Activated platelets and atherosclerosis

Vulnerable Atherosclerotic Plaque: Is There a Molecular Signature?

Atherosclerosis and its clinical manifestations, coronary and cerebral artery diseases, are the most common cause of death worldwide. The main pathophysiological mechanism for these complications is the rupture of vulnerable atherosclerotic plaques and subsequent thrombosis. Pathological studies of the vulnerable lesions showed that more frequently, plaques rich in lipids and with a high level of inflammation, responsible for mild or moderate stenosis, are more prone to rupture, leading to acute events. Identifying the vulnerable plaques helps to stratify patients at risk of developing acute vascular events. Traditional imaging methods based on plaque appearance and size are not reliable in prediction the risk of rupture. Intravascular imaging is a novel technique able to identify vulnerable lesions, but it is invasive and an operator-dependent technique. This review aims to summarize the current data from literature regarding the main biomarkers involved in the attempt to diagnose vulnerable atherosclerotic lesions. These biomarkers could be the base for risk stratification and development of the new therapeutic drugs in the treatment of patients with vulnerable atherosclerotic plaques.

Platelet count and clinical outcomes among ischemic stroke patients with endovascular thrombectomy in DIRECT-MT

OBJECTIVES

The prognostic role of baseline platelet count (PLT) in acute ischemic stroke patients with large vessel occlusion undergoing endovascular thrombectomy is unclear. Whether PLT modifies alteplase treatment effect on clinical outcome in those patients is also uncertain.

METHODS

We derived data from a multicenter randomized clinical trial (DIRECT-MT) comparing intravenous alteplase before endovascular treatment vs. endovascular treatment only. The 654 patients with available PLT data were included. Primary outcome was the ordinal modified Rankin Scale (mRS) score evaluated at 90 days. We also assessed various secondary and safety outcomes.

RESULTS

After adjusting for confounding factors, patients in the top tertile of PLT had a significantly lower risk of a worse shift in the distribution of mRS score (Odds Ratio: 0.671, 95% Confidence Interval: 0.473-0.953, p for trend=0.025), major disability and death (Odds Ratio: 0.617, 95% Confidence Interval: 0.393-0.97, p for trend=0.037) as well as death (Odds Ratio: 0.544, 95% Confidence Interval: 0.313-0.947, p for trend=0.031), respectively, compared with the bottom one. Among patients in the bottom tertile of PLT, combination therapy was associated with a better imaging outcome of eTICI score of 2b, 2c or 3 on final angiogram (Odds Ratio: 3.23, 95% Confidence Interval: 1.49-7.002) with a marginally significant interaction effect.

CONCLUSIONS

Participants with higher baseline PLT had a decreased risk of poor functional outcomes. Low baseline PLT modified alteplase treatment effect on the eTICI score on final angiogram. Combination therapy was beneficial for patients with low baseline PLT to have a better reperfusion status.

Platelets from patients with visceral obesity promote colon cancer growth

Several studies highlighted the importance of platelets in the tumor microenvironment due to their ability to interact with other cell types such as leukocytes, endothelial, stromal and cancer cells. Platelets can influence tumor development and metastasis formation through several processes consisting of the secretion of growth factors and cytokines and/or via direct interaction with cancer cells and endothelium. Patients with visceral obesity (VO) are susceptible to pro-thrombotic and pro-inflammatory states and to development of cancer, especially colon cancer. These findings provide us with the impetus to analyze the role of platelets isolated from VO patients in tumor growth and progression with the aim to explore a possible link between platelet activation, obesity and colon cancer. Here, using xenograft colon cancer models, we prove that platelets from patients with visceral obesity are able to strongly promote colon cancer growth. Then, sequencing platelet miRNome, we identify miR-19a as the highest expressed miRNA in obese subjects and prove that miR-19a is induced in colon cancer. Last, administration of miR-19a per se in the xenograft colon cancer model is able to promote colon cancer growth. We thus elect platelets with their specific miRNA abundance as important factors in the tumor promoting microenvironment of patients with visceral obesity.

Aspirin Colorectal Cancer Prevention in Lynch Syndrome: Recommendations in the Era of Precision Medicine

Cancer prevention in the era of precision medicine has to consider integrated therapeutic approaches. Therapeutic cancer prevention should be offered to selected cohorts with increased cancer risk. Undoubtedly, carriers of hereditary cancer syndromes have a well-defined high cancer risk. Lynch Syndrome is one of the most frequent hereditary syndromes; it is mainly associated with colorectal cancer (CRC). Nonsteroidal anti-inflammatory drugs and, in particular, aspirin use, has been associated with reduced CRC risk in several studies, initially with contradictory results; however, longer follow-up confirmed a reduced CRC incidence and mortality. The CAPP2 study recruited 861 Lynch syndrome participants randomly assigned to 600 mg of aspirin versus placebo. Like sporadic CRCs, a significant CRC risk reduction was seen after an extended follow-up, with a median treatment time that was relatively short (2 years). The ongoing CAPP3 will address whether lower doses are equally effective. Based on pharmacology and clinical data on sporadic CRCs, the preventive effect should also be obtained with low-dose aspirin. The leading international guidelines suggest discussing with Lynch syndrome carriers the possibility of using low-dose aspirin for CRC prevention. We aim systematically promote this intervention with all Lynch syndrome carriers.

Can various complete blood count parameters helpful in preoperative diagnosis of adnexal torsion?

OBJECTIVE

Adnexal torsion is an important gynecological emergency due to nonfrequent but possible adverse reproductive outcomes. There is no specific laboratory marker to support the preoperative diagnosis or that can be used clinically. The aim of this study was to investigate the diagnostic values of platelet, neutrophil, lymphocyte, and red cell markers as an early indicator of ovarian torsion.

METHODS

This retrospective study included 28 female patients who were treated surgically for adnexal torsion between August 2010 and July 2020, and 29 control group women. The demographic data and routine hematological values of patients were compared for adnexal torsion prediction.

RESULTS

There were no differences between the groups in terms of the platelet count, platelet distribution width, red cell distribution width, and mean platelet volume values, and there were no differences in the demographic data. Statistical differences were found among white blood cell, hemoglobin, hematocrit, neutrophil and lymphocyte counts, neutrophil/lymphocyte ratio, and platelet/lymphocyte ratio, and 81.5% sensitivity and 82.1% specificity were identified for neutrophil/lymphocyte ratio 2.45 (area under the curve AUC 0.892; 95%CI 0.808-0.975; p<0.001). Odds ratio for neutrophil/lymphocyte ratio was 2.62 (95%CI 0.861-7.940, p=0.029).

CONCLUSION

According to the regression analysis, neutrophil/lymphocyte ratio was found to be the most beneficial among all blood count parameters for the pre-diagnosis of AT.

The Neutrophil-to-Lymphocyte and Platelet-to-Lymphocyte Ratios Predict Reperfusion and Prognosis after Endovascular Treatment of Acute Ischemic Stroke

Background: Studies assessing the prognostic effect of inflammatory markers of blood cells on the outcomes of patients with acute ischemic stroke treated with endovascular treatment (EVT) are sparse. We evaluated whether the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) affect reperfusion status in patients receiving EVT. Methods: Using a multicenter registry database, 282 patients treated with EVT were enrolled in this study. The primary outcome measure was unsuccessful reperfusion rate after EVT defined by thrombolysis in cerebral infarction grades 0–2a. Logistic regression analysis was performed to analyze the association between NLR/PLR and unsuccessful reperfusion rate after EVT. Results: Both NLR and PLR were higher in the unsuccessful reperfusion group than in the successful reperfusion group (p < 0.001). Multivariate analysis showed that both NLR and PLR were significantly associated with unsuccessful reperfusion (adjusted odds ratio (95% confidence interval): 1.11 (1.04–1.19), PLR: 1.004 (1.001–1.01)). The receiver operating characteristic curve showed that the predictive ability of both NLR and PLR was close to good (area under the curve (AUC) of NLR: 0.63, 95% CI (0.54–0.72), p < 0.001; AUC of PLR: 0.65, 95% CI (0.57–0.73), p < 0.001). The cutoff values of NLR and PLR were 6.2 and 103.6 for unsuccessful reperfusion, respectively. Conclusion: Higher NLR and PLR were associated with unsuccessful reperfusion after EVT. The combined application of both biomarkers could be useful for predicting outcomes after EVT.

Gene Expression Profile in Different Age Groups and Its Association with Cognitive Function in Healthy Malay Adults in Malaysia

The mechanism of cognitive aging at the molecular level is complex and not well understood. Growing evidence suggests that cognitive differences might also be caused by ethnicity. Thus, this study aims to determine the gene expression changes associated with age-related cognitive decline among Malay adults in Malaysia. A cross-sectional study was conducted on 160 healthy Malay subjects, aged between 28 and 79, and recruited around Selangor and Klang Valley, Malaysia. Gene expression analysis was performed using a HumanHT-12v4.0 Expression BeadChip microarray kit. The top 20 differentially expressed genes at p < 0.05 and fold change (FC) = 1.2 showed that PAFAH1B3, HIST1H1E, KCNA3, TM7SF2, RGS1, and TGFBRAP1 were regulated with increased age. The gene set analysis suggests that the Malay adult's susceptibility to developing age-related cognitive decline might be due to the changes in gene expression patterns associated with inflammation, signal transduction, and metabolic pathway in the genetic network. It may, perhaps, have important implications for finding a biomarker for cognitive decline and offer molecular targets to achieve successful aging, mainly in the Malay population in Malaysia.

Molecular Biomarkers Associated with Early-Onset Symptomatic Intracranial Atherosclerosis

Purpose

Previous studies have shown a rising incidence of early-onset symptomatic intracranial atherosclerosis (sICAS), which has brought a severe economic burden to social development. This study aimed to evaluate the molecular biomarkers associated with early-onset sICAS and to seek possible intervention strategies for early prevention.

Patients and Methods

We consecutively recruited patients with sICAS and divided them into two groups based on age: early-onset sICAS group as age ≤60 years old and late-onset sICAS group as age >60 years old. We collected and compared the demographic data and laboratory results of each group. A bivariate logistic regression model was applied to evaluate the independent molecular biomarkers of early-onset sICAS.

Results

A total of 1007 subjects with sICAS were enrolled in this study, comprising 519 patients in the early-onset sICAS group and 488 patients in the late-onset sICAS group. Bivariate logistic regression analysis demonstrated an increased level of white blood cell, platelet, albumin globulin ratio, free triiodothyronine, and a decreased level of total bile acid, urea nitrogen, high-density lipoprotein, homocysteine, and fibrinogen in the early-onset sICAS group when compared to the late-onset group.

Conclusion

Our study showed the relevance between early sICAS and circulating levels of different molecular biomarkers. Detection of these related molecular biomarkers may provide a simple way for early sICAS preventions in the future.

Contrast-enhanced ultrasound molecular imaging of activated platelets in the progression of atherosclerosis using microbubbles bearing the von Willebrand factor A1 domain

Platelet-endothelial interactions have been linked to increased inflammatory activation and a prothrombotic state in atherosclerosis. The interaction between von Willebrand factor (vWF)-A1 domain and platelet glycoprotein (GP) Ib/IX plays a significant role in mediating the adhesion of platelets to the injured endothelium. In the present study, contrast-enhanced ultrasound (CEU) molecular imaging with microbubbles bearing the vWF-A1 domain was performed to non-invasively monitor activated platelets on the vascular endothelium in the procession of atherosclerosis. A targeted CEU contrast agent was prepared by attaching the vWF-A1 domain to the shell of microbubbles (Mb_A1). Rat isotype control antibody was used to produce control (Mb_ctrl) microbubbles. The binding of Mb_A1 and Mb_ctrl to activated platelets was assessed in in vitro flow chamber experiments. Apolipoprotein E (ApoE^-/-) deficient mice were studied as a model of atherosclerosis. At 8, 16 and 32 weeks of age, CEU molecular imaging of the proximal aorta with Mb_A1 and Mb_ctrl was performed and the imaging signals from microbubbles were quantified. Atherosclerotic lesion severity and platelets on the endothelial surface were assessed by histology and immunohistochemistry. In in vitro flow chamber studies, attachment of Mb_A1 to activated platelets on culture dishes was significantly greater than that of Mb_ctrl across a range of shear stresses (P<0.05). The attachment of Mb_ctrl was sparse and not related to the aggregated platelets. As lesion development progressed in the ApoE^-/- mice, molecular imaging of activated platelets demonstrated selective signal enhancement of Mb_A1 (P<0.05 vs. Mb_ctrl) at all ages. Selective signal enhancement from Mb_A1 increased from 8 to 32 weeks of age. Immunohistochemistry for GPIIb revealed the presence of platelets on the endothelial cell surface in each group of ApoE^-/- mice and that the degree of platelet deposits was age-dependent. The results of the present study indicated that non-invasive CEU molecular imaging with targeted microbubbles bearing the vWF-A1 domain could not only detect activated platelets on the vascular endothelium but also indicate lesion severity in atherosclerosis.

Multifunctional pathology-mapping theranostic nanoplatforms for US/MR imaging and ultrasound therapy of atherosclerosis

Atherosclerotic thrombosis is the leading cause of most life-threatening cardiovascular diseases (CVDs), particularly as a result of rupture or erosion of vulnerable plaques. Rupture or erosion-prone plaques are quite different in cellular composition and immunopathology, requiring different treatment strategies. The current imaging technology cannot distinguish the types of vulnerable plaques, and thus empirical treatment is still applied to all without a tailored and precise treatment. Herein, we propose a novel strategy called "Multifunctional Pathology-mapping Theranostic Nanoplatform (MPmTN)" for the tailored treatment of plaques based on the pathological classification. MPmTNs are made up of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), containing contrast imaging materials Fe₃O₄ and perfluoropentane (PFP), and coated with specific plaque-targeted peptides PP1 and cyclic RGD. The PFP encapsulated inside the MPmTN can undergo a phase change from nanodroplets to gas microbubbles under therapeutic ultrasound (TUS) exposure. The acoustic and biological effects induced by TUS and disruption of microbubbles may further promote therapeutic effects. Hypothetically, MPmTN NPs can target the rupture-prone plaque via the binding of PP1 to class A scavenger receptors (SR-A) on macrophages, induce the apoptosis due to TUS exposure and thus reduce the chronic soakage of inflammatory cells. The MPmTN NPs can also target the erosion-prone plaque through the binding of cRGD to glycoprotein (GP) IIb/IIIa on activated platelets and promote platelet disaggregation under TUS exposure. Therefore, MPmTNs may work as a multifunctional pathology-mapping therapeutic agent. Our in vitro results show that the MPmTN with PP1 and cRGD peptides had a high binding affinity both for activated macrophages and blood clots. Under TUS exposure, the MPmTN could effectively induce macrophage apoptosis, destroy thrombus and exhibit good imaging properties for ultrasound (US) and MRI. In apoE^-/- mice, MPmTNs can selectively accumulate at the plaque site and reduce the T₂-weighted signal. The apoptosis of macrophages and disaggregation of activated platelets on the plaques were also confirmed in vivo. In summary, this study provides a potential strategy for a tailored treatment of vulnerable plaques based on their pathological nature and a multimodal imaging tool for the risk stratification and assessment of therapeutic efficacy.

Targeting Platelet in Atherosclerosis Plaque Formation: Current Knowledge and Future Perspectives

Besides their role in hemostasis and thrombosis, it has become increasingly clear that platelets are also involved in many other pathological processes of the vascular system, such as atherosclerotic plaque formation. Atherosclerosis is a chronic vascular inflammatory disease, which preferentially develops at sites under disturbed blood flow with low speeds and chaotic directions. Hyperglycemia, hyperlipidemia, and hypertension are all risk factors for atherosclerosis. When the vascular microenvironment changes, platelets can respond quickly to interact with endothelial cells and leukocytes, participating in atherosclerosis. This review discusses the important roles of platelets in the plaque formation under pro-atherogenic factors. Specifically, we discussed the platelet behaviors under disturbed flow, hyperglycemia, and hyperlipidemia conditions. We also summarized the molecular mechanisms involved in vascular inflammation during atherogenesis based on platelet receptors and secretion of inflammatory factors. Finally, we highlighted the studies of platelet migration in atherogenesis. In general, we elaborated an atherogenic role of platelets and the aspects that should be further studied in the future.

Translational insight into prothrombotic state and hypercoagulation in nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an emerging and threatening pathological condition, ranging from fatty liver (FL) to chronic steatohepatitis (NASH), liver cirrhosis, and eventually to hepatocellular carcinoma (HCC). Recent findings suggest that patients with NAFLD have a higher risk of cardiovascular events and thromboembolism and that this risk is independent of metabolic diseases that are frequently associated with NAFLD, such as diabetes, hyperlipidaemia, and obesity. The vascular involvement of NAFLD might be considered its systemic burden, conditioning higher mortality in patients affected by the disease. These clinical findings suggested the existence of a prothrombotic state in NAFLD, which is partially unexplored and whose underlying mechanisms are to date not completely understood. Here, we review the mechanisms involved in the pathogenesis of the prothrombotic state in NAFLD across the progression from the healthy liver through the different stages of the disease. We focused on the possible role of several metabolic features of NAFLD possibly leading to hypercoagulation other than endothelial and platelet activation, such as insulin-resistance, nitric oxide production regulation, and gut microbiota homeostasis. Also, we analysed the involvement of plasminogen activator inhibitor-1 (PAI-1) and thromboinflammation taking place in NAFLD. Finally, we described factors striking a prothrombotic imbalance in NASH cirrhosis, with a particular focus on the pathogenesis of portal vein thrombosis.

The relationship between the platelet to leukocyte ratio and mechanical thrombectomy outcomes in acute ischemic stroke patients

BACKGROUND AND PURPOSE

The predictive effect of blood cell ratio on ischemic event has been widely confirmed. Whether PWR and PNR can assess the risk of endovascular treatment (EVT) is largely unclear. This study aimed to investigate the prognostic value of PNR and PWR in acute ischemic stroke patients treated with EVT.

METHODS

Poor functional outcome was defined as Modified Rankin Scale (mRS) of 3-6 at 3 months, Symptomatic intracranial hemorrhage (sICH) was diagnosed based on CT scan and classified according to the criterial of Heidelberg Bleeding Classification. Binary logistical regression was used to analyze the relationship of PWR, PNR with functional outcome and symptomatic intracranial hemorrhage (sICH).

RESULTS

Patients with good prognosis had higher PNR and PWR value (29 vs. 24, P=0.002) (22 vs. 19, P=0.009), a lower rate of sICH (2.9% vs. 24.9%, P<0.001). In model 1, the lower PNR significantly associated with poor functional outcome (OR, 0.48; 95% CI 0.26-0.88; P=0.018), and sICH (OR, 0.42; 95% CI 0.19-0.91; P=0.028). The lower PWR only significantly associated with poor prognosis (OR, 0.97; 95% CI 0.94-1.00; P=0.038), and had a trend relation with sICH (OR, 0.98; 95% CI 0.94-1.02; P=0.328). In model 2 lower PNR still significantly associated with poor functional outcome (OR, 0.53; 95% CI 0.29-0.99; P=0.047), but showed a trend for predicting sICH (OR, 0.56; 95% CI 0.25-1.25; P=0.158).

CONCLUSION

Platelet to leukocyte ratio may be use to assess the risk of functional outcome and sICH in patients with acute anterior circulation occlusion stroke undergoing endovascular treatment in real world China.

Frontiers in positron emission tomography imaging of the vulnerable atherosclerotic plaque

Rupture of vulnerable atherosclerotic plaques leading to an atherothrombotic event is the primary driver of myocardial infarction and stroke. The ability to detect non-invasively the presence and evolution of vulnerable plaques could have a huge impact on the future identification and management of atherosclerotic cardiovascular disease. Positron emission tomography (PET) imaging with an appropriate radiotracer has the potential to achieve this goal. This review will discuss the biological hallmarks of plaque vulnerability before going on to evaluate and to present PET imaging approaches which target these processes. The focus of this review will be on techniques beyond [18F]FDG imaging, some of which are clinically advanced, and others which are on the horizon. As inflammation is the primary driving force behind atherosclerotic plaque development, we will predominantly focus on approaches which either directly, or indirectly, target this process.

Platelet to lymphocyte ratio predicting 6-month primary patency of drug-coated balloon for femoropopliteal disease

Background

Inflammatory reaction is an essential factor in the occurrence, development and prognosis of femoropopliteal disease (FPD). The ratio of platelets to lymphocytes (PLR) is a new indicator reflecting platelet aggregation and burden of systemic inflammation. Our study is to explore the association between preoperative platelet-to-lymphocyte ratio (pre-PLR) and 6-month primary patency (PP) after drug-coated balloon (DCB) in FPD.

Methods

There were 70 patients who underwent DCB for FPD contained in the study. According to 6-month PP, patients were divided into group A (PP ≥6 months, n = 54) and group B (PP < 6 months, n = 16). Logistic regression analysis was used to identify potential predictors for 6-month PP after DCB in FPD. A receiver operating characteristic (ROC) curve analysis was used to identify the cut-off value of pre-PLR to predict 6-month PP.

Results

Logistic regression analysis showed that pre-PLR (OR: 1.008, 95% CI: 1.001–1.016, P = 0.031) and lesion length > 10 cm (OR: 4.305, 95% CI: 1.061–17.465, P = 0.041) were independently predictive for 6-month PP. The cutoff value of pre-PLR obtained from the ROC analysis was 127.35 to determine 6-month PP with the area of 0.839. Subgroup analysis was conducted based on the cutoff value of pre-PLR. The 6-month PP in the group of pre-PLR < 127.35 was higher than that of pre-PLR ≥ 127.35 group (p < 0.001).

Conclusions

The present study indicated that an elevated pre-PLR was an effective additional indicator for predicting early PP in FPD after DCB.

Evaluation of neutrophil extracellular traps as the circulating marker for patients with acute coronary syndrome and acute ischemic stroke

Introduction

Neutrophil extracellular traps (NETs) are known to be induced by various factors. In this study, we tried to identify circulating levels of NETs in patients with acute coronary syndrome (ACS) and acute ischemic stroke (AIS) and to confirm its suitability as a new circulating marker in their detection.

Methods

We prospectively enrolled 95 patients with a diagnosis of ACS (N = 37) or AIS (N = 58) in Dong‐A University Hospital, Busan, Korea. The control group was selected from healthy adults (N = 25) who visited the hospital for health screening. Circulating levels of NETs were evaluated by measuring plasma concentrations of double‐stranded DNA (dsDNA) and DNA‐histone complex.

Results

The concentrations of dsDNA were statistically higher in patients with ACS or AIS than those in the control group (both P < .001). In the univariable and multivariable analyses, statistically significant risk factors were troponin I (TnI) level and dsDNA concentration in the ACS group (P = .046 and P = .015, respectively) and only dsDNA concentration in the AIS group (P = .002). In the receiver operating characteristic curve analyses, the area under the curve values for TnI level and dsDNA concentration in the ACS group were 0.878 and 0.968, respectively, and the value for dsDNA concentration in the AIS group was 0.859.

Conclusions

In this study, it was confirmed that the circulating level of NETs was increased in patients with ACS and AIS at initial presentation. Findings in this study show that NETs could be used as a new circulating marker for the initial diagnosis of ACS or AIS.

Legumain is upregulated in acute cardiovascular events and associated with improved outcome - potentially related to anti-inflammatory effects on macrophages

BACKGROUND AND AIMS

We have previously found increased levels of the cysteine protease legumain in plasma and plaques from patients with carotid atherosclerosis. This study further investigated legumain during acute cardiovascular events.

METHODS

Circulating levels of legumain from patients and legumain released from platelets were assessed by enzyme-linked-immunosorbent assay. Quantitative PCR and immunoblotting were used to study expression, while localization was visualized by immunohistochemistry.

RESULTS

In the SUMMIT Malmö cohort (n = 339 with or without type 2 diabetes and/or cardiovascular disease [CVD], and 64 healthy controls), the levels of circulating legumain were associated with the presence of CVD in non-diabetics, with no relation to outcome. In symptomatic carotid plaques and in samples from both coronary and intracerebral thrombi obtained during acute cardiovascular events, legumain was co-localized with macrophages in the same regions as platelets. In vitro, legumain was shown to be present in and released from platelets upon activation. In addition, THP-1 macrophages exposed to releasate from activated platelets showed increased legumain expression. Interestingly, primary peripheral blood mononuclear cells stimulated with recombinant legumain promoted anti-inflammatory responses. Finally, in a STEMI population (POSTEMI; n = 272), patients had significantly higher circulating legumain before and immediately after percutaneous coronary intervention compared with healthy controls (n = 67), and high levels were associated with improved outcome.

CONCLUSIONS

Our data demonstrate for the first time that legumain is upregulated during acute cardiovascular events and is associated with improved outcome.

A Unique Formulation of Cardioprotective Bio-Actives: An Overview of Their Safety Profile

The burden of cardiovascular disease (CVD) remains high globally and in the United States despite the availability of pharmaceuticals aimed at its prevention and treatment. An invention by Summit Innovation Labs, which is a formula consisting of a unique blend of select polyphenols (i.e., curcumin, quercetin, resveratrol), vitamin K2 as menaquinone-7, and magnesium, was recently developed to modulate the impact of the specific drivers of CVD, namely, vascular calcification, oxidative stress, and chronic inflammation. The SIL formulation is a dietary supplement that was designed leveraging the more bioavailable forms of ingredients with poor absorption, such as curcumin and quercetin. Each ingredient within the SIL formulation has been shown to contribute to CVD risk reduction by moderating the effect of CVD triggers, thereby providing a holistic prevention strategy for CVD in the healthy population. This review focuses on recently published clinical data to support the safety profile of these ingredients following oral administration. The preponderance of clinical trial data reviewed support the overall safety of the bioactives when used singly or in combination. The most commonly reported adverse effects were generally mild dose-related gastrointestinal disturbances, which may be alleviated with diet in some cases. In light of these, we conclude that the combination of the ingredients in the SIL formulation is reasonably expected to be safe.

Indoor air pollution in rural north-east India: Elemental compositions, changes in haematological indices, oxidative stress and health risks

Chronic smoke exposure, emitted by biomass fuel burning leads to many diseases, which are originated due to oxidative stress. The present study investigated the levels of PM_2.5, PM₁₀ and PM_2.5 bound trace metals released during cooking with fuelwood and subsequent changes in haematological parameters along with oxidative stress in rural tribal women of northeast India exposed to wood smoke. The levels of PM_2.5, PM₁₀ and trace metals associated with PM_2.5 (nickel, cobalt, manganese, zinc, cadmium, lead and copper) were measured. In addition, blood samples were analyzed for concentrations of different blood related parameters (haemoglobin, platelet count, red blood cells and white blood cells) and levels of antioxidants (reduced glutathione, superoxide dismutase, and catalase). Plasma malondialdehyde (MDA) was measured as a biomarker of lipid peroxidation. Health risk assessment was done to assess the potential risk posed by inhalation of fine particles emitted from cooking with fuel wood. Levels of both PM_2.5 and PM₁₀ were higher in wood users compared to LPG users during cooking period (644.4 ± 368.3 µg/m³ vs 50 ± 23.8 µg/m³; 915 ± 441.3 µg/m³ vs 83.3 ± 33 µg/m³) and it exceeded the permissible limits of WHO. Levels of trace metals during the cooking period in fuel wood users were significantly higher than LPG users (p = 0.01). After controlling possible confounders, both platelet count and white blood cells (WBC) had a significant positive association with PM_2.5and PM₁₀. Similarly, haemoglobin had a negative association with both PM_2.5 and PM₁₀. Depleted levels of antioxidant enzymes and increase in lipid peroxidation (MDA) suggest a close association with pollutants released from wood smoke, indicating oxidative stress in women who used fuelwood for cooking. The total hazard quotient (HQ) of 0.11 was within the acceptable limit (i.e., 1.0). The total excess lifetime cancer risk (ELCR) was 5.4 × 10^-6 which is five times higher than the acceptable limit of 1.0 × 10^-6. Individual carcinogenic risk of Ni (2.3 × 10^-6) and Cd (3.1 × 10^-6) were also higher compared to acceptable limit. These results indicate that tribal women cooking with wood are at greater risk of developing cancer and also give support to the positive association between wood smoke and oxidative stress.

Early prediction of severity in acute ischemic stroke and transient ischemic attack using platelet parameters and neutrophil-to-lymphocyte ratio

BACKGROUND

It is still not easy to predict severity promptly in patients with acute ischemic stroke (AIS) and transient ischemic attack (TIA). We investigated that platelet parameters or combinations of them could be a useful tool for early prediction of severity of AIS and TIA at admission and after 3 months.

METHODS

We prospectively recruited 104 patients newly diagnosed with AIS and TIA. We investigated their neutrophil-to-lymphocyte ratio (NLR) and platelet parameters. According to the Modified Rankin Scale scores, the patients were divided into two groups.

RESULTS

In receiver operating characteristic (ROC) curve analyses, mean platelet volume (MPV), NLR/platelet count (PLT), MPV/PLT, MPV*NLR, and MPV*NLR/PLT showed statistically significant results in both at admission and after 3 months. Values of area under ROC curves for those tests at admission were 0.646, 0.697, 0.664, 0.708, and 0.722, respectively. Also, values after 3 months were 0.591, 0.661, 0.638, 0.662, and 0.689, respectively.

CONCLUSION

MPV*NLR/PLT could be used as a relatively good tool for predicting severity at the time of admission and after 3 months than other parameters or combinations of them. Further studies have to be carried out to investigate the best parameter for predicting the severity of AIS and TIA.

The isothiocyanate sulforaphane modulates platelet function and protects against cerebral thrombotic dysfunction

BACKGROUND AND PURPOSE

Platelet activation provides a critical link between inflammation and thrombosis. Sulforaphane (SFN), a naturally occurring isothiocyanate, has been shown to display both anti-inflammatory and anti-thrombotic actions in the systemic microvasculature. As inflammation promotes thrombosis and vice versa, in this study we investigated whether SFN is able to reduce inflammatory potentiation of thrombotic events, suppress platelet activation and thrombus formation in the cerebral microvasculature.

EXPERIMENTAL APPROACH

Thrombosis was induced in the murine brain using the light/dye-injury model, in conjunction with LPS treatment, with and without SFN treatment. In vitro and in vivo platelet assays (aggregation, flow and other functional tests) were also employed, using both human and murine platelets.

KEY RESULTS

SFN was found to reduce LPS-mediated enhancement of thrombus formation in the cerebral microcirculation. In tail-bleed experiments, LPS treatment prolonged bleeding time, and SFN treatment was found to protect against this LPS-induced derangement of platelet function. SFN inhibited collagen-mediated platelet aggregation in vitro and in vivo and the associated adhesion and impaired calcium signalling. Furthermore, glycoprotein VI was shown to be involved in the protective effects observed with SFN treatment.

CONCLUSIONS AND IMPLICATIONS

The data presented here provide evidence for the use of SFN in preventing stroke in selected high-risk patient cohorts.

Molecular Imaging of Vulnerable Atherosclerotic Plaques in Animal Models

Atherosclerosis is characterized by intimal plaques of the arterial vessels that develop slowly and, in some cases, may undergo spontaneous rupture with subsequent heart attack or stroke. Currently, noninvasive diagnostic tools are inadequate to screen atherosclerotic lesions at high risk of acute complications. Therefore, the attention of the scientific community has been focused on the use of molecular imaging for identifying vulnerable plaques. Genetically engineered murine models such as ApoE^−/− and ApoE^−/−Fbn1C1039G^+/− mice have been shown to be useful for testing new probes targeting biomarkers of relevant molecular processes for the characterization of vulnerable plaques, such as vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, intercellular adhesion molecule (ICAM)-1, P-selectin, and integrins, and for the potential development of translational tools to identify high-risk patients who could benefit from early therapeutic interventions. This review summarizes the main animal models of vulnerable plaques, with an emphasis on genetically altered mice, and the state-of-the-art preclinical molecular imaging strategies.

Medicinal Plants with Antiplatelet Activity

Blood platelets play an essential role in the hemostasis and wound-healing processes. However, platelet hyperactivity is associated to the development and the complications of several cardiovascular diseases. In this sense, the search for potent and safer antiplatelet agents is of great interest. This article provides an overview of experimental studies performed on medicinal plants with antiplatelet activity available through literature with particular emphasis on the bioactive constituents, the parts used, and the various platelet signaling pathways modulated by medicinal plants. From this review, it was suggested that medicinal plants with antiplatelet activity mainly belong to the family of Asteraceae, Rutaceae, Fabaceae, Lamiaceae, Zygophyllaceae, Rhamnaceae, Liliaceae, and Zingiberaceae. The antiplatelet effect is attributed to the presence of bioactive compounds such as polyphenols, flavonoids, coumarins, terpenoids, and other substances which correct platelet abnormalities by interfering with different platelet signalization pathways including inhibition of the ADP pathway, suppression of TXA2 formation, reduction of intracellular Ca(2+) mobilization, and phosphoinositide breakdown, among others. The identification and/or structure modification of the plant constituents and the understanding of their action mechanisms will be helpful in the development of new antiplatelet agents based on medicinal plants which could contribute to the prevention of thromboembolic-related disorders by inhibiting platelet aggregation. Copyright © 2016 John Wiley & Sons, Ltd.

Therapeutic Potential of Dietary Phenolic Acids

Although modern lifestyle has eased the quality of human life, this lifestyle's related patterns have imparted negative effects on health to acquire multiple diseases. Many synthetic drugs are invented during the last millennium but most if not all of them possess several side effects and proved to be costly. Convincing evidences have established the premise that the phytotherapeutic potential of natural compounds and need of search for novel drugs from natural sources are of high priority. Phenolic acids (PAs) are a class of secondary metabolites spread throughout the plant kingdom and generally involved in plethora of cellular processes involved in plant growth and reproduction and also produced as defense mechanism to sustain various environmental stresses. Extensive research on PAs strongly suggests that consumption of these compounds hold promise to offer protection against various ailments in humans. This paper focuses on the naturally derived PAs and summarizes the action mechanisms of these compounds during disease conditions. Based on the available information in the literature, it is suggested that use of PAs as drugs is very promising; however more research and clinical trials are necessary before these bioactive molecules can be made for treatment. Finally this review provides greater awareness of the promise that natural PAs hold for use in the disease prevention and therapy.

The Role of Circulating Platelets Microparticles and Platelet Parameters in Acute Ischemic Stroke Patients

BACKGROUND

Platelet activation and aggregation are critical in the pathogenesis of acute ischemic stroke (AIS). Circulating platelet microparticles (PMPs) and platelet parameters are biologic markers of platelet function in AIS patients; however, their associations with stroke subtypes and infarct volume remain unknown.

METHODS

We recruited 112 AIS patients including large-artery atherosclerosis (LAA) and small-artery occlusion [SAO] subtypes and 35 controls in this study. Blood samples were collected at admission and after antiplatelet therapy. The levels of circulating PMPs and platelet parameters (mean platelet volume [MPV], platelet count, plateletocrit, and platelet distribution width) were determined by flow cytometry and hematology analysis, respectively. Infarct volume was examined at admission by magnetic resonance imaging.

RESULTS

(1) The levels of circulating PMPs and MPV were significantly elevated in AIS patients compared with healthy controls; (2) the level of circulating PMPs, but not platelet parameters, was decreased after antiplatelet therapy in AIS patients; (3) the infarct volume in LAA subtype was larger than that in SAO subtype. Notably, circulating PMP level was positively correlated with the infarct volume in LAA subtype. No association with infarct volume in either AIS subtype was observed for platelet parameters; and (4) according to the regression analysis, circulating PMP was an independent risk factor for the infarct volume in pooled AIS patients after adjustments of other impact factors (hypertension and diabetes).

CONCLUSIONS

Our results suggest that circulating PMP level is associated with cerebral injury of AIS, which offers a novel evaluation parameter for AIS patients.

Detection of high-risk atherosclerotic plaques with ultrasound molecular imaging of glycoprotein IIb/IIIa receptor on activated platelets

Objective: Ultrasound molecular imaging (UMI) of glycoprotein (GP) IIb/IIIa receptor on activated platelets offers a unique means of identifying high-risk atherosclerosis. We hypothesized that contrast-enhanced ultrasound with microbubbles (MBs) targeted to GP IIb/IIIa could be used to detect and quantify activated platelets on the surface of advanced plaques.

Methods and Results: A mouse model of advanced atherosclerosis was generated by maintaining apolipoprotein E-deficient (ApoE^-/-) mice on a hypercholesterolemic diet (HCD). The three other experimental groups consisted of ApoE^-/- and wild-type (C57BL/6) mice fed a normal chow diet and C57BL/6 mice on an HCD diet. Plaque formation was confirmed by histological and immunohistochemical methods using light, fluorescence, and electron microscopy. Mice were injected with a lipid MB-conjugated cyclic Arg-Gly-Asp peptide or nonspecific control peptide, and the abdominal aorta was examined by UMI. The accumulation of GP IIb/IIIa and activated platelets on the surface of atherosclerotic plaques was highest in the ApoE^-/-+HCD group, followed by ApoE^-/-+chow, C57BL/6+HCD, and C57BL/6+chow groups (P<0.05). Notably, GP IIb/IIIa expression was associated with the vulnerability index and necrotic center/fiber cap ratio (P<0.05), and contrast video intensity from adhered cyclic Arg-Gly-Asp-modified MBs (MB-cRGDs) was correlated with GP IIb/IIIa expression on the plaque surface (P<0.05).

Conclusion: GP IIb/IIIa of activated platelets on the atherosclerotic endothelium is a biomarker for high-risk plaques that can be quantified by UMI using MB-cRGDs, providing a noninvasive means for detecting high-risk plaques and preventing acute cardiovascular events.

Pathophysiology of isoprostanes in the cardiovascular system: implications of isoprostane-mediated thromboxane A2 receptor activation

Isoprostanes are free radical-catalysed PG-like products of unsaturated fatty acids, such as arachidonic acid, which are widely recognized as reliable markers of systemic lipid peroxidation and oxidative stress in vivo. Moreover, activation of enzymes, such as COX-2, may contribute to isoprostane formation. Indeed, formation of isoprostanes is considerably increased in various diseases which have been linked to oxidative stress, such as cardiovascular disease (CVD), and may predict the atherosclerotic burden and the risk of cardiovascular complications in the latter patients. In addition, several isoprostanes may directly contribute to the functional consequences of oxidant stress via activation of the TxA2 prostanoid receptor (TP), for example, by affecting endothelial cell function and regeneration, vascular tone, haemostasis and ischaemia/reperfusion injury. In this context, experimental and clinical data suggest that selected isoprostanes may represent important alternative activators of the TP receptor when endogenous TxA2 levels are low, for example, in aspirin-treated individuals with CVD. In this review, we will summarize the current understanding of isoprostane formation, biochemistry and (patho) physiology in the cardiovascular context.

Platelet activating factors in depression and coronary artery disease: a potential biomarker related to inflammatory mechanisms and neurodegeneration

The persistence of a depressive episode in coronary artery disease (CAD) patients not only heightens the risk of acute ischemic events, but it is also associated with accelerated cognitive decline. Antidepressant interventions for depression in CAD have only modest effects and novel approaches are limited by a poor understanding of etiological mechanisms. This review proposes that the platelet activating factor (PAF) family of lipids might be associated with the persistence of a depressive episode and related neurodegenerative pathology in CAD due to their association with leading etiological mechanisms for depression in CAD such as inflammation, oxidative and nitrosative stress, vascular endothelial dysfunction, and platelet reactivity. The evidence implicating PAFs in CAD, vascular pathology, and neurodegenerative processes is also presented. We also propose future directions for the investigation of PAFs as mediators of persistent depression. In summary, PAFs are implicated in leading mechanisms associated with depression in CAD. PAFs may therefore be associated with the persistence of depression in CAD and related to neurodegenerative and cognitive sequelae.

Influence of mental stress on platelet bioactivity

It is well established that various mental stress conditions contribute, or at least influence, underlying pathophysiological mechanisms in somatic, as well as in psychiatric disorders; blood platelets are supposed to represent a possible link in this respect. The anculeated platelets are the smallest corpuscular elements circulating in the human blood. They display different serotonergic markers which seem to reflect the central nervous serotonin metabolism. They are known as main effectors in haematological processes but recent research highlights their role in the innate and adaptive immune system. Platelets are containing a multitude of pro-inflammatory and immune-modulatory bioactive compounds in their granules and are expressing immune-competent surface markers. Research gives hint that platelets activation and reactivity is increased by mental stress. This leads to enhanced cross talk with the immune system via paracrine secretion, receptor interaction and formation of platelet leucocyte-aggregates. Recently it has been demonstrated that the immune system can have a remarkable impact in the development of psychiatric disorders. Therefore platelets represent an interesting research area in psychiatry and their role as a possible biomarker has been investigated. We review the influence of mental stress on what is termed platelet bioactivity in this article, which subsumes the mainly immune-modulatory activity of platelets in healthy volunteers, elderly persons with chronic care-giving strain, patients with cardiovascular diseases who are prone to psychosocial stress, as well as in patients with posttraumatic stress disorder. Research data suggest that stress enhances platelet activity, reactivity and immune-modulatory capacities.

The role of mean platelet volume in predicting thrombotic events

Studies on platelet function have accelerated and gained popularity since the advent of novel treatment modalities and techniques on atherosclerotic vascular disease, such as antiplatelet drugs and stents. Today it is widely known that platelets exert a fundamental role in inflammation in addition to their long known role in homeostasis and thrombotic events. Interaction with endothelial cells and leukocytes mediates inflammation, contributes to atherogenesis and modulates immune activity. Platelet activation which is a central factor in many arterial disorders may be triggered by multiple pathways. Platelet activation is shown as forming a larger shape, aggregation and releasing various active contents. Mean platelet volume is a marker of platelet size, function and activation. Increased mean platelet volume is shown by active and large platelets that release more thromboxane A2 than smaller ones. The aim of this review is to determine whether early detection of platelet activation via increased mean platelet volume would help to recognize the pro-inflammatory state and administer appropriate and effective treatment properly. An easily detectable marker by using a prompt and functional technique would help our approach to inflammation caused by platelets.

Platelets and atherogenesis: Platelet anti-aggregation activity and endothelial protection from tomatoes (Solanum lycopersicum L.)

In recent years, it has been shown that platelets are not only involved in the arterial thrombotic process, but also that they play an active role in the inflammatory process of atherogenesis from the beginning. The interaction between platelets and endothelial cells occurs in two manners: activated platelets unite with intact endothelial cells, or platelets in resting adhere to activated endothelium. In this context, inhibition of the platelet function (adhesion/aggregation) could contribute to the prevention of atherothrombosis, the leading cause of cardiovascular morbidity. This can be achieved with antiplatelet agents. However, at the public health level, the level of primary prevention, a healthy diet has also been shown to exert beneficial effects. Among those elements of a healthy diet, the consumption of tomatoes (Solanum lycopersicum L.) stands out for its effect on platelet anti-aggregation activity and endothelial protection, which may be beneficial for cardiovascular health. This article briefly discusses the involvement of platelets in atherogenesis and the possible mechanisms of action provided by tomatoes for platelet anti-aggregation activity and endothelial protection.

Platelet activation in obesity and metabolic syndrome

Obesity is associated with increased cardiovascular disease. Metabolic syndrome (MS) identifies substantial additional cardiovascular risk beyond the individual risk factors, and is a powerful predictor of cardiovascular events even regardless of body mass index, thus suggesting a common downstream pathway conferring increased cardiovascular risk. Platelet hyper-reactivity/activation plays a central role to accelerate atherothrombosis and is the result of the interaction among the features clustering in obesity and MS: insulin resistance, inflammation, oxidative stress, endothelial dysfunction. Interestingly, the same pathogenic events largely account for the less-than-expected response to antiplatelet agents, namely low-dose aspirin. The proposed explanations for this phenomenon, besides underdosing of drug and/or reduced bioavailability, subsequent to excess of adipose tissue, include enhanced platelet turnover, leading to unacetylated COX-1 and COX-2 in newly formed platelets as a source of aspirin-escaping thromboxane formation; extraplatelet sources of thromboxane, driven by inflammatory triggers; and enhanced lipid peroxidation, activating platelets with a mechanism bypassing COX-1 acetylation or limiting COX-isozyme acetylation by aspirin. This review will address the complex interactions between platelets and the pathogenic events occurring in obesity and MS, trying to translate this body of mechanistic information into a clinically relevant read-out, in order to establish novel strategies in the prevention/treatment of atherothrombosis.

Chemical characterization of pro-inflammatory amyloid-beta peptides in human atherosclerotic lesions and platelets

Amyloid-β (Aβ) peptides are intimately involved in the inflammatory pathology of atherosclerotic vascular disease (AVD) and Alzheimer's disease (AD). Although substantial amounts of these peptides are produced in the periphery, their role and significance to vascular disease outside the brain requires further investigation. Amyloid-β peptides present in the walls of human aorta atherosclerotic lesions as well as activated and non-activated human platelets were isolated using sequential size-exclusion columns and HPLC reverse-phase methods. The Aβ peptide isolates were quantified by ELISA and structurally analyzed using MALDI-TOF mass spectrometry procedures. Our experiments revealed that both aorta and platelets contained Aβ peptides, predominately Aβ40. The source of the Aβ pool in aortic atherosclerosis lesions is probably the activated platelets and/or vascular wall cells expressing APP/PN2. Significant levels of Aβ42 are present in the plasma, suggesting that this reservoir makes a minor contribution to atherosclerotic plaques. Our data reveal that although aortic atherosclerosis and AD cerebrovascular amyloidosis exhibit clearly divergent end-stage manifestations, both vascular diseases share some key pathophysiological promoting elements and pathways. Whether they happen to be deposited in vessels of the central nervous system or atherosclerotic plaques in the periphery, Aβ peptides may promote and perhaps synergize chronic inflammatory processes which culminate in the degeneration, malfunction and ultimate destruction of arterial walls.

Anthocyanin extract from black rice significantly ameliorates platelet hyperactivity and hypertriglyceridemia in dyslipidemic rats induced by high fat diets

Our previous studies have demonstrated that anthocyanin extract from black rice (AEBR) inhibits atherosclerosis. Whether dietary AEBR supplementation can affect platelet function, an important factor in the pathogenesis of cardiovascular diseases, remains unclear. The aim of the present study is to explore the effects and mechanisms of dietary AEBR supplementation on platelet function and lipid profile in dyslipidemic rats. We demonstrated herein that thromboxane A(2), the thrombogenic ratio of thromboxane A₂ and prostacyclin, serum calmodulin, and soluble P-selectin were significantly decreased in rats fed a high fat diet supplemented with AEBR. AEBR supplementation also remarkably lowered serum triglyceride and raised hepatic CPT-1 mRNA expression. These findings suggest that dietary intake of AEBR reduces platelet hyperactivity, hypertriglyceridemia, and body weight gain, and facilitates in the maintenance of optimal platelet function in dyslipidemic rats induced by high fat diets.

Platelet activation as a marker of heart attack

A key component of the pathology of myocardial infarction (i.e. heart attack) is platelet-rich thrombosis within the coronary arteries. In many cases this occurs despite the use of anti-platelet drugs such as aspirin, and this, alongside other evidence, prompts the search for novel markers of platelet activity, such as levels of platelet product soluble P selectin in the plasma. However, by themselves, high levels of soluble P-selectin are of insufficient sensitivity and specificity to contribute to the management of the chest pain that may be a heart attack. Conversely, the current report shows that low levels of soluble P selectin contribute to the diagnosis of myocardial infarction because, as low levels are so rarely found in this condition, heart attack can be ruled out. If confirmed, this will be a major step forward in the management of acute chest pain.