E Vianello1, E Dozio2, F Arnaboldi2, M G Marazzi2, C Martinelli2, J Lamont3, L Tacchini2, A Sigrüner4, G Schmitz4, M M Corsi Romanelli5. 1. Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy. Electronic address: elena.vianello@unimi.it. 2. Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy. 3. Randox Laboratories LTD, R&D, Crumlin-Antrim, Belfast, Northern Ireland, UK. 4. Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany. 5. Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy; SMEL-1 Clinical Pathology, I.R.C.C.S. Policlinico San Donato, Milan, Italy.
Abstract
BACKGROUND AND AIMS: In coronary artery disease (CAD) epicardial adipose tissue (EAT) shows an elevated inflammatory infiltrate. Toll-like receptors (TLRs) are important mediators of adipose tissue inflammation and they are able to recognize endogenous products released by damaged cells. Because adipocyte death may be driven by hypertrophy, our aim was to investigate in CAD and non-CAD patients the association between EAT adipocyte size, macrophage infiltration/polarization and TLR-2 and TLR-4 expression. METHODS AND RESULTS: EAT biopsies were collected from CAD and non-CAD patients. The adipocyte size was determined by morphometric analysis. Microarray technology was used for gene expression analysis; macrophage phenotype and TLRs expression were analyzed by immunofluorescence and immunohistochemical techniques. Inflammatory mediator levels were determined by immunoassays. EAT adipocytes were larger in CAD than non-CAD patients and do not express perilipin A, a marker of lipid droplet integrity. In CAD, EAT is more infiltrated by CD68-positive cells which are polarized toward an M1 state (CD11c positive) and presents an increased pro-inflammatory profile. Both TLR-2 and TLR-4 expression is higher in EAT from CAD and observed on all the CD68-positive cells. CONCLUSIONS: Our findings suggested that EAT hypertrophy in CAD promotes adipocyte degeneration and drives local inflammation through increased infiltration of macrophages which are mainly polarized towards an M1 state and express both TLR-2 and TLR-4.
BACKGROUND AND AIMS: In coronary artery disease (CAD) epicardial adipose tissue (EAT) shows an elevated inflammatory infiltrate. Toll-like receptors (TLRs) are important mediators of adipose tissue inflammation and they are able to recognize endogenous products released by damaged cells. Because adipocyte death may be driven by hypertrophy, our aim was to investigate in CAD and non-CAD patients the association between EAT adipocyte size, macrophage infiltration/polarization and TLR-2 and TLR-4 expression. METHODS AND RESULTS: EAT biopsies were collected from CAD and non-CAD patients. The adipocyte size was determined by morphometric analysis. Microarray technology was used for gene expression analysis; macrophage phenotype and TLRs expression were analyzed by immunofluorescence and immunohistochemical techniques. Inflammatory mediator levels were determined by immunoassays. EAT adipocytes were larger in CAD than non-CAD patients and do not express perilipin A, a marker of lipid droplet integrity. In CAD, EAT is more infiltrated by CD68-positive cells which are polarized toward an M1 state (CD11c positive) and presents an increased pro-inflammatory profile. Both TLR-2 and TLR-4 expression is higher in EAT from CAD and observed on all the CD68-positive cells. CONCLUSIONS: Our findings suggested that EAT hypertrophy in CAD promotes adipocyte degeneration and drives local inflammation through increased infiltration of macrophages which are mainly polarized towards an M1 state and express both TLR-2 and TLR-4.
Authors: K Rozsívalová; A Pierzynová; H Kratochvílová; J Lindner; M Lipš; T Kotulák; P Ivák; I Netuka; M Haluzík; T Kučera Journal: Physiol Res Date: 2020-06-25 Impact factor: 1.881
Authors: Timothy P Fitzgibbons; Nancy Lee; Khanh-Van Tran; Sara Nicoloro; Mark Kelly; Stanley Kc Tam; Michael P Czech Journal: JCI Insight Date: 2019-10-17