A5053683713- Ion channel regulation and function
- Cardiac electrophysiology and arrhythmias
- Ion Channels and Receptors
- Neuroscience and Neuropharmacology Research
- Neurobiology and Insect Physiology Research
- Neuroscience and Neural Engineering
- Nicotinic Acetylcholine Receptors Study
- Biochemical Analysis and Sensing Techniques
- Cardiac Ischemia and Reperfusion
- Erythrocyte Function and Pathophysiology
- Fibromyalgia and Chronic Fatigue Syndrome Research
- Phytochemicals and Antioxidant Activities
- Electrochemical Analysis and Applications
- Blood properties and coagulation
- Postharvest Quality and Shelf Life Management
- Receptor Mechanisms and Signaling
- Nitric Oxide and Endothelin Effects
- Respiratory and Cough-Related Research
- Lipid Membrane Structure and Behavior
- Fuel Cells and Related Materials
- Analytical Chemistry and Sensors
- Thermoregulation and physiological responses
- Bioactive Compounds and Antitumor Agents
- Cholinesterase and Neurodegenerative Diseases
- Urinary Bladder and Prostate Research
Aichi Gakuin University
2014-2024
Hirosaki University
2024
Griffith University
2019-2024
Kyoto Sangyo University
2018
Nagoya City University
1998-2017
Kyoto Pharmaceutical University
2014
Kyoto Prefectural University of Medicine
2014
University of Leeds
2006-2011
Leeds General Infirmary
2006
National Cerebral and Cardiovascular Center
2003
Changes in membrane tension resulting from stretch represent one of the key elements blood flow regulation vascular smooth muscle. However, molecular mechanisms involved remain unclear. In this study, we provide evidence that a vanilloid receptor (TRPV) homologue, TRPV2 is expressed muscle cells, and demonstrate it can be activated by stretch. Cell swelling caused hypotonic solutions nonselective cation channel current (NSCC) elevated intracellular Ca 2+ ([Ca ] i ) freshly isolated cells...
Current therapies for common types of cancer such as renal cell are often ineffective and unspecific, novel pharmacological targets approaches in high demand. Here we show the unexpected possibility rapid selective killing cells through activation calcium-permeable nonselective transient receptor potential canonical (TRPC) calcium channels by sesquiterpene (-)-englerin A. This compound was found to be a highly efficient, fast-acting, potent, selective, direct stimulator TRPC4 TRPC5 channels....
Piezo1 is a mechanosensitive cation channel with widespread physiological importance; however, its role in the heart poorly understood. Cardiac fibroblasts help preserve myocardial integrity and play key regulating repair remodeling following stress or injury. Here we investigated expression function cultured human mouse cardiac fibroblasts. RT-PCR experiments confirmed that mRNA expressed at levels similar to those endothelial cells. The results of Fura-2 intracellular Ca2+ assay validated...
In a screen of potential lipid regulators transient receptor (TRP) channels, we identified sphingosine-1-phosphate (S1P) as an activator TRPC5. We explored the relevance to vascular biology because S1P is key cardiovascular signaling molecule. TRPC5 expressed in smooth muscle cells human vein along with TRPC1, which forms complex Importantly, also activates TRPC5-TRPC1 heteromultimeric channel. Because TRPC channels are linked neuronal growth cone extension, considered related concept for...
TRPC calcium channels are emerging as a ubiquitous feature of vertebrate cells, but understanding them is hampered by limited knowledge the mechanisms activation and identity endogenous regulators. We have revealed that one channels, TRPC5, strongly activated common lysophospholipids including lysophosphatidylcholine (LPC) but, contrast, not arachidonic acid. Although TRPC5 was stimulated agonists at G-protein-coupled receptors, LPC occurred downstream independently G-protein signaling. The...
1. Ionic currents underlying the action potential were recorded from enzymatically isolated smooth muscle cells of guinea-pig ureter. 2. The a single cell was similar to that multicellular preparation. It showed repetitive spikes on plateau which followed first spike. Treatment with 10 mM-tetraethylammonium (TEA) increased amplitude and duration phase abolished spikes. 3. Under voltage clamp mode, at least two (maybe three) kinds outward activated during depolarizing pulses. main current...
Mechanical-loading and unloading can modify osteoblast functioning. Ca2+ signaling is one of the earliest events in osteoblasts to induce a mechanical stimulus, thereby demonstrating importance underlying sensors for sensation. Here, we examined mechano-sensitive channels PIEZO1 TRPV4 were involved process mechano-sensation osteoblastic MC3T3-E1 cells. The analysis mRNA expression revealed high Piezo1 Trpv4 these We also found that agonist, Yoda1, induced response activated cationic currents...
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multisystemic condition associated with post-infectious onset, impaired natural killer (NK) cell cytotoxicity and ion channel function, namely Transient Receptor Potential Melastatin 3 (TRPM3). Long-term effects of acute respiratory coronavirus 2 (SARS-CoV-2) virus has resulted in neurocognitive, immunological, gastrointestinal, cardiovascular manifestations recently recognised as post disease 2019 (COVID-19) condition....
Effects of cyclopiazonic acid (CPA), a specific inhibitor the Ca 2+ ‐ATPase in sarcoplamic reticulum (SR), on membrane ionic currents were examined single smooth muscle cells freshly isolated from ileal longitudinal strips and urinary bladder guinea‐pig. Under whole‐cell clamp, CPA (1–10 μ m ) reduced peak outward current elicited by depolarization concentration‐dependent manner. The concentration required for 50% decrease was ∼ 3 under these conditions. recovered more than 70% after...
The molecular components of the large-conductance Ca(2+)-activated K(+) channels that are functionally expressed in mitochondria (mitoK(Ca)) cardiac myocytes have not been identified. Our experimental results show transcript corresponding to channel beta1-subunit (BK-beta1) is substantially mammalian heart. A yeast two-hybrid assay showed BK-beta1 protein can interact with a mitochondrial protein, cytochrome c oxidase subunit I (Cco1). Results from immunocytochemical experiments also...
The usefulness of bis-(1,3-dibutylbarbituric acid)-trimethine oxonol (DiBAC4(3)), a voltage-sensitive fluorescent dye, for the measurement membrane potentials (MPs) was evaluated in HEK293 cells, where α or plus β1 subunits large conductance Ca2+-activated K+ (BK) channels were expressed (HEKBKα and HEKBKαβ). intensity DiBAC4(3) measured at various under voltage-clamp calibration to estimate absolute MP semi-quantitatively. resting MPs with roughly comparable those recorded microelectrode;...
Contribution of K + channels derived from the expression ERG, KCNQ, and KCNE subtypes, which are responsible for rapidly slowly activating delayed rectifier currents ( I Kr Ks , respectively) in cardiac myocytes, to membrane was examined stomach circular smooth muscle cells (SMCs). The region-qualified multicell RT-PCR showed that ERG1/KCNE2 transcripts were expressed rat fundus antrum SMCs KCNQ1/KCNE1 but not fundus. Western blotting immunocytochemical analyses indicate ERG1 proteins...
Transient Receptor Potential Melastatin 3 (TRPM3) is a widely expressed calcium-permeable non-selective cation channel that stimulated by high concentrations of nifedipine or physiological steroids include pregnenolone sulphate. Here we sought to identify inhibit TRPM3. Channel activity was studied using calcium-measurement and patch-clamp techniques. Progesterone (0.01-10μM) suppressed TRPM3 evoked metabolites 17β-oestradiol were also inhibitory but the effects relatively small....
(-)-Englerin A ((-)-EA) has a rapid and potent cytotoxic effect on several types of cancer cell that is mediated by plasma membrane ion channels containing transient receptor potential canonical 4 (TRPC4) protein. Because these are Ca2+-permeable, it was initially thought the cytotoxicity arose as consequence Ca2+ overload. Here we show this not case (-)-EA heteromer TRPC4 TRPC1 proteins. Both were required for cytotoxicity; however, although necessary (-)-EA-evoked elevation, not. either...
Glucose and hypotonicity induced cell swelling stimulate insulin release from pancreatic β-cells but the mechanisms are poorly understood. Recently, Piezo1 was identified as a mechanically-activated nonselective Ca2+ permeable cationic channel in range of mammalian cells. As could be through stimulation stretch activated channels, we hypothesised role for release. Two rat β-cell lines (INS-1 BRIN-BD11) freshly-isolated mouse islets were studied. Intracellular measurements performed using...
Effects of pimaric acid (PiMA) and eight closely related compounds on large-conductance K<sup>+</sup> (BK) channels were examined using human embryonic kidney (HEK) 293 cells, in which either the α subunit BK channel (HEKBKα) or both β1 (HEKBKαβ1) subunits heterologously expressed. these (10 μM) membrane potential HEKBKαβ1 monitored by use DiBAC<sub>4</sub>(3), a voltage-sensitive dye. PiMA, isopimaric acid, sandaracoisopimaric dihydropimaric dihydroisopimaric dihydroisopimarinol induced...
An attempt was made to obtain electrophysiological evidence for continuous influx of Ca ion through voltage-dependent channel (VDCC) in smooth muscle during long depolarization, example high K solution. Noninactivated current [ICa(ni)] remaining after the accomplishment inactivation by prolonged depolarization approximately 1 min detected three means under whole cell voltage clamp several types cells. The measurement ICa(ni) performed micropuff application Cd2+ or Ca2+ presence absence 5 mM...
1. Two kinds of transient outward currents were observed upon depolarization single smooth muscle cells isolated from guinea‐pig ureter. The major current was through Ca2(+)‐activated K+ channels (IK(Ca) which had a large conductance (130 pS; 126 mM [K+]i/5.9 [K+]o). 2. smaller (ITO) pharmacologically separated other membrane in the presence 1 mM‐Cd2+ and 2 mM‐tetraethylammonium(TEA+) selectively blocked by 3 mM‐4‐aminopyridine. It peaked (approximately 200 pA) within 10 ms ‐80 to +20 mV its...
The transient receptor potential melastatin-3 (TRPM3) channel forms calcium-permeable, non-selective, cationic channels that are stimulated by pregnenolone sulphate (PregS). Here, we aimed to define chemical requirements of this acute steroid action and potentially reveal novel stimulators with physiological relevance.We used TRPM3 over-expressed in HEK 293 cells, intracellular calcium measurement whole-cell patch-clamp recording techniques.The stimulation was confined PregS closely related...