title: Plasma cell-free mitochondrial DNA declines in response to prolonged moderate aerobic exercise.
abstract: Increased plasma cell-free mitochondrial DNA (cf-mDNA), a damage-associated molecular pattern (DAMP) produced by cellular injury, contributes to neutrophil activation/inflammation in trauma patients and arises in cancer and autoimmunity. To further understand relationships between cf-mDNA released by tissue injury, inflammation, and health benefits of exercise, we examined cf-mDNA response to prolonged moderate aerobic exercise. Seven healthy moderately trained young men (age = 22.4 ± 1.2) completed a treadmill exercise trial for 90 min at 60% VO2 max and a resting control trial. Blood was sampled immediately prior to exercise (0 min = baseline), during (+18, +54 min), immediately after (+90 min), and after recovery (R40). Plasma was analyzed for cf-mDNA, IL-6, and lactate. A significant difference in cf-mDNA response was observed between exercise and control trials, with cf-mDNA levels reduced during exercise at +54 and +90 (with or without plasma volume shift correction). Declines in cf-mDNA were accompanied by increased lactate and followed by an increase in IL-6, suggesting a temporal association with muscle stress and inflammatory processes. Our novel finding of cf-mDNA decline with prolonged moderate treadmill exercise provides evidence for increased clearance from or reduced release of cf-mDNA into the blood with prolonged exercise. These studies contrast with previous investigations involving exhaustive short-term treadmill exercise, in which no change in cf-mDNA levels were reported, and contribute to our understanding of differences between exercise- and trauma-induced inflammation. We propose that transient declines in cf-mDNA may induce health benefits, by reducing systemic inflammation.
authors.affiliation: Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana pshockett@selu.edu.
authors.forename: Penny E
authors.initials: PE
authors.lastname: Shockett
authors.affiliation: Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana.
authors.forename: Januka
authors.initials: J
authors.lastname: Khanal
authors.affiliation: Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana.
authors.forename: Alina
authors.initials: A
authors.lastname: Sitaula
authors.affiliation: Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana.
authors.forename: Christopher
authors.initials: C
authors.lastname: Oglesby
authors.affiliation: Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Ctr., Odessa, Texas.
authors.forename: William A
authors.initials: WA
authors.lastname: Meachum
authors.affiliation: Department of Obstetrics and Gynecology, Texas Tech University Health Sciences Ctr., Odessa, Texas.
authors.forename: V Daniel
authors.initials: VD
authors.lastname: Castracane
authors.affiliation: Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond, Louisiana.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Kraemer
mesh_terms: D004272:DNA, Mitochondrial / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods / Q000639:trends*; D006801:Humans; D008297:Male; D010950:Plasma Cells / Q000378:metabolism*; D013997:Time Factors; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial
keywords: Cell‐free DNA; DAMP; cell‐free mitochondrial DNA; damage‐associated molecular pattern; exercise; inflammation