PCSK9 Expression in Epicardial Adipose Tissue: Molecular Association with Local Tissue Inflammation

Dozio, Elena; Ruscica, Massimiliano; Vianello, Elena; Macchi, Chiara; Sitzia, Clementina; Schmitz, Gerd; Tacchini, Lorenza; Corsi Romanelli, Massimiliano M.

doi:https://doi.org/10.1155/2020/1348913

Mediators of Inflammation

On this page

Abstract Introduction Materials and Methods Results Discussion Data Availability Conflicts of Interest Authors’ Contributions Acknowledgments Supplementary Materials References Copyright Related Articles

Research Article | Open Access

Volume 2020 | Article ID 1348913 | https://doi.org/10.1155/2020/1348913

PCSK9 Expression in Epicardial Adipose Tissue: Molecular Association with Local Tissue Inflammation

Elena Dozio,¹Massimiliano Ruscica,²Elena Vianello,¹Chiara Macchi,²Clementina Sitzia,¹Gerd Schmitz,³Lorenza Tacchini,¹and Massimiliano M. Corsi Romanelli^1,4

Academic Editor: Alex Kleinjan

Received23 Mar 2020

Accepted21 May 2020

Published04 Jun 2020

Abstract

Epicardial adipose tissue (EAT) has the unique property to release mediators that nourish the heart in healthy conditions, an effect that becomes detrimental when volume expands and proinflammatory cytokines start to be produced. Proprotein convertase subtilisin/kexin type 9 (PCSK9), a proinflammatory mediator involved in atherosclerosis, is also produced by visceral fat. Due to the correlation of inflammation with PCSK9 and EAT enlargement, we evaluated whether PCSK9 was expressed in EAT and associated with EAT inflammation and volume. EAT samples were isolated during surgery. EAT thickness was measured by echocardiography. A microarray was used to explore EAT transcriptoma. The PCSK9 protein levels were measured by Western Blot in EAT and ELISA in plasma. PCSK9 was expressed at both the gene and protein levels in EAT. We found a positive association with EAT thickness and local proinflammatory mediators, in particular, chemokines for monocytes and lymphocytes. No association was found with the circulating PCSK9 level. The expression of PCSK9 in EAT argues that PCSK9 is part of the EAT secretome and EAT inflammation is associated with local PCSK9 expression, regardless of circulating PCSK9 levels. Whether reducing EAT inflammation or PCSK9 local levels may have beneficial effects on EAT metabolism and cardiovascular risk needs further investigations.

1. Introduction

Proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key regulators of the LDL receptor (LDLR), is a soluble member of the mammalian proprotein convertase family of secretory serine endoproteases [1]. While the liver is the main contributor to circulating PCSK9, other tissues produce PCSK9 pointing out its possible role beyond LDLR expression [2, 3]. PCSK9 seems to play a role in atherosclerotic plaque development, i.e., it is expressed in endothelial cells, regulates the migration ability of smooth muscle cells [4], and is raised by shear stress [5]. Circulating platelets have also been added to the list of PCSK9 targets [6], together with the description of a proinflammatory effect on macrophages [7].

It is well-established that body fat accumulation leads to metabolic diseases and increases cardiovascular (CV) risk [8]. Among different fat depots, the visceral epicardial adipose tissue (EAT) is an important risk factor for CV diseases (CVD), from atherosclerosis to cardiac remodeling, heart failure, valve calcification, and stenosis [9–16]. Although in physiological conditions, EAT nourishes the heart and plays protective functions, e.g., mechanical protection of coronaries, local energy store, and cryoprotection of the heart [17], when EAT volume expands, it becomes detrimental. These effects are mainly due to the release of bioactive molecules that affect the electrophysiological and contractile properties of cardiomyocytes and that promote cardiac remodeling, fibrosis, and coronary atherosclerosis progression [18]. Indeed, EAT lies in continuity to the myocardium and shares the same microcirculation. Vasocrine and paracrine interactions of bioactive molecules with coronary vessels and the myocardium exist. EAT hypertrophy promotes adipocyte degeneration and drives local inflammation through an increased infiltration of immune cells [19–21]. In particular, a rise in EAT adipocyte size has been associated with lipid droplet degeneration, the presence of macrophages polarized toward a proinflammatory M1 state, and the local expression of proinflammatory mediators [21]. Although EAT inflammation can increase, the levels of mediators produced locally may not correlate with the corresponding plasma levels [22].

EAT can be a proxy of overall visceral adiposity [23], and since this latter represents a potential source of PCSK9 [22], the present study is aimed at evaluating whether PCSK9 is expressed in EAT and if a correlation with EAT amount and local inflammation, regardless of total circulating levels, can be found. PCSK9 may therefore be ascribed among those bioactive molecules belonging to the EAT secretome affecting vascular homeostasis and heart health.

2. Materials and Methods

2.1. Study Population

A total of 68 patients with coronary artery disease (CAD) or valvular diseases (VR) and 46 control subjects matched for age, sex, and BMI (CTR) were enrolled in the study. Patients were recruited at the IRCCS Policlinico San Donato between October 2012 and July 2016. We followed the methods cited in our present paper by Dozio et al. [24]. We excluded patients with the following criteria: , acute myocardial infarction in the previous month, end-stage heart failure, other heart diseases different from CAD and VR, malignant diseases, major abdominal surgery in the previous six months, renal and liver diseases, chronic inflammatory diseases, more than 3% change in body weight in the previous three months, and missing or incomplete clinical history and data. Among the 68 patients, 32 underwent open heart surgery. Twenty-one required coronary artery bypass surgery (CABG), an elective open heart procedure in hemodynamically stable patients taking their standard cardiac treatments and under the care of the cardiologist, and 11 required valve replacement. EAT samples were collected just from these 32 patients during surgery. Due to the lower amount of tissue isolated during surgery, 22 samples were used for microarray studies and 10 samples for protein expression studies. Blood samples for plasma quantification of PCSK9 were obtained from the total of patients and CTR subjects. Written informed consent was obtained from all participants. The study was approved by the local ethics committee (ASL Milano Due, protocol 2516) and conducted in accordance with the Declaration of Helsinki, as revised in 2013, and Good Clinical Practice guidelines.

2.2. Biochemical Parameters

Blood samples were collected after overnight fasting, into pyrogen-free EDTA tubes or in tubes for serum collection. EDTA plasma samples for nonroutine assays were obtained after centrifugation at 1200 g for 15 min and immediately stored at -20°C until subsequent analyses. A cobas 6000 analyzer and commercial kits (Roche Diagnostics, Milan, Italy) were used for the quantification of routine biochemical parameters, as previously reported [24–27]. LDL-cholesterol was calculated with the Friedewald formula. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated using the following equation: .

2.3. Anthropometric Measures

Weight, height, and waist circumference (WC) were directly measured at hospital admission. Weight and height were recorded to the nearest 0.1 kg and 0.5 cm using standard scales and stadiometers. WC was measured using a flexible tape. Body mass index (BMI) and waist-to-height ratio (WHtR) were then calculated as weight (kg)/height² (m²) and WC (cm)/height (cm), respectively. As defined by WHO, patients were classified as normal weight (BMI 18.5-24.9 kg/m²), overweight (BMI 25.0-29.9 kg/m²), and obese ( kg/m²).

2.4. EAT Thickness Measurement

All patients underwent standard echocardiography using commercially available equipment (Vingmed-System Five; General Electric, Horten, Norway). Briefly, EAT was identified as the echo-free space between the outer wall of the myocardium and the visceral layer of the pericardium. EAT thickness was measured perpendicularly on the free wall of the right ventricle at the end-systole in three cardiac cycles. The parasternal long-axis view allowed for the most accurate measurement of EAT on the right ventricle, with optimal cursor beam orientation in each view. Maximum EAT thickness was measured at the point on the free wall of the right ventricle along the midline of the ultrasound beam, perpendicular to the aortic annulus, used as the anatomical landmark for this view [28]. The average value of three cardiac cycles was calculated and used for analysis.

2.5. EAT Collection

Before starting cardiopulmonary bypass pumping, a sample of EAT adjacent to the proximal right coronary artery was harvested. For RNA and protein expression studies, EAT samples were stored in an Allprotect Tissue Reagent (QIAGEN, Hilden, Germany) at -20°C.

2.6. RNA Extraction and Microarray Analysis

Total RNA was extracted from tissue with the RNeasy Lipid Tissue Kit according to the manufacturer’s procedure (QIAGEN). RNA concentration was quantified by NanoDrop 2000 (Thermo Scientific, Wilmington, Germany), and RNA integrity was assessed using the Agilent RNA 6000 Nano Kit and the Agilent 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA). Gene expression was analysed by a one-color microarray platform (Agilent): 50 ng of total RNA was labeled with Cy3 using the Agilent Low Input Quick Amp Labeling Kit-1 color, according to the manufacturer’s directions. cRNA was purified with the RNeasy Mini Kit (QIAGEN), and the amount and labeling efficiency were measured with NanoDrop. For hybridization, we used an Agilent Gene Expression Hybridization Kit and scanned with the Agilent G2565CA Microarray Scanner System. Data were processed using Agilent Feature Extraction Software (10.7) with the single-color gene expression protocol, and raw data were analyzed with ChipInspector Software (Genomatix, Munich, Germany). In brief, raw data were normalized on the single-probe level based on the array mean intensities, and statistics were calculated based on the SAM algorithm by Tusher et al. [29]. Fold changes were calculated from normalized data.

2.7. PCKS9 Assays (ELISA)

Circulating levels of PCKS9 were measured on EDTA-plasma samples according to the manufacturer’s directions with the PCSK9 Quantikine ELISA Kit (SPC900) from R&D Systems (Minneapolis, MN). The mean minimum detectable dose was 0.096 ng/mL [30]. The maximum intra- and interassay coefficients of variation were 6.5% and 5.9%, respectively.

2.8. Western Blot

EAT samples of heart tissues were homogenized with TissueLyser II (QIAGEN) in an ice-cold RIPA lysis buffer (50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 1% Triton X-100, 0.1% SDS, 0.5% Na-deoxycholate, and 50 mM sodium fluoride) containing 1% protease inhibitor cocktail (Sigma-Aldrich, Milan, Italy). The homogenate was kept on ice for 30 min, centrifuged at 500 rpm for 10 min at 4°C, and the resulting supernatant centrifuged at 13,200 rpm for 15 min at 4°C. Protein concentration was determined with the Quantum Protein Assay Kit, based on a BCA reagent (EuroClone, Milan, Italy). Equal amounts of protein samples (30 μg) were suspended in a Laemmli sample buffer and separated using 4-20% Mini-PROTEAN TGX Stain-Free Gels and a Tris/Glycine/SDS running buffer (Bio-Rad). The separated proteins were then transferred from the gel to a nitrocellulose membrane using the Trans-Blot Turbo Mini Nitrocellulose Transfer Packs and the Trans-Blot Transfer System (Bio-Rad). The membranes were blocked with 5% dry milk in Tris-buffered saline/0.1% Tween 20 for 1 h at room temperature, and the blots were then incubated overnight at 4°C with a diluted solution of the primary anti-PCSK9 antibody (1 : 500) (GeneTex, Alton Pkwy, Irvine, CA, USA). The subsequent incubation with a secondary antibody conjugated with peroxidase (1 : 5000) was performed at room temperature for 2 h. Immunoreactivity was detected by a working solution (Clarity Western ECL Substrate, Bio-Rad) and the ChemiDoc Touch System.

2.9. Statistical Analysis

Quantitative variables are expressed as median and 25th-75th percentiles or . Qualitative variables are summarized as numbers and percentages. The normality of data distribution was assessed with the Kolmogorov-Smirnoff test. Comparison between two groups was performed by -test or Mann-Whitney tests for continuous variables. Fisher’s exact test was used for nominal variables. Relations between parameters were examined with the Spearman correlation test. Data were analyzed using the GraphPad Prism 5.0 biochemical statistical package (GraphPad Software, San Diego, CA). A value < 0.05 was considered significant.

3. Results

3.1. Patient Characteristics

The main demographic, anthropometric, clinical, and biochemical characteristics of patients are shown in Table 1. Mean age (± standard deviation, SD) was years and males were the majority (88.24%). According to the body mass index (BMI), roughly 50% were overweight and 30% obese. EAT thickness ranged from 3 to 12 mm (: mm). Relative to lipid profile, this was in the normal range: total cholesterol mg/dL, LDL-cholesterol (LDL-C) mg/dL, and HDL-C mg/dL. Sixty-seven % (67.65%) were under statin treatment. Out of 68 patients, 48 had a diagnosis of coronary artery disease (CAD) and 11 of valve disease. Thirty-two underwent open heart surgery for coronary bypass grafting (CABG, ) or valvular replacement (VR, ). As shown in Table 1, patients in this subgroup had a lower incidence of diabetes with lower levels of HbA1c.

3.2. PCSK9 Expression in EAT

PCSK9 expression in EAT was evaluated at both the gene and protein levels. PCSK9 gene expression was evaluated by microarray analysis (: arbitrary unit), with the PCSK9 local level being positively correlated with EAT thickness (, ). Since statins increase the PCSK9 levels, PCSK9 gene expression was evaluated in both patients taking and patients not taking statins: no difference has been observed between the two groups () (data not shown). The immunoreactive band of 62-66 kDa confirmed the protein expression of PCSK9 (Figure 1).

3.3. Correlation of PCSK9 Expression with Genes Involved in the Inflammatory Response in EAT

The expression of 142 genes (supplementary Table 1) involved in the inflammatory response in EAT was analyzed and correlated with the PCSK9 levels. Twenty-two genes were found to be directly correlated with PCSK9, especially those encoding for chemokines and chemokine receptors, which exert chemotactic activity for lymphocytes, monocytes, and granulocytes, and interleukins. Names and functions of the genes which correlate with PCSK9 are reported in Table 2.

3.4. Plasma Levels of PCSK9

Plasma levels of PCSK9 were measured in CVD patients and in a group of 29 CTR. PCSK9 was higher in CVD patients than in CTR ( vs. ng/mL, respectively; ) (Figure 2). Among the CVD patients, circulating PCSK9 levels were higher in those given statins ( ng/mL vs. ng/mL; ). EAT thickness was also higher in CVD patients than in CTR ( mm vs. ng/mL; ). Correlation analyses of the plasma PCSK9 levels with PCSK9 expression in EAT and EAT thickness were not statistically significant ().

4. Discussion

In the present study, for the firt time, we have demonstrated that EAT is a source of PCSK9 and that EAT inflammation is associated with local PCSK9 expression, regardless of the circulating PCSK9 levels.

The liaison between PCSK9 and adipose tissue still lacks evidence. It was previously demonstrated that PCSK9 is expressed and secreted by viscaral adipose tissue (VAT) and correlated with BMI [31]. PCSK9 seems to reduce VAT accumulation independently of the LDLR by promoting the degradation of the very-low density lipoprotein receptor (VLDLR) in adipocytes, thereby limiting fatty acid internalization [32, 33]. PCSK9 R46L carriers, compared with noncarriers, have shown increased BMI, a rise in the percentage of total and android fat masses, and a higher EAT thickness. These observations were replicated by the same group in PCSK9 KO mice, that showed an increment in visceral adipose tissue, but not in the subcutaneous ones [32, 33]. Conversely, we observed positive correlations of PCSK9 expression in EAT with EAT amount and local inflammation, but not with the PCSK9 circulating levels. Overall, inflammation may be the main link between EAT enlargement and PCSK9 expression. Indeed, our and other groups found that in CVD patients, EAT is infiltrated by macrophages polarized toward a proinflammatory M1 state and T- and B-lymphocytes and that the local inflammatory status is strongly associated with EAT adipocyte size, EAT amount, and lipid droplet degeneration [21, 34, 35]. Therefore, we can hypothesize that EAT inflammation may upregulate PCSK9 expression which in turn can exert proinflammatory and detrimental effects locally and on tissues lying in contiguity with EAT, such as the myocardium and coronary vessels. The bidirectional association between inflammation and PCSK9 has been previously demonstrated both in vitro and in the animal models [4, 36]. PCSK9 silencing in macrophages can partially reduce oxLDL-induced-cytokine production, with PCSK9 KO mice showing a reduced inflammatory response [37]. PCSK9 stimulates the expression of proinflammatory cytokines after exposure to LPS, and PCSK9 downregulation in atherosclerotic plaques reduces macrophage infiltration and cytokine secretion [7, 37–39]. Although our study did not explore the mechanisms linking inflammation to PCSK9 expression, it confirmed the existence of correlations also in EAT. Looking at the molecules associated with PCSK9 expression, it can be noted that they are mainly chemokines, cytokines, and other molecules involved in chemotaxis, differentiation, and activation of different leukocyte populations as well as proinflammatory mediators that can amplify local inflammation through NF-κB activation. In particular, the association previously observed in vitro between PCSK9 and CXCL2 [7] has been detected in EAT too, thus confirming that PCSK9 can play a role in monocyte recruitment.

The protein expression of PCSK9 in EAT argues that PCSK9 is part of the EAT secretome. Therefore, in addition to increasing local EAT inflammation, PCSK9 derived from EAT may directly affect the coronary vessels and the myocardium, thus increasing CV risk. This amount of EAT-secreted PCSK9 is added to the amount that can be derived from the circulation. The finding that CVD patients have higher plasma PCSK9 levels is in line with previous reports showing PCSK9 to be associated with the Framingham Risk Score [40] or with inflammation in the acute phase and hypercholesterolemia in patients with acute coronary syndrome [41]. In our study, we did not find any association of plasma PCSK9 with local EAT expression and inflammation. Therefore, EAT-derived PCSK9 may play an additional and independent risk to CVD. Recently, it has also been demonstrated that PCSK9 is not only implicated in atherogenesis but can also determine the development of infarct size and affect contractive function of cardiomyocytes [5, 42].

From a clinical point of view, in atherosclerotic plaques, PCSK9 monoclonal antibodies can reduce macrophage content through the reduction of CCR2 expression in monocytes with a consequent impairment in their migratory capacity [43, 44]. Whether this treatment may affect EAT inflammation, its metabolism, and amount is unknown; therefore, additional studies are necessary to demonstrate any potential effect of reduced PCSK9 levels on EAT and EAT-associated CV risk.

It is important to point out that about 50% of our patients were under statin therapy. Statin use is associated with a reduction in EAT thickness and inflammation, supporting the hypothesis of a direct action of statins on the EAT secretory profile [45, 46]. Targeting some inflammatory mediators, such as IL1β, reduces CV events, regardless of LDL-C lowering [47]. Differently, statins may upregulate the expression of PCSK9 via SREBP-2 [48]. Therefore, the PCSK9 levels in EAT may be influenced by the direct effect of statins on its expression and the modulation of local inflammation too. Notably, no rise in PCSK9 protein expression was found in EAT from patients taking statins. However, no data are available relative to the association between modulation of EAT inflammation and PCSK9 levels.

Our study has some limitations. First, the amount of EAT collected during surgery did not allow us to evaluate EAT transcriptomes and proteomes on the same samples. Second, we did not have a surgical control group used to compare PCSK9 and the other genes analyzed. Third, our study group is composed of both CABG and VR patients. Although the mechanisms driving the two pathologies are different, many studies demonstrated the involvement of EAT amount and secretome in the progression of both diseases [14, 49–52]. Fourth, since our study is cross-sectional, our findings cannot imply causality. In conclusion, we provided evidence for the possible role of PCSK9 as an EAT-derived risk factor for CVD. In the clinical setting, reducing both the EAT inflammation and the PCSK9 local levels might have beneficial effect on EAT metabolism and EAT-related CV risk, but this needs further investigations.

Data Availability

The data used to support the findings of this study are available from the corresponding author upon request.

Conflicts of Interest

The authors declare no conflict of interest.

Authors’ Contributions

Elena Dozio and Massimiliano Ruscica contributed equally to this work.

Acknowledgments

The authors thank Judith Baggott for language editing. The study was supported by funding from Fondazione E. A. Fiera Internazionale di Milano to Università degli Studi di Milano and Ricerca Corrente funding from the Italian Ministry of Health to IRCCS Policlinico San Donato.

Supplementary Materials

Supplementary Table 1 describes the list of genes that have been analyzed in the study and correlated with PCSK9 expression in EAT. (Supplementary Materials)

References

C. Macchi, M. Banach, A. Corsini, C. R. Sirtori, N. Ferri, and M. Ruscica, “Changes in circulating pro-protein convertase subtilisin/kexin type 9 levels - experimental and clinical approaches with lipid-lowering agents,” European Journal of Preventive Cardiology, vol. 26, pp. 930–949, 2018.
View at: Google Scholar
N. Ferri, A. Corsini, C. Macchi, P. Magni, and M. Ruscica, “Proprotein convertase subtilisin kexin type 9 and high-density lipoprotein metabolism: experimental animal models and clinical evidence,” Translational Research, vol. 173, pp. 19–29, 2016.
View at: Publisher Site | Google Scholar
G. D. Norata, H. Tavori, A. Pirillo, S. Fazio, and A. L. Catapano, “Biology of proprotein convertase subtilisin kexin 9: beyond low-density lipoprotein cholesterol lowering,” Cardiovascular Research, vol. 112, no. 1, pp. 429–442, 2016.
View at: Publisher Site | Google Scholar
A. A. Momtazi-Borojeni, S. Sabouri-Rad, A. M. Gotto Jr. et al., “PCSK9 and inflammation: a review of experimental and clinical evidence,” European Heart Journal - Cardiovascular Pharmacotherapy, vol. 5, no. 4, pp. 237–245, 2019.
View at: Publisher Site | Google Scholar
Z. Ding, X. Wang, S. Liu et al., “PCSK9 expression in the ischaemic heart and its relationship to infarct size, cardiac function, and development of autophagy,” Cardiovascular Research, vol. 114, no. 13, pp. 1738–1751, 2018.
View at: Publisher Site | Google Scholar
M. Camera, L. Rossetti, S. S. Barbieri et al., “PCSK9 as a positive modulator of platelet activation,” Journal of the American College of Cardiology, vol. 71, no. 8, pp. 952–954, 2018.
View at: Publisher Site | Google Scholar
C. Ricci, M. Ruscica, M. Camera et al., “PCSK9 induces a pro-inflammatory response in macrophages,” Scientific Reports, vol. 8, no. 1, p. 2267, 2018.
View at: Publisher Site | Google Scholar
C. Cercato and F. A. Fonseca, “Cardiovascular risk and obesity,” Diabetology and Metabolic Syndrome, vol. 11, no. 1, 2019.
View at: Publisher Site | Google Scholar
V. Parisi, V. D’Esposito, F. Passaretti et al., “Epicardial fat tissue: a potential role in aortic stenosis pathogenesis,” Journal of the American College of Cardiology, vol. 63, no. 12, pp. A2021–A2021, 2014.
View at: Publisher Site | Google Scholar
A. A. Mahabadi, H. A. Kahlert, I. Dykun, B. Balcer, P. Kahlert, and T. Rassaf, “Epicardial adipose tissue thickness independently predicts severe aortic valve stenosis,” The Journal of Heart Valve Disease, vol. 26, no. 3, pp. 262–267, 2017.
View at: Google Scholar
N. Nerlekar, A. J. Brown, R. G. Muthalaly et al., “Association of epicardial adipose tissue and high-risk plaque characteristics: a systematic review and meta-analysis,” Journal of the American Heart Association, vol. 6, no. 8, 2017.
View at: Publisher Site | Google Scholar
K. E. Koepp, M. Obokata, Y. N. Reddy, T. P. Olson, and B. A. Borlaug, “Impact of epicardial adipose tissue in heart failure with preserved ejection fraction,” Journal of Cardiac Failure, vol. 24, no. 8, pp. S4–S4, 2018.
View at: Publisher Site | Google Scholar
A. C. T. Ng, M. Strudwick, R. J. van der Geest et al., “Impact of epicardial adipose tissue, left ventricular myocardial fat content, and interstitial fibrosis on myocardial contractile function,” Circulation. Cardiovascular Imaging, vol. 11, no. 8, p. e007372, 2018.
View at: Publisher Site | Google Scholar
E. Vianello, M. Marrocco-Trischitta Massimiliano, E. Dozio et al., “Correlational study on altered epicardial adipose tissue as a stratification risk factor for valve disease progression through IL-13 signaling,” Journal of Molecular and Cellular Cardiology, vol. 132, pp. 210–218, 2019.
View at: Publisher Site | Google Scholar
E. Vianello, E. Dozio, F. Bandera et al., “Dysfunctional EAT thickness may promote maladaptive heart remodeling in CVD patients through the ST2-IL33 system, directly related to EPAC protein expression,” Scientific Reports, vol. 9, no. 1, p. 10331, 2019.
View at: Publisher Site | Google Scholar
E. Vianello, E. Dozio, F. Bandera et al., “Correlative study on impaired prostaglandin E2 regulation in epicardial adipose tissue and its role in maladaptive cardiac remodeling via EPAC2 and ST2 signaling in overweight cardiovascular disease subjects,” International Journal of Molecular Sciences, vol. 21, no. 2, p. 520, 2020.
View at: Publisher Site | Google Scholar
G. Iacobellis, A. E. Malavazos, and M. M. Corsi, “Epicardial fat: from the biomolecular aspects to the clinical practice,” The International Journal of Biochemistry & Cell Biology, vol. 43, no. 12, pp. 1651–1654, 2011.
View at: Publisher Site | Google Scholar
A. C. Villasante Fricke and G. Iacobellis, “Epicardial adipose tissue: clinical biomarker of cardio-metabolic risk,” International Journal of Molecular Sciences, vol. 20, no. 23, p. 5989, 2019.
View at: Publisher Site | Google Scholar
T. Mazurek, L. F. Zhang, A. Zalewski et al., “Human epicardial adipose tissue is a source of inflammatory mediators,” Circulation, vol. 108, no. 20, pp. 2460–2466, 2003.
View at: Publisher Site | Google Scholar
Y. Hirata, M. Tabata, H. Kurobe et al., “Coronary atherosclerosis is associated with macrophage polarization in epicardial adipose tissue,” Journal of the American College of Cardiology, vol. 58, no. 3, pp. 248–255, 2011.
View at: Publisher Site | Google Scholar
E. Vianello, E. Dozio, F. Arnaboldi et al., “Epicardial adipocyte hypertrophy: association with M1-polarization and toll-like receptor pathways in coronary artery disease patients,” Nutrition, Metabolism, and Cardiovascular Diseases, vol. 26, no. 3, pp. 246–253, 2016.
View at: Publisher Site | Google Scholar
J. S. Yudkin, E. Eringa, and C. D. A. Stehouwer, ““Vasocrine” signalling from perivascular fat: a mechanism linking insulin resistance to vascular disease,” Lancet, vol. 365, no. 9473, pp. 1817–1820, 2005.
View at: Publisher Site | Google Scholar
G. Iacobellis, “Local and systemic effects of the multifaceted epicardial adipose tissue depot,” Nature Reviews. Endocrinology, vol. 11, no. 6, pp. 363–371, 2015.
View at: Publisher Site | Google Scholar
E. Dozio, E. Vianello, A. E. Malavazos et al., “Epicardial adipose tissue GLP-1 receptor is associated with genes involved in fatty acid oxidation and white-to-brown fat differentiation: a target to modulate cardiovascular risk?” International Journal of Cardiology, vol. 292, pp. 218–224, 2019.
View at: Publisher Site | Google Scholar
E. Dozio, A. E. Malavazos, E. Vianello et al., “Interleukin-15 and soluble interleukin-15 receptor α in coronary artery disease patients: association with epicardial fat and indices of adipose tissue distribution,” PLoS One, vol. 9, no. 3, 2014.
View at: Publisher Site | Google Scholar
E. Dozio, S. Briganti, E. Vianello et al., “Epicardial adipose tissue inflammation is related to vitamin D deficiency in patients affected by coronary artery disease,” Nutrition, Metabolism, and Cardiovascular Diseases, vol. 25, no. 3, pp. 267–273, 2015.
View at: Publisher Site | Google Scholar
S. Benedini, E. Dozio, P. L. Invernizzi et al., “Irisin: A Potential Link between Physical Exercise and Metabolism—An Observational Study in Differently Trained Subjects, from Elite Athletes to Sedentary People,” Journal Diabetes Research, vol. 2017, article 1039161, 7 pages, 2017.
View at: Publisher Site | Google Scholar
G. Iacobellis, F. Assael, M. C. Ribaudo et al., “Epicardial fat from echocardiography: a new method for visceral adipose tissue prediction,” Obesity Research, vol. 11, no. 2, pp. 304–310, 2003.
View at: Publisher Site | Google Scholar
V. G. Tusher, R. Tibshirani, and G. Chu, “Significance analysis of microarrays applied to the ionizing radiation response,” Proceedings of the National Academy of Sciences of the United States of America, vol. 98, no. 9, pp. 5116–5121, 2001.
View at: Publisher Site | Google Scholar
M. Ruscica, N. Ferri, F. Fogacci et al., “Circulating levels of proprotein convertase subtilisin/kexin type 9 and arterial stiffness in a large population sample: data from the Brisighella Heart Study,” Journal of the American Heart Association, vol. 6, no. 5, 2017.
View at: Publisher Site | Google Scholar
M. Bordicchia, F. Spannella, G. Ferretti et al., “PCSK9 is expressed in human visceral adipose tissue and regulated by insulin and cardiac natriuretic peptides,” International Journal of Molecular Sciences, vol. 20, no. 2, p. 245, 2019.
View at: Publisher Site | Google Scholar
A. Roubtsova, M. N. Munkonda, Z. Awan et al., “Circulating proprotein convertase subtilisin/kexin 9 (PCSK9) regulates VLDLR protein and triglyceride accumulation in visceral adipose tissue,” Arteriosclerosis, Thrombosis, and Vascular Biology, vol. 31, no. 4, pp. 785–791, 2011.
View at: Publisher Site | Google Scholar
A. Baragetti, G. Balzarotti, L. Grigore et al., “PCSK9 deficiency results in increased ectopic fat accumulation in experimental models and in humans,” European Journal of Preventive Cardiology, vol. 24, no. 17, pp. 1870–1877, 2017.
View at: Publisher Site | Google Scholar
V. Miksztowicz, C. Morales, M. Barchuk et al., “Metalloproteinase 2 and 9 activity increase in epicardial adipose tissue of patients with coronary artery disease,” Current Vascular Pharmacology, vol. 15, no. 2, pp. 135–143, 2017.
View at: Publisher Site | Google Scholar
M. Horckmans, M. Bianchini, D. Santovito et al., “Pericardial adipose tissue regulates granulopoiesis, fibrosis, and cardiac function after myocardial infarction,” Circulation, vol. 137, no. 9, pp. 948–960, 2018.
View at: Publisher Site | Google Scholar
M. Ruscica, L. Tokgozoglu, A. Corsini, and C. R. Sirtori, “PCSK9 inhibition and inflammation: a narrative review,” Atherosclerosis, vol. 288, pp. 146–155, 2019.
View at: Publisher Site | Google Scholar
K. R. Walley, K. R. Thain, J. A. Russell et al., “PCSK9 is a critical regulator of the innate immune response and septic shock outcome,” Science Translational Medicine, vol. 6, no. 258, p. 258ra143, 2014.
View at: Publisher Site | Google Scholar
Z. Tang, L. Jiang, J. Peng et al., “PCSK9 siRNA suppresses the inflammatory response induced by oxLDL through inhibition of NF-κB activation in THP-1-derived macrophages,” International Journal of Molecular Medicine, vol. 30, no. 4, pp. 931–938, 2012.
View at: Publisher Site | Google Scholar
Z. H. Tang, J. Peng, Z. Ren et al., “New role of PCSK9 in atherosclerotic inflammation promotion involving the TLR4/NF-κB pathway,” Atherosclerosis, vol. 262, pp. 113–122, 2017.
View at: Publisher Site | Google Scholar
C. Macchi, N. Ferri, C. Favero et al., “Long-term exposure to air pollution raises circulating levels of proprotein convertase subtilisin/kexin type 9 in obese individuals,” European Journal of Preventive Cardiology, vol. 26, no. 6, pp. 578–588, 2018.
View at: Publisher Site | Google Scholar
B. Gencer, F. Montecucco, D. Nanchen et al., “Prognostic value of PCSK9 levels in patients with acute coronary syndromes,” European Heart Journal, vol. 37, no. 6, pp. 546–553, 2016.
View at: Publisher Site | Google Scholar
K. D. Schluter, A. Wolf, M. Weber, R. Schreckenberg, and R. Schulz, “Oxidized low-density lipoprotein (oxLDL) affects load-free cell shortening of cardiomyocytes in a proprotein convertase subtilisin/kexin 9 (PCSK9)-dependent way,” Basic Research in Cardiology, vol. 112, no. 6, p. 63, 2017.
View at: Publisher Site | Google Scholar
S. Kühnast, J. W. A. van der Hoorn, E. J. Pieterman et al., “Alirocumab inhibits atherosclerosis, improves the plaque morphology, and enhances the effects of a statin,” Journal of Lipid Research, vol. 55, no. 10, pp. 2103–2112, 2014.
View at: Publisher Site | Google Scholar
S. J. Bernelot Moens, A. E. Neele, J. Kroon et al., “PCSK9 monoclonal antibodies reverse the pro-inflammatory profile of monocytes in familial hypercholesterolaemia,” European Heart Journal, vol. 38, no. 20, pp. 1584–1593, 2017.
View at: Publisher Site | Google Scholar
P. Raggi, V. Gadiyaram, C. Zhang, Z. Chen, G. Lopaschuk, and A. E. Stillman, “Statins reduce epicardial adipose tissue attenuation independent of lipid lowering: a potential pleiotropic effect,” Journal of the American Heart Association, vol. 8, no. 12, 2019.
View at: Publisher Site | Google Scholar
V. Parisi, L. Petraglia, V. D'Esposito et al., “Statin therapy modulates thickness and inflammatory profile of human epicardial adipose tissue,” International Journal of Cardiology, vol. 274, pp. 326–330, 2019.
View at: Publisher Site | Google Scholar
P. M. Ridker, B. M. Everett, T. Thuren et al., “Antiinflammatory therapy with canakinumab for atherosclerotic disease,” The New England Journal of Medicine, vol. 377, no. 12, pp. 1119–1131, 2017.
View at: Publisher Site | Google Scholar
T. Nozue, “Lipid lowering therapy and circulating PCSK9 concentration,” Journal of Atherosclerosis and Thrombosis, vol. 24, no. 9, pp. 895–907, 2017.
View at: Publisher Site | Google Scholar
T. S. Alnabelsi, Y. Alhamshari, R. H. Mulki et al., “Relation between epicardial adipose and aortic valve and mitral annular calcium determined by computed tomography in subjects aged ≥65 years,” The American Journal of Cardiology, vol. 118, no. 7, pp. 1088–1093, 2016.
View at: Publisher Site | Google Scholar
A. S. Antonopoulos and C. Antoniades, “The role of epicardial adipose tissue in cardiac biology: classic concepts and emerging roles,” The Journal of Physiology, vol. 595, no. 12, pp. 3907–3917, 2017.
View at: Publisher Site | Google Scholar
B. Verma, D. Katyal, A. Patel, V. R. Singh, and S. Kumar, “Relation of systolic and diastolic epicardial adipose tissue thickness with presence and severity of coronary artery disease (the EAT CAD study),” Journal of Family Medicine and Primary Care, vol. 8, no. 4, pp. 1470–1475, 2019.
View at: Publisher Site | Google Scholar
L. Davin, A. Nchimi, F. Ilardi et al., “Epicardial adipose tissue and myocardial fibrosis in aortic stenosis relationship with symptoms and outcomes: a study using cardiac magnetic resonance imaging,” JACC: Cardiovascular Imaging, vol. 12, no. 1, pp. 213-214, 2019.
View at: Publisher Site | Google Scholar

Copyright

Copyright © 2020 Elena Dozio et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

PDF Download Citation

Download other formats

Order printed copies

Views

926

Downloads

913

Citations