Circulating angiogenic cell population responses to 10 days of reduced physical activity

Abstract

Circulating angiogenic cells (CACs) are a diverse group that have been identified as predictors of cardiovascular health and are inversely proportional to cardiovascular disease (CVD) outcomes. Inactivity is a growing concern in industrialized nations and is an independent risk factor for CVD. There is limited evidence regarding the impact of reduced physical activity (rPA) on different CAC populations. The purpose of this study was to evaluate the effect of objectively monitored rPA with maintained energy balance on two CAC populations (CFU and CD34(+) cells), intracellular nitric oxide (NOi), and genes related to NO production in active, healthy men. Participants (age 25 ± 2.9 yr) refrained from structured physical activity for 10 days, which was reflected by a significant reduction in time in vigorous + very vigorous intensity activity (P = 0.03). Sedentary time tended to increase (P = 0.06) with rPA. CFU CACs have been characterized as mainly monocytic and lymphocytic cells. We found significant reductions in both the number of CFU CACs (-35.69%, P = 0.01) and CFU CAC NOi (-33.84%, P = 0.03). Neither NOi nor the number of CD34(+) cells, which are hematopoietic and endothelial progenitors, changed with rPA. We found no significant differences in NO-related gene expression or oxidative stress-related gene expression with rPA in either CAC type. Therefore, we conclude that although various CAC populations have been related to vascular health, regular physical activity is necessary to maintain CAC NOi and the vulnerability of CACs to short-term reductions in physical activity is population specific.

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

“…It is currently unknown if short-term exercise training results in positive endothelial and CAC responses. Significant reductions in CAC number have been observed in our lab with just 10 days of exercise cessation in older athletes (Witkowski et al 2010) and significant reductions in colony-forming unit (CFU) CAC number and intracellular NO have been observed within the same timeframe in younger adults (Guhanarayan et al 2014). We hypothesized that 10 days of endurance exercise training would improve flow-mediated dilation (FMD) and increase CAC number and redox balance in CD34+ CACs of older, previously sedentary adults.…”

“…Indeed, Guhanarayan et al (2014) found that 10 days of reduced physical activity is sufficient to decrease CFU number and CFU intracellular NO, but this was not evident in the freshly isolated CD34+ CACs. This suggests that there is a cell-type specific response and that some CACs could adapt or respond more quickly to changes in their intracellular environment.…”

Effects of resistance exercise on endothelial progenitor cell mobilization in women

“…Likewise, aerobic exercise training also improves the number of resting circulating EPCs in healthy subjects and patients with cardiovascular disease 1 , 8 . Further, reductions in physical activity reduce the number of select angiogenic cell populations 12 , demonstrating that characteristics of physical activity are important for the liberation of these cells into circulation.…”

Exercise and Stem Cells

“…43 In younger active men, 10 days of reduced physical activity resulted in diminished CAC colony-forming capacity and CAC NOi. 90 Overall, these studies demonstrate flexibility of CACs, along with increased quantity with repeated bouts of activity in both healthy and diseased populations and reversal with detraining.…”