The impact of obesity on pentraxin 3 and inflammatory milieu to acute aerobic exercise

Plasma pentraxin-3 levels and its role in childhood obesity-Is it anti-inflammatory? A matched group study

OBJECTIVE

Obesity has been associated with chronic low-grade systemic inflammation. This study aimed to investigate the relationship of pentraxin-3 (PTX-3) with anthropometric measurements, dietary content and physical activity level in children.

DESIGN

A matched group study.

PATIENTS

This study was conducted with 91 children aged 6-17 years, divided into two groups: "non-obese group" (Body Mass Index Standard Deviation Score [BMI SDS] <95th percentile) and "obese group" (BMI SDS ≥95th percentile).

MEASUREMENTS

Plasma PTX-3 levels.

RESULTS

The mean age of 91 children included in the study was 12.34 ± 2.86 years. Plasma PTX-3 levels were significantly higher in obese children (p = .028). No significant correlation was found between BMI SDS and plasma PTX-3 values, but a weak positive correlation was found when physical activity level was controlled (r = .176, p = .049). In addition, it was found that fat mass was a partial mediator of plasma PTX-3 level, and an increase in the amount of subcutaneous adipose tissue negatively affected plasma PTX-3 level. Plasma PTX-3 level showed a weak positive correlation (r = .223, p = .017) with physical activity score and dietary polyunsaturated fatty acid intake, while a weak negative correlation with neutrophil-to-lymphocyte ratio. One unit increase in physical activity score or polyunsaturated fatty acid level caused 0.730 and 2.061 unit increases in plasma PTX-3 level, respectively; while one unit increase in dietary fat intake caused 0.413-unit decrease.

CONCLUSION

There was an indirect relationship between the amount of subcutaneous adipose tissue and PTX-3 level. The results of our study suggested that plasma PTX-3 was associated with lower levels of inflammation in children.

Interleukin-6 is not involved in appetite regulation following moderate-intensity exercise in males with normal weight and obesity

OBJECTIVE

In obesogenic states and after exercise, interleukin (IL)-6 elevations are established, and IL-6 is speculated to be an appetite-regulating mechanism. This study examined the role of IL-6 on exercise-induced appetite regulation in sedentary normal weight (NW) males and those with obesity (OB).

METHODS

Nine NW participants and eight participants with OB completed one non-exercise control (CTRL) and one moderate-intensity continuous training (MICT; 60 minutes, 65% V̇O2max ) session. IL-6, acylated ghrelin, active peptide tyrosine-tyrosine3-36 , active glucagon-like peptide-1, and overall appetite perceptions were measured fasted, pre exercise, and 30, 90, and 150 minutes post exercise.

RESULTS

Fasted IL-6 concentrations were elevated in OB (p = 0.005,η p 2  = 0.419); however, increases following exercise were similar between groups (p = 0.934,η p 2  = 0.000). Acylated ghrelin was lower in OB versus NW (p < 0.017, d > 0.84), and OB did not respond to MICT (p > 0.512, d < 0.44) although NW had a decrease versus CTRL (p < 0.034, d > 0.61). IL-6 did not moderate/mediate acylated ghrelin release after exercise (p > 0.251). There were no observable effects of MICT on tyrosine-tyrosine3-36 , glucagon-like peptide-1, or overall appetite (p > 0.334,η p 2  < 0.062).

CONCLUSIONS

These results suggest that IL-6 is not involved in exercise-induced appetite suppression. Despite blunted appetite-regulatory peptide responses to MICT in participants with OB, NW participants exhibited decreased acylated ghrelin; however, no differences in appetite perceptions existed between CTRL and MICT or NW and OB.

Melatonin reduces muscle damage, inflammation and oxidative stress induced by exhaustive exercise in people with overweight/obesity

BACKGROUND

Intense physical exercise leads to inflammation, oxidative stress and muscle damage, and these responses are of greater magnitude in people with obesity. Melatonin (MLT) is considered an endogenous antioxidant which may have beneficial effects against inflammation, oxidative stress and promote tissue repair after exercise. The aim of this study was to examine the effect of MLT on inflammatory parameters, oxidative stress and muscle damage in people with overweight/obesity after a high-intensity interval exercise (HIIE).

METHODS

A total of 23 subjects with obesity (9 men and 14 women) age: 33.26 ± 9.81 years, BMI: 37.75 ± 8.87 kg.m-2 were randomized to participate in two experimental sessions: HIIE + Placebo and HIIE + MLT (3 mg). The HIIE protocol corresponds to 8 intervals of 1 min (90% of the maximal aerobic power (MAP)) alternating with 2 min recovery (45% of the MAP). Blood samples were drawn before and 5 min after each exercise session.

RESULTS

MLT ingestion attenuated the increase of inflammation (C-reactive protein, white blood cells (P < 0.001, ηp2 = 0.45; for both) and Neutrophils (P < 0.01, ηp2 = 0.36)) and hepatic and muscle damage (Aspartate aminotransferase (P < 0.01, ηp2 = 0.25), Alanine aminotransferase (P < 0.01, ηp2 = 0.27) and Creatine kinase (P = 0.02, ηp2 = 0.23). MLT also attenuated the exercise induced lipid and protein peroxidation (i.e., Malondialdehyde (P = 0.03, ηp2 = 0.19) and AOPP (P < 0.001, ηp2 = 0.55)). Concerning the antioxidant status, MLT intake increased Thiol (P < 0.01, ηp2 = 0.26) and Catalase (P < 0.01, ηp2 = 0.32) and decreased Uric acid (P = 0.02, ηp2 = 0.2) and Total bilirubin (P < 0.01, ηp2 = 0.33).

CONCLUSIONS

MLT intake before HIIE reduced muscle damage by modulating oxidative stress and preventing overexpression of the pro-inflammatory mediators in people with obesity.

Impact of acute high-intensity interval exercise on plasma pentraxin 3 and endothelial function in obese individuals-a pilot study

PURPOSE

Pentraxin 3 (PTX3) has been shown to be a predictor of endothelial dysfunction in patients with increased risk of cardiovascular disease (CVD) (e.g., obesity). Circulating PTX3 concentrations are dysregulated in obese individuals and are elevated following acute aerobic exercise. High-intensity interval exercise (HIIE) has been demonstrated to be as effective as continuous moderate-intensity exercise in improving endothelial function, as indicated by brachial artery flow-mediated dilation (BAFMD), in patients with CVD. Therefore, the purpose of this study was to examine the effect of acute HIIE on plasma PTX3 and BAFMD responses in obese individuals.

METHODS

Eight obese and six normal-weight young males participated in acute HIIE (4 intervals of 4 min at 80-90% of VO_2max; 3 min of active recovery at 50-60% VO_2max). Plasma PTX3 and BAFMD were measured prior to, immediately following exercise, and one and 2 hours into recovery.

RESULTS

Plasma PTX3 concentrations significantly increased following HIIE, yet the PTX3 response to HIIE was significantly blunted in obese compared to normal-weight participants. While the kinetic responses of BAFMD were also significantly different in obese compared to normal-weight participants, similar increases above the baseline were observed 2 hours into recovery in both groups. Finally, plasma PTX3 concentrations were not associated with BAFMD at baseline or in response to HIIE.

CONCLUSION

The utilization of HIIE may serve as a time-efficient exercise prescription strategy to transiently improve endothelial function, independent of elevated plasma PTX3 concentrations, in obese individuals.

Meta-inflammatory state and insulin resistance can improve after 10 weeks of combined all-extremity high-intensity interval training in sedentary overweight/obese females: a quasi-experimental study

OBJECTIVE

The effects of exercise training on suppression of inflammation have been proposed as a therapeutic approach in recent years to modify the obesity-induced inflammatory status and immunometabolic disorders. The present study aimed to assess the impacts of an all-extremity combined high-intensity interval training (HIIT) on inflammatory state and glycolipid metabolism in young sedentary overweight and obese females.

METHOD

This was an quasi-experimental study which was applied by comparing two groups. The participants were allocated to two active (AG, n = 15) and inactive (IG, n = 15) groups. The serum level of adiponectin, interleukin (IL)-10, pentraxin 3 (PTX3), and tumor-necrosis factor α (TNFα) was measured in all subjects. Also, glycolipid metabolism was assessed by measuring the fasting lipid profile parameters, glucose, and insulin levels and calculating the homeostasis model assessment of insulin resistance (HOMA2-IR).

RESULTS

Following a 10-week combined all-extremity HIIT in the active subjects, the TNFα, PTX3/IL-10, and TNFα/adiponectin were significantly reduced. However, the absolute levels of adiponectin, IL-10, and PTX3 remained unchanged. Additionally, a significant decrease was found in insulin, LDL, and HOMA2-IR, while insulin sensitivity and HDL levels showed a significant increase in the active group compared to the inactive group.

CONCLUSIONS

Our 10-week time-efficient combined all-extremity HIIT promoted an anti-inflammatory state and glycolipid metabolism improvement, suggesting this protocol as a practical therapeutic approach in sedentary obese females.

Aerobic Training Down-Regulates Pentraxin 3 and Pentraxin 3/Toll-Like Receptor 4 Ratio, Irrespective of Oxidative Stress Response, in Elderly Subjects

Reactive oxygen and nitrogen species-mediated cellular aging has been linked to diseases such as atherothrombosis and cancer. Although pentraxin 3 (PTX3) is associated with aging-related diseases via TLR4-dependent anti-inflammatory effects, its relationship with oxidative stress in aging remains to be elucidated. Exercise is proposed as the key intervention for health maintenance in the elderly. This study aimed to examine the association of PTX3 levels with changes in oxidative stress in both plasma and peripheral blood mononuclear cells (PBMCs), following aerobic training in elderly adults. Nine trained and five controls participated in an eight-week aerobic training protocol. Enzyme-linked immunosorbent assay (ELISA) and Western blot analyses were used to determine PTX3, toll-like receptor 4 (TLR4), and levels of oxidative stress biomarkers [3-nitrotyrosine (3NT), 4-hydroxynonenal (4-HNE), glutathione (GSH), protein carbonyl (PC), reactive oxygen/ nitrogen species (ROS/RNS), and trolox equivalent antioxidant capacity (TEAC)] in plasma and/or PBMCs. Results showed a down-regulation of PTX3 expression in PBMCs following aerobic training, along with decreased PTX3/TLR4 ratios. Oxidative stress responses in PBMCs remained unchanged with the exercise protocol. Comparable levels of plasma PTX3 and oxidative stress biomarkers were observed in trained vs. control groups. No correlation was found between PTX3 and any oxidative stress biomarkers following training. These findings demonstrated the down-regulation of PTX3 and PTX3/TLR4 ratio, irrespective of oxidative stress response, in elderly adults following eight weeks of aerobic training.

A Vegetable and Fish Dietary Pattern Is Positively Associated with Skeletal Muscle Mass in Korean Men

Isolating the effects of a single nutrient or food in relation to health outcomes including increased skeletal muscle mass is a challenging task because dietary constituents are highly correlated and synergistic. Hence, diet pattern analysis may be used to investigate the role of certain diets in health outcomes. The present study investigated the dietary patterns and their relationship to skeletal muscle mass in Korean adults. Data were extracted from the 2008–2011 Korea National Health and Nutrition Examination Surveys. To explore the dietary patterns of the study subjects, factor analysis was performed using data obtained from a 24-hour recall. The skeletal muscle index according to dietary pattern scores was then investigated to estimate the changes in skeletal muscle mass. Three patterns were initially identified from the factor analysis. Of these vegetables and fish (VF) pattern was the primary factor with high reliability and was a common factor in sex-separated analyses. The VF pattern scores were positively associated with increased skeletal muscle mass in both men and women. Further analysis according to quartile levels of VF pattern scores showed a positive association between skeletal muscle mass and VF pattern in men but not in women. These results suggest that dietary patterns focused on vegetables and seafoods may contribute to increased skeletal muscle mass in Korean men but that sex difference should be considered in nutrition care for skeletal muscle health.

The comparative analysis of phenotypic and whole transcriptome gene expression data of ascites susceptible versus ascites resistant chickens

Ascites syndrome (AS) is a metabolic disorder that mainly occurs at later ages of meat-type chickens. Despite many research, there is no consensus about the origin of this syndrome. Our main purpose were to investigate the syndrome using both phenotypic and RNA-Seq data to elucidate the most causative factors predisposing the birds to AS. Phenotypic data analysis showed that AS indicator traits (AITs) were moderate to high heritable. Inexistence of consistent direct genetic correlation between AITs and growth related traits, indicated that neither faster growth rate nor heavier body weight is the most causative factor affecting the susceptibility of broilers to AS. However, respiratory capacity was revealed to be the most probable factor predisposing the birds to AS, as both lung weight and lung percentage were negatively correlated with AITs. Transcriptomic data analysis revealed 125 differentially expressed genes (DEGs) between the ascitic and healthy groups. Up-regulated genes in ascitic group enriched mainly in gas transport biological process, while down-regulated genes involved in defense response to bacteria, biological adhesion, cell adhesion, killing of cells of another organism and cell division. Genetic association of the DEGs with human cardiovascular diseases suggested excessive heart problems of the ascitic chicks. Heart is, probably, the first tissue suffering from the incompetence of small respiratory system of the AS-susceptible chickens. In other word, tissue hypoxia, that causes free radicals to concentrate in heart cells, may be the commencement of events that finally result to heart failure, suffocation and death of chicks due to the AS.

Total energy intake according to the level of skeletal muscle mass in Korean adults aged 30 years and older: an analysis of the Korean National Health and Nutrition Examination Surveys (KNHANES) 2008-2011

BACKGROUND/OBJECTIVES

Since gain or loss of skeletal muscle mass is a gradual event and occurs due to a combination of lifestyle factors, assessment of dietary factors related to skeletal muscle is complicated. The aim of this study was to investigate the changes in total energy intake according to the level of skeletal muscle mass.

SUBJECTS/METHODS

A total of 8,165 subjects ≥ 30 years of age from the Korean National Health and Nutrition Examination Surveys (KNHANES) 2008-2011 were included in the analysis, and multivariate-adjusted regression analyses were performed to analyze the association of the quartiles of sarcopenia index (SI) with energy intake of the study population after adjusting for age and metabolic parameters.

RESULTS

The increase in SI quartile was in proportion to the gradual decrease in systemic lipids and the anthropometric measurement of fat accumulation (P < 0.001). Subjects in higher SI quartiles tended to consume more total energy and energy-producing nutrients than those in lower quartiles (P < 0.001). After age, body weight, alcohol consumption, and metabolic parameters were adjusted in the analysis, total energy intake gradually increased according to the increase in SI quartile, and the association between total energy intake and SI was more pronounced in men. However, the risk (odd ratio) of having a low SI was not affected by any single macronutrient intake.

CONCLUSIONS

In this study, total energy intake was positively associated with SI and relative skeletal mass in both men and women. However, no significant association or a weak association was observed between any single macronutrient intake and skeletal muscle mass. The data indicated that acquiring more energy intake within the normal range of energy consumption may help to maintain skeletal muscle mass.

Aerobic fitness alters the capacity of mononuclear cells to produce pentraxin 3 following maximal exercise

PURPOSE

Pentraxin 3 (PTX3) is a vital regulator of innate immune function. Although plasma PTX3 concentrations are elevated with aerobic fitness, the cellular functions of PTX3 remain unknown in aerobically trained and untrained subjects.

METHODS

Thirty individuals (aerobically trained = 15 and untrained = 15) participated in a maximal exercise protocol to examine ex vivo PTX3 production from isolated peripheral blood mononuclear cells (PBMCs) exposed to LPS or palmitate. The capacity of PTX3 to stimulate inflammatory cytokine production ex vivo was also examined.

RESULTS

Elevated plasma PTX3 concentrations prior to exercise were positively associated with the percent change (pre to post exercise) in plasma PTX3 concentrations in all subjects, independent of cardiorespiratory fitness (VO_2max). In addition, elevated plasma PTX3 concentrations in aerobically trained subjects at rest predicted changes in the LPS- and palmitate-stimulated PTX3 production from isolated PBMCs following acute exercise. In response to PTX3 simulation, the capacity of PBMCs to produce the anti-inflammatory cytokine IL-10 was decreased following acute exercise in all subject (no changes in IL-6, TGF-β1, and TNF-α observed). However, the percent change in IL-6 production was positively associated with VO_2max in all subjects, and in aerobically trained subjects only, positively associated with elevated plasma PTX3 concentrations at rest and in response to acute exercise.

CONCLUSION

These results suggest that aerobic training enhances the utilization of plasma PTX3 concentrations to predict the capacity of mononuclear cells to produce PTX3, and potentially, its reciprocal role of PTX3 as an initiator of the innate immune response following maximal exercise.

Plasma pentraxin 3 and glucose kinetics following acute high-intensity interval exercise versus continuous moderate-intensity exercise in healthy men

Pentraxin 3 (PTX3) is mainly synthesized and released by neutrophils to help regulate innate immunity. While plasma PTX3 concentrations are associated with improved glucose metabolism and overall metabolic health, there is evidence that significant elevations in plasma glucose downregulate circulating levels of PTX3. To examine whether this relationship would be altered in response to exercise, this study investigated the kinetics of the plasma glucose and PTX3 responses following high-intensity interval exercise (HIIE) and continuous moderate-intensity exercise (CMIE). It was hypothesized that the increased concentrations of plasma glucose following HIIE compared with CMIE would be associated with an attenuated plasma PTX3 response. Eight healthy male subjects participated in both HIIE and CMIE protocols administered as a randomized, counterbalanced design. Linear mixed models for repeated measures revealed that the overall plasma glucose response was greater following HIIE compared with CMIE (protocol × time effect: p = 0.037). Although the plasma PTX3 response was higher only at 19 min into HIIE compared with CMIE (protocol × time effect: p = 0.013), no relationships were observed between plasma glucose and PTX3 either at baseline or in response to both exercise protocols, as indicated by the area under the curve "with respect to increase" analysis. Our results indicate that exercise-mediated plasma PTX3 concentrations are independent of the plasma glucose response. In addition, the present study suggests that the neutrophil-mediated innate immune response, as indicated by plasma PTX3 response, may be activated earlier during HIIE compared with CMIE.

Update on the role of Pentraxin 3 in atherosclerosis and cardiovascular diseases

Pentraxin 3 (PTX3) is an acute-phase protein that was recently demonstrated to play pleiotropic activities in cardiovascular (CV) diseases. Tumor necrosis factor and interleukins up-regulates PTX3 transcription in different cell types (i.e. endothelial cells, phagocytes, smooth muscle cells, fibroblasts and glial cells) involved in atherogenesis. By interacting with numerous ligands, PTX3 acts as a modulatory molecule of complement system, inflammatory response, angiogenesis, and vascular/tissue remodeling. Experimental data point to a beneficial role of PTX3 in atherosclerotic plaque development and vulnerability. Animal studies indicated a protective role of PTX3 signaling in ischemic/reperfusion injury and failing heart. Clinical studies have so far provided contrasting results, highlighting a debated role of PTX3 as an active mediator of endothelial dysfunction, atherosclerotic plaque vulnerability and worse outcome after ischemic events. Therefore, substantial evidence suggests a dual role of PTX3 as modulator or amplifiers of the innate immune response. The final result of PTX3 activation might be determined by a fine tuning of time, space and environmental signals. The aim of this review is to provide an overview of biological properties of PTX3 in CV diseases and to discuss the ability of PTX3 to act as a crossroad between pro- and anti-inflammatory pathways.

Exercise reduced pentraxin 3 levels produced by endotoxin-stimulated human peripheral blood mononuclear cells in obese individuals

The purpose of this study was to determine whether obesity would reduce the capacity of peripheral blood mononuclear cells (PBMCs) to produce the anti-inflammatory protein pentraxin 3 (PTX3) in response to ex vivo stimulation with lipopolysaccharide (LPS), and if acute aerobic exercise would enhance this PTX3 production capacity. In addition, the inter-relationships of LPS-induced PTX3 with the inflammatory cytokines (interleukin 6 [IL-6], IL-10, and tumor necrosis factor alpha) were examined. Twenty-one healthy subjects (10 obese and 11 normal-weight) performed an acute bout of aerobic exercise at 75% VO_2max. The capacity of PBMCs to produce PTX3 ex vivo following LPS stimulation was the same in obese and normal-weight subjects at rest, and decreased equally in both subject groups following acute aerobic exercise. This is in contrast to plasma PTX3, which is lower in obese subjects at rest and increased equally in both obese and normal-weight subjects following exercise. In addition, ex vivo PTX3 production was positively associated with IL-6 and IL-10 in response to acute aerobic exercise ( r = 0.686, P = 0.020; r = 0.744, P = 0.009, respectively) in normal-weight, but not in obese individuals ( r = 0.429, P = 0.249; r = 0.453, P = 0.189, respectively). These findings indicate that concentrations of PTX3 observed in plasma are relatively independent of those produced by PBMCs ex vivo and the mechanisms associated with PTX3-mediated anti-inflammatory signaling may differ during obesity. Impact statement Our laboratory has previously demonstrated that obese individuals present with lower plasma concentrations of the anti-inflammatory protein pentraxin 3 (PTX3), whereas acute aerobic exercise increases plasma PTX3 levels similarly compared to normal-weight individuals. As a follow-up, the present study demonstrates that PBMCs isolated from obese and normal-weight individuals produce comparable amounts of PTX3 ex vivo in response to lipopolysaccharide (LPS). Furthermore, given that acute aerobic exercise reduced the ex vivo production of PTX3 in both groups, our results clearly indicate that plasma PTX3 levels are relatively independent of those produced by PBMCs ex vivo. In addition, our findings suggest that the mechanisms associated with PTX3-mediated production of the anti-inflammatory cytokine interleukin 10 may be impaired in obese individuals, and thus provides a key finding necessary for the elucidation of PTX3's role in the mediation of anti-inflammatory profiles and the subsequent amelioration of inflammatory disease during obesity.

The Potential Role of Aerobic Exercise-Induced Pentraxin 3 on Obesity-Related Inflammation and Metabolic Dysregulation

Obesity is defined as the excess accumulation of intra-abdominal body fat, resulting in a state of chronic, low-grade proinflammation that can directly contribute to the development of insulin resistance. Pentraxin 3 (PTX3) is an acute-phase protein that is expressed by a variety of tissue and cell sources and provides an anti-inflammatory property to downregulate the production of proinflammatory cytokines, in particular interleukin-1 beta and tumor necrosis factor alpha. Although PTX3 may therapeutically aid in altering the proinflammatory milieu in obese individuals, and despite elevated expression of PTX3 mRNA observed in adipose tissue, the circulating level of PTX3 is reduced with obesity. Interestingly, aerobic activity has been demonstrated to elevate PTX3 levels. Therefore, the purpose of this review is to discuss the therapeutic potential of PTX3 to positively regulate obesity-related inflammation and discuss the proposition for utilizing aerobic exercise as a nonpharmacological anti-inflammatory treatment strategy to enhance circulating PTX3 concentrations in obese individuals.

Pentraxin 3 is an anti-inflammatory protein associated with lipid-induced interleukin 10 in vitro

Pentraxin 3 (PTX3) is an acute phase protein expressed in response to pro-inflammatory stimuli during atherosclerosis. However, recent findings suggest that PTX3 is a counter-regulatory protein which enhances the anti-inflammatory response.

OBJECTIVE

Therefore, the capacity of PTX3 to alter the inflammatory milieu following in vitro stimulation of PBMCs with the pro-inflammatory lipid, palmitate, was examined.

METHODS

PBMCs from 17 healthy male donors were isolated and cultured under four separate conditions; 200μmol/L palmitate, a physiologically relevant concentration of PTX3, in combination (pal+PTX3), and an unstimulated time-course control.

RESULTS

Palmitate-induced production of the counter-regulatory protein PTX3 was positively associated with the production of the anti-inflammatory cytokine interleukin 10 (IL-10) following in vitro stimulation of human PBMCs. Furthermore, stimulation of PBMCs in vitro with 500pg/mL PTX3 elicited a significantly greater increase in IL-10 production compared to the palmitate stimulated conditions. However, PTX3 stimulation did not result in the production of the pro-inflammatory cytokines IL-1β, IL-6, and tumor necrosis factor alpha, and when combined with palmitate, did not alter the pro-inflammatory milieu from PBMCs in this study.

CONCLUSION

These findings provide evidence supporting the role of PTX3 as a mediator of the anti-inflammatory response in physiologically relevant conditions, and suggests that PTX3 counter regulates the development of atherosclerosis by enhancing the production of IL-10.

Association of pentraxin 3 with insulin resistance and glucose response following maximal aerobic exercise in obese and normal-mass individuals

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 (VO2max). 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 VO2max). 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.

Elevated pentraxin 3 level at the early stage of exercise training is associated with reduction of arterial stiffness in middle-aged and older adults

Regular exercise improves aging-induced deterioration of arterial stiffness, and is associated with elevated production of pentraxin 3 (PTX3) and anti-inflammatory as well as anti-atherosclerotic effects. However, the time-dependent effect of exercise training on arterial stiffness and PTX3 production remains unclear. The purpose of this study was to investigate the time course of the association between the effects of training on the circulating PTX3 level and arterial stiffness in middle-aged and older adults. Thirty-two healthy Japanese subjects (66.2±1.3 year) were randomly divided into two groups: training (exercise intervention) and sedentary controls. Subjects in the training group completed 8 weeks of aerobic exercise training (60-70% peak oxygen uptake (VO2peak) for 45 min, 3 days per week); during the training period, we evaluated plasma PTX3 concentration and carotid-femoral pulse wave velocity (cfPWV) every 2 wk. cfPWV gradually declined over the 8-week training period, and was significantly reduced after 6 and 8 week of exercise intervention (P<0.05). Plasma PTX3 level was significantly increased after 4 weeks of the intervention (P<0.05). In addition, the exercise training-induced reduction in cfPWV was negatively correlated with the percent change in plasma PTX3 level after 6 week (r=-0.54, P<0.05) and 8 weeks (r=-0.51, P<0.05) of the intervention, but not correlated at 4 weeks. Plasma PTX3 level was elevated at the early stage of the exercise training intervention, and was subsequently associated with training-induced alteration of arterial stiffness in middle-aged and older adults.

Honokiol ameliorates endothelial dysfunction through suppression of PTX3 expression, a key mediator of IKK/IκB/NF-κB, in atherosclerotic cell model

Pentraxin 3 (PTX3) was identified as a marker of the inflammatory response and overexpressed in various tissues and cells related to cardiovascular disease. Honokiol, an active component isolated from the Chinese medicinal herb Magnolia officinalis, was shown to have a variety of pharmacological activities. In the present study, we aimed to investigate the effects of honokiol on palmitic acid (PA)-induced dysfunction of human umbilical vein endothelial cells (HUVECs) and to elucidate potential regulatory mechanisms in this atherosclerotic cell model. Our results showed that PA significantly accelerated the expression of PTX3 in HUVECs through the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) pathway, reduced cell viability, induced cell apoptosis and triggered the inflammatory response. Knockdown of PTX3 supported cell growth and prevented apoptosis by blocking PA-inducted nitric oxide (NO) overproduction. Honokiol significantly suppressed the overexpression of PTX3 in PA-inducted HUVECs by inhibiting IκB phosphorylation and the expression of two NF-κB subunits (p50 and p65) in the IKK/IκB/NF-κB signaling pathway. Furthermore, honokiol reduced endothelial cell injury and apoptosis by regulating the expression of inducible NO synthase and endothelial NO synthase, as well as the generation of NO. Honokiol showed an anti-inflammatory effect in PA-inducted HUVECs by significantly inhibiting the generation of interleukin-6 (IL-6), IL-8 and monocyte chemoattractant protein-1. In summary, honokiol repaired endothelial dysfunction by suppressing PTX3 overexpression in an atherosclerotic cell model. PTX3 may be a potential therapeutic target for atherosclerosis.