Platelet P-selectin expression is associated with atherosclerotic wall thickness in carotid artery in humans

Severe Allergy as a Chronic Inflammatory Condition From a Systems Biology Perspective

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

Effect of plateletcrit and methylenetetrahydrofolate reductase (MTHFR) C677T genotypes on folic acid efficacy in stroke prevention

Previous studies have shown that low platelet count combined with high plasma total homocysteine (tHcy) increased stroke risk and can be lowered by 73% with folic acid. However, the combined role of other platelet activation parameters and the methylenetetrahydrofolate reductase (MTHFR) C677T genotypes on stroke risk and folic acid treatment benefit remain to be examined. This study aimed to investigate if platelet activation parameters and MTHFR genotypes jointly impact folic acid treatment efficacy in first stroke prevention. Data were derived from the China Stroke Primary Prevention Trial. This study includes a total of 11,185 adult hypertensive patients with relevant platelet activation parameters and MTHFR genotype data. When simultaneously considering both platelet activation parameters (plateletcrit, platelet count, mean platelet volume, platelet distribution width) and MTHFR genotypes, patients with both low plateletcrit (Q1) and the TT genotype had the highest stroke incidence rate (5.6%) in the enalapril group. This subgroup significantly benefited from folic acid treatment, with a 66% reduction in first stroke (HR: 0.34; 95% CI: 0.14-0.82; p = 0.016). Consistently, the subgroup with low plateletcrit (Q1) and the CC/CT genotype also benefited from folic acid treatment (HR: 0.40; 95% CI: 0.23-0.70; p = 0.001). In Chinese hypertensive adults, low plateletcrit can identify those who may greatly benefit from folic acid treatment, in particular, those with the TT genotype, a subpopulation known to have the highest stroke risk.

High-Fat Diet Enhances Platelet Activation and Is Associated with Proprotein Convertase Subtilisin Kexin 9: An Animal Study

Platelet activation and proprotein convertase subtilisin kexin 9 (PCSK9) play pivotal roles in the progression of atherosclerosis to cardiovascular events. It has been reported that hyperlipidemia, a well-documented risk factors for cardiovascular diseases, tends increase platelet activation and PCSK9 expression. However, little is known about this specific mechanism, particularly how nutrition affects platelet activation and PCSK9 levels in hyperlipidemia conditions. This study aimed to assess how a high-fat diet influences platelet activation, its association with PCSK9, and the effects on blood pressure in an animal model. Here, male Wistar rats were divided into four groups, subjected to different high-fat diets for ten weeks with varying nutrient components. The results showed that high-fat diet-induced hypercholesterolemia and hypertriglyceridemia significantly increased the plasma levels of β-thromboglobulin (β-TG), p-selectin, and platelet factor 4 (PF-4). The blood pressure readings were also elevated post high-fat diet induction. Interestingly, the group with the highest percentage of saturated fatty acid and trans-fat exhibited the highest PCSK9 levels, along with the highest increase in plasma cholesterol, triglycerides, and platelet activation parameters. These findings confirm that high-fat diet-induced hypercholesterolemia and hypertriglyceridemia stimulate platelet activity and PCSK9 levels. Moreover, our results suggest that PCSK9, implicated in hypercholesterolemia and hypertriglyceridemia, may synergistically mediate platelet hyperactivity, aligning with clinical studies. Notably, our results highlight the association between a high-fat diet and PCSK9, providing insights for drug discovery targeting platelet activation in atherosclerosis-induced cardiovascular diseases.

Identification of crucial modules and genes associated with backfat tissue development by WGCNA in Ningxiang pigs

Fat deposition is an economically important trait in pigs. Ningxiang pig, one of the four famous indigenous breeds in China, is characterized by high fat content. The underlying gene expression pattern in different developmental periods of backfat tissue remains unclear, and the purpose of this investigation is to explore the potential molecular regulators of backfat tissue development in Ningxiang pigs. Backfat tissue (three samples for each stage) was initially collected from different developmental stages (60, 120, 180, 240, 300, and 360 days after birth), and histological analysis and RNA sequencing (RNA-seq) were then conducted. Fragments per kilobase of transcript per million (FPKM) method was used to qualify gene expressions, and differentially expressed genes (DEGs) were identified. Furthermore, strongly co-expressed genes in modules, which were named by color, were clustered by Weighted gene co-expression network analysis (WGCNA) based on dynamic tree cutting algorithm. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment were subsequently implemented, and hub genes were described in each module. Finally, QPCR analysis was employed to validate RNA-seq data. The results showed that adipocyte area increased and adipocyte number decreased with development of backfat tissue. A total of 1,024 DEGs were identified in five comparison groups (120 days vs. 60 days, 180 days vs. 120 days, 240 days vs. 180 days, 300 days vs. 240 days, and 360 days vs. 300 days). The turquoise, red, pink, paleturquoise, darkorange, and darkgreen module had the highest correlation coefficient with 60, 120, 180, 240, 300, and 360 days developmental stage, while the tan, black and turquoise module had strong relationship with backfat thickness, adipocyte area, and adipocyte number, respectively. Thirteen hub genes (ACSL1, ACOX1, FN1, DCN, CHST13, COL1A1, COL1A2, COL6A3, COL5A1, COL14A1, OAZ3, DNM1, and SELP) were recognized. ACSL1 and ACOX1 might perform function in the early developmental stage of backfat tissue (60 days), and FN1, DCN, COL1A1, COL1A2, COL5A1, COL6A3, and COL14A1 have unignorable position in backfat tissue around 120 days developmental stage. Besides, hub genes SELP and DNM1 in modules significantly associated with backfat thickness and adipocyte area might be involved in the process of backfat tissue development. These findings contribute to understand the integrated mechanism underlying backfat tissue development and promote the progress of genetic improvement in Ningxiang pigs.

Proteomic-Based Platelet Activation-Associated Protein SELP May Be a Novel Biomarker for Coagulation and Prognostic in Essential Thrombocythemia

Abnormal platelet activation can lead to thrombosis in essential thrombocythemia (ET) and thus impact patient prognosis. Platelet activation-associated proteins are key molecules for platelet activation. However, it is unclear which proteins are most closely associated with the disease's prognosis. To determine which platelet activation-related proteins can be employed as ET patient prognosis predictors, we used label-free quantification (LFQ) and parallel reaction monitoring (PRM) technology and first determined the serum proteomic expression levels and the differential proteins of ET patients. Then, based on the IPSET (International Prognostic Score for ET), the differential protein associated with the prognostic score was found. To investigate potential processes affecting prognosis, the connection of this protein with prognostic markers, such as thrombotic history, age, white blood cell count, coagulation factors, and inflammatory factors, were further examined. The levels of platelet activation-related proteins GPIbα, SELP, PF4, MMP1, and FLNA were significantly higher in ET patients, according to LFQ and PRM analyses (p < 0.01). Based on regression analysis of the IPSET prognostic score, it is suggested that the SELP level was positively correlated with the prognostic score and prognostic risk factor analysis (p < 0.05). Further regression analysis of SELP with coagulation factors showed that antithrombin (AT-III) was negatively correlated with SELP levels (p < 0.05). Further regression analysis of the inflammatory factors with AT-III and SELP revealed that IL-10, IL-12P70, and IL-31 were negatively correlated with AT-III and SELP (p < 0.01). Platelet activation pathway-related proteins are expressed more frequently in ET patients, and serum SELP may be a prognostic marker for these individuals by encouraging leukocyte increase and inflammatory factor expression and causing aberrant coagulation.

An Insight into Recent Advances on Platelet Function in Health and Disease

Platelets play a variety of roles in vascular biology and are best recognized as primary hemostasis and thrombosis mediators. Platelets have a large number of receptors and secretory molecules that are required for platelet functionality. Upon activation, platelets release multiple substances that have the ability to influence both physiological and pathophysiological processes including inflammation, tissue regeneration and repair, cancer progression, and spreading. The involvement of platelets in the progression and seriousness of a variety of disorders other than thrombosis is still being discovered, especially in the areas of inflammation and the immunological response. This review represents an integrated summary of recent advances on the function of platelets in pathophysiology that connects hemostasis, inflammation, and immunological response in health and disease and suggests that antiplatelet treatment might be used for more than only thrombosis.

Urinary Proteomic Profile of Arterial Stiffness Is Associated With Mortality and Cardiovascular Outcomes

Background

The underlying mechanisms of arterial stiffness remain not fully understood. This study aimed to identify a urinary proteomic profile to illuminate its pathogenesis and to determine the prognostic value of the profile for adverse outcomes.

Methods and Results

We measured aortic stiffness using pulse wave velocity (PWV) and analyzed urinary proteome using capillary electrophoresis coupled with mass spectrometry in 669 randomly recruited Flemish patients (mean age, 50.2 years; 51.1% women). We developed a PWV‐derived urinary proteomic score (PWV‐UP) by modeling PWV with proteomics data at baseline through orthogonal projections to latent structures. PWV‐UP that consisted of 2336 peptides explained the 65% variance of PWV, higher than 36% explained by clinical risk factors. PWV‐UP was significantly associated with PWV (adjusted β=0.73 [95% CI, 0.67–0.79]; P<0.0001). Over 9.2 years (median), 36 participants died, and 75 experienced cardiovascular events. The adjusted hazard ratios (+1 SD) were 1.46 (95% CI, 1.08–1.97) for all‐cause mortality, 2.04 (95% CI, 1.07–3.87) for cardiovascular mortality, and 1.39 (95% CI, 1.11–1.74) for cardiovascular events (P≤0.031). For PWV, the corresponding estimates were 1.25 (95% CI, 0.97–1.60), 1.35 (95% CI, 0.85–2.15), and 1.22 (95% CI, 1.02–1.47), respectively (P≥0.033). Pathway analysis revealed that the peptides in PWV‐UP mostly involved multiple pathways, including collagen turnover, cell adhesion, inflammation, and lipid metabolism.

Conclusions

PWV‐UP was highly associated with PWV and could be used as a biomarker of arterial stiffness. PWV‐UP, but not PWV, was associated with all‐cause mortality and cardiovascular mortality, implying that PWV‐UP–associated peptides may be multifaceted and involved in diverse pathological processes beyond arterial stiffness.

Advances in research on the effects of platelet activation in acute lung injury (Review)

Acute lung injury (ALI) is an acute hypoxic respiratory insufficiency or failure caused by various factors inside and outside the lungs. ALI is associated with high morbidity and a poor prognosis in hospitalized patients. The lungs serve as a reservoir for platelet precursor megakaryocytes and are closely associated with platelets. Platelets not only play a central role in hemostasis, coagulation and wound healing, but can also act as inflammatory cells capable of stimulating non-hemostatic immune functions under inflammatory conditions, participating in the progression of various inflammatory diseases, and can result in tissue damage. Therefore, it was speculated that platelets may play an important role in the pathogenesis of ALI. In this review, the latest research progress on secretion of bioactive mediators from platelets, platelet activation-related signaling pathways, and the direct contact reactions between platelets and neutrophils with endothelial cells that result in ALI are described, providing evidence to support the importance of the consideration of platelets in the search for ALI interventional targets.

Matrix metalloproteinase-2 on activated platelets triggers endothelial PAR-1 initiating atherosclerosis

AIMS 

Platelets participate in atherogenesis with mechanisms not yet fully clarified. Vascular wall MMP-2 is involved in the arterial remodelling accompanying atherosclerosis. Platelets contain and release MMP-2 but no informations are available on its role in atherosclerotic lesion formation.

METHODS AND RESULTS 

We generated double knockout mice lacking the LDL receptor and MMP-2 only in circulating blood cells showing that they develop significantly lesser femoral intima thickening after photochemical-induced arterial damage and atherosclerotic lesions in the aorta, measured by the en face method, after 4 months of atherogenic diet. Moreover, repeated transfusions of autologous-activated platelets in LDLR-/- mice on atherogenic diet significantly enhanced the extension of aortic atherosclerotic lesions while transfusion of activated platelets from MMP-2-/- mice did not. In vitro coincubation studies showed that platelet-derived MMP-2 plays a pivotal role in the development and progression of atherosclerosis through a complex cross-talk between activated platelets, monocyte/macrophages, and endothelial cells. Translational studies in patients with CAD and chronic HIV infection showed that platelet surface expression of MMP-2 highly significantly correlated with the degree of carotid artery stenosis.

CONCLUSION 

We show a previously unknown mechanism of the pathway through which platelets expressing MMP-2 trigger the initial phases of atherosclerosis and provide a mechanism showing that they activate endothelial PAR-1 triggering endothelial p38MAPK signalling and the expression of adhesion molecules. The development of drugs blocking selectively platelet MMP-2 or its expression may represent a new approach to the prevention of atherosclerosis.

Predictive value of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio for primary patency of percutaneous transluminal angioplasty in hemodialysis arteriovenous fistula stenosis

OBJECTIVE

The aim of this study is to investigate the potential association of the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) with the primary patency of percutaneous transluminal angioplasty (PTA) in hemodialysis arteriovenous fistula (AVF) stenosis.

METHODS

This study conducted a retrospective review of patients with end-stage renal disease referred for hemodialysis AVF stenosis in one center. The study consisted of 114 patients with significant (significant stenosis was defined as a reduction in the caliber of the fistula vein of > 50% with respect to the non-aneurysmal venous segment). AVF stenosis patients were treated with PTA, with conventional balloon angioplasty. The NLR and PLR were calculated from the pre-interventional blood samples. The patients were classified into two groups: group A, primary patency < 12 months (n = 35) and group B, and primary patency ≥ 12 months (n = 79). Comparisons between the groups were performed using the Mann-Whitney U test. Kaplan-Meier analysis was performed to compare the factors, NLR and PLR, for association with primary patency AVFs. A receiver-operating characteristic curve analysis was performed to identify the sensitivity and specificity of the NLR and PLR cut-off values in the prediction of primary patency time.

RESULTS

There was no difference in gender; age; side of AVF; AVF type; comorbid diseases such as diabetes mellitus and hypertension; or blood parameters such as white cell count, erythrocytes, hemoglobin, neutrophils, lymphocytes, monocytes, eosinophils, basophils, C-reactive protein, NLR, or PLR between the two groups (p > 0.05). There was also no significant difference in the patency rate between the NLR < 4.13 and NLR ≥ 4.13 groups at 12 months (NLR cut-off point = 4.13, p = 0.273). There were statistically significant differences between the primary patency rates of the PLR < 187.86 and PLR ≥ 187.86 groups at 12 months (PLR cut-off point = 187.86, p = 0.023). The cut-off value for PLR for the determination of primary patency was 187.86, with a sensitivity of 57.0% and specificity of 34.4%.

CONCLUSION

An increased level of PLR may be a risk factor for the development of early AVF restenosis after successful PTA. However, more studies are needed to validate this finding.

Understanding the Impact of Perfluorinated Compounds on Cardiovascular Diseases and Their Risk Factors: A Meta-Analysis Study

Perfluorinated compounds (PFCs) are non-biodegradable synthetic chemical compounds that are widely used in manufacturing many household products. Many studies have reported the association between PFCs exposure with the risk of developing cardiovascular diseases (CVDs). However, those reports are still debatable, due to their findings. Thus, this review paper aimed to analyse the association of PFCs compound with CVDs and their risk factors in humans by systematic review and meta-analysis. Google Scholar, PubMed and ScienceDirect were searched for PFCs studies on CVDs and their risk from 2009 until present. The association of PFCs exposure with the prevalence of CVDs and their risk factors were assessed by calculating the quality criteria, odds ratios (ORs), and 95% confidence intervals (CIs). CVDs risk factors were divided into serum lipid profile (main risk factor) and other known risk factors. The meta-analysis was then used to derive a combined OR test for heterogeneity in findings between studies. Twenty-nine articles were included. Our meta-analysis indicated that PFCs exposure could be associated with CVDs (Test for overall effect: z = 2.2, p = 0.02; Test for heterogeneity: I² = 91.6%, CI = 0.92–1.58, p < 0.0001) and their risk factors (Test for overall effect: z = 4.03, p < 0.0001; Test for heterogeneity: I² = 85.8%, CI = 1.00–1.14, p < 0.0001). In serum lipids, total cholesterol levels are frequently reported associated with the exposure of PFCs. Among PFCs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) exposure increased the risk of CVDs than other types of PFCs. Although the risk of PFOA and PFOS were positively associated with CVDs and their risk factors, more observational studies shall be carried out to identify the long-term effects of these contaminants in premature CVDs development in patients.

Coronary microvascular injury in myocardial infarction: perception and knowledge for mitochondrial quality control

Endothelial cells (ECs) constitute the innermost layer in all blood vessels to maintain the structural integrity and microcirculation function for coronary microvasculature. Impaired endothelial function is demonstrated in various cardiovascular diseases including myocardial infarction (MI), which is featured by reduced myocardial blood flow as a result of epicardial coronary obstruction, thrombogenesis, and inflammation. In this context, understanding the cellular and molecular mechanisms governing the function of coronary ECs is essential for the early diagnosis and optimal treatment of MI. Although ECs contain relatively fewer mitochondria compared with cardiomyocytes, they function as key sensors of environmental and cellular stress, in the regulation of EC viability, structural integrity and function. Mitochondrial quality control (MQC) machineries respond to a broad array of stress stimuli to regulate fission, fusion, mitophagy and biogenesis in mitochondria. Impaired MQC is a cardinal feature of EC injury and dysfunction. Hence, medications modulating MQC mechanisms are considered as promising novel therapeutic options in MI. Here in this review, we provide updated insights into the key role of MQC mechanisms in coronary ECs and microvascular dysfunction in MI. We also discussed the option of MQC as a novel therapeutic target to delay, reverse or repair coronary microvascular damage in MI. Contemporary available MQC-targeted therapies with potential clinical benefits to alleviate coronary microvascular injury during MI are also summarized.

Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis?~ Its Clinical Implications, Limitations, and Future Perspectives ~

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter β is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter β is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter β is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter β improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter β of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.

The multifaceted contribution of platelets in the emergence and aftermath of acute cardiovascular events

Atherosclerosis is an underlying cause of a broad array of cardiovascular diseases characterized by plaques, arterial wall thickening initiated by hyperlipidemia, pro-inflammatory signals, endothelial dysfunction and the influx of inflammatory cells. By still incompletely characterized mechanisms, these plaques can destabilize or erode, leading to thrombosis and blood vessel occlusion and becomes clinically manifest as angina pectoris, myocardial infarction (MI) or stroke. Among the several blood cell types that are involved in the development of atherosclerosis, the role of platelets during the thrombotic occlusion of ruptured or eroded plaques is well established and clinically exploited as evident by the extensive use of platelet inhibitors. However, there is increasing evidence that platelets are also involved in the earlier stages of atheroma development by exhibiting pro-inflammatory activities. The scope of this review is to describe the role of platelets in the initiation and propagation stages of atherosclerosis and beyond; in atherothrombotic complications.

Vascular protective effect of aspirin and rivaroxaban upon endothelial denudation of the mouse carotid artery

While in recent trials the dual pathway inhibition with aspirin plus rivaroxaban has shown to be efficacious in patients with atherosclerotic cardiovascular disease, little is known about the effects of this combination treatment on thrombus formation and vascular remodelling upon vascular damage. The aim of this study was to examine the effects of aspirin and/or rivaroxaban on injury-induced murine arterial thrombus formation in vivo and in vitro, vessel-wall remodelling, and platelet-leukocyte aggregates. Temporary ligation of the carotid artery of C57BL/6 mice, fed a western type diet, led to endothelial denudation and sub-occlusive thrombus formation. At the site of ligation, the vessel wall stiffened and the intima-media thickened. Aspirin treatment antagonized vascular stiffening and rivaroxaban treatment led to a positive trend towards reduced stiffening. Local intima-media thickening was antagonized by both aspirin or rivaroxaban treatment. Platelet-leukocyte aggregates and the number of platelets per leukocyte were reduced in aspirin and/or rivaroxaban treatment groups. Furthermore, rivaroxaban restricted thrombus growth and height in vitro. In sum, this study shows vascular protective effects of aspirin and rivaroxaban, upon vascular injury of the mouse artery.

Platelet Function in Cardiovascular Disease: Activation of Molecules and Activation by Molecules

Globally, one of the major causes of death is the cardiovascular disease (CVD), and platelets play an important role in thrombosis and atherosclerosis that led to death. Platelet activation can be done by different molecules, genes, pathways, and chemokines. Lipids activate platelets by inflammatory factors, and platelets are activated by receptors of peptide hormones, signaling and secreted proteins, microRNAs (miRNAs), and oxidative stress which also affect the platelet activation in older age. In addition, surface molecules on platelets can interact with other cells and chemokines in activated platelets and cause inflammation thrombosis events and CVD. However, these molecules activating platelets or being activated by platelets can be suggested as the markers to predict the clinical outcome of CVD and can be targeted to reduce thrombosis and atherosclerosis. However, hindering these molecules by other factors such as genes and receptors can reduce platelet activation and aggregation and targeting these molecules can control platelet interactions, thrombosis, and CVD. In addition, dual therapy with the receptor blockers and novel drugs results in better management of CVD patients. Overall, our review will emphasize on the molecules involved in the activation of platelets and on the molecules that are activated by platelets in CVD and discuss the molecules that can be blocked or targeted to reduce the thrombosis events and control CVD.

Expression of Blood Cells Associated CD Markers and Cardiovascular Diseases: Clinical Applications in Prognosis

BACKGROUND

Cardiovascular diseases (CVDs) are a major cause of mortality worldwide. The results of various studies have shown that abnormality in the frequency and function of blood cells can be involved in CVD complications. In this review, we have focused on abnormalities in the expression of the CD (cluster of differentiation) markers of blood cells to assess the association of these abnormalities with CVD prognosis.

METHODS

We identified the relevant literature through a PubMed search (1990-2018) of English-language articles using the terms "Cardiovascular diseases", "CD markers", "leukocytes", "platelets", and "endothelial cells".

RESULTS

There is a variety of mechanisms for the effect of CD-marker expressions on CVDs prognosis, ranging from proinflammatory processes to dysfunctional effects in blood cells.

CONCLUSION

Considering the possible effects of CD-marker expression on CVDs prognosis, particularly prognosis of acute myocardial infarction and atherosclerosis, long-term studies in large cohorts are required to identify the prognostic value of CD markers and to target them with appropriate therapeutic agents.

Risk factors and pregnancy outcomes associated with retinopathy in patients presenting with severe preeclampsia: A retrospective cohort study

The visual system was reported to be affected in over half of patients with preeclampsia (PE), though fundus examination was performed only among patients complaining of visual symptoms. Delayed diagnosis and treatment of PE-related retinopathy may lead to permanent visual impairment. Therefore, we hypothesize that some clinical or laboratory parameters could predict severity of retinal damage.The aim of the study was to explore the risk factors for retinopathy in severe preeclampsia (sPE) and investigate pregnancy outcomes with different degrees of retinopathy.This retrospective cohort study included women with sPE who underwent ophthalmoscopy and delivered after admission to West China Second University Hospital, between June 2013 and December 2016. Clinical and laboratory characteristics were retrieved from medical records. Patients confirmed with retinopathy were followed up with telephones. Multiple logistic regression analysis was performed to identify risk factors of PE-related retinopathy.Five hundred thirty-four patients were included, of which 17.6% having stage-1/2 retinopathy, 14.6% having stage-3/4 retinopathy, and 67.8% having normal retina. Compared with patients without retinopathy, patients with stage 3/4 retinopathy were more likely to have preterm-birth and low-birth-weight babies. Significant risk factors for stage 3/4 retinopathy in sPE included severe hypertension (odds ratio [OR] 2.24, 95% confidence interval [CI]: 1.10-4.56), elevated white blood cell (WBC) counts (OR 1.88, 95% CI: 1.05-3.35), decreased platelet counts (OR 2.12, 95% CI: 1.07-4.48), lactate dehydrogenase (LDH) concentration of >800 IU/L (OR 2.31, 95% CI: 1.05-5.06), low hemoglobin (HGB) concentrations of <110 g/L (OR 3.73, 95% CI: 1.21-11.47), 24-hour proteinuria of 2 to 5 g (OR 6.39, 95% CI: 2.84-14.39), and >5 g (OR 8.66, 95% CI: 3.67-20.44).This study confirms the association between retinopathy and preterm-birth and low-birth weight in sPE. The risk factors for severe PE-related retinopathy, including severe hypertension, platelet and WBC count, HGB and LDH concentration, and proteinuria, are associated with the development of retinopathy. Routine and repeated fundus examination is recommended for maternal monitoring in sPE.

Increased Cardiovascular Risk Associated with Chemical Sensitivity to Perfluoro-Octanoic Acid: Role of Impaired Platelet Aggregation

Perfluoro–alkyl substances (PFAS), particularly perfluoro–octanoic acid (PFOA), are persisting environmental chemicals showing bioaccumulation in human tissues. Recently, exposure to PFAS has been associated with increased prevalence of cardiovascular diseases (CVDs). However, a causal role of PFAS in atherosclerosis pathogenesis is under-investigated. Here, we investigated the effect of PFOA exposure on platelets’ function, a key player in atherosclerosis process. PFOA accumulation in platelets was evaluated by liquid chromatography-mass spectrometry. Changes in platelets’ membrane fluidity and activation after dose-dependent exposure to PFOA were evaluated by merocyanine 540 (MC540) and anti P-Selectin immune staining at flow cytometry, respectively. Intracellular calcium trafficking was analyzed with Fluo4M probe, time-lapse live imaging. Platelets’ aggregation state was also evaluated with Multiplate^® aggregometry analyzer in 48 male subjects living in a specific area of the Veneto region with high PFAS environmental pollution, and compared with 30 low-exposure control subjects. Platelets’ membrane was the major target of PFOA, whose dose-dependent accumulation was associated in turn with increased membrane fluidity, as expected by a computational model; increased activation at resting condition; and both calcium uptake and aggregation upon activation. Finally, exposed subjects had higher serum and platelets levels of PFOA, together with increased aggregation parameters at Multiplate^®, compared with controls. These data help to explain the emerging association between PFAS exposure and CVD.

Policosanol Attenuates Cholesterol Synthesis via AMPK Activation in Hypercholesterolemic Rats

This study was carried out to investigate the effects of policosanol on high-fat and high-cholesterol diet-induced hypercholesterolemic rats to provide strong evidence in support of its hypocholesterolemic effect. The hypercholesterolemic rats showed elevations in liver weight, total triglycerides, total cholesterol, and low-density lipoprotein (LDL) cholesterol in serum; however, policosanol supplementation reduced these markers significantly. In addition, we found that policosanol supplementation stimulated an increase in fecal cholesterol and bile acid contents and deactivated 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase by AMP-activated protein kinase (AMPK) phosphorylation during high-fat and high-cholesterol-containing diet-induced development of hypercholesterolemia. Policosanol supplementation decreased ApoB levels and increased LDL-receptor expression, but it did not affect the hepatic ACAT2 level in livers from hypercholesterolemic rats. Moreover, supplementation with policosanol significantly decreased aortic wall thickness and levels of P-selectin and soluble vascular cell adhesion molecule (sVCAM-1) in serum. In conclusion, we suggest that policosanol supplementation induces antihypercholesterolemia by inhibiting cholesterol biosynthesis, LDL cholesterol uptake, and cholesterol excretion.

Platelet to lymphocyte ratio correlates with diabetic foot risk and foot ulcer in patients with type 2 diabetes

Diabetic foot ulcer is a major complication in patients with diabetes. Platelet-lymphocyte ratio (PLR) has been reported to have a predictive effect to some diabetic complications in recent years. However, it has not been fully elucidated about the relationship between diabetic foot risk or diabetic foot ulcer and PLR in patients with type 2 diabetes. Therefore, we aimed to evaluate this relationship. In this cross-sectional study, we evaluated the relationships between patient's diabetic foot risk with the criteria of the International Working Group on the Diabetic Foot (IWGDF) and prevalent foot ulcer, and PLR in 453 consecutive patients with type 2 diabetes. Propensity score analysis was used to adjust the difference of covariates; age, sex, duration of diabetes, body mass index (BMI), HbA1c, current smoking, hypertension, dyslipidemia, neuropathy, PAD, foot deformity and history of foot ulcers. PLR was higher in patients with high risk diabetic foot or foot ulcer (117 ± 40 vs. 107 ± 31, p = 0.003 and 148 ± 65 vs. 113 ± 56, p < 0.001). A receiver-operating characteristic curve demonstrated that PLR of 130.6 constitutes the cut-off value for prevalent foot ulcer with sensitivity 0.85 and specificity 0.70. Multivariate logistic regression analysis revealed that PLR was positively correlated with prevalent foot ulcer (odds ratio, 1.02; 95% confidence interval 1.01-1.04, p = 0.003) after adjusted for several variables with propensity score analysis. Our results demonstrated that PLR can be a marker for high risk diabetic foot and diabetic foot ulcer in patients with type 2 diabetes.

Increased Neutrophil-lymphocyte and Platelet-lymphocyte Ratios in Male Heroin Addicts: A Prospective Controlled Study

Objective

The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are markers that can determine the presence of systemic inflammatory response. In this study, we examined the NLR and PLR levels in patients with heroin dependence compared to healthy controls.

Methods

The study sample included 90 male patients with heroin dependence aged 18 to 45 years and 60 healthy subjects who had similar socio-demographic characteristics as the patient group. The diagnoses of heroin dependence and other Axis I psychiatric disorders in the patient and control groups were screened with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID-I). The extent of heroin addiction was assessed with the Addiction Severity Index (ASI).

Results

The mean NLR and PLR levels of patients with heroin dependence were significantly higher than the control subjects (p=0.031 and p<0.001, respectively). Positive correlations were found between NLR, PLR and duration of the disorder.

Conclusion

Our results indicate that inflammatory processes may play a role in the pathophysiology of heroin dependence.

Increased levels of platelet activation markers are positively associated with carotid wall thickness and other atherosclerotic risk factors in obese patients

The role of platelets in the development of atherosclerosis and obesity-related prothrombotic state is still under investigation. In this cross-sectional cohort study, we measured the levels of different platelet activation markers and evaluated their relationship with carotid intima-media thickness (IMT) along with other atherosclerotic risk factors in obese patients with or without atherosclerotic co-morbidities. We enrolled 154 obese patients, including 98 with either hypertension, type 2 diabetes mellitus or dyslipidaemia, 56 without these co-morbidities and 62 age- and sex-matched healthy controls. Platelet P-selectin expression and the number of platelet-derived microparticles (PMPs) were measured by flow cytometry; soluble P-selectin levels were analysed by ELISA and Thr715Pro P-selectin polymorphism was determined by PCR-RFLP. Carotid IMT was examined by ultrasonography. The levels of platelet activation parameters were significantly elevated in all obese subjects with increased carotid IMT compared to healthy controls. There was no effect of Thr715Pro genotype on soluble P-selectin levels in obese individuals contrary to normal subjects. Significant and positive association was revealed between carotid IMT and platelet P-selectin (p<0.0001), soluble P-selectin (p=0.039) and PMP (p=0.0001) levels. After adjusting for multiple variables, independent association was found between soluble P-selectin and fibrinogen (p=0.007), PMP levels and body mass index (p<0.0001) as well as platelet P-selectin and carotid IMT (p=0.012) plus plasminogen activator inhibitor-1 (p=0.009). In conclusion, P-selectin and PMP levels showed positive associations with abnormal carotid IMT and other risk factors in obesity suggesting a critical role of enhanced platelet reactivity in atherosclerotic wall alteration.

CD4+ T cells in atherosclerosis: Regulation by platelets

Atherosclerosis is an inflammatory and thrombotic disease, in which both CD4+ T cells and platelets play important roles throughout all stages of atherogenesis. CD4+ T cells are the most abundant T cells present in atherosclerotic lesions. They are primarily seen as type 1 T helper (Th1) cells, while the other CD4+ T cell subsets Th2, Th17, and regulatory T (Treg) cells are also found in the lesions with lower frequencies. CD4+ T effector cells release various cytokines, which exert paracrine or autocrine effects among different CD4+ T cell subsets and other lesional cells and subsequently modulate inflammatory processes in the lesions. Platelets are instrumental in thrombosis and haemostasis, but also play important regulatory roles in immune response, inflammation, and angiogenesis. The present review summarises the current knowledge and/or understanding on how platelets regulate recruitment, activation, differentiation, and cytokine production of different CD4+ T cell subsets, as well as impacts of the platelet-CD4+ T cell interactions on atherogenesis. The research perspectives of platelet-CD4+ T cell interaction in atherosclerosis are also discussed.

Cortistatin reduces atherosclerosis in hyperlipidemic ApoE-deficient mice and the formation of foam cells

Atherosclerosis is a chronic inflammatory cardiovascular disease that is responsible of high mortality worldwide. Evidence indicates that maladaptive autoimmune responses in the arterial wall play critical roles in the process of atherosclerosis. Cortistatin is a neuropeptide expressed in the vascular system and atherosclerotic plaques that regulates vascular calcification and neointimal formation, and inhibits inflammation in different experimental models of autoimmune diseases. Its role in inflammatory cardiovascular disorders is largely unexplored. The aim of this study is to investigate the potential therapeutic effects of cortistatin in two well-established preclinical models of atherosclerosis, and the molecular and cellular mechanisms involved. Systemic treatment with cortistatin reduced the number and size of atherosclerotic plaques in carotid artery, heart, aortic arch and aorta in acute and chronic atherosclerosis induced in apolipoprotein E-deficient mice fed a high-lipid diet. This effect was exerted at multiple levels. Cortistatin reduced Th1/Th17-driven inflammatory responses and increased regulatory T cells in atherosclerotic arteries and lymphoid organs. Moreover, cortistatin reduced the capacity of endothelial cells to bind and recruit immune cells to the plaque and impaired the formation of foam cells by enhancing cholesterol efflux from macrophages. Cortistatin emerges as a new candidate for the treatment of the clinical manifestations of atherosclerosis.

Connecting genetic risk to disease end points through the human blood plasma proteome

Genome-wide association studies (GWAS) with intermediate phenotypes, like changes in metabolite and protein levels, provide functional evidence to map disease associations and translate them into clinical applications. However, although hundreds of genetic variants have been associated with complex disorders, the underlying molecular pathways often remain elusive. Associations with intermediate traits are key in establishing functional links between GWAS-identified risk-variants and disease end points. Here we describe a GWAS using a highly multiplexed aptamer-based affinity proteomics platform. We quantify 539 associations between protein levels and gene variants (pQTLs) in a German cohort and replicate over half of them in an Arab and Asian cohort. Fifty-five of the replicated pQTLs are located in trans. Our associations overlap with 57 genetic risk loci for 42 unique disease end points. We integrate this information into a genome-proteome network and provide an interactive web-tool for interrogations. Our results provide a basis for novel approaches to pharmaceutical and diagnostic applications.

Individual genetic variation can affect the levels of protein in blood, but detailed data sets linking these two types of data are rare. Here, the authors carry out a genome-wide association study of levels of over a thousand different proteins, and describe many new SNP-protein interactions.

Platelets and cardiovascular risk

Atherosclerosis and its late sequels are still the number one cause of death in Western societies. Platelets are a driving force not only during the genesis of atherosclerosis, but especially in its late stages, as evidenced by complications such as arterial thrombosis, myocardial infarction, and ischaemic stroke. Platelets are small, anucleate blood elements of critical importance in cardiovascular disease, a major cause of morbidity and mortality. Numerous risk scores exist to identify healthy individuals at increased risk of developing atherosclerosis and cardiovascular disease. However, markers of cardiovascular risk not routinely assessed (i.e. platelet activity, mean platelet volume and P-selectin) may also contribute to be useful in calculating cardiovascular risk. The present review and meta-analysis summarizes the evidence for measuring platelet function indices to identify patients at risk of developing cardiovascular events.

Measurement of residual platelet thrombogenicity under arterial shear conditions in cerebrovascular disease patients receiving antiplatelet therapy

Essentials A consensus methodology for assessing the effects of antiplatelet agents has not been established. Measuring platelet thrombus formation (PTF) for evaluating antiplatelet effects was assessed. PTF differentially reflected antiplatelet effects compared to other tests. PTF may be associated with the severity of carotid or intracranial arterial stenosis. Click to hear a presentation on platelet function testing in the clinic by Gresele and colleagues

SUMMARY

Background A consensus methodology for assessing the effects of antiplatelet agents has not been established. Objective We investigated the usefulness of directly measuring platelet thrombus formation (PTF) using a microchip-based flow chamber system for evaluating antiplatelet therapy. Patients/Methods Platelet thrombus formation in the whole blood of 94 patients with ischemic cerebrovascular disease treated with clopidogrel and/or aspirin was measured in a flow chamber system at a shear rate of 1500 s(-1) and was compared with the results of assays for agonist-induced platelet aggregability, phosphorylation of vasodilator-stimulated phosphoprotein, platelet p-selectin expression (PS), and platelet-monocyte complexes. Results In all patients tested, area under the flow pressure curve (AUC10), which represents platelet thrombogenicity, showed weak correlation with platelet aggregation induced by either adenosine diphosphate or collagen. In addition, AUC10 was lower in patients treated with dual antiplatelet therapy (median 79.4) compared with patients treated with aspirin or clopidogrel alone (217.7 and 301.0, respectively), whereas the parameters evaluated by the other assays did not reflect the combined treatment efficacy. In clopidogrel monotherapy patients, AUC10 was associated with the severity of arterial stenosis (R(2) = 0.127, β = 1.25), and AUC10 and PS were higher in patients with severe carotid or intracranial arterial stenosis than in those with mild stenosis. Conclusions Platelet thrombus formation measurement using a flow-chamber system was useful for evaluating the efficacy of treatment with aspirin and clopidogrel, both alone and in combination. The present findings indicate that high residual platelet thrombogenicity in patients treated with clopidogrel may be associated with the severity of carotid or intracranial arterial stenosis.

Cholesterol in platelet biogenesis and activation

Hypercholesterolemia is a risk factor for atherothrombotic disease, largely attributed to its impact on atherosclerotic lesional cells such as macrophages. Platelets are involved in immunity and inflammation and impact atherogenesis, primarily by modulating immune and inflammatory effector cells. There is evidence that hypercholesterolemia increases the risk of atherosclerosis and thrombosis by modulating platelet biogenesis and activity. This review highlights recent findings on the impact of aberrant cholesterol metabolism on platelet biogenesis and activity and their relevance in atherosclerosis and thrombosis.

A Statistical Approach for Testing Cross-Phenotype Effects of Rare Variants

Increasing empirical evidence suggests that many genetic variants influence multiple distinct phenotypes. When cross-phenotype effects exist, multivariate association methods that consider pleiotropy are often more powerful than univariate methods that model each phenotype separately. Although several statistical approaches exist for testing cross-phenotype effects for common variants, there is a lack of similar tests for gene-based analysis of rare variants. In order to fill this important gap, we introduce a statistical method for cross-phenotype analysis of rare variants using a nonparametric distance-covariance approach that compares similarity in multivariate phenotypes to similarity in rare-variant genotypes across a gene. The approach can accommodate both binary and continuous phenotypes and further can adjust for covariates. Our approach yields a closed-form test whose significance can be evaluated analytically, thereby improving computational efficiency and permitting application on a genome-wide scale. We use simulated data to demonstrate that our method, which we refer to as the Gene Association with Multiple Traits (GAMuT) test, provides increased power over competing approaches. We also illustrate our approach using exome-chip data from the Genetic Epidemiology Network of Arteriopathy.

Metformin ameliorates the proinflammatory state in patients with carotid artery atherosclerosis through sirtuin 1 induction

Metformin is a widely used classic antidiabetic drug. However, its clinical pharmacologic mechanism remains poorly understood. In the present study, we investigated the anti-inflammatory effects of metformin on circulating peripheral blood mononuclear cells (MNCs) of patients with carotid artery atherosclerosis (AS). A total of 42 patients with carotid artery AS were randomly assigned to metformin (500 mg twice a day; Met; n = 21) or placebo control (Con; n = 21) groups. After 12 weeks of treatment, plasma concentrations of high-sensitivity C-reactive protein (hs-CRP), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α) significantly decreased in the Met group compared with the Con group. In addition, treatment with metformin significantly reduced the expression of IL-6 and TNF-α at the messenger RNA level and attenuated nuclear factor kappa B (NF-κB) DNA binding activity in MNCs. Intriguingly, metformin did not alter the expression of NF-κB p65 subunit, but markedly inhibited its acetylation. Furthermore, metformin significantly induced sirtuin 1 (SIRT1) expression in MNCs. Moreover, we found that metformin treatment dramatically induced SIRT1 expression, blocked p65 acetylation, and inhibited NF-κB activity and the expression of inflammatory factors in MNCs in vitro. We conclude that metformin has a novel direct protective role to ameliorate the proinflammatory response through SIRT1 induction, p65 acetylation reduction, NF-κB inactivation, and inflammatory inhibition in peripheral blood MNCs of patients with carotid artery AS.

Platelet to lymphocyte ratio and neutrophil to lymphocyte ratio in patients with rheumatoid arthritis

OBJECTIVES

It has been well documented that the platelet to lymphocyte ratio (PLR) and the neutrophil to lymphocyte ratio (NLR) are associated with outcomes for patients with gastric cancer, non-small cell lung cancer and acute heart failure. Inflammation may be the hidden factor that explains the correlation between NLP, PLR, and these diseases. However, to date, the data concerning NLR, PLR, and its association with inflammation are lacking in patients with rheumatoid arthritis (RA), thus, our aim to discuss whether NLR and PLR are associated with RA.

METHODS

Patients with RA and healthy individuals were included according to the determined criteria, and laboratory indicators were measured.

RESULTS

PLR and NLR were significantly higher in RA patients compared with healthy controls (3.20±2.06 vs. 1.56±0.47, P<0.01; 192.85±101.78 vs. 103.49±28.68, P<0.01). When leukocytes, neutrophil percentage, neutrophil, lymphocyte, platelet, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF) were considered as confounders (crude model), our results indicated that ESR and RF were correlated to RA. Of note, ESR, RF, and PLR were associated with RA after further adjustment based on crude model for PLR and NLR. Receiver operating characteristic (ROC) curves analysis showed that PLR values higher than >115.7 evaluated RA with a sensitivity of 82.5%, a specificity of 74.8% and area under the curve ( AUC ) of 0.847.

CONCLUSIONS

Our results suggest that PLR is associated with RA, and PLR may be an underlying indicator indicating the chronic subclinical inflammation in patients with RA.

Platelets and the complement cascade in atherosclerosis

Atherosclerosis and its late sequels are still the number one cause of death in western societies. Platelets are a driving force not only during the genesis of atherosclerosis, but especially in its late stages, as evidenced by complications such as arterial thrombosis, myocardial infarction, and ischemic stroke. Atherosclerosis is increasingly recognized as an inflammatory disease, influenced by various immune mechanisms. The complement system is part of our innate immune system, and its diverse roles in atherosclerosis have become evident over the past years. In this review we identify points of intersection between platelets and the complement system and discuss their relevance for atherosclerosis. Specifically, we will focus on roles for platelets in the onset as well as progression of the disease, a possible dual role for complement in the genesis and development of atherosclerosis, and review emerging literature revealing previously unrecognized cross-talk between platelets and the complement system and discuss its possible impact for atherosclerosis. Finally, we identify limitations of current research approaches and discuss perspectives of complement modulation in the control of the disease.

Determinants of platelet-leukocyte aggregation and platelet activation in stroke

BACKGROUND

Platelet-leukocyte aggregation (PLA) and platelet activation are found to be on the higher side in ischemic stroke patients. The correlation of PLA with clinical features has not been intensively investigated and the influence of genetic factors on PLA is still unexplored. The interaction of platelets with leukocytes is mainly determined by the proteins encoded by six genes: P-Selectin (SELP encodes CD62P) on the thrombocyte binding to P-Selectin-Glycoprotein-Ligand-1 (PSGL1) on the leukocyte, intracellular-adhesion-molecule 2 (ICAM2) interacting with Integrin alpha M (ITGAM) and Glycoprotein 1b-alpha (GP1BA) binding to Integrin alpha L (ITGAL).

METHODS

Seventy-nine patients with acute ischemic stroke and 151 controls without vascular disease from a single German center were enrolled. A neurologist and a neuroradiologist ascertained clinical and radiological features. PLA and platelet activation were analyzed using flow cytometry with various antibodies. Coding as well as tagging SNPs in six genes determining PLA were genotyped. Three groups of parameters were correlated with each other: (i) clinical and radiological parameters, (ii) laboratory parameters, (iii) genetic parameters. For the comparisons, robust nonparametric statistical tests were applicable.

RESULTS

PLA and platelet activation were higher in ischemic stroke patients compared to controls. Both, anticoagulant and antiplatelet treatment in the patient group affected platelet activation but not PLA. PLA correlated weakly with measures of stroke severity but not with thrombus length or stroke etiology. The association of SNP rs2228315 in the P-Selectin Glycoprotein Ligand-1-gene (PSGL1) with ischemic stroke and platelet activation was significant before correction for multiple testing while a trend was observed for the association with PLA. Regression analysis revealed that (i) platelet activation was an independent determinant of stroke, (ii) that PLA correlated with stroke, sex, age and platelet activation and (iii) that platelet activation correlated only with stroke. None of the SNPs survived in the regression analysis for stroke, PLA or platelet activation as dependent variables.

CONCLUSIONS

The most important result of our study is that PLA and platelet activation are independent of other vascular risk factors correlated with stroke in our sample. In addition, we identified the missense SNP rs2228315 in the PSGL1-gene as a candidate polymorphism for ischemic stroke-related PLA. Association between this SNP and stroke as well as coronary artery disease has also been shown by two other studies.

Sleep, cardiac autonomic function, and carotid atherosclerosis in patients with cardiovascular risks: HSCAA study

OBJECTIVES

Behavioral and psychosocial factors have been gaining increased attention in regard to cardiovascular diseases. We evaluated sleep conditions, cardiac autonomic function, and carotid atherosclerosis in subjects who participated in the Hyogo Sleep Cardio-Autonomic Atherosclerosis (HSCAA) Study.

METHODS

This cross-sectional study included 330 serial patients registered in the HSCAA study who were free from past cardiovascular diseases, and prescribing α- or β-blockers. In addition to clinical background and classical cardiovascular risk factors, sleep efficiency, apnea hypopnea index (AHI), awake physical activity, heart rate variability (HRV), carotid intima-media thickness (IMT), presence of plaque and plaque score were determined.

RESULTS

Sleep efficiency (r = -0.183) and all HRV parameters (SDNN: r = -0.202; rMSSD: r = -0.234; pNN50: r = -0.277) were significantly (p < 0.01) and negatively associated with IMT, while AHI (r = 0.220, p < 0.001) was positively associated with IMT. Similarly, sleep efficiency (r = -0.129), HRV parameters (SDNN: r = -0.170; rMSSD: r = -0.217; pNN50: r = -0.260) and AHI (r = 0.184) were also significantly (p < 0.05) associated with plaque scores. Multivariate logistic regression analyses showed that rMSSD, but not sleep efficiency or AHI, was significantly associated with carotid plaque (OR 0.74, 95% CI 0.56-0.98, p = 0.037), independent of classical risk factors. The association of rMSSD with carotid plaque remained significant even after adjustment for sleep efficiency or AHI. A comparison of risk factors in specific subgroups showed that the association of lower HRV with carotid plaque was more prominent in patients with cardiovascular risk factors including male gender, hypertension, dyslipidemia and diabetes mellitus.

CONCLUSION

Cardiac autonomic nervous dysfunction was independently associated with carotid atherosclerosis, independent of sleep condition. Moreover, that association was more prominent in specific subgroups with cardiovascular risk factors.

Beneficial effects of low-dose aspirin on aortic stiffness in hypertensive patients

While treatment with low-dose aspirin has been established as a therapeutic tool for secondary prevention, the role of aspirin on primary prevention remains controversial. Aortic stiffness and wave reflections are independent predictors of cardiovascular events. The aim of the present study was to investigate the effect of low-dose aspirin on aortic stiffness and wave reflections in hypertensive patients. We studied 30 patients with grade I hypertension. Fifteen patients were treated with 160 mg of aspirin and 15 patients with placebo. Aortic stiffness and wave reflections were assessed by measuring carotid–femoral pulse wave velocity (PWV) and heart rate-adjusted augmentation index (AIx75), respectively. All measurements were conducted at baseline and 2 weeks after treatment. In the aspirin group, there was a significant reduction in PWV compared to the placebo group (from 8.9±1.5 to 8.5±1.6 m/s for the aspirin group vs from 8.6±1.4 to 8.7±1.6 m/s for the placebo group, net change: –0.5 m/s; p=0.02). AIx75 showed a marginal decrease (from 28.0±5.4 to 26.2±5.0% for the aspirin group vs from 31.2±9.7 to 30.6±9.2% for the placebo group, net change: –1.2%; p=0.06). In conclusion, a 2-week course of aspirin administration has a favorable effect on aortic stiffness and, to a lesser extent, on wave reflections in hypertensive patients. Whether the reduction in arterial stiffness is translated to fewer cardiovascular events needs to be confirmed by future prospective studies.

High platelet reactivity is associated with vascular function in patients after percutaneous coronary intervention receiving clopidogrel

BACKGROUND

In the present study, we evaluated the association of platelet reactivity with vascular function in patients after percutaneous coronary intervention receiving clopidogrel treatment.

METHODS

We enrolled 150 patients with stable CAD receiving clopidogrel regimen (75 mg/d), 1 month after percutaneous coronary intervention. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as an index of arterial wave reflections. High on treatment platelet reactivity (HPR) was evaluated using VerifyNow Assay. VerifyNow reports its results in P2Y12 reaction units (PRU), and the diagnostic cutoff value is 230 PRU. Patients were evaluated prospectively up to 24 months. The primary end point was a composite of death from cardiovascular causes, nonfatal major cardiovascular events and hospitalization for cardiovascular causes.

RESULTS

There was no difference in the basic clinical and demographic characteristics between subjects with HPR and non-HPR. Subjects with high on treatment platelet reactivity and PRU>230 had significantly increased PWV (8.81 ± 2.25 m/s vs. 7.69 ± 1.95 m/s, p = 0.001) and AIx (25.27 ± 8.67% vs. 20.87 ± 10.57%, p = 0.04) compared to subjects with PRU≤230. PWV was also associated with PRU (r = 0.23, p = 0.02). HPR was associated with significantly increased risk of primary end point [HR = 5.38, 95%CI:(1.15, 26.04), p = 0.03].

CONCLUSIONS

Increased platelet reactivity is associated with impaired arterial stiffness in patients after percutaneous coronary intervention receiving clopidogrel treatment, highlighting another clinical factor implicated in individual platelet response to antiplatelet therapy. Moreover, increased platelet reactivity is associated with adverse outcome in these patients.

Platelets and their chemokines in atherosclerosis-clinical applications

The concept of platelets as important players in the process of atherogenesis has become increasingly accepted due to accumulating experimental and clinical evidence. Despite the progress in understanding the molecular details of atherosclerosis, particularly by using animal models, the inflammatory and thrombotic roles of activated platelet s especially in the human system remain difficult to dissect, as often only the complications of atherosclerosis, i.e., stroke and myocardial infarction are definable but not the plaque burden. Platelet indices including platelet count and mean platelet volume (MPV) and soluble mediators released by activated platelets are associated with atherosclerosis. The chemokine CXCL4 has multiple atherogenic activities, e.g., altering the differentiation of T cells and macrophages by inhibiting neutrophil and monocyte apoptosis and by increasing the uptake of oxLDL and synergizing with CCL5. CCL5 is released and deposited on endothelium by activated platelets thereby triggering atherogenic monocyte recruitment, which can be attenuated by blocking the corresponding chemokine receptor CCR5. Atheroprotective and plaque stabilizing properties are attributed to CXCL12, which plays an important role in regenerative processes by attracting progenitor cells. Its release from luminal attached platelets accelerates endothelial healing after injury. Platelet surface molecules GPIIb/IIIa, GP1bα, P-selectin, JAM-A and the CD40/CD40L dyade are crucially involved in the interaction with endothelial cells, leukocytes and matrix molecules affecting atherogenesis. Beyond the effects on the arterial inflammatory infiltrate, platelets affect cholesterol metabolism by binding, modifying and endocytosing LDL particles via their scavenger receptors and contribute to the formation of lipid laden macrophages. Current medical therapies for the prevention of atherosclerotic therapies enable the elucidation of mechanisms linking platelets to inflammation and atherosclerosis.

Platelet activation: a link between psoriasis per se and subclinical atherosclerosis--a case-control study

BACKGROUND

Pathomechanisms of both psoriasis and atherosclerosis may involve platelet activation. Activated platelets show increased P-selectin; CD62 expression, and mean platelet volume (MPV). Impaired brachial artery flow-mediated dilatation (FMD) is related to atherosclerosis.

OBJECTIVES

To determine the presence of subclinical atherosclerosis in patients with psoriasis (without overt cardiovascular complications or traditional cardiovascular disease risk factors), compared with controls.

METHODS

In this case-control study, 25 patients with psoriasis and 25 age- and gender-matched healthy individuals were subjected to assessment of MPV, CD62 expression using flow cytometry, and brachial artery FMD and transthoracic echocardiography by cardiac ultrasound scanner.

RESULTS

A statistically highly significant increased CD62 expression, but not MPV, was found in cases compared with controls, and in patients with moderate/severe psoriasis compared with either mild cases or controls (P < 0.001). CD62 expression was statistically significantly positively correlated with the Psoriasis Area and Severity Index (PASI) score (P < 0.001), baseline brachial artery diameter (P = 0.03) but not FMD and aortic root diameter (ARD; P = 0.03). ARD was statistically significantly higher in patients with moderate/severe psoriasis compared with controls (P = 0.017). Stepwise simple linear regression analysis revealed that PASI score was the most important factor affecting CD62 expression (P < 0.001).

CONCLUSIONS

Our study showed increased atherosclerosis risk in patients with psoriasis, particularly those with moderate/severe disease, as evidenced by increased expression of platelet CD62 compared with healthy controls. Moreover, we found a positive correlation between CD62 expression and ARD (another possible marker of atherosclerosis), with positive correlation to the PASI score; the most important factor influencing CD62 expression. However, our data on MPV and FMD do not support the use of either value for diagnosing subclinical atherosclerosis in patients with psoriasis in further studies.

Predictors of epicardial adipose tissue in patients with type 2 diabetes mellitus

BACKGROUND

Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) were introduced as potential markers to determine inflammation in various disorders. Recently, atherogenic index of plasma (AIP) was found to be closely associated with atherosclerosis in general population. Waist circumference is commonly used to assess the risk factors in various metabolic disorders. There has been a well known relation between inflammation and peripheral adipose tissue in diabetes mellitus. However, the data regarding EAT and inflammation is scant in this population. Hence, we aimed to determine the relationship between PLR, NLR, AIP, waist circumference and EAT in diabetic patients.

METHODS

This was a cross-sectional study involving 156 patients with type 2 diabetes mellitus (87 females, 69 males; mean age, 53.62 ± 9.33 years) and 50 control subjects (35 females, 15 males; mean age, 51.06 ± 8.74 years). EAT was measured by using a trans-thoracic echocardiogram. Atherogenic index of plasma was calculated as the logarithmically transformed ratio of the serum triglyceride to high density lipoprotein (HDL)cholesterol. NLR and PLR were calculated as the ratio of the neutrophils and platelets to lymphocytes, respectively.

RESULTS

Waist circumference, PLR, NLR, AIP and EAT measurements were significantly higher in diabetic patients when compared to control subjects. When diabetic patients were separated into two groups according to their median value of EAT (Group 1, EAT < 4.53 (n = 78) and group 2, EAT ≥4.53 (n = 78)), group 2 patients had significantly higher Body mass index (BMI), waist circumference, AIP, NLR and PLR levels. In the bivariate correlation analysis, EAT was positively correlated with PLR, NLR, AIP, BMI and waist circumference (r = 0.197, p = 0.014; r = 0.229, p = 0.004; r = 0.161, p = 0.044; r = 0.248, p = 0.002; r = 0.306, p < 0.001, respectively). Waist circumference was found to be independent variables of EAT.

CONCLUSIONS

Simple calculation of PLR and measurement of waist circumference were found to be associated with increased EAT in diabetic patients.

Stroke with intracranial stenosis is associated with increased platelet activation in sickle cell anemia

BACKGROUND

Overt stroke in sickle cell anemia (SCA) is associated with intracranial stenosis and thrombus formation. Platelet activation is critical for thrombus formation.

PROCEDURE

Platelet activation studies were performed in 50 subjects: 18 SCA patients with history of stroke or abnormal transcranial Doppler (TCD) and intracranial stenosis seen by magnetic resonance angiogram (MRA), 7 SCA patients with history of stroke or abnormal TCD but no intracranial stenosis, 13 SCA patients with no history of stroke or abnormal TCD, and 12 healthy African-Americans.

RESULTS

Of the 18 patients with intracranial stenosis, 11 (61%) had evidence of the moyo-moya phenomenon on MRA. SCA children with intracranial stenosis had a significantly greater total white cell count compared to both healthy African-American controls and SCA patients in the steady-state (P < 0.001). In addition, SCA patients with history of stroke or abnormal TCD had a significantly higher platelet count compared to healthy African-American controls (P < 0.002). The percentage of platelet surface P-selectin expression was significantly greater in patients with intracranial stenosis compared to the other groups (P < 0.05), particularly in individuals that did not have the moya-moya phenomenon seen on MRA.

CONCLUSION

Stroke with intracranial stenosis is associated with increased platelet activation in sickle cell anemia, and further investigation is needed on the role of anti-platelet agents in this high-risk population.

Fibrinogen facilitates atherosclerotic formation in Sprague-Dawley rats: A rodent model of atherosclerosis

Fibrinogen (Fg) contributes to thrombosis and hemostasis and plays a role in inflammation. Fg is also known to play a significant role in atherosclerosis (AS). P-selectin has been associated with AS. The present study aimed to identify the role of Fg in AS and to examine the possible mechanisms behind the effects of fibrinogen on AS using Sprague-Dawley (SD) rats as a model system. Diet-induced atherosclerotic SD rats were adopted as the experimental models. Fg was transfused into these rats and the degree of atherosclerotic lesion development was compared with that of control rats. Blood was obtained from the common abdominal aorta and then the biochemical characteristics were measured and ELISA assays performed. The aortas were then carefully separated, removed and placed in 10% (w/v) neutral formalin for use at a later stage. The root of the aorta was cut and samples were washed, dehydrated, cleared, dipped in wax, embedded, sliced, coated, grilled and stained with HE. Pathological HE-stained sections were examined by light microscopic analysis and immunohistochemistry was performed for Fg and P-selectin on representative tissue sections. The Fg-transfused, high-fat diet-fed group developed atherosclerotic lesions more readily compared with the control group. Immunohistochemical analysis revealed that Fg expression was higher in the endarterium of the Fg-transfused, high-fat diet-fed rats. P-selectin expression was also found to be correlated with Fg expression. Fg actively promotes atherosclerotic lesion development; one possible mechanism behind this is the ability of Fg to enhance P-selectin expression, which is also able to facilitate the development of atherosclerotic lesions.

Platelet flow cytometry

Flow cytometry is a powerful and versatile tool which can be used to provide substantial phenotypic data on platelets by yielding quantitative information of their physical and antigenic properties. This includes surface expression of functional receptors, bound ligands, expression of granule components, interaction of platelets with other platelets via aggregation, or interaction with other blood components, such as leukocytes or the plasma coagulation system. Quantitative assessment of these parameters may facilitate the diagnosis of inherited or acquired platelet disorders, assist in the diagnosis of diseases associated with platelet activation, or assist in the monitoring of safety and efficacy of antiplatelet therapy.