Open AccessGenome‐wide epigenetic and proteomic analysis reveals altered Notch signaling in EPC dysfunction
Author(s) -
Karcher Jamie R.,
Hoffmann Brian R.,
Liu Pengyuan,
Liu Yong,
Liang Mingyu,
Greene Andrew S.
Publication year - 2015
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12358
Subject(s) - angiogenesis , progenitor cell , cd34 , dna methylation , endothelial progenitor cell , notch signaling pathway , in vivo , epigenetics , bone marrow , microbiology and biotechnology , biology , methylation , cancer research , chemistry , stem cell , signal transduction , gene expression , immunology , gene , genetics
Endothelial progenitor cells ( EPC s) are bone‐marrow‐derived mononuclear cells that participate in tube formation in vitro and vessel formation in vivo. EPC transplantation, as a therapeutic approach in cardiovascular diseases, has produced mixed results likely due to underlying disease states and environmental factors affecting EPC function. In this study, we investigated the mechanisms by which a high‐salt diet impairs EPC function. The number of endothelial progenitor cells ( CD 34 + , VEGFR 2 + , CD 133 + , and c‐Kit + ) was decreased in the bone marrow of Sprague–Dawley ( SD ) rats fed a high‐salt diet ( HSD ; 4% NaCl) as compared to SD rats on a normal‐salt diet ( NSD ; 0.4% NaCl). NSD EPC s augmented endothelial cell tube formation in vitro, whereas HSD EPC s did not. NSD EPC s were a potent therapeutic restoring electrical stimulation‐induced angiogenesis in vivo. HSD EPC s were not able to restore angiogenesis in vivo. EPC DNA methylation was analyzed by reduced representative bisulfite sequencing and membrane proteins were analyzed using high accuracy liquid chromatography mass spectrometry. Differentially methylated genes and differentially abundant membrane proteins measured between the NSD and HSD EPC s, revealed a total of 886 gene‐protein sets where reciprocal methylation and expression occurred. Based on stringent criteria, Notch4 was found to be hypermethylated in HSD EPC s and had corresponding decrease in protein expression. Suppression of Notch4 protein expression in EPC s using si RNA confirmed a role for Notch4 in EPC ‐mediated angiogenesis, suggesting Notch4 suppression as a mechanism by which high‐salt diet inhibits EPC ‐mediated angiogenesis.