PURPL and NEAT1 Long Non-Coding RNAs Are Modulated in Vascular Smooth Muscle Cell Replicative Senescence

Cellular senescence is characterized by proliferation and migration exhaustion, senescence-associated secretory phenotype (SASP), and oxidative stress. Senescent vascular smooth muscle cells (VSMCs) contribute to cardiovascular diseases and atherosclerotic plaque instability. Since there are no unanimously agreed senescence markers in human VSMCs, to improve our knowledge, we looked for new possible senescence markers. To this end, we first established and characterized a model of replicative senescence (RS) in human aortic VSMCs. Old cells displayed several established senescence-associated markers. They stained positive for the senescence-associated β-galactosidase, showed a deranged proliferation rate, a dramatically reduced expression of PCNA, an altered migratory activity, increased levels of TP53 and cell-cycle inhibitors p21/p16, and accumulated in the G1 phase. Old cells showed an altered cellular and nuclear morphology, downregulation of the expression of LMNB1 and HMGB1, and increased expression of SASP molecules (IL1β, IL6, IL8, and MMP3). In these senescent VSMCs, among a set of 12 manually selected long non-coding RNAs (lncRNAs), we detected significant upregulation of PURPL and NEAT1. We observed also, for the first time, increased levels of RRAD mRNA. The detection of modulated levels of RRAD, PURPL, and NEAT1 during VSMC senescence could be helpful for future studies on potential anti-aging factors.

Lost in HELLS: Disentangling the mystery of SALNR existence in senescence cellular models

Long non-coding RNAs (lncRNAs) have emerged as key regulators of cellular senescence by transcriptionally and post-transcriptionally modulating the expression of many important genes involved in senescence-associated pathways and processes. Among the different lncRNAs associated to senescence, Senescence Associated Long Non-coding RNA (SALNR) was found to be down-regulated in different cellular models of senescence. Since its release in 2015, SALNR has not been annotated in any database or public repository, and no other experimental data have been published. The SALNR sequence is located on the long arm of chromosome 10, at band 10q23.33, and it overlaps the 3' end of the HELLS gene. This investigation helped to unravel the mystery of the existence of SALNR by analyzing publicly available short- and long-read RNA sequencing data sets and RT-PCR analysis in human tissues and cell lines. Additionally, the expression of HELLS has been studied in cellular models of replicative senescence, both in silico and in vitro. Our findings, while not supporting the actual existence of SALNR as an independent transcript in the analyzed experimental models, demonstrate the expression of a predicted HELLS isoform entirely covering the SALNR genomic region. Furthermore, we observed a strong down-regulation of HELLS in senescent cells versus proliferating cells, supporting its role in the senescence and aging process.

Smooth Muscle Cell Phenotypic Switch Induced by Traditional Cigarette Smoke Condensate: A Holistic Overview

Cigarette smoke (CS) is a risk factor for inflammatory diseases, such as atherosclerosis. CS condensate (CSC) contains lipophilic components that may represent a systemic cardiac risk factor. To better understand CSC effects, we incubated mouse and human aortic smooth muscle cells (SMCs) with CSC. We evaluated specific markers for contractile [i.e., actin, aortic smooth muscle (ACTA2), calponin-1 (CNN1), the Kruppel-like factor 4 (KLF4), and myocardin (MYOCD) genes] and inflammatory [i.e., IL-1β, and IL-6, IL-8, and galectin-3 (LGALS-3) genes] phenotypes. CSC increased the expression of inflammatory markers and reduced the contractile ones in both cell types, with KLF4 modulating the SMC phenotypic switch. Next, we performed a mass spectrometry-based differential proteomic approach on human SMCs and could show 11 proteins were significantly affected by exposition to CSC (FC ≥ 2.7, p ≤ 0.05). These proteins are active in signaling pathways related to expression of pro-inflammatory cytokines and IFN, inflammasome assembly and activation, cytoskeleton regulation and SMC contraction, mitochondrial integrity and cellular response to oxidative stress, proteostasis control via ubiquitination, and cell proliferation and epithelial-to-mesenchymal transition. Through specific bioinformatics resources, we showed their tight functional correlation in a close interaction niche mainly orchestrated by the interferon-induced double-stranded RNA-activated protein kinase (alternative name: protein kinase RNA-activated; PKR) (EIF2AK2/PKR). Finally, by combining gene expression and protein abundance data we obtained a hybrid network showing reciprocal integration of the CSC-deregulated factors and indicating KLF4 and PKR as the most relevant factors.

Caffeic Acid-Grafted PLGA as a Novel Material for the Design of Fluvastatin-Eluting Nanoparticles for the Prevention of Neointimal Hyperplasia

Drug-eluting nanoparticles (NPs) administered by an eluting balloon represent a novel tool to prevent restenosis after angioplasty, even if the selection of the suitable drug and biodegradable material is still a matter of debate. Herein, we provide the proof of concept of the use of a novel material obtained by combining the grafting of caffeic acid or resveratrol on a poly(lactide-co-glycolide) backbone (g-CA-PLGA or g-RV-PLGA) and the pleiotropic effects of fluvastatin chosen because of its low lipophilic profile which is challenging for the encapsulation in NPs and delivery to the artery wall cells. NPs made of such materials are biocompatible with macrophages, human smooth muscle cells (SMCs), and endothelial cells (ECs). Their cellular uptake is demonstrated and quantified by confocal microscopy using fluorescent NPs, while their distribution in the cytoplasm is verified by TEM images using NPs stained with an Ag-PVP probe appositely synthetized. g-CA-PLGA assures the best control of the FLV release from NP sizing around 180 nm and the faster SMC uptake, as demonstrated by confocal analyses. Interestingly and surprisingly, g-CA-PLGA improves the FLV efficacy to inhibit the SMC migration, without altering its effects on EC proliferation and migration. The improved trophism of NPs toward SMCs, combined with the excellent biocompatibility and low modification of the microenvironment pH upon polymer degradation, makes g-CA-PLGA a suitable material for the design of drug-eluting balloons.

Artichoke and bergamot extracts: a new opportunity for the management of dyslipidemia and related risk factors

The relationship between low LDL-C (cholesterol associated with low-density lipoprotein) and a lower relative risk of developing cardiovascular disease (CVD) has been widely demonstrated. Although from a pharmacological point of view, statins, ezetimibe and PCSK inhibitors, alone or in combination are the front and center of the therapeutic approaches for reducing LDL-C and its CV consequences, in recent years nutraceuticals and functional foods have increasingly been considered as a valid support in the reduction of LDL-C, especially in patients with mild/moderate hyperlipidemia - therefore not requiring pharmacological treatment - or in patients intolerant to statins or other drugs. An approach also shared by the European Atherosclerosis Society (EAS). Of the various active ingredients with hypolipidemic properties, we include the artichoke (Cynara cardunculus, Cynara scolymus) and the bergamot (Citrus bergamia) which, thanks essentially to the significant presence of polyphenols in their extracts, can exert this action associated with a number of other complementary inflammation and oxidation benefits. In light of these evidence, this review aimed to describe the effects of artichoke and bergamot in modifying the lipid and inflammatory parameters described in in vitro, in vivo and clinical studies. The available data support the use of standardized compositions of artichoke and bergamot extracts, alone or in combination, in the treatment of mild to moderate dyslipidemia, in patients suffering from metabolic syndrome, hepatic steatosis, or intolerant to common hypolipidemic treatments.

Purification and In Vitro Evaluation of an Anti-HER2 Affibody-Monomethyl Auristatin E Conjugate in HER2-Positive Cancer Cells

Simple Summary

Antibody-drug conjugates (ADCs) represent an innovative class of anticancer agents specifically aimed at targeting cancer cells, reducing damage to healthy tissues but showing some weaknesses. A promising approach for the development of high-affinity tumor targeting ADCs is the use of engineered protein drugs, such as affibody molecules. Our aim was to develop a more efficient purification method for the cytotoxic conjugate Z_HER2:2891DCS-MMAE that targets human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells. The conjugate is based on Z_HER2:2891 affibody and a drug conjugation sequence (DCS), which allowed for site-specific conjugation of the cytotoxic auristatin E molecule (MMAE) to the affibody. We tested the in vitro efficacy of Z_HER2:2891DCS-MMAE on several parameters, such as cell viability, proliferation, migration, and apoptosis. Our results confirmed that the cytotoxic conjugate efficiently interacts with high affinity with HER2 positive cancer cells, allowing the selective and specific delivery of the cytotoxic payload.

Abstract

A promising approach for the development of high-affinity tumor targeting ADCs is the use of engineered protein drugs, such as affibody molecules, which represent a valuable alternative to monoclonal antibodies (mAbs) in cancer-targeted therapy. We developed a method for a more efficient purification of the Z_HER2:2891DCS affibody conjugated with the cytotoxic antimitotic agent auristatin E (MMAE), and its efficacy was tested in vitro on cell viability, proliferation, migration, and apoptosis. The effects of Z_HER2:2891DCS-MMAE were compared with the clinically approved monoclonal antibody trastuzumab (Herceptin^®). To demonstrate that Z_HER2:2891DCS-MMAE can selectively target HER2 overexpressing tumor cells, we used three different cell lines: the human adenocarcinoma cell lines SK-BR-3 and ZR-75-1, both overexpressing HER2, and the triple-negative breast cancer cell line MDA-MB-231. MTT assay showed that Z_HER2:2891DCS-MMAE induces a significant time-dependent toxic effect in SK-BR-3 cells. A 30% reduction of cell viability was already found after 10 min exposure at a concentration of 7 nM (IC₅₀ of 80.2 nM). On the contrary, MDA-MB-231 cells, which express basal levels of HER2, were not affected by the conjugate. The cytotoxic effect of the Z_HER2:2891DCS-MMAE was confirmed by measuring apoptosis by flow cytometry. In SK-BR-3 cells, increasing concentrations of conjugated affibody induced cell death starting from 10 min of treatment, with the strongest effect observed after 48 h. Overall, these results demonstrate that the ADC, formed by the anti-HER2 affibody conjugated to monomethyl auristatin E, efficiently interacts with high affinity with HER2 positive cancer cells in vitro, allowing the selective and specific delivery of the cytotoxic payload.

Aortic Gene Expression Profiles Show How ApoA-I Levels Modulate Inflammation, Lysosomal Activity, and Sphingolipid Metabolism in Murine Atherosclerosis

OBJECTIVE

HDL (high-density lipoprotein) particles are known to possess several antiatherogenic properties that include the removal of excess cholesterol from peripheral tissues, the maintenance of endothelial integrity, antioxidant, and anti-inflammatory activities. ApoA-I overexpression in apoE-deficient (EKO) mice has been shown to increase HDL levels and to strongly reduce atherosclerosis development. The aim of the study was to investigate gene expression patterns associated with atherosclerosis development in the aorta of EKO mice and how HDL plasma levels relate to gene expression patterns at different stages of atherosclerosis development and with different dietary treatments. Approach and Results: Eight-week-old EKO mice, EKO mice overexpressing human apoA-I, and wild-type mice as controls were fed either normal laboratory or Western diet for 6 or 22 weeks. Cholesterol distribution among lipoproteins was evaluated, and atherosclerosis of the aorta was quantified. High-throughput sequencing technologies were used to analyze the transcriptome of the aorta of the 3 genotypes in each experimental condition. In addition to the well-known activation of inflammation and immune response, the impairment of sphingolipid metabolism, phagosome-lysosome system, and osteoclast differentiation emerged as relevant players in atherosclerosis development. The reduced atherosclerotic burden in the aorta of EKO mice expressing high levels of apoA-I was accompanied by a reduced activation of immune system markers, as well as reduced perturbation of lysosomal activity and a better regulation of the sphingolipid synthesis pathway.

CONCLUSIONS

ApoA-I modulates atherosclerosis development in the aorta of EKO mice affecting the expression of pathways additional to those associated with inflammation and immune response.

Small molecule 3PO inhibits glycolysis but does not bind to 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3)

6-Phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoform 3 (PFKFB3) is a key enzyme of the glycolytic pathway, and it plays an essential role in angiogenesis. 3-(3-Pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) is frequently used as a glycolysis inhibitor and is thought to inhibit PFKFB3. However, this latter effect of 3PO has never been investigated in detail and was the aim of the present study. To demonstrate binding of 3PO to PFKFB3, we used isothermal titration calorimetry. However, 3PO did not bind to PFKFB3, even up to 750 µm, in contrast to 3 µm of AZ67, which is a potent and specific PFKFB3 inhibitor. Instead, 3PO accumulated lactic acid inside the cells, leading to a decrease in the intracellular pH and an inhibition of enzymatic reactions of the glycolytic pathway.

Pharmacokinetic drug interactions of the non-vitamin K antagonist oral anticoagulants (NOACs)

The use of warfarin, the most commonly prescribed oral anticoagulant, is being questioned by clinicians worldwide due to warfarin several limitations (a limited therapeutic window and significant variability in dose-response among individuals, in addition to a potential for drug-drug interactions). Therefore, the need for non-vitamin K antagonist oral anticoagulants (NOACs) with a rapid onset of antithrombotic effects and a predictable pharmacokinetic (PK) and pharmacodynamic (PD) profile led to the approval of five new drugs: the direct factor Xa (F-Xa) inhibitors rivaroxaban, apixaban, edoxaban and betrixaban (newly approved by FDA) and the direct thrombin (factor-IIa) inhibitor dabigatran etexilate. The advantages of NOACs over warfarin are a fixed-dosage, the absence of the need for drug monitoring for changes in anti-coagulation and fewer clinically significant PK and PD drug-drug interactions. NOACs exposure will likely be increased by the administration of strong P-glycoprotein (P-gp) and cytochrome P450 (CYP) 3A4-inhibitors and may increase the risk of bleeds. On the contrary, P-gp inducers could significantly decrease the NOACs plasma concentration with an associated reduction in their anticoagulant effects. This manuscript gives an overview of NOACs PK profiles and their drug-drug interactions potential. This is meant to be of help to physicians in choosing the best therapeutic approach for their patients.

Abstract 435: Inhibition of the Key Glycolytic Enzyme PFKFB3 with Novel Compounds Suppresses Angiogenesis

Aim: Intraplaque angiogenesis is an important contributor to atherosclerotic plaque growth and instability. Angiogenic signals induce endothelial cells (ECs) to switch their metabolism to being highly glycolytic, enabling their growth and division. Glycolytic modulation by inhibition of the glycolytic activator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3) has been shown to reduce angiogenesis. The objective of this study was to identify novel anti-angiogenic compounds with a potential to efficiently modulate (inhibit) angiogenesis.

Methods: Using the human EC line EA.hy926, we studied the effects of PFKFB3 inhibition with 3PO, a weak competitive inhibitor of PFKFB3, and of two potent self-synthesized phenoxindazole analogues (PA-1 and PA-2) on glycolysis, proliferation, migration, matrix metalloproteinase (MMP) activity, and capillary tube formation. Moreover, gene expression of important markers related to angiogenesis were measured at mRNA level by real-time PCR.

Results: PFKFB3 inhibition with all three tested compounds significantly reduced glycolytic activity. While PA-1 and PA-2 suppressed capillary tube formation, 3PO did not have any effect. Accordingly, PA-1 and PA-2 markedly inhibited EC migration, proliferation and wound closing capacity which are essential for neovessel formation. Moreover, these inhibitors downregulated gelatinase gene expression up to 6-fold, as well reduced the activity of proMMP-9 and MMP-2 up to 50% and 30% compared to control, respectively. Gene expression analysis revealed that the PA compounds downregulated PFKFB3 expression whilst 3PO did not. Similarly, markers of migration and angiogenesis, such as CCL5, VCAM-1, VEGFA and VEGFR2, were also markedly reduced (up to 10-fold) by the PA compounds.

Conclusions: These findings suggest that PFKFB3 inhibition with PA compounds may interfere with key pro-angiogenic functions, such as endothelial migration, proliferation and capillary-like structure formation and this exerts a multitarget anti-angiogenic activity. Hence, PFKFB3 inhibition with PA compounds is a promising therapeutic approach to promote plaque stability.

Abstract 605: Inhibition of the Key Glycolytic Enzyme PFKFB3 with Novel Compounds Suppresses Angiogenesis

Aim: Intraplaque angiogenesis is an important contributor to atherosclerotic plaque growth and instability. Angiogenic signals induce endothelial cells (ECs) to switch their metabolism to being highly glycolytic, enabling their growth and division. Glycolytic modulation by inhibition of theglycolytic activator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3) has been shown to reduce angiogenesis. The objective of this study was to identify novel anti-angiogenic compoundswith a potential to efficiently modulate (inhibit) angiogenesis.

Methods: Using the human EC line EA.hy926, we studied the effects of PFKFB3 inhibition with 3PO, a weak competitive inhibitor of PFKFB3, and of two potent self-synthesized phenoxindazole analogues (PA-1 and PA-2) on glycolysis, proliferation, migration, matrix metalloproteinase (MMP) activity, and capillary tube formation. Moreover, gene expression of important markers related to angiogenesis were measured at mRNA levelby real-time PCR.

Results: PFKFB3 inhibition with all three tested compounds significantly reduced glycolytic activity. While PA-1 and PA-2suppressedcapillary tube formation, 3PO did not have any effect. Accordingly, PA-1 and PA-2 markedly inhibited EC migration, proliferation and wound closing capacity which are essential for neovessel formation. Moreover, these inhibitors downregulated gelatinase gene expression up to 6-fold, as well reduced the activity of proMMP-9 and MMP-2 up to 50% and 30% compared to control, respectively. Gene expression analysis revealed that the PA compounds downregulated PFKFB3 expression whilst 3PO did not. Similarly, markers of migration and angiogenesis, such as CCL5, VCAM-1, VEGFA and VEGFR2, were also markedly reduced (up to 10-fold) by the PA compounds.

Conclusions: These findings suggest that PFKFB3 inhibition with PA compounds may interfere with key pro-angiogenic functions, such as endothelial migration, proliferation and capillary-like structure formation and this exerts a multitarget anti-angiogenic activity. Hence, PFKFB3 inhibition with PA compounds is a promising therapeuticapproach to promote plaque stability.

Proprotein Convertase Subtilisin-Kexin type-9 (PCSK9) and triglyceride-rich lipoprotein metabolism: Facts and gaps

After more than a decade of intense investigation, Pro-protein Convertase Subtilisin-Kexin type 9 (PCSK9) remains a hot topic of research both at experimental and clinical level. Interestingly PCSK9 is expressed in different tissues suggesting the existence of additional function(s) beyond the modulation of the Low-Density Lipoprotein (LDL) receptor in the liver. Emerging data suggest that PCSK9 might play a role in the modulation of triglyceride-rich lipoprotein (TGRL) metabolism, mainly Very Low-Density Lipoproteins (VLDL) and their remnants. In vitro, PCSK9 affects TGRLs production by intestinal cells as well as the catabolism of LDL receptor homologous and non-homologous targets such as VLDL receptor, CD36 and ApoE2R. However, the in vivo relevance of these findings is still debated. This review aims at critically discussing the role of PCSK9 on TGRLs metabolism with a major focus on the impact of its genetic and pharmacological modulation on circulating lipids and lipoproteins beyond LDL.

Dietary polyphenols and regulation of gelatinase expression and activity

The interaction of cells with the extracellular matrix (ECM) is critical for the normal development and function of organisms. The matrix metalloproteinases (MMPs) are a family of Zn++ and Ca++ dependent endopeptidases, which are key mediators of ECM remodelling. The turnover and remodelling of ECM must be tightly regulated, since uncontrolled proteolysis would contribute to abnormal development and to the generation of many pathological conditions characterized by either excessive degradation, or lack of degradation of ECM components. In particular, the gelatinases (MMP-2 and –9) are abundantly expressed in various malignant tumors, play an active role in angiogenesis, and may also influence the process of atherosclerotic lesion formation. In recent years, much consideration has been given to the role of diet in preventing degenerative diseases, such as cancer and cardiovascular diseases. Polyphenols are abundant components/micronutrients of the human diet that have been shown in vitro to profoundly affect ECM turnover by regulating gelatinases expression and activity, acting at both the pre- and post-transcriptional level. Therefore, they could have a beneficial effect in many pathological conditions implicated in connective tissue destruction and remodelling associated with degenerative diseases.

The dataset describes: Phenotypic changes induced by cholesterol loading in smooth muscle cells isolated from the aortae of C57BL/6 mice

The data presented in this article is related to the research article entitled "ABCA1 and HDL₃ are Required to Modulate Smooth Muscle Cells Phenotypic Switch after Cholesterol Loading" (Castiglioni et al., 2017) [1]. This data describes the characterization of the phenotypic changes induced by cholesterol loading in smooth muscle cells (SMCs) isolated from the aortae of C57BL/6 mice. Upon cholesterol loading, there is a significant and concentration-dependent decrease in the expression of Acta2 and a parallel increase in Mac-2, and ATP binding cassette (ABC) transporters Abca1 and Abcg1. Cholesterol incubation causes the transformation of SMCs into foam cells with a 3-fold increase in cellular total cholesterol content and a 2.5-fold stimulation of the activity of the esterifying enzyme Acyl-CoA:cholesterol acyltransferase (ACAT). The addition of the same amount of cholesterol, either dissolved in ethanol or as lipoprotein cholesterol (AcLDL or native LDL) only slightly induces the activity of the enzyme ACAT, and does not cause the accumulation of lipid droplets into SMCs. We describe also the knock down of ABCA1 expression by siRNA treatment in mouse smooth muscle cells.

ABCA1 and HDL3 are required to modulate smooth muscle cells phenotypic switch after cholesterol loading

BACKGROUND AND AIMS

Cholesterol-loaded smooth muscle cells (SMCs) modify their phenotypic behavior becoming foam cells. To characterize the role of ABCA1 and HDL3 in this process, we evaluated HDL3 effects on cholesterol-induced phenotypic changes in SMCs expressing or not ABCA1.

METHODS

SMCs, isolated from the aortae of wild-type (WT) and Abca1 knock-out (KO) mice, were cholesterol-loaded using a "water-soluble cholesterol''.

RESULTS

Cholesterol loading downregulates the expression of Acta2 and calponin (SMC markers), and increases the expression of Mac-2, CD11b and MHCII (inflammation-related genes and surface antigens) and Abca1, Abcg1. HDL3 normalizes SMC marker expression and reduces the expression of inflammation-related genes/proteins in WT cells, an effect not observed with free apoA-I. The effect of HDL3 is almost lost in Abca1 KO cells, as well as when Abca1 is silenced in WT SMC. HDL3 does not differently affect cholesterol downloading in WT or KO cells and stimulates phospholipids removal in WT cells. Similarly, the expression of myocardin and its modulators, such as miR-143/145, is reduced by cholesterol loading in WT and Abca1 KO SMCs; HDL3 normalizes their levels in WT cells but not in KO cells. On the contrary, cholesterol loading induces Klf4 expression while HDL3 restores Klf4 to basal levels in WT cells, but again this effect is not observed in KO cells.

CONCLUSIONS

Our results indicate that HDL3, by interacting with ABCA1, modulates the miR143/145-myocardin axis and prevents the cholesterol-induced gene expression modification in SMCs regardless of its cholesterol unloading capacity.

Statin drug interactions and related adverse reactions: an update

INTRODUCTION

Statins reduce the risk of cardiovascular morbidity and mortality in patients with or at risk for cardiovascular disease and their use is expanding, especially in elderly. Statins are prescribed on a long-term basis and may undergo drug-drug interactions (DDIs) with other drugs. Statins have different safety and tolerability, and this might affect the possibility of DDIs with other cardiovascular drugs, increasing the risk of statin-associated myopathy and hepatotoxicity. Polypharmacy and pharmacogenetic variability are potential causes of statin DDIs. Thus, the safety and adverse effects of statins, particularly in patients receiving multiple medications at risk of DDIs, are a matter of special concern.

AREAS COVERED

The purpose of this manuscript is to give an update on the potential statin DDIs and related adverse drug reactions (myopathy and hepatotoxicity), with special considerations on polypharmacy in elderly population, HIV patients, cardiovascular drugs and liver toxicities. The potential DDIs among statins and monoclonal antibodies including the recently approved PCSK9 inhibitors are also extensively discussed in the present review.

EXPERT OPINION

A better understanding of the incidence and clinical significance of statin DDIs will help physicians in fine-tuning the lipid-lowering therapeutic interventions thus providing their patients with an evidence-based, safe and cost-effective clinical support.

Abstract 238: ABCA1 and HDL3 are Required to Modulate Smooth Muscle Cells Trandifferentiation in a Myocardin-miR143/145-dependent Process

Cells of the artery wall may accumulate free cholesterol and cholesteryl esters becoming foam cells. Up to 50% of foam cells in human lesions originates from smooth muscle cells (SMCs). Arterial SMCs express the ATP binding cassette (ABC) transporter ABCA1 and, upon cholesterol loading, express macrophage markers and a phagocytic activity. To characterize the role of ABCA1 and HDL3 in this transdifferentiation process, we evaluated the phenotypic changes in SMCs isolated from wild type (WT) and ABCA1 knock out (KO) mice and how HDL3 affects these changes. Cholesterol loading causes the downregulation of the expression of SMC markers including ACTA2, alpha-tropomyosin and myosin heavy chain and increases the expression of macrophage-related genes such as CD68, Mac-2, SRB1, MMPs, ABCG1 and ABCA1. HDL3 treatment in WT cells is able to normalize the expression of ACTA2, while the expression of macrophage-related genes is reduced. On the contrary, the preventive effect of HDL3 is completely lost in ABCA1 KO cells. Interestingly, the presence of HDL3 does not differently affect neutral lipid accumulation in WT or ABCA1 KO cells but stimulates phospholipids removal only in WT cells. ApoAI addition does not reverse the phenotypic changes induced by cholesterol not only in KO but also in WT cells. Moreover, cholesterol loading reduces the expression of myocardin, the master SMC specific-transcriptional coactivator involved in SMC differentiation, by up to 55% (p<0.01 vs respective control) in both cell types. HDL3 normalizes myocardin levels in WT cells while it does not have any effect in ABCA1 KO cells. Similar results are obtained evaluating the levels of miR-143/145, which positively regulate myocardin. The basal expression level of KLF4, a myocardin repressor, is almost double in ABCA1 KO cells compared to WT. After cholesterol loading, KLF4 is slightly reduced in WT cells, while its expression is halved in ABCA1 KO cells. HDL3 restores KLF4 to basal levels in KO cells, but it further reduces them in WT cells. These results indicate that HDL3, modulating the miR143/145-myocardin axis in SMC, prevents the cholesterol-induced gene expression modification regardless of its cholesterol unloading capacity and the presence of ABCA1 is required.

Abstract 138: Cigarette Smoke and Monocytes Induce Endothelial Dysfunction

Cigarette smoke induces endothelial cell (EC) dysfunction. Circulating monocytes (HM) adhere to a damaged endothelium and migrate into the intima, differentiate to macrophages and contribute to atherosclerotic plaque growth. We demonstrated that HM exposed to cigarette smoke condensate (CSC) increase the transmigration of HM through EC. Thus, we hypothesized that CSC may affect HM/EC interaction. We analyzed the effects on EC of CSC (30 μg/ml) alone and/or of medium conditioned by HM incubated without (CM) or with CSC (CM/CSC). CSC, CM or CM/CSC did not affect EC vitality (MTT assay). CM and CM/CSC increased the expression (measured by RT-PCR) of adhesion molecule ICAM1 (36-fold and 90-fold, p<0.01 vs control or CM, respectively). The effect on VCAM1 was even more dramatic (63-fold vs control for CM, p<0.01 and 725-fold vs control, p<0.01 with CM/CSC). In addition, CM and CM/CSC enhanced the expression of matrix metalloproteinase (MMP)-3 (+60% vs control, p<0.01; +200% vs control, p<0.01, respectively) and MMP-9 (+70% vs control, p<0.01; +140% vs control, p<0.01, respectively). MMP-1 and MMP-2 were not affected. Then, we used the iCELLigence System to analyze EC biological status (cell number, adhesion, viability, and morphology). Only the addition of CM/CSC to confluent EC monolayer dramatically modified the pattern of the electric flow, indicative of modifications in EC morphology. Indeed, we observed an altered actin cytoskeleton organization by immunofluorescence studies performed with FITC-phalloidin. In particular, CM/CSC caused the shrinking of the EC cytoplasm by about 50% (p<0.01 vs control or CM). Moreover, CM/CSC altered sub-cellular localization of beta-catenin promoting its trafficking from membrane into the cytosol and the nucleus. In contrast, EC morphology was not affected by exposure to CSC or CM. Finally, CM and CM/CSC reduced (by 40% and 60%, p<0.05, respectively) the expression of the small signaling G protein Rac 1 GTPase involved in cytoskeletal remodeling. In conclusion, these results indicate that monocytes, in the presence of cigarette smoke, secrete some soluble factors that affect endothelium morphology, thus increasing its permeability and facilitating monocytes transmigration through the endothelial monolayer.

Cigarette smoke condensate affects monocyte interaction with endothelium

OBJECTIVE

Circulating monocytes adhere to the endothelium and migrate into the intima contributing to atherosclerotic plaque growth. Cigarette smoke is a risk factor for atherosclerosis, but it is not completely known how it affects monocyte behavior in atherogenesis.

METHODS

We studied the effects of cigarette smoke condensate (CSC) on human monocytes (HM) chemotaxis and transmigration through an endothelial cell (EC) monolayer.

RESULTS

Pre-treatment with CSC caused a decrease in HM chemotaxis and transmigration (-55% and -18% vs control, p < 0.05, respectively), paralleled by a reduced expression of Rac 1 GTPase. On the contrary, direct exposure of both HM and EC to CSC increased (+23% vs control, p < 0.05) HM transmigration, paralleled by a strong stimulation of VCAM1 and ICAM1 expression by ECs, and by a slight increase in monocyte integrin expression. An enhancement of monocyte transmigration was obtained after the exposure of both HM and EC to medium conditioned by HM previously incubated with CSC (+265% vs control, p < 0.001). CSC showed a stimulatory effect on the expression by HM of TLR4, MCP1, IL8, IL1beta, and TNFalfa, which was ablated by pre treatment with PDTC. Incubation with neutralizing antibodies against both MCP1 or IL8 completely abolished the CSC-conditioned medium induced HM transmigration.

CONCLUSIONS

CSC induces HM to release chemotactic factor(s), which amplify the recruitment and transmigration of inflammatory cells through EC, but CSC may also reduce HM migratory capacity. Therefore, exposure to CSC affects monocyte behavior and interaction with the endothelium, thus potentially facilitating and/or further aggravating the atherogenic process.

Statin drug interactions and related adverse reactions

INTRODUCTION

Statin monotherapy is generally well tolerated, with a low frequency of adverse events. The most important adverse effects associated with statins are myopathy and an asymptomatic increase in hepatic transaminases, both of which occur infrequently. Because statins are prescribed on a long-term basis, their possible interactions with other drugs deserve particular attention, as many patients will typically receive pharmacological therapy for concomitant conditions during the course of statin treatment.

AREAS COVERED

This review summarizes the pharmacokinetic properties of statins and emphasizes their clinically relevant drug interactions and related adverse reactions.

EXPERT OPINION

Avoiding drug-drug interactions and consequent adverse drug reactions is essential in order to optimize compliance, and thus improve the treatment of patients at high cardiovascular risk. The different pharmacokinetic profiles among statins should be carefully considered, in order to understand the possible spectrum of drug interactions. The growing trend toward earlier statin treatment for the prevention of cardiovascular disease means that physicians must anticipate future polypharmacy when their patients require additional medications for comorbid conditions.

Olive oil phenols modulate the expression of metalloproteinase 9 in THP-1 cells by acting on nuclear factor-kappaB signaling

In vivo studies suggest that the phenolic component contributes to the anti-inflammatory and antiatherosclerotic actions of olive oil; however, the effects in circulating cells are not fully characterized. Monocytes play a key role in inflammation-based diseases by expressing several molecules, including metalloproteinases (MMPs). In the present study, we investigated the effects of olive oil phenolic extract and individual compounds on MMP-9 in THP-1 cells, a human monocyte-like cell line. Olive oil extract prevented the stimulation of MMP-9 expression and secretion in tumor necrosis factor alpha-treated THP-1 cells. Oleuropein aglycone, a typical olive oil phenol, was active at concentrations found in the extract, although other compounds probably contribute to the biological activity. We also found that the effect of the extract and individual compounds on MMP-9 is due to impaired nuclear factor-kappaB signaling. Our findings provide further evidence on the mechanisms by which olive oil reduces the inflammatory burden associated with disorders, such as atherosclerosis.

Thiol supplementation inhibits metalloproteinase activity independent of glutathione status

Matrix metalloproteinases (MMPs) are proteolytic enzymes that regulate both integrity and composition of the extracellular matrix (ECM). Excessive ECM breakdown by MMPs is implicated in many physiological and pathological conditions, such as atherosclerosis. Activated macrophages, especially in the atherosclerotic lesion, are a major source of reactive oxygen species (ROS). Antioxidants protect against ROS-induced MMPs activation and inhibit gelatinolytic activity. We sought to determine whether the antioxidants glutathione (GSH), N-acetylcysteine (NAC), or lipoic acid (LA) affect gelatinase production and secretion. The results show that thiol compounds affect MMPs expression and activity in different ways. MMP-2 activity is directly inhibited by NAC and GSH, while LA is ineffective. On the contrary, MMP-9 expression is inhibited by LA at a pretrascriptional level, and MMP-9 activity is stimulated by GSH through a direct interaction with the gelatinase itself. Although all thiols, these compounds have different properties and different cellular uptakes and metabolic characteristics, and this could explain, at least in part, their differential effects on MMPs.

Raloxifene inhibits matrix metalloproteinases expression and activity in macrophages and smooth muscle cells

Secretion of matrix metalloproteinases (MMPs) by macrophages and smooth muscle cells (SMC) may impair atherosclerotic cap integrity leading to atherosclerosis complications. Selective estrogen receptor modulators (SERMs) have favourable impact on plasma lipid levels, but their role in the prevention of atherosclerosis still remains unclear. We investigated the effects of raloxifene, a second generation SERM, on MMP expression and activity in cultured macrophages and SMC, and in rabbit carotid lesions. Human monocyte-derived macrophages were isolated from blood of healthy donors. SMC were isolated from the intima-media layers of collared rabbit carotid arteries. Cells were incubated for 24h with increasing concentrations of raloxifene. Ovariectomized rabbits fed a 1% cholesterol-rich diet were subjected to pericarotid collar placement and treated with or without 10mgkg(-1)d(-1) raloxifene for 2 weeks. In macrophages, raloxifene treatment (0.1-10microM) significantly reduced MMP-9 gelatinolytic potential in a concentration-dependent manner, without affecting MMP-9 activation. This effect was estrogen receptor (ER)-dependent and due to the inhibition of MMP-9 promoter-driven transcription following an interaction with NF-kB pathway. Similarly, in cultured SMC, raloxifene inhibited up to 40% MMP-2 gelatinolytic activity. In vivo, raloxifene decreased the expression of MMP-2, MMP-3, and MMP-9 by intimal cells and the total gelatinolytic activity of collared carotids. These effects were accompanied by reduction of lesion size and inhibition of macrophage accumulation. Overall, results indicate that raloxifene may reduce MMPs expression and activity in macrophages and smooth muscle cells and favourably affect lesion formation.

Perivascular carotid collar placement induces neointima formation and outward arterial remodeling in mice independent of apolipoprotein E deficiency or Western-type diet feeding

We investigated the influence of apolipoprotein E deficiency and Western-type diet feeding on the development and composition of neointimal lesions induced by periadventitial carotid placement of a non-occlusive collar in mice. ApoE-/- and wild-type mice were fed a Western-type diet or chow diet for 4 weeks before collar surgery. Diets were continued after collar placement for 6 or 12 weeks. Compared to sham-operated arteries, collared carotids showed significant neointima formation, lumen loss, and outward remodeling in both apoE-/- and wild-type mice. These changes were not affected by either the genotype or the diet. Conversely, significant differences in neointima composition were detected between the two genotypes, with apoE-/- mice showing greater lipid deposition and lower SMC accumulation compared to wild-type mice, independent of the dietetic regimen. Altogether, the results of the present study indicate that although lesion composition may be influenced by genotype, neointima formation and arterial remodeling in the murine perivascular carotid collar model occur independent of the exposure to atherogenic diet or the presence of a sensitized genotype such as apoE-/-. The murine perivascular carotid collar model would thus be suitable for investigating neointima formation, arterial remodeling, and their potential pharmacological modulation in the setting of different genetic and dietary conditions.

Rosuvastatin treatment prevents progressive kidney inflammation and fibrosis in stroke-prone rats

Salt-loaded, spontaneously hypertensive stroke-prone rats show progressive increases in blood pressure and proteinuria and accumulate acute-phase proteins in body fluids, modeling events during renal damage. The aim of this study was to assess the pathological events occurring in the kidney of spontaneously hypertensive stroke-prone rats over time and evaluate the effects of statin treatment, which is known to improve renal and cardiovascular outcomes. Kidneys of male spontaneously hypertensive stroke-prone rats euthanized at different stages of proteinuria showed progressive inflammatory cell infiltration, the accumulation of alpha-smooth muscle actin-positive cells, degenerative changes in podocytes, and severe fibrosis. These were accompanied by an imbalance in the plasminogen/plasmin and metalloprotease systems characterized by the increased renal expression of plasminogen activator inhibitor-1, tissue plasminogen activator, and urokinase plasminogen activator; the net result was an increase in plasmin and matrix metalloproteinase (MMP)-2 and a reduction in MMP-9 activity. Chronic treatment with the hydrophilic rosuvastatin had renoprotective effects in terms of morphology and inflammation and prevented the changes in plasmin, MMP-2, and MMP-9 activity. These effects were independent of the changes in blood pressure and plasma lipid levels. Treatment with the lipophilic simvastatin was not renoprotective. These data suggest that rosuvastatin may have potential utility as a therapeutic option in renal diseases that are characterized by inflammation and fibrosis.

Rosuvastatin displays anti-atherothrombotic and anti-inflammatory properties in apoE-deficient mice

Inflammation contributes importantly to all stages of atherosclerosis, including the onset of acute thrombotic complications. In clinical trials, statins are beneficial in the primary and secondary prevention of coronary heart disease. Moreover, statins have been shown to possess several pleiotropic properties independent of cholesterol lowering in experimental settings. Based on these premises, we investigated the anti-inflammatory and anti-atherothrombotic properties of rosuvastatin in vivo, testing its effect on cholesterol and monocyte accumulation, and on adhesion molecules and tissue factor (TF) expression. ApoE-deficient female mice were fed a cholesterol-rich diet containing rosuvastatin (0, 1, 2 or 10 mg kg(-1)d(-1)) for 12 weeks. Treatment with rosuvastatin did not significantly affect either body weight gain or plasma total cholesterol (C) and triglyceride levels. However, rosuvastatin treatment dose-dependently reduced ICAM-1 expression in the aortic valves (V) (up to 40% inhibition, p<0.05) and in the proximal segment of the ascending aorta (AA) (-50%, p<0.001). Similarly, rosuvastatin inhibited VCAM-1 expression in the V (-40%) and in the AA (-35%, p<0.05). Moreover, there was a reduced accumulation of macrophages in the V in a dose-dependent and statistically significant manner (-45%, p<0.01). These anti-inflammatory effects were reflected in a reduction of cholesterol deposition in the entire aorta, both in the free and in the esterified form. Finally, the expression of tissue factor, the most potent pro-thrombogenic agent, was consistently reduced in AA by rosuvastatin treatment (-71%, p<0.001). Altogether, these data demonstrate that rosuvastatin has anti-inflammatory and anti-atherothrombotic activities in apoE-deficient mice that could translate in a beneficial effect on atherogenesis.

Inhibition of MMP-2 activation and release as a novel mechanism for HDL-induced cardioprotection

High density lipoproteins (HDL) protect the heart against ischemia/reperfusion (I/R) injury, and matrix metalloproteinase-2 (MMP-2) directly contributes to cardiac contractile dysfunction after I/R. To investigate the possible involvement of MMP-2 inhibition in HDL-mediated cardioprotection, isolated rat hearts underwent 20 min of low-flow ischemia and 30 min of reperfusion. Plasma-derived and synthetic HDL attenuated the I/R-induced cardiac MMP-2 activation and release in a dose-dependent way. The attenuation of I/R-induced MMP-2 activation by HDL correlated with the reduction of post-ischemic contractile dysfunction and cardiomyocyte necrosis. These results indicate prevention of MMP-2 activation as a novel mechanism for HDL-mediated cardioprotection.

Hypolipidemic therapy for the metabolic syndrome

The metabolic syndrome appears to affect a significant proportion of the population and is associated with increased risk for development of cardiovascular disease as well as of type-2 diabetes. No single treatment for the metabolic syndrome as a whole yet exists. While the primary management of patients with the metabolic syndrome involves healthy lifestyle promotion, the atherogenic dyslipidemia is a primary target for cardiovascular disease risk reduction in these patients. Statin therapy provides effective reduction of LDL-cholesterol, which represents the primary therapeutic goal of lipid-lowering therapy in patients at risk for cardiovascular disease. Fibrates in turn are effective in normalizing lipid levels (mainly triglycerides and HDL-cholesterol) in patients with the metabolic syndrome and may improve insulin resistance. Whereas statins remain the drug of choice for patients who need to achieve the LDL-cholesterol goal, fibrate therapy may represent an alternative for those with low HDL-cholesterol and high triglyceride levels. The simultaneous use of fibrates could be indicated in patients whose LDL-cholesterol is controlled by statin therapy but whose HDL-cholesterol and/or triglycerides are still inappropriate. Such a combination, however, needs careful monitoring due to the potential hazard of adverse drug interactions. Nicotinic acid and ezetimibe may be useful agents for therapy, particularly when combined with statins. A number of emerging therapies offer potential as future options for the pharmacological treatment of metabolic syndrome.