title: Neutrophil and monocyte responses to downhill running: Intracellular contents of MPO, IL-6, IL-10, pstat3, and SOCS3.
abstract: High-intensity exercise results in immune activation. This study determined whether (a) there is concordance between serum MPO and neutrophil and/or monocyte intracellular MPO content; (b) peripheral blood mononuclear cells respond to inflammatory interleukins (ILs) by increasing intracellular signaling. Healthy male (n = 12) volunteers participated in high-intensity running (12 × 5 min, 10% decline, 15 km/h). Blood sample (pre, post, 4 h) analyses included serum concentrations of IL-1β, IL-1ra, IL-4, IL-6, IL-8, IL-10, matrix metalloprotease-9 (MMP-9) and creatine kinase (CK). Intracellular IL-6, IL-10, MPO and STAT3/SOCS3 signaling were assessed in mononuclear cells. CK (1573 ± 756 u/L), MMP-9 (101 ± 27 ng/mL), neutrophil (9.89 ± 0.76 × 10(9) cells/L) and monocyte counts (1 ± 0.08 × 10(9) cells/L) increased at 4 h. At 4 h serum (7.1 ± 1.3 ng/mL) and monocyte MPO (1.7-fold) increased, whereas neutrophil MPO decreased (0.8-fold). Intracellular monocyte IL-10 and IL-6 decreased by 15% and 20-30%, respectively, coinciding with elevations in serum IL-10 of 14.5 ± 4.7 pg/mL and IL-6 of 5.4 ± 2.9 pg/mL, suggesting immune cell cytokine release in response to exercise. Intracellular PBMC p-STAT3 to total STAT3 ratio increased from pre to 4 h. Circulating monocytes are responsive to increased serum IL-6 suggesting a negative feedback loop via STAT3 signaling.
authors.affiliation: Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa.|Division of Endocrinology, Department of Medicine, Stellenbosch University, Tygerberg, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: van de Vyver
authors.affiliation: Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa.|Central Analytical Facility, Stellenbosch University, Stellenbosch, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: Engelbrecht
authors.affiliation: Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa.
authors.forename: C
authors.initials: C
authors.lastname: Smith
authors.affiliation: Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa.
authors.forename: K H
authors.initials: KH
authors.lastname: Myburgh
mesh_terms: D003402:Creatine Kinase / Q000097:blood; D005080:Exercise Test; D005221:Fatigue / Q000097:blood; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D009000:Monocytes / Q000378:metabolism*; D063806:Myalgia / Q000097:blood; D009504:Neutrophils / Q000378:metabolism*; D009195:Peroxidase / Q000097:blood; D010766:Phosphorylation; D005082:Physical Exertion / Q000276:immunology*; D012420:Running / Q000502:physiology*; D050796:STAT3 Transcription Factor / Q000097:blood; D015398:Signal Transduction; D000071223:Suppressor of Cytokine Signaling 3 Protein / Q000097:blood; D055815:Young Adult
chemical_list: D015850:Interleukin-6; C106644:SOCS3 protein, human; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D000071223:Suppressor of Cytokine Signaling 3 Protein; D016753:Interleukin-10; D009195:Peroxidase; D003402:Creatine Kinase; D020780:Matrix Metalloproteinase 9
keywords: Cytokines; PBMC; exercise; inflammation; innate immune system