in L+P group, rats received both LNAME and pitavastatin (PTV: 1 mg/kg/day in drinking water). Temporal profile of ImK mRNA was examined by RT-PCR using specific primers for ImK. RESULTS: Long-term LNAME administration produced significant hypertension and resulted in marked microvascular remodeling characterized by medial thickening and perivascular fibrosis of coronary arterioles (100-200 microm in diameter). RT-PCR revealed significant up-regulation of ImK mRNA with two distinct peaks in L group in the early phase (days 3-7) and the late phase (4 weeks). PTV partially inhibited a rise in systolic blood pressure, but completely abolished the first peak of ImK upregulation (0.76 +/- 0.04 vs. 3.96 +/- 1.43 folds at day 7, p < 0.001). Co-treatments with PTV also significantly inhibited medial thickening and perivascular fibrosis. These findings indicate that statin inhibits microvascular remodeling induced by chronic inhibition of NO synthesis through the action independent of cholesterol lowering.
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The TRPV4 channel: structure-function relationship and promiscuous gating behaviour.
Bernd Nilius, Hiroyuki Watanabe, Joris Vriens
Pflugers Archiv : European journal of physiology 446 ( 3 ) 298 - 303 2003年06月 [査読有り]
研究論文（学術雑誌）
Transient receptor potential (TRP) channels provide an enormous variability of Ca(2+) influx mechanisms triggered by a wide range of stimuli. In this review, we discuss the activation properties of the Ca(2+)- and Mg(2+)-permeable TRP channel of the vanilloid subfamily TRPV4. This channel is activated by various physical and chemical stimuli, such as cell swelling, heat, phorbols and, probably, by endogenous ligands, which are able to induce Ca(2+) entry. Not much is known about the regulation of this channel. We will refer only to a mechanism of Ca(2+)-dependent inhibition of TRPV4. Possible functional roles of this channel will be correlated with its observed expression pattern. Finally, we discuss the structural determinants of TRPV4 channel function.
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Modulation of TRPV4 gating by intra- and extracellular Ca2+.
Hiroyuki Watanabe, Joris Vriens, Annelies Janssens, Robert Wondergem, Guy Droogmans, Bernd Nilius
Cell calcium 33 ( 5-6 ) 489 - 95 2003年05月 [査読有り]
研究論文（学術雑誌）
We have studied the modulation of gating properties of the Ca2+-permeable, cation channel TRPV4 transiently expressed in HEK293 cells. The phorbol ester 4alphaPDD transiently activated a current through TRPV4 in the presence of extracellular Ca2+. Increasing the concentration of extracellular Ca2+ ([Ca2+](e)) reduced the current amplitude and accelerated its decay. This decay was dramatically delayed in the absence of [Ca2+](e). It was also much slower in the presence of [Ca2+](e) in a mutant channel, obtained by a point mutation in the 6th transmembrane domain, F707A. Mutant channels, containing a single mutation in the C-terminus of TRPV4 (E797), were constitutively open. In conclusion, gating of the 4alphaPDD-activated TRPV4 channel depends on both extra- and intracellular Ca2+, and is modulated by mutations of single amino acid residues in the 6th transmembrane domain and the C-terminus of the TRPV4 protein.
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TNF-alpha rapidly antagonizes the beta-adrenergic responses of the chloride current in guinea-pig ventricular myocytes.
Kenji Iino, Hiroyuki Watanabe, Takashi Saito, Satoshi Kibira, Toshihiko Iijima, Mamoru Miura
Circulation journal : official journal of the Japanese Circulation Society 67 ( 4 ) 347 - 53 2003年04月 [査読有り]
研究論文（学術雑誌）
The purpose of this study was to test the hypothesis that tumor necrosis factor-alpha (TNF-alpha) rapidly antagonizes the beta-adrenergic responses of the chloride current and to clarify the intracellular mechanisms responsible for the anti-adrenergic action. The whole-cell patch-clamp technique was used to monitor the anti-adrenergic effects of TNF-alpha on the cAMP-dependent chloride current (I(Cl)) recorded from isolated guinea-pig ventricular myocytes. Ramp pulses (+/-120 mV; dv/dt = +/-0.4 V/s) were applied from the holding potential of -40 mV. TNF-alpha rapidly (<15 min) inhibited the isoproterenol (Iso, 0.1 micromol/L)-induced I(Cl) in a concentration-dependent manner (30-1,000 U/ml, IC (50) = 144 U/ml, n=30). The inhibitory action of TNF-alpha was also observed when I(Cl) had been previously stimulated by 1 micromol/L forskolin (n=5). Prior exposure of myocytes to 5 microg/ml pertussis toxin (PTX) hardly affected the anti-adrenergic action of TNF-alpha (n=4). However, when I(Cl) was induced by both 8-bromo-cAMP (100 micromol/L) and isobutylmethylxanthine (0.1 mmol/L), TNF-alpha (1,000 U/ml) failed to decrease I(Cl) amplitude (n=5). Prior exposure of myocytes to 5 mg/ml pertussis toxin (PTX) hardly affected the anti-adrenergic action of TNF-alpha (n=4). Furthermore, despite of the presence of nitro-L-arginine methyl ester (0.1 mmol/L), a nitric oxide synthase (NOS) inhibitor, TNF-alpha reversed the Iso-induced increase in I(Cl) (n=5). These results suggest that TNF-alpha rapidly antagonizes the beta-adrenergic responses of I(Cl) by reducing cAMP concentration. This anti-adrenergic action is mediated by neither the PTX-sensitive G proteins regulatory pathway nor constitutive NOS activation.
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Anandamide and arachidonic acid use epoxyeicosatrienoic acids to activate TRPV4 channels
Watanabe H et. Al
Nature 424 ( 6947 ) 434 - 438 2003年01月 [査読有り]
研究論文（学術雑誌） 国内共著
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Beneficial effect of dual-chamber pacing for a left mid-ventricular obstruction with apical aneurysm.
Hiroyuki Watanabe, Satoshi Kibira, Takashi Saito, Hiroshi Shimizu, Toyohiko Abe, Ichirota Nakajima, Kenji Iino, Mamoru Miura
Circulation journal : official journal of the Japanese Circulation Society 66 ( 10 ) 981 - 4 2002年10月 [査読有り]
研究論文（学術雑誌）
Sustained ventricular tachycardia (VT) developed in a 63-year-old woman. The 2-dimensional echocardiogram revealed left mid-ventricular obstructive hypertrophy and a discrete apical chamber. A continuous wave Doppler signal across the mid-ventricular narrowing exhibited early systolic ejection flow and diastolic paradoxical jet flow from the apex to the basal chamber, implying a significant systolic and diastolic intraventricular gradient with a high apical pressure. The left ventriculogram confirmed a mid-ventricular obstruction with an apical aneurysm. Invasive assessment of intraventricular pressure showed a peak-to-peak gradient greater than 100 mmHg. Treatment with antiarrhythmic agents could not prevent the VT, but dual-chamber pacing reduced the intraventricular pressure gradient and suppressed the VT completely. Continuous wave Doppler showed that the early systolic ejection flow from the apex had disappeared, that there was isovolumetric relaxation flow toward the apex and that there was attenuation of the diastolic paradoxical jet flow toward the basal chamber. Such findings by continuous wave Doppler can be useful in pacing therapy for evaluating changes in the severity of mid-ventricular obstruction.