Physical activity impacts immune homeostasis and leads to rapid and marked increase in cell-free DNA (cfDNA). However, the origin of cfDNA during exercise remains elusive and it is unknown if physical activity could improve or interfere with methylation based liquid biopsy. We analyzed the methylation levels of four validated CpGs representing cfDNA from granulocytes, lymphocytes, monocytes, and non-hematopoietic cells, in healthy individuals in response to exercise, and in patients with hematological malignancies under resting conditions. The analysis revealed that physical activity almost exclusively triggered DNA release from granulocytes, highlighting the relevance as a pre-analytical variable which could compromise diagnostic accuracy. Graphical Abstract

Although it is widely accepted that cancer-derived extracellular vesicles (EVs) carry DNA cargo, the association of cell-free circulating DNA (cfDNA) and EVs in plasma of healthy humans remains elusive. Using a physiological exercise model, where EVs and cfDNA are synchronously released, we aimed to characterize the kinetics and localization of DNA associated with EVs. EVs were separated from human plasma using size exclusion chromatography or immuno-affinity capture for CD9⁺, CD63⁺, and CD81⁺ EVs. DNA was quantified with an ultra-sensitive qPCR assay targeting repetitive LINE elements, with or without DNase digestion. This model shows that a minute part of circulating cell-free DNA is associated with EVs. During rest and following exercise, only 0.12% of the total cfDNA occurs in association with CD9⁺/CD63⁺/CD81⁺EVs. DNase digestion experiments indicate that the largest part of EV associated DNA is sensitive to DNase digestion and only ~20% are protected within the lumen of the separated EVs. A single bout of running or cycling exercise increases the levels of EVs, cfDNA, and EV-associated DNA. While EV surface DNA is increasing, DNAse-resistant DNA remains at resting levels, indicating that EVs released during exercise (ExerVs) do not contain DNA. Consequently, DNA is largely associated with the outer surface of circulating EVs. ExerVs recruit cfDNA to their corona, but do not carry DNA in their lumen.

Background: Systemic lupus erythematosus is a systemic autoimmune disease, which is associated with high cardiovascular risk, a predisposition to metabolic disorders, muscle wasting, and fatigue. Exercise therapy has become an important part of the long-term treatment of comorbidities in systemic lupus erythematosus. Exercise can lead to various benefits in patients with systemic lupus erythematosus such as increased aerobic capacity and exercise tolerance, resulting in an increased quality of life, decreased depression, and decreased fatigue. At the moment, no evidence-based treatment guidelines that recommend exercise for patients with systemic lupus erythematosus exist. Also, the efficacy of different training programs requires further investigation. Objective: This study focuses on the feasibility, efficacy, and safety of an internet-based exercise program in patients with systemic lupus erythematosus. Furthermore, we investigate the feasibility and efficiency of anaerobic training compared to aerobic training. Methods: Overall, patients with systemic lupus erythematosus from the Division of Nephrology, Rheumatology, and Immunology outpatient clinic of the University Medical Center Mainz who are clinically stable status are included and randomized in an aerobic exercise group (n=10), anaerobic exercise group (n=10), or treatment as usual group (n=10). After completing initial clinical testing and physical fitness tests, patients undergo supervised 12-week online exercise programs, receiving weekly individualized training plans adapted to their physical performance. The primary outcome is change in physical fitness (VO2 peak) after 12 weeks compared to baseline. Secondary outcomes are disease activity measured via laboratory results (complement, autoantibodies) and questionnaires, as well as changes in muscle mass (anaerobic exercise group), results of the Chair-Stand test, and measurements of circulating cell-free DNA and extracellular vesicles. Results: The study was registered in May 2019. Enrollment began in May 2019. Of 40 patients who were initially screened, 30 patients fulfilled the inclusion criteria and were included in the study; 1 participant withdrew prior to the start of the exercise program. Among the 25 patients who completed the study, no serious adverse events have been reported; 3 participants withdrew during the program (due to frequent colds, n=1; Crohn relapse, n=1; physical strain, n=1), and 1 participant has not yet completed the program. Data analysis is ongoing, and results are expected to be submitted for publication in January 2021. Conclusions: We expect the online exercise intervention to be a feasible and efficient tool to provide regular individualized exercise for patients with systemic lupus erythematosus. Trial Registration: ClinicalTrials.gov NCT03942718; http://clinicaltrials.gov/ct2/show/NCT03942718. International Registered Report Identifier (IRRID): DERR1-10.2196/18291

Background: Physical activity alleviates chronic stress. The latest research suggests a relationship between resilience and physical fitness. Beneficial adaptations of the hypothalamic-pituitary-adrenal axis, sympathetic nervous system, endocannabinoid system, and tryptophan pathway, which are induced by an active lifestyle, are considered to be conducive to resilience. However, detailed knowledge on the molecular link between the effects of acute and chronic physical exercise and improved resilience to stress in humans is missing. Moreover, the relationship between innate and acquired aerobic capacity and resilience is poorly understood. Objective: The aim of this study is to implement a human exercise intervention trial addressing the following main hypotheses: a high innate aerobic capacity is associated with high resilience to stress, and web-based physical exercise training improves aerobic capacity of physically inactive adults, which is accompanied by improved resilience. In this setting, we will analyze the relationship between resilience parameters and innate and acquired aerobic capacity as well as circulating signaling molecules. Methods: A total of 70 healthy, physically inactive (<150 minutes/week of physical activity) adults (aged 18-45 years) will be randomly assigned to an intervention or control group. Participants in the intervention group will receive weekly training using progressive endurance and interval running adapted individually to their remotely supervised home training performance via web-based coach support. A standardized incremental treadmill exercise test will be performed before and after the intervention period of 8 weeks to determine the innate and acquired aerobic capacity (peak oxygen uptake). Before and after the intervention, psychological tests and questionnaires that characterize parameters implicated in resilience will be applied. Blood and saliva will be sampled for the analysis of cortisol, lactate, endocannabinoids, catecholamines, kynurenic acid, and further circulating signal transducers. Statistical analysis will provide comprehensive knowledge on the relationship between aerobic capacity and resilience, as well as the capacity of peripheral factors to mediate the promoting effects of exercise on resilience. Results: The study was registered in October 2019, and enrollment began in September 2019. Of the 161 participants who were initially screened via a telephone survey, 43 (26.7%) fulfilled the inclusion criteria and were included in the study. Among the 55% (17/31) of participants in the intervention group and 45% (14/31) of participants in the control group who completed the study, no serious adverse incidents were reported. Of 43 participants, 4 (9%) withdrew during the program (for individual reasons) and 8 (19%) have not yet participated in the program; moreover, further study recruitment was paused for an indeterminate amount of time because of the COVID-19 pandemic. Conclusions: Our study aims to further define the physiological characteristics of human resilience, and it may offer novel approaches for the prevention and therapy of mental disorders via an exercise prescription. International Registered Report Identifier (IRRID): DERR1-10.2196/29712

Although it is widely accepted that cancer derived extracellular vesicles (EVs) carry DNA cargo, the association of cell-free circulating DNA (cfDNA) and EVs in plasma of healthy humans remains elusive. Using a physiological exercise model, where EVs and cfDNA are synchronously released, we aimed to characterize the kinetics and localization of DNA associated with EVs. EVs were separated from human plasma using size exclusion chromatography or immuno-affinity capture for CD9 ⁺ , CD63 ⁺ , and CD81 ⁺ EVs. DNA was quantified with an ultra-sensitive qPCR assay targeting repetitive LINE elements, with or without DNase digestion. This model shows that a minute part of circulating cell-free DNA is associated with EVs. During rest and following exercise, only 0.12 % of the total cfDNA occurs in association with CD9 ⁺ /CD63 ⁺ /CD81 ⁺ EVs. DNase digestion experiments indicate that the largest part of EV associated DNA is sensitive to DNase digestion and only ~20 % are protected within the lumen of the separated EVs. A single bout of running or cycling exercise increases the levels of EVs, cfDNA, and EV associated DNA. While EV surface DNA is increasing, DNAse-resistant DNA remains at resting levels, indicating that EVs released during exercise (ExerVs) do not contain DNA. Consequently, DNA is largely associated with the outer surface of circulating EVs. ExerVs recruit cfDNA to their corona, but do not carry DNA in their lumen.

Background: Societal measures to contain the spread of COVID-19 (eg, lockdown and contact restrictions) have been associated with decreased health and well-being. A multitude of prepandemic studies identified the beneficial effects of physical exercise on both physical and mental health. Objective: We report on the feasibility of a remote physical exercise intervention and its stress-buffering potential in 2 untrained cohorts: a pre–COVID-19 cohort that completed the intervention in 2019 and a lockdown cohort that started the intervention shortly before pandemic-related restrictions were implemented. Methods: In a randomized controlled trial, participants were assigned to either an intervention group (IG; pre–COVID-19 cohort: n=7 and lockdown cohort: n=9) or a control group (CG; pre–COVID-19 cohort: n=6 and lockdown cohort: n=6). IG participants received weekly individualized training recommendations delivered via web-based support. The intervention period was initially planned for 8 weeks, which was adhered to in the pre–COVID-19 cohort (mean 8.3, SD 0.5 weeks) but was extended to an average of 17.7 (SD 2.0) weeks in the lockdown cohort. Participants’ health parameters were assessed before and after the intervention: aerobic capacity was measured as peak oxygen uptake (VO2peak) via cardiopulmonary exercise testing. Depressive symptoms were scored via the depression subscale of the Brief Symptom Inventory-18. Results: Dropout rates were low in both cohorts in the IG (pre–COVID-19 cohort: n=0, 0% and lockdown cohort: n=2, 16.7%) and the CG (pre–COVID-19 cohort: n=0, 0% and lockdown cohort: n=2, 20%). The mean adherence to the training sessions of the IG for both cohorts was 84% (pre–COVID-19 cohort: SD 5.5% and lockdown cohort: SD 11.6%). Aligned rank transform ANOVAs in the lockdown cohort indicated deterioration of VO2peak and depressive symptoms from before to after the intervention in the CG but no longitudinal changes in the IG. Analyses in the pre–COVID-19 cohort revealed significant increases in VO2peak for the IG compared to the CG (P=.04) but no intervention effects on depressive symptoms. Conclusions: With low dropout rates and high adherence, the remote intervention was feasible for healthy adults under regular conditions and in the face of pandemic-related stressors. Moreover, our results hint at a stress-buffering effect as well as a buffering of a lockdown-induced deconditioning of remote physical exercise interventions in the pandemic scenario, which can be used in future studies to overcome equally stressful periods of life. However, due to limited statistical power, these findings should be replicated in similar scenarios. Trial Registration: German Clinical Trials Register DRKS00018078; https://drks.de/search/en/trial/DRKS00018078