Subacute administration of cilostazol modulates PLC-γ/PKC-α/p38/NF-kB pathway and plays vascular protective effects through eNOS activation in early stages of atherosclerosis development.

AIMS: Hypercholesterolemia is an important risk factor for development of cardiovascular disturbances, such as atherosclerosis, and its treatment remains challenging in modern medicine. Cilostazol is a selective inhibitor of phosphodiesterase 3 clinically prescribed for intermittent claudication treatment. Due to its pleiotropic properties, such as lipid lowering, anti-inflammatory, and antioxidant effects, the therapeutic repurposing of cilostazol has become a strategic approach for atherosclerosis treatment. This study aimed to investigate the effects of subacute administration of cilostazol on the aortas of hypercholesterolemic rats, focusing on the signaling pathways involved in these actions. MAIN METHODS: A murine model of hypercholesterolemia was employed to mimic the early stages of atherosclerosis development. Vascular reactivity assays were performed on thoracic aorta rings to assess the vascular response, as well as the non-invasive blood pressure was evaluated by plethysmography method. Pro-inflammatory markers and malondialdehyde (MDA) levels were measured to investigate the anti-inflammatory and antioxidant effects of cilostazol. Western Blot analysis was performed in aortas homogenates to evaluate the role of cilostazol on PLC-γ/PKC-α/p38-MAPK/IκB-α/NF-кB and PKA/eNOS/PKG pathways. KEY FINDINGS: The hypercholesterolemic diet induced the production of pro-inflammatory mediators such as TNF-α, TXB2, VCAM, and worsened vascular function, marked by increased contractile response, decreased maximum relaxation, and elevated systolic and diastolic blood pressure. Cilostazol seems to counteract the deleterious effects promoted by hypercholesterolemic diet, showing important anti-inflammatory and vasculoprotective properties possibly through the inhibition of the PLC-γ/PKC-α/p38-MAPK/IκB-α/NF-кB pathway and activation of the PKA/eNOS/PKG pathway. SIGNIFICANCE: Cilostazol suppressed hypercholesterolemia-induced vascular dysfunction and inflammation. Our data suggest the potential repurposing of cilostazol as a pharmacological treatment for atherosclerosis.

Reviewing Atrial Fibrillation Pathophysiology from a Network Medicine Perspective: The Relevance of Structural Remodeling, Inflammation, and the Immune System.

Atrial fibrillation (AF) is the most common type of sustained arrhythmia. The numerous gaps concerning the knowledge of its mechanism make improving clinical management difficult. As omics technologies allow more comprehensive insight into biology and disease at a molecular level, bioinformatics encompasses valuable tools for studying systems biology, as well as combining and modeling multi-omics data and networks. Network medicine is a subarea of network biology where disease traits are considered perturbations within the interactome. With this approach, potential disease drivers can be revealed, and the effect of drugs, novel or repurposed, used alone or in combination, may be studied. Thus, this work aims to review AF pathology from a network medicine perspective, helping researchers to comprehend the disease more deeply. Essential concepts involved in network medicine are highlighted, and specific research applying network medicine to study AF is discussed. Additionally, data integration through literature mining and bioinformatics tools, with network building, is exemplified. Together, all of the data show the substantial role of structural remodeling, the immune system, and inflammation in this disease etiology. Despite this, there are still gaps to be filled about AF.

Cilostazol attenuates cardiac oxidative stress and inflammation in hypercholesterolemic rats.

Atherosclerosis is a multifactorial chronic disease associated with pro-inflammatory and pro-oxidative cardiovascular states. Cilostazol, a selective phosphodiesterase 3 inhibitor (PDE3), is clinically used in the treatment of intermittent claudication and secondary prevention of cerebral infarction. The aim of this study was to evaluate the cardioprotective effects of cilostazol and the molecular mechanisms involved in hypercholesterolemic rats. Male Wistar rats were divided into four groups: control group (C) and control + cilostazol group (C+CILO), that were fed a standard chow diet, and hypercholesterolemic diet group (HCD) and HCD + cilostazol (HCD+CILO) that were fed a hypercholesterolemic diet. Cilostazol treatment started after 30 days for C+CILO and HCD+CILO groups. Animals were administered cilostazol once a day for 15 days. Subsequently, serum and left ventricles were extracted for evaluation of lipid profile, inflammatory, and oxidative biomarkers. The HCD group displayed increased serum lipid levels, inflammatory cytokines production, and cardiac NF-kB protein expression and decreased cardiac Nrf2-mediated antioxidant activity. Conversely, the cilostazol treatment improved all these cardiac deleterious effects, inhibiting NF-kB activation and subsequently decreasing inflammatory mediators, reestablishing the antioxidant properties through Nrf2-mediated pathway, including increased SOD, GPx, and catalase expression. Taken together, our results indicated that cilostazol protects hypercholesterolemia-induced cardiac damage by molecular mechanisms targeting the crosstalk between Nrf2 induction and NF-kB inhibition in the heart.

Evaluation of the effects produced by subacute tributyltin administration on vascular reactivity of male wistar rats.

Tributyltin chloride (TBT) is an organotin compound widely used in several high biocides for agroindustrial applications, such as fungicides, and marine antifouling paints leading to endocrine disrupting actions, such as imposex development in mollusks. In female rats, TBT has been shown to promote ovarian dysfunction, reduction of estrogen protective effect in the vascular morphophysiology, at least in part by oxidative stress consequences. Estrogen causes coronary endothelium-dependent and independent vasodilation. However, the TBT effects on cardiovascular system of male rats are not fully understood. The aim of this study was to evaluate the effects of subacute TBT exposure in aorta vascular reactivity from male wistar rats. Rats were randomly divided into three groups: control (C), TBT 500 ng/kg/day and TBT 1000 ng/kg/day. TBT was administered daily for 30 days by oral gavage. We found that TBT exposure enhanced testosterone serum levels and it was also observed obesogenic properties. TBT exposure evoked an increase in endothelium-dependent and independent phenylephrine-induced contraction, associated to an inhibition in eNOS activity. On the other hand, it was observed an enhancement of iNOS and NF-kB protein expression. We also observed an increase in oxidative stress parameters, such as superoxide dismutase (SOD) and catalase expression, and also an increase in malondialdehyde production. Finally, TBT exposure produced aortic intima-media thickness. Taken together, these data suggest a potential cardiovascular toxicological effect after subacute TBT exposure in male rats.

Effects of Chloroquine and Hydroxychloroquine on the Cardiovascular System - Limitations for Use in the Treatment of COVID-19

Abstract Chloroquine (CQ) and Hydroxychloroquine (HCQ) are antimalarial drugs, with anti-inflammatory properties that justify their use in the treatment of systemic lupus erythematosus and rheumatic diseases. A pandemic caused by the new coronavirus led the entire world's scientific community to look for drugs already available on the market, capable of exercising beneficial actions in the fight against the disease. Preliminary studies in patients, as well as in vitro studies, suggested possible therapeutic effects associated with the use of HCQ and CQ in the treatment of COVID-19. Despite controversies over the effects of these drugs in combating the "cytokine storm" associated with COVID and the dismal of results in different clinical trials in Brazil, their use has been encouraged and several ongoing investigative studies are underway. In addition to the possible beneficial effects on the prognosis of patients with SARS-CoV-2, such drugs include varied effects on the cardiovascular system, ranging from positive developments related to their vasodilator properties to potential negative effects, such as cardiotoxicity. This work presents the main effects exerted by these drugs on the cardiovascular system, in order to contribute to a scientific discussion about the repurposing of these drugs in the context of COVID-19.

Could cilostazol be beneficial in COVID-19 treatment? Thinking about phosphodiesterase-3 as a therapeutic target.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) that has emerged and rapidly spread across the world. The COVID-19 severity is associated to viral pneumonia with additional extrapulmonary complications. Hyperinflammation, dysfunctional immune response and hypercoagulability state are associated to poor prognosis. Therefore, the repositioning of multi-target drugs to control the hyperinflammation represents an important challenge for the scientific community. Cilostazol, a selective phosphodiesterase type-3 inhibitor (PDE-3), is an antiplatelet and vasodilator drug, that presents a range of pleiotropic effects, such as antiapoptotic, anti-inflammatory, antioxidant, and cardioprotective activities. Cilostazol also can inhibit the adenosine uptake, which enhances intracellular cAMP levels. In the lungs, elevated cAMP promotes anti-fibrotic, vasodilator, antiproliferative effects, as well as mitigating inflammatory events. Interestingly, a recent study evaluated antiplatelet FDA-approved drugs through molecular docking-based virtual screening on viral target proteins. This study revealed that cilostazol is a promising drug against COVID-19 by inhibiting both main protease (Mpro) and Spike glycoprotein, reinforcing its use as a promising therapeutic approach for COVID-19. Considering the complexity associated to COVID-19 pathophysiology and observing its main mechanisms, this article raises the hypothesis that cilostazol may act on important targets in development of the disease. This review highlights the importance of drug repurposing to address such an urgent clinical demand safely, effectively and at low cost, reinforcing the main pharmacological actions, to support the hypothesis that a multi-target drug such as cilostazol could play an important role in the treatment of COVID-19.

Cilostazol exerts antiplatelet and anti-inflammatory effects through AMPK activation and NF-kB inhibition on hypercholesterolemic rats.

This work presents a model of rats fed a high-cholesterol diet, receiving a long-term oral administration of cilostazol, a PDE3-inhibitor. The aim of this study was to evaluate the molecular mechanisms by which cilostazol interferes with platelets signaling pathways to avoid atherosclerosis early development. Male Wistar rats were divided into 3 groups: Control group received standard rat chow (C), hypercholesterolemic group (HCD), and HCD+CIL (cilostazol group) received hypercholesterolemic diet for 45 days. HCD+CIL group received cilostazol (30 mg/kg/p.o.) once daily in the last 15 days. Platelet aggregation, lipid profile, lipid peroxidation, and cytokine serum levels were assessed. Expression of P-selectin, CD40L, PKC-α, IkB-α, and iNOS and activation of AMPK, NF-κB, and eNOS in the platelets were assessed using Western blot analysis. Cilostazol reduced the levels of total cholesterol (361.0 ± 12.8 vs. 111.5 ± 1.6 mg/dL), triglycerides (186.9 ± 17.7 vs. 55.4 ±3.1 mg/dL), cLDL (330.9 ± 9.7 vs. 61.5 ± 3.5 mg/dL), cVLDL (45.0 ± 4.6 vs. 11.1 ± 0.6 mg/dL), and malondialdehyde (9.4 ± 0.5 vs. 3.2 ± 0.3 nmol/mL) compared to the HCD group. Cilostazol presented antiplatelet properties and decreased inflammatory markers levels. These effects seem to be related to AMPK activation, NF-kB inhibition, and eNOS activation.

Anti-atherogenic effects of a new thienylacylhydrazone derivative, LASSBio-788, in rats fed a hypercholesterolemic diet.

The compound LASSBio-788 (N-Allyl (2-thienylidene) 3,4-methylenedioxybenzoylhydrazine) is a thienylacylhydrazone derivative shown to have antiplatelet, vasodilatory, and anti-inflammatory properties in vitro. We hypothesize that LASSBio-788 may exert beneficial effects on atherosclerosis. Male wistar rats were divided into 4 groups: Control group received standard rat chow, hypercholesterolemic group (HC) and HC+788 (compound LASSBio-788 group) received hypercholesterolemic diet for 45 days. HC+788 group received compound LASSBio-788 (100 µmol/kg) once daily in the last 15 days. LASSBio-788 reduced the levels of total cholesterol (109.1 ± 4.3 vs. 361.0 ± 12.8 mg/dl), triglycerides (66.1 ± 1.1 vs. 186.9 ± 17.7 mg/dl), LDLc (63.2 ± 6.1 vs. 330.9 ± 9.7 mg/dl), VLDLc (9.8 ± 1.1 vs. 45.0 ± 4.6 mg/dl) and malondialdehyde (4.8 ± 0.3 vs. 9.4 ± 0.5 nmol/ml) compared to the HC group. LASSBio-788 presented antiplatelet properties and decreased inflammatory markers levels. LASSBio-788 promoted a decrease in contractile response to phenylephrine and an improvement in endothelium-dependent vasorelaxant response by increasing two-fold the expression of nitric oxide synthase (eNOS). Our results suggest that the compound LASSBio-788 represents a new multi-targeted drug candidate for the treatment of atherosclerosis.

Inflamação e aterosclerose: novos biomarcadores e perspectivas terapêutica / Inflammation and atherosclerosis: new biomakers and outlooks for treatment

Atualmente a aterosclerose é considerada uma doença inflamatória crônica, provavelmente iniciada por disfunção endotelial associada a fatores inerentes à ativação do sistema imunológico. A disfunção endotelial pode ser causada por diversos fatores, como colesterol alto, presença de radicais livres, associada a fatores externos, hipertensão, diabetes mellitus, alterações genéticas, dentre outros. No local onde o endotélio se torna disfuncional ocorre uma resposta inflamatória, que estimula a migração e a proliferação de células musculares lisas, que se agregam à área de inflamação, formando uma lesão mais complexa. Além disso, ocorre o recrutamento de leucócitos e adesão de plaquetas ao endotélio na região da placa de ateroma. Apesar da indubitável utilidade do perfil lipídico na avaliação do risco aterosclerótico, esse dado fornece um panorama incompleto do paciente, uma vez que vários eventos cardiovasculares ocorrem em indivíduos com concentrações plasmáticas de colesterol e LDL consideradas adequadas. Considerando o papel de destaque dado ao processo inflamatório no desenvolvimento da aterosclerose, se faz necessária a observação de novos biomarcadores para uma melhor previsão de risco cardiovascular. Este trabalho resume aspectos importantes relacionados às metaloproteinases (MMP), proteína C-reativa (PCR), moléculas de adesão, TNF-α, interleucinas (IL) e adiponectina. O conhecimento destes possíveis marcadores constitui-se de vital importância para o direcionamento eficiente de novas abordagens terapêuticas, representando um novo horizonte no tratamento da aterosclerose.

Atherosclerosis is currently considered as a chronic inflammatory disease, probably caused by an endothelial dysfunction associated with factors inherent to the activation of the immune system. Endothelial dysfunction may be caused by several factors such as high cholesterol, free radicals, associated with external factors, hypertension, diabetes mellitus, genetic disorders and others. An inflammatory response occurs at the location where the endothelium becomes dysfunctional, stimulating the migration and proliferation of smooth muscle cells, clumping in the inflammation area and forming a more complex lesion, together with the recruitment of leukocytes and platelet adhesion to the endothelium in the atheromatous plaque region. Despite the undoubted utility of the lipid profile in atherosclerotic risk assessment, these data provide an incomplete overview of the patient, as many cardiovascular events occur in patients with cholesterol and LDL plasma concentrations rated as adequate. Considering the prominent role assigned to the inflammatory process for the development of atherosclerosis, it is necessary to observe new biomarkers in order to predict cardiovascular risk more effectively. This paper summarizes important aspects related to matrix metalloproteinases (MMPs), C-reactive protein (CRP), adhesion molecules, TNF-α, interleukins (ILs) and adiponectin. Knowledge of these potential markers is of vital importance for efficiently targeting new therapeutic approaches, opening up a new horizon for atherosclerosis treatment.

Aspectos farmacogenéticos associados à resistência terapêutica antiplaquetária em pacientes com síndrome coronariana aguda / Pharmacogenetic aspects associated with anti-platelet therapy resistance in patients with acute coronary syndrome

O uso de medicamentos que inibem a função plaquetária reduz significativamente as complicações isquêmicas com síndromes coronarianas agudas (SCA) e naqueles submetidos à intervenção coronariana percutânea (ICP) com stent. Apesar de toda a evoluçao da terapêutica antiplaquetária, os fenômenos trombóticos continuam a ocorrer e, embora suas causas determinantes sejam múltiplas, cresce o conceito de resistência terapêutica antiplaquetária, melhor entendida como a baixa resposta ou mesmo a ausência desta ao uso dos antiplaquetários, que pode refletir aspectos farmacológicos e farmacocinéticos de cada medicamento. A resistência antiplaquetária pode ser classificada em laboratórial ou clínica. A resistência laboratorial é definida como a falha do medicamento em inibir a função plaquetária ex vivo. A resistência clínica é definida como a falha do medicamento em prevenir a ocorrência de eventos adversos cardiovasculares em pacientes com SCA e em pacientes submetidos à ICP. Considerável variabilidade interindividual é observada nas respostas evocadas pelos diferentes inibidores de função plaquetária. Essa variabilidade está associada à elevada taxa de eventos adversos cardiovasculares. Parte dessa heterogeneidade é explicada por polimorfismos genéticos...