記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.lfs.2023.122208

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1113/jp284283

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.bpj.2022.11.2940

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

Background

Nitric oxide (NO), released from vascular endothelial cells in response to mechanical stimuli, regulates cardiac contractility and are also involved in the prevention of the development of cardiac hypertrophy.

Purpose

To establish an experimental system for live observation of NO release in response to mechanical stimuli on an organ chip.

Methods

Organ chips, which we used for the development of a heart-on-a-chip in the previous study [1], were used.

We seeded 300,000 human umbilical vein endothelial cells on a stretchable elastic membrane coated with Matrigel of a chip channel. Shear stress was applied to the cells by increasing flow rate of a peristaltic pump connected to the chip channel (Figure 1A). Pressure stimulus was applied by hydrostatic pressure. Stretch stimulus was applied by suction to the side ports of a chip using an electric syringe pump (Figure 1B). Cells were stained with 10 μM 4,5-diaminofluorescein diacetate for fluorescent live NO imaging.

Results

Monolayers of the endothelial cells formed intercellular junctions confirmed by CD31 staining (Figure 1C, yellow). Apparent permeability, which was measured by Texas red dye (MW 3000), was maintained at a low level of ∼3x10–6 cm/s until day 30, suggested the formation of robust intercellular junction.

When the endothelial cells were subjected to a pressure stimulus of 60 mmHg for 60 s, NO release was observed that lasted for >2 minutes (Figure 2A). A peak value of 1.46±1.08 (mean ± standard deviation) times the baseline was observed 271 s after the beginning of the pressure stimulus (n=251 cells). When the cells were subjected to a 1% stretch for 60 s, a peak value of 1.29±0.33 times the baseline was observed 105 s after the beginning of the stretch stimulus (Figure 2B). A shear stress of 0.01 dyn/cm2 hardly increased NO release (1.20±0.27 times the baseline, Figure 2C).

Conclusion

The system for live NO imaging in vascular endothelial cells in response to mechanical stimuli was established using organ-on-a-chip. The heart-on-a-chip with endothelial cells will be useful in elucidating the effects of mechanical stimulus such as hypertension on the contractile function and the remodeling of the heart.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

DOI： 10.1093/eurheartj/ehac544.3027

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Cardiomyocytes are contractile cells that regulate heart contraction. Ca2+ flux via Ca2+ channels activates actomyosin interactions, leading to cardiomyocyte contraction, which is modulated by physical factors (e.g., stretch, shear stress, and hydrostatic pressure). We evaluated the mechanism triggering slow contractions using a high-pressure microscope to characterize changes in cell morphology and intracellular Ca2+ concentration ([Ca2+]i) in mouse cardiomyocytes exposed to high hydrostatic pressures. We found that cardiomyocytes contracted slowly without an acute transient increase in [Ca2+]i, while a myosin ATPase inhibitor interrupted pressure-induced slow contractions. Furthermore, transmission electron microscopy showed that, although the sarcomere length was shortened upon the application of 20 MPa, this pressure did not collapse cellular structures such as the sarcolemma and sarcomeres. Our results suggest that pressure-induced slow contractions in cardiomyocytes are driven by the activation of actomyosin interactions without an acute transient increase in [Ca2+]i.

DOI： 10.1016/j.bpj.2022.07.016

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

Abstract

Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity. In this review, we discuss current understanding regarding the mechanisms of cellular gravity sensing in plants and animals. Understanding gravisensing also contributes to life on Earth, e.g., understanding osteoporosis and muscle atrophy. Furthermore, in the current age of Mars exploration, understanding cellular responses to gravity will form the foundation of living in space.

DOI： 10.1038/s41526-020-00130-8

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その他リンク： http://www.nature.com/articles/s41526-020-00130-8

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press (OUP)  

Abstract

Background

The use of animal models in cardiovascular research is associated with two serious, intrinsic problems: inaccuracy in the extrapolation of data obtained from animals such as rodents due to different cardiac physiology and animal ethics.

Purpose

To develop an artificial human heart model for cardiovascular research using organ-on-a-chip technology and human cells

Methods

Organ chips made of silicone (polydimethylsiloxane) that have two microfluidic channels, a top channel and a bottom channel, separated by a 50-μm thick membrane with 7-μm pores hexagonally packed at 40-μm intervals (Figure 1), were used in this study.

We seeded 10,000 human umbilical vein endothelial cells on the membrane surface in the bottom channel to mimic the vasculature. Next, we seeded a mixture of 100,000 human-induced pluripotent stem cells (hiPSCs) and 50,000 human gingival fibroblasts on the membrane surface in the top channel (Figure 1). Human gingival fibroblasts facilitate cardiac differentiation of hiPSCs [1]. We performed the cardiac differentiation of hiPSCs using a previously described protocol [1]. Culture medium was perfused at a constant rate of 60 μl/h to maintain the culture.

Results

We observed spontaneous contraction of hiPSC-derived cardiomyocytes 20–26 days after the start of the differentiation protocol. Simultaneously, we conducted live intracellular calcium imaging using a fluorogenic calcium-sensitive dye, Cal-520 AM (5 μM in the culture medium). hiPSC-derived cardiomyocytes exhibited a periodic, coordinated pattern of calcium influx synchronised with their contraction under fluorescence microscopy (Figure 2A). Moreover, we found that the β-adrenergic agonist noradrenaline elevated the heart rate of hiPSC-derived cardiomyocytes on the organ chips in a dose-dependent manner (Figures 2A, B).

After observing the contraction and intracellular calcium influx of hiPSC-derived cardiomyocytes, we performed immunocytochemistry. Confocal microscopy indicated that the fluorescent signal obtained from anti-cardiac troponin T antibody staining in the top channel exhibited a typical striated pattern with 1.56±0.12-μm interval that reflected sarcomere structure (Figure 2C, yellow). Moreover, the fluorescent signal obtained from anti-CD31 antibody staining in the bottom channel exhibited a typical pattern at the boundary between cells, which is expected at the cell–cell junction of endothelial cells.

Conclusion

We developed a human heart-on-a-chip model that was confirmed by the functional response to noradrenaline and the histological evidence of sarcomere structure and vasculature, with a capability of live imaging. We expect that this model would be useful for examining the physiological function and for the pharmacological analysis of not only the normal heart but also the heart that reflects specific patient's pathophysiology using patient-derived hiPSCs.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science Figure 1Figure 2

DOI： 10.1093/eurheartj/ehab724.3190

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers Media SA  

Gravity affects the function and maintenance of organs, such as bones, muscles, and the heart. Several studies have used DNA microarrays to identify genes with altered expressions in response to gravity. However, it is technically challenging to combine the results from various microarray datasets because of their different data structures. We hypothesized that it is possible to identify common changes in gene expression from the DNA microarray datasets obtained under various conditions and methods. In this study, we grouped homologous genes to perform a meta-analysis of multiple vascular endothelial cell and skeletal muscle datasets. According to the t-distributed stochastic neighbor embedding (t-SNE) analysis, the changes in the gene expression pattern in vascular endothelial cells formed specific clusters. We also identified candidate genes in endothelial cells that responded to gravity. Further, we exposed human umbilical vein endothelial cells (HUVEC) to simulated microgravity (SMG) using a clinostat and measured the expression levels of the candidate genes. Gene expression analysis using qRT-PCR revealed that the expression level of the prostaglandin (PG) transporter gene <italic>SLCO2A1</italic> decreased in response to microgravity, consistent with the meta-analysis of microarray datasets. Furthermore, the direction of gravity affected the expression level of <italic>SLCO2A1</italic>, buttressing the finding that its expression was affected by gravity. These results suggest that a meta-analysis of DNA microarray datasets may help identify new target genes previously overlooked in individual microarray analyses.

DOI： 10.3389/fcell.2021.689662

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.bbrc.2021.03.077

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE: Transient receptor potential vanilloid channel 2 (TRPV2) is a Ca2+ -permeable channel and plays a role in mediating intracellular Ca2+ current via mechanical stimuli. This study was undertaken to examine the expression and role of TRPV2 in adult articular cartilage and the development of osteoarthritis (OA). METHODS: We examined TRPV2 expression in mouse and human articular cartilage. We analyzed the development of OA in Col2a1-CreERt2 ;Trpv2fl/fl mice and Trpv2fl/fl littermates in the resection of the medial meniscus and medial collateral ligament model (n = 5 each), the destabilization of the medial meniscus model (n = 5 each), and the aging mouse model (n = 8-9 each). We examined marker protein expression in these joints, Ca2+ influx by mechanical stimuli, and downstream pathways in vitro. RESULTS: TRPV2 was expressed in mouse and human articular cartilage and ectopic ossification lesions. In all mouse models of OA examined, Col2a1-CreERt2 ;Trpv2fl/fl mice were observed to have enhanced degradation of articular cartilage accompanied by decreased expression of lubricin/Prg4, and marked formation of periarticular ectopic ossification. Mechanical stress-induced Ca2+ influx was decreased by Trpv2 knockout (KO). Prg4 induction by fluid-flow shear stress was diminished in Trpv2-KO mouse chondrocytes, and this was mediated by the Ca2+ /calmodulin-dependent protein kinase kinase-cyclic AMP response element binding protein axis. Hypertrophic differentiation was enhanced in Trpv2-KO mouse chondrocytes. Increased activity of calcineurin and nuclear translocation of nuclear factor in activated T cells 1 induced by fluid-flow shear stress or TRP agonist treatment was reversed by Trpv2 knockout. CONCLUSION: Our findings demonstrate regulation of articular cartilage by TRPV2 through Prg4 induction and suppression of ectopic ossification.

DOI： 10.1002/art.41684

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.mex.2021.101404

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

Lifestyle changes, such as overeating and underexercising, can increase the risk of prediabetes. Diabetes is one of the leading causes of atherosclerosis, and recently it became clear that the pathophysiology of atherosclerosis progresses even before the onset of diabetic symptoms. In addition to changes in platelets and leukocytes in the hyperglycemic state and damage to vascular endothelial cells, extracellular vesicles and microRNAs were found to be involved in the progression of prediabetes atherosclerosis. This review discusses the cellular and molecular mechanisms of these processes, with an intention to enable a comprehensive understanding of the pathophysiology of prediabetes and atherosclerosis.

DOI： 10.3390/ijms22084108

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers Media SA  

Reactive oxygen species (ROS) plays a role in intracellular signal transduction under physiological conditions while also playing an essential role in diseases such as hypertension, ischemic heart disease, and diabetes, as well as in the process of aging. The influence of ROS has some influence on the frequent occurrence of cardiovascular diseases (CVD) in diabetic patients. In this review, we considered the pathophysiological relationship between diabetes and CVD from the perspective of ROS. In addition, considering organ damage due to ROS elevation during ischemia–reperfusion, we discussed heart and lung injuries. Furthermore, we have focused on the transient receptor potential (TRP) channels and L-type calcium channels as molecular targets for ROS in ROS-induced tissue damages and have discussed about the pathophysiological mechanism of the injury.

DOI： 10.3389/fcvm.2021.649785

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI AG  

A thrombus in a coronary artery causes ischemia, which eventually leads to myocardial infarction (MI) if not removed. However, removal generates reactive oxygen species (ROS), which causes ischemia–reperfusion (I/R) injury that damages the tissue and exacerbates the resulting MI. The mechanism of I/R injury is currently extensively understood. However, supplementation of exogenous antioxidants is ineffective against oxidative stress (OS). Enhancing the ability of endogenous antioxidants may be a more effective way to treat OS, and exosomes may play a role as targeted carriers. Exosomes are nanosized vesicles wrapped in biofilms which contain various complex RNAs and proteins. They are important intermediate carriers of intercellular communication and material exchange. In recent years, diagnosis and treatment with exosomes in cardiovascular diseases have gained considerable attention. Herein, we review the new findings of exosomes in the regulation of OS in coronary heart disease, discuss the possibility of exosomes as carriers for the targeted regulation of endogenous ROS generation, and compare the advantages of exosome therapy with those of stem-cell therapy. Finally, we explore several miRNAs found in exosomes against OS.

DOI： 10.3390/ijms22041729

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/ijms21249352

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3389/fcell.2020.00307

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3791/61104

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2020.01.047

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41467-019-13623-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.yexcr.2019.111556

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2019.09.119

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.18926/AMO/56863

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ceca.2019.02.008

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrep.2018.09.003

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/s41598-018-35049-4

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.5040564

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2018.07.116

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/cells7060062

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s12576-016-0519-3

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担当区分：最終著者  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.yjmcc.2017.12.001

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.pbiomolbio.2017.05.015

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.pbiomolbio.2017.06.010

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.pbiomolbio.2017.05.011

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.1093/eurheartj/ehx501.45

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記述言語：英語   出版者・発行元：MDPI AG  

Long-term habitation in space leads to physiological alterations such as bone loss, muscle atrophy, and cardiovascular deconditioning. Two predominant factors-namely space radiation and microgravity-have a crucial impact on oxidative stress in living organisms. Oxidative stress is also involved in the aging process, and plays important roles in the development of cardiovascular diseases including hypertension, left ventricular hypertrophy, and myocardial infarction. Here, we discuss the effects of space radiation, microgravity, and a combination of these two factors on oxidative stress. Future research may facilitate safer living in space by reducing the adverse effects of oxidative stress.

DOI： 10.3390/ijms18071426

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PubMed

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担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：CELL PRESS  

DOI： 10.1016/j.bpj.2016.11.1471

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：wiley  

Long-term exposure to pressure/volume overload of the heart due to hypertension or aortic stenosis induces pathological hypertrophy and remodeling, and eventually causes heart failure. This process accompanies pathological phenomena such as inflammation, apoptosis, and arrhythmia. On the other hand, physical exercise promotes physiological hypertrophy and remodeling of the heart, thereby enhancing cardiac performance. Interestingly, recent research has suggested that enhancement of heart function is a result not only of physiological hypertrophy of pre-existing cardiomyocytes, but also of cardiac stem cell activation and myocyte formation. Furthermore, exercise improves exacerbated cardiac function in heart diseases, including dilated cardiomyopathy (DCM) and myocardial infarction (MI). The suggested mechanisms of action of exercise remedies for these diseases include angiogenesis, cardiac resynchronization, and inhibition of inflammatory cytokines. However, excessive exercise can cause arrhythmogenic remodeling and sudden death. In this chapter, we elaborate the mechanisms of hypertrophy and remodeling under physiological and pathological conditions and discuss future directions for coping with pathological hypertrophy and remodeling.

DOI： 10.1002/9781118966174.ch11

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/cvr/cvw113

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/jdi.12452

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Springer Japan  

This article describes how physical forces contribute to development, physiology, and pathology of vascular cells, focusing on endothelial cells and vascular smooth muscle cells. Based on these basic understandings of the mechanobiology, we discuss mechanomedicine, an application of the mechanobiology to medicine. Basic knowledge about cellular responses, such as cellular signal transduction pathway, gene expression, and cytoskeletal remodeling, to mechanical stimuli is important for understanding the pathology of vascular diseases including atherosclerosis. Introducing the knowledge of the vascular mechanobiology will not only contribute to the development of regenerative medicine using pluripotent stem cells but also provide a way to prevent diseases caused by thromboembolisms, such as myocardial and cerebral infarctions.

DOI： 10.1007/978-4-431-54801-0_15

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0141989

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0121703

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/s150407898

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1165/rcmb.2014-0008OC

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2014.09.063

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japanese Society for Medical and Biological Engineering  

Na⁺/Ca²⁺ exchanger (NCX1) is essential Ca²⁺ regulator of myocyte Ca²⁺ homeostasis and specially localized at transverse tubules (T-tubules) membrane. T-tubules are invaginations of the sarcolemma and critical for myocyte contraction, especially as the main site of excitation-contraction coupling. Therefore, T-tubule disorganization is linked to decreased contractility in heart failure, but the molecular mechanism is not clear. We analyzed the alteration of T-tubule structure and Ca2+ handling during the progression of heart failure after transverse aortic constriction (TAC)-surgery, using cardiac-specific and inducible NCX1 transgenic mice. In progression of cardiac dysfunction, sarcoplasmic reticulum Ca²⁺ ATPase and NCX1 activity were down-regulated before T-tubule disorganization. The inducing NCX1 overexpression after TAC-surgery prevented T-tubule disorganization and contractile dysfunction under prolonged pressure-overload, with improvement of myocyte Ca²⁺ handling. These results suggest that local Ca²⁺ control beneath the T-tubule membrane is crucial for the maintenance of myocyte structure and function, in which NCX1 has a pivotal role.

DOI： 10.11239/jsmbe.52.O-212

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Soc. of Med. Electronics and Biol. Engineering  

Low-cost paper-based diagnostic device for human sperm motility has developed to know sperm motility without consulting fertility clinics. We compared the signal pattern of the paper-based sperm motility assay using 4-channel pattern (cross) and 2-channel pattern (line) papers, and investigated difference in signal patterns using some tetrazorium salts for the assay. Using these two paper patterns, we can examine whether human sperm motility in semen is more than 50% or 0%. XTT and WST-8 reagents treated paper-based device can be used. We concluded that MTT treated line pattern paper is suitable for the purpose to reduce the cost of the device.

DOI： 10.11239/jsmbe.52.O-551

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Soc. of Med. Electronics and Biol. Engineering  

Myocardium contracts against ventricular wall stretch that comes along with ventricular filling. Mitochondria generate required ATP for myocardial contraction. It is well known that mitochondrial ATP production process is one of the sources of reactive oxygen species (ROS). ROS are known as toxic molecules, but also important physiological regulators of intracellular signaling pathways. In the present study, we investigate the relation between myocardial stretch and mitochondrial ROS production, and discuss the role of mitochondria on myocardial response to stretch. Isolated mouse ventricular myocytes were exposed to 10% axial stretch using carbon fiber technique. ROS production was studied using DCF-loaded cells. Axial stretch significantly increased ROS production. Applying 5 μM mitochondrial metabolic uncoupler FCCP blunted the response, indicating mitochondrial ROS production is stretch-sensitive. The present results suggest that stretch enhances electron transport chain to prepare for the more ATP production for the more preloaded, namely, the more energy-consuming contraction.

DOI： 10.11239/jsmbe.52.SY-44

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.pbiomolbio.2014.06.005

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0102796

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0102778

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10404-014-1378-y

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/ncomms4932

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記述言語：日本語   出版者・発行元：日本骨形態計測学会  

細胞内カルシウム(Ca2+)は多様な細胞機能を仲介する重要な情報伝達物質であり、Ca2+オシレーションと呼ばれる周期的なCa2+濃度の上昇様式は、骨代謝調節を含む広範な生理機構に関与すると考えられている。しかし、3次元的な骨芽細胞-骨細胞ネットワークから成り立つ骨組織中でのCa2+オシレーションの動態は、周囲の骨基質が障壁となるためこれまで不明であった。近年我々は、骨組織をまるごと生きた状態のままCa2+イメージングする事に成功し、骨芽細胞と骨細胞の自律性細胞内Ca2+オシレーションの存在と、それらの現象に対するメカニカルストレスの影響およびギャップ結合の関与について報告した。本論文では、蛍光ライブイメージングを用いた骨組織中のCa2+オシレーションについて最新の研究成果を交えて解説する。(著者抄録)

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DOI： 10.1016/j.job.2014.03.002

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その他リンク： http://orcid.org/0000-0002-4419-9643

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/prp2.68

PubMed

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記述言語：英語   出版者・発行元：American Institute of Mathematical Sciences  

Coarse-grained molecular dynamics (CGMD) simulations are increasingly being used to analyze the behaviors of biological systems. When appropriately used, CGMD can simulate the behaviors of molecular systems several hundred times faster than elaborate all-atom molecular dynamics simulations with similar accuracy. CGMD parameters for lipids, proteins, nucleic acids, and some artificial substances such as carbon nanotubes have been suggested. Here we briefly discuss a method for CGMD system configuration and the types of analysis and perturbations that can be performed with CGMD simulations. We also describe specific examples to show how CGMD simulations have been applied to various situations, and then describe experimental results that were used to validate the simulation results. CGMD simulations are applicable to resolving problems for various biological systems.

DOI： 10.3934/biophy.2014.1.1

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejphar.2013.05.030

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1093/hmg/ddt157

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0070587

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/cm.21097

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PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bone.2012.12.002

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.rbmo.2012.11.014

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1089/ten.tea.2012.0099

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3390/s130202484

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1111/jcmm.12027

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.pbiomolbio.2012.08.001

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1002/cm.21032

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bone.2012.01.021

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.biomaterials.2011.10.049

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.rbmo.2011.09.005

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Using an air-actuating device, we investigated the cellular response to mechanical stimuli (MS) in mouse blastocysts. Both MS and intracellular calcium concentration ([Ca 2+] i) were quantified based on time-resolved confocal microscopy images in the polydimethylsiloxane (PDMS) microfluidic channels by deforming a 0.1-mm membrane. [Ca 2+] i was measured in a stained mouse embryo with Fluo-4 AM using confocal fluorescence microscopy. We captured a z-series stack of sections encompassing the entire embryo. When translocation velocities of the embryo and shear stress were 40 μm/s and 0.01 dyne/cm 2, respectively, a 10% increase in the sum of fluorescent intensities (FI) was observed. When blastocysts were compressed, FI also increased in response to the applied MS. Compressive force estimated from the shape of the blastocysts was approximately 0.5-2.0 μN according to a force deformation curve for the mouse embryo. The average FI and sum of FIs increased by a factor of 1.1-1.2 times compared with those observed before MS. The increase in the sum of FI indicated that enhancement of [Ca 2+] i would be induced by these MS. © 2011 IEEE.

DOI： 10.1109/MHS.2011.6102167

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1253/circj.CJ-11-0486

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1371/journal.pone.0026384

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00776-011-0128-1

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.joca.2010.11.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejeiss.131.1535

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2010.10.043

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1262/jrd.10-041H

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.theriogenology.2010.04.011

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.fertnstert.2009.11.003

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1165/rcmb.2009-0073OC

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1113/expphysiol.2009.051896

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.rbmo.2009.12.002

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.snb.2009.09.045

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Throughput in the cell response analysis is expected to progress in medicine and biology. In this paper, we construct a method for the measurement of cell activity that is measured by the pH fluctuation of the solution around the cell. To improve throughput of the measurements, first we constructed an automatic pH measurement system using ion-sensitive field-effect transistor (ISFET), and the system composed of 96-well microplate, pump, XYZ stage, and PC. The basic data of the cell activity was taken from human embryonic kidney 293 (HEK 293) cells by the use of flow-through type measuring chamber. ©2010 IEEE.

DOI： 10.1109/MHS.2010.5669583

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.20965/jrm.2010.p0197

CiNii Article

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Mammalian embryos experience not only hormonal but also mechanical stimuli, such as shear stress, compression, and friction force, in the fallopian tube before nidation. We aim to develop a novel and simple system to apply mechanical stimuli (MS) similar to those generated inside the oviduct to cultured mammalian embryos. Possible MS include shear stress (SS) caused by fluid dynamics and compression of embryos due to interactions with the wall of the oviduct. A new culture system was developed to increase SS and to apply MS during in vitro embryo cultures. We developed an air actuating system with microfluidic channels to apply MS by deforming a 0.1-mm-thick poly(dimethylsiloxiane) membrane and evaluated MS applied to ICR mouse embryos inside the microfluidic channel. Using this air actuating system, we applied compression to mouse embryos inside the medium channel and estimated SS on the basis of the velocity of the embryos' motion. By changing the syringe velocity, we applied different types of MS to the em bryos. These results suggested that multiple MS such as SS and compression can be applied at the same time. MS applied using this system was similar to those generated in the physiological environment of the oviduct. ©2010 IEEE.

DOI： 10.1109/MHS.2010.5669581

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TNB.2009.2035253

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2009.09.020

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.atherosclerosis.2009.02.023

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jbiomech.2009.06.016

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2009.05.105

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1074/jbc.M109.020206

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s10544-008-9207-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1055/s-0028-1087170

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1039/b910826b

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3233/CH-2009-1164

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE SA  

We have previously reported that a flow-through type pH/CO2 sensor system using two ion sensitive field effect transistors (ISFETs) could be utilized to evaluate the production rate of total carbonate (secreted CO2 + secreted bicarbonate ion) and free lactic acid (secreted lactic acid -secreted bicarbonate ion). To validate the usefulness of this system, we applied it to the quantitative analysis of metabolic switching by the change Of glucose concentrations in cultured bovine arterial endothelium cell, human umbilical vein endothelium cell and rat cardiac muscle cell. In all of these cell species, a decrease of glucose concentration increased total carbonate that represents the cellular respiration activity and decreased free lactic acid that represents glycolysis activity. We firstly analyzed a switching of metabolic pathways from glycolysis to respiration with a decrease of glucose quantitatively. This ISFET system can be applicable to many biological investigations by analyzing metabolic activity and give dynamic cellular information. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.snb.2008.05.021

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/bjp.2008.140

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1165/rcmb.2007-0259OC

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/japplphysiol.00870.2007

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jbiotee.2007.07.955

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.jbiotec.2007.09.017

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpheart.00548.2006

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記述言語：英語   出版者・発行元：The Institute of Electrical Engineers of Japan  

Automatic pH measurement system was developed by using a flow-through type differential pH-FET sensor. The system was operated by repeating 60 sec cycle consisting of 36 sec of washing period, 4 sec of moving period, and 20 sec of measuring period. In washing period, the differential pH-FET sensor was washed with baseline solution. In measuring period, about 50 μl of sample solution was withdrawn to the space around a measurement pH-FET, and the change of differential source potential was measured. Absolute values of error for nine sample solutions with weak buffering ability were less than 0.146 pH, and were 0.071 pH in average. From this experiment, it was suggested that high-speed and automated pH measurement will be possible by using pH-FET sensors even for sample solutions of weak buffer ability.

DOI： 10.1541/ieejsmas.127.367

CiNii Article

CiNii Books

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00298152597?from=CiNii

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1159/000103375

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.ejphar.2006.08.067

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajplung.00299.2005

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.lfs.2005.12.051

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1080/09687860500370703

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/sj.bjp.0706182

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1152/ajpcell.00314.2004

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/nmat1365

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.lfs.2004.10.050

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

Here we present long-term patterning and response studies of neuroblasts on arrays of extracellular matrix (ECM) protein lines fabricated by cracking a polymer-supported thin film and selectively depositing proteins inside the cracks. Neuroblasts cultured for five days on the protein matrix switched between spreading and retraction upon changing the protein line width. This technique provides a novel tool to pursue further understanding of the basic mechanisms of neuroblast pathfinding on adhesion and morphology. Biomedical device design will also benefit from materials engineered with the reconfigurable protein patterns.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.cardiores.2003.10.016

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1007/s00232-003-0637-8

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S0006-291X(03)01362-7

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S1074-5521(03)00019-X

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/S0168-8278(02)00171-X

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1161/hq0202.104123

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1096/fj.01-0354fje

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY  

1 Human umbilical vein endothelial cells cultured on a transparent silicone chamber were subjected to a short stretch pulse (ca. 1 s, 5-25% stretch) of their substrate and following increases in intracellular Ca2+ concentration ([Ca2+](i)) were measured by fluorescence intensity ratiometry using fura-2.
2 In response to mechanical stretch, the cells in HEPES buffered saline exhibited a Ca2+ transient in a dose dependent way. The response was completely dependent on external Ca2+ and inhibited by gadolinium (Gd3+), suggesting that it was mediated by the activation of a stretch activated cation channel (SACatC).
3 Interestingly, the stretch induced Ca2+ transient was significantly augmented in the presence of basic polypeptide, protamine. This augmented Ca2+ response was inhibited neither by Gd3+ nor by the deprivation of external Ca2+, indicating that the SACatC is not responsible for this phenomenon.
4 In contrast, this augmentation was inhibited by depletion of intracellular Ca2+ stores with thapsigargin or by the pretreatment with phospholipase inhibitors such as U73122 and manoalide.
5 These results suggest the presence of a metabotropic mechanoreceptor distinct from the SACatC in vascular endothelium. This augmented [Ca2+](i) increase may contribute to the vasodilating response induced by protamine during heparin neutralization in cardiac surgery.

DOI： 10.1038/sj.bjp.0704386

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

We investigated the role of tyrosine phosphorylation of FAK in the stretch-induced MAPKs (extracellular signal-regulated kinase (ERK), p38MAPK) activation in mutant FAK-transfected fibroblasts. In response to uniaxial cyclic stretch (1 Hz, 120% in length), the levels of tyrosine phosphorylation of the Tyr-397 and Tyr-925 of FAK in control cells increased and peaked at 5 min (2.75 +/- 0.51, n = 3), and 20 min (2.98 +/- 0.58, n = 3), respectively, and the activities of MAPKs increased and peaked at approximately 10 min. On the other hand, in the mutant FAK-transfected cells, the stretch-induced MAPKs activation was significantly inhibited. The stretch-induced activation of MAPKs was also significantly abolished by either treatment with Gd3+ or extracellular Ca2+ removal which may inhibit intracellular Ca2+ increase caused by the activation of cation selective (Ca2+-permeable) stretch activated (SACatC) channels. These results suggest that the stretch-induced tyrosine-phosphorylation of FAK via SACatC activation is critical for the stretch-induced MAPKs activation. (C) 2001 Academic Press.

DOI： 10.1006/bbrc.2001.5775

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Superoxide production in response to cyclic stretch (1 Hz, 20 % in length) was investigated in human umbilical vein endothelial cells (HUVECs). The basal production of superoxide without stretch increased gradually, while the production of superoxide with stretch increased significantly as compared to that without stretch and it became significant 80 min after the onset of cyclic stretch (P&lt;0.05, n=8-14). The superoxide production increased in a stretch-dependent manner and became significant when stretch was more than 10 % (p&lt;0.05, n= 11-16). To investigate the involvement of SA channel, we added Gd3+ or EGTA in the reaction solution and examined the stretch-induced superoxide production. In cells stretched in the presence of 20 muM Gd3+, the stretch-induced superoxide production was significantly inhibited (at 120 min, p&lt;0.05, n=8-18). The cyclic stretch-induced superoxide production was also significantly inhibited by the removal of extracellular Ca2+ with 5 mM EGTA (at 120 min, p&lt;0.05, n = 8-18). Neither the application of Gd3+ nor the removal of extracellular Ca2+ significantly changed the basal production of superoxide. These data suggest that the stretch-induced superoxide production increases in time- and stretch-dependent manner and that the stretch-induced superoxide production in HUVECs is regulated by Ca2+ influx through SA channels. (C) 2001 Elsevier Science Inc. All rights reserved.

DOI： 10.1016/S0024-3205(01)01256-5

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATL ACAD SCIENCES  

Alternative models of cell mechanics depict the living cell as a simple mechanical continuum, porous filament gel, tensed cortical membrane, or tensegrity network that maintains a stabilizing prestress through incorporation of discrete structural elements that bear compression. Real-time microscopic analysis of cells containing GFP-labeled microtubules and associated mitochondria revealed that living cells behave like discrete structures composed of an interconnected network of actin microfilaments and microtubules when mechanical stresses are applied to cell surface integrin receptors, Quantitation of cell tractional forces and cellular prestress by using traction force microscopy confirmed that microtubules bear compression and are responsible for a significant portion of the cytoskeletal prestress that determines cell shape stability under conditions in which myosin light chain phosphorylation and intracellular calcium remained unchanged. Quantitative measurements of both static and dynamic mechanical behaviors in cells also were consistent with specific a priori predictions of the tensegrity model. These findings suggest that tensegrity represents a unified model of cell mechanics that may help to explain how mechanical behaviors emerge through collective interactions among different cytoskeletal filaments and extracellular adhesions in living cells.

DOI： 10.1073/pnas.141199598

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1038/35082637

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

When exposed to a uni-axial cyclic stretch, cultured human umbilical vein endothelial cells (HUVECs) align and elongate perpendicular to the stretch axis. Previous studies showed that forskolin inhibited stretch-induced orientation of endothelial cells, suggesting that adenosine3:5-cyclic monophosphate (cAMP) plays an important role in the shape change. However, we have recently shown that stretch-induced shape changes in cultured HUVECs are due to increased [Ca2+],. In the present study, we examined the possible role of cAMP in stretch-induced shape changes in cultured HUVECs, Application of uni-axial cyclic stretch induced a gradual rise in cAMP reaching a peak level at 60 min after the onset of stretch. The adenylate cyclase activator, forskolin, increased the basal level of cAMP but inhibited the rise in [Ca2+](i) resulting in no cell shape changes. In contrast, N 6,2-dibutyryladenosine3:5-cyclic monophosphate (dbcAMP) enhanced the stretch-induced increase in cAMP and [Ca2+] and resulted in cell shape changes. On the other hand, 2'5'-dideoxyadenosine (DDA), an adenylate cyclase inhibitor, inhibited stretch-induced increases in cAMP and [Ca2+]i resulting in no cell shape changes. In summary, our data showed that cell shape changes were consistently dependent on [Ca2+](i) rather than cAMP levels. We conclude that the primary second messenger in the stretch-induced shape changes in HUVECs is intracellular Ca2+ rather than cAMP. (C) 2000 Elsevier Science Inc. All rights reserved.

DOI： 10.1016/S0024-3205(00)00844-4

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS LTD  

The pathogenesis of pericyte loss, an initial deficit in the early stage of diabetic retinopathy, remains unclear. Polyol pathway hyperactivity has been implicated in the pathogenesis of diabetic retinopathy, and recent studies have suggested that apoptosis may be involved in pericyte loss. The present study was conducted to investigate whether high glucose induces apoptosis in cultured bovine retinal pericytes. The effect of an aldose reductase inhibitor. SNK-860, was also examined. After a 5 day incubation with various concentrations of glucose (5.5-40 mM) in the presence or absence of SNK-860, the cell viability and the percentages of dead cells were measured. and staining with the TUNEL method and Hoechst 33342, and DNA electrophoresis were performed. High glucose reduced the viability and increased the percentages of dead cells. TUNEL-positive cells were observed in pericytes under high glucose, but not in those under 5.5 mM glucose. In the staining of nuclei with Hoechst 33342, the percentage of apoptotic cells in total cells counted under high glucose was higher than that under 5.5 mM glucose. DNA electrophoresis of pericytes cultured with high glucose demonstrated a 'ladder pattern'. Hyperosmolarity also induced apoptosis in pericytes, but less than that by high glucose. SNK-860 inhibited the glucose-induced apoptosis in pericytes. These observations suggest that the pericyte loss in diabetic retinopathy involves an apoptotic process, and that the polyol pathway hyperactivity plays an important role in inducing apoptosis in pericytes by high glucose. (C) 2000 Academic Press.

DOI： 10.1006/exer.2000.0882

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1126/science.288.5470.1347

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER ASSOC ADVANCEMENT SCIENCE  

Calcium-permeable, stretch-activated nonselective cation (SA Cat) channels mediate cellular responses to mechanical stimuli. However, genes encoding such channels have not been identified in eukaryotes. The yeast MID1 gene product (Mid1) is required for calcium influx in the yeast Saccharomyces cerevisiae. Functional expression of Midi in Chinese hamster ovary cells conferred sensitivity to mechanical stress that resulted in increases in both calcium conductance and the concentration of cytosolic free calcium. These increases were dependent on the presence of extracellular calcium and were reduced by gadolinium, a blocker of SA Cat channels. Single-channel analyses with cell-attached patches revealed that Midi acts as a calcium-permeable, cation-selective stretch-activated channel with a conductance of 32 picosiemens at 150 millimolar cesium chloride in the pipette. Thus, Midi appears to be a eukaryotic, SA Cat channel.

DOI： 10.1126/science.285.5429.882

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC  

To examine the role of platelet-derived growth factor (PDGF) and the polyol pathway in the growth activity of smooth muscle cells (SMCs), [H-3]-thymidine incorporation, [I-125]-PDGF-BB binding and expression of PDGF-beta receptor protein were measured in rat aortic SMCs cultured with 5.5 or 20 mM glucose with or without anti-PDGF antibody or an aldose reductase inhibitor, epalrestat. SMCs cultured with 20 mM glucose demonstrated an accelerated thymidine incorporation compared with SMCs cultured with 5.5 mM glucose, which was prevented by anti-PDGF antibody. This acceleration of growth activity by 20 mM: glucose was accompanied by an increase in PDGF-BB binding, which was due to the increased number of PDGF-beta receptors and the overexpression of PDGF-beta receptor protein. Epalrestat prevented all these abnormalities. These observations suggest that polyol pathway hyperactivity plays an important role in the proliferation of SMCs which may be mediated through the accelerated expression of PDGF-beta receptor protein. (C) 1999 Academic Press.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

With the use of the patch-clamp technique, five kinds of stretch-activated (SA) ion channels were identified on the basis of their single-channel conductances and ion selectivities in cultured chick ventricular myocytes. Because a high-conductance K+-selective channel predominated among these channels, we concentrated on characterizing its properties mostly using excised inside-out patches. With 145 mM KCl solution in the pipette and the bath, the channel had a conductance of 199.8 +/- 8.2 pS (n = 22). The ion selectivities among K+, Na+, Ca2+, and Cl- as estimated from their permeability ratios were P-Na/P-K = 0.03, P-Ca/P-K = 0.025, and P-Cl/P-K = 0.026. The probability of the channel being open (P-0) increased with the Ca2+ concentration in the bath ([Ca2+](b); dissociation constant Kd = 0.51 mu M at +30 mV) and membrane potential (voltage at half-maximal P-o, = 39.4 mV at 0.35 FIM [Ca2+](b)). The channel was blocked by gadolinium, tetraethylammonium, and charybdotoxin from the extracellular surface and, consequently, was identified as a Ca2+-activated K+ (K-Ca) channel type. The channel was also reversibly activated by ATP applied to the intracellular surface (K-d = 0.74 mM at 0.10 mu M [Ca2+](b) at + 30 mV). From these data taken together, we concluded that the channel is a new type of K-Ca channel that could be designated as an "SA K-Ca,K-ATP channel. "To our knowledge, this is the first report of K-Ca channel in heart cells.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：COMPANY OF BIOLOGISTS LTD  

When subjected to uni-axial cyclic stretch (120% in length, 1 Hz), fibroblasts (3Y1) aligned perpendicular to the stretch axis in a couple of hours. Concomitantly with this orienting response, protein tyrosine phosphorylation of cellular proteins (molecular masses of approximately 70 kDa and 120-130 kDa) increased and peaked at 30 minutes, Immuno-precipitation experiments revealed that paxillin, pp125(FAK), and pp130(CAS) were included in the 70 kDa, and 120-130 kDa bands, respectively. Treatment of the cells with herbimycin A, a tyrosine kinase inhibitor, suppressed the stretch induced tyrosine phosphorylation and the orienting response suggesting that certain tyrosine kinases are activated by stretch. We focused on pp60(src), the most abundant tyrosine kinase in fibroblasts. The kinase activity of pp60(src) increased and peaked at 20 minutes after the onset of cyclic stretch. Treatment of the cells with an antisense S-oligodeoxynucleotide (S-ODN) against pp60(src), but not the sense S-ODN, inhibited the stretch induced tyrosine phosphorylation and the orienting response. To further confirm the involvement of pp60(src), we performed the same sets of experiments using c-src-transformed 3Y1 (c-src-3Y1) fibroblasts. Cyclic stretch induced a similar orienting response in c-src-3Y1 to that in wild-type 3Y1, but with a significantly faster rate. The time course of the stretch-induced tyrosine phosphorylation was also much faster in c-src-3Y1. than in 3Y1 fibroblasts, These results strongly suggest that cyclic stretch induces the activation of pp60(src) and that pp60(src) is indispensable for the tyrosine phosphorylation of pp130(CAS), pp125(FAK) and paxillin followed by the orienting response in 3Y1 fibroblasts.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC  

To deliver nonnuclear proteins into the nucleus, we have examined the locations and number of nuclear localizing signals by use of simian virus 40 large T-antigen (SV40Ta) and yeast enhanced green fluorescent protein (yEGFP) in Saccharomyces cerevisiae as a model system. When only one SV40Ta was added to either the N- or C-terminus of yEGFP, the fluorescence of yEGFP was detected in both the nucleus and the cytoplasm. When two SV40Ta signals were added, one to the N-terminus and one to the C-terminus of yEGFP (SV40Ta-yEGFP-SV40Ta), the fluorescence of yEGFP was localized in only the nucleus. When the presequence of cytochrome oxidase subunit IV (pCOXIV) was inserted between the SV40Ta and the N-terminus of yEGFP (SV40Ta-pCOXIV-yEGFP-SV40Ta) in this construct, the fluorescence was located in both the nucleus and the cytoplasm, suggesting that the increased distance between the two SV40Ta signals decreased the efficiency of transport into the nucleus. When an additional SV40Ta signal was inserted between pCOXIV and yEGFP (SV40Ta-pCOXIV-SV49Ta-yEGFP), the fluorescence was localized only in the nucleus, indicating that two SV40Ta signals spaced by pCOXIV of 28 amino acid residues forming an alpha-helix are potent in transporting yEGFP into the nucleus. These results indicate that two SV40Ta signals spaced appropriately are essential for the efficient transport of the nonnuclear protein into the nucleus. (C) 1999 Academic Press.

DOI： 10.1006/bbrc.1999.0269

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

Prostacyclin (PGI(2)), a metabolite of arachidonic acid, has the vasoprotective effects of vasodilation, anti-platelet aggregation, and inhibition of smooth muscle cell proliferation. We hypothesized that an overexpression of endogenous PGI(2) may accelerate the recovery from endothelial damage and inhibit neointimal formation in the injured artery. To test this hypothesis, we investigated in vivo transfer of the PGI(2) synthase (PCS) gene into balloon-injured rat carotid arteries by a nonviral lipotransfection method. Seven days after transfection, a significant regeneration of endothelium was observed in the arteries transfected with a plasmid carrying the rat PCS gene (pCMV-PCS), but little regeneration was seen in those with the control plasmid carrying the lacZ gene (pCMV-lacZ) (percent luminal circumference lined by newly regenerated endothelium: 87.1+/-6.9% in pCMV-PCS-transfected vessels and 6.9+/-0.2% in pCMV-lacZ vessels, P&lt;0.001). BrdU staining of arterial segments demonstrated a significantly lower incorporation in pCMV-PCS-transfected vessels (7.5+/-0.3% positive nuclei in vessel cells) than in pCMV-lacZ (50.7+/-9.6%, P&lt;0.01). Moreover, 2 weeks after transfection, the PCS gene transfer resulted in a significant inhibition of neointimal formation (88% reduction in ratio of intima/media areas), whereas medial area was similar among the groups. Arterial segments transfected with pCMV-PCS produced significantly higher levels of 6-keto-PGF(1 alpha), the main metabolite of PGI(2), compared with the segments transfected with pCMV-lacZ (10.2+/-0.55 and 2.1+/-0.32 ng/mg tissue for pCMV-PCS and pCMV-placZ, P&lt;0.001). In conclusion, this study demonstrated that an in vivo PCS gene transfer increased the production of PGI(2) and markedly inhibited neointimal formation with accelerated reendothelialization in rat carotid arteries after balloon injury.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

Mechanical stress has been implicated as one of the growth regulators in the heart. We investigated the effect of cyclic stretch stimulation on morphology and orientation of cultured cardiocytes. Embryonic rat (17 days postcoital) cardiomyocytes cultured on silicone dishes were cyclically stretched to 120% in length at a frequency of 30 cycles/min. After 12 h, in the initial stage of cultivation, cardiocytes and intracellular myofibrils oriented parallel to the stretch direction. When the stretch stimulus was prolonged to 24-48 h, myofibrils that oriented perpendicular to the stretch direction emerged. Furthermore. when the cells were stretched only in the later stage (after 24 h of cultivation). both cells and myofibrils tended to orient perpendicular to the stretch direction. Next we examined the effects of chemical compounds on these phase related changes in myofibril orientation None of the drugs tested (H-7, HA-1004, staurosporine, herbimycin A, genistein, GdCl3, and EGTA) blocked the parallel orientation of myofibrils induced by the initial-stage stretch. By contrast, H-7, staurosporine, herbimycin A, and genistein did inhibit almost completely the perpendicular orientation of the myofibrils induced by the late-stage stretch, but HA-1004, GdCl3, or EGTA did not, Immunoblotting study using anti-phsophotyrosine antibody indicated that tyrosine phosphorylation of a protein of about 125 kDa was enhanced in a time-dependent manner by the late-stage stretch, but not by the initial-stage stretch. In conclusion: the alignment change induced by cyclic stretch depends on the stage of cultivation: with stretch in the initial stage (within 12 h), cells and myofibrils orient parallel to the stretch; with stretch in the later stage (after 24 h), they orient perpendicular to the stretch. The effect of stretch in the later stage is likely mediated by protein kinase C and tyrosine kinase pathways. (C) 1999 Academic Press.

DOI： 10.1006/jmcc.1998.0865

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Aims/hypothesis. Although increased polyol pathway activity has been implicated in the pathogenesis of diabetic microangiopathy, the relation with diabetic macroangiopathy remains unclear. Galactose feeding is known to stimulate the polyol pathway and to develop abnormalites similar to those in diabetic microangiopathy. Our study was conducted to investigate whether an activation of polyol pathway by long-term treatment with galactose produced morphological changes in coronary arteries of dogs and the effect of an aldose reductase inhibitor, epalrestat, was also studied. Methods. Dogs received either normal chow or chow containing 30% galactose with or without epalrestat given orally (20 or 50 mg · kg-1). After 44 months, morphometric analyses of coronary arteries were carried out and the galactitol contents in aortas were measured. Results. The ratio of areas of the intimal layer to those of the medial layer, an indicator of intimal thickening, was statistically significantly increased in galactose-fed dogs compared with control dogs. Galactose-fed dogs had a remarkable accumulation of galactitol in their aortas. These morphological and biochemical deficits were reduced by treatment with epalrestat. Conclusion/interpretation. This report morphologically shows diabetes-like macrovascular abnormalities in galactosaemic animals, suggesting that polvol pathway hyperactivity is closely related to the development of diabetic macroangiopathy, which could be prevented by aldose reductase inhibition.

DOI： 10.1007/s001250051310

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY  

The kinase activity of c-src increased and peaked at 15 min after an application of uni-axial cyclic stretch in HUVECs followed by a translocation of c-src to Triton-insoluble fraction. Suppression of c-src by an antisense S-oligodeoxynucleotide inhibited the stretch-induced tyrosine phosphorylation and morphological changes. The stretch-induced increase in c-src activity was inhibited by FK506, a specific inhibitor for calcineurin, by Gd3+, a blocker for stretch activated channels, and by the extracellular Ca2+ depletion suggesting the involvement of SA channels. These results strongly suggest c-src plays an important role in the downstream of SA channel activation followed by the morphological changes. (C) 1998 Federation of European Biochemical Societies.

DOI： 10.1016/S0014-5793(98)01528-2

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS AUST  

When cybrids with a point mutation, which locates in the tRNA(Leu(UUR)) gene of mtDNA and causes a mitochondrial encephalomyopathy (MELAS syndrome), were exposed to a high concentration of oxygen (95%), the peroxide production markedly increased by 6 h of oxygen exposure, whereas the peroxide production was similar among the cybrids under a normal concentration of oxygen. The peroxide production by oxygen exposure was enhanced particularly in cybrids with high proportions of the mutant mtDNA and low respiratory capacities. The appearance of apoptotic cells by oxygen exposure was high in cybrids with the impaired respiratory function due to the mutation. An antioxidant NAC successfully suppressed both the peroxide production and apoptosis. These results imply that the peroxide production plays an important role in inducing apoptosis in :ells carrying; the mtDNA mutation causing encephalomyopathy.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：NATURE PUBLISHING GROUP  

In this study, critical signaling pathway required for the stretch induced morphological changes of human umbilical endothelial cells (HUVECs) was investigated. Uniaxial cyclic stretch (1 Hz, 20% in length) of the cells cultured on an elastic silicon membrane induced a gradual morphological change in the cells from a polygonal shape to an elongated spindle-like shape whose long axis was aligned perpendicular to the stretch axis, We found that protein tyrosine phosphorylation of cellular proteins increased and peaked at 20 min in response to cyclic stretch. Either treatment of cells with gadolinium (Gd3+), a potent blocker for stretch-activated channels, or removal of extracellular Ca2+ blocked the tyrosine phosphorylation of the proteins, suggesting that stretch-activated (SA) ion channels regulated stretch specific tyrosine phosphorylation, The major phosphorylated proteins had molecular masses of approximately 120-135 kDa, and 70 kDa, Immunoprecipitation experiments revealed that paxillin, focal adhesion kinase (pp125(FAK)) and pp130(CAS) were included in the 70 kDa and 120-135 kDa bands, respectively, The morphological change was inhibited by herbimycin A and genistein, inhibitors of tyrosine kinases, suggesting that tyrosine phosphorylation was required for the morphological change, In addition, the kinase activation of pp125(FAK) was observed in response to cyclic stretch, Moreover, suppression of pp125(FAK) expression by the antisense phosphorothioate oligodeoxynucleotides (S-ODN) in HUVECs resulted in inhibition of tyrosine phosphorylation of paxillin and the stretch-dependent morphological changes. These results suggest that an activation of tyrosine kinase(s) by an increase in intracellular Ca2+ and pp125(FAK) play a critical role in the unique morphological change specifically observed in endothelial cells subjected to uni-axial cyclic stretch.

DOI： 10.1038/sj.onc.1201950

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The present work was designed to elucidate the involvement of Ca2+permeable stretch-activated (SA) channels in the orienting response of endothelial cells to uniaxial cyclic stretch. Endothelial cells from human umbilical vein were cultured on an elastic silicone membrane and subjected to uniaxial cyclic stretch (120% in length, 1 Hz). The cells started to change their morphology 15 min after the onset of stretch, and &gt
90% of the cells oriented perpendicularly to the stretch axis after 2 h. Associated with the orienting response, cell elongation proceeded with a slower rate. Both of the orientating and elongating responses were largely inhibited by the removal of external Ca2+ or by Gd3+, a potent blocker for the SA channel, but not by nifedipine. Intracellular Ca2+ concentration ([Ca2+](i)) transiently increased in response to uniaxial stretch, and the basal [Ca2+](i) gradually increased during cyclic stretch. This Ca2+ response was inhibited by the removal of extracellular Ca2+ or by the addition of Gd3+. These results suggest that stretch-dependent Ca2+ influx through SA channels is essential in the stretch-dependent cell orientation and elongation.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

The present work was designed to elucidate the involvement of Ca2+-permeable stretch-activated (SA) channels in the orienting response of endothelial cells to uniaxial cyclic stretch. Endothelial cells from human umbilical vein were cultured on an elastic silicons membrane and subjected to uniaxial cyclic stretch (120% in length, 1 Hz). The cells started to change their morphology 15 min after the onset of stretch, and &gt;90% of the cells oriented perpendicularly to the stretch axis after 2 h. Associated with the orienting response, cell elongation proceeded with a slower rate. Both of the orientating and elongating responses were largely inhibited by the removal of external Ca2+ or by Gd3+, a potent blocker for the SA channel, but not by nifedipine. Intracellular Ca2+ concentration ([Ca2+](i)) transiently increased in response to uniaxial stretch, and the basal [Ca2+](i) gradually increased during cyclic stretch. This Ca2+ response was inhibited by the removal of extracellular Ca2+ or by the addition of Gd3+. These results suggest that stretch-dependent Ca2+ influx through SA channels is essential in the stretch-dependent cell orientation and elongation.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC ELSEVIER SCIENCE  

The effect of uni-axial cyclic mechanical stretch on the expression of cyclooxygenases (COX) was investigated in a human lung fibroblast cell line (TIG-1). In response to uni-axial cyclic stretch, the level of COX2 mRNA significantly increased and peaked at 3 h (9.09 +/- 3.82-fold, mean +/- standard error, n = 6, compared with that at 1 h). The level of the expression of COX2 protein peaked at 6 h, whereas the level of COX1 protein was not significantly changed. The involvement of stretch-activated (SA) channel was investigated in the stretch-induced COX2 production. The application of Gd3+, a blocker for SA channel, or the removal of extracellular Ca2+ inhibited the production of COX2 mRNA without any effect on the production of COX1 or GAPDH mRNA. These data strongly suggest that COX2 expression is up-regulated by uni-axial cyclic stretch via the activation of SA channel in human lung fibroblasts. (C) 1998 Academic Press.

DOI： 10.1006/bbrc.1998.8335

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER ASSOC CANCER RESEARCH  

Cell adhesion to the extracellular matrix appears to trigger a cascade of intracellular signalings. We have shown previously that treatment of ovarian cancer cells with peritoneal conditioned medium or purified fibronectin (FN) activated matrix metalloproteinase 9 secretion and, thereby, cancer cell invasion, By use of antisense oligonucleotides to focal adhesion kinase (FAK) and a dominant-negative mutant of ras (S17Nras), we found that both FAK and c-Ras were required for the activation of matrix metalloproteinase 9 secretion by FN. In addition, both antisense oligonucleotides to FAR and S17Nras inhibited mitogen-activated protein kinase activation hy FN treatment, suggesting the involvement of mitogen-activated protein kinase in the FN-dependent signaling.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER LUNG ASSOC  

Tumor cells expressing the herpes simplex virus-thymidine kinase (HSV-tk) gene become sensitive to ganciclovir (GCV), and the phenomenon by which tumor cells surrounding the HSV-tk expressing cells also become sensitive to CCV is known as the "bystander effect." The purpose of this study was to investigate the bystander effect in human lung-cancer cell lines, and the role of gap-junctional intercellular communication as the mechanism responsible for it. Gap-junctional intercellular communication was measured both with a dye-transfer assay involving single-cell microinjection of Lucifer Yellow and with a PKH26/calcein-AM double-dye-transfer assay. Significant bystander tumoricidal effect was observed in lung-cancer cell lines when cultured cells contained only 10% HSV-tk expressing cells. This was also observed to occur with cell lines of different origin or from different species. Although gap-junctional intercellular communication characterized by rapid transfer of Lucifer Yellow was not observed, we did detect gap-junctional communication marked by the slow transfer of calcein-AM in lung-cancer cell lines. However, neither an inhibitor (I-octanol) nor an enhancer (all trans-retinoic acid [ATRA]) of gap-junctional communication affected the extent of the bystander effect. These findings suggest that low levels of gap-junctional communication may be efficient for producing the bystander effect in lung-cancer cells, or chat other mechanisms may underlie this effect. Although gap-junctional communication may play an important role in generating the bystander effect in tumor cells expressing the HSV-tk gene, further knowledge of the mechanism of this effect may help improve the treatment of lung cancer with an HSV-tk system.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS  

The effect of uni-axial cyclic mechanical stretch on the expression of the adhesion protein integrin was investigated. Human umbilical endothelial cells (HUVECs) cultured an fibronectin coated silicon membranes were subjected to uni-axial cyclic stretch, The level of expression of integrin beta(3) mRNA was found to be increased and peaked at 4 hours in response to cyclic stretch using a semiquantitative RT-PCR method. The increased level of the integrin mRNA from stretched HUVECs remained higher than that ii om non-stretched controls. The amount of integrin beta(3) also increased and peaked at 12 hr, Immuno-fluorescent microscopy revealed that the amount of integrin beta(3) adhesions increased in stretched HUVECs compared with that in non-stretched HUVECs. These results suggest that uni-axial cyclic stretch up-regulates the expression of integrin beta(3). This increase in integrin beta(3), may enhance the adhesiveness to the substratum and contribute to the protection of HUVECs against being peeled off from the vessel wall. (C) 1997 Academic Press.

DOI： 10.1006/bbrc.1997.7364

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER  

We investigated the signaling mechanism of stretch-induced cell remodeling in human umbilical vein endothelial cells (HUVECs). Freshly dissociated HUVECs were cultured on an elastic silicon membrane and subjected to uniaxial cyclic stretch (20% in length, 1Hz). The cells started to change their morphology as early as 15 min after stretch onset, and most cells eventually aligned perpendicularly to the stretch axis within Ih. This remodeling was dependent on the increase in intracellular calcium concentration ([Ca2+](i)) via a Ca2+-permeable stretch-activated (SA) channel. During the process of remodeling, extensive rearrangement of stress fibers and focal adhesions was observed, which may be close to the final step in the intracellular signaling cascade. This event was [Ca2+](i)-dependent, suggesting the existence of a Ca2+-dependent intermediate cascade that links [Ca2+](i) to the rearrangement of cytoskeletons and focal adhesions. We found that some proteins, including pp125(FAK) (focal adhesion kinase) and paxillin, were tyrosine phosphorylated during cyclic stretch in a Ca2+-dependent manner. Inhibition of this tyrosine phosphorylation prohibited the stretch-dependent rearrangement of cytoskeletons and focal adhesions as well as the remodeling. Finally the tyrosine kinase src, which could phosphorylate pp125(FAK), was found to be activated in a [Ca2+](i)-dependent way during stretch. All of the above molecular events were consistently Ca2+-dependent, which led us to propose the signaling cascade: SA channel activation --&gt; [Ca2+](i) increase --&gt; src activation --&gt; protein tyrosine phosphorylation --&gt; rearrangement of cytoskeletons and focal adhesions --&gt; cell remodeling.

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記述言語：英語   出版者・発行元：名古屋大学  

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記述言語：英語   出版者・発行元：名古屋大学  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

1. A characteristic plateau pattern was observed in the rate of afferent discharges during ramp-and-hold stretch of spindles isolated from semitendinosus muscles of frogs. The plateau pattern was more frequent in summer frogs (84%) than winter frogs (11%).
2. The plateau pattern consisted of a discharge rate around 120 imp/s at the end of dynamic stretch, followed by second and third steps of plateau rates around 60 and 40 imp/s, respectively. The intervals of impulses in lower steps were approximately n times those of the top step.
3. The plateau pattern was not sensitive to cutting extracapsular myelinated branches or lowering temperature from 23 to 12-degrees-C. However, the number of the plateau was reduced in both cases.
4. Application of depolarizing current to the sensory terminal abolished the plateau pattern. In contrast, in spindles that did not show a plateau pattern, hyperpolarizing current induced such a pattern.
5. Calcium channel blockers and protein kinase C inhibitors abolished the plateau pattern. The plateau pattern could be established in quiescent spindles by drugs eliciting Ca2+ entry, raising cytosolic-free Ca2+, and activating protein kinase C.
6. The most striking aspect of the present study is the stability in the discharge rate at each step of the plateau, irrespective of different experimental conditions. This suggests that the spindle sensory terminal possesses a stable intrinsic rhythm generator in excitation, of which maximum frequency is 120 imp/s. The generator seems to be triggered by stretch stimulus and to be regulated by cytoplasmic Ca2+ and protein kinase C.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

Endothelial cells are subjected to shear stresses by blood flow, normal stresses by blood pressure, and stretch by vessel expansion. These forces are known to induce secretions of several vasoactive substances probably via internal calcium mobilization (R. F. Furchgott. Circ. Res. 53: 557-573, 1983; M. J. Peach, A. L. Loeb, H. A. Singer, and J. Saye. Hypertension Dallas 7, Suppl. I: I-94-1-100, 1985.). Here we report that stretching cellular membranes increased intracellular Ca2+ concentration ([Ca2+]i) in human umbilical endothelial cells cultured on silicon membranes. Upon application of a stretch pulse (3-s duration), [Ca2+]i increased rapidly and decayed slowly. The following results suggest that this increase arises from Ca2+ entry through stretch-activated (SA) channels: 1) the Ca2+ response disappeared when extracellular Ca2+ was removed; 2) gadolinium (Gd3+), a blocker for cation-selective SA channels, blocked the response but nifedipine did not; and 3) externally applied Mn2+, which is known to permeate mechanosensitive channels but not Ca2+ channels, entered the intracellular space immediately after an application of mechanical stretch. The increase in [Ca2+]i was found to consist of at least two components: an initial fast component and a delayed slower component. Ryanodine inhibited the slow component. It is suggested that stretching the membrane primarily induced extracellular Ca2+ entry through SA channels followed by Ca2+ releases from intracellular Ca2+ stores.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：CENTER ACADEMIC PUBL JAPAN  

Stretch activated (SA) channels are believed to be activated by tension in the membrane generated by membrane stretch. However, very few studies have been made on the quantitative estimation of the tension during membrane stretch. Here we present a method to evaluate the tension both in patch clamped and intact cell-membranes. The tension in patch clamped membranes was calculated from Laplace's law by knowing transmembrane pressure and the radius of patch-curvature. We also provide a simpler version for calculating the tension from the pressure and pipette radius. The tension in intact cell membranes was calculated from Hook's law based on the measurement of changes in cell surface area. The estimated tension required for activating SA channels in both types of membranes was found to be comparable suggesting that,the SA channel acts as a physiological mechanotransducer in intact cells.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：AMER PHYSIOLOGICAL SOC  

The nonapeptide bradykinin (BK) excites a subset of dorsal root ganglion (DRG) neurons with putative nociceptive functions by stimulating an inward cation current. In addition, BK stimulates various intracellular signaling pathways including an elevation of intra-cellular Ca2+. In a DRG neuron x neuroblastoma hybrid cell (F-11), BK stimulates similar increases in intracellular [Ca2+] and inward current but also elicits a large transient outward current through Ca2+-activated K channels. We have investigated the mechanisms underlying differential expression of outward current responses in the two cell types at the single channel level. Although K(Ca) channel activity appears in inside-out patches from both cells exposed to Ca2+, BK applied to the extrapatch membrane of cell-attached patches activates K(Ca) channels in F-11 but not DRG neurons. Whereas single K(Ca) channels are quantitatively similar in terms of conductance, voltage-dependence, and sensitivity to tetraethylammonium, they differ in sensitivity to intracellular Ca2+. Channel activation in both cells requires at least four Ca2+ ions, but half-maximal activation occurs at slightly higher [Ca2+] for DRG neurons. The shift in the Ca2+ dose-response curve combined with the steep [Ca2+] dependence of channel open probability makes it less likely that a BK-induced rise in internal [Ca2+] induced will trigger a transient outward current and resultant hyperpolarization in a DRG neuron.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

This article presents a brief review on the electrophysiological analysis of the structural aspects of the voltage-dependent SR (sarcoplasmic reticulum) K+ channel. In the first half, early attempts to determine the physical dimensions of the ion conducting mechanism such as the mouth, narrow tunnel, or ion selective filter of the channel, are reviewed. The depicted cartoon of the SR K+ channel, as an extremely short, busy district with a big mouth on each side, is quite similar to the recently-obtained reconstructed structural image of the acetylcholine receptor channel. In the latter half, we introduce our recent attempts to draw a physical image of the gating mechanism of the SR K+ channel. We examined, for example, the location of the gate and the voltage sensor, and the relationship between them. It is suggested that the gate and the sensor are connected tightly and that the sensor would be exposed to the surface of the lumen side of SR when the gate opens. Finally, the issue of substates in SR K+ channel is discussed. It is implied that the substate-conductances reflect a partial occlusion of the pore by an intermediate-open gate.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER VERLAG  

DOI： 10.1007/BF01868639

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/0921-8696(90)90005-N

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担当ページ：pp243-262   記述言語：英語

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記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）   出版者・発行元：公益社団法人 日本生体医工学会  

<p>近年メカノバイオロジーを基盤とした研究手法は、様々な疾患の成因解明と治療法開発というメカノメディスンへと昇華し始めている。本講演はメカノ再生医療とメカノ生殖医療のトランスレーショナルリサーチの展開による、臨床利用可能な革新的次世代メカノ医療技術について紹介する。やけどなど皮膚の損傷に対し再生医療の応用が期待されている。我々は独自に開発した細胞培養器を用い、表皮角化細胞と皮膚線維芽細胞の共培養を行って伸展刺激を付加したところ、表皮層の増高と基底膜形成の促進が認められた。また心不全患者に対しては心臓再生医療の応用が期待されている。心臓再生医療では、幹細胞に対する伸展刺激は細胞分化能や生着性を変化させて細胞治療の効果を改善すると考えられてきたが、幹細胞より直接遊離するエクソソームが様々なパラクライン因子やmicro RNAを分泌することで、in vivoでの細胞移植治療の効果を向上させていることが明らかとなった。生殖補助医療においては、体外受精卵の生育率の低さが大きな問題である。我々は受精卵にメカニカルストレスを付加する傾斜胚培養システムを用いて受精卵培養したところ、受精卵の胚盤胞到達率が静置培養区と比較して向上した。遺伝子発現網羅的解析の結果から、この現象は胚盤葉上層の遺伝子発現変化に起因することが示唆された。今後も各分野における機械刺激応答のメカニズム解明に注力するとともに、メカノ医療技術の臨床応用を進めていく。</p>

DOI： 10.11239/jsmbe.55Annual.340

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記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）  

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記述言語：英語   掲載種別：書評論文，書評，文献紹介等   出版者・発行元：American Institute of Mathematical Sciences  

Cell surface receptors are involved in numerous important biological processes including embryogenesis, tissue differentiation, and cellular homeostasis. Among them, mechanosensitive ion channels play an essential role in cellular functions of every cell including neurons, cardiomyocytes, and osteocytes. Here, we discuss types, roles, structures, and biophysical factors that affect the functions of mechanosensitive ion channels.

DOI： 10.3934/biophy.2016.1.63

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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DOI： 10.11392/jsao.43.206

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：CELL PRESS  

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記述言語：日本語   出版者・発行元：日本生物工学会  

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10518796

記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   出版者・発行元：(公社)日本矯正歯科学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER THORACIC SOC  

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記述言語：日本語  

DOI： 10.1274/jmor.28.174

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：CELL PRESS  

DOI： 10.1016/j.bpj.2009.12.2986

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：CELL PRESS  

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記述言語：日本語   出版者・発行元：(一社)日本生殖医学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：WILEY-BLACKWELL PUBLISHING, INC  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：OXFORD UNIV PRESS  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：SPRINGER TOKYO  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：SPRINGER TOKYO  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：SPRINGER TOKYO  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：日本語   出版者・発行元：社団法人日本生体医工学会  

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記述言語：英語   出版者・発行元：社団法人日本循環器学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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DOI： 10.1380/jsssj.28.204

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

イオン感応性電界効果トランジスタ(ISFET)を用いたpHおよびPCO_2センサによるCO_2、NaHCO_3、乳酸(LA)分泌量のリアルタイム測定法を開発した。センサの感応部容積は0.8μL以下と微小で1μLの基質溶液の計測が可能であり、全pH変化及びその内のCO_2の占める割合をリアルタイムにモニタリングし、培養細胞の呼吸・代謝状態を評価出来た。細胞からの主な代謝産物は、CO_2、HCO_3^-,乳酸(LA)であるので、平衡式からCO_2+LA,LA-HCO_3^-,CO_2+HCO_3^-といった関係を数値化することにより大動脈血管平滑筋や血管内皮のCO_2産生速度を定量した。

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その他リンク： http://search.jamas.or.jp/link/ui/2007008183

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DOI： 10.4044/joma1947.118.1_23

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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記述言語：日本語   掲載種別：書評論文，書評，文献紹介等  

Cells can respond to a variety of mechanical stimuli such as tension, pressure, and shear stress. However, the mechanisms of mechanotransduction are largely unknown. The major reason for this lies in the ambiguity of the molecular entity of cell mechanosensors. Currently only MS (mechanosensitive) channels conform to an established class of mechanosensors due to the firm and detailed analyses by electrophysiolgy. Although molecular structures of MS channels are known for limited members, higher order structures of bacterial MS channels have been resolved and their detailed structure-function studies are in progress. In contrast, molecular and biophysical analyses of eukaryote MS channels, which may attract much attention, are yet not well-studied. Although many candidate molecules have been proposed as the cell mechanosensor, currently only 2-pore-domain K channels (TREK/TRAAK) and SAKCA, a new class of MS channel introduced here, may be the subjects eligible for rigorous electrophysiological analyses. On the other hand, lack of specific blockers to MS channels is another reason why the progress in this field is slow. Gadolinium (Gd 3+) has been extensively used as a potent blocker of MS channels, but its nonspecific actions have limited its usefulness. Very recently, a promising 35 mer peptide, which can be more specific for MS channels, named GsMTx-4 has been isolated from spider venom. This peptide is interesting because it inhibits stretch-induced atrial fibrillation, which may involve MS channel activation and thus can be used as a basis for developing a new class of drugs to cure heart failure. This short review deals with recent progresses in MS channel studies and the structure-function of SAKCA, a recently cloned MS channel from heart, as well as its interaction with the new MS channel blocker GsMTx-4.

DOI： 10.1254/fpj.124.301

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：JAPANESE PHARMACOLOGICAL SOC  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：JAPANESE PHARMACOLOGICAL SOC  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：W B SAUNDERS CO  

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記述言語：英語   掲載種別：速報，短報，研究ノート等（学術雑誌）   出版者・発行元：AMER ASSOC ADVANCEMENT SCIENCE  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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DOI： 10.11477/mf.2425902489

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記述言語：日本語  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：LIPPINCOTT WILLIAMS & WILKINS  

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記述言語：日本語   出版者・発行元：一般社団法人日本生物物理学会  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER DIABETES ASSOC  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BIOPHYSICAL SOCIETY  

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DOI： 10.11239/jsmbe1963.36.287

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：AMER SOC CELL BIOLOGY  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：CELL PRESS  

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