Vascular Smooth Muscle Migration Research Articles

NKX2-5 regulates vessel remodeling in scleroderma-associated pulmonary arterial hypertension.

NKX2-5 is a member of the homeobox-containing transcription factors critical in regulating tissue differentiation in development. Here, we report a role for NKX2-5 in vascular smooth muscle cell phenotypic modulation in vitro and in vascular remodeling in vivo. NKX2-5 is upregulated in scleroderma patients with pulmonary arterial hypertension. Suppression of NKX2-5 expression in smooth muscle cells halted vascular smooth muscle proliferation and migration, enhanced contractility, and blocked the expression of extracellular matrix genes. Conversely, overexpression of NKX2-5 suppressed the expression of contractile genes (ACTA2, TAGLN, CNN1) and enhanced the expression of matrix genes (COL1) in vascular smooth muscle cells. In vivo, conditional deletion of NKX2-5 attenuated blood vessel remodeling and halted the progression to hypertension in a mouse chronic hypoxia model. This study revealed that signals related to injury such as serum and low confluence, which induce NKX2-5 expression in cultured cells, is potentiated by TGF-β and further enhanced by hypoxia. The effect of TGF-β was sensitive to ERK5 and PI3K inhibition. Our data suggest a pivotal role for NKX2-5 in the phenotypic modulation of smooth muscle cells during pathological vascular remodeling and provide proof of concept for therapeutic targeting of NKX2-5 in vasculopathies.

Alternative Methods for the Detection of Superoxide Anion Generation in Platelets.

Reactive oxygen species (ROS) are highly unstable oxygen-containing molecules. Their chemical instability makes them extremely reactive and gives them the ability to react with important biological molecules such as proteins, nucleic acids, and lipids. Superoxide anions are important ROS generated by the reduction of molecular oxygen reduction (i.e., acquisition of one electron). Despite their initial implication exclusively in aging, degenerative, and pathogenic processes, their participation in important physiological responses has recently become apparent. In the vascular system, superoxide anions have been shown to modulate the differentiation and function of vascular smooth muscle cells, the proliferation and migration of vascular endothelial cells in angiogenesis, the immune response, and the activation of platelets in hemostasis. The role of superoxide anions is particularly important in the dysregulation of platelets and the cardiovascular complications associated with a plethora of conditions, including cancer, infection, inflammation, diabetes, and obesity. It has, therefore, become extremely relevant in cardiovascular research to be able to effectively measure the generation of superoxide anions byhuman platelets,understand the redox-dependent mechanisms regulating the balance between hemostasis and thrombosis and, eventually,identify novel pharmacological tools for the modulation of platelet responses leading to thrombosis and cardiovascular complications. This study presents three experimental protocols successfully adopted for the detection of superoxide anions in platelets and the study of the redox-dependent mechanisms regulating hemostasis and thrombosis: 1) dihydroethidium (DHE)-based superoxide anion detection by flow cytometry; 2) DHE-based superoxide anion visualization and analysis by single platelet imaging; and 3) spin probe-based quantification of superoxide anion output in platelets by electron paramagnetic resonance (EPR).

Transcription factor GATA6 promotes migration of human coronary artery smooth muscle cells in vitro.

Vascular smooth muscle cell plasticity plays a pivotal role in the pathophysiology of vascular diseases. Despite compelling evidence demonstrating the importance of transcription factor GATA6 in vascular smooth muscle, the functional role of GATA6 remains poorly understood. The aim of this study was to elucidate the role of GATA6 on cell migration and to gain insight into GATA6-sensitive genes in smooth muscle. We found that overexpression of GATA6 promotes migration of human coronary artery smooth muscle cells in vitro, and that silencing of GATA6 in smooth muscle cells resulted in reduced cellular motility. Furthermore, a complete microarray screen of GATA6-sensitive gene transcription resulted in 739 upregulated and 248 downregulated genes. Pathways enrichment analysis showed involvement of transforming growth factor beta (TGF-β) signaling which was validated by measuring mRNA expression level of several members. Furthermore, master regulators prediction based on microarray data revealed several members of (mitogen activated protein kinase) MAPK pathway as a master regulators, reflecting involvement of MAPK pathway also. Our findings provide further insights into the functional role of GATA6 in vascular smooth muscle and suggest that targeting GATA6 may constitute as a new approach to inhibit vascular smooth muscle migration.

Subclinical Hypertension-Mediated Organ Damage (HMOD) in Hypertension: Atherosclerotic Cardiovascular Disease (ASCVD) and Calcium Score.

Calcium controls numerous events within the vessel wall. Permeability of the endothelium is calcium dependent, as are platelet activation and adhesion, vascular smooth muscle proliferation and migration, and synthesis of fibrous connective tissue. Double-helix computerized tomography is a noninvasive technique that can detect, measure, and compare coronary calcification in the coronary arteries. Despite some convincing evidence about the prognostic value and usefulness of coronary artery calcium score (CACS) in the stratification of cardiovascular risk in the high risk general population and also in hypertensive patients, current guidelines for the management of hypertension, do not include such evaluation among the recommended procedures to be performed in the majority of patients even with the intent to detect hypertension-mediated organ damage (HMOD) in an early phase. On the contrary, the European Society of Cardiology guidelines for the diagnosis and management of chronic coronary syndromes, the 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease, and the 2018 Cholesterol Clinical Practice Guidelines indicate that the evaluation of CACS may be of some usefulness in specific subpopulations, although this view is not accepted in the US Preventive Services Task Force document. Very recently, the European Society of Cardiology Guidelines on cardiovascular disease prevention in clinical practice stated that CACS estimation may be considered to improve risk classification around treatment decision thresholds. In conclusion, the use of CACS as a diagnostic tool is still controversial. While some evidence exists about is ability to improve stratification of cardiovascular risk in primary prevention, in particular in selected patients who are at intermediate or borderline risk of atherosclerotic cardiovascular disease, there is insufficient evidence to use it as a standard means to assess HMOD.

The relationship between phosphodiesterase 4D gene polymorphism and coronary heart disease.

Coronary atherosclerotic heart disease is one of the most common heart diseases that seriously endanger human health. The study found that intracellular second messenger CAMP plays an important role in inhibiting the proliferation and migration of vascular smooth muscle and the local inflammatory response at the damaged vessel. Phosphodiesterase 4D (PDE4D) can specifically degrade cAMP. The purpose of this article is to investigate the relationship between phosphodiesterase 4D gene polymorphism and coronary heart disease and the effect of phosphodiesterase 4D gene polymorphism on cardiovascular, using polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) was used to detect 50 patients with coronary heart disease (ACS group) and 100 patients who were diagnosed with coronary artery disease by coronary angiography at the same time as the control group (NC group). The results of the study showed that the frequencies of AA, AG, and GG genotypes in 150 samples were 25.67%, 54.66%, and 22.67%, respectively, which was consistent with Hard Weber's law (X = 2.186, P = 0.101). The distribution of GG genotype (18% vs. 27%), AA + AG genotype (85% vs. 74%), G (57% vs. 55%), A (43% vs. 45 %) There was no statistically significant difference in allele frequency (P <0.05). From this, it can be seen that the rs918592 polymorphism of the PDE4D gene is not associated with coronary heart disease.

Abstract 12121: Coronary Disease Association With ADAMTS7 is Due to Protease Activity: Implications for Therapeutic Development

Background: Despite contemporary therapy, coronary artery disease (CAD) remains a leading cause of mortality. Genetic variants at ADAMTS7 have been associated with CAD and the loss of ADAMTS7 is protective for atherosclerosis. ADAMTS7 (a disintegrin and metalloproteinase with thrombospondin motifs 7) is a secreted metalloproteinase and complex proteoglycan, yet the mechanism linking ADAMTS7 to CAD risk remains unresolved. Methods and Results: We established a new purification strategy for full-length mouse ADAMTS7 and demonstrated the loss of activity in the catalytic mutant form of ADAMTS7. To test if the enzymatic activity of ADAMTS7 mediates atherosclerosis, we generated a catalytically inactive mutant mouse allele and compared it to the Adamts7 knockout. Using two models of atherosclerosis, we found that reducing either ADAMTS7 dosage or catalytic function decreased the burden of atherosclerosis. We demonstrate impaired vascular smooth muscle migration in both Adamts7 catalytic mutant and null cells using a lateral migration wound healing assay. Expression of the WT allele rescued the migration phenotype in Adamts7 null cells while expression of the catalytic mutant protein did not. We then characterized a human ADAMTS7 coding variant rs3825807 (Ser214Pro) associated with reduced CAD risk. This variant had a hypomorphic effect on ADAMTS7 secretion and migration of vascular smooth muscle cells, findings consistent with our mouse studies. Conclusions: We demonstrated that loss of ADAMTS7 catalytic function protects against atherosclerosis via phenotype switch of VSMCs and that the atherosclerosis protective effects could be mediated by a loss-of-function coding variant associated with CAD risk. In aggregate, we provide compelling evidence that dosage of ADAMTS7 and catalytic function are responsible for the atherosclerotic phenotype, suggesting that the catalytic domain would be an attractive therapeutic target for CAD.

The Role and Molecular Mechanism of P2Y12 Receptors in the Pathogenesis of Atherosclerotic Cardiovascular Diseases

The P2Y receptor family is a class of G protein-coupled receptors activated primarily by adenosine triphosphate (ATP), adenosine diphosphate (ADP), uridine triphosphate (UTP) and uridine diphosphate (UDP). The P2Y12 receptor is expressed on platelets which mediates platelet aggregation and morphological changes. At the same time, during the process of vascular remodeling and atherosclerosis, ADP can also promote the migration and proliferation of vascular smooth muscle and endothelial cells through P2Y12 receptor activating. Furthermore, P2Y12 is involved in many signal transductions processes, such as intimal hyperplasia, monocyte infiltration and so on, which play an important role in immune inflammation and brain injury. In order to solve the diseases induced by P2Y12 receptor, inhibitors such as ticagrelor, clopidogrel were widely used for cardiovascular diseases. However, there were some problems, such as limited antithrombotic effect, remain unsolved. This article summarizes the role and molecular mechanism of P2Y12 receptors in the pathogenesis of cardiovascular-related diseases, providing in-depth expounding on the molecular mechanism of P2Y12 receptor inhibitors and contributing to the treatment of diseases based on P2Y12 receptors.

The Lab4P Consortium of Probiotics Attenuates Atherosclerosis in LDL Receptor Deficient Mice Fed a High Fat Diet and Causes Plaque Stabilization by Inhibiting Inflammation and Several Pro-Atherogenic Processes.

ScopePrevious studies show that Lab4 probiotic consortium plus Lactobacillus plantarum CUL66 (Lab4P) reduces diet‐induced weight gain and plasma cholesterol levels in C57BL/6J mice fed a high fat diet (HFD). The effect of Lab4P on atherosclerosis is not known and is therefore investigated.Methods and ResultsAtherosclerosis‐associated parameters are analyzed in LDL receptor deficient mice fed HFD for 12 weeks alone or supplemented with Lab4P. Lab4P increases plasma HDL and triglyceride levels and decreases LDL/VLDL levels. Lab4P also reduces plaque burden and content of lipids and macrophages, indicative of dampened inflammation, and increases smooth muscle cell content, a marker of plaque stabilization. Atherosclerosis arrays show that Lab4P alters the liver expression of 19 key disease‐associated genes. Lab4P also decreases the frequency of macrophages and T‐cells in the bone marrow. In vitro assays using conditioned media from probiotic bacteria demonstrates attenuation of several atherosclerosis‐associated processes in vitro such as chemokine‐driven monocytic migration, proliferation of monocytes and macrophages, foam cell formation and associated changes in expression of key genes, and proliferation and migration of vascular smooth muscle cells.ConclusionThis study provides new insights into the anti‐atherogenic actions of Lab4P together with the underlying mechanisms and supports further assessments in human trials.

Coronary Disease Association With ADAMTS7 Is Due to Protease Activity.

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Hydrogen sulfide donors: Therapeutic potential in anti-atherosclerosis.

Atherosclerosis (AS), an important cause of high mortality of cardiovascular disease, involves numerous pathophysiological processes, including endothelial cell damage, oxidative stress, inflammation, lipid deposition, vascular smooth muscle proliferation and migration, macrophage-derived foam cell formation, and platelet aggregation, and seriously endangers human health and safe of life. Hydrogen sulfide (H2S) was discovered as the third gaseous signaling molecule following nitric oxide (NO) and carbon monoxide (CO), and has been proposed to exert potentially significant effects in many physiological processes, especially in atherosclerosis. Compelling evidence suggests that malfunction of CSE/H2S pathway and downregulation of endogenous H2S level contribute to the pathogenesis of atherosclerosis, whereas exogenous supplementation of H2S can ameliorate many of atherogenic processes. The current knowledge on the anti-atherogenic role of H2S comes from the use of H2S donors and CSE or CBS inhibitors, or another more accurate genetic technology, including gene knockout and gene therapy studies. Among them H2S releasing donors have vast therapeutic potential in anti-atherosclerosis and are promising as one of the clinical strategies for atherosclerosis treatment. Based on the recent studies on therapeutic effects and mechanisms of H2S donors, this review focuses on the most recent advances of therapeutic potential of H2S donors in anti-atherosclerosis, especially synthetic organic donors, because sulfide salts can release H2S rapidly and lead to various adverse effects. In addition, the future of this domain is prospected.

DNA N6-methyladenine modification in hypertension.

DNA methylation has a role in the pathogenesis of essential hypertension. DNA N6-methyladenine (6mA) modification as a novel adenine methylation exists in human tissues, but whether it plays a role in hypertension development remains unclear. Here, we reported that the global 6mA DNA level in leukocytes was significantly reduced in patients with hypertension and was reversed with successful treatment. Age, systolic blood pressure, and serum total cholesterol and high-density lipoprotein levels were associated with decreased leukocyte 6mA DNA level. Elevated ALKBH1 (AlkB homolog 1), a demethylase of 6mA, level mediated this dynamic change in 6mA level in leukocytes and vascular smooth muscle cells in hypertension mouse and rat models. Knockdown of ALKBH1 suppressed angiotensin II-induced vascular smooth muscle phenotype transformation, proliferation and migration. ALKBH1-6mA directly and negatively regulated hypoxia inducible factor 1 α (HIF1α), which responded to angiotensin II-induced vascular remodeling. Collectively, our results demonstrate a potential epigenetic role for ALKBH1-6mA regulation in hypertension development, diagnosis and treatment.

Curcumin inhibits proliferation, migration and neointimal formation of vascular smooth muscle via activating miR-22

Context Curcumin has antitumor, antioxidative, anti-inflammatory, and anti-proliferative properties. Objective To investigate the role of miR-22 during curcumin-induced changes in vascular smooth muscle cells (VSMC) and neointima formation in balloon-injured rat abdominal aorta. Materials and methods Sprague-Dawley rats were randomised to the sham-operated (n = 10), operated control (injured, n = 10), and curcumin treatment (n = 10) groups. miR-22 expression was determined by real-time PCR. SP1 was assessed by western blot and real-time PCR. Rat aortic smooth muscle A7r5 cells were used to determine VSMC proliferation and migration, which were measured by the MTS, EdU staining, Transwell, and wound healing assays. Results miR-22 levels declined following arterial balloon injury in vivo (48% at 3d, p < 0.05) and serum stimulation in vitro (45% at 24 h, p < 0.01). Functional studies revealed that miR-22 negatively regulated the proliferation and migration of VSMCs by directly targeting the SP1 transcription factor in VSMCs. Curcumin increased the expression of miR-22 (81%, p < 0.05) and decreased the protein expression of SP1 in VSMCs (25%, p < 0.05). miR-22 inhibition was found to attenuate the effects of curcumin on VSMC functions. Curcumin increased miR-22 (46%, p < 0.01), decreased the SP1 protein (19%, p < 0.05), and inhibited vascular neointimal area (48%, p < 0.01) in vivo. Discussion The miR-22/SP1 pathway is involved in the protective role of curcumin during arterial balloon injury, but the mechanisms remain unclear. Conclusion miR-22 is involved in the inhibitory effects of curcumin on VSMCs’ proliferation, migration and neointima hyperplasia after arterial balloon injury in rats. Curcumin could be used to prevent neointimal hyperplasia after angioplasty.

Long non‑coding RNA MALAT1 sponges miR‑124‑3p.1/KLF5 to promote pulmonary vascular remodeling and cell cycle progression of pulmonary artery hypertension.

Previous studies have demonstrated that long non-coding RNA (lncRNA) is involved in vascular remodeling. The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) lncRNA is associated with the proliferation and migration of vascular smooth muscle and endothelial cells; however, its biological role in pulmonary artery hypertension (PAH) is currently unclear. The aim of the present study was to investigate the post-transcriptional regulation of MALAT1 in human pulmonary artery smooth muscle cells (HPASMCs). The results revealed that MALAT1 expression levels were significantly upregulated in the pulmonary arteries (PAs) and HPASMCs obtained from patients with PAH compared with adjacent normal PA tissues and HPASMCs. Knockdown of MALAT1 suppressed the viability and proliferation of HPASMCs and prevented cells entering the G0/G1 cell cycle phase. MALAT1 overexpression exerted the opposite effects. Bioinformatics analysis predicted complementary binding of hsa-microRNA (miR)-124-3p.1 with the 3′-untranslated region of MALAT1. Luciferase reporter assays and RNA immunoprecipitation experiments demonstrated molecular binding between MALAT1 and hsa-miR-124-3p.1. This resulted in the formation of an RNA-induced silencing complex. In addition, Kruppel-like factor 5 (KLF5) was confirmed to be a target gene of MALAT1/hsa-miR-124-3p.1. MALAT1 silencing did not inhibit the proliferation and migration of HPASMCs following knockdown of hsa-miR-124-3p.1. In addition, MALAT1 knockdown was demonstrated to attenuate the expression of KLF5. Following MALAT1 knockdown, the expression level of KLF5 was rescued by inhibition of hsa-miR-124-3p.1 expression. The results of the current study indicate that the MALAT1/hsa-miR-124-3p.1/KLF5 axis may serve a key role in HPASMCs. In addition, the results contribute to what is known regarding the role of MALAT1 in PAH development and provide a novel theoretical basis for the development of new therapeutic interventions for patients with PAH.

Circular RNA circCHFR Facilitates the Proliferation and Migration of Vascular Smooth Muscle via miR-370/FOXO1/Cyclin D1 Pathway

Circular RNA (circRNA) is a novel subgroup of noncoding RNA in the human transcriptome playing a vital role in the atherosclerosis of cerebrovascular disease. However, the in-depth mechanism by which circRNA regulates the vascular smooth muscle proliferation and migration is still elusive. Here, a novel identified circRNA, circCHFR, was validated to be aberrantly overexpressed in the ox-LDL-induced vascular smooth muscle cell (VSMCs). Functionally, the circCHFR silencing by oligonucleotide transfection suppressed the proliferation and migration ability of VSMCs. Mechanically, bioinformatics tools and luciferase reporter assay state that circCHFR acts as a sponge of miR-370, and miR-370 targets the 3′ UTR of FOXO1. Furthermore, the transcription factor FOXO1 could bind with the promoter region of CCND1 mRNA and promote Cyclin D1 expression. In summary, this finding states the vital role of the circCHFR/miR-370/FOXO1/Cyclin D1 axis and provides a profound understanding about the circRNA in smooth muscle cells and atherosclerosis.

Haem oxygenase-1 inhibits neointimal hyperplasia in rat by histone deacetylase 2

It has been reported that haem oxygenase-1 (Hmox1) induction attenuates neointimal thickening. Here we further investigated the potential mechanisms regulating this important pathological process. We revealed that histone deacetylase 2 (HDAC2) was induced following Hmox1 induction under 1% oxygen treatment and this induction was attenuated after the treatment of siRNA against Hmox1. Interestingly, this HDAC2 induction was dependent on Hmox1 protein as well as its enzymatic activity, and was regulated by carbon monoxide released from haem degradation. Furthermore, histone deacetylase inhibitor, trichostatin A, successfully abrogated the inhibitory effects of vascular smooth muscle migration and proliferation by Hmox1 induction in vitro. In a rat carotid balloon injury model, similar results were observed by measuring neointimal thickening. As such, we concluded that Hmox1 inhibits neointimal hyperplasia via HDAC2 in rats.

A role of coagulation factor XI as a regulator of vascular smooth muscle migration

A role of coagulation factor XI as a regulator of vascular smooth muscle migration

Role of mimecan in development of atherosclerosis induced by increased blood pressure variability

To examine the changes of mimecan protein expression in development of atherosclerosis induced by sinoaortic denervation, and to explore the effects of mimecan knock down on the proliferation and migration of vascular smooth muscle cells. Methods: The animals were randomly divided into a sham group and a model group (n=8 in each group). The rat model of blood pressure variability was established by sinoaortic denervation, and the hemodynamic indexes were recorded 20 weeks after the surgery to confirm the success of the model. The thoracic aorta was excised and stained with immunohistochemistry to observe the pathological changes of smooth muscle tissues and the changes of mimecan expression. The mice vascular smooth muscle cells were isolated, and which were treated with mimecan siRNA to knock down the mimecan expression. The cell proliferation was observed by 5-ethynyl-2'-deoxyuridine (Edu) in corporation test and the changes of cell migration was observed by wound healing test. Results: Twenty weeks after sinoaortic denervation, the blood pressure variability in the model group was significantly increased compared with that in the sham group, suggesting the model was successfully established. In addition, the increased blood pressure variability in the model group promoted the proliferation and migration of the vascular smooth muscle cells in thoracic aorta, while the expression of mimecan protein was significantly decreased. In in vitro assays, the knock down of mimecan in mice vascular smooth muscle cells could promote the cell proliferation and migration. Conclusion: Mimecan plays a protective role in the development of sinoaortic denervation induced atherosclerosis through amechanism involving suppression of the proliferation and migration of vascular smooth muscle cells.

S100B promotes injury-induced vascular remodeling through modulating smooth muscle phenotype

S100B is a biomarker of nervous system injury, but it is unknown if it is also involved in vascular injury. In the present study, we investigated S100B function in vascular remodeling following injury. Balloon injury in rat carotid artery progressively induced neointima formation while increasing S100B expression in both neointimal vascular smooth muscle (VSMC) and serum along with an induction of proliferating cell nuclear antigen (PCNA). Knockdown of S100B by its shRNA delivered by adenoviral transduction attenuated the PCNA expression and neointimal hyperplasia in vivo and suppressed PDGF-BB-induced VSMC proliferation and migration in vitro. Conversely, overexpression of S100B promoted VSMC proliferation and migration. Mechanistically, S100B altered VSMC phenotype by decreasing the contractile protein expression, which appeared to be mediated by NF-κB activity. S100B induced NF-κB-p65 gene transcription, protein expression and nuclear translocation. Blockade of NF-κB activity by its inhibitor reversed S100B-mediated downregulation of VSMC contractile protein and increase in VSMC proliferation and migration. It appeared that S100B regulated NF-κB expression through, at least partially, the Receptor for Advanced Glycation End products (RAGE) because RAGE inhibitor attenuated S100B-mediated NF-κB promoter activity as well as VSMC proliferation. Most importantly, S100B secreted from VSMC impaired endothelial tube formation in vitro, and knockdown of S100B promoted re-endothelialization of injury-denuded arteries in vivo. These data indicated that S100B is a novel regulator for vascular remodeling following injury and may serve as a potential biomarker for vascular damage or drug target for treating proliferative vascular diseases.

Purinergic Signaling in the Cardiovascular System.

There is nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory-motor nerves, as well as in intracardiac neurons. Centers in the brain control heart activities and vagal cardiovascular reflexes involve purines. Adenine nucleotides and nucleosides act on purinoceptors on cardiomyocytes, AV and SA nodes, cardiac fibroblasts, and coronary blood vessels. Vascular tone is controlled by a dual mechanism. ATP, released from perivascular sympathetic nerves, causes vasoconstriction largely via P2X1 receptors. Endothelial cells release ATP in response to changes in blood flow (via shear stress) or hypoxia, to act on P2 receptors on endothelial cells to produce nitric oxide, endothelium-derived hyperpolarizing factor, or prostaglandins to cause vasodilation. ATP is also released from sensory-motor nerves during antidromic reflex activity, to produce relaxation of some blood vessels. Purinergic signaling is involved in the physiology of erythrocytes, platelets, and leukocytes. ATP is released from erythrocytes and platelets, and purinoceptors and ectonucleotidases are expressed by these cells. P1, P2Y1, P2Y12, and P2X1 receptors are expressed on platelets, which mediate platelet aggregation and shape change. Long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides promote migration and proliferation of vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis, vessel remodeling during restenosis after angioplasty and atherosclerosis. The involvement of purinergic signaling in cardiovascular pathophysiology and its therapeutic potential are discussed, including heart failure, infarction, arrhythmias, syncope, cardiomyopathy, angina, heart transplantation and coronary bypass grafts, coronary artery disease, diabetic cardiomyopathy, hypertension, ischemia, thrombosis, diabetes mellitus, and migraine.

Ca2+/Calmodulin-Dependent Protein Kinase II in Vascular Smooth Muscle.

Ca2+-dependent signaling pathways are central regulators of differentiated vascular smooth muscle (VSM) contractile function. In addition, Ca2+ signals regulate VSM gene transcription, proliferation, and migration of dedifferentiated or "synthetic" phenotype VSM cells. Synthetic phenotype VSM growth and hyperplasia are hallmarks of pervasive vascular diseases including hypertension, atherosclerosis, postangioplasty/in-stent restenosis, and vein graft failure. The serine/threonine protein kinase Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a ubiquitous mediator of intracellular Ca2+ signals. Its multifunctional nature, structural complexity, diversity of isoforms, and splice variants all characterize this protein kinase and make study of its activity and function challenging. The kinase has unique autoregulatory mechanisms, and emerging studies suggest that it can function to integrate Ca2+ and reactive oxygen/nitrogen species signaling. Differentiated VSM expresses primarily CaMKIIγ and -δ isoforms. CaMKIIγ isoform expression correlates closely with the differentiated phenotype, and some studies link its function to regulation of contractile activity and Ca2+ homeostasis. Conversely, synthetic phenotype VSM cells primarily express CaMKIIδ and substantial evidence links it to regulation of gene transcription, proliferation, and migration of VSM in vitro, and vascular hypertrophic and hyperplastic remodeling in vivo. CaMKIIδ and -γ isoforms have opposing functions at the level of cell cycle regulation, proliferation, and VSM hyperplasia in vivo. Isoform switching following vascular injury is a key step in promoting vascular remodeling. Recent availability of genetically engineered mice with smooth muscle deletion of specific isoforms and transgenics expressing an endogenous inhibitor protein (CAMK2N) has enabled a better understanding of CaMKII function in VSM and should facilitate future studies.