Abstract 273: P2Y2 Receptor-Mediated Lymphotoxin-α Secretion Regulates ICAM-1 Expression in Smooth Muscle Cells

Rationale: Single nucleotide polymorphism (SNP) in the LGASL2 galectin-2 (Gal-2) gene leads to altered secretion of lymphotoxin-α (LT-α) and is associated with coronary artery disease. Objective:Our aim was to determine whether factors other than genetic variations in LGASL2 regulate LT-α release and to define the role of this pro-inflammatory in vascular smooth muscle cells (SMC). Methods and results: The proinflammatory cytokine lymphotoxin-alpha (LTA) is thought to contribute to the pathogenesis of atherosclerosis. However, the mechanisms that regulate its expression in VSMC are poorly understood. The ability of exogenous nucleotides to stimulate LTA production was evaluated in VSMC by ELISA. The P2Y 2 nucleotide receptor (P2Y 2 R) agonist UTP stimulates a strong and sustained release of LTA from wild-type but not P2Y 2 R -/- SMC. Assessment of LTA gene transcription by LTA promoter-luciferase construct indicated that LTA levels are controlled at the level of transcription. We show using RNAi techniques that knockdown of the actin-binding protein filamin-A (FLNa) severely impaired nucleotide-induced Rho activation and consequent Rho-mediated LTA secretion. Re-introduction of FLNa in FLNa RNAi SMC rescued UTP-induced LTA expression. In addition, we found UTP-stimulated LTA secretion is not sensitive to brefeldin A (BFA), which blocks the formation of vesicles involved in protein transport from the ER to the Golgi apparatus, suggesting that P2Y 2 R/filamin-mediated secretion of LTA is independent of the ER/Golgi secretory vesicle route. Furthermore, UTP selectively induces ICAM-1 expression in WT but not SMC expressing a truncated P2Y 2 R deficient in LTA secretion. Conclusion: These data suggest that P2Y 2 R recruits FLNa to provide a cytoskeletal scaffold necessary for Rho signaling pathway upstream of LTA release and subsequent stimulation of ICAM-1 expression on VSMC.

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Transgelin-1 (SM22α) interacts with actin stress fibers and podosomes in smooth muscle cells without using its actin binding site

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2018.09.176 ◽

2018 ◽

Vol 505 (3) ◽

pp. 879-884 ◽

Cited By ~ 9

Author(s):

Tsubasa S. Matsui ◽

Akihiro Ishikawa ◽

Shinji Deguchi

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Binding Site ◽

Muscle Cells ◽

Stress Fibers ◽

Actin Binding ◽

Actin Binding Site ◽

Actin Stress Fibers

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TGFβ, smooth muscle cells and coronary artery disease: a review

Cellular Signalling ◽

10.1016/j.cellsig.2018.09.004 ◽

2019 ◽

Vol 53 ◽

pp. 90-101 ◽

Cited By ~ 15

Author(s):

Emma L. Low ◽

Andrew H. Baker ◽

Angela C. Bradshaw

Keyword(s):

Coronary Artery Disease ◽

Smooth Muscle ◽

Coronary Artery ◽

Smooth Muscle Cells ◽

Muscle Cells ◽

Artery Disease

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Cyclic AMP-Rap1A signaling mediates cell surface translocation of microvascular smooth muscle α2C-adrenoceptors through the actin-binding protein filamin-2

AJP Cell Physiology ◽

10.1152/ajpcell.00221.2012 ◽

2013 ◽

Vol 305 (8) ◽

pp. C829-C845 ◽

Cited By ~ 22

Author(s):

Hanaa K. B. Motawea ◽

Selvi C. Jeyaraj ◽

Ali H. Eid ◽

Srabani Mitra ◽

Nicholas T. Unger ◽

...

Keyword(s):

Smooth Muscle ◽

Plasma Membrane ◽

Cyclic Amp ◽

Cell Surface ◽

Smooth Muscle Cells ◽

Blood Vessels ◽

Muscle Cells ◽

Small Gtpase ◽

Actin Binding ◽

Surface Translocation

The second messenger cyclic AMP (cAMP) plays a vital role in vascular physiology, including vasodilation of large blood vessels. We recently demonstrated cAMP activation of Epac-Rap1A and RhoA-Rho-associated kinase (ROCK)-F-actin signaling in arteriolar-derived smooth muscle cells increases expression and cell surface translocation of functional α2C-adrenoceptors (α2C-ARs) that mediate vasoconstriction in small blood vessels (arterioles). The Ras-related small GTPAse Rap1A increased expression of α2C-ARs and also increased translocation of perinuclear α2C-ARs to intracellular F-actin and to the plasma membrane. This study examined the mechanism of translocation to better understand the role of these newly discovered mediators of blood flow control, potentially activated in peripheral vascular disorders. We utilized a yeast two-hybrid screen with human microvascular smooth muscle cells (microVSM) cDNA library and the α2C-AR COOH terminus to identify a novel interaction with the actin cross-linker filamin-2. Yeast α-galactosidase assays, site-directed mutagenesis, and coimmunoprecipitation experiments in heterologous human embryonic kidney (HEK) 293 cells and in human microVSM demonstrated that α2C-ARs, but not α2A-AR subtype, interacted with filamin. In Rap1-stimulated human microVSM, α2C-ARs colocalized with filamin on intracellular filaments and at the plasma membrane. Small interfering RNA-mediated knockdown of filamin-2 inhibited Rap1-induced redistribution of α2C-ARs to the cell surface and inhibited receptor function. The studies suggest that cAMP-Rap1-Rho-ROCK signaling facilitates receptor translocation and function via phosphorylation of filamin-2 Ser2113. Together, these studies extend our previous findings to show that functional rescue of α2C-ARs is mediated through Rap1-filamin signaling. Perturbation of this signaling pathway may lead to alterations in α2C-AR trafficking and physiological function.

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The Emerging Role of Long Non-coding RNAs and Circular RNAs in Coronary Artery Disease

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.632393 ◽

2021 ◽

Vol 8 ◽

Author(s):

Soudeh Ghafouri-Fard ◽

Mahdi Gholipour ◽

Mohammad Taheri

Keyword(s):

Coronary Artery Disease ◽

Smooth Muscle ◽

Coronary Artery ◽

Smooth Muscle Cells ◽

Muscle Cells ◽

Cell Types ◽

Circular Rnas ◽

Numerous Cell ◽

Non Coding Rnas ◽

Artery Disease

Coronary artery disease (CAD) is a common disorder caused by atherosclerotic processes in the coronary arteries. This condition results from abnormal interactions between numerous cell types in the artery walls. The main participating factors in this process are accumulation of lipid deposits, endothelial cell dysfunction, macrophage induction, and changes in smooth muscle cells. Several lines of evidence underscore participation of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in the pathogenesis of CAD. Several lncRNAs such as H19, ANRIL, MIAT, lnc-DC, IFNG-AS1, and LEF1-AS1 have been shown to be up-regulated in the biological materials obtained from CAD patients. On the other hand, Gas5, Chast, HULC, DICER1-AS1, and MEG3 have been down-regulated in CAD patients. Meanwhile, a number of circRNAs have been demonstrated to influence function of endothelial cells or vascular smooth muscle cells, thus contributing to the pathogenesis of CAD. In the current review, we summarize the function of lncRNAs and circRNAs in the development and progression of CAD.

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Role of the signal transducer and activator of transcription 3 protein in the proliferation of vascular smooth muscle cells

Vascular ◽

10.1177/1708538120929504 ◽

2020 ◽

Vol 28 (6) ◽

pp. 821-828

Author(s):

Hong-Xia Tang ◽

Xu-Ping Qin ◽

Jie Li

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Muscle Cells ◽

Signal Transducer ◽

Vsmc Proliferation ◽

Stat3 Signaling Pathway ◽

Artery Disease ◽

Transcription 3

Objectives Cardiovascular disease (CVD) remains the primary cause of morbidity and mortality worldwide. The abnormal proliferation of vascular smooth muscle cells (VSMCs) is a key event in the pathogenesis of CVD. The functional and phenotypic changes in vascular cells are mediated by complex signaling cascades that initiate and control genetic reprogramming. Many studies have demonstrated that signal transducer and activator of transcription 3 (STAT3) regulates a diverse array of functions relevant to atherosclerosis. Methods In this review, we summarize the studies on the STAT3-mediated proliferation of VSMCs and subsequent CVDs such as hypertension, atherosclerosis, stroke, coronary artery disease, and myocardial infarction. Furthermore, we describe the general background of STAT3, its structure, function and regulation as well as the STAT3 signaling pathway. Finally, we highlight some potential issues and propose some solutions to these issues. Results and conclusions: STAT3 activation promotes the proliferation of VSMCs by regulating the transcription of genes. Studying the mechanism of VSMC proliferation induced by the STAT3 pathway is valuable for finding therapeutic targets for CVD.

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Autocrine ATP release coupled to extracellular pyrophosphate accumulation in vascular smooth muscle cells

AJP Cell Physiology ◽

10.1152/ajpcell.00619.2008 ◽

2009 ◽

Vol 296 (4) ◽

pp. C828-C839 ◽

Cited By ~ 33

Author(s):

Domenick A. Prosdocimo ◽

Dezmond C. Douglas ◽

Andrea M. Romani ◽

W. Charles O'Neill ◽

George R. Dubyak

Keyword(s):

Smooth Muscle ◽

Vascular Smooth Muscle ◽

Smooth Muscle Cells ◽

Vascular Smooth Muscle Cells ◽

Atp Release ◽

Brefeldin A ◽

Muscle Cells ◽

Rat Aorta ◽

Inorganic Pyrophosphate ◽

Inhibition Of Proliferation

Extracellular inorganic pyrophosphate (PPi) is a potent suppressor of physiological calcification in bone and pathological calcification in blood vessels. Ectonucleotide pyrophosphatase/phosphodiesterases (eNPPs) generate PPi via the hydrolysis of ATP released into extracellular compartments by poorly understood mechanisms. Here we report that cultured vascular smooth muscle cells (VSMC) from rat aorta generate extracellular PPi via an autocrine mechanism that involves ATP release tightly coupled to eNPP activity. The nucleotide analog β,γ-methylene ATP (MeATP or AMPPCP) was used to selectively suppress ATP metabolism by eNPPs but not the CD39-type ecto-ATPases. In the absence of MeATP, VSMC generated extracellular PPi to accumulate ≥600 nM within 2 h while steadily maintaining extracellular ATP at 1 nM. Conversely, the presence of MeATP completely suppressed PPi accumulation while increasing ATP accumulation. Probenecid, which inhibits PPi efflux dependent on ANK, a putative PPi transporter or transport regulator, reduced extracellular PPi accumulation by approximately twofold. This indicates that autocrine ATP release coupled to eNPP activity comprises ≥50% of the extracellular PPi-generating capacity of VSMC. The accumulation of extracellular PPi and ATP was markedly attenuated by reduced temperature but was insensitive to brefeldin A, which suppresses constitutive exocytosis of Golgi-derived secretory vesicles. The magnitude of extracellular PPi accumulation in VSMC cultures increased with time postplating, suggesting that ATP release coupled to PPi generation is upregulated as cultured VSMC undergo contact-inhibition of proliferation or deposit extracellular matrix.

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Immunoelectron microscopic localization of fibronectin in the smooth muscle layer of mouse small intestine.

Journal of Histochemistry & Cytochemistry ◽

10.1177/35.4.3546487 ◽

1987 ◽

Vol 35 (4) ◽

pp. 411-417 ◽

Cited By ~ 7

Author(s):

K Kurisu ◽

Y Ohsaki ◽

K Nagata ◽

T Kukita ◽

H Yoshikawa ◽

...

Keyword(s):

Extracellular Matrix ◽

Smooth Muscle ◽

Small Intestine ◽

Smooth Muscle Cells ◽

Basal Lamina ◽

Muscle Cells ◽

Muscle Layer ◽

Secretory Vesicle ◽

Smooth Muscle Layer ◽

Mouse Small Intestine

We studied the ultrastructural distribution of fibronectin in the smooth muscle layer of mouse small intestine with affinity-purified antibodies using the immunogold technique. Fibronectin was present over the pericellular area extending from the cell membrane to the extracellular matrix beyond the basal lamina. Distribution of the glycoprotein over the pericellular area was heterogeneous, i.e., it was localized more abundantly in the narrow space between smooth muscle cells, the gaps having a width of 60-80 nm where the two dense bands in adjacent cells matched each other. Such localization suggests that fibronectin contributes to cell adhesion. Within the basement membrane, gold label was localized both in lamina lucida and lamina densa, more densely in the latter than in the former. Fibronectin was also co-distributed with collagen fibers in the extracellular matrix. Within smooth muscle cells, gold particles were observed on rough endoplasmic reticulum and secretory vesicle-like structures. These results suggest that smooth muscle cells synthesize fibronectin and secrete it as a component of the basal lamina and extracellular matrix.

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