Asynchronous calcium waves in smooth muscle cells

2005 ◽  
Vol 83 (8-9) ◽  
pp. 733-741 ◽  
Author(s):  
Cheng-Han Lee ◽  
Kuo-Hsing Kuo ◽  
Jiazhen Dai ◽  
Cornelis van Breemen
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Smooth Muscle Cells ◽  
Calcium Signaling ◽  
Muscle Cells ◽  
Cell Types ◽  
Tonic Contraction ◽  
Calcium Waves ◽  
Contraction Coupling ◽  
Specialized Form

Asynchronous Ca2+ waves or wave-like [Ca2+]i oscillations constitute a specialized form of agonist-induced Ca2+ signaling that is observed in a variety of smooth muscle cell types. Functionally, it is involved in the contractile regulation of the smooth muscle cells as it signals for tonic contraction in certain smooth muscle cells while causing relaxation in others. Mechanistically, repetitive Ca2+ waves are produced by repetitive cycles of sarcoplasmic reticulum Ca2+ release followed by Ca2+ uptake. Plasmalemmal Ca2+ entry mechanisms are important for providing the additional Ca2+ necessary to maintain proper refilling of the sarcoplasmic reticulum Ca2+ store and support ongoing Ca2+ waves. In this paper, we will review the phenomenon of asynchronous Ca2+ waves in smooth muscle and discuss the scientific and clinical significance of this new understanding.Key words: excitation-contraction coupling, confocal fluoresence microscopy, calcium signaling.

Metabolic modulation of hexokinase association with mitochondria in living smooth muscle cells

1996 ◽  
Vol 270 (2) ◽  
pp. C488-C499 ◽  
Author(s):  
R. M. Lynch ◽  
W. Carrington ◽  
K. E. Fogarty ◽  
F. S. Fay
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Energy State ◽  
Single Cells ◽  
Inverse Correlation ◽  
Muscle Cells ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Similar Distribution ◽  
Apparent Difference

Hexokinase isoform I binds to mitochondria of many cell types. It has been hypothesized that this association is regulated by changes in the concentrations of specific cellular metabolites. To study the distribution of hexokinase in living cells, fluorophore-labeled functional hexokinase I was prepared. After microinjection into A7r5 smooth muscle cells, hexokinase localized to distinct structures identified as mitochondria. The endogenous hexokinase demonstrated a similar distribution with the use of immunocytochemistry. 2-Deoxyglucose elicited an increase in glucose 6-phosphate (G-6-P) and a decrease in ATP levels and diminished hexokinase binding to mitochondria in single cells. 3-O-methylglucose elicited slowly developing decreases in all three parameters. In contrast, cyanide elicited a rapid decrease in both ATP and hexokinase binding. Analyses of changes in metabolite levels and hexokinase binding indicate a positive correlation between binding and cell energy state as monitored by ATP. On the other hand, only in the presence of 2-deoxyglucose was the predicted inverse correlation between binding and G-6-P observed. Unlike the relatively large changes in distribution observed with the fluorescent-injected hexokinase, cyanide caused only a small decrease in the localization of endogenous hexokinase with mitochondria. These findings suggest that changes in the concentrations of specific metabolites can alter the binding of hexokinase I to specific sites on mitochondria. Moreover, the apparent difference in sensitivity of injected and endogenous hexokinase to changes in metabolites may reflect the presence of at least two classes of binding mechanisms for hexokinase, with differential sensitivity to metabolites.

Abstract 238: ABCA1 and HDL3 are Required to Modulate Smooth Muscle Cells Trandifferentiation in a Myocardin-miR143/145-dependent Process

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Silvia Castiglioni ◽  
Alessio Vettore ◽  
Lorenzo Arnaboldi ◽  
Laura Calabresi ◽  
Alberto Corsini ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cell Types ◽  
Foam Cells ◽  
Knock Out ◽  
Phenotypic Changes ◽  
Basal Expression ◽  
Basal Expression Level

Cells of the artery wall may accumulate free cholesterol and cholesteryl esters becoming foam cells. Up to 50% of foam cells in human lesions originates from smooth muscle cells (SMCs). Arterial SMCs express the ATP binding cassette (ABC) transporter ABCA1 and, upon cholesterol loading, express macrophage markers and a phagocytic activity. To characterize the role of ABCA1 and HDL3 in this transdifferentiation process, we evaluated the phenotypic changes in SMCs isolated from wild type (WT) and ABCA1 knock out (KO) mice and how HDL3 affects these changes. Cholesterol loading causes the downregulation of the expression of SMC markers including ACTA2, alpha-tropomyosin and myosin heavy chain and increases the expression of macrophage-related genes such as CD68, Mac-2, SRB1, MMPs, ABCG1 and ABCA1. HDL3 treatment in WT cells is able to normalize the expression of ACTA2, while the expression of macrophage-related genes is reduced. On the contrary, the preventive effect of HDL3 is completely lost in ABCA1 KO cells. Interestingly, the presence of HDL3 does not differently affect neutral lipid accumulation in WT or ABCA1 KO cells but stimulates phospholipids removal only in WT cells. ApoAI addition does not reverse the phenotypic changes induced by cholesterol not only in KO but also in WT cells. Moreover, cholesterol loading reduces the expression of myocardin, the master SMC specific-transcriptional coactivator involved in SMC differentiation, by up to 55% (p<0.01 vs respective control) in both cell types. HDL3 normalizes myocardin levels in WT cells while it does not have any effect in ABCA1 KO cells. Similar results are obtained evaluating the levels of miR-143/145, which positively regulate myocardin. The basal expression level of KLF4, a myocardin repressor, is almost double in ABCA1 KO cells compared to WT. After cholesterol loading, KLF4 is slightly reduced in WT cells, while its expression is halved in ABCA1 KO cells. HDL3 restores KLF4 to basal levels in KO cells, but it further reduces them in WT cells. These results indicate that HDL3, modulating the miR143/145-myocardin axis in SMC, prevents the cholesterol-induced gene expression modification regardless of its cholesterol unloading capacity and the presence of ABCA1 is required.

The role of globins in cardiovascular physiology

2021 ◽  
Author(s):  
T.C. Steven Keller ◽  
Christophe Lechauve ◽  
Alexander S Keller ◽  
Steven Brooks ◽  
Mitchell J Weiss ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Central Nervous System ◽  
Nervous System ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Cell Types ◽  
Specific Cell ◽  
In Cells

Globin proteins exist in every cell type of the vasculature, from erythrocytes to endothelial cells, vascular smooth muscle cells, and peripheral nerve cells. Many globin subtypes are also expressed in muscle tissues (including cardiac and skeletal muscle), in other organ-specific cell types, and in cells of the central nervous system. The ability of each of these globins to interact with molecular oxygen (O2) and nitric oxide (NO) is preserved across these contexts. Endothelial α-globin is an example of extra-erythrocytic globin expression. Other globins, including myoglobin, cytoglobin, and neuroglobin are observed in other vascular tissues. Myoglobin is observed primarily in skeletal muscle and smooth muscle cells surrounding the aorta or other large arteries. Cytoglobin is found in vascular smooth muscle but can also be expressed in non-vascular cell types, especially in oxidative stress conditions after ischemic insult. Neuroglobin was first observed in neuronal cells, and its expression appears to be restricted mainly to the central and peripheral nervous systems. Brain and central nervous system neurons expressing neuroglobin are positioned close to many arteries within the brain parenchyma and can control smooth muscle contraction and, thus, tissue perfusion and vascular reactivity. Overall, reactions between NO and globin heme-iron contribute to vascular homeostasis by regulating vasodilatory NO signals and scaveging reactive species in cells of the mammalian vascular system. Here, we discuss how globin proteins affect vascular physiology with a focus on NO biology, and offer perspectives for future study of these functions.

Laser-assisted microdissection and real-time PCR detect anti-inflammatory effect of perfluorocarbon

2003 ◽  
Vol 285 (1) ◽  
pp. L55-L62 ◽  
Author(s):  
Katharina von der Hardt ◽  
Michael Andreas Kandler ◽  
Ludger Fink ◽  
Ellen Schoof ◽  
Jörg Dötsch ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Mrna Expression ◽  
Vascular Smooth Muscle Cells ◽  
Alveolar Macrophages ◽  
Real Time Pcr ◽  
Muscle Cells ◽  
Cell Types ◽  
Anti Inflammatory ◽  
Inflammatory Effect

The aim of this study was to identify cell types involved in the anti-inflammatory effect of ventilation with perfluorocarbon in vivo. Fifteen anesthetized, surfactant-depleted piglets received either aerosolized perfluorocarbon (Aerosol-PFC), partial liquid ventilation (rLV) at functional residual capacity (FRC) volume (FRC-PLV), or intermittent mandatory ventilation (control). After laser-assisted microdissection of different lung cell types, mRNA expression of IL-8 and ICAM-1 was determined using TaqMan real-time PCR normalized to hypoxanthine phosphoribosyltransferase (HPRT). IL-8 mRNA expression (means ± SE; control vs. Aerosol-PFC) was 356 ± 142 copies IL-8 mRNA/copy HPRT mRNA vs. 3.5 ± 1.8 in alveolar macrophages ( P <0.01); 208 ± 108 vs. 2.7 ± 0.8 in bronchiolar epithelial cells ( P <0.05); 26 ± 11 vs. 0.7 ± 0.2 in alveolar septum cells ( P <0.01); 2.8 ± 1.0 vs. 0.8 ± 0.4 in bronchiolar smooth muscle cells ( P <0.05); and 1.1 ± 0.4 vs. 0.2 ± 0.05 in vascular smooth muscle cells ( P <0.05). With FRC-PLV, IL-8/HPRT mRNA expression was significantly lower in macrophages, bronchiolar epithelial, and vascular smooth muscle cells. ICAM-1 mRNA expression in vascular endothelial cells remained unchanged. Predominantly, alveolar macrophages and bronchiolar epithelial cells were involved in the inflammatory pulmonary process. The anti-inflammatory effect of Aerosol-PFC was most pronounced.

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