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Simple Summary: The regulation of oxidative stress at rest and in response to a single session of exercise is vital for cardiovascular and metabolic health. However, the lack of regular physical activity and exercise and the presence of obesity are known to negatively impact oxidative stress under both conditions. In the present study, the oxidative stress response in circulation and within exosome-like extracellular vesicles (ELVs) released by contracting skeletal muscle during exercise was examined following maximal intensity treadmill running. As a result, we demonstrate that aerobically untrained individuals with obesity exhibit an altered oxidative stress response to maximal treadmill running compared to aerobically untrained and aerobically trained individuals without obesity. Similarly, body mass index, an index of obesity, but not cardiorespiratory fitness, was associated with an adverse oxidative response at rest and immediately following maximal treadmill running. These findings suggest that obesity, more than improved cardiorespiratory fitness, differentially regulates plasma and circulating ELV indices of oxidative stress prior to and immediately following acute maximal treadmill exercise. The impact of cardiorespiratory fitness (VO2max) and obesity on indices of oxidative stress in plasma and circulating exosome-like extracellular vesicles (ELVs) were examined following acute exercise. Indices of oxidative stress in plasma and isolated plasma ELVs were examined in aerobically trained (NW-Tr; n = 15) and untrained (NW-UTr; n = 18) normal-weight individuals and aerobically untrained individuals with obesity (Ob-Utr; n = 10) prior to and immediately following acute maximal treadmill running. Following exercise, ELV flotillin-1 expression (p = 0.008) and plasma total antioxidant capacity (TAC; p = 0.010) increased more in NW-UTr compared to NW-Tr and Ob-UTr participants, whereas plasma protein carbonyls (PC) decreased more in Ob-UTr compared to NW-Tr and NW-UTr groups. ELV glutathione (GSH) concentrations decreased more in NW-Tr compared to NW-UTr and Ob-UTr participants (p = 0.009), whereas lipid peroxidase (LPO) concentrations increased more in Ob-UTr compared to NW-Tr and NW-UTr participants (p = 0.003). Body mass index (BMI) was associated negatively with plasma TAC and PC (p < 0.05) and positively with ELV LPO concentration responses (p = 0.009). Finally, plasma-to-total (plasma + ELV) GSH ratios decreased in Ob-UTr compared to NW-Tr and NW-UTr participants (p = 0.006), PC ratios increased in NW-Tr and NW-UTr compared to Ob-UTr subjects (p = 0.008), and reactive oxygen/nitrogen species ratios increased in NW-UTr and decreased in Ob-UTr participants (p < 0.001). BMI, independently of VO2max, differentially regulates indices of oxidative stress within plasma and circulating ELVs prior to and immediately following acute maximal treadmill exercise. [ABSTRACT FROM AUTHOR]

Pentraxin 3 (PTX3), a cardioprotective protein, has recently been shown to be associated with improved insulin resistance (IR) and glucose metabolism. Therefore, the primary purpose of this study was to examine whether or not increased plasma PTX3 following maximal aerobic exercise would differ between obese and normal-mass subjects, and its association with the homeostatic model assessment of insulin resistance (HOMA-IR) and glucose response. Twenty-five untrained obese (n = 13 [6 males and 7 females]) and normal-mass (n = 12 [5 males and 7 females]) subjects performed an acute bout of maximal aerobic exercise to assess maximal oxygen consumption ([VO.sub.2max]). At baseline, plasma PTX3 concentrations are decreased in obese compared with normal-mass subjects and are negatively associated with plasma insulin and HOMA-IR values. In response to maximal exercise, plasma PTX3 responses were similar in obese and normal-mass subjects while the intensity of plasma PTX3 response as indicated by area under the curve analysis (AUCi) was not associated with HOMA-IR or glucose AUCi. However, PTX3 AUCi was positively associated with cardiorespiratory fitness levels (relative [VO.sub.2max]). These findings suggest that PTX3 could serve as a biomarker for both metabolic health, as well as a measurement to monitor the effectiveness of exercise interventions in obesity. Key words: pentraxin 3, obesity, aerobic exercise, insulin resistance, cardiorespiratory fitness. On a montre recemment que la pentraxine 3 (PTX3), une proteine dotee de proprietes de cardioprotection, est associee a des ameliorations sur le plan de la resistance a l'insuline (IR) et du metabolisme du glucose. Par consequent, le principal objectif des presents travaux etait d'evaluer si l'augmentation des taux plasmatiques de PTX3 apres un effort physique aerobie maximal serait differente chez les sujets obeses comparativement aux sujets dont le poids est normal, et si cette observation serait associee a des modifications sur le plan de l'homeostasie de la resistance a l'insuline (ou HOMA-IR pour << homeostatic model assessment of insulin resistance >>) et de la reponse glycemique. Pour ce faire, 25 sujets non entraines obeses (n = 13 [6 hommes et 7 femmes]) et de poids normal (n = 12 [5 hommes et 7 femmes]) ont effectue un effort physique aerobie maximal intense en vue d'evaluer la consommation maximale d'oxygene ([VO.sub.2max]). Au debut de l'etude, les concentrations plasmatiques de PTX3 etaient plus basses chez les sujets obeses que chez les sujets de poids normal et inversement proportionnelles aux taux d'insuline plasmatique et aux valeurs de l'HOMA-IR. En reponse a l'effort physique maximal, les taux plasmatiques de PTX3 observes etaient semblables dans les 2 groupes, et l'aire sous la courbe << en ce qu'elle concerne l'augmentation des taux >> (ASCa) n'etait pas associee a l'ASCa des valeurs de l'HOMA-IR ni de la reponse glycemique. Cependant, l'ASCa des taux de PTX3 etait proportionnelle au degre de forme physique dont le [VO.sub.2max] temoignait. Ces observations semblent indiquer que la PTX3 pourrait etre utile comme biomarqueur de la sante metabolique ainsi que pour evaluer l'efficacite de l'entrainement physique en presence d'obesite. [Traduit par la Redaction] Mots-cles : pentraxine 3, obesite, effort physique aerobie, resistance a l'insuline, forme cardiorespiratoire., Introduction Obesity is characterized as a chronic state of low-grade proinflammation by the enlargement of adipocytes and increased infiltration of circulating monocytes differentiated into resident adipose tissue macrophages (Weisberg et [...]

Autophagy is a critical molecular process in promoting cell survival against apoptosis. This study examined whether maximal aerobic exercise-mediated apoptosis in obesity might be underlying the involvement of autophagy in the peripheral blood mononuclear cells (PBMCs). Twelve healthy male subjects (6 obese and 6 normal-weight) were recruited to participate in a maximal graded exercise test on a treadmill. Obese subjects exhibited a significantly lower Bax, but a higher Bcl-2 protein level in conjunction with a reduced Bax/Bcl-2 AUCi compared to normal-weight subjects following exercise. Furthermore, a greater LC3-II/LC3-I ratio and LC3-II/LC3-I AUCi was observed in obese subjects compared to normal-weight subjects. LC3-II/LC3-I AUCi was also positively associated with obesity-associated parameters (BMI, waist/hip circumference, and fasting insulin level), but was negatively correlated with Bax/Bcl-2 AUCi. These findings demonstrate that maximal aerobic exercise differentially mediates the intrinsic apoptotic pathway and autophagic activity in human PBMCs isolated from obese compared to normal-weight individuals. [ABSTRACT FROM AUTHOR]