P0717EPIGENETIC REGULATION OF CHRONIC KIDNEY DISEASE ACCELERATED-ATHEROSCLEROSIS
Authors: Doladé Nuria , Rayego-Mateos Sandra , García-Carrasco Alicia , Pérez-Gomez Aurora , Crespo-Masip Maria , Guerin Maryse , Tharaux Pierre-Louis , Valdivielso José M 
Published: June 2020

Abstract

Background and Aims
Atherosclerosis and its related clinical complications are the leading causes of death in western countries. Multiple processes are involved in atherosclerosis like endothelial dysfunction, inflammation, vascular proliferation, neovascularization, oxidative stress, apoptosis, extracellular matrix degradation and thrombosis. Moreover atherosclerosis could be accelerated in some diseases like chronic kidney disease (CKD). In this regard, miRNAs have been elucidated as important factors in the regulation of different cellular and molecular processes involved in atherosclerosis development. Our aim is to identify specific miRNAs that could be involved in chronic kidney disease (CKD) accelerated-atherosclerosis.

Method
A CKD accelerated-atherosclerosis mouse model was developed by subtotal nephrectomy (5/6 nephrectomy) in APOE-/- mice fed on a high fat diet (HFD) during 10 weeks and compared to mice with normal renal function. Urine and blood samples were collected every week. Western-blot, RT-PCR, immunohistochemistry and confocal microscopy analysis were performed. In previous studies mir23a-3p and miR652-3p have been suggested as possible regulators of the atherosclerotic process. Therefore the expression levels of these miRNAs and its possible target genes (FER and BTLA) were analyzed in mice total blood.

Results
APOE-/-+ERC+HFD mouse showed a progressive decrease in renal function and an increase of renal damage markers such as KIM-1. These animals showed structural glomerular damage characterized by de-cellularization, mesangial cell expansion and podocyte (WT1+,podocalixin+), endothelial (CD31+) and mesangial (GATA3+) loss. Lipid profile modifications were also observed in APOE-/-+ERC+HFD mice with an increase in plasma total cholesterol levels. Moreover atherosclerotic plaque size was also increased in APOE-/-+ERC+HFD animals in comparison with atherosclerotic plaque size of APOE-/-+HFD mice. CKD mice showed lower fibrosis (sirius red staining) and higher inflammatory markers in its atherosclerotic plaques. The presence of macrophages (CD68+) and T lymphocytes (CD3+) was increased in APOE-/-+ERC+HFD group in contrast with APOE-/-+HFD animals. Moreover, in samples from the aortic arch of APOE-/-+ERC+HFD mice, ICAM1 protein levels were increased. Finally we found decreased levels of mir23a-3p and mir652-3p gene in total blood samples of APOE-/-+ ERC+ HFD mice. On the other hand, in aortic arc and descendent aorta tissues, mir23a-3p and mir652-3p expression levels were similar between groups. The expression levels of mRNAs of potential targets of this miRNAs (FER and BTLA) were increased in total blood and aortic arch samples. In addition, we observed that BTLA and FER expression were localized in vascular smooth muscle cells and endothelial cells respectively.

Conclusion
Levels of mir23a-3p, mir652-3p and its related mRNA (FER and BTLA) are altered in CKD and may be a potential therapeutic target for CKD-accelerated atherosclerosis treatment.