Current Vascular Pharmacology - Volume 15, Issue 3, 2017

Cardiovascular (CV) diseases remain a leading cause of morbidity and mortality in the world. Increasing the understanding of the pathogenesis of various CV diseases may provide novel therapeutic targets to improve their prevention and treatment. Cartilage oligomeric matrix protein (COMP), also known as thrombospondin-5 (TSP-5), is a matricellular protein that is abundantly expressed in both cartilage and the CV system. Our group and others have identified COMP as playing critical roles in maintaining CV homeostasis. COMP, expressed and produced by vascular smooth muscle cells (VSMCs), maintains VSMC contractile phenotypes. COMP deficiency enhances VSMC migration and aggravates VSMC calcification and atherosclerosis. Moreover, a lack of COMP leads to spontaneous dilated cardiomyopathy in mice. COMP is also secreted by platelets in circulating blood and negatively regulates haemostasis and thrombosis. A series of COMP binding proteins, such as integrin α7β1, integrin β3, thrombin, and bone morphogenetic protein 2, have been identified in the CV system, and they have been determined to mediate various COMP functions. The matrix metalloproteinase (A Disintegrin and Metalloproteinase with Thrombospondin motifs) ADAMTS-7 is a regulatory enzyme that is responsible for the degradation of COMP in the CV system. ADAMTS-7 expression correlates with atherosclerosis and vascular calcification in both human genome-wide association studies and in vivo mice models via COMP-dependent and COMP-independent mechanisms. In this review, we summarize what is currently known about the matricellular and matricrine signaling of COMP mediated by its respective binding partners as well as its proteolytic regulation by ADAMTS-7 in CV disease.

Pregnancy-Associated Plasma Protein-A (PAPP-A) is a zinc-binding metalloproteinase protein produced by placental syncytio-trophoblasts and secreted into the maternal circulation where its concentration progressively increases until term. In recent years, PAPP-A has been studied for its potential involvement in cardiovascular (CV) disease. However, all those studies did not provide a clear view to identify the pathophysiological links between PAPP-A plasma levels and the occurrence of CV events. In this review, starting from a complete description of PAPP-A structure and biology, we present an updated overview of experimental as well as clinical evidence on the role of this metalloproteinase in CV disease. Finally, we discuss possible therapeutic approaches to antagonize its potential detrimental CV effects.

The association between type 2 diabetes mellitus (T2DM) and systemic inflammation may increase platelet reactivity and the accelerated development of vascular disease. Platelets are able to modulate the function of immune cells via the direct release of growth factors and pro-inflammatory chemokines through the production of microvesicles. The microvesicles trigger a transcellular delivery system of bioactive molecules to other cells acting as vectors in the exchange of biological information. Here, we consider the influence of platelets and platelet-derived microvesicles on cells of the immune system and the implications in the pathogenesis of T2DM.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in females and is often associated with a number of cardiometabolic disorders such as central obesity, dyslipidaemia, hypertension, insulin resistance, hyperinsulinaemia, glucose intolerance and type 2 diabetes mellitus (T2DM). Glucagon-like peptide-1 (GLP-1), a gut hormone secreted after a meal, enhances glucosestimulated insulin secretion and additionally suppresses appetite and gastric motility. Most studies found impaired GLP-1 kinetics in obese individuals, whereas small studies in PCOS reported reduced, normal or even elevated GLP-1 levels. Apart from their efficacy in patients with T2DM, some GLP-1 receptor agonists (GLP-1 RAs) have been successfully tested in terms of both efficiency and safety in obese individuals without diabetes and liraglutide 3 mg once daily has been approved as an antiobesity drug in the USA and the European Union. Recently, some small trials of short duration using GLP-1 RAs as monotherapy or combined with metformin in obese PCOS women showed positive results regarding weight reduction and a decrease in testosterone levels but without significant effects on insulin levels, insulin sensitivity and menstrual patterns. Longer term studies with more patients and higher doses of liraglutide (as this drug is already approved for obese individuals) are required to determine the precise indications of GLP-1 RAs in PCOS and to evaluate safety issues.

Endovascular surgery represents a minimally invasive procedure for the treatment of occlusive and aneurysmal arterial disease. However, it is followed by inflammatory response, with a rise in specific inflammatory biomarkers, such as C-reactive protein, serum amyloid A and fibrinogen. Shear stress during balloon inflation and vascular injury represents triggering events for the inflammatory process, stimulating the production of proinflammatory molecules and activation of circulating monocytes. The current literature indicates that stent implantation induces more prominent inflammatory reaction. Additionally, it has been shown that muscular arteries of femoropopliteal segment react to a greater extent to stent implantation, compared with elastic carotid or iliac arteries. The endovascular treatment of thoracic and abdominal aortic aneurysm is frequently followed with post-implantation inflammatory syndrome. Most recent findings point out that stent graft material plays a significant role in the inflammatory response, representing a challenge for clinicians. Future studies should consider the pathophysiology of the inflammatory response associated with endovascular procedures as well as predictors and risk factors including preventive strategies and therapeutic algorithms. Although the potential role of anti-inflammatory drugs after endovascular procedures has been observed, it needs to be validated in upcoming trials. The Neutrophil Lymphocyte Ratio, platelet count, Platelet-to-Lymphocyte Ratio and other biomarkers should be considered in future trials to assess the inflammatory response after endovascular procedures. Inflammatory markers may also become therapeutic targets.

The beneficial effects of chronic exercise training on lipoprotein metabolism include a considerable increase in serum high density lipoprotein-cholesterol and a reduction in serum triglyceride levels. These changes are mostly reported in athletes participating in dynamic sports, especially in the endurance ones. Diagnosis and treatment of dyslipidaemias in athletes should follow the main principles of management of dyslipidaemias for the general population, while specific considerations for athletes should be taken into account. Dyslipidaemias in athletes are usually characterized by a significant genetic predisposition. Clinicians who evaluate the lipoprotein profile of athletes should keep in mind the possibility of an illegal use of performance-enhancing drugs, which can influence lipoprotein metabolism. Lifestyle intervention should be the cornerstone of treatment of dyslipidaemias in athletes, but it should be tailored to the needs of individual athletic activity. Hypolipidaemic medications may not be well-tolerated by competitive athletes and should be reserved only for athletes with inadequate response to lifestyle measures. The treatment of dyslipidaemias in athletes should aim at reducing cardiovascular risk without compromising athletic performance.

Background: Cardiovascular risk (CV) factors associated with the metabolic syndrome (MetS) may vary in different populations. In some, hypertension may be the major determinant, in others are low high-density lipoprotein cholesterol (HDL-C), high triglycerides, or another component. Subjects and Methods: Subjects included in this analysis were identified in 2006, among those attending the Lipid Clinic of the Niguarda Hospital, and followed up through to 2013. Patient characteristics (including the occurrence of CV events) were obtained from electronic medical records. MetS was diagnosed according to the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) guidelines. The carotid intima media thickness (cIMT) was also followed in these patients over the years. Results: After 7 years a total of 858 subjects had a complete follow-up; 271 of those had MetS. Patients developing a CV event showed elevated baseline cIMT (e.g. cIMTmax ≥2.4 mm in males and ≥2.2 mm in females); moreover the cIMT in MetS patients was higher at baseline and the rise over 7 years was larger compared with patients without MetS. By examining each body variable for MetS we found that a waist to height ratio (WHtR) ≥0.5 was present in nearly all subjects with a CV event. Conclusion: The follow-up data of a series of Italian patients with and without MetS, clearly indicates that the former have a raised cIMT and their arterial IMT progression is greater and the presence of a larger WHtR is apparently linked to a higher incidence of CV events.

Background: Drug-eluting stents (DES) are now considered the most promising device to treat peripheral artery disease (PAD) and minimize restenosis. There is uncertainty however on the best antirestenotic drug for such devices. In particular, biolimus (i.e. umirolimus) and everolimus are two of the most promising agents, given the extensive data in support of their coronary safety and efficacy, but their comparative effectiveness for peripheral interventions is not established. Methods: Building upon our extensive experience in the percutaneous treatment of infra-inguinal artery disease with DES, we compared the acute and longterm outlook of patients treated with biolimus-eluting stents (BES) and everolimus-eluting stents (EES). We collected baseline, procedural and outcome details on all patients undergoing infra-inguinal BES or EES implantation. The endpoints of interest were death, amputation, revascularization, their composite, and change in Fontaine class. A total of 80 patients were included (20 treated with BES and 60 with EES). Most features were similar in the two groups, despite longer lesions in the EES group. Unadjusted analysis showed similar results irrespective of the drug used, with composite endpoint occurring, respectively, in 4 (20.0%) and 10 (16.7%) (p=0.741). Results and Conclusion: However, analysis with inverse probability of treatment weighting showed significant differences in the risk of revascularization (hazard ratio of BES vs EES=9.55 [95% confidence interval 2.16-42.23], p=0.003) and composite endpoint (hazard ratio=5.11 [1.33-19.62], p=0.018). In conclusion, EES appear superior to BES for endovascular therapy of infrainguinal artery disease. Dedicated randomized trials are required to definitely confirm or disprove these findings.

Background: Chronic ethanol (EtOH) consumption has been associated with deleterious effects on the cardiovascular system by abnormal calcium (Ca2+) handling. Store-operated Ca2+ entry (SOCE) is related to cardiovascular remodeling which leads to the hypertension development, and the coupling between STIM-1 (ER Ca2+ sensor) and Orai-1 (channel pore) is a key mechanism to control SOCE through of store-operated Ca2+ channels (SOCCs). However, the role of STIM-1/Orai-1-mediated SOCE and its cross-talk with EtOH-triggered vascular remodeling and hypertension remain poorly understood. We address this subject in the present study by evaluating how chronic EtOH consumption induces alterations in Ca2+ handling via SOCE. Methods: Male Wistar Kyoto (WKY) and Spontaneously Hypertensive (SHR) rats were subjected to the intake of increasing EtOH concentrations (5-20%, for 30 days). Systolic blood pressure (SBP) and EtOH concentration were measured; cardiovascular remodeling was assessed by histomorphometry; and function/ expression of STIM-1/Orai-1-mediated Ca2+ influx were evaluated by isometric contraction and western blot experiments. Results: Compared to the WKY-Control, our results show that: (1) chronic EtOH consumption caused a significant elevation of SBP in both strains; (2) cardiac hypertrophy and hypertrophic aortic wall remodeling much more pronounced in WKY-EtOH; (3) decreased capacity of ER to store and release Ca2+; (4) increased STIM-1/Orai-1-mediated SOCCs activation, which was selectively inhibited by YM-58483; and (5) increased expression of STIM-1 in WKY-EtOH and SHR-Control rats. Conclusion: These findings suggest that hypertrophic aortic remodeling and abnormal contraction triggered mainly by Ca2+ overload via STIM-1/Orai-1-mediated SOCE through SOCCs are involved hypertension developed by EtOH consumption.

Background: Sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, has endothelium protective and angiogenic effects. Objectives: To test if sildenafil improves tissue perfusion and neovascularization and downregulates proinflammatory molecules following limb ischemia. Methods: 30 ApoE-/- male mice, bred with cholesterol rich diet for 4 weeks, were anesthetized and underwent unilateral hind-limb ischemia with ligation of the left femoral artery. Mice were randomized in 2 groups: sildenafil (1 mg/Kg for 7 days intraperitoneally, i.p.) or normal saline (0.4 ml for 7 days, i.p.). Bilateral hind-limb perfusion was estimated by laser Doppler imaging after surgery on days 0, 7 and 28. Results: Sildenafil significantly reduced at day 28 compared with day 0 levels of soluble intracellular adhesion molecule-1(sICAM-1) [2.24(1.81-2.41) vs. 1.29(0.87-1.45) ng/ml, p=0,01], soluble E-selectin (sE-Selectin) [5.52 (3.67-6.14) vs 1.71 (1.42-2.86) ng/ml, p=0.02] and tissue plasminogen activator inhibitor- 1 (tPAI-1) [0.13(0.07-0.21) vs 0.08 (0.04-0.10) ng/ml, p=0.01] while normal saline had no effect on the levels of sICAM-1, sE-Selectin and tPAI-1. Treatment with sildenafil was associated with increased perfusion in the ischemic limb compared with controls. Conclusion: Sildenafil exerts significant beneficial effects on tissue perfusion and inflammatory status after limb ischemia, a finding implying neovascularization and potential vascular protective properties of sildenafil.