Acute and chronic effects of exercise on circulating endothelial progenitor cells in healthy and diseased patients

Maximal Exercise Improves the Levels of Endothelial Progenitor Cells in Heart Failure Patients

The impact of exercise on the levels of endothelial progenitor cells (EPCs), a marker of endothelial repair and angiogenesis, and circulating endothelial cells (CECs), an indicator of endothelial damage, in heart failure patients is largely unknown. This study aims to evaluate the effects of a single exercise bout on the circulating levels of EPCs and CECs in heart failure patients. Thirteen patients with heart failure underwent a symptom-limited maximal cardiopulmonary exercise test to assess exercise capacity. Before and after exercise testing, blood samples were collected to quantify EPCs and CECs by flow cytometry. The circulating levels of both cells were also compared to the resting levels of 13 volunteers (age-matched group). The maximal exercise bout increased the levels of EPCs by 0.5% [95% Confidence Interval, 0.07 to 0.93%], from 4.2 × 10−3 ± 1.5 × 10−3% to 4.7 × 10−3 ± 1.8 × 10−3% (p = 0.02). No changes were observed in the levels of CECs. At baseline, HF patients presented reduced levels of EPCs compared to the age-matched group (p = 0.03), but the exercise bout enhanced circulating EPCs to a level comparable to the age-matched group (4.7 × 10−3 ± 1.8 × 10−3% vs. 5.4 × 10−3 ± 1.7 × 10−3%, respectively, p = 0.14). An acute bout of exercise improves the potential of endothelial repair and angiogenesis capacity by increasing the circulating levels of EPCs in patients with heart failure.

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%VO_2max >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.

Impact of Non-Pharmacological Interventions on the Mechanisms of Atherosclerosis

Atherosclerosis remains the leading cause of mortality and morbidity worldwide characterized by the deposition of lipids and fibrous elements in the form of atheroma plaques in vascular areas which are hemodynamically overloaded. The global burden of atherosclerotic cardiovascular disease is steadily increasing and is considered the largest known non-infectious pandemic. The management of atherosclerotic cardiovascular disease is increasing the cost of health care worldwide, which is a concern for researchers and physicians and has caused them to strive to find effective long-term strategies to improve the efficiency of treatments by managing conventional risk factors. Primary prevention of atherosclerotic cardiovascular disease is the preferred method to reduce cardiovascular risk. Fasting, a Mediterranean diet, and caloric restriction can be considered useful clinical tools. The protective impact of physical exercise over the cardiovascular system has been studied in recent years with the intention of explaining the mechanisms involved; the increase in heat shock proteins, antioxidant enzymes and regulators of cardiac myocyte proliferation concentration seem to be the molecular and biochemical shifts that are involved. Developing new therapeutic strategies such as vagus nerve stimulation, either to prevent or slow the disease’s onset and progression, will surely have a profound effect on the lives of millions of people.

Endothelial Progenitor Cell Response to Acute Multicomponent Exercise Sessions with Different Durations

It is widely accepted that exercise training has beneficial effects on vascular health. Although a dose-dependent relation has been suggested, little is known about the effects of different exercise durations on endothelial markers. This study aimed to assess the effect of single exercise sessions with different durations in the circulating levels of endothelial progenitor cells (EPCs) and endothelial cells (CECs) among adults with cardiovascular risk factors. Ten participants performed two multicomponent exercise sessions, one week apart, lasting 30 and 45 min (main exercise phase). Before and after each exercise session, blood samples were collected to quantify EPCs and CECs by flow cytometry. The change in EPCs was significantly different between sessions by 3.0% (95% CI: 1.3 to 4.7), being increased by 1.8 ± 1.7% (p = 0.009) in the 30 min session vs. −1.2 ± 2.0% (p > 0.05) in the 45 min session. No significant change was observed in CECs [−2.0%, 95%CI: (−4.1 to 0.2)] between the sessions. In conclusion, a multicomponent exercise session of 30 min promotes an acute increase in the circulating levels of EPCs without increasing endothelial damage (measured by the levels of CECs) among adults with cardiovascular risk factors.

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.

Type 1 diabetes patients increase CXCR4+ and CXCR7+ haematopoietic and endothelial progenitor cells with exercise, but the response is attenuated

Exercise mobilizes angiogenic cells, which stimulate vascular repair. However, limited research suggests exercise-induced increase of endothelial progenitor cell (EPCs) is completely lacking in type 1 diabetes (T1D). Clarification, along with investigating how T1D influences exercise-induced increases of other angiogenic cells (hematopoietic progenitor cells; HPCs) and cell surface expression of chemokine receptor 4 (CXCR4) and 7 (CXCR7), is needed. Thirty T1D patients and 30 matched non-diabetes controls completed 45 min of incline walking. Circulating HPCs (CD34⁺, CD34⁺CD45^dim) and EPCs (CD34⁺VEGFR2⁺, CD34⁺CD45^dimVEGFR2⁺), and subsequent expression of CXCR4 and CXCR7, were enumerated by flow cytometry at rest and post-exercise. Counts of HPCs, EPCs and expression of CXCR4 and CXCR7 were significantly lower at rest in the T1D group. In both groups, exercise increased circulating angiogenic cells. However, increases was largely attenuated in the T1D group, up to 55% lower, with CD34⁺ (331 ± 437 Δcells/mL vs. 734 ± 876 Δcells/mL p = 0.048), CD34⁺VEGFR2⁺ (171 ± 342 Δcells/mL vs. 303 ± 267 Δcells/mL, p = 0.006) and CD34⁺VEGFR2⁺CXCR4⁺ (126 ± 242 Δcells/mL vs. 218 ± 217 Δcells/mL, p = 0.040) significantly lower. Exercise-induced increases of angiogenic cells is possible in T1D patients, albeit attenuated compared to controls. Decreased mobilization likely results in reduced migration to, and repair of, vascular damage, potentially limiting the cardiovascular benefits of exercise.Trial registration: ISRCTN63739203.

Effects of Different Types of Exercise Training on Endothelial Function in Prehypertensive and Hypertensive Individuals: A Systematic Review

BACKGROUND

Sustained high blood pressure can lead to vascular remodeling and endothelial cell injury, which may explain the endothelial dysfunction found in hypertensive individuals. Exercise training can improve vascular health in individuals with cardiovascular risk, but little is known about its effects in prehypertensive and hypertensive individuals.

OBJECTIVE

To review the literature showing evidence of changes in endothelial function in response to different modalities of exercise training in prehypertensive and hypertensive individuals.

METHODS

We conducted a systematic review of studies in the MEDLINE, Cochrane, LILACS, EMBASE, and SciELO databases following both the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and the PICO framework (patient/population, intervention, comparison and outcomes). Randomized clinical trials (RCTs) published up to April 2019 were selected and assessed by four independent reviewers. The methodological quality was assessed using the PEDro (Physiotherapy Evidence Database) scale.

RESULTS

Our search yielded 598 abstracts, and 10 studies were eligible for review. All of them had acceptable methodological quality by PEDro scale. Of the 10 studies, 7 involved aerobic training, 1 isometric resistance training, and 2 aerobic training and dynamic resistance training separately. Seven studies used flow-mediated dilation (FMD) to assess the vascular health, and three used plethysmography. Most training protocols involved hypertensive individuals and consisted of low and moderate-intensity exercise.

CONCLUSION

Our systematic review showed that moderate continuous aerobic training is effective to improve vascular health in hypertensive individuals. In prehypertensive individuals, vigorous interval aerobic training seems to be an alternative to determine vascular health benefits. Resistance exercise training, either isometric or dynamic, can be used as a secondary alternative, but still requires further investigation.

Individuals with controlled hypertension show endothelial integrity following a bout of moderate-intensity exercise: randomized clinical trial

To examine the acute effects of aerobic exercise (AE), resistance exercise (RE) or combined exercise (CE) on flow-mediated dilation (FMD), progenitor cells (PCs), endothelial progenitor cells (EPCs), oxidative stress markers and endothelial-cell derived microvesicles (EMVs) in patients with hypertension. This is a randomized, parallel-group clinical trial involving an intervention of one session of three different modalities of exercise. Thirty-three males (43 ± 2y) were randomly divided into three groups: a session of AE (n = 11, 40 min, cycle ergometer, 60% HRR); a session of RE (n = 11, 40 min, 4 × 12 lower limb repetitions, 60% 1-RM); or a session of CE (n = 11, 20-min RE + 20-min AE). FMD was assessed 10 min before and 10, 40 and 70 min post-intervention. Blood samples were collected at the same time points (except 40 min). FMD were similar in all groups and from baseline (within each group) after a single exercise bout (AE, RE or CE). At 70 min, RE group showed higher levels of PCs compared to the AE (81%) and CE group (60%). PC levels were reduced from baseline in all groups (AE: 32%, p = 0.037; RE: 15%, p = 0.003; CE: 17%, p = 0.048). The levels of EPCs, EMVs and oxidative stress were unchanged. There were no acute effects of moderate-intensity exercise on FMD, EPCs, EMVs and oxidative stress, but PCs decreased regardless of the exercise modality. Individuals with controlled hypertension do not seem to have impaired vascular function in response to a single exercise bout.

Changes in Circulating Stem and Progenitor Cell Numbers Following Acute Exercise in Healthy Human Subjects: a Systematic Review and Meta-analysis

Despite of the increasing number of investigations on the effects of acute exercise on circulating stem and progenitor cell (SC) numbers, and in particular on respective subgroups, i.e. endothelial (ESC), hematopoietic (HSC), and mesenchymal (MSC) stem and progenitor cells, a consensus regarding mechanisms and extent of these effects is still missing. The aim of this meta-analysis was to systematically evaluate the overall-effects of acute exercise on the different SC-subgroups and investigate possible subject- and intervention-dependent factors affecting the extent of SC-mobilization in healthy humans. Trials assessing SC numbers before and at least one timepoint after acute exercise, were identified in a systematic computerized search. Compared to baseline, numbers were significantly increased for early and non-specified SCs (enSCs) until up to 0.5 h after exercise (0–5 min: +0.64 [Standardized difference in means], p < 0.001; 6–20 min: +0.42, p < 0.001; 0.5 h: +0.29, p = 0.049), for ESCs until 12–48 h after exercise (0–5 min: +0.66, p < 0.001; 6–20 min: +0.43 p < 0.001; 0.5 h: +0.43, p = 0.002; 1 h: +0.58, p = 0.001; 2 h: +0.50, p = 0.002; 3–8 h: +0.70, p < 0.001; 12–48 h: +0.38, p = 0.003) and for HSCs at 0–5 min (+ 0.47, p < 0.001) and at 3 h after exercise (+ 0.68, p < 0.001). Sex, intensity and duration of the intervention had generally no influence. The extent and kinetics of the exercise-induced mobilization of SCs differ between SC-subpopulations. However, also definitions of SC-subpopulations are non-uniform. Therefore, finding a consensus with a clear definition of cell surface markers defining ESCs, HSCs and MSCs is a first prerequisite for understanding this important topic.

Effects of physical exercise on the prevention of stem cells senescence

Regular physical activity is essential for maintaining wellbeing; physical inactivity, on the contrary, is considered by the World Health Organization (WHO) as one of the most important risk factors for global mortality. During physical exercise different growth factors, cytokines and hormones are released, which affect positively the functions of heart, bone, brain and skeletal muscle. It has been reported that physical activity is able to stimulate tissue remodeling. Therefore, in this scenario, it is important to deepen the topic of physical activity-induced effects on stem cells.

Does High Volume of Exercise Training Increase Aseptic Vascular Inflammation in Male Athletes?

Aseptic vascular inflammation can be caused by high levels of various inflammatory and apoptotic factors such as tumor necrosis factor (TNFα), nitric oxide (NO), 3-nitrotyrosine (3-Nitro), and free and oxidized low-density lipoproteins (oxLDL) generated during intense exercise. Endothelial dysfunction resulting from enhanced inflammation has been implicated in cardiovascular disease (CVD). The purpose of the study was to observe the effects of high volume of exercise training on inflammatory mediators and their interaction with conventional CVD risk factors.

Blood samples were collected from highly-trained men (n = 16, 21.8 ± 4.0 years) as well as from nonactive men (n = 20, 21.1 ± 1.1 years). NO concentration did not differ between groups while TNFα, 3-Nitro, oxLDL, and CRP levels were significantly higher in athletes compared to nonathletes. TNFα reached even 7-fold higher level in athletes and was highly correlated with CVD risk factor such as TG, lipoproteins LDL and HDL as well as CRP. Approximately 50% of physically active men demonstrated a 20% increase in non-HDL caused by high levels of TC and LDL.

These findings suggest that athletes with a high exercise volume demonstrate increased levels of circulating biomarkers of vascular inflammation and may be more likely to have CVD.

Moderate exercise has beneficial effects on mouse ischemic stroke by enhancing the functions of circulating endothelial progenitor cell-derived exosomes

Exosomes (EXs) are emerging as novel players in the beneficial effects induced by exercise on vascular diseases. We have recently revealed that moderate exercise enhances the function of circulating endothelial progenitor cell-derived EXs (cEPC-EXs) on protecting endothelial cells against hypoxia injury. However, the relationship between the changes of cEPC-EXs and the effects of exercise on ischemic stroke (IS) is unknown. Here, we investigated whether exercise-regulated EPC-EXs contribute to the beneficial effects of exercise on IS. C57BL/6 mice received moderate treadmill exercise (10 m/min) for 4-wks and then were subjected to middle cerebral artery occlusion (MCAO) stroke. The neurologic deficit score (NDS), infarct volume, microvessel density, cell apoptosis, angiogenesis/neurogenesis, sensorimotor functions were determined on day 2 (acute stage) and/or day 28 (chronic stage) post-stroke. The miR-126 and EPC-EX levels were analyzed by RT-PCR or nanoparticle tracking analysis combined with microbeads and used for correlation analyses. The function of EPC-EXs from exercised mice was detected in a hypoxia neuron model. Cell apoptosis, axon growth ability and gene expressions (cas-3 and Akt) were measured. Our data showed that: i) On day 2, exercised mice had decreased NDS and infarct volume, reduced cell apoptosis rate and cleaved cas-3 level, and a higher microvessel density than those in control (no-exercise) mice. The levels of EPC-EXs in plasma and brain tissue were raised and positively correlated in exercised mice. Meanwhile, the miR-126 level in cEPC-EXs and in ischemic tissue were upregulated in exercised mice. The EPC-EXs and their carried miR-126 levels negatively correlated with the infarct volume and cell apoptosis, whereas positively correlated with microvessel density. In addition, cEPC-EXs from exercised mice elicited protective effects on neurons against hypoxia-induced apoptosis and compromised axon growth ability which were blocked by miR-126 and PI3k inhibitors in vitro. ii) On day 28, exercised mice had less infarct volume, higher microvessel density, angiogenesis/neurogenesis and better sensorimotor functions. The levels of BDNF, p-TrkB/TrkB and p-Akt/Akt were upregulated in the brain of exercised mice. These recovery indexes correlated with the levels of cEPC-EXs and their miR-126. In conclusion, our data suggest that moderate exercise intervention has protective effects on the brain against MCAO-induced ischemic injury in both acute and chronic stages which might via the release of miR-126 enriched EPC-EXs.

Effect of Aerobic and Resistance Training on Endothelial Progenitor Cells in Mice with Type 2 Diabetes

Since no study has explored whether exercise could improve impaired proliferation, migration, and angiogenesis of endothelial progenitor cells (EPCs) in animal models or humans with type 2 diabetes, we aimed to explore the effect of different models of exercise on EPC function and expression of caveolin-1, PI3K, and AKT in mice with type 2 diabetes. Male db/db mice (age: 8 weeks) with type 2 diabetes were subjected to aerobic training (AT), resistance training (RT), or combined aerobic and resistance training (AT+RT) 3 or 4 days/week. Mice in the control group remained sedentary with no specific training requirement. Bone marrow-derived EPCs were isolated, and the protein concentrations of caveolin-1, Pi3k, and AKT, and EPC function, were identified in the 1st, 4th, 8th, and 12th weeks of the intervention. Greater increases in proliferation, migration, and angiogenesis were observed in the AT, RT, and AT+RT groups than in the control group. AT+RT was more effective than AT or RT in improving the migratory and angiogenesis function of EPCs in mice with type 2 diabetes and achieved maximum improvement after 8 weeks of intervention. Western blot analysis showed that caveolin-1, p-PI3k, and p-Akt levels were obviously increased in the AT, RT, and AT+RT groups compared with the control group. The expression level of these proteins in the AT+RT group was higher than that in the AT and RT groups. AT+RT may be a helpful reference when choosing exercise methods for the prevention of diabetes-related cardiovascular diseases.

Physical activity intervention improved the number and functionality of endothelial progenitor cells in low birth weight children

BACKGROUND AND AIMS

The purpose of this study was to investigate whether an intervention with physical activity (PA) would promote positive effects on the angiogenic factors, mobilization, and functionality of circulating endothelial progenitor cells (EPCs) in children with low birth weight (LBW).

METHODS AND RESULTS

Thirty-five children participated in a 10-week PA program (intensity: 75-85% of heart rate reserve, frequency: four times/week, and duration: 45 min). Before and after the PA program, we evaluated anthropometric parameters, blood pressure levels, biochemical profile, number of EPCs, number of EPC colony forming units, and plasma levels of vascular endothelial growth factor-A (VEGF-A), nitric oxide (NO), and matrix metalloproteinases (MMPs) 2 and 9. We found a significant main effect of the PA program on waist circumference (η_p² = 0.489), cardiorespiratory fitness (η_p² = 0.463), and MMP-9 (η_p² = 0.582). Birth weight or the PA program produced significant independent effects on systolic blood pressure (birth weight: η_p² = 0.431; PA program: η_p² = 0.615) and EPC colony forming units (birth weight: η_p² = 0.541; PA program: η_p² = 0.698) with no significant interactions. The combination of birth weight and the PA program produced a significant interaction effect on the number of circulating EPCs (η_p² = 0.123), NO (η_p² = 0.258), and VEGF-A (η_p² = 0.175). The variation in the number of EPCs from baseline to 10 weeks of the PA program correlated positively with the change in NO (P = 0.002) and VEGF-A (P = 0.004).

CONCLUSIONS

A 10-week PA program attenuates the adverse effect of LBW on the number and functionality of EPCs; this effect occurs through an improvement in circulating levels of NO and VEGF-A. CLINICAL TRIALS: https://www.clinicaltrials.gov. Unique Identifier: NCT02982967. Date: December/2016.

Endothelial Dysfunction in Chronic Heart Failure: Assessment, Findings, Significance, and Potential Therapeutic Targets

Chronic heart failure (CHF) is a complex syndrome that results from structural and functional disturbances that affect the ability of the heart to supply oxygen to tissues. It largely affects and reduces the patient's quality of life, socio-economic status, and imposes great costs on health care systems worldwide. Endothelial dysfunction (ED) is a newly discovered phenomenon that contributes greatly to the pathophysiology of numerous cardiovascular conditions and commonly co-exists with chronic heart failure. However, the literature lacks clarity as to which heart failure patients might be affected, its significance in CHF patients, and its reversibility with pharmacological and non-pharmacological means. This review will emphasize all these points and summarize them for future researchers interested in vascular pathophysiology in this particular patient population. It will help to direct future studies for better characterization of these two phenomena for the potential discovery of therapeutic targets that might reduce future morbidity and mortality in this "at risk" population.

High-intensity interval training followed by postexercise cold-water immersion does not alter angiogenic circulating cells, but increases circulating endothelial cells

High-intensity interval training (HIIT) induces vascular adaptations that might be attenuated by postexercise cold-water immersion (CWI). Circulating angiogenic cells (CAC) participate in the vascular adaptations and circulating endothelial cells (CEC) indicate endothelial damage. CAC and CEC are involved in vascular adaptation. Therefore, the aim of the study was to investigate postexercise CWI during HIIT on CAC and CEC and on muscle angiogenesis-related molecules. Seventeen male subjects performed 13 HIIT sessions followed by 15 min of passive recovery (n = 9) or CWI at 10 °C (n = 8). HIIT comprised cycling (8-12 bouts, 90%-110% peak power). The first and the thirteenth sessions were similar (8 bouts at 90% of peak power). Venous blood was drawn before exercise (baseline) and after the recovery strategy (postrecovery) in the first (pretraining) and in the thirteenth (post-training) sessions. For CAC and CEC identification lymphocyte surface markers (CD133, CD34, and VEGFR2) were used. Vastus lateralis muscle biopsies were performed pre- and post-training for protein (p-eNOS^ser1177) and gene (VEGF and HIF-1) expression analysis related to angiogenesis. CAC was not affected by HIIT or postexercise CWI. Postexercise CWI increased acute and baseline CEC number. Angiogenic protein and genes were not differently modulated by post-CWI. HIIT followed by either recovery strategy did not alter CAC number. Postexercise CWI increased a marker of endothelial damage both acutely and chronically, suggesting that this postexercise recovery strategy might cause endothelial damage. Novelty HIIT followed by CWI did not alter CAC. HIIT followed by CWI increased CEC. Postexercise CWI might cause endothelial damage.

Platelet‑derived growth factor D promotes the angiogenic capacity of endothelial progenitor cells

Neovascularization and re-endothelialization rely on endothelial progenitor cells (EPCs). However, the recruitment and angiogenic roles of EPCs are subject to regulation through the vascular microenvironment, which remains largely unknown. Platelet-derived growth factor D (PDGF-D) is a new member of the PDGF family that binds the PDGFR-β homodimer. However, it remains unknown whether and how it affects the angiogenic capacity of EPCs and participates in tube-like formation. EPCs were derived from rat bone marrow cells, and the gain-of-function approach was used to study the effects of PDGF-D on the biological activities of EPCs. EPCs that stably express PDGF-D were generated by lentiviral-mediated transduction, and the expression levels were evaluated by western blotting and reverse transcription, followed by real-time quantitative polymerase chain reaction (RT-qPCR). The biological activities of EPCs evaluated in the present study included proliferation, adhesion, migration, tube formation and senescence. Furthermore, the downstream signaling of PDGF-D was explored by western blot analysis. The results revealed that the lentiviral-mediated expression of PDGF-D in the microenvironment promoted the migration, proliferation, adhesion and tube formation of EPCs. In addition, PDGF-D suppressed the senescence of EPCs. Mechanistically, PDGF-D induced the phosphorylation of several signaling molecules, including STAT3, AKT, ERK1/2, mTOR and GSK-3β, suggesting that PDGF-D enhanced the angiogenic function of EPCs through PDGF receptor-dependent and -independent signaling pathways. In conclusion, PDGF-D promotes the angiogenic capacity of EPCs, including proliferation, migration, adhesion and tube formation, and thereby contributes to angiogenesis.

Endothelial progenitor cells and rheumatic disease modifying therapy

Rheumatic diseases are associated with accelerated atherosclerosis and with increased risk of cardiovascular morbidity and mortality. The mechanisms underlying the higher prevalence of cardiovascular disease are not completely clarified, but it is likely that a pivotal role is played by vascular inflammation and consequently to altered vascular endothelium homeostasis. Also, high prevalence of traditional risk factors, proatherogenic activation and endothelial dysfunction further contribute to vascular damage. Circulating endothelial progenitor cells (EPCs) can restore dysfunctional endothelium and protect against atherosclerotic vascular disease. However, abnormalities in number and function of these cells in patients with rheumatic condition have been extensively reported. During the last years, growing interest in the mechanisms of endothelial renewal and its potential as a therapy for CVD has been shown; in addition, pioneering studies show that EPC dysfunction might be improved with pharmacological strategies. However, how to restore EPC function, and whether achieving this aim may be effective in preventing cardiovascular complications in rheumatic disease, remain to be established. In this review we report an overview on the current stand of knowledge on the effect of pharmaceutical and lifestyle intervention in improving EPCs number and function in rheumatic disease.

MicroRNAs Mediate Beneficial Effects of Exercise in Heart

MicroRNAs (miRNAs, miRs), a group of small non-coding RNAs, repress gene expressions at posttranscriptional level in most cases and are involved in cardiovascular physiology and disease pathogenesis. Increasing evidence has proved that miRNAs are potential regulators of exercise induced cardiac growth and mediate the benefits of exercise in a variety of cardiovascular diseases. In this chapter, we will review the regulatory effects of miRNAs in cardiac adaptations to exercise, and summarize their cardioprotective effects against myocardial infarction, ischemia/reperfusion injury, heart failure, diabetic cardiomyopathy, atherosclerosis, hypertension, and pulmonary hypertension. Also, we will introduce circulating miRNAs in response to acute and chronic exercise. Therefore, miRNAs may serve as novel therapeutic targets and potential biomarkers for cardiovascular diseases.

Effects of resistance exercise on endothelial progenitor cell mobilization in women

This study aimed to determine the effect of a single bout of resistance exercise at different intensities on the mobilization of circulating EPCs over 24 hours in women. In addition, the angiogenic factors stromal cell-derived factor 1 (SDF-1α), vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1-alpha (HIF-1α) and erythropoietin (EPO) were measured as potential mechanisms for exercise-induced EPCs mobilization. Thirty-eight women performed a resistance exercise session at an intensity of 60% (n = 13), 70% (n = 12) or 80% (n = 13) of one repetition maximum. Each session was comprised of three sets of 12 repetitions of four exercises: bench press, dumbbell curl, dumbbell squat, and standing dumbbell upright row. Blood was sampled at baseline and immediately, 6 hours, and 24 hours post-exercise. Circulating EPC and levels of VEGF, HIF-1α and EPO were significantly higher after exercise (P < 0.05). The change in EPCs from baseline was greatest in the 80% group (P < 0.05), reaching the highest at 6 hours post-exercise. The change in EPCs from baseline to 6 hours post-exercise was correlated with the change in VEGF (r = 0.492, P = 0.002) and HIF-1α (r = 0.388, P = 0.016). In general, a dose-response relationship was observed, with the highest exercise intensities promoting the highest increases in EPCs and angiogenic factors.

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.

Tumor Necrosis Factor α Regulates Endothelial Progenitor Cell Migration via CADM1 and NF-kB

Shortly after the discovery of endothelial progenitor cells (EPCs) in 1997, many clinical trials were conducted using EPCs as a cellular based therapy with the goal of restoring damaged organ function by inducing growth of new blood vessels (angiogenesis). Results were disappointing, largely because the cellular and molecular mechanisms of EPC-induced angiogenesis were not clearly understood. Following injection, EPCs must migrate to the target tissue and engraft prior to induction of angiogenesis. In this study EPC migration was investigated in response to tumor necrosis factor α (TNFα), a pro-inflammatory cytokine, to test the hypothesis that organ damage observed in ischemic diseases induces an inflammatory signal that is important for EPC homing. In this study, EPC migration and incorporation were modeled in vitro using a coculture assay where TNFα treated EPCs were tracked while migrating toward vessel-like structures. It was found that TNFα treatment of EPCs increased migration and incorporation into vessel-like structures. Using a combination of genomic and proteomic approaches, NF-kB mediated upregulation of CADM1 was identified as a mechanism of TNFα induced migration. Inhibition of NF-kB or CADM1 significantly decreased migration of EPCs in vitro suggesting a role for TNFα signaling in EPC homing during tissue repair. Stem Cells 2016;34:1922-1933.

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

Cardiovascular disease risk increases with age due, in part, to impaired endothelial function and decreased circulating angiogenic cell (CAC) number and function. We sought to determine if 10 days of aerobic exercise training improves endothelial function, CAC number, and intracellular redox balance in older sedentary adults. Eleven healthy subjects (4 men, 7 women), 61 ± 2 years of age participated in 60 min of aerobic exercise at 70% maximal oxygen consumption for 10 consecutive days while maintaining body weight. Before and after training, endothelial function was measured as flow-mediated dilation of the brachial artery and fasting blood was drawn to enumerate 3 CAC subtypes. Intracellular reactive oxygen species (ROS) and nitric oxide (NO) in CD34+ CACs were measured using fluorescent probes and reinforced via real-time quantitative polymerase chain reaction. Flow-mediated dilation improved significantly following training (10% ± 1.3% before vs. 16% ± 1.4% after training; P < 0.05). Likewise, CD34+/KDR+ number increased 104% and KDR+ number increased 151% (P < 0.05 for both), although CD34+ number was not significantly altered (P > 0.05). Intracellular NO and ROS levels in CD34+ CACs were not different after training (P > 0.05 for both). Messenger RNA expression of SOD1, endothelial nitric oxide synthase, and NADPH oxidase 2 and neutrophil cytosolic factor 1 in CD34+ CACs was not significantly altered with training (P > 0.05). In conclusion, 10 consecutive days of aerobic exercise increased flow-mediated dilation and CAC number in older, previously sedentary adults, but did not affect intracellular redox balance in CD34+ CACs. Overall, these data indicate that even short-term aerobic exercise training can have a significant impact on cardiovascular disease risk factors.

Endothelial progenitor cells (EPCs) in ageing and age-related diseases: How currently available treatment modalities affect EPC biology, atherosclerosis, and cardiovascular outcomes

Endothelial progenitor cells (EPCs) are mononuclear cells that circulate in the blood and are derived from different tissues, expressing cell surface markers that are similar to mature endothelial cells. The discovery of EPCs has lead to new insights in vascular repair and atherosclerosis and also a new theory for ageing. EPCs from the bone marrow and some other organs aid in vascular repair by migrating to distant vessels where they differentiate into mature endothelial cells and replace old and injured endothelial cells. The ability of EPCs to repair vascular damage depends on their number and functionality. Currently marketed drugs used in a variety of diseases can modulate these characteristics. In this review, the effect of currently available treatment options for cardiovascular and metabolic disorders on EPC biology will be discussed. The various EPC-based therapies that will be discussed include lipid-lowering agents, antihypertensive agents, antidiabetic drugs, phosphodiesteraze inhibitors, hormones, as well as EPC capturing stents.

Study of endothelial function response to exercise training in hypertensive individuals (SEFRET): study protocol for a randomized controlled trial

Background

Endothelial dysfunction is a hallmark of diabetes mellitus and systemic arterial hypertension (SAH) and an early maker for atherosclerosis. Aerobic exercise training is known to enhance endothelial function, but little is understood about the effects of resistance or combined exercise training on endothelial function. The aim of this study is to investigate the effect of a 12-week aerobic (AT), resistance (RT), or combined (aerobic and resistance, CT) training program on endothelial function and assess associated effects on blood pressure in individuals with SAH.

Methods/design

Eighty-one subjects with SAH aged 18 to 70 years will be selected and randomly assigned to three types of exercise training: AT, RT or CT. The study will involve the following procedures and tests: anamnesis, anthropometric assessment, echocardiography, blood pressure measurements through ambulatory blood pressure monitoring, flow-mediated dilation, ergospirometry, one repetition maximum test (1-RM), and blood collection (number of circulating endothelial progenitor cells, number of circulating endothelial microparticles, lipid profile, glucose, glycated hemoglobin, and creatinine). The AT intervention will consist of a 40-min exercise session with progressive intensities ranging from 50 to 75 % of heart rate reserve. The RT intervention will consist of a 40-minute session with four sets of six to 12 repetitions with a rest period of 60 to 90 seconds between each set and each type of exercise. Weight loads will be adjusted to 60 to 80 % of 1-RM for six types of exercise. The CT intervention will consist of a 20-min aerobic exercise session, followed by an additional 20-min resistance exercise session; each resistance exercise will have two sets less to match the total training volume.

Discussion

The study results are expected evidence of cardiovascular protective effects of different types of exercise training through the modulation of endothelial function in hypertensive individuals. Knowing the magnitude of improvement of endothelium-dependent vasodilation for the different types of exercise training can provide scientific evidence for the prescription of exercise programs for vascular protection targeting hypertensive individuals.

Trial registration

The Brazilian Clinical Trials Registry (http://www.ensaiosclinicos.gov.br/) under RBR-9ygmdn and dated 1 March 2015.

[Prevention of cardiovascular diseases through sport and physical activity: A question of intensity?]

Coronary artery disease is the leading cause of death worldwide. A sedentary lifestyle accounts for 9% of premature mortality and creates a substantial health economic burden. Measurement of physical activity in daily practice refers to metabolic equivalent tasks and assessment of cardiopulmonary fitness to measurements of peak oxygen uptake during ergometry, which can be used to classify an individual's physical activity and maximum exercise capacity. Physical activity is a multifunctional intervention tool in prevention, which exerts its effects on multiple biochemical pathways, in contrast to conventional drug therapy. These changes reduce cardiovascular morbidity and mortality. Moderate physical exercise reduces blood pressure, improves insulin sensitivity and dyslipidemia, improves body composition and enhances weight reduction. Exercise of higher intensity seems to have superior effects compared to moderate intensity training; however, the training volume also seems to be important, as negative effects of long-term intensive training have been reported, e.g. atrial fibrillation or coronary sclerosis. Overall, exercise training has a major role in primary prevention of cardiovascular disease but seems to have a maximum threshold for benefit, which may be exceeded by some individuals.

Influence of exercise training on proangiogenic TIE-2 monocytes and circulating angiogenic cells in patients with peripheral arterial disease

BACKGROUND

Inflammation is the driving force in atherosclerosis. One central strategy in the treatment of peripheral arterial disease (PAD) is the promotion of angiogenesis. Here, proangiogenic Tie-2 expressing monocytes (TEM) and circulating angiogenic cells (CAC) play a crucial role. Exercise training (ET) is recommended in PAD patients at Fontaine stage II to promote angiogenesis.

METHODS

40 patients with intermittend claudication (IC) [2 groups: supervised ET (SET) vs. non-supervised ET (nSET), each n = 20] and 20 healthy controls were included in the study. Analysis of TEM and CAC was performed from whole blood by flow-cytometry. TEM were identified via CD45, CD86, CD14, CD16 and analysed for the expression of Tie-2. CAC were identified via their expression of CD45 (CD45dim), CD34 and VEGF-R2 (CD309/KDR). Follow up was performed after mean of 7.65 ± 1.62 months.

RESULTS

In comparison to healthy controls, we found increased proportions of CAC (p < 0.0001) and similar TEM numbers in both ET groups. At follow-up (FU) TEM poroportions increased (p < 0.001) and CAC proportions decreased (p < 0.01), but both more significantly in SET (p < 0.001) than nSET (p = 0.01). Only in SET fibrinogen levels decreased and VEGF-A increased (both p < 0.05). Finally, we found in both ET groups a significant increase in absolute walking distance but with a higher individual increase in SET (p < 0.01). TEM and CAC proportions correlated inversely with the absolute walking distance (CAC: r = -0.296, p = 0.02; TEM: r = -0.270, p = 0.04) as well as with ABI (CAC: r = -0.394, p < 0.01; TEM: r = -0.382, p < 0.01).

CONCLUSIONS

ET influences the distribution of CAC and TEM proportions. nSET, although still effective in regard to an improved walking distance, is less effective in the influence of proangiogenic cells and inflammatory burden than SET. Our results indicate SET to be a more preferential exercise form, supporting the necessity to establish more SET programs.

The influence of hypoxic physical activity on cfDNA as a new marker of vascular inflammation

The phenomenon of circulating cell-free DNA (cfDNA) is important for many biomedical disciplines including the field of exercise biochemistry and physiology. It is likely that cfDNA is released into the plasma by apoptosis of endothelial cells and circulating endothelial progenitor cells (EPCs), and/or by NETosis of immune cells induced by strenuous exercise. Increases of cfDNA are described to be a potential hallmark for the overtraining syndrome, and might be related to aseptic vascular inflammation in athletes. Yet, the relevance of systemic inflammation and cfDNA with endothelial dysfunction in athletes still remains unclear. In this review article, we provide a current overview of exercise-induced cfDNA release to the circulation with special emphasis on its relationship with apoptosis and NETosis and the effect of hypoxic physical activity on vascular inflammation in athletes.

Endurance Exercise Mobilizes Developmentally Early Stem Cells into Peripheral Blood and Increases Their Number in Bone Marrow: Implications for Tissue Regeneration

Endurance exercise has been reported to increase the number of circulating hematopoietic stem/progenitor cells (HSPCs) in peripheral blood (PB) as well as in bone marrow (BM). We therefore became interested in whether endurance exercise has the same effect on very small embryonic-like stem cells (VSELs), which have been described as a population of developmentally early stem cells residing in BM. Mice were run daily for 1 hour on a treadmill for periods of 5 days or 5 weeks. Human volunteers had trained in long-distance running for one year, six times per week. FACS-based analyses and RT-PCR of murine and human VSELs and HSPCs from collected bone marrow and peripheral blood were performed. We observed that endurance exercise increased the number of VSELs circulating in PB and residing in BM. In parallel, we observed an increase in the number of HSPCs. These observations were subsequently confirmed in young athletes, who showed an increase in circulating VSELs and HSPCs after intensive running exercise. We provide for the first time evidence that endurance exercise may have beneficial effects on the expansion of developmentally early stem cells. We hypothesize that these circulating stem cells are involved in repairing minor exercise-related tissue and organ injuries.

Effects of acute exercise on circulating endothelial and progenitor cells in children and adolescents with juvenile idiopathic arthritis and healthy controls: a pilot study

BACKGROUND

Youth with juvenile idiopathic arthritis (JIA) may be at risk of poor cardiovascular health. Circulating endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are markers of cardiovascular repair and damage, respectively, and respond to exercise. The objectives of this study were to compare resting levels of EPCs and CECs in JIA and controls, and to assess the effects of distinct types of exercise on EPCs and CECs in JIA and controls.

METHODS

Seven youth with JIA and six controls completed 3 visits. First, aerobic fitness was assessed. Participants then performed either moderate intensity, continuous exercise (MICE) or high intensity, intermittent exercise (HIIE) on separate days. Blood samples were collected at the beginning (REST), mid-point (MID) and end of exercise (POST) for determination of EPCs (CD31(+)CD34(bright)CD45(dim)CD133(+)) and CECs (CD31(bright)CD34(+)CD45(-)CD133(-)) by flow cytometry. Between group differences in EPCs and CECs were examined using two-way ANOVA, followed by Tukey's HSD post hoc, where appropriate. Statistical significance set at p ≤ 0.05.

RESULTS

Both EPCs and CECs were similar between groups at REST (p = 0.18-0.94). During MICE, EPCs remained unchanged in JIA (p = 0.95) but increased significantly at POST in controls (REST: 0.91 ± 0.55 × 10(6) cells/L vs. POST: 1.53 ± 0.36 × 10(6) cells/L, p = 0.04). Compared with controls, lower levels of EPCs were observed in JIA at MID (0.48 ± 0.50 × 10(6) cells/L vs. 1.10 ± 0.39 × 10(6) cells/L, p = 0.01) and POST (0.38 ± 0.34 × 10(6) cells/L vs. 1.53 ± 0.36 × 10(6) cells/L, p < 0.001) during MICE. No changes were detected in CECs with MICE in JIA and controls (p = 0.69). Neither EPCs nor CECs were modified with HIIE (p = 0.28-0.69).

CONCLUSION

Youth with JIA demonstrated a blunted EPC response to MICE when compared with controls. Future work should examine factors that may increase or normalize EPC mobilization in JIA.

The inflammation, vascular repair and injury responses to exercise in fit males with and without Type 1 diabetes: an observational study

BACKGROUND

Type 1 diabetes is associated with raised inflammation, impaired endothelial progenitor cell mobilisation and increased markers of vascular injury. Both acute and chronic exercise is known to influence these markers in non-diabetic controls, but limited data exists in Type 1 diabetes. We assessed inflammation, vascular repair and injury at rest and after exercise in physically-fit males with and without Type 1 diabetes.

METHODS

Ten well-controlled type 1 diabetes (27 ± 2 years; BMI 24 ± 0.7 kg.m(2); HbA1c 53.3 ± 2.4 mmol/mol) and nine non-diabetic control males (27 ± 1 years; BMI 23 ± 0.8 kg.m(2)) matched for age, BMI and fitness completed 45-min of running. Venous blood samples were collected 60-min before and 60-min after exercise, and again on the following morning. Blood samples were processed for TNF-α using ELISA, and circulating endothelial progenitor cells (cEPCs; CD45(dim)CD34(+)VEGFR2(+)) and endothelial cells (cECs; CD45(dim)CD133(-)CD34(+)CD144(+)) counts using flow-cytometry.

RESULTS

TNF-α concentrations were 4-fold higher at all-time points in Type 1 diabetes, when compared with control (P < 0.001). Resting cEPCs were similar between groups; after exercise there was a significant increase in controls (P = 0.016), but not in Type 1 diabetes (P = 0.202). CEPCs peaked the morning after exercise, with a greater change in controls vs. Type 1 diabetes (+139 % vs. 27 %; P = 0.01). CECs did not change with exercise and were similar between groups at all points (P > 0.05). Within the Type 1 diabetes group, the delta change in cEPCS from rest to the following morning was related to HbA1c (r = -0.65, P = 0.021) and TNF-α (r = -0.766, P = 0.005).

CONCLUSIONS

Resting cEPCs and cECs in Type 1 diabetes patients with excellent HbA1c and high physical-fitness are comparable to healthy controls, despite eliciting 4-fold greater TNF-α. Furthermore, Type 1 diabetes patients appear to have a blunted post-exercise cEPCs response (vascular repair), whilst a biomarker of vascular injury (cECs) remained comparable to healthy controls.

Association between muscular strength and inflammatory markers among elderly persons with cardiac disease: results from the KORA-Age study

Little is known about the association between muscle strength and inflammation in diseased individuals and particularly in cardiac patients. Thus, our purpose was to examine the association of muscular strength with the inflammatory status in older adults with and without cardiac disease. The cross-sectional analysis was based on 1079 adults aged 65-94 years, who participated in the KORA-Age study. Participants underwent an interview and extensive physical examinations including anthropometric measurements, registration of diseases and drug intake, determination of health-related behaviors, collection of blood samples for measurements of interleukin-6 and hs-CRP and muscle strength measurement using hand-grip dynamometry. Cardiac patients (n = 323) had higher levels of IL-6 and poorer muscle strength compared with older adults without cardiac disease. Among persons with cardiac diseases, muscle strength in the lower tertile compared to the upper tertile was significantly associated with increased odds of having elevated IL-6 levels (OR 3.53, 95 % CI 1.18-10.50, p = 0.024) after controlling for age, gender, body fat, alcohol intake, smoking status, diseases, medications and physical activity, whereas the association between muscle strength and hs-CRP remained borderline significant (OR 2.80, 95 % CI 0.85-9.24, p = 0.092). The same trends, with slightly lower odds ratios, were also observed in older adults without cardiac disease. Lower levels of muscular strength are associated with higher concentrations of IL-6 and hs-CRP in elderly individuals with and without cardiac disease suggesting a significant contribution of the muscular system in reducing low-grade inflammation that accompanies cardiac disease and aging.

Effect of Moderate Aerobic Exercise Training on Endothelial Function and Arterial Stiffness in CKD Stages 3-4: A Randomized Controlled Trial

BACKGROUND

Evidence of a beneficial effect of exercise training on mediators of vascular disease is accumulating in chronic kidney disease (CKD), but its effect on vascular function in vivo still has to be established. The present study was designed to investigate whether a formal aerobic exercise training program improves peripheral endothelial function in patients with CKD stages 3 to 4.

STUDY DESIGN

Randomized controlled trial with a parallel-group design.

SETTING & PARTICIPANTS

48 patients with CKD stages 3 to 4 without established cardiovascular disease were randomly assigned to either an exercise training program or usual care. 40 patients completed the study (exercise training, 19; usual care, 21).

INTERVENTION

The 3-month home-based aerobic training program consisted of 4 daily cycling sessions of 10 minutes each at a target heart rate, calculated as 90% of the heart rate achieved at the anaerobic threshold. Patients in the usual-care group were given standard therapy.

OUTCOMES

The primary outcome was peripheral endothelial function. Secondary outcomes were aerobic capacity, arterial stiffness, numbers of endothelial (EPCs) and osteogenic progenitor cells (OPCs), migratory function of circulatory angiogenic cells, and health-related quality of life.

MEASUREMENTS

Endothelial function was assessed with flow-mediated dilation of the brachial artery, aerobic capacity by peak oxygen uptake (VO(2peak)), arterial stiffness by carotid-femoral pulse wave velocity, numbers of EPCs and OPCs by flow cytometry, circulatory angiogenic cell function by an in vitro migratory assay, and quality of life by the Kidney Disease Quality of Life-Short Form questionnaire.

RESULTS

Exercise training significantly improved VO(2peak) and quality of life, but not in vivo vascular function (flow-mediated dilation and carotid-femoral pulse wave velocity) or cellular markers for vascular function (EPC and OPC count and circulatory angiogenic cell migratory function).

LIMITATIONS

Short duration and intermittent nature of the exercise intervention.

CONCLUSIONS

In patients with CKD stages 3 to 4 without overt cardiovascular disease, 3 months of aerobic exercise training improved VO(2peak) and quality of life, without altering endothelial function or arterial stiffness.

Leukocyte telomere length and left ventricular function after acute ST-elevation myocardial infarction: data from the glycometabolic intervention as adjunct to primary coronary intervention in ST elevation myocardial infarction (GIPS-III) trial

Background

Telomere length has been associated with coronary artery disease and heart failure. We studied whether leukocyte telomere length is associated with left ventricular ejection fraction (LVEF) after ST-elevation myocardial infarction (STEMI).

Methods and results

Leukocyte telomere length (LTL) was determined using the monochrome multiplex quantitative PCR method in 353 patients participating in the glycometabolic intervention as adjunct to primary percutaneous coronary intervention in STEMI III trial. LVEF was assessed by magnetic resonance imaging. The mean age of patients was 58.9 ± 11.6 years, 75 % were male. In age- and gender-adjusted models, LTL at baseline was significantly associated with age (beta ± standard error; −0.33 ± 0.01; P < 0.01), gender (0.15 ± 0.03; P < 0.01), TIMI flow pre-PCI (0.05 ± 0.03; P < 0.01), TIMI flow post-PCI (0.03 ± 0.04; P < 0.01), myocardial blush grade (−0.05 ± 0.07; P < 0.01), serum glucose levels (−0.11 ± 0.01; P = 0.03), and total leukocyte count (−0.11 ± 0.01; P = 0.04). At 4 months after STEMI, LVEF was well preserved (54.1 ± 8.4 %) and was not associated with baseline LTL (P = 0.95). Baseline LTL was associated with n-terminal pro-brain natriuretic peptide (NT-proBNP) at 4 months (−0.14 ± 0.01; P = 0.02), albeit not independent for age and gender.

Conclusion

Our study does not support a role for LTL as a causal factor related to left ventricular ejection fraction after STEMI.

Diabetes, Endothelial Dysfunction, and Vascular Repair: What Should a Diabetologist Keep His Eye on?

Cardiovascular complications are the most common complications of diabetes mellitus. A prominent attribute of diabetic cardiovascular complications is accelerated atherosclerosis, considered as a still incurable disease, at least at more advanced stages. The discovery of endothelial progenitor cells (EPCs), able to replace old and injured mature endothelial cells and capable of differentiating into healthy and functional endothelial cells, has offered the prospect of merging the traditional theories on the pathogenesis of atherosclerosis with evolving concepts of vascular biology. The literature supports the notion that EPC alterations are involved in the pathogenesis of vascular diseases in diabetics, but at present many questions remain unanswered. In this review the aspects linking endothelial progenitor cells to the altered vascular biology in diabetes mellitus are discussed.

Investigating the role of acute mental stress on endothelial dysfunction: a systematic review and meta-analysis

Chronic stress is a known risk factor for both endothelial dysfunction and cardiovascular disease (CVD), but less is known of how acute mental stress affects the vasculature. In this systematic review and meta-analysis, we analyzed the impact of acute mental stress on flow-mediated dilation (FMD), an indicator of endothelial function. We searched the Medline, Cochrane, EMBASE, and ISI Web of Knowledge databases through May 2014, to identify publications in English-language journals. The primary outcome was the change in FMD from baseline to the time of measurement. We also assessed the risk of bias and the heterogeneity of included studies. Our search identified eight prospective studies, which displayed significant heterogeneity. Four studies measured FMD while the subject was performing the task; six measured FMD after the task had been completed. The total number of participants was 164. The pooled results indicate that FMD did not change significantly while the task was being performed (pooled difference in means: -0.853; 95 % confidence interval (CI), -3.926/2.220; P = 0.586); however, FMD measured after the task was completed was significantly less than baseline (pooled difference in means: -2.450; 95 %CI, -3.925/-0.975; P = 0.001). In conclusions, our findings provide evidence that an acute stressful experience has a delayed, negative impact on the function of the endothelium. Repeated exposure to short-term stress may lead to permanent injury of the vasculature. Therefore, assessment of patients' exposure to both repeated acute mental stress and chronic stress may be useful in determining their risk of developing CVD.

Vascular effects of exercise training in CKD: current evidence and pathophysiological mechanisms

Cardiovascular disease remains the main cause of morbidity and mortality in patients with CKD, an observation that cannot be explained by the coexistence of traditional risk factors alone. Recently, other mechanisms, such as alterations in nitric oxide bioavailability, impaired endothelial repair mechanisms, inflammation, and oxidative stress (all characteristic in CKD), have gained much attention as mediators for the increased cardiovascular risk. Regular physical training is a valuable nonpharmacological intervention for primary and secondary prevention of cardiovascular disease. Likewise, the benefits of exercise training on exercise capacity and quality of life are increasingly recognized in patients with CKD. Furthermore, exercise training could also influence potential reversible mechanisms involved in atherosclerosis and arteriosclerosis. After discussing briefly the general concepts of vascular disease in CKD, this review provides an overview of the current evidence for the effects of exercise training at both clinical and preclinical levels. It concludes with some practical considerations on exercise training in this specific patient group.

Characteristic of c-Kit+ progenitor cells in explanted human hearts

According to literature data, self-renewing, multipotent, and clonogenic cardiac c-Kit⁺ progenitor cells occur within human myocardium. The aim of this study was to isolate and characterize c-Kit⁺ progenitor cells from explanted human hearts. Experimental material was obtained from 19 adult and 7 pediatric patients. Successful isolation and culture was achieved for 95 samples (84.1 %) derived from five different regions of the heart: right and left ventricles, atrium, intraventricular septum, and apex. The average percentage of c-Kit⁺ cells, as assessed by FACS, ranged between 0.7 and 0.9 %. In contrast to published data we do not observed statistically significant differences in the number of c-Kit⁺ cells between disease-specific groups, parts of the heart or sexes. Nevertheless, c-Kit⁺ cells were present in significant numbers (11–24 %) in samples derived from three explanted pediatric hearts. c-Kit⁺ cells were also positive for CD105 and a majority of them was positive for CD31 and CD34 (83.7 ± 8.6 and 75.7 ± 11.4 %, respectively). Immunohistochemical analysis of the heart tissue revealed that most cells possessing the c-Kit antigen were also positive for tryptase, a specific mast cell marker. However, flow cytometry analysis has shown cultured c-Kit⁺ cells to be negative for hematopoietic marker CD45 and mast cell marker CD33. Isolated c-Kit⁺ cells display mesenchymal stem cell features and are thought to differentiate into endothelial cells.

Effects of physical activity on endothelial progenitor cells (EPCs)

Physical activity has a therapeutic role in cardiovascular disease (CVD), through its beneficial effects on endothelial function and cardiovascular system. Circulating endothelial progenitor cells (EPCs) are bone marrow (BM) derived cells that represent a novel therapeutic target in CVD patients, because of their ability to home to sites of ischemic injury and repair the damaged vessels. Several studies show that physical activity results in a significant increase in circulating EPCs, and, in particular, there are some evidence of the beneficial exercise-induced effects on EPCs activity in CVD settings, including coronary artery disease (CAD), heart failure (HF), and peripheral artery disease (PAD). The aim of this paper is to review the current evidence about the beneficial effects of physical exercise on endothelial function and EPCs levels and activity in both healthy subjects and patients with CVD.

Effects of exercise training on endothelial progenitor cells in cardiovascular disease: a systematic review

This review aimed to examine the effects of exercise training on mobilization of endothelial progenitor cells (EPCs) in patients with cardiovascular disease and to discuss the possible mechanisms involved in the process. A computer-aided search on PubMed and PEDro was conducted to identify relevant studies published up to June 2012. Two reviewers independently selected studies for inclusion and extracted data, namely, quantitative assessment of circulating EPCs. Of the 88 identified studies, 13 met the inclusion criteria. The 13 studies enrolled 648 participants, including patients with chronic heart failure, peripheral artery disease, and coronary artery disease. The exercise characteristics varied largely across the studies: exercise duration ranged from 2 wks to 6 mos, session duration ranged from 20 to 60 mins, and exercise intensity was usually calculated using the maximal heart rate (ranging from 75% to 85%) or the peak/maximum oxygen consumption (60%-70%). All studies used aerobic exercise. The great majority of the 13 studies reported significant effects of different exercise regimens on the number of circulating EPCs. In summary, exercise training seems to increase the number of circulating EPCs, which could contribute to vascular regeneration and angiogenesis. These positive effects of chronic exercise seem to be closely related to the bioavailability of nitric oxide, including increased activity of endothelial nitric oxide synthase and antioxidant enzymes, and activation of matrix metalloproteinase 9.

Circulating cells as predictors of secondary manifestations of cardiovascular disease: design of the CIRCULATING CELLS study

Biomarkers for primary or secondary risk prediction of cardiovascular disease (CVD) are urgently needed to improve individual treatment and clinical trial design. The vast majority of biomarker discovery studies has concentrated on plasma/serum as an easily accessible source. Although numerous markers have been identified, their added predictive value on top of traditional risk factors has been limited, as the biological specimen does not specifically reflect expression profiles related with CVD progression and because the signal is often diluted by marker release from other organs. In contrast to serum markers, circulating cells serve as indicators of the actual disease state due to their active role in the pathogenesis of CVD and are responsible for the majority of secreted biomarkers. Therefore, the CIRCULATING CELLS study was initiated, focusing on the cellular effectors of atherosclerosis in the circulation. In total, 714 patients with coronary artery disease (CAD) symptoms were included. Blood cell fractions (monocytes, T-lymphocytes, platelets, granulocytes, PBMC) of all individual patients were isolated and stored for analysis. Concomitantly, extensive flow cytometric characterization of these populations was performed. From each patient, a detailed clinical profile together with extensive questionnaires about medical history and life style was obtained. Various high-throughput -omics approaches (protein, mRNA, miRNA) are currently being undertaken. Data will be integrated with advanced bioinformatics for discovery and validation of secondary risk markers for adverse events. Overall, the CIRCULATING CELLS study grants the interesting possibility that it will both identify novel biomarkers and provide useful insights into the pathophysiology of CAD in patients.

Erectile dysfunction may be the first clinical sign of insulin resistance and endothelial dysfunction in young men

OBJECTIVES

The purpose of this study is to investigate the possible underlying pathogenesis of erectile dysfunction (ED) without well-known etiology in young men under the age of 40 years.

METHODS

192 patients and 33 normal controls were enrolled. ED was evaluated by using the International Index of Erectile Function-5 (IIEF-5) questionnaire. Traditional cardiovascular risk factors, hormone levels, and vascular parameters were measured. Insulin resistance (IR) was measured by homeostasis model assessment (HOMA).

RESULTS

Patients with ED had significantly higher levels of systolic blood pressure (SBP), high-sensitivity C-reactive protein (Hs-CRP), high Insulin resistance index (HOMA-IR) and carotid intima-media thickness (IMT), compared with controls. The brachial artery endothelium-dependent flow-mediated vasodilation (FMD) values were significantly lower in ED patients. By multivariate logistic regression analysis, FMD, SBP, Hs-CRP and HOMA-IR were significantly associated with ED. In receiver-operating characteristic (ROC) analysis, FMD was a significant predictor of ED (area under the curve (AUC) 0.933, p < 0.001). The cutoff value of FMD <10.4 % had sensitivity of 81.3 % and specificity of 100 %. HOMA-IR was also proven to be predictor of ED (AUC of HOMA-IR 0.759, p < 0.001).

CONCLUSIONS

ED may be the first clinical sign of endothelial dysfunction and a clinical marker of cardiovascular and metabolic diseases. Subclinical endothelial dysfunction and insulin resistance may be the underlying pathogenesis of ED in young patients without well-known etiology. Measurement of FMD, HOMA-IR can improve our ability to predict and treat ED, as well as subclinical cardiovascular disease early in young men.