Physical Exercise Promotes DNase Activity Enhancing the Capacity to Degrade Neutrophil Extracellular Traps

Effect of a 12-Week Walking Program Monitored by Global Physical Capacity Score (GPCS) on Circulating Cell-Free mtDNA and DNase Activity in Patients with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) involves low-grade mucosal inflammation. Among the various approaches capable of managing the symptoms, physical activity is still under investigation. Despite its benefits, it promotes oxidative stress and inflammation. Mitochondria impacts gut disorders by releasing damage-associated molecular patterns, such as cell-free mtDNA (cf-mtDNA), which support inflammation. This study evaluated the effects of a 12-week walking program on the cf-mtDNA and DNase in 26 IBS and 17 non-IBS subjects. Pro- and anti-inflammatory cytokines were evaluated by ELISA. Digital droplet PCR was used to quantify cf-mtDNA; DNase activity was assessed using a single radial enzyme diffusion assay. PCR-RFLP was used to genotype DNASE1 rs1053874 SNP. Significantly lower IL-10 levels were found in IBS than in non-IBS individuals. Exercise reduced cf-mtDNA in non-IBS subjects but not in IBS patients. DNase activity did not correlate with the cf-mtDNA levels in IBS patients post-exercise, indicating imbalanced cf-mtDNA clearance. Different rs1053874 SNP frequencies were not found between groups. The study confirms the positive effects of regular moderate-intensity physical activity in healthy subjects and its role in cf-mtDNA release and clearance. Walking alone might not sufficiently reduce subclinical inflammation in IBS, based on imbalanced pro- and anti-inflammatory molecules. Prolonged programs are necessary to investigate their effects on inflammatory markers in IBS.

High-intensity interval training reduces the induction of neutrophil extracellular traps in older men using live-neutrophil imaging as biosensor

Neutrophil extracellular trap formation (NETosis) is a mechanism used by neutrophils to capture pathogens with their own DNA. However, the exacerbation of this immune response is related to serious inflammatory diseases. Aging is known to lead to an excessive increase in NETosis associated with various diseases. Under this scenario, the search for strategies that regulate the release of NETosis in older people becomes relevant. High-intensity interval training (HIIT) involves repeated bouts of relatively intense exercise with alternating short recovery periods. This training has shown beneficial effects on health parameters during aging and disease. However, little is known about the potential role of HIIT in the regulation of NETosis in healthy older people. The aim of this study was to evaluate the induction of NETosis by serum from healthy young and older men, before and after 12 weeks of HIIT using healthy neutrophils as a biosensor. HIIT was performed 3 times per week for 12 weeks in young (YOUNG; 21 ± 1 years, BMI 26.01 ± 2.64 kg⋅m-2, n = 10) and older men (OLDER; 66 ± 5 years, BMI 27.43 ± 3.11 kg⋅m-2, n = 10). Serum samples were taken before and after the HIIT program and NETosis was measured with live cell imaging in donated neutrophils cultured with serum from the participants for 30 h. Our results showed that serum from older men at baseline induced greater baseline NETosis than younger men (p < 0.05; effect size, ≥0.8), and 12 weeks of HIIT significantly reduced (Interaction Effect, p < 0.05; effect size, 0.134) the induction of NETosis in older men. In conclusion, HIIT is a feasible non-invasive training strategy modulating NETosis induction. Additionally, the use of neutrophils as a biosensor is an effective method for the quantification of NETosis induction in real time.

Mechanisms underlying the beneficial effects of physical exercise on multiple sclerosis: focus on immune cells

Multiple sclerosis (MS) is a prevalent neuroimmunological illness that leads to neurological disability in young adults. Although the etiology of MS is heterogeneous, it is well established that aberrant activity of adaptive and innate immune cells plays a crucial role in its pathogenesis. Several immune cell abnormalities have been described in MS and its animal models, including T lymphocytes, B lymphocytes, dendritic cells, neutrophils, microglia/macrophages, and astrocytes, among others. Physical exercise offers a valuable alternative or adjunctive disease-modifying therapy for MS. A growing body of evidence indicates that exercise may reduce the autoimmune responses triggered by immune cells in MS. This is partially accomplished by restricting the infiltration of peripheral immune cells into the central nervous system (CNS) parenchyma, curbing hyperactivation of immune cells, and facilitating a transition in the balance of immune cells from a pro-inflammatory to an anti-inflammatory state. This review provides a succinct overview of the correlation between physical exercise, immune cells, and MS pathology, and highlights the potential benefits of exercise as a strategy for the prevention and treatment of MS.