apyrase and Atherosclerosis

Diabetes is an important risk factor for the development of cardiovascular disease including atherosclerosis and ischemic heart disease. Vascular complications including macro- and micro-vascular dysfunction are the leading causes of morbidity and mortality in diabetes. Disease mechanisms at present are unclear and no ideal therapies are available, which urgently calls for the identification of novel therapeutic targets/agents. An altered nucleotide- and nucleoside-mediated purinergic signaling has been implicated to cause diabetes-associated vascular dysfunction in major organs. Alteration of both purinergic P1 and P2 receptor sensitivity rather than the changes in receptor expression accounts for vascular dysfunction in diabetes. Activation of P2X

Topics: 5'-Nucleotidase; Adenosine Triphosphate; Animals; Apyrase; Atherosclerosis; Diabetes Mellitus; Diabetic Angiopathies; Erythrocytes; GPI-Linked Proteins; Humans; Receptors, Purinergic P1; Receptors, Purinergic P2X7; Retinal Vessels; Signal Transduction

Extracellular nucleotides play a critical role in vascular thrombosis and inflammation. Alterations in purinergic extracellular nucleotide concentrations activate pathways that result in platelet degranulation and aggregation, and endothelial and leukocyte activation and recruitment. CD39, the dominant vascular nucleotidase, hydrolyzes ATP and ADP to provide the substrate for generation of the anti-inflammatory and antithrombotic mediator adenosine. The purinergic signaling system, with CD39 at its center, plays an important role in modulating vascular homeostasis and the response to vascular injury, as seen in clinically relevant diseases such as stroke, ischemia-reperfusion injury, and pulmonary hypertension. A growing body of knowledge of the purinergic signaling pathway implicates CD39 as a critical modulator of vascular thrombosis and inflammation. Therapeutic strategies targeting CD39 offer promising opportunities in the management of vascular thromboinflammatory diseases.

Topics: Antigens, CD; Apyrase; Atherosclerosis; Endothelium, Vascular; Humans; Hypertension, Pulmonary; Inflammation; Myocardial Ischemia; Myocardial Reperfusion Injury; Signal Transduction; Stroke; Thrombosis; Vasculitis

Extracellular nucleotides and nucleosides act as signaling molecules involved in a wide spectrum of biological effects. Their levels are controlled by a complex cell surface-located group of enzymes called ectonucleotidases. There are four major families of ectonucleotidases, nucleoside triphosphate diphosphohydrolases (NTPDases/CD39), ectonucleotide pyrophosphatase/phosphodiesterases (E-NPPs), alkaline phosphatases and ecto-5'-nucleotidase. In the last few years, substantial progress has been made toward the molecular identification of members of the ectonucleotidase families and their enzyme structures and functions. In this review, there is an emphasis on the involvement of NTPDase and 5'-nucleotidase activities in disease processes in several tissues and cell types. Brief background information is given about the general characteristics of these enzymes, followed by a discussion of their roles in thromboregulatory events in diabetes, hypertension, hypercholesterolemia and cancer, as well as in pathological conditions where platelets are less responsive, such as in chronic renal failure. In addition, immunomodulation and cell-cell interactions involving these enzymes are considered, as well as ATP and ADP hydrolysis under different clinical conditions related with alterations in the immune system, such as acute lymphoblastic leukemia (ALL), B-chronic lymphocytic leukemia (B-CLL) and infections associated with human immunodeficiency virus (HIV). Finally, changes in ATP, ADP and AMP hydrolysis induced by inborn errors of metabolism, seizures and epilepsy are discussed in order to highlight the importance of these enzymes in the control of neuronal activity in pathological conditions. Despite advances made toward understanding the molecular structure of ectonucleotidases, much more investigation will be necessary to entirely grasp their role in physiological and pathological conditions.

Topics: 5'-Nucleotidase; Adenosine; Adenosine Triphosphate; Animals; Antigens, CD; Apyrase; Atherosclerosis; Blood Coagulation; Blood Platelets; Cell Communication; Demyelinating Diseases; Epilepsy; Humans; Metabolism, Inborn Errors; Myocardial Infarction; Neoplasms; Platelet Activation; Platelet Aggregation; Seizures; Signal Transduction; Tamoxifen; Thrombosis

CD8. We compared the cytokine production of CD8. Our results suggest that the continuous TCR signaling in the atherosclerotic environment in the vessel wall induces an immune regulatory CD8

Topics: Animals; Antigens, CD; Apyrase; Atherosclerosis; CD8-Positive T-Lymphocytes; Cells, Cultured; Cellular Microenvironment; Humans; Inflammation; Male; Mice; Mice, Inbred C57BL; Receptors, Antigen, T-Cell; Signal Transduction

A common thread underlying vascular or tissue injury is the loss of plasmalemmal integrity and the passive (or even active) spillage of intracellular contents into the circulation. Purinergic nucleotides, which serve as energy shuttling moieties within cells, are among the contents released into the bloodstream, where they signal danger and trigger thrombosis and inflammation. To regain vascular homeostasis, vascular cells have evolved highly conserved mechanisms to transact the catalytic degradation of extracellular nucleotides such as adenosine triphosphate (ATP) and adenosine diphosphate (ADP). CD39, the main endothelial ectonucleotidase which cleaves ATP and ADP, plays an essential role in ridding the bloodstream of these danger signals, thereby sustaining vascular homeostasis. Studies herein describe the upregulation of endothelial CD39 gene by steady laminar shear forces, and conversely, its downregulation under turbulent flow conditions. CD39 appears to be a critical ectonucleotidase which suppresses atherogenesis under experimental hyperlipidemic conditions in mice, and which also significantly mitigates pathologic vascular remodeling and development of pulmonary arterial hypertension in mice placed under chronic hypoxic conditions. Together, these data reveal that CD39 opposes pathologic vascular remodeling under hyperlipidemic or hypoxic conditions. CD39 can therefore be viewed as a critical vascular homeostatic regulator to sustain vascular quiescence and to protect against pathological vascular remodeling in diseases as diverse as atherosclerosis and pulmonary arterial hypertension.

Topics: Animals; Apyrase; Atherosclerosis; Cell Proliferation; Cells, Cultured; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Humans; Hypertension, Pulmonary; Mechanotransduction, Cellular; Plaque, Atherosclerotic; Pulmonary Artery; Regional Blood Flow; Signal Transduction; Vascular Remodeling

Purinergic signaling plays an important role in inflammation and vascular integrity, but little is known about purinergic mechanisms during the pathogenesis of atherosclerosis in humans.. The objective of this study is to study markers of purinergic signaling in a cohort of patients with peripheral artery disease.. Plasma ATP and ADP levels and serum nucleoside triphosphate diphosphohydrolase-1 (NTPDase1/CD39) and ecto-5'-nucleotidase/CD73 activities were measured in 226 patients with stable peripheral artery disease admitted for nonurgent invasive imaging and treatment. The major findings were that ATP, ADP, and CD73 values were higher in atherosclerotic patients than in controls without clinically evident peripheral artery disease (P<0.0001). Low CD39 activity was associated with disease progression (P=0.01). In multivariable linear regression models, high CD73 activity was associated with chronic hypoxia (P=0.001). Statin use was associated with lower ADP (P=0.041) and tended to associate with higher CD73 (P=0.054), while lower ATP was associated with the use of angiotensin receptor blockers (P=0.015).. Purinergic signaling plays an important role in peripheral artery disease progression. Elevated levels of circulating ATP and ADP are especially associated with atherosclerotic diseases of younger age and smoking. The antithrombotic and anti-inflammatory effects of statins may partly be explained by their ability to lower ADP. We suggest that the prothrombotic nature of smoking could be a cause of elevated ADP, and this may explain why cardiovascular patients who smoke benefit from platelet P2Y12 receptor antagonists more than their nonsmoking peers.

Topics: 5'-Nucleotidase; Adenosine Diphosphate; Adenosine Triphosphate; Adult; Age Factors; Aged; Aged, 80 and over; Alkaline Phosphatase; Angiotensin-Converting Enzyme Inhibitors; Antigens, CD; Apyrase; Artifacts; Atherosclerosis; Biomarkers; Chronic Disease; Comorbidity; Disease Progression; Drug Utilization; Female; Finland; GPI-Linked Proteins; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypertension; Hypoxia; Male; Middle Aged; Models, Cardiovascular; Peripheral Arterial Disease; Purinergic P2Y Receptor Antagonists; Risk Factors; Second Messenger Systems; Smoking; Thrombophilia

The ability of cells to detect and respond to nucleotide signals in the local microenvironment is essential for vascular homeostasis. The enzyme ectonucleotide tri(di)phosphohydrolase-1 (ENTPD1, also known as CD39) on the surface of leukocytes and endothelial cells metabolizes locally released, intravascular ATP and ADP, thereby eliminating these prothrombotic and proinflammatory stimuli. Here, we evaluated the contribution of CD39 to atherogenesis in the apolipoprotein E-deficient (ApoE-deficient) mouse model of atherosclerosis. Compared with control ApoE-deficient animals, plaque burden was markedly increased along with circulating markers of platelet activation in Cd39+/-Apoe-/- mice fed a high-fat diet. Plaque analysis revealed stark regionalization of endothelial CD39 expression and function in Apoe-/- mice, with CD39 prominently expressed in atheroprotective, stable flow regions and diminished in atheroprone areas subject to disturbed flow. In mice, disturbed flow as the result of partial carotid artery ligation rapidly suppressed endothelial CD39 expression. Moreover, unidirectional laminar shear stress induced atheroprotective CD39 expression in human endothelial cells. CD39 induction was dependent upon the vascular transcription factor Krüppel-like factor 2 (KLF2) binding near the transcriptional start site of CD39. Together, these data establish CD39 as a regionalized regulator of atherogenesis that is driven by shear stress.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Antigens, CD; Apolipoproteins E; Apyrase; Atherosclerosis; Blood Flow Velocity; Blood Platelets; Dietary Fats; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Human Umbilical Vein Endothelial Cells; Humans; Kruppel-Like Transcription Factors; Mice; Mice, Knockout; Plaque, Atherosclerotic; Platelet Activation; Response Elements; Shear Strength

Stent angioplasty provides a minimally invasive treatment for atherosclerotic vessels. However, no treatment option for atherosclerosis-associated endothelial dysfunction, which is accompanied by a loss of CD39, is available, and hence, adverse effects like thromboembolism and restenosis may occur. Messenger RNA (mRNA)-based therapy represents a novel strategy, whereby de novo synthesis of a desired protein is achieved after delivery of a modified mRNA to the target cells.. Our study aimed to develop an innovative bioactive stent coating that induces overexpression of CD39 in the atherosclerotic vessel. Therefore, a modified CD39-encoding mRNA was produced by in vitro transcription. Different endothelial cells (ECs) were transfected with the mRNA, and CD39 expression and functionality were analyzed using various assays. Furthermore, CD39 mRNA was immobilized using poly(lactic-co-glycolic-acid) (PLGA), and the transfection efficiency in ECs was analyzed. Our data show that ECs successfully translate in vitro-generated CD39 mRNA after transfection. The overexpressed CD39 protein is highly functional in hydrolyzing ADP and in preventing platelet activation. Furthermore, PLGA-immobilized CD39 mRNA can be delivered to ECs without losing its functionality.. In summary, we present a novel and promising concept for a stent coating for the treatment of atherosclerotic blood vessels, whereby patients could be protected against angioplasty-associated complications.

Topics: Angioplasty; Animals; Antigens, CD; Apyrase; Atherosclerosis; Cell Line; Endothelial Cells; HEK293 Cells; Humans; RNA, Messenger; Stents; Swine

Topics: 5'-Nucleotidase; Adenosine; Adenosine Monophosphate; Adenosine Triphosphate; Antigens, CD; Apyrase; Atherosclerosis; Calcinosis; Fibroblasts; Gene Deletion; Humans; Hydrolysis; Mutation; Phosphoric Diester Hydrolases; Pyrophosphatases

Both platelet aggregation and high blood pressure are associated with development of atherosclerosis. Among other factors that modulate platelet aggregation and blood pressure, extracellular purines (e-purines) influence these processes via purinoceptors P1 and P2 for which they are natural ligands. We hypothesized that ecto-enzymes such as nucleoside triphosphate diphosphohydrolases (NTPDases), adenylate kinase, 5'-nucleotidase, and adenosine deaminase that regulate the level of e-purines may be involved in the development of atherosclerosis. The enzymatic assays were performed either on the fragments of human abdominal aortas obtained after death or on abdominal aneurysm samples collected during surgery. The substrates and products such as adenine nucleosides and nucleotides were analyzed using reverse phase high-performance liquid chromatography (HPLC) method. Here, we estimated and demonstrated the activities of these ecto-enzymes in the patients with atherosclerosis or atherosclerosis-like diseases such as abdominal aneurysm, myocardial infarction, or Leriche syndrome (LS) with worse thrombosis of extremities. In particular, we noticed reduction in activity of NTPDase1(app), NTPDase2(app), ecto-adenylate kinase( app), and ecto-adenosine deaminase(app); however, ecto-5'-nucleotidase(app) that hydrolyzed e-adenosine monophosphate (e-AMP) into e-adenosine did not show any significant changes. This led us to suggest that alteration of the activity of examined ecto-enzymes is responsible for the development of atherosclerosis or atherosclerosis-like diseases.

Topics: 5'-Nucleotidase; Adenosine Deaminase; Adenosine Triphosphatases; Adenylate Kinase; Antigens, CD; Aortic Aneurysm, Abdominal; Apyrase; Atherosclerosis; Blood Vessels; Cell Survival; Endothelial Cells; Extracellular Space; Humans; Leriche Syndrome; Purines