RhoA/rho kinase pathway activation in age-associated endothelial cell dysfunction and thrombosis.

The small GTPase RhoA and the downstream Rho kinase (ROCK) regulate several cell functions and pathological processes in the vascular system that contribute to the age-dependent risk of cardiovascular disease, including endothelial dysfunction, excessive permeability, inflammation, impaired angiogenesis, abnormal vasoconstriction, decreased nitric oxide production and apoptosis. Frailty is a loss of physiological reserve and adaptive capacity with advanced age and is accompanied by a pro-inflammatory and pro-oxidative state that promotes vascular dysfunction and thrombosis. This review summarises the role of the RhoA/Rho kinase signalling pathway in endothelial dysfunction, the acquisition of the pro-thrombotic state and vascular ageing. We also discuss the possible role of RhoA/Rho kinase signalling as a promising therapeutic target for the prevention and treatment of age-related cardiovascular disease.

How Protein Depletion Balances Thrombosis and Bleeding Risk in the Context of Platelet's Activatory and Negative Signaling.

Platelets are small cell fragments that play a crucial role in hemostasis, requiring fast response times and fine signaling pathway regulation. For this regulation, platelets require a balance between two pathway types: the activatory and negative signaling pathways. Activatory signaling mediators are positive responses that enhance stimuli initiated by a receptor in the platelet membrane. Negative signaling regulates and controls the responses downstream of the same receptors to roll back or even avoid spontaneous thrombotic events. Several blood-related pathologies can be observed when these processes are unregulated, such as massive bleeding in activatory signaling inhibition or thrombotic events for negative signaling inhibition. The study of each protein and metabolite in isolation does not help to understand the role of the protein or how it can be contrasted; however, understanding the balance between active and negative signaling could help develop effective therapies to prevent thrombotic events and bleeding disorders.

Effect of frailty status on mortality risk among chilean community-dwelling older adults.

INTRODUCTION: The study of frailty and its effect on the risk of mortality in older people is of utmost importance, but understanding the critical factors is still limited. Our main objective was to analyze the association of frailty with all-cause mortality in a prospective community cohort of older people. METHODS: A five-year longitudinal follow-up study was conducted with 1,174 community-dwelling older adults (men and women≥65 years old) from different Family Health Centers and community groups from Chile. We evaluated the functional risk, socioeconomic status, and anthropometric variables. The frailty status was evaluated by modified Fried criteria. RESULTS: The diagnosis of frailty was reached in 290 older adult participants, who had significantly increased 5-year all-cause mortality independently of age, sex, cognitive impairment, and socioeconomic status (adjusted HR 1.51, 1.06-2.15). CONCLUSION: Frailty is a predictor of increased mortality independently of age, sex, socio-economic and cognitive factors.

Determination of the Bioactive Effect of Custard Apple By-Products by In Vitro Assays.

Annona cherimola fruit, known as cherimoya or custard apple, is an exotic fruit from South America but is strongly produced in Andalusia, Spain. Its by-products (seeds and peel) are recognised as important sources of antioxidants, including phenolic acids, flavonoids and procyanidins. Therefore, the aim of this study was to carry out the characterization of its phenolic composition and to in vitro evaluate the bioactivity of custard apple seed and peel. Therefore, high performance liquid chromatography coupled to mass spectrometry (HPLC-ESI-qTOF-MS) was performed in order to tentatively identify their phenolic composition. In the end, 19 compounds were identified and quantified, some of them for the first time in the custard apple matrix. Then, seed and peel total phenolic content, as well as antioxidant properties, radical scavenging capacity (O2, NO, HOCl) and inhibition of enzymes involved in different pathologies (hyaluronidase, elastase, collagenase, tyrosinase, acetylcholinesterase and xanthine oxidase), were evaluated. Although both extracts showed almost similar antioxidant capacities, custard apple seed stood out slightly more than peel (171 ± 2 vs. 130.0 ± 0.4 µmol TE/g DE, resp.), especially as ·NO scavenger (IC50 1.5 ± 0.2 vs. 11.8 ± 0.3 mg/L, resp.) and hyaluronidase inhibitor (IC50 170 ± 10 vs. 460 ± 20mg/L, resp.). Finally, the application of extracts on a real human model of platelet aggregation was performed, reporting antiaggregatory effects in agonist-promoted platelet thrombus formation. All these results show that custard apple by-products are stated as interesting sources of bioactive compounds with multiple industrial applications for the development of high-added-value products, such as functional foods, nutraceuticals and cosmeceuticals, promoting the circular bioeconomy of these by-products.

A Comprehensive Literature Review on Cardioprotective Effects of Bioactive Compounds Present in Fruits of Aristotelia chilensis Stuntz (Maqui).

Some fruits and vegetables, rich in bioactive compounds such as polyphenols, flavonoids, and anthocyanins, may inhibit platelet activation pathways and therefore reduce the risk of suffering from CVD when consumed regularly. Aristotelia chilensis Stuntz (Maqui) is a shrub or tree native to Chile with outstanding antioxidant activity, associated with its high content in anthocyanins, polyphenols, and flavonoids. Previous studies reveal different pharmacological properties for this berry, but its cardioprotective potential has been little studied. Despite having an abundant composition, and being rich in bioactive products with an antiplatelet role, there are few studies linking this berry with antiplatelet activity. This review summarizes and discusses relevant information on the cardioprotective potential of Maqui, based on its composition of bioactive compounds, mainly as a nutraceutical antiplatelet agent. Articles published between 2000 and 2022 in the following bibliographic databases were selected: PubMed, ScienceDirect, and Google Scholar. Our search revealed that Maqui is a promising cardiovascular target since extracts from this berry have direct effects on the reduction in cardiovascular risk factors (glucose index, obesity, diabetes, among others). Although studies on antiplatelet activity in this fruit are recent, its rich chemical composition clearly shows that the presence of chemical compounds (anthocyanins, flavonoids, phenolic acids, among others) with high antiplatelet potential can provide this berry with antiplatelet properties. These bioactive compounds have antiplatelet effects with multiple targets in the platelet, particularly, they have been related to the inhibition of thromboxane, thrombin, ADP, and GPVI receptors, or through the pathways by which these receptors stimulate platelet aggregation. Detailed studies are needed to clarify this gap in the literature, as well as to specifically evaluate the mechanism of action of Maqui extracts, due to the presence of phenolic compounds.

Frail older adults show a distinct plasma microvesicle profile suggesting a prothrombotic and proinflammatory phenotype.

In a global context of advanced aging, geriatric diseases such as frailty syndrome face challenges in the search for biomarkers and preventive strategies. Frailty has been associated with atherothrombotic pathologies. Circulating microvesicles (cMVs), phospholipid-rich vesicles with a size of 0.1-1.0 µm, have been shown to participate in atherothrombosis onset and progression. We have hypothesized that cMVs from platelets, and vascular and immune cells, are increased in frail older adults. To verify this, a prevalent-case control study was designed with 28 frail older and 27 nonfrail older adults older than 64 years. Frailty was defined by Fried's phenotype. Total cMVs, annexin V positive (AV+)-cMVs, and annexin V negative (AV- )-cMVs derived from blood and vascular cells were measured by flow cytometry. In the analysis of total cMVs, the frail group presented higher levels of CD14+ /CD142+ (p = .042), CD41a+ /CD142+ (p = .041), and CD56+ (p = .025), CD14+ cMVs (p = .043), and CD16+ /CD14+ (p = .019) cMVs levels. Within the phosphatidylserine-exposing cMVs (AV+ ), the frail group showed higher CD14+ /AV+ (p = .044), CD9+ /AV+ (p = .031), P2RY12+ /AV+ (p = .028), and CD235a+ /AV+ (p = .043) cMVs concentrations. Finally, within AV- cMVs, the frail group showed higher CD142+ /CD41a+ /AV- cMVs concentrations originated from platelets (p = .027), CD56+ /AV- originated from natural killer cells (p = .022), and CD34+ /AV- cMVs from hematopoietic stem cells (p = .037). In summary, frail older adults present higher concentrations of platelet-, leukocyte-, and hematopoietic cell-derived cMVs compared to robust age-matched older adults. These cMVs may be involved in the deregulation of the immune system, endothelial damage, and increased risk of thrombosis associated with frailty.

Effect of advanced glycation end products on platelet activation and aggregation: a comparative study of the role of glyoxal and methylglyoxal.

Advanced glycation end products (AGEs) arising from dietary intake have been associated with numerous chronic diseases including cardiovascular diseases. The interaction between platelets and AGEs has been proposed to play a role in the etiology of cardiovascular diseases. However, the effects of the interaction between platelets and Maillard reaction products generated from glyoxal (Gly) or methylglyoxal (MG) are poorly understood. In this work, the effects of AGEs generated by the reaction between Gly or MG with Lys or bovine serum albumin (BSA) on platelet activation and aggregation were assessed. AGEs were generated incubating Gly or MG with Lys or BSA during 5 hours or 14 days, respectively. AGEs generation were characterized by kinetic studies and by amino acid analysis. Human platelet-rich plasma (PRP) was incubated with different concentrations of AGEs from Lys-MG or Lys-Gly and BSA-MG or BSA-Gly. Platelet activation was determined quantifying the expression of CD62 (P-selectin) in PRP exposed to different AGEs concentrations. It was found that Lys-MG and Lys-Gly induced an increase in P-selectin expression (p < .05), being 33.9% higher for Lys-MG when compared to Lys-Gly. Platelets incubated in the presence of BSA-MG and BSA-Gly did not show an increase in the P-selectin expression. Platelet aggregation was significantly higher for the mixture Lys-MG (in all the range of concentrations evaluated), whereas for Lys-Gly it was only significant the highest concentration (Lys 168 µM/Gly 168 µM). It was observed a significant increase in platelet aggregation induced by ADP for samples BSA-Gly. AGEs formed with MG-Lys induce a higher activation and aggregation of platelets when compared to those formed from Gly-Lys.

Mitoquinone (MitoQ) Inhibits Platelet Activation Steps by Reducing ROS Levels.

Platelet activation plays a key role in cardiovascular diseases. The generation of mitochondrial reactive oxygen species (ROS) has been described as a critical step required for platelet activation. For this reason, it is necessary to find new molecules with antiplatelet activity and identify their mechanisms of action. Mitoquinone (MitoQ) is a mitochondria-targeted antioxidant that reduces mitochondrial overproduction of ROS. In this work, the antiplatelet effect of MitoQ through platelet adhesion and spreading, secretion, and aggregation was evaluated. Thus MitoQ, in a non-toxic effect, decreased platelet adhesion and spreading on collagen surface, and expression of P-selectin and CD63, and inhibited platelet aggregation induced by collagen, convulxin, thrombin receptor activator peptide-6 (TRAP-6), and phorbol 12-myristate 13-acetate (PMA). As an antiplatelet mechanism, we showed that MitoQ produced mitochondrial depolarization and decreased ATP secretion. Additionally, in platelets stimulated with antimycin A and collagen MitoQ significantly decreased ROS production. Our findings showed, for the first time, an antiplatelet effect of MitoQ that is probably associated with its mitochondrial antioxidant effect.

In Vitro Assay of Quinoa (Chenopodium quinoa Willd.) and Lupin (Lupinus spp.) Extracts on Human Platelet Aggregation.

Cardiovascular disease (CVD) is the leading cause of death throughout the world. A major risk factor for CVD is platelet aggregation. Various plant extracts exhibit anti-aggregatory action in vitro. The dietary intake of traditional plant crops such as quinoa (Chenopodium quinoa Willd) and lupin (Lupinus spp., Fabaceae family), highly recognized for their high nutritional value, is increasing worldwide. The aim of the study was to assay possible antiplatelet effects of quinoa and lupin bean extracts in vitro. The proximate chemical composition of quinoa grains and the three most widely known lupin cultivars: blue (L. angustifolius), yellow (L. luteus or mutabilis) and white (L. albus) grown in Chile were analyzed. The anti-aggregation activity of the ethanol extracts of the crops was assayed using flow cytometry in ADP-stimulated human platelets, and their inhibition of the maximal platelet aggregation was measured. All the lupin extracts exhibited a significant anti-aggregatory effect (p < 0.0001), while quinoa extracts did not exert this effect compared to control platelets. In conclusion, lupin beans extracts exhibited an anti-aggregatory effect on activated human platelets.

Lipid Metabolism and Signaling in Platelet Function.

Modern society has changed its diet composition, transitioning to a higher intake of saturated fat with a 50% increase of cardiovascular risk (CVD). Within the context of increased CVD, there is an induction of a prothrombotic phenotype mainly due to increased platelet reactivity as well as decreased platelet response to inhibitors. Platelets maintain haemostasis through both blood components and endothelial cells that secrete inhibitory or stimulatory molecules to regulate thrombus formation. There exist a correlation between platelets' polyunsaturated fatty acid (PUFA) and the increase in platelet reactivity. The aim of this chapter is to review the metabolism of the main PUFAs involved in platelet function associated with the role that their enzyme-derived oxidized metabolites exert in platelet function and fate. Finally, how lipid metabolism in the organism affect platelet aggregation and activation and the pharmacological modulation of these processes will also be discussed.

Roles of Phenolic Compounds in the Reduction of Risk Factors of Cardiovascular Diseases.

The population is now living longer during the period classified as "elderly" (60 years and older), exhibiting multimorbidity associated to the lengthening of the average life span. The dietary intake of phenolic compounds (PC) may affect the physiology, disease development and progression during the aging process, reducing risk factors of age related diseases. The aim of this review is to briefly describe some of the possible effects of a series of PC on the reduction of risk factors of the onset of cardiovascular diseases, considering their potential mechanisms of action. The main actions described for PC are associated with reduced platelet activity, anti-inflammatory effects, and the protection from oxidation to reduce LDL and the generation of advanced glycation end products. Preclinical and clinical evidence of the physiological effects of various PC is presented, as well as the health claims approved by regulatory agencies.

Natural Bioactive Compounds As Protectors Of Mitochondrial Dysfunction In Cardiovascular Diseases And Aging.

Diet, particularly the Mediterranean diet, has been considered as a protective factor against the development of cardiovascular diseases, the main cause of death in the world. Aging is one of the major risk factors for cardiovascular diseases, which have an oxidative pathophysiological component, being the mitochondria one of the key organelles in the regulation of oxidative stress. Certain natural bioactive compounds have the ability to regulate oxidative phosphorylation, the production of reactive oxygen species and the expression of mitochondrial proteins; but their efficacy within the mitochondrial physiopathology of cardiovascular diseases has not been clarified yet. The following review has the purpose of evaluating several natural compounds with evidence of mitochondrial effect in cardiovascular disease models, ascertaining the main cellular mechanisms and their potential use as functional foods for prevention of cardiovascular disease and healthy aging.

Adenosine A2A receptor agonists with potent antiplatelet activity.

Selected adenosine A2A receptor agonists (PSB-15826, PSB-12404, and PSB-16301) have been evaluated as new antiplatelet agents. In addition, radioligand-binding studies and receptor-docking experiments were performed in order to explain their differential biological effects on a molecular level. Among the tested adenosine derivatives, PSB-15826 was the most potent compound to inhibit platelet aggregation (EC50 0.32 ± 0.05 µmol/L) and platelet P-selectin cell-surface localization (EC50 0.062 ± 0.2 µmol/L), and to increase intraplatelets cAMP levels (EC50 0.24 ± 0.01 µmol/L). The compound was more active than CGS21680 (EC50 0.97±0.07 µmol/L) and equipotent to NECA (EC50 0.31 ± 0.05 µmol/L) in platelet aggregation induced by ADP. In contrast to the results from cAMP assays, Ki values determined in radioligand-binding studies were not predictive of the A2A agonists' antiplatelet activity. Docking studies revealed the key molecular determinants of this new family of adenosine A2A receptor agonists: differences in activities are related to π-stacking interactions between the ligands and the residue His264 in the extracellular loop of the adenosine A2A receptor which may result in increased residence times. In conclusion, these results provide an improved understanding of the requirements of antiplatelet adenosine A2A receptor agonists.

Antiplatelet effect of differentially charged PEGylated lipid-polymer nanoparticles.

PEGylated nanoparticles have been extensively investigated in different platforms for drug delivery. However, the physiological effects related to platelet activation, and the potential procoagulant activity which could lead to thrombosis and further cardiovascular diseases have not been widely examined. In this work, we studied the effect of differentially charged PEGylated lipid-polymer nanoparticles in the human platelet aggregation and activation by light transmission aggregometry and flow cytometry. PEGylated nanoparticles inhibited the platelet aggregation with a dose dependency (350, 700, and 1400µg/mL) in both ADP- and collagen-induced platelet aggregation, and P-selectin expression. Charged nanoparticles (anionic and cationic) presented higher inhibitions of the platelet aggregation compared to neutral nanoparticles, and particularly the cationic particles generated a slightly higher effect. The obtained results demonstrated the safety of the differentially charged PEGylated lipid-polymer nanoparticles, and their ability to inhibit the aggregation and activation of human platelets stimulated by two classic platelet activators.

Immune System Dysfunction in the Elderly.

Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.

Mechanisms of Endothelial Protection by Natural Bioactive Compounds from Fruit and Vegetables.

The endothelium is fundamental for the regulation of vascular tone and structure. Under disease conditions, including the presence of cardiovascular disease risk factors, the endothelium loses its protective role and becomes a proatherosclerotic structure. In this article we searched for strategies from PUBMED and Science Direct databases using the following key words: endothelium, natural bioactive compounds, polyphenols and cardiovascular diseases. The search was restricted to english language papers. Studies have identified the contribution of diet to the risk of developing cardiovascular diseases. In this context, high intakes of fruit and vegetables are associated with the decrease of cardiovascular diseases. Thus the most important fruit/vegetables and bioactive compounds to prevent endothelial diseases are berries, apples, virgin olive oil, tomatoes, soybeans, and polyphenols, carotenoids and unsaturated fatty acids, respectively. The bioactive compounds from fruit and vegetables provide endothelial protection through the following mechanisms: improved eNOS/NO bioavailability, attenuates oxidative stress, inhibited NF-κB pathway and decreased cell adhesion molecules expression. In this article natural bioactive compound mechanisms of endothelium protection are thoroughly reviewed.

Inhibitory effects of Cyperus digitatus extract on human platelet function in vitro.

The purpose of this research was to investigate the mechanisms of antiplatelet action of Cyperus digitatus. The antiplatelet action of C. digitatus was studied on platelet function: secretion, adhesion, aggregation, and sCD40L release. The platelet ATP secretion and aggregation were significantly inhibited by CDA (ethyl acetate extract) at 0.1 mg/ml and after the incubation of whole blood with CDA, the platelet coverage was inhibited by 96 ± 3% (p < 0.001). At the same concentration, CDA significantly decreased sCD40L levels. The mechanism of antiplatelet action of CDA could be by NF-κB inhibition and that is cAMP independent. In conclusion, C. digitatus extract may serve as a new source of antiplatelet agents for food and nutraceutical applications.

Strawberry extract presents antiplatelet activity by inhibition of inflammatory mediator of atherosclerosis (sP-selectin, sCD40L, RANTES, and IL-1ß) and thrombus formation.

Cardiovascular disease prevention is of high priority in developed countries. Healthy eating habits including the regular intake of an antithrombotic diet (fruit and vegetables) may contribute to prevention. Platelet function is a critical factor in arterial thrombosis and the effect strawberries have is still unclear. Therefore, the aim of this study was to systematically examine the action of strawberries in preventing platelet activation and thrombus formation. Strawberry extract concentration-dependently (0.1-1 mg/ml) inhibited platelet aggregation induced by ADP and arachidonic acid. At the same concentrations as strawberry inhibits platelet aggregation, it significantly decreased sP-selectin, sCD40L, RANTES, and IL-1ß levels. The strawberry may exert significant protective effects on thromboembolic-related disorders by inhibiting platelet aggregation. Also, this suggests that antithrombotic activity may have novel anti-inflammatory effects.

Aqueous Extract of Tomato (Solanum lycopersicum L.) and Ferulic Acid Reduce the Expression of TNF-α and IL-1ß in LPS-Activated Macrophages.

Acute inflammation is essential for defending the body against pathogens; however, when inflammation becomes chronic, it is harmful to the body and is part of the pathophysiology of various diseases such as Diabetes Mellitus type 2 (DM2) and Cardiovascular Disease (CVD) among others. In chronic inflammation macrophages play an important role, mainly through the secretion of proinflammatory cytokines such as Tumor necrosis factor (TNF)-α and Interleukin (IL)-1ß, explained in part by activation of the Toll-like receptor 4 (TLR4), a signaling pathway which culminates in the activation of Nuclear factor (NF)-κB, an important transcription factor in the expression of these proinflammatory genes. On the other hand, the benefits on health of a diet rich in fruit and vegetables are well described. In this work, the effects of aqueous extract of tomato and ferulic acid on the expression of proinflammatory cytokines in LPS activated monocyte-derived THP-1 macrophages were investigated. In addition, using Western blot, we investigated whether the inhibition was due to the interference on activation of NF-κB. We found that both the tomato extract and ferulic acid presented inhibitory activity on the expression of TNF-α and IL-1ß cytokine by inhibiting the activation of NF-κB. The current results suggest that tomatoes and ferulic acid may contribute to prevention of chronic inflammatory diseases.

Role of access to parks and markets with anthropometric measurements, biological markers, and a healthy lifestyle.

BACKGROUND: This study examined the association between access to urban green spaces and markets with anthropometric measurements, biological markers, sociodemographic, and healthy lifestyle. METHODS: Geographic information systems were used to establish a correlation between environmental features and cardiovascular risk parameters. A total number of 832 (age range 18-74 years) individuals were selected for this study. RESULTS: Body mass index was significantly and positively related to the distance to parks (ρ = 0.079, p < 0.05), but negatively related to the distance to markets (ρ = -0.125, p < 0.05). In addition, waist circumference was similar and positively related to distance to parks (ρ = 0.097, p < 0.05) and negatively related to distance to markets (ρ = -0.092, p < 0.05). With respect to biochemical parameters, when there was an increase in the distance to markets, high-density lipoprotein cholesterol increased and glycemia decreased. CONCLUSION: The results of this study suggest the importance of the role of environmental factors such as parks and markets in the development of cardiovascular risk.