Exercise training induces alteration of clock genes and myokines expression in tumor-bearing mice.

To investigate the impact of different exercise training schedules (following a fixed schedule or at random times of the day) on clock genes and myokine expression patterns in the skeletal muscle of tumor-bearing mice. Mice were divided into three groups: tumor (LLC), tumor + exercise training (LLC + T) always performed at the same time of the day (ZT2) and exercise training at random times of the day (ZTAlt). Mice were inoculated subcutaneously with Lewis lung carcinoma cells. The gastrocnemius muscle was dissected and the clock gene expression (Clock/Per1/Per2/Per3/Rev-Erbα/GAPDH) was investigated by quantitative reverse transcription polymerase chain reaction with SYBR® Green. Myokine content in muscle (tumour necrosis factor alpha/IL-10/IL-4) was assessed by enzyme-linked immunosorbent assay. At the end of the protocol, the trained groups showed a reduction in total weight, when compared to Lewis lung carcinoma. Tumor weight was lower in the LLC + T (ZTAlt), when compared to LLC. Clock gene mRNA expression showed a significant increase for ZT20 in the groups that performed physical exercise at LLC + T (ZTAlt), when compared with LLC. The Per family showed increased mRNA expression in ZT4 in both trained mice groups, when compared with LLC. LLC + T (ZTAlt) presented reduction of the expression of anti-inflammatory myokines (Il-10/IL-4) during the night, compared with LLC + T(ZT2). Exercise training is able to induce marked modification of clock gene expression and of the production of myokines, in a way that is dependent on schedule exercise training strategy. Taken together, the results show that exercise is a potent Zeitgeber and may thus contribute to change clock genes expression and myokines that are able to reduce the tumor weight.

Improvement in the anti-inflammatory profile with lifelong physical exercise is related to clock genes expression in effector-memory CD4+ T cells in master athletes.

PURPOSE: Ageing is associated with alterations in the immune system as well as with alterations of the circadian rhythm. Immune cells show rhythmicity in execution of their tasks. Chronic inflammation (inflammaging), which is observed in the elderly, is mitigated by lifelong exercise. The aimed this study was to determine the acute effect of a maximal exercise test on clock genes, regulatory proteins and cytokine expression, and evaluate the effect of lifelong exercise on the expression of clock genes in subpopulations of effector-memory (EM) CD4+ and CD8+T cells and the association of these processes with the inflammatory profile. Therefore, this study aimed to investigate the expression of clock genes in subpopulations of effector memory (EM) CD4+ and CD8+ T cells in master athletes and healthy controls and further associate them with systemic inflammatory responses to acute exercise. METHODS: The study population comprised national and international master athletes (n = 18) involved in three sports (athletics, swimming and judo). The control group (n = 8) comprised untrained healthy volunteers who had not participated in any regular and competitive physical exercise in the past 20 years. Anthropometric measurements and blood samples were taken before (Pre), 10 min after (Post) and 1 h after (1 h Post) a maximal cycle ergometer test for the determination of maximum oxygen consumption (VO2 max). The subpopulations of EM CD4+ and CD8+ T cells were purified using fluorescenceactivated cell sorting. RNA extraction of clock genes (CLOCK, BMAL1, PER1, PER2, CRY1, CRY2, REV-ERBα, REV-ERBß, RORa, RORb and RORc) in EM CD4+ and EM CD8+ T cells as well as regulatory proteins (IL-4, IFN-γ, Tbx21, PD-1, Ki67, NF-kB, p53 and p21) in EM CD4+ T cells was performed. The serum concentration of cytokines (IL-8, IL-10, IL-12p70 and IL-17A) was measured. RESULTS: The master athletes showed better physiological parameters than the untrained healthy controls (P < 0.05). The levels of cytokines increased in master athletes at Post compared with those at Pre. The IL-8 level was higher at 1 h Post, whereas the IL-10 and IL-12p70 levels returned to baseline. There was no change in IL-17A levels (P < 0.05). The clock genes were modulated differently in CD4+ T cells after an acute session of exercise in a training status-dependent manner. CONCLUSION: The synchronization of clock genes, immune function and ageing presents new dimensions with interesting challenges. Lifelong athletes showed modified expression patterns of clock genes and cytokine production associated with the physical fitness level. Moreover, the acute bout of exercise altered the clock machinery mainly in CD4+ T cells; however, the clock gene expressions induced by acute exercise were different between the master athletes and control group.

Aging with rhythmicity. Is it possible? Physical exercise as a pacemaker.

Aging is associated with gradual decline in numerous physiological processes, including a reduction in metabolic functions and immunological system. The circadian rhythm plays a vital role in health, and prolonged clock disruptions are associated with chronic diseases. The relationships between clock genes, aging, and immunosenescence are not well understood. Inflammation is an immune response triggered in living organisms in response to the danger associated with pathogens and injury. The term 'inflammaging' has been used to describe the chronic low-grade-inflammation that develops with advancing age and predicts susceptibility to age-related pathologies. Equilibrium between pro-and anti-inflammatory cytokines is needed for healthy aging and longevity. Sedentary and poor nutrition style life indices a disruption in circadian rhythm promoting an increase in pro-inflammatory factors or leads for chronic low-grade inflammation. Moreover, signals mediated by pro-inflammatory cytokines, such as tumor necrosis factor-alpha and interleukin-6, might accentuate of the muscle loss during aging. Circadian clock is important to maintain the physiological functions, as maintenance of immune system. A strategy for imposes rhythmicity in the physiological systems may be adopted of exercise training routine. The lifelong regular practice of physical exercise decelerates the processes of aging, providing better quality and prolongation of life. Thus, in this review, we will focus on how aging affects circadian rhythms and its relationship to inflammatory processes (inflammaging), as well as the role of physical exercise as a regulator of the circadian rhythm, promoting aging with rhythmicity.

Macrophage immunophenotype but not anti-inflammatory profile is modulated by peroxisome proliferator-activated receptor gamma (PPARγ) in exercised obese mice.

Moderate aerobic training may be therapeutic for chronic low-grade inflammatory diseases due to the associated anti-inflammatory response that is mediated by immune cells. The peroxisome proliferator-activated receptor gamma (PPARγ) regulates the M1 (pro-inflammatory) and M2 (anti-inflammatory) polarization, as well as the immunometabolic response of macrophages. Against this background, the present study seeks to clarify whether the conditional deletion of PPARγ in macrophages would have any effect on the anti-inflammatory role of moderate aerobic training. To test this hypothesis, two mice strains were used: PPARγ LyzCre+/+ (KO) and littermates control animals (WT). Each genotype was divided into 1) sedentary high-fat diet (HF) and 2) high-fat diet and moderate aerobic training (HFT) (n = 5-8 per group). The experimental protocol lasted for 12 weeks, comprising 4 weeks of HF diet only and 8 weeks of HF diet and aerobic training (5 times/week, 50-60 minutes/day at 60% of maximum speed). Metabolic analyses were carried out on the serum glucose homeostase, adipose tissue morphology and cytokine content, and macrophage cytokine production.Immunophenotyping and gene expression were also performed. KO male mice were more prone to hypertrophy in the subcutaneous adipose tissue, though only the IL-1ß (p = 0.0049) was higher compared to the values observed in WT animals. Peritoneal macrophages from KO animals exhibited a marked inflammatory environment with an increase in TNF-α (p = 0.0008), IL- 1ß (p = 0.0017), and IL-6 (p < 0.0001) after lipopolysaccharide stimulation. The moderate aerobic training protected both genotypes from weight gain and reduced the caloric intake in the KO animals. Despite the attenuation of the M2 marker CD206 (p < 0.001) in the absence of PPAR-γ, the aerobic training modulated cytokine production in LPS stimulated peritoneal macrophages from both genotypes, reducing proinflammatory cytokines such as TNF-α (p = 0.0002) and IL-6 (p < 0.0001). Overall, our findings demonstrate the essential role of PPARγ in macrophage immunophenotypes. However, the deletion of PPARγ did not inhibit the exercise-mediated anti-inflammatory effect, underscoring the important role of exercise in modulating inflammation.

Regulation of autophagy as a therapy for immunosenescence-driven cancer and neurodegenerative diseases: The role of exercise.

Aging is one of the risk factors for the development of low-grade inflammation morbidities, such as several types of cancer and neurodegenerative diseases, due to changes in the metabolism, hormonal secretion, and immunosenescence. The senescence of the immune system leads to improper control of infections and tissue damage increasing age-related diseases. One of the mechanisms that maintain cellular homeostasis is autophagy, a cell-survival mechanism, and it has been proposed as one of the most powerful antiaging therapies. Regular exercise can reestablish autophagy, probably through AMP-activated protein kinase activation, and help in reducing the age-related senescence diseases. Therefore, in this study, we discuss the effects of exercise training in immunosenescence and autophagy, preventing the two main age-related disease, cancer and neurodegeneration.

Short-term treatment with metformin reduces hepatic lipid accumulation but induces liver inflammation in obese mice.

The study aimed to evaluate the metabolic and inflammatory effects of short-term treatments (10 days) with metformin (MET) on the NAFLD caused by a high-fat diet (HFD) in C57BL/6 mice. After the treatment, histological liver slices were obtained, hepatocytes and macrophages were extracted and cultured with phosphate buffered saline, LPS (2.5 µg/mL) and MET (1 µM) for 24 h. Cytokine levels were determined by ELISA. NAFLD caused by the HFD was partially reduced by MET. The lipid accumulation induced by the HFD was not associated with liver inflammation; however, MET seemed to promote pro-inflammatory effects in liver, since it increased hepatic concentration of IL-1ß, TNF-α, IL-6, MCP-1 and IFN-γ. Similarly, MET increased the concentration of IL-1ß, IL-6 in hepatocyte cultures. However, in macrophages culture, MET lowered levels of IL-1ß, IL-6 and TNF-α stimulated by LPS. Overall, MET reduced liver NAFLD but promoted hepatocyte increase in pro-inflammatory cytokines, thus, leading to liver inflammation.