Endurance training increases the number of endothelial progenitor cells in patients with cardiovascular risk and coronary artery disease

Exercise Training Enhances Brachial Artery Endothelial Function, Possibly via Improved HDL-C, not LDL-C and TG, in Patients with Coronary Artery Disease: A Systematic Review and Meta-analysis

BACKGROUND

It remains controversial whether exercise training (EX) improves vascular endothelial function (VEF) independent of lipoprotein changes even though these are therapeutic goals for coronary artery disease (CAD).

OBJECTIVE

The purpose of this study was to systematically review the effects of EX on VEF and blood lipid variables in patients with CAD.

METHODS

This study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched five electronic databases (CINAHL, Embase, PubMed, SportDiscus, and Web of Science) until March 2024 for studies that met the following criteria: (i) patients with CAD aged ≥ 18 years; (ii) structured EX for ≥ 1 week in randomized or nonrandomized controlled studies; and (iii) measured brachial artery flow-mediated dilation (FMD) with or without blood lipid variables. We calculated effect sizes (ESs) and 95% confidence intervals (CIs) using a random-effects model and conducted subgroup analyses to identify the effect of training factors (duration, intensity, and weekly volume) on outcomes.

RESULTS

In total, 11 studies with 19 trials (629 patients, 60 ± 9 years) met the inclusion criteria. We conducted a separate meta-analysis for each of the four outcome measures: FMD (13 ESs), high-density lipoprotein-cholesterol (HDL-C; eight ESs), low-density lipoprotein cholesterol (LDL-C; eight ESs), and triglycerides (TGs; eight ESs). EX significantly increased FMD (mean ES 0.57; 95% CI 0.44-0.70; P < 0.001) and HDL-C levels (mean ES 0.25; 95% CI 0.12-0.39; P < 0.001) but had no effect on LDL-C and TG. Subgroup analyses for FMD found no significant variation in effect by training factor (duration, intensity, and weekly volume).

CONCLUSION

EX improves VEF with increased HDL-C, but we found no changes in LDL-C and TG in patients with CAD, suggesting that HDL-C is preferentially associated with exercise-induced VEF improvement.

Exercise Training After Myocardial Infarction Enhances Endothelial Progenitor Cells Function via NRG-1 Signaling

Vascular regeneration after myocardial infarction (MI) is essential to improve myocardial ischemia, delay post-infarction ventricular remodeling, and improve the long-term prognosis of MI. Endothelial progenitor cells (EPCs) play important roles in the functional repair and homeostatic maintenance of the vascular endothelium. Exercise training stimulates EPC mobilization and increases the number of circulating EPCs, which has beneficial effects on the restoration of vascular integrity and hemodynamic reconstitution. After post-MI exercise training, cardiac function, the myocardial infarct area, and capillary density in the peri-infarct zone were measured. Bone marrow-derived EPCs were isolated from mice to measure the proliferation, migration, and in vitro angiogenesis of EPCs after myocardial infarction exercise. The expression of NRG-1/ErbB4 signaling factor and related proteins in downstream PI3K/AKT signaling pathway were detected, and the level of autocrine NRG-1 in EPCs was detected. Post-MI resistance training, aerobic exercise training, and combined exercise training increased EPC mobilization and proliferation, migration, and tube-forming capacity, promoted myocardial vascular regeneration, improved cardiac function, and reduced infarct size. Exercise training upregulated NRG-1 expression in EPCs, and NRG-1/ErbB4 signaling activated the downstream PI3K/Akt signaling pathway. Moreover, EPCs may have a positive feedback autocrine loop with NRG-1 to improve the function of EPCs and promote vascular repair and regeneration in mice with MI. Exercise training after MI promotes the function of bone marrow-derived EPCs through NRG-1/ErbB4/PI3K/AKT signaling, thus exerting a role in angiogenesis.

Effect of high-intensity intermittent rehabilitation training on physical function, gut microbiome and metabolite after percutaneous coronary intervention in patients with coronary heart disease

Background

Postoperative rehabilitation exercise training after percutaneous coronary intervention (PCI) is crucial for coronary heart disease (CHD) patients in restoring health and preventing recurrence, including high-intensity interval training (HIIT). However, the impact of HIIT on cardiopulmonary function, gut microbiome and metabolite remains underexplored.

Methods

This study included 60 patients with CHD who underwent percutaneous coronary intervention (PCI). Participants were divided into two groups: 33 in the moderate-intensity continuous training (MCT) group and 27 in the high-intensity interval training (HIIT) group. We assessed difference between two training in cardiopulmonary function, 6-minute walk test (6MWT) performance, biochemical indicators, plasma metabolites, and gut microbiome feature at baseline and after 3 months training. Furthermore, we analyzed 6MWT association to gut microbiome and metabolites with group differences.

Results

The 6MWT showed significantly greater improvement in the HIIT group compared to the MCT group (P = 0.0024). Both groups showed reductions in low-density lipoprotein (LDL) levels and increases in peak oxygen uptake (VO2 peak) after training, but the HIIT group demonstrated a larger effect size in these measures. Moreover, subgroup analysis revealed that patients with a history of myocardial infarction (MI) in the HIIT group experienced a more substantial increase in VO2 peak compared to the MCT group (P = 0.04). In addition, we identified 29 gut microbial species and 30 plasma metabolites that were differentially enriched between the two groups, with some showing a significant impact on 6MWT performance.

Conclusions

High-intensity interval training significantly improves 6MWT performance and exercise tolerance in cardiac rehabilitation patients, particularly enhancing VO2 peak in those with a history of MI. HIIT also appears to modulate the gut microbiome, increasing the abundance of Clostridiales and decreasing traumatic acid content, which may contribute to the observed improvements in exercise tolerance.

The effects of exercise training on circulating adhesion molecules in adults: A systematic review and meta-analysis

INTRODUCTION

The current meta-analysis investigated the effects of exercise training on circulating adhesion molecules i.e. soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in adults.

METHOD

PubMed, Web of Science, Scopus and Embase were searched to identify original articles, published in English languages journal from inception up to 31 August 2023 that compared the effects of exercise training with non-exercising control on sICAM-1 and sVCAM-1 in adults. Standardized mean differences (SMDs) and 95% CIs were calculated using random-effect models.

RESULTS

Twenty-three studies including 31 intervention arms and involving 1437 subjects were included in the meta-analysis. Exercise training effectively reduced sICAM-1 [SMD: -0.33 (95% CI -0.56 to -0.11), p = 0.004; I2 = 56.38%, p = 0.001; 23 intervention arms]. Subgroup analyses showed that sICAM-1 decreased in adults with age <60 years (p = 0.01) and BMI ≥ 27 kg/m2 (p = 0.002) and those with metabolic disorders (p = 0.004) and cardiovascular diseases (p = 0.005). In addition, aerobic (p = 0.02) and resistance training (p = 0.007) are effective in reducing sICAM-1. However, exercise training did not indicate a superior effect on sVCAM-1 [SMD: -0.12 (95% CI -0.29 to 0.05), p = 0.17; I2 = 36.29%, p = 0.04; 23 intervention arms].

CONCLUSION

Our results show that exercise training reduces sICAM-1, but not for sVCAM-1, where both aerobic and resistance training is effective in reducing sICAM-1 in adults with metabolic disorders and cardiovascular diseases.

TRIAL REGISTRATION

The current meta-analysis was registered at www.crd.york.ac.uk/prospero with ID registration number: CRD42023410474.

Micro- and Macrovascular Effects of Inflammation in Peripheral Artery Disease-Pathophysiology and Translational Therapeutic Approaches

Inflammation has a critical role in the development and progression of atherosclerosis. On the molecular level, inflammatory pathways negatively impact endothelial barrier properties and thus, tissue homeostasis. Conformational changes and destruction of the glycocalyx further promote pro-inflammatory pathways also contributing to pro-coagulability and a prothrombotic state. In addition, changes in the extracellular matrix composition lead to (peri-)vascular remodelling and alterations of the vessel wall, e.g., aneurysm formation. Moreover, progressive fibrosis leads to reduced tissue perfusion due to loss of functional capillaries. The present review aims at discussing the molecular and clinical effects of inflammatory processes on the micro- and macrovasculature with a focus on peripheral artery disease.

Exercise protects vascular function by countering senescent cells in older adults

Blood vessels are key conduits for the transport of blood and circulating factors. Abnormalities in blood vessels promote cardiovascular disease (CVD), which has become the most common disease as human lifespans extend. Aging itself is not pathogenic; however, the decline of physiological and biological function owing to aging has been linked to CVD. Although aging is a complex phenomenon that has not been comprehensively investigated, there is accumulating evidence that cellular senescence aggravates various pathological changes associated with aging. Emerging evidence shows that approaches that suppress or eliminate cellular senescence preserve vascular function in aging-related CVD. However, most pharmacological therapies for treating age-related CVD are inefficient. Therefore, effective approaches to treat CVD are urgently required. The benefits of exercise for the cardiovascular system have been well documented in basic research and clinical studies; however, the mechanisms and optimal frequency of exercise for promoting cardiovascular health remain unknown. Accordingly, in this review, we have discussed the changes in senescent endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) that occur in the progress of CVD and the roles of physical activity in CVD prevention and treatment.

Aerobically trained older adults show impaired resting, but preserved exercise-induced circulating progenitor cell count, which was not improved by sprint interval training

Older adults exhibit a reduced number and function of CD34 + circulating progenitor cells (CPC), a known risk factor for cardiovascular disease. Exercise promotes the mobilisation of CPCs from bone marrow, so whether ageing per se or physical inactivity in older age reduces CPCs is unknown. Thus, this study examined the effect of age on resting and exercise-induced changes in CPCs in aerobically trained adults and the effect of 8 weeks of sprint interval training (SIT) on resting and exercise-induced CPCs in older adults. Twelve young (22-34 years) and nine older (63-70 years) adults participated in the study. Blood was sampled pre and immediately post a graded exercise test to exhaustion in both groups. Older participants repeated the process after 8 weeks of SIT (3 × 20 s 'all-out' sprints, 2 × a week). Total CPCs (CD34⁺) and endothelial progenitor cells (EPCs: CD34⁺KDR⁺) were determined by flow cytometry. Older adults exhibited lower basal total CD34⁺ CPCs (828 ± 314 vs. 1186 ± 272 cells·mL^-1, p = 0.0149) and CD34⁺KDR⁺ EPCs (177 ± 128 vs. 335 ± 92 cells·mL^-1, p = 0.007) than younger adults. The maximal exercise test increased CPCs in young (CD34⁺: p = 0.004; CD34⁺KDR⁺: p = 0.017) and older adults (CD34⁺: p < 0.001; CD34⁺KDR⁺: p = 0.008), without difference between groups (p = 0.211). SIT did not alter resting or exercise-induced changes in CPCs in the older cohort (p > 0.232). This study suggests age per se does not impair exercise-induced CPC counts, but does lower resting CPC counts.

The Long Telling Story of "Endothelial Progenitor Cells": Where Are We at Now?

Endothelial progenitor cells (EPCs): The name embodies years of research and clinical expectations, but where are we now? Do these cells really represent the El Dorado of regenerative medicine? Here, past and recent literature about this eclectic, still unknown and therefore fascinating cell population will be discussed. This review will take the reader through a temporal journey that, from the first discovery, will pass through years of research devoted to attempts at their definition and understanding their biology in health and disease, ending with the most recent evidence about their pathobiological role in cardiovascular disease and their recent applications in regenerative medicine.

Endothelial progenitor cell mobilization based on exercise volume in patients with cardiovascular disease and healthy individuals: a systematic review and meta-analysis

Endothelial progenitor cells (EPCs) play a vital role in protecting endothelial dysfunction and cardiovascular disease (CVD). Physical exercise stimulates the mobilization of EPCs, and along with vascular endothelial growth factor (VEGF), promotes EPC differentiation, and contributes to vasculogenesis. The present meta-analysis examines the exercise-induced EPC mobilization and has an impact on VEGF in patients with CVD and healthy individuals. Database research was conducted (PubMed, EMBASE, Cochrane Library of Controlled Trials) by using an appropriate algorithm to indicate the exercise-induced EPC mobilization studies. Eligibility criteria included EPC measurements following exercise in patients with CVD and healthy individuals. A continuous random effect model meta-analysis (PROSPERO-CRD42019128122) was used to calculate mean differences in EPCs (between baseline and post-exercise values or between an experimental and control group). A total of 1460 participants (36 studies) were identified. Data are presented as standard mean difference (Std.MD) and 95% confidence interval (95% CI). Aerobic training stimulates the mobilization of EPCs and increases VEGF in patients with CVD (EPCs: Std.MD: 1.23, 95% CI: 0.70-1.76; VEGF: Std.MD: 0.76, 95% CI:0.16-1.35) and healthy individuals (EPCs: Std.MD: 1.11, 95% CI:0.53-1.69; VEGF: Std.MD: 0.75, 95% CI: 0.01-1.48). Acute aerobic exercise (Std.MD: 1.40, 95% CI: 1.00-1.80) and resistance exercise (Std.MD: 0.46, 95%CI: 0.10-0.82) enhance EPC numbers in healthy individuals. Combined aerobic and resistance training increases EPC mobilization (Std.MD:1.84, 95% CI: 1.03-2.64) in patients with CVD. Adequate exercise volume (>60%VO2max >30 min; P = 0.00001) yields desirable results. Our meta-analysis supports the findings of the literature. Exercise volume is required to obtain clinically significant results. Continuous exercise training of high-to-moderate intensity with adequate duration as well as combined training with aerobic and resistance exercise stimulates EPC mobilization and increases VEGF in patients with CVD and healthy individuals.

Efficacy of interval exercise training to improve vascular health in sedentary postmenopausal females

BACKGROUND

Menopause represents a turning point where vascular damage begins to outweigh reparative processes, leading to increased cardiovascular disease (CVD) risk. Exercise training reduces CVD risk in postmenopausal females via improvements in traditional risk factors and direct changes to the vasculature. We assessed the effect of moderate (MODERATE-IT) versus heavy (HEAVY-IT) intensity interval exercise training upon markers of cardiovascular health and vascular repair in postmenopausal females.

METHODS

Twenty-seven healthy postmenopausal females (56 ± 4 yr) were assigned to 12 weeks of either MODERATE-IT or HEAVY-IT, twice per week. MODERATE-IT consisted of 10s work, and 10s active recovery repeated for 30 min. HEAVY-IT comprised 30s work, and 30s active recovery repeated for 21 ± 2 min. Endothelial function (flow-mediated dilation), arterial stiffness (pulse wave velocity), and V̇O_2peak were assessed pre-training and post-training. Blood samples were obtained pre-training and post-training for enumeration of circulating angiogenic cells (CACs), culture of CACs, and lipoprotein profile.

RESULTS

V̇O_2peak increased 2.4 ± 2.8 ml/kg/min following HEAVY-IT only (p < 0.05). Brachial blood pressure and endothelial function were unchanged with exercise training (p > 0.05). Peripheral pulse wave velocity reduced 8% with exercise training, irrespective of intensity (p < 0.05). Exercise training had no effect on lipoprotein profile or endothelin-1 (p > 0.05). CAC adhesion to vascular smooth muscle cells (VSMC) increased 30 min post plating following MODERATE-IT only (p < 0.05).

CONCLUSIONS

HEAVY-IT was more effective at increasing V̇O_2peak in postmenopausal females. The ability of CACs to adhere to VSMC improved following MODERATE-IT but not HEAVY-IT. Interval training had the same effect on endothelial function (no change) and arterial stiffness (reduced), regardless of exercise intensity.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

The impact of different forms of exercise on circulating endothelial progenitor cells in cardiovascular and metabolic disease

Circulating endothelial progenitor cells (EPCs) contribute to vascular repair and their monitoring could have prognostic clinical value. Exercise is often prescribed for the management of cardiometabolic diseases, however, it is not fully understood how it regulates EPCs.

OBJECTIVES

to systematically examine the acute and chronic effects of different exercise modalities on circulating EPCs in patients with cardiovascular and metabolic disease.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

six electronic databases and reference lists of eligible studies were searched to April 2021. Thirty-six trials met the inclusion criteria including 1731 participants. Acute trials: in chronic heart failure (CHF), EPC mobilisation was acutely increased after high intensity interval or moderate intensity continuous exercise training, while findings were inconclusive after a cardiopulmonary cycling exercise test. Maximal exercise tests acutely increased EPCs in ischaemic or revascularized coronary artery disease (CAD) patients. In peripheral arterial disease (PAD), EPC levels increased up to 24 h post-exercise. In patients with compromised metabolic health, EPC mobilisation was blunted after a single exercise session. Chronic trials: in CHF and acute coronary syndrome, moderate intensity continuous protocols, with or without resistance exercise or calisthenics, increased EPCs irrespective of EPC identification phenotype. Findings were equivocal in CAD regardless of exercise mode, while in severe PAD disease EPCs increased. High intensity interval training increased EPCs in hypertensive metabolic syndrome and heart failure reduced ejection fraction.

CONCLUSION

the clinical condition and exercise modality influence the degree of EPC mobilisation and magnitude of EPC increases in the long term.

Physical Exercise Protects Against Endothelial Dysfunction in Cardiovascular and Metabolic Diseases

Increasing evidence shows that endothelial cells play critical roles in maintaining vascular homeostasis, regulating vascular tone, inhibiting inflammatory response, suppressing lipid leakage, and preventing thrombosis. The damage or injury of endothelial cells induced by physical, chemical, and biological risk factors is a leading contributor to the development of mortal cardiovascular and cerebrovascular diseases. However, the underlying mechanism of endothelial injury remains to be elucidated. Notably, no drugs effectively targeting and mending injured vascular endothelial cells have been approved for clinical practice. There is an urgent need to understand pathways important for repairing injured vasculature that can be targeted with novel therapies. Exercise training-induced protection to endothelial injury has been well documented in clinical trials, and the underlying mechanism has been explored in animal models. This review mainly summarizes the protective effects of exercise on vascular endothelium and the recently identified potential therapeutic targets for endothelial dysfunction.

CD34+ progenitors are predictive of mortality and are associated with physical activity in cardiovascular disease patients

BACKGROUND AND AIMS

Circulating progenitor cells (CPCs) play an important role in vascular repair and can influence cardiovascular (CV) health and longevity. Exercise is known to modulate these cells via mobilization from the bone marrow. The primary aims of this study were to evaluate the association of CPCs with mortality and explore the association between physical activity (PA) and CPCs.

METHODS

1751 individuals from the Framingham Offspring cohort (66 ± 9 years [40-92 years], 54% female) were included in the study. CPCs (CD34^+, CD34⁺CD133⁺, CD34⁺CD133⁺KDR⁺) were measured by flow cytometry. Multivariable Cox regression analyses were performed to investigate relationship of CPCs with future CV event and mortality. Multivariate regression analyses were performed to determine the relationship between self-reported PA and CPC counts.

RESULTS

Following adjustment for standard risk factors, there was an inverse association between CD34⁺ CPCs and all-cause mortality (hazard ratio (HR) per unit increase in CD34⁺, 0.79; 95% CI 0.64-0.98, p = 0.036). CD34⁺CD133⁺ CPCs were inversely associated with CV mortality (HR 0.63, 95% CI 0.44-0.91, p = 0.013). Associations of CD34⁺ and CD34⁺CD133⁺ with mortality were strongest in participants with pre-existing CVD. PA was associated with CD34⁺ CPCs only in CVD participants (PA Index: β = 0.176, p = 0.003; moderate-to-vigorous [MVPA]: β = 0.159, p = 0.007). This relationship was maintained after adjustment for confounding variables.

CONCLUSIONS

A higher number of CD34⁺ and CD34⁺ CD133⁺ CPCs was inversely associated with all-cause and CV mortality. These associations were strongest in participants with CVD. PA is independently associated with CD34⁺ CPCs in individuals with CVD only, suggestive of greater benefit for this population group.

Coronary Artery Disease and Endothelial Dysfunction: Novel Diagnostic and Therapeutic Approaches

Coronary artery disease is the leading cause of morbidity and mortality worldwide. The most common pathophysiologic substrate is atherosclerosis which is an inflammatory procedure that starts at childhood and develops throughout life. Endothelial dysfunction is associated with the initiation and progression of atherosclerosis and is characterized by the impaired production of nitric oxide. In general, endothelial dysfunction is linked to poor cardiovascular prognosis and different methods, both invasive and non-invasive, have been developed for its evaluation. Ultrasound evaluation of flow mediated dilatation of the branchial artery is the most commonly used method to assessed endothelial function while intracoronary administration of vasoactive agents may be also be used to test directly endothelial properties of the coronary vasculature. Endothelial dysfunction has also been the subject of therapeutic interventions. This review article summarizes the knowledge about evaluation of endothelial function in acute coronary syndromes and stable coronary artery disease and demonstrates the current therapeutic approaches against endothelial dysfunction.

Adult Stem Cells: Beyond Regenerative Tool, More as a Bio-Marker in Obesity and Diabetes

Obesity, diabetes, and cardiovascular diseases are increasing rapidly worldwide and it is therefore important to know the effect of exercise and medications for diabetes and obesity on adult stem cells. Adult stem cells play a major role in remodeling and tissue regeneration. In this review we will focus mainly on two adult stem/progenitor cells such as endothelial progenitor cells and mesenchymal stromal cells in relation to aerobic exercise and diabetes medications, both of which can alter the course of regeneration and tissue remodelling. These two adult precursor and stem cells are easily obtained from peripheral blood or adipose tissue depots, as the case may be and are precursors to endothelium and mesenchymal tissue (fat, bone, muscle, and cartilage). They both are key players in maintenance of cardiovascular and metabolic homeostasis and can act also as useful biomarkers.

Exercise and Cardiovascular Progenitor Cells

Autologous stem/progenitor cell-based methods to restore blood flow and function to ischemic tissues are clinically appealing for the substantial proportion of the population with cardiovascular diseases. Early preclinical and case studies established the therapeutic potential of autologous cell therapies for neovascularization in ischemic tissues. However, trials over the past ∼15 years reveal the benefits of such therapies to be much smaller than originally estimated and a definitive clinical benefit is yet to be established. Recently, there has been an emphasis on improving the number and function of cells [herein generally referred to as circulating angiogenic cells (CACs)] used for autologous cell therapies. CACs include of several subsets of circulating cells, including endothelial progenitor cells, with proangiogenic potential that is largely exerted through paracrine functions. As exercise is known to improve CV outcomes such as angiogenesis and endothelial function, much attention is being given to exercise to improve the number and function of CACs. Accordingly, there is a growing body of evidence that acute, short-term, and chronic exercise have beneficial effects on the number and function of different subsets of CACs. In particular, recent studies show that aerobic exercise training can increase the number of CACs in circulation and enhance the function of isolated CACs as assessed in ex vivo assays. This review summarizes the roles of different subsets of CACs and the effects of acute and chronic exercise on CAC number and function, with a focus on the number and paracrine function of circulating CD34+ cells, CD31+ cells, and CD62E+ cells. © 2019 American Physiological Society. Compr Physiol 9:767-797, 2019.

Effects of Catheterization on Artery Function and Health: When Should Patients Start Exercising Following Their Coronary Intervention?

Coronary artery disease (CAD) is a leading cause of death worldwide, and percutaneous transluminal coronary angiography (PTCA) and/or percutaneous coronary intervention (PCI; angioplasty) are commonly used to diagnose and/or treat the obstructed coronaries. Exercise-based rehabilitation is recommended for all CAD patients; however, most guidelines do not specify when exercise training should commence following PTCA and/or PCI. Catheterization can result in arterial dysfunction and acute injury, and given the fact that exercise, particularly at higher intensities, is associated with elevated inflammatory and oxidative stress, endothelial dysfunction and a pro-thrombotic milieu, performing exercise post-PTCA/PCI may transiently elevate the risk of cardiac events. This review aims to summarize extant literature relating to the impacts of coronary interventions on arterial function, including the time-course of recovery and the potential deleterious and/or beneficial impacts of acute versus long-term exercise. The current literature suggests that arterial dysfunction induced by catheterization recovers 4-12 weeks following catheterization. This review proposes that a period of relative arterial vulnerability may exist and exercise during this period may contribute to elevated event susceptibility. We therefore suggest that CAD patients start an exercise training programme between 2 and 4 weeks post-PCI, recognizing that the literature suggest there is a 'grey area' for functional recovery between 2 and 12 weeks post-catheterization. The timing of exercise onset should take into consideration the individual characteristics of patients (age, severity of disease, comorbidities) and the intensity, frequency and duration of the exercise prescription.

Potential Cellular and Biochemical Mechanisms of Exercise and Physical Activity on the Ageing Process

Exercise in young adults has been consistently shown to improve various aspects of physiological and psychological health but we are now realising the potential benefits of exercise with advancing age. Specifically, exercise improves cardiovascular, musculoskeletal, and metabolic health through reductions in oxidative stress, chronic low-grade inflammation and modulating cellular processes within a variety of tissues. In this this chapter we will discuss the effects of acute and chronic exercise on these processes and conditions in an ageing population, and how physical activity affects our vasculature, skeletal muscle function, our immune system, and cardiometabolic risk in older adults.

Endothelial Regenerative Capacity and Aging: Influence of Diet, Exercise and Obesity

Background:

The endothelium plays an important role in cardiovascular regulation, from blood flow to platelet aggregation, immune cell infiltration and demargination. A dysfunctional endo-thelium leads to the onset and progression of Cardiovascular Disease (CVD). The aging endothelium displays significant alterations in function, such as reduced vasomotor functions and reduced angio-genic capabilities. This could be partly due to elevated levels of oxidative stress and reduced endothe-lial cell turnover. Circulating angiogenic cells, such as Endothelial Progenitor Cells (EPCs) play a significant role in maintaining endothelial health and function, by supporting endothelial cell prolifera-tion, or via incorporation into the vasculature and differentiation into mature endothelial cells. Howev-er, these cells are reduced in number and function with age, which may contribute to the elevated CVD risk in this population. However, lifestyle factors, such as exercise, physical activity obesity, and dietary intake of omega-3 polyunsaturated fatty acids, nitrates, and antioxidants, significantly af-fect the number and function of these circulating angiogenic cells.

Conclusion:

This review will discuss the effects of advancing age on endothelial health and vascular regenerative capacity, as well as the influence of diet, exercise, and obesity on these cells, the mecha-nistic links and the subsequent impact on cardiovascular health

Myocardial Ischemia and Mobilization of Circulating Progenitor Cells

Background

The response of progenitor cells (PCs) to transient myocardial ischemia in patients with coronary artery disease remains unknown. We aimed to investigate the PC response to exercise‐induced myocardial ischemia (ExMI) and compare it to flow mismatch during pharmacological stress testing.

Methods and Results

A total of 356 patients with stable coronary artery disease underwent 99mTc‐sestamibi myocardial perfusion imaging during exercise (69%) or pharmacological stress (31%). CD34⁺ and CD34⁺/chemokine (C‐X‐C motif) receptor 4 PCs were enumerated by flow cytometry. Change in PC count was compared between patients with and without myocardial ischemia using linear regression models. Vascular endothelial growth factor and stromal‐derived factor‐1α were quantified. Mean age was 63±9 years; 76% were men. The incidence of ExMI was 31% and 41% during exercise and pharmacological stress testing, respectively. Patients with ExMI had a significant decrease in CD34⁺/chemokine (C‐X‐C motif) receptor 4 (−18%, P=0.01) after stress that was inversely correlated with the magnitude of ischemia (r=−0.19, P=0.003). In contrast, patients without ExMI had an increase in CD34⁺/chemokine (C‐X‐C motif) receptor 4 (14.7%, P=0.02), and those undergoing pharmacological stress had no change. Plasma vascular endothelial growth factor levels increased (15%, P<0.001) in all patients undergoing exercise stress testing regardless of ischemia. However, the change in stromal‐derived factor‐1α level correlated inversely with the change in PC counts in those with ExMI (P=0.03), suggesting a greater decrease in PCs in those with a greater change in stromal‐derived factor‐1α level with exercise.

Conclusions

ExMI is associated with a significant decrease in circulating levels of CD34⁺/chemokine (C‐X‐C motif) receptor 4 PCs, likely attributable, at least in part, to stromal‐derived factor‐1α–mediated homing of PCs to the ischemic myocardium. The physiologic consequences of this uptake of PCs and their therapeutic implications need further investigation.

Adherence to lifestyle modifications after a cardiac rehabilitation program and endothelial progenitor cells

An increase of endothelial progenitor cells (EPCs) among acute myo-cardial infarction (AMI) patients participating in a cardiac rehabilitation (CR) program has been reported, but no data on the impact of adherence to lifestyle recommendations provided during a CR program on EPCs are available. It was our aim to investigate the effect of adherence to lifestyle recommendations on EPCs, inflammatory and functional parameters after six months of a CR program in AMI patients. In 110 AMI patients (90 male/20 female; mean age 57.9 ± 9.4 years) EPCs, high sensitivity C-reactive protein (hsCRP), N-terminal pro-brain natriuretic peptide (NT-ProBNP) levels, and cardiopulmonary testings were determined at the end of the CR (T1) and at a six-month follow-up (T2). At T2 we administered a questionnaire assessing dietary habits and physical activity. At T2, we observed a decrease of EPCs (p<0.05), of hsCRP (p=0.009) and of NT-ProBNP (p<0.0001). Patient population was divided into three categories by Healthy Lifestyle (HL) score (none/low, moderate and high adherence to lifestyle recommendations). We observed a significant association between adherence to lifestyle recommendations, increase in EPCs and exercise capacity between T1 and T2 (Δ EPCs p for trend <0.05; ΔWatt max p for trend=0.004). In a multivariate logistic regression analyses, being in the highest tertile of HL score affected the likelihood of an increase of EPC levels at T2 [OR (95% confidence interval): 3.36 (1.0–10.72) p=0.04]. In conclusion, adherence to lifestyle recommendations provided during a CR program positively influences EPC levels and exercise capacity.

Effects of pitavastatin on walking capacity and CD34+/133+ cell number in patients with peripheral artery disease

This multi-center prospective non-randomized comparative study investigated the effects of pitavastatin in patients with peripheral artery disease (PAD) in terms of exercise tolerance capacities and peripheral CD34+/133+ cell numbers. At baseline, a peripheral blood test was administered to 75 patients with PAD, along with a treadmill exercise test using the Skinner-Gardner protocol to measure asymptomatic walking distance (AWD) and maximum walking distance (MWD). Each patient was assigned to a 6-month pitavastatin treatment group (n = 53) or a control group (n = 22), according to the patient's preference. The tests were repeated in both groups at 3 and 6 months. Baseline AWD and MWD correlated positively with the ankle-brachial pressure index (r = 0.342, p = 0.0032 and r = 0.324, p = 0.0054, respectively). Both AWD and MWD values improved at 3 and 6 months compared with baseline, and the degrees of their improvement were higher in the pitavastatin treatment group. CD34+/133+ cell numbers did not change over time or between groups. Eighty-seven percent of patients in the treatment group attained low-density lipoprotein cholesterol levels below 100 mg/dL after 3 months. The study shows that pitavastatin may be effective in increasing exercise tolerance capacity in patients with PAD.

Endothelial and cardiac progenitor cells for cardiovascular repair: A controversial paradigm in cell therapy

Stem cells have the potential to differentiate into cardiovascular cell lineages and to stimulate tissue regeneration in a paracrine/autocrine manner; thus, they have been extensively studied as candidate cell sources for cardiovascular regeneration. Several preclinical and clinical studies addressing the therapeutic potential of endothelial progenitor cells (EPCs) and cardiac progenitor cells (CPCs) in cardiovascular diseases have been performed. For instance, autologous EPC transplantation and EPC mobilization through pharmacological agents contributed to vascular repair and neovascularization in different animal models of limb ischemia and myocardial infarction. Also, CPC administration and in situ stimulation of resident CPCs have been shown to improve myocardial survival and function in experimental models of ischemic heart disease. However, clinical studies using EPC- and CPC-based therapeutic approaches have produced mixed results. In this regard, intracoronary, intra-myocardial or intramuscular injection of either bone marrow-derived or peripheral blood progenitor cells has improved pathological features of tissue ischemia in humans, despite modest or no clinical benefit has been observed in most cases. Also, the intriguing scientific background surrounding the potential clinical applications of EPC capture stenting is still waiting for a confirmatory proof. Moreover, clinical findings on the efficacy of CPC-based cell therapy in heart diseases are still very preliminary and based on small-size studies. Despite promising evidence, widespread clinical application of both EPCs and CPCs remains delayed due to several unresolved issues. The present review provides a summary of the different applications of EPCs and CPCs for cardiovascular cell therapy and underlies their advantages and limitations.

Exercise training with dietary restriction enhances circulating irisin level associated with increasing endothelial progenitor cell number in obese adults: an intervention study

Objective

Circulating endothelial progenitor cells (EPCs) correlate negatively with obesity. Previous studies have shown that exercise significantly restores circulating EPC levels in obese people; however, the underlying mechanisms have not been elucidated. Recently, irisin has been reported to have a critical role in the regulation of EPCs. This exercise-induced myokine has been demonstrated to play a therapeutic role in obesity. In this study, we hypothesized that the increase in circulating irisin may form a link with increasing EPC levels in obese people after exercise.

Methods

Seventeen obese adults completed an 8-week program of combined exercise and dietary intervention. Clinical characteristics, blood biochemistry, and circulating irisin levels of subjects were measured before and after eight weeks of training. EPC levels were evaluated via flow cytometry, and EPC migratory and adhesive functions were also determined.

Results

Circulating irisin levels significantly increased following the 8-week training program (P < 0.05). We furthermore observed an improvement in EPC numbers (P < 0.05), and EPC migratory and adhesive functions (P < 0.001 and P < 0.05, respectively) after the intervention. Additionally, we detected a positive correlation between changes in irisin and changes in EPC number (r = 0.52, P < 0.05).

Discussion

For the first time, a positive correlation between increasing irisin levels and increasing EPC levels has been reported after an 8-week program, consisting of exercise and dietary intervention. This result suggests a novel effect of irisin on the regulation of EPC mobilization, which might contribute to improvement of endothelial function in obese people.

Increased Endothelial Progenitor Cell Number in Early Stage of Endometrial Cancer

OBJECTIVES

It is generally believed that circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) reflect the state of the endothelium, its injury and/or repair possibilities. In different types of cancers, increased numbers of CECs and EPCs were found, suggesting their participation in cancer angiogenesis. The objective of this study was to determine whether, in the blood circulation of women with early endometrial cancer, CEC and EPC levels differ from those of healthy women of similar age.

METHODS

For CEC number evaluation, samples of peripheral blood cells of women with endometrial carcinoma and control subjects were labeled with anti-CD31 and anti-CD45 antibodies; for EPCs, with anti-VEGFR2 (vascular-endothelium growth factor receptor 2)/KDR and anti-CD34 antibodies. The CEC and EPC cells were then quantified by flow cytometry.

RESULTS

Endothelial progenitor cell numbers (CD34, VEGFR2/KDR) in the peripheral blood of women with endometrial carcinoma were significantly augmented as compared with those of control healthy women and CEC numbers (CD31, CD45) were similar in both groups. Cancer patients were divided according to the grading into G1 and G2 groups and according to the stage into International Federation of Gynecology and Obstetrics (FIGO) stage IA and FIGO IB groups. Statistically significant augmented EPC numbers were demonstrated only in G1 and FIGO IA patients.

CONCLUSIONS

These results strongly suggest new vessel formation from recruited endothelial precursors as being involved mainly at the early stages of tumor progression.

Effect of exercise training on endothelial function in heart failure patients: A systematic review meta-analysis

OBJECTIVE

Endothelial dysfunction contributes to the development and progression of cardiovascular disease and heart failure (HF) and is associated with an increased risk of mortality. Flow-mediated dilation (FMD) is widely utilised to assess endothelial function and is improved with exercise training in heart failure patients. The aim of this meta-analysis is to quantify the effect of exercise training in patients with heart failure.

BACKGROUND

A large number of studies now exist that have examined endothelial function in patients with heart failure. We sought to add to the current literature by quantifying the effect of exercise training on endothelial function.

METHODS

We conducted database searches (PubMed, EMBASE, PROQUEST and Cochrane Trials Register to June 2016) for exercise based rehabilitation trials in heart failure, using search terms exercise training, endothelial function, flow-mediated dilation (FMD) and endothelial progenitor cells (EPCs).

RESULTS

The 16 included studies provided a total of 529 participants, 293 in an intervention and 236 in controls groups. FMD was improved with exercise training in exercise vs. control, SMD of 1.08 (95%CI 0.70 to 1.46, p<0.00001).

CONCLUSION

Overall exercise training improved endothelial function, assessed via FMD, and endothelial progenitor cells in heart failure patients.

Circulating progenitor cells and coronary microvascular dysfunction: Results from the NHLBI-sponsored Women's Ischemia Syndrome Evaluation - Coronary Vascular Dysfunction Study (WISE-CVD)

BACKGROUND AND AIMS

Ischemia stimulates a reparative response resulting in mobilization of circulating progenitor cells (CPCs). We hypothesized that women with chronic myocardial ischemia from coronary microvascular disease (CMD) will mobilize CPCs.

METHODS

In 123 women with ischemic symptoms and signs but no obstructive coronary artery disease (CAD) enrolled in the Women's Ischemia Syndrome Evaluation - Coronary Vascular Dysfunction Study (WISE-CVD), we measured coronary flow reserve (CFR) in response to intracoronary adenosine. Peripheral blood CPCs were measured using flow cytometry for expression of CD34, CD133, CXCR4, and VEGFR2.

RESULTS

Subjects were 53 ± 11 years, BMI 30 ± 8; 44% hypertensive, 11% diabetic, 23% hyperlipidemic and 7% smokers. Lower CFR correlated inversely with higher levels of hematopoietic-enriched CD34+ (r = -0.23, p = 0.011), CD34+/CD133+ (r = -0.24, p = 0.008), and CD34+/CXCR4+ (r = -0.19, p = 0.036) cells. In multivariable regression analyses, after adjusting for traditional cardiovascular risk factors, lower CFR remained significantly associated with elevated levels of CD34+ (β -0.18, p = 0.042), CD34+/CD133+ (β -0.24, p = 0.036), and CD34+/CXCR4+ (β -0.22, p = 0.050) cells. We found no association between CFR and CD34+/VEGFR2+ cells.

CONCLUSIONS

In women with non-obstructive CAD, impaired CFR is associated with higher levels of CPCs, suggesting that chronic myocardial ischemia from CMD stimulates CPC mobilization. The functional significance of elevated CPCs in these subjects requires further investigation as a potential biomarker and treatment target.

The Beneficial Effects of Cardiac Rehabilitation on the Function and Levels of Endothelial Progenitor Cells

Cardiac rehabilitation (CR) is a comprehensive program, which mainly focusses on exercise training, disease evaluation, cardiovascular risk factors control, medication therapy, psychosocial intervention, and patient education. Although the beneficial properties of CR have been widely evidenced, its mechanism is still not completely clarified. To date, endothelial progenitor cells (EPCs) have been explored by emerging studies, and evidence has suggested that CR, especially exercise training, significantly increases the function and levels of EPCs, which is likely to elucidate the profiting mechanism of CR. Thus, this review summarises the potential relationship between CR and EPCs with an aim of providing novel directions for future CR research.

Association of CD34/CD133/VEGFR2-Positive Cell Numbers with Eicosapentaenoic Acid and Postprandial Hyperglycemia in Patients with Coronary Artery Disease

OBJECTIVES

Circulating endothelial progenitor cells (EPCs), which have the ability to differentiate into mature endothelial cells, can elicit angiogenesis, vasculogenesis and vessel repair in cardiac ischemia and vascular injuries caused by endothelial damage. Serum 1,5-anhydro-d-glucitol (1,5-AG), which is a useful clinical marker of postprandial hyperglycemia, eicosapentaenoic acid (EPA), and arachidonic acid (AA) are newly identified risk factors for coronary artery disease (CAD). However, no previous study has reported the associations between EPCs and 1,5-AG, EPA, and AA levels in CAD patients with type 2 diabetes mellitus (DM).

METHODS

Peripheral EPCs, assessed as CD34+ cells co-expressing CD133 and vascular endothelial growth factor receptor-2, were studied in 76 CAD patients (mean age, 69.2±11.3years) with DM. Serum 1,5-AG, EPA, and AA levels were measured.

RESULTS

EPC numbers showed a significant association with 1,5-AG and HbA1c (r=0.290; p=0.037 and r=-0.328; p=0.011, respectively). In addition, there were significant associations between EPC numbers and EPA and body mass index (BMI) (r=0.354; p=0.027 and r=-0.402; p=0.002, respectively). In multiple linear regression analysis, HbA1c, BMI, and EPA values had significant associations with EPC numbers (β=-0.316, 95% confidence interval (CI) -0.256 to -0.008, p=0.037; β=-0.413, 95% CI -0.099 to -0.017, p=0.007; and β=0.400, 95% CI 0.004 to 0.002, p=0.010, respectively).

CONCLUSIONS

EPC number is associated with HbA1c, 1,5-AG, EPA, and BMI values, suggesting that postprandial hyperglycemia and n-3 polyunsaturated fatty acids contribute to EPC recruitment in CAD patients with type 2 DM.

Intradialytic aerobic cycling exercise alleviates inflammation and improves endothelial progenitor cell count and bone density in hemodialysis patients

Inflammation, endothelial dysfunction, and mineral bone disease are critical factors contributing to morbidity and mortality in hemodialysis (HD) patients. Physical exercise alleviates inflammation and increases bone density. Here, we investigated the effects of intradialytic aerobic cycling exercise on HD patients. Forty end-stage renal disease patients undergoing HD were randomly assigned to either an exercise or control group. The patients in the exercise group performed a cycling program consisting of a 5-minute warm-up, 20 minutes of cycling at the desired workload, and a 5-minute cool down during 3 HD sessions per week for 3 months. Biochemical markers, inflammatory cytokines, nutritional status, the serum endothelial progenitor cell (EPC) count, bone mineral density, and functional capacity were analyzed. After 3 months of exercise, the patients in the exercise group showed significant improvements in serum albumin levels, the body mass index, inflammatory cytokine levels, and the number of cells positive for CD133, CD34, and kinase insert domain-conjugating receptor. Compared with the exercise group, the patients in the control group showed a loss of bone density at the femoral neck and no increases in EPCs. The patients in the exercise group also had a significantly greater 6-minute walk distance after completing the exercise program. Furthermore, the number of EPCs significantly correlated with the 6-minute walk distance both before and after the 3-month program. Intradialytic aerobic cycling exercise programs can effectively alleviate inflammation and improve nutrition, bone mineral density, and exercise tolerance in HD patients.

Associations among cardiorespiratory endurance, body mass index and blood pressure in Han Chinese children: results from the 2010 Chinese National Survey On Students' Constitution and Health

The associations among cardiorespiratory endurance (CRE), body mass index (BMI) and blood pressure (BP) in children are still unclear. This study aimed to examine the relationships among CRE, BMI and BP in Chinese children. Data were derived from the 2010 Chinese National Survey on Students' Constitution and Health. An endurance run test was used to determine CRE and children were stratified into low and high/moderate CRE groups. BMI was dichotomized into non-overweight and overweight. Among overweight children aged 7-12 years, the risk of high BP (HBP) was significantly higher in the low CRE group than in the high/moderate CRE group (in boys, odds ratio=1.13, 95% confidence interval: 1.03-1.24, P=0.010; in girls, odds ratio=1.18, 95% confidence interval: 1.04-1.33, P=0.010) after adjusting for age, BMI, socioeconomic status and area of residence. However, among all children aged 13-18 years and non-overweight children aged 7-12 years, we did not observe similar results. Higher CRE is associated with lower BP. Overweight children have a significantly higher risk of HBP and low CRE may increase the risk of HBP, independently of BMI, among 7- to 12-year-old overweight children.

Prognostic relevance of circulating endothelial progenitor cells in patients with chronic heart failure

Novel strategies for a tailored risk prediction in chronic heart failure (CHF) are crucial to identify patients at very high risk for an improved patient management and to specify treatment regimens. Endothelial progenitor cells (EPCs) are an important endogenous repair mechanism with the ability to counteract endothelial injury and the possibility of new vessel formation. We hypothesised that exhaustion of circulating EPCs may be a suitable prognostic biomarker in patients with CHF. EPCs, defined as CD34+CD45dimKDR+ cells, were analysed using fluorescence-activated cell sorting. EPCs were measured in 185 patients with CHF including 87 (47 %) patients with ischaemic aetiology and 98 (53 %) patients with non-ischaemic CHF and followed for a median time of 2.7 years. During this period, 34.7 % of patients experienced the primary study endpoint all-cause mortality. EPC count was a significant and independent inverse predictor of mortality with an hazard ratio hazard ratio (HR) per increase of one standard deviation (1-SD) of 0.47 (95 % confidence interval [CI]: 0.35-0.61; p<0.001) and remained significant after multivariable adjustment for a comprehensive set of cardiovascular risk factors and potential confounders with a HR per 1-SD of 0.54 (95 % CI: 0.4-0.73; p<0.001). EPCs further demonstrated additional prognostic information indicated by improvements in C-statistic, net reclassification index and integrated discrimination increment. In conclusion, in our study circulating EPCs turned out as strong and independent inverse predictors of mortality underlining the importance of an impaired endothelial repair mechanism in the pathophysiology and progression of CHF.

Exercise-induced endothelial progenitor cell mobilization is attenuated in impaired glucose tolerance and type 2 diabetes

Circulating endothelial progenitor cells (EPCs) contribute to vascular homeostasis and are fewer in those with type 2 diabetes mellitus (T2DM) compared with normal glucose tolerance (NGT), suggesting a link between EPCs and T2DM-associated vasculopathies. The purpose of this study was to assess EPC number and mobilization by acute submaximal exercise in older adults with NGT, impaired glucose tolerance (IGT) or T2DM. We tested the hypothesis that EPC mobilization is lower in IGT compared with NGT and further reduced in older adults with T2DM. Forty-five older (50-75 yr of age) men and women with NGT (n = 18), IGT (n = 10), or T2DM (n = 17) were characterized and underwent submaximal aerobic exercise tests with blood sampling for enumeration of vascular endothelial growth factor receptor 2+ (VEGFR2+) cells, CD34+ hematopoetic progenitor cells, and CD34+/VEGFR2+ EPCs by flow cytometry before and after exercise. Basal EPC number was 65 and 61% lower in the IGT and T2DM groups, respectively, compared with the NGT group (P < 0.05). EPC number increased 23% after acute exercise in the NGT group (P < 0.01), but did not change in the IGT or T2DM groups. Before and after exercise, VEGFR2+ cell number was lower in a stepwise manner across the NGT, IGT, and T2DM groups (P < 0.05). Basal CD34+ cell number was lower in the IGT group compared with NGT (P < 0.05), but did not change after exercise in any group. These findings suggest a CD34+/VEGFR2+ EPC mobilization defect in IGT and T2DM that could play a role in the cardiovascular diseases and capillary rarefaction associated with insulin resistance.

Low-intensity treadmill exercise promotes rat dorsal wound healing

In order to investigate the promoting effect of low-intensity treadmill exercise on rat dorsal wound healing and the mechanism, 20 Sprague-Dawley rats were randomly divided into two groups: exercise group (Ex) and non-exercise group (non-ex). The rats in Ex group were given treadmill exercise for one month, and those in non-ex group raised on the same conditions without treadmill exercise. Both groups received dorsal wound operation with free access to food and water. By two-week continuous observation and recording of the wound area, the healing rate was analyzed. The blood sample was collected at day 14 post-operation via cardiac puncture for determination of the number of endothelial progenitor cells (EPCs) by flow cytometry, and the concentrations of relevant cytokines such as basic fibroblast growth factor (bFGF), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) were measured by ELISA. The skin tissue around the wound was dissected to observe the vascular density under the microscope after HE staining, to detect the mRNA level of VEGFR2 and angiopoietin-1 (Ang-1) receptor using RT-qPCR, and protein expression of a-smooth muscle actin (αSMA) and type III collagen (ColIII) using Western blotting. It was found that the wound area in Ex group was smaller at the same time point than in non-ex group. The number of circulating EPCs was greater and the concentrations of vasoactive factors such as VEGF, eNOS and bFGF were higher in Ex group than in non-ex group. HE staining displayed a higher vessel density in Ex group than in non-ex group. Moreover, the mRNA expression of VEGFR2 and Ang-1 detected in the wound tissue in Ex group was higher than in non-ex group. Meanwhile, the protein expression of αSMA and ColIII was more abundant in Ex group than in non-ex group. Conclusively, the above results demonstrate Ex rats had a higher wound healing rate, suggesting low-intensity treadmill exercise accelerates wound healing. The present work may provide some hint for future study of treating refractory wound.

Exercise Modulates Oxidative Stress and Inflammation in Aging and Cardiovascular Diseases

Despite the wealth of epidemiological and experimental studies indicating the protective role of regular physical activity/exercise training against the sequels of aging and cardiovascular diseases, the molecular transducers of exercise/physical activity benefits are not fully identified but should be further investigated in more integrative and innovative approaches, as they bear the potential for transformative discoveries of novel therapeutic targets. As aging and cardiovascular diseases are associated with a chronic state of oxidative stress and inflammation mediated via complex and interconnected pathways, we will focus in this review on the antioxidant and anti-inflammatory actions of exercise, mainly exerted on adipose tissue, skeletal muscles, immune system, and cardiovascular system by modulating anti-inflammatory/proinflammatory cytokines profile, redox-sensitive transcription factors such as nuclear factor kappa B, activator protein-1, and peroxisome proliferator-activated receptor gamma coactivator 1-alpha, antioxidant and prooxidant enzymes, and repair proteins such as heat shock proteins, proteasome complex, oxoguanine DNA glycosylase, uracil DNA glycosylase, and telomerase. It is important to note that the effects of exercise vary depending on the type, intensity, frequency, and duration of exercise as well as on the individual's characteristics; therefore, the development of personalized exercise programs is essential.

Effects of aerobic interval training and continuous training on cellular markers of endothelial integrity in coronary artery disease: a SAINTEX-CAD substudy

In this large multicenter trial, we aimed to assess the effect of aerobic exercise training in stable coronary artery disease (CAD) patients on cellular markers of endothelial integrity and to examine their relation with improvement of endothelial function. Two-hundred CAD patients (left ventricular ejection fraction > 40%, 90% male, mean age 58.4 ± 9.1 yr) were randomized on a 1:1 base to a supervised 12-wk rehabilitation program of either aerobic interval training or aerobic continuous training on a bicycle. At baseline and after 12 wk, numbers of circulating CD34+/KDR+/CD45dim endothelial progenitor cells (EPCs), CD31+/CD3+/CXCR4+ angiogenic T cells, and CD31+/CD42b− endothelial microparticles (EMPs) were analyzed by flow cytometry. Endothelial function was assessed by flow-mediated dilation (FMD) of the brachial artery. After 12 wk of aerobic interval training or aerobic continuous training, numbers of circulating EPCs, angiogenic T cells, and EMPs were comparable with baseline levels. Whereas improvement in peak oxygen consumption was correlated to improvement in FMD (Pearson r = 0.17, P = 0.035), a direct correlation of baseline or posttraining EPCs, angiogenic T cells, and EMP levels with FMD was absent. Baseline EMPs related inversely to the magnitude of the increases in peak oxygen consumption (Spearman rho = −0.245, P = 0.027) and FMD (Spearman rho = −0.374, P = 0.001) following exercise training. In conclusion, endothelial function improvement in response to exercise training in patients with CAD did not relate to altered levels of EPCs and angiogenic T cells and/or a diminished shedding of EMPs into the circulation. EMP flow cytometry may be predictive of the increase in aerobic capacity and endothelial function.

Vascular Ageing and Exercise: Focus on Cellular Reparative Processes

Ageing is associated with an increased risk of developing noncommunicable diseases (NCDs), such as diabetes and cardiovascular disease (CVD). The increased risk can be attributable to increased prolonged exposure to oxidative stress. Often, CVD is preceded by endothelial dysfunction, which carries with it a proatherothrombotic phenotype. Endothelial senescence and reduced production and release of nitric oxide (NO) are associated with “vascular ageing” and are often accompanied by a reduced ability for the body to repair vascular damage, termed “reendothelialization.” Exercise has been repeatedly shown to confer protection against CVD and diabetes risk and incidence. Regular exercise promotes endothelial function and can prevent endothelial senescence, often through a reduction in oxidative stress. Recently, endothelial precursors, endothelial progenitor cells (EPC), have been shown to repair damaged endothelium, and reduced circulating number and/or function of these cells is associated with ageing. Exercise can modulate both number and function of these cells to promote endothelial homeostasis. In this review we look at the effects of advancing age on the endothelium and these endothelial precursors and how exercise appears to offset this “vascular ageing” process.

Endothelial Progenitor Cell Levels Predict Future Physical Function: An Exploratory Analysis From the VA Enhanced Fitness Study

BACKGROUND

Levels of circulating progenitor cells (CPCs) are depleted with aging and chronic injury and are associated with level of physical functioning; however, little is known about the correlation of CPCs with longer-term measures of physical capabilities. We sought to determine the association of CPCs with future levels of physical function and with changes in physical function over time.

METHODS

CPCs were measured in 117 participants with impaired glucose tolerance in the Enhanced Fitness clinical trial based on the cell surface markers CD34 and CD133 and aldehyde dehydrogenase (ALDH) activity at baseline, 3 months, and 12 months. Physical function was assessed using usual and rapid gait speed, 6-minute walk distance, chair stand time, and SF-36 physical functioning score and reassessed at 3 and 12 months after clinical intervention.

RESULTS

Higher baseline levels of CD133(+), CD34(+), CD133(+)CD34(+), and ALDH(br) were each highly predictive of faster gait speed and longer distance walked in 6 minutes at both 3 and 12 months. These associations remained robust after adjustment for age, body mass index, baseline covariates, and inflammation and were independent of interventions to improve physical fitness. Further, higher CPC levels predicted greater improvements in usual and rapid gait speed over 1 year.

CONCLUSIONS

Baseline CPC levels are associated not only with baseline mobility but also with future physical function, including changes in gait speed. These findings suggest that CPC measurement may be useful as a marker of both current and future physiologic aging and functional decline.

Exercise and Stem Cells

Stem cells are traditionally studied in the context of embryonic development, yet studies confirm that a fraction remains in the adult organism for the purpose of daily remodeling and rejuvenation of multiple tissues following injury. Adult stem cells (ASCs) are found in close proximity to vessels and respond to tissue-specific cues in the microenvironment that dictate their fate and function. Exercise can dramatically alter strain sensing, extracellular matrix composition, and inflammation, and such changes in the niche likely alter ASC quantity and function postexercise. The field of stem cell biology is still in its infancy and identification and terminology of ASCs continues to evolve; thus, current information regarding exercise and stem cells is lacking. This chapter summarizes the literature that reports on the ASC response to acute exercise and exercise training, with particular emphasis on hematopoietic stem cells, endothelial progenitor cells, and mesenchymal stem cells.

Association between mobilization of circulating endothelial progenitor cells and time or degree of injury from angioplasty in patients with exertional angina: A prospective study

The aim of the present study was to investigate the effect of coronary artery angioplasty on the recruitment of circulating endothelial progenitor cells (EPCs) in patients with angina pectoris. A total of 66 patients treated by coronary stenting were enrolled in the PCI group and 17 patients that underwent angiography alone were enrolled in the control group. The EPC count in the blood was measured by flow cytometry prior to and at 1, 3, 5, 7 and 24 h following angioplasty in the percutaneous coronary intervention (PCI) group, and at three time-points following angiography in the control group. Differences between the two groups included the characteristics of the coronary artery lesions, the incidence of diabetes and family history of coronary heart disease. The mean surface area of the stent deployed was 335.59±234.99 mm². No significant change in EPC count was measured in the control group. In the PCI group, a moderate and delayed increase in the number of cluster of differentiation (CD)34⁺/kinase domain receptor (KDR)⁺ EPCs occurred at 24 h post-balloon inflation compared with the baseline level. The CD133^-/CD34⁺/KDR⁺ subpopulations showed undulating changes at 3, 7 and 24 h post-PCI (P=0.016, P=0.01 and P=0.032, respectively). An arch shape was displayed in CD133⁺/KDR⁺ cells; initially, a reduction occurred at 3 h and was maintained constantly until 7 h (P=0.003, P=0.013 and P=0.033 at 3, 5 and 7 h, respectively), after which a slight increase to the baseline level occurred at 24 h (P=0.084). The CD133⁺/CD34⁺ cells increased in stepwise manner until 24 h. The CD34⁺/KDR⁺ EPC change magnitude correlated significantly with a global damage index by partial correlation analysis (P<0.001). The results suggested that a time-dependent mobilization of EPCs may be initiated by PCI; the change magnitude of the CD34⁺/KDR⁺ cells was associated particularly with endothelial injury degree from the PCI procedure.