Obesity suppresses circulating level and function of endothelial progenitor cells and heart function

Abstract

Background and aim: This study tested the hypothesis that obesity suppresses circulating number as well as the function of endothelial progenitor cells (EPCs) and left ventricular ejection fraction (LVEF).Methods: High fat diet (45 Kcal% fat) was given to 8-week-old C57BL/6 J mice (n = 8) for 20 weeks to induce obesity (group 1). Another age-matched group (n = 8) were fed with control diet for 20 weeks as controls (group 2). The animals were sacrificed at the end of 20 weeks after obesity induction.Results: By the end of study period, the heart weight, body weight, abdominal fat weight, serum levels of total cholesterol and fasting blood sugar were remarkably higher in group 1 than in group 2 (all p<0.01). The circulating level of EPCs (C-kit/CD31, Sca-1/KDR, CXCR4/CD34) was significantly lower in group 1 than in group 2 (p<0.03) at 18 h after critical limb ischemia induction. The angiogenesis and migratory ability of bone marrow-derived EPCs was remarkably impaired in group 1 compared to that in group 2 (all p<0.01). The repair ability of aortic endothelium damage by lipopolysaccharide was notably attenuated in group 1 compared with that in group 2 (p<0.01). Collagen deposition (Sirius red staining) and fibrotic area (Masson's Trichrome staining) in LV myocardium were notably increased in group 1 compared with group 2 (p<0.001). LVEF was notably lower, whereas LV end-diastolic and end-systolic dimensions were remarkably higher in group 1 than in group 2 (all p<0.001).Conclusions: Obesity diminished circulating EPC level, impaired the recovery of damaged endothelium, suppressed EPC angiogenesis ability and LVEF, and increased LV remodeling. © 2012 Tsai et al.; licensee BioMed Central Ltd.