Aerobic exercise training mitigates tumor growth and cancer-induced splenomegaly through modulation of non-platelet platelet factor 4 expression.

Exercise training reduces the incidence of several cancers, but the mechanisms underlying these effects are not fully understood. Exercise training can affect the spleen function, which controls the hematopoiesis and immune response. Analyzing different cancer models, we identified that 4T1, LLC, and CT26 tumor-bearing mice displayed enlarged spleen (splenomegaly), and exercise training reduced spleen mass toward control levels in two of these models (LLC and CT26). Exercise training also slowed tumor growth in melanoma B16F10, colon tumor 26 (CT26), and Lewis lung carcinoma (LLC) tumor-bearing mice, with minor effects in mammary carcinoma 4T1, MDA-MB-231, and MMTV-PyMT mice. In silico analyses using transcriptome profiles derived from these models revealed that platelet factor 4 (Pf4) is one of the main upregulated genes associated with splenomegaly during cancer progression. To understand whether exercise training would modulate the expression of these genes in the tumor and spleen, we investigated particularly the CT26 model, which displayed splenomegaly and had a clear response to the exercise training effects. RT-qPCR analysis confirmed that trained CT26 tumor-bearing mice had decreased Pf4 mRNA levels in both the tumor and spleen when compared to untrained CT26 tumor-bearing mice. Furthermore, exercise training specifically decreased Pf4 mRNA levels in the CT26 tumor cells. Aspirin treatment did not change tumor growth, splenomegaly, and tumor Pf4 mRNA levels, confirming that exercise decreased non-platelet Pf4 mRNA levels. Finally, tumor Pf4 mRNA levels are deregulated in The Cancer Genome Atlas Program (TCGA) samples and predict survival in multiple cancer types. This highlights the potential therapeutic value of exercise as a complementary approach to cancer treatment and underscores the importance of understanding the exercise-induced transcriptional changes in the spleen for the development of novel cancer therapies.

mt-Ty 5'tiRNA regulates skeletal muscle cell proliferation and differentiation.

In this study, we sought to determine the role of tRNA-derived fragments in the regulation of gene expression during skeletal muscle cell proliferation and differentiation. We employed cell culture to examine the function of mt-Ty 5' tiRNAs. Northern blotting, RT-PCR as well as RNA-Seq, were performed to determine the effects of mt-Ty 5' tiRNA loss and gain on gene expression. Standard and transmission electron microscopy (TEM) were used to characterize cell and sub-cellular structures. mt-Ty 5'tiRNAs were found to be enriched in mouse skeletal muscle, showing increased levels in later developmental stages. Gapmer-mediated inhibition of tiRNAs in skeletal muscle C2C12 myoblasts resulted in decreased cell proliferation and myogenic differentiation; consistent with this observation, RNA-Seq, transcriptome analyses, and RT-PCR revealed that skeletal muscle cell differentiation and cell proliferation pathways were also downregulated. Conversely, overexpression of mt-Ty 5'tiRNAs in C2C12 cells led to a reversal of these transcriptional trends. These data reveal that mt-Ty 5'tiRNAs are enriched in skeletal muscle and play an important role in myoblast proliferation and differentiation. Our study also highlights the potential for the development of tiRNAs as novel therapeutic targets for muscle-related diseases.

mTOR signaling-related microRNAs as cardiac hypertrophy modulators in high-volume endurance training.

Aerobic exercise training (ET) promotes cardiovascular adaptations, including physiological left ventricular hypertrophy (LVH). However, the molecular mechanisms underlying these changes are unclear. The study aimed to elucidate specific microRNAs (miRNAs) and target genes involved with the protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling in high-volume ET-induced LVH. Eight-week-old female Wistar rats were assigned to three groups: sedentary control (SC), trained protocol 1 (P1), and trained protocol 2 (P2). P1 consisted of 60 min/day of swimming, 5 times/wk, for 10 wk. P2 consisted of the same protocol as P1 until the 8th week; in the 9th week rats trained 2 times/day, and in the 10th week they trained 3 times/day. Subsequently, structure and molecular parameters were evaluated in the heart. Trained groups demonstrate higher values of peak oxygen uptake ([Formula: see text]), exercise tolerance, and LVH in a volume-dependent manner. The miRNA-26a-5p levels were higher in P1 and P2 compared with the SC group (150 ± 15%, d = 1.8; 148 ± 16%, d = 1.7; and 100 ± 7%, respectively; P < 0.05). In contrast, miRNA-16-5p levels were lower in P1 and P2 compared with the SC group (69 ± 5%, d = 2.3, P < 0.01; 37 ± 4%, d = 5.6, P < 0.001; and 100 ± 6%, respectively). Additionally, miRNA-16-5p knockdown and miRNA-26a-5p overexpression significantly promoted cardiomyocyte hypertrophy in neonatal rat cardiomyocytes. Both miRNAs were selected, with the DIANA Tools bioinformatics website, for acting in the mTOR signaling pathway. The protein expression of AKT, MTOR, ribosomal protein S6 kinase beta-1 (P70S6K), and eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) were greater in P1 and even more pronounced in P2. Nonetheless, glycogen synthase kinase 3 beta (GSK3ß) protein expression was lower in trained groups. Together, these molecular changes may contribute to a pronounced physiological LVH observed in high-volume aerobic training.NEW & NOTEWORTHY Physiological hypertrophic growth of the heart as a compensatory response to exercise training (ET) is coupled with recent progress in dissecting the microRNA (miRNA)-mediated molecular basis of hypertrophy. Aerobic ET seems to reduce miRNA-16-5p and increase miRNA-26a-5p expression in a volume-dependent mode, activating protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways, and likely produces an enhanced left ventricular hypertrophy (LVH) in high-volume endurance training. New insight into these mechanisms can be useful in understanding physiological LVH and how it might be harnessed as a therapeutic application.

Walking Training Increases microRNA-126 Expression and Muscle Capillarization in Patients with Peripheral Artery Disease.

Patients with peripheral artery disease (PAD) have reduced muscle capillary density. Walking training (WT) is recommended for PAD patients. The goal of the study was to verify whether WT promotes angiogenesis in PAD-affected muscle and to investigate the possible role of miRNA-126 and the vascular endothelium growth factor (VEGF) angiogenic pathways on this adaptation. Thirty-two men with PAD were randomly allocated to two groups: WT (n = 16, 2 sessions/week) and control (CO, n = 16). Maximal treadmill tests and gastrocnemius biopsies were performed at baseline and after 12 weeks. Histological and molecular analyses were performed by blinded researchers. Maximal walking capacity increased by 65% with WT. WT increased the gastrocnemius capillary-fiber ratio (WT = 109 ± 13 vs. 164 ± 21 and CO = 100 ± 8 vs. 106 ± 6%, p < 0.001). Muscular expression of miRNA-126 and VEGF increased with WT (WT = 101 ± 13 vs. 130 ± 5 and CO = 100 ± 14 vs. 77 ± 20%, p < 0.001; WT = 103 ± 28 vs. 153 ± 59 and CO = 100 ± 36 vs. 84 ± 41%, p = 0.001, respectively), while expression of PI3KR2 decreased (WT = 97 ± 23 vs. 75 ± 21 and CO = 100 ± 29 vs. 105 ± 39%, p = 0.021). WT promoted angiogenesis in the muscle affected by PAD, and miRNA-126 may have a role in this adaptation by inhibiting PI3KR2, enabling the progression of the VEGF signaling pathway.

Physiological Responses to Maximal and Submaximal Walking in Patients with Symptomatic Peripheral Artery Disease. / Respostas Fisiológicas à Caminhada Máxima e Submáxima em Pacientes com Doença Arterial Periférica Sintomática.

BACKGROUND: Although maximal and submaximal walking are recommended for patients with peripheral artery disease (PAD), performing these exercises may induce different physiological responses. OBJECTIVES: To compare the acute effects of maximal and submaximal walking on post-exercise cardiovascular function, regulation, and associated pathophysiological processes in patients with symptomatic PAD. METHODS: Thirty male patients underwent 2 sessions: maximal walking (Gardner's protocol) and submaximal walking (15 bouts of 2 minutes of walking separated by 2 minutes of upright rest). In each session, blood pressure (BP), heart rate (HR), cardiac autonomic modulation (HR variability), forearm and calf blood flows (BF), vasodilatory capacity (reactive hyperemia), nitric oxide (NO), oxidative stress (lipid peroxidation), and inflammation (four markers) were measured pre- and post-walking. ANOVAs were employed, and p < 0.05 was considered significant. RESULTS: Systolic and mean BP decreased after the submaximal session, but they increased after the maximal session (interactions, p < 0.001 for both). Diastolic BP did not change after the submaximal session (p > 0.05), and it increased after maximal walking (interaction, p < 0.001). HR, sympathovagal balance, and BF increased similarly after both sessions (moment, p < 0.001, p = 0.04, and p < 0.001, respectively), while vasodilatory capacity, NO, and oxidative stress remained unchanged (p > 0.05). Vascular and intercellular adhesion molecules increased similarly after both maximal and submaximal walking sessions (moment, p = 0.001). CONCLUSIONS: In patients with symptomatic PAD, submaximal, but not maximal walking reduced post-exercise BP, while maximal walking maintained elevated cardiac overload during the recovery period. On the other hand, maximal and submaximal walking sessions similarly increased post-exercise HR, cardiac sympathovagal balance, and inflammation, while they did not change post-exercise NO bioavailability and oxidative stress.

FUNDAMENTO: Embora a caminhada máxima e submáxima sejam recomendadas para pacientes com doença arterial periférica (DAP), a realização desses exercícios pode induzir diferentes respostas fisiológicas. OBJETIVOS: Comparar os efeitos agudos de caminhada máxima e submáxima na função cardiovascular, a regulação e os processos fisiopatológicos associados pós-exercício em pacientes com DAP sintomática. MÉTODOS: Trinta pacientes do sexo masculino foram submetidos a 2 sessões: caminhada máxima (protocolo de Gardner) e caminhada submáxima (15 períodos de 2 minutos de caminhada separados por 2 minutos de repouso ereto). Em cada sessão, foram medidos a pressão arterial (PA), a frequência cardíaca (FC), a modulação autonômica cardíaca (variabilidade da FC), os fluxos sanguíneos (FS) do antebraço e da panturrilha, a capacidade vasodilatadora (hiperemia reativa), o óxido nítrico (ON), o estresse oxidativo (a peroxidação lipídica) e a inflamação (quatro marcadores), pré e pós-caminhada. ANOVAs foram empregadas e p < 0,05 foi considerado significativo. RESULTADOS: A PA sistólica e a PA média diminuíram após a sessão submáxima, mas aumentaram após a sessão máxima (interações, p < 0,001 para ambas). A PA diastólica não foi alterada após a sessão submáxima (p > 0,05), mas aumentou após a caminhada máxima (interação, p < 0,001). A FC, o equilíbrio simpatovagal e os FS aumentaram de forma semelhante após as duas sessões (momento, p < 0,001, p = 0,04 e p < 0,001, respectivamente), enquanto a capacidade vasodilatadora, o ON e o estresse oxidativo permaneceram inalterados (p > 0,05). As moléculas de adesão vascular e intercelular aumentaram de forma semelhante após as sessões de caminhada máxima e submáxima (momento, p = 0,001). CONCLUSÕES: Nos pacientes com a DAP sintomática, a caminhada submáxima, mas não a máxima, reduziu a PA pós-exercício, enquanto a caminhada máxima manteve a sobrecarga cardíaca elevada durante o período de recuperação. Por outro lado, as sessões de caminhada máxima e submáxima aumentaram a FC, o equilíbrio simpatovagal cardíaco e a inflamação pós-exercício de forma semelhante, enquanto não alteraram a biodisponibilidade de ON e o estresse oxidativo pós-exercício.

Respostas fisiológicas à caminhada máxima e submáxima em pacientes com doença arterial periférica sintomática / Physiological responses to maximal and submaximal walking in patients with symptomatic peripheral artery disease

Resumo Fundamento: Embora a caminhada máxima e submáxima sejam recomendadas para pacientes com doença arterial periférica (DAP), a realização desses exercícios pode induzir diferentes respostas fisiológicas. Objetivos: Comparar os efeitos agudos de caminhada máxima e submáxima na função cardiovascular, a regulação e os processos fisiopatológicos associados pós-exercício em pacientes com DAP sintomática. Métodos: Trinta pacientes do sexo masculino foram submetidos a 2 sessões: caminhada máxima (protocolo de Gardner) e caminhada submáxima (15 períodos de 2 minutos de caminhada separados por 2 minutos de repouso ereto). Em cada sessão, foram medidos a pressão arterial (PA), a frequência cardíaca (FC), a modulação autonômica cardíaca (variabilidade da FC), os fluxos sanguíneos (FS) do antebraço e da panturrilha, a capacidade vasodilatadora (hiperemia reativa), o óxido nítrico (ON), o estresse oxidativo (a peroxidação lipídica) e a inflamação (quatro marcadores), pré e pós-caminhada. ANOVAs foram empregadas e p < 0,05 foi considerado significativo. Resultados: A PA sistólica e a PA média diminuíram após a sessão submáxima, mas aumentaram após a sessão máxima (interações, p < 0,001 para ambas). A PA diastólica não foi alterada após a sessão submáxima (p > 0,05), mas aumentou após a caminhada máxima (interação, p < 0,001). A FC, o equilíbrio simpatovagal e os FS aumentaram de forma semelhante após as duas sessões (momento, p < 0,001, p = 0,04 e p < 0,001, respectivamente), enquanto a capacidade vasodilatadora, o ON e o estresse oxidativo permaneceram inalterados (p > 0,05). As moléculas de adesão vascular e intercelular aumentaram de forma semelhante após as sessões de caminhada máxima e submáxima (momento, p = 0,001). Conclusões: Nos pacientes com a DAP sintomática, a caminhada submáxima, mas não a máxima, reduziu a PA pós-exercício, enquanto a caminhada máxima manteve a sobrecarga cardíaca elevada durante o período de recuperação. Por outro lado, as sessões de caminhada máxima e submáxima aumentaram a FC, o equilíbrio simpatovagal cardíaco e a inflamação pós-exercício de forma semelhante, enquanto não alteraram a biodisponibilidade de ON e o estresse oxidativo pós-exercício.

Abstract Background: Although maximal and submaximal walking are recommended for patients with peripheral artery disease (PAD), performing these exercises may induce different physiological responses. Objectives: To compare the acute effects of maximal and submaximal walking on post-exercise cardiovascular function, regulation, and associated pathophysiological processes in patients with symptomatic PAD. Methods: Thirty male patients underwent 2 sessions: maximal walking (Gardner's protocol) and submaximal walking (15 bouts of 2 minutes of walking separated by 2 minutes of upright rest). In each session, blood pressure (BP), heart rate (HR), cardiac autonomic modulation (HR variability), forearm and calf blood flows (BF), vasodilatory capacity (reactive hyperemia), nitric oxide (NO), oxidative stress (lipid peroxidation), and inflammation (four markers) were measured pre- and post-walking. ANOVAs were employed, and p < 0.05 was considered significant. Results: Systolic and mean BP decreased after the submaximal session, but they increased after the maximal session (interactions, p < 0.001 for both). Diastolic BP did not change after the submaximal session (p > 0.05), and it increased after maximal walking (interaction, p < 0.001). HR, sympathovagal balance, and BF increased similarly after both sessions (moment, p < 0.001, p = 0.04, and p < 0.001, respectively), while vasodilatory capacity, NO, and oxidative stress remained unchanged (p > 0.05). Vascular and intercellular adhesion molecules increased similarly after both maximal and submaximal walking sessions (moment, p = 0.001). Conclusions: In patients with symptomatic PAD, submaximal, but not maximal walking reduced post-exercise BP, while maximal walking maintained elevated cardiac overload during the recovery period. On the other hand, maximal and submaximal walking sessions similarly increased post-exercise HR, cardiac sympathovagal balance, and inflammation, while they did not change post-exercise NO bioavailability and oxidative stress.

Exercise Training Preserves Myocardial Strain and Improves Exercise Tolerance in Doxorubicin-Induced Cardiotoxicity.

Doxorubicin causes cardiotoxicity and exercise intolerance. Pre-conditioning exercise training seems to prevent doxorubicin-induced cardiac damage. However, the effectiveness of the cardioprotective effects of exercise training concomitantly with doxorubicin treatment remains largely unknown. To determine whether low-to-moderate intensity aerobic exercise training during doxorubicin treatment would prevent cardiotoxicity and exercise intolerance, we performed exercise training concomitantly with chronic doxorubicin treatment in mice. Ventricular structure and function were accessed by echocardiography, exercise tolerance by maximal exercise test, and cardiac biology by histological and molecular techniques. Doxorubicin-induced cardiotoxicity, evidenced by impaired ventricular function, cardiac atrophy, and fibrosis. Exercise training did not preserve left ventricular ejection fraction or reduced fibrosis. However, exercise training preserved myocardial circumferential strain alleviated cardiac atrophy and restored cardiomyocyte cross-sectional area. On the other hand, exercise training exacerbated doxorubicin-induced body wasting without affecting survival. Finally, exercise training blunted doxorubicin-induced exercise intolerance. Exercise training performed during doxorubicin-based chemotherapy can be a valuable approach to attenuate cardiotoxicity.

Walking Training Improves Systemic and Local Pathophysiological Processes in Intermittent Claudication.

OBJECTIVE: This study examined the impact of submaximal walking training (WT) on local and systemic nitric oxide (NO) bioavailability, inflammation, and oxidative stress in patients with intermittent claudication (IC). METHODS: The study employed a randomised, controlled, parallel group design and was performed in a single centre. Thirty-two men with IC were randomly allocated to two groups: WT (n = 16, two sessions/week, 15 cycles of two minutes walking at an intensity corresponding to the heart rate obtained at the pain threshold interspersed by two minutes of upright rest) and control (CO, n = 16, two sessions/week, 30 minutes of stretching). NO bioavailability (blood NO and muscle nitric oxide synthase [eNOS]), redox homeostasis (catalase [CAT], superoxide dismutase [SOD], lipid peroxidation [LPO] measured in blood and muscle), and inflammation (interleukin-6 [IL-6], C-reactive protein [CRP], tumour necrosis factor α [TNF-α], intercellular adhesion molecules [ICAM], vascular adhesion molecules [VCAM] measured in blood and muscle) were assessed at baseline and after 12 weeks. RESULTS: WT statistically significantly increased blood NO, muscle eNOS, blood SOD and CAT, and muscle SOD and abolished the increase in circulating and muscle LPO observed in the CO group. WT decreased blood CRP, ICAM, and VCAM and muscle IL-6 and CRP and eliminated the increase in blood TNF-α and muscle TNF-α, ICAM and VCAM observed in the CO group. CONCLUSION: WT at an intensity of pain threshold improved NO bioavailability and decreased systemic and local oxidative stress and inflammation in patients with IC. The proposed WT protocol provides physiological adaptations that may contribute to cardiovascular health in these patients.

Breast Cancer Promotes Cardiac Dysfunction Through Deregulation of Cardiomyocyte Ca2+-Handling Protein Expression That is Not Reversed by Exercise Training.

Background Patients treated for breast cancer have a high incidence of cardiovascular complications. In this study, we evaluated the impact of breast cancer on cardiac function and cardiomyocyte Ca2+-handling protein expression. We also investigated whether exercise training (ET) would prevent these potential alterations. Methods and Results Transgenic mice with spontaneous breast cancer (mouse mammary tumor virus-polyomavirus middle T antigen [MMTV-PyMT+], n=15) and littermate mice with no cancer (MMTV-PyMT-, n=14) were studied. For the ET analysis, MMTV-PyMT+ were divided into sedentary (n=10) and exercise-trained (n=12) groups. Cardiac function was evaluated by echocardiography with speckle-tracking imaging. Exercise tolerance test was conducted on a treadmill. Both studies were performed when the tumor became palpable and when it reached 1 cm3. After euthanasia, Ca2+-handling protein expression (Western blot) was evaluated. Exercise capacity was reduced in MMTV-PyMT+ compared with MMTV-PyMT- (Pinteraction=0.031). Longitudinal strain (Pgroup <0.001) and strain rate (Pgroup=0.030) were impaired. Cardiomyocyte phospholamban was increased (P=0.011), whereas phospho-phospholamban and sodium/calcium exchanger were decreased (P=0.038 and P=0.017, respectively) in MMTV-PyMT+. No significant difference in sarcoplasmic or endoplasmic reticulum calcium 2 ATPase (SERCA2a) was found. SERCA2a/phospholamban ratio was reduced (P=0.007). ET was not associated with increased exercise capacity. ET decreased left ventricular end-systolic diameter (Pgroup=0.038) and end-diastolic volume (Pgroup=0.026). Other morphological and functional cardiac parameters were not improved by ET in MMTV-PyMT+. ET did not improve cardiomyocyte Ca2+-handling protein expression. Conclusions Breast cancer is associated with decreased exercise capacity and subclinical left ventricular dysfunction in MMTV-PyMT+, which is at least partly associated with dysregulation of cardiomyocyte Ca2+ handling. ET did not prevent or reverse these changes.

Enalapril and treadmill running reduce adiposity, but only the latter causes adipose tissue browning in mice.

This study investigated whether regulation of the renin-angiotensin system (RAS) by enalapril and/or aerobic exercise training (AET) causes browning of the subcutaneous white adipose tissue (sWAT). C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At Week 8, HF-fed animals were divided into sedentary (HF), enalapril (HF-E), AET (HF-T), and enalapril plus AET (HF-ET) groups. Subsequently, sWAT was extracted for morphometry, determination of RAS expression, and biomarkers of WAT browning. The HF group displayed adipocyte hypertrophy and induction of the classical RAS axis. Conversely, all interventions reduced adiposity and induced the counterregulatory RAS axis. However, only AET raised plasma irisin, increased peroxisome proliferator-activated receptor-γ coactivator-1α, and uncoupling protein-1 levels, and the expression of PR-domain containing 16 in sWAT. Therefore, we concluded that AET-induced sWAT browning was independent of the counterregulatory axis shifting of RAS in HF diet-induced obesity.

Local and Systemic Inflammation and Oxidative Stress After a Single Bout of Maximal Walking in Patients With Symptomatic Peripheral Artery Disease.

OBJECTIVE: The aim of this study was to assess the effects of a single bout of maximal walking on blood and muscle nitric oxide (NO) bioavailability, oxidative stress, and inflammation in symptomatic peripheral artery disease (PAD) patients. METHODS: A total of 35 men with symptomatic PAD performed a graded maximal exercise test on a treadmill (3.2 km/h, 2% increase in grade every 2 minutes). Plasma samples and gastrocnemius muscle biopsies were collected preexercise and postexercise for assessment of NO bioavailability (plasma NO and muscle, endothelial NO synthase), oxidative stress and antioxidant function (lipid peroxidation [LPO], catalase [CAT], and superoxide dismutase), and inflammation (interleukin-6, C-reactive protein, tumor necrosis factor-α, intercellular adhesion molecules, and vascular adhesion molecules). The effects of the walking exercise were assessed using paired t tests or Wilcoxon tests. RESULTS: After maximal walking, plasma NO and LPO were unchanged (P > .05), plasma CAT decreased, and all blood inflammatory markers increased (all P ≤ .05). In the disease-affected skeletal muscle, endothelial NO synthase, CAT, LPO, and all inflammatory markers increased, whereas superoxide dismutase decreased (all P ≤ .05). CONCLUSION: In patients with symptomatic PAD, maximal exercise induces local and systemic impairments, which may play a key role in atherogenesis. Exercise strategies that avoid maximal effort may be important to reduce local and systemic damage and enhance clinical benefits.

Molecular Pathways Involved in Aerobic Exercise Training Enhance Vascular Relaxation.

PURPOSE: The beneficial effects of exercise training on the cardiovascular system are well known. Because our knowledge of exercise-induced vascular function is still limited, we aimed to uncover the molecular mechanisms conditioning the improved vascular relaxation in muscular arteries. METHODS: Male Wistar-Kyoto rats with the same ability to run on a treadmill after maximal exercise tests were allocated to the following two groups: trained (Tr) (treadmill, 50%-60% of maximal capacity, 5 d·wk) and untrained (UnTr). After 13 wk, the femoral arteries were harvested and used for functional, structural, and molecular analyses. RESULTS: Acetylcholine (ACh)-induced relaxation and nitric oxide (NO) production were enhanced in arteries from Tr rats compared with UnTr rats. Tr arteries exhibited reduced microRNA (miRNA)-124a expression (whose target is caveolin-1), increased the density of caveolae aligned along the sarcolemma and reduced ACh-induced relaxation in the presence of methyl-ß-cyclodextrin, which disrupts caveolae. Higher endothelial NO synthase (eNOS) expression with lower miRNA-155 expression and the posttranslational modification of eNOS (phosphorylation of stimulatory Ser1177 and dephosphorylation of inhibitory Thr495) by the PI3-kinase/Akt1/2/3 pathway also contributed to the higher NO production induced by exercise training. Furthermore, increased Cu/Zn- and extracellular-superoxide dismutase expression and enhanced effects of their pharmacological scavenger activity on the ACh-induced response were observed in Tr arteries. CONCLUSIONS: The results of the present study provide a molecular basis for exercise-induced NO bioavailability in healthy femoral arteries. Increased caveolae domain and eNOS expression/activity in Tr arteries are associated with downregulation of miRNA-124a and -155, as well as are involved with higher antioxidant defense, subsequently inducing a favorable endothelium-dependent milieu in Tr arteries.

Severe obstructive sleep apnea is associated with circulating microRNAs related to heart failure, myocardial ischemia, and cancer proliferation.

PURPOSE: Obstructive sleep apnea (OSA) is associated with multiple comorbid conditions including cardiovascular diseases and cancer. There is a growing interest in exploring biomarkers to understand the related mechanisms and improve the risk stratification of OSA. Circulating microRNAs (miRNAs) are single noncoding strands of nearly 22 nucleotides that posttranscriptionally regulate target gene expression. Our aim was to identify miRNA profiles associated with OSA. METHODS: We studied 48 male subjects, mostly Caucasian (63%) and overweight, divided by polysomnography into the no OSA control group (n = 6), mild OSA group (n = 12), moderate OSA group (n = 15), and severe OSA group (n = 15). The study groups were matched for age, body mass index (BMI), and body fat composition. miRNA profiles were measured from peripheral whole blood using two steps: (1) microarray analysis comprising more than 2500 miRNAs in a subsample of 12 subjects (three from each group); and (2) validation phase using real-time quantitative polymerase chain reaction (RTqPCR). RESULTS: The microarray assessment identified 21 differentially expressed miRNAs among the groups. The RT-qPCR assessment showed that miR-1254 and miR-320e presented a gradual increase in expression parallel to OSA severity. Linear regression analysis showed that severe OSA was independently associated with miR-1254 (ß = 68.4; EP = 29.8; p = 0.02) and miR-320e (ß = 76.1; EP = 31.3; p = 0.02). CONCLUSION: Severe OSA is independently associated with miRNAs that are involved in heart failure (miR-1254), myocardial ischemia/reperfusion (miR-320e), and cell proliferation in some cancer types (miR-1254 and miR-320e). Future investigations addressing whether these miRs may provide prognostic information in OSA are needed.

Effects of aerobic and inspiratory training on skeletal muscle microRNA-1 and downstream-associated pathways in patients with heart failure.

BACKGROUND: The exercise intolerance in chronic heart failure with reduced ejection fraction (HFrEF) is mostly attributed to alterations in skeletal muscle. However, the mechanisms underlying the skeletal myopathy in patients with HFrEF are not completely understood. We hypothesized that (i) aerobic exercise training (AET) and inspiratory muscle training (IMT) would change skeletal muscle microRNA-1 expression and downstream-associated pathways in patients with HFrEF and (ii) AET and IMT would increase leg blood flow (LBF), functional capacity, and quality of life in these patients. METHODS: Patients age 35 to 70 years, left ventricular ejection fraction (LVEF) ≤40%, New York Heart Association functional classes II-III, were randomized into control, IMT, and AET groups. Skeletal muscle changes were examined by vastus lateralis biopsy. LBF was measured by venous occlusion plethysmography, functional capacity by cardiopulmonary exercise test, and quality of life by Minnesota Living with Heart Failure Questionnaire. All patients were evaluated at baseline and after 4 months. RESULTS: Thirty-three patients finished the study protocol: control (n = 10; LVEF = 25 ± 1%; six males), IMT (n = 11; LVEF = 31 ± 2%; three males), and AET (n = 12; LVEF = 26 ± 2%; seven males). AET, but not IMT, increased the expression of microRNA-1 (P = 0.02; percent changes = 53 ± 17%), decreased the expression of PTEN (P = 0.003; percent changes = -15 ± 0.03%), and tended to increase the p-AKTser473 /AKT ratio (P = 0.06). In addition, AET decreased HDAC4 expression (P = 0.03; percent changes = -40 ± 19%) and upregulated follistatin (P = 0.01; percent changes = 174 ± 58%), MEF2C (P = 0.05; percent changes = 34 ± 15%), and MyoD expression (P = 0.05; percent changes = 47 ± 18%). AET also increased muscle cross-sectional area (P = 0.01). AET and IMT increased LBF, functional capacity, and quality of life. Further analyses showed a significant correlation between percent changes in microRNA-1 and percent changes in follistatin mRNA (P = 0.001, rho = 0.58) and between percent changes in follistatin mRNA and percent changes in peak VO2 (P = 0.004, rho = 0.51). CONCLUSIONS: AET upregulates microRNA-1 levels and decreases the protein expression of PTEN, which reduces the inhibitory action on the PI3K-AKT pathway that regulates the skeletal muscle tropism. The increased levels of microRNA-1 also decreased HDAC4 and increased MEF2c, MyoD, and follistatin expression, improving skeletal muscle regeneration. These changes associated with the increase in muscle cross-sectional area and LBF contribute to the attenuation in skeletal myopathy, and the improvement in functional capacity and quality of life in patients with HFrEF. IMT caused no changes in microRNA-1 and in the downstream-associated pathway. The increased functional capacity provoked by IMT seems to be associated with amelioration in the respiratory function instead of changes in skeletal muscle. ClinicalTrials.gov (Identifier: NCT01747395).

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 (ηp2 = 0.489), cardiorespiratory fitness (ηp2 = 0.463), and MMP-9 (ηp2 = 0.582). Birth weight or the PA program produced significant independent effects on systolic blood pressure (birth weight: ηp2 = 0.431; PA program: ηp2 = 0.615) and EPC colony forming units (birth weight: ηp2 = 0.541; PA program: ηp2 = 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 (ηp2 = 0.123), NO (ηp2 = 0.258), and VEGF-A (ηp2 = 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.

Effects of exercise training and stem cell therapy on the left ventricle of infarcted rats.

INTRODUCTION AND OBJECTIVES: Stem cell therapy and aerobic exercise are non-pharmacological therapies following myocardial infarction. The aim of this study was to test whether aerobic exercise training enhances the benefits of mesenchymal stem cell (MSC) therapy on remodeling of the extracellular matrix and fetal gene expression in the left ventricle of infarcted rats. METHODS: Myocardial infarction was surgically induced in six-week old male Wistar rats. Animals were divided into four groups: sedentary control (SC) and sedentary and stem cell treated (SCMSC); exercised (EX) and exercised and stem cell treated (EXMSC). Bone marrow-derived MSCs were immediately transplanted via the tail vein (concentration: 1×106 cells). Exercise training (five days/week, 60 min/day; 60% of maximal running speed) started 24 hours after myocardial infarction and lasted for 12 weeks. RESULTS: Exercise capacity was higher in exercised than in sedentary groups. Animals in the SCMSC, EX and EXMSC groups exhibited better cardiac function than those in SC. Collagen content was lower in the SCMSC, EX and EXMSC groups than in SC and skeletal α-actin expression was lower in EX and EXMSC than in SC. The α/ß-MHC ratio was higher in EX and EXMSC than in SC. The combination of therapies further reduced collagen content in the remote region of the infarct (∼24%) and skeletal α-actin expression (∼30%). CONCLUSION: Aerobic exercise training appears to enhance the beneficial effects of stem cell therapy on remodeling of the extracellular matrix and fetal gene expression in the left ventricle of rats with moderate infarction.

Aerobic Training in Young Men Increases the Transfer of Cholesterol to High Density Lipoprotein In Vitro: Impact of High Density Lipoprotein Size.

Exercise training not only improves the plasma lipid profile but also reduces risk of developing coronary heart disease. We investigate whether plasma lipids and high density lipoprotein (HDL) metabolism are affected by aerobic training and whether the high-density lipoprotein cholesterol (HDL-C) levels at baseline influence exercise-induced changes in HDL. Seventy-one male sedentary volunteers were evaluated and allocated in two subgroups, according to the HLD-C levels (< or >40 mg/dL). Participants underwent an 18-week aerobic training period. Blood was sampled before and after training for biochemical analysis. Plasma lipids, apolipoproteins, HDL diameter, and VO2 peak were determined. Lipid transfers to HDL were determined in vitro by incubating plasma samples with a donor lipid artificial nanoemulsion. After the 18-week period of aerobic training, the VO2 peak increased, while the mean body mass index (BMI) decreased. HDL-C concentration was higher after the training period, but low-density lipoprotein cholesterol (LDL-C) and non-HDL-C did not change. The transfer of esterified cholesterol and phospholipids was greater after exercise training, but the triacylglycerol and unesterified cholesterol transfers were unchanged. The HDL particle diameter increased after aerobic training in all participants. When the participants were separated in low-HDL and normal-HDL groups, the postaerobic exercise increment in HDL-C was higher in the low-HDL group, while the transfer of esterified cholesterol was lower. In conclusion, aerobic exercise training increases the lipid transfers to HDL, as measured by an in vitro method, which possibly contributes to the classical elevation of the HDL-C associated with training.

Blockade of AT1 receptor restore the migration of vascular smooth muscle cells in high sodium medium.

The present study aimed to test the hypothesis that increased sodium concentration affects the migratory phenotype of vascular smooth muscle cells (VSMCs) independently of the haemodynamic factors. Cell migration was evaluated by wound-healing assay under the following conditions: high sodium (HS, 160 mM) and control (CT, 140 mM). Cell viability was assessed by annexin V and propidium iodide labeling. Cyclooxygenase-2 (COX-2) gene expression was analysed by reverse transcription polymerase chain reaction. ERK1/2 phosphorylation was assessed by western blot. Exposure of VSMCs to HS reduced migration, and AT1R blockade prevented this response. HS increased COX-2 gene expression, and COX-2 blockade prevented the reduction in VSMC migration induced by HS. HS also increased ERK1/2 phosphorylation, and ERK1/2 inhibition recovered VSMC migration as well as blocked COX-2 gene expression. The TXA2 receptor blocker, but not the prostacyclin receptor blocker, prevented the HS-induced VSMCs migration decrease. HS reduces the migration of VSMCs by increasing COX-2 gene expression via AT1R-ERK1/2 phosphorylation. In addition, increased COX-2 by HS seems to modulate the reduction of VSMCs migration by the TXA2 receptor.

ACE Gene Plays a Key Role in Reducing Blood Pressure in The Hyperintensive Elderly After Resistance Training.

Montrezol, FT, Marinho, R, Mota, GdFAd, D'almeida, V, de Oliveira, EM, Gomes, RJ, and Medeiros, A. ACE gene plays a key role in reducing blood pressure in the hyperintensive elderly after resistance training. J Strength Cond Res 33(4): 1119-1129, 2019-Hypertension is a difficult disease to control and exercise training plays a key role in hypertension control. Some individuals are not responsive to exercise training; so, we highlight the polymorphism of I allele of angiotensin-converting enzyme (ACE) as a factor responsible for this lack of responsiveness. The aim of this study was to evaluate the influence of ACE insertion/deletion genotypes on effects of resistance training on blood pressure (BP) and chronic inflammation. Eighty-six hypertensive volunteers, aged between 60 and 80, were evaluated. They performed 16 weeks of resistance training at 50% of 1 maximal repetition. The greatest benefits were seen on homozygous of the Insertion allele, whom presented reduction of systolic blood pressure (SBP: 129.31 ± 13.34 vs. 122.56 ± 9.68 mm Hg, p < 0.001) and diastolic blood pressure (DBP: 79.18 ± 8.05 vs. 70.12 ± 7.71 mm Hg, p < 0.01) during daytime period, and in 24-hour period (SBP: 127.12 ± 13.65 vs. 121.06± 9.68 mm Hg, p < 0.001 and DBP: 71.87 ± 8.39 vs. 68.75 ± 8.72 mm Hg, p < 0.05) and also increased circulating adiponectin levels (4.04 ± 1.79 vs. 6.00 ± 2.81 ng·ml, p < 0.01). Other genotypes showed no changes in BP and biochemical parameters. Our results suggest a cardio protective factor of I allele because only those homozygous showed reductions in BP and increases in adiponectin.

Corrigendum to "Exercise Training Restores Cardiac MicroRNA-1 and MicroRNA-29c to Nonpathological Levels in Obese Rats".

[This corrects the article DOI: 10.1155/2017/1549014.].