scholarly journals Spatially selective myosin regulatory light chain regulation is absent in dedifferentiated vascular smooth muscle cells but is partially induced by fibronectin and Klf4

2019 ◽  
Vol 316 (4) ◽  
pp. C509-C521 ◽  
Author(s):  
Tsubasa S. Matsui ◽  
Shinji Deguchi
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Light Chain ◽  
Muscle Cells ◽  
Cell Types ◽  
Myosin Regulatory Light Chain ◽  
Phosphorylation State ◽  
Spatial Regulation

The phosphorylation state of myosin regulatory light chain (MRLC) is central to the regulation of contractility that impacts cellular homeostasis and fate decisions. Rho-kinase (ROCK) and myosin light chain kinase (MLCK) are major kinases for MRLC documented to selectively regulate MRLC in a subcellular position-specific manner; specifically, MLCK in some nonmuscle cell types works in the cell periphery to promote migration, while ROCK does so at the central region to sustain contractility. However, it remains unclear whether or not the spatially selective regulation of the MRLC kinases is universally present in other cell types, including dedifferentiated vascular smooth muscle cells (SMCs). Here, we demonstrate the absence of the spatial regulation in dedifferentiated SMCs using both cell lines and primary cells. Thus, our work is distinct from previous reports on cells with migratory potential. We also observed that the spatial regulation is partly induced upon fibronectin stimulation and Krüppel-like factor 4 overexpression. To find clues to the mechanism, we reveal how the phosphorylation state of MRLC is determined within dedifferentiated A7r5 SMCs under the enzymatic competition among three major regulators ROCK, MLCK, and MRLC phosphatase (MLCP). We show that ROCK, but not MLCK, predominantly regulates the MRLC phosphorylation in a manner distinct from previous in vitro-based and in silico-based reports. In this ROCK-dominating cellular system, the contractility at physiological conditions was regulated at the level of MRLC diphosphorylation, because its monophosphorylation is already saturated. Thus, the present study provides insights into the molecular basis underlying the absence of spatial MRLC regulation in dedifferentiated SMCs.

scholarly journals 2-Methoxyestradiol blocks the RhoA/ROCK1 pathway in human aortic smooth muscle cells

2015 ◽  
Vol 309 (12) ◽  
pp. E995-E1007 ◽  
Author(s):  
Lisa Rigassi ◽  
Federica Barchiesi Bozzolo ◽  
Eliana Lucchinetti ◽  
Michael Zaugg ◽  
Jürgen Fingerle ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Molecular Mechanisms ◽  
Muscle Cells ◽  
Myosin Phosphatase ◽  
Downstream Signaling

2-Methoxyestradiol (2-ME), a metabolite of estradiol with little affinity for estrogen receptors, inhibits proliferation of vascular smooth muscle cells; however, the molecular mechanisms underlying this effect are incompletely understood. Our previous work shows that 2-ME inhibits initiation (blocks phosphorylation of ERK and Akt) and progression (reduces cyclin expression and increases expression of cyclin inhibitors) of the mitogenic pathway and interferes with mitosis (disrupts tubulin organization). Because the RhoA/ROCK1 pathway (RhoA → ROCK1 → myosin phosphatase targeting subunit → myosin light chain) is involved in cytokinesis, herein we tested the concept that 2-ME also blocks the RhoA/ROCK1 pathway. Because of the potential importance of 2-ME for preventing/treating vascular diseases, experiments were conducted in female human aortic vascular smooth muscle cells. Microarray transcriptional profiling suggested an effect of 2-ME on the RhoA/ROCK1 pathway. Indeed, 2-ME blocked mitogen-induced GTP-bound RhoABC expression and membrane-bound RhoA, suggesting interference with the activation of RhoA. 2-ME also reduced ROCK1 expression, suggesting reduced production of the primary downstream signaling kinase of the RhoA pathway. Moreover, 2-ME inhibited RhoA/ROCK1 pathway downstream signaling, including phosphorylated myosin phosphatase targeting subunit and myosin light chain; the ROCK1 inhibitor H-1152 mimicked these effects of 2-ME; both 2-ME and H-1152 blocked cytokinesis. 2-ME also reduced the expression of tissue factor, yet another downstream signaling component of the RhoA/ROCK1 pathway. We conclude that 2-ME inhibits the pathway RhoA → ROCK1 → myosin phosphatase targeting subunit → myosin light chain, and this likely contributes to the reduced cytokinesis in 2-ME treated HASMCs.

scholarly journals Apelin Stimulates Myosin Light Chain Phosphorylation in Vascular Smooth Muscle Cells

2006 ◽  
Vol 26 (6) ◽  
pp. 1267-1272 ◽  
Author(s):  
Tatsuo Hashimoto ◽  
Minoru Kihara ◽  
Junji Ishida ◽  
Nozomi Imai ◽  
Shin-ichiro Yoshida ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Cells ◽  
Myosin Light Chain Phosphorylation

Regulation of calcium-activated chloride channels in smooth muscle cells: a complex picture is emerging

2005 ◽  
Vol 83 (7) ◽  
pp. 541-556 ◽  
Author(s):  
Normand Leblanc ◽  
Jonathan Ledoux ◽  
Sohag Saleh ◽  
Amy Sanguinetti ◽  
Jeff Angermann ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Chloride Channels ◽  
Muscle Cells ◽  
Cell Types ◽  
Dependent Protein Kinase ◽  
Intracellular Ca ◽  
Dependent Protein

Calcium-activated chloride channels (ClCa) are ligand-gated anion channels as they have been shown to be activated by a rise in intracellular Ca2+ concentration in various cell types including cardiac, skeletal and vascular smooth muscle cells, endothelial and epithelial cells, as well as neurons. Because ClCa channels are normally closed at resting, free intracellular Ca2+ concentration (~100 nmol/L) in most cell types, they have generally been considered excitatory in nature, providing a triggering mechanism during signal transduction for membrane excitability, osmotic balance, transepithelial chloride movements, or fluid secretion. Unfortunately, the genes responsible for encoding this class of ion channels is still unknown. This review centers primarily on recent findings on the properties of these channels in smooth muscle cells. The first section discusses the functional significance and biophysical and pharmacological properties of ClCa channels in smooth muscle cells, and ends with a description of 2 candidate gene families (i.e., CLCA and Bestrophin) that are postulated to encode for these channels in various cell types. The second section provides a summary of recent findings demonstrating the regulation of native ClCa channels in vascular smooth muscle cells by calmodulin-dependent protein kinase II and calcineurin and how their fine tuning by these enzymes may influence vascular tone. Key words: calcium-activated chloride channels, vascular smooth muscle cells, ion channels, calmodulin-dependent protein kinase II, calcineurin

Neuropeptide Y (NPY) and NPY receptors in the cardiovascular system: implication in the regulation of intracellular calciumThis paper is one of a selection of papers published in this Special Issue, entitled Young Investigators' Forum.

2007 ◽  
Vol 85 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Danielle Jacques ◽  
Dima Abdel-Samad
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Neuropeptide Y ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cell Types ◽  
Heart Cells ◽  
Microscopy Technique ◽  
Intracellular Ca

The 3-dimensional confocal microscopy technique has allowed us to identify the presence of yet another cardioactive factor and its receptor, namely neuropeptide Y (NPY) and its Y1 receptor, at the level of vascular smooth muscle cells and heart cells including endocardial endothelial cells (EECs). Using this technique, we also demonstrated that NPY is able to induce an increase in both cytosolic and nuclear calcium in all these cell types. Furthermore, besides being expressed at the level of EECs, NPY is also released from these cells following a sustained increase of intracellular Ca2+. This suggests the ability of NPY to contribute to the regulation of the excitation–secretion coupling of EECs and the excitation–contraction coupling of cardiomyocytes and vascular smooth muscle cells.

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