Race and sex differences in ROS production and SOD activity in HUVECs.

Black individuals and men are predisposed to an earlier onset and higher prevalence of hypertension, compared with White individuals and women, respectively. Therefore, the influence of race and sex on reactive oxygen species (ROS) production and superoxide dismutase (SOD) activity following induced inflammation was evaluated in female and male human umbilical vein endothelial cells (HUVECs) from Black and White individuals. It was hypothesized that HUVECs from Black individuals and male HUVECs would exhibit greater ROS production and impaired SOD activity. Inflammation was induced in HUVEC cell lines (n = 4/group) using tumor necrosis factor-alpha (TNF-α, 50ng/ml). There were no between group differences in ROS production or SOD activity in HUVECs from Black and White individuals, and HUVECs from Black individuals exhibited similar SOD activity at 24hr compared with 4hr of TNF-α treatment (p>0.05). However, HUVECs from White individuals exhibited significantly greater SOD Activity (p<0.05) at 24hr as compared to 4hr in the control condition but not with TNF-α treatment (p>0.05). Female HUVECs exhibited significantly lower ROS production than male HUVECs in the control condition and following TNF-α induced inflammation (p<0.05). Only female HUVECs exhibited significant increases in SOD activity with increased exposure time to TNF-α induced inflammation (p<0.05). HUVECs from White individuals alone exhibit blunted SOD activity when comparing control and TNF-α conditions. Further, compared to female HUVECs, male HUVECs exhibit a pro-inflammatory state.

CD31+ Circulating Angiogenic Cell Number and Subtypes are Reduced in Individuals with Chronic Stroke.

BACKGROUND AND PURPOSE: Reduced number and function of CD31+ circulating angiogenic cells (CACs) may explain vascular complications associated with the chronic phase stroke. The purpose of this study was to quantify CD31+ CAC paracrine function, total number and number of various subtypes of CD31+ CACs in individuals with chronic stroke compared with controls. METHODS: Peripheral blood mononuclear cells were isolated from chronic stroke participants and controls. CD31+ cells were quantified by flow cytometry, as was co-expression of CD31 in combination with CD14, CD3, CD11b, or CD34. Immunomagnetically selected CD31+ cells were cultured, and conditioned medium was used in a capillary-like network assay. RESULTS: Significantly lower levels of CD31+ CACs were found in stroke participants compared with controls (-24%; P=0.04). Additionally, CD31+/CD14+, CD31+/CD11b+ and CD31+/CD3+ cells were significantly lower in the chronic stroke group compared with controls (-45%, P=0.02; -47%, P=0.02 and -32%, P=0.03, respectively). There was no group effect on CD31+ CAC conditioned media-mediated capillary-like network formation. CONCLUSION: CD31+ CACs and subtypes may serve as potential therapeutic targets in chronic stroke recovery.

Effects of Exercise Training on the Paracrine Function of Circulating Angiogenic Cells.

Exercise training has various benefits on cardiovascular health, and circulating angiogenic cells have been proposed as executing these changes. Work from the late 1990s supported an important role of these circulating post-natal cells in contributing to the maintenance and repair of the endothelium and vasculature. It was later found that circulating angiogenic cells were a heterogenous population of cells and primarily functioned in a paracrine manner by adhering to damaged endothelium and releasing growth factors. Many studies have discovered novel circulating angiogenic cell secreted proteins, microRNA and extracellular vesicles that mediate their angiogenic potential, and some studies have shown that both acute and chronic aerobic exercise training have distinct benefits. This review highlights work establishing an essential role of secreted factors from circulating angiogenic cells and summarizes studies regarding the effects of exercise training on these factors. Finally, we highlight the various gaps in the literature in hopes of guiding future work.