Prior endurance exercise prevents postprandial lipaemia‐induced increases in reactive oxygen species in circulating CD31⁺ cells

Abstract

Non-technical summary Circulating angiogenic cells (CACs) repair and maintain the vascular endothelium. CACs are responsive to lifestyle factors such as diet and physical activity. For example, their capacity to regenerate the endothelium is impaired in cardiovascular disease patients, whereas exercise training can improve CAC function. In this study, we examined the effects of a high-fat meal with and without prior endurance exercise on several molecular aspects of CAC function, including levels of reactive oxygen species (ROS), nitric oxide (NO), intracellular lipids, and gene expression. Our results indicated that the high-fat meal induced significant oxidative stress (i.e. ROS production) in the CACs that expressed the cell surface protein CD31. However, when subjects performed a single bout of exercise on the prior day, the meal had no effect on ROS in CD31 + cells. Therefore, we concluded that prior exercise prevents the oxidative stress induced by a high-fat meal in CD31 + CACs.Abstract We hypothesized that prior exercise would prevent postprandial lipaemia (PPL)-induced increases in intracellular reactive oxygen species (ROS) in three distinct circulating angiogenic cell (CAC) subpopulations. CD34 + , CD31 + /CD14 − /CD34 − , and CD31 + /CD14 + /CD34 − CACs were isolated from blood samples obtained from 10 healthy men before and 4 h after ingesting a high fat meal with or without ∼50 min of prior endurance exercise. Significant PPL-induced increases in ROS production in both sets of CD31 + cells were abolished by prior exercise. Experimental ex vivo inhibition of NADPH oxidase activity and mitochondrial ROS production indicated that mitochondria were the primary source of PPL-induced oxidative stress. The attenuated increases in ROS with prior exercise were associated with increased antioxidant gene expression in CD31 + /CD14 − /CD34 − cells and reduced intracellular lipid uptake in CD31 + /CD14 + /CD34 − cells. These findings were associated with systemic cardiovascular benefits of exercise, as serum triglyceride, oxidized low density lipoprotein-cholesterol, and plasma endothelial microparticle concentrations were lower in the prior exercise trial than the control trial. In conclusion, prior exercise completely prevents PPL-induced increases in ROS in CD31 + /CD14 − /CD34 − and CD31 + /CD14 + /CD34 − cells. The mechanisms underlying the effects of exercise on CAC function appear to vary among specific CAC types.

Short-term exercise training improves flow-mediated dilation and circulating angiogenic cell number in older sedentary adults

“…The CD34+ fraction was purified using 2 rounds of immunomagnetic cell separation according to the manufacturer’s instructions (EasySep Immunomagnetic Cell Separation Kits, STEMCELL Technologies) using an antibody specific for CD34. This isolation approach has been published previously from our laboratory (Jenkins et al 2011 a , 2011 b ; Landers-Ramos et al 2015) and results in ~50% purity of the cell populations from nonmobilized blood, which is equivalent to or greater than other published purity results (Asahara 1997; Schatteman et al 2000; Awad 2006). The validity of the CD34+ PBMC immunomagnetic selection procedure has been previously confirmed in our laboratory via fluorescent activated cell sorting analyses and confirmed via messenger RNA (mRNA) expression (Jenkins et al 2011 a , 2011 b ; Landers-Ramos et al 2015) as positively selected CD34+ cells displayed strong expression of the target antigens with minimal presence of the target in the negative fractions (data not shown).…”

“…CD34+ was selected as the cell type on which to perform intracellular measures based on the following: frequency of this cell type within total PBMCs, previous work in our lab supporting the use of similar intracellular measures in the same cell type (Jenkins et al 2011 a , 2011 b ), and literature identifying cells with the CD34 marker as progenitor cells with angiogenic properties (Schatteman et al 2000; Harraz et al 2001; Awad 2006; Mackie and Losordo 2011; Losordo et al 2011). The CD34+ fraction was purified using 2 rounds of immunomagnetic cell separation according to the manufacturer’s instructions (EasySep Immunomagnetic Cell Separation Kits, STEMCELL Technologies) using an antibody specific for CD34.…”

Dynamic microvesicle release and clearance within the cardiovascular system: triggers and mechanisms

“…Harrison et al [80] also noted elevated CD31 + CD42b − endothelial MVs following a high-fat meal. This effect appears to last for only the first few hours after ingestion of fatty foods, as no change in either CD31 + CD42 − or CD62E + endothelial-cellderived MVs was evident 4 hours following ingestion of a highfat meal in ten healthy men [81]. Tushuizen et al [82] found that two high-fat meals in one day led to increased levels of total MVs, but not endothelial-cell-specific MVs, in the circulation, along with impaired flow-mediated dilatation in healthy individuals.…”

“…↑ CD31+CD42b-endothelial MVs in 8 healthy males [80] High fat meal (4 hours post) No change in CD31+CD42-or CD62E+ endothelial MVs in 10 healthy males [81] 2 x High fat meal (2 hours post) ↑ Total MVs in 17 healthy males [82] High fat meal (1 and 2 hours post) ↑ Total and endothelial MVs in 10 healthy males [83] They found that platelet, endothelial cell and erythrocyte MVs measured by flow cytometry and a coagulation assay are increased during cardiac stress in those with normal stress responses, but not in those with vascular disease [96]. Exercise-and dobutamineinduced stress both cause increased heart rate and can induce hypoxia as well as increased vascular shear stress.…”

The role of oxidative stress in postprandial endothelial dysfunction

“…It is noteworthy that the addition of antioxidants in the aforementioned studies did not influence the magnitude of postprandial TAG excursion. As such, their protective effects do not appear to be due to effects on TAG (86) and 2010) (82) HS ( (117) HS (n 10) 30 g SFA; 84% E 0·68 " ROS, oxLDL and SOD ¼ EMP No significant correlation found metabolism. Rather, they appear to attenuate postprandial hypertriacylglycerolaemia-induced oxidative stress in response to a HSFAM, resulting in lesser endothelial damage.…”