title: Chronic endurance exercise affects paracrine action of CD31+ and CD34+ cells on endothelial tube formation.
abstract: We aimed to determine if chronic endurance-exercise habits affected redox status and paracrine function of CD34(+) and CD34(-)/CD31(+) circulating angiogenic cells (CACs). Subjects were healthy, nonsmoking men and women aged 18-35 yr and categorized by chronic physical activity habits. Blood was drawn from each subject for isolation and culture of CD34(+) and CD34(-)/CD31(+) CACs. No differences in redox status were found in any group across either cell type. Conditioned media (CM) was generated from the cultured CACs and used in an in vitro human umbilical vein endothelial cell-based tube assay. CM from CD34(+) cells from inactive individuals resulted in tube structures that were 29% shorter in length (P < 0.05) and 45% less complex (P < 0.05) than the endurance-trained group. CD34(-)/CD31(+) CM from inactive subjects resulted in tube structures that were 26% shorter in length (P < 0.05) and 42% less complex (P < 0.05) than endurance-trained individuals. Proteomics analyses identified S100A8 and S100A9 in the CM. S100A9 levels were 103% higher (P < 0.05) and S100A8 was 97% higher in the CD34(-)/CD31(+) CM of inactive subjects compared with their endurance-trained counterparts with no significant differences in either protein in the CM of CD34(+) CACs as a function of training status. Recombinant S100A8/A9 treatment at concentrations detected in inactive subjects' CD34(-)/CD31(+) CAC CM also reduced tube formation (P < 0.05). These findings are the first, to our knowledge, to demonstrate a differential paracrine role in CD34(+) and CD34(-)/CD31(+) CACs on tube formation as a function of chronic physical activity habits and identifies a differential secretion of S100A9 by CD34(-)/CD31(+) CACs due to habitual exercise.
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Rian Q
authors.initials: RQ
authors.lastname: Landers-Ramos
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Sapp
authors.affiliation: Department of Kinesiology, University of Georgia, Athens, Georgia.
authors.forename: Nathan T
authors.initials: NT
authors.lastname: Jenkins
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Murphy
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Lucile
authors.initials: L
authors.lastname: Cancre
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Eva R
authors.initials: ER
authors.lastname: Chin
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and.
authors.forename: Espen E
authors.initials: EE
authors.lastname: Spangenburg
authors.affiliation: Department of Kinesiology, School of Public Health, University of Maryland College Park, College Park, Maryland; and hagberg@umd.edu.
authors.forename: James M
authors.initials: JM
authors.lastname: Hagberg
mesh_terms: D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000235:genetics / Q000378:metabolism*; D016022:Case-Control Studies; D002478:Cells, Cultured; D066026:Endothelial Progenitor Cells / Q000166:cytology / Q000378:metabolism*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D018919:Neovascularization, Physiologic; D019899:Paracrine Communication; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D009418:S100 Proteins
keywords: angiogenesis; circulating angiogenic cell; exercise; paracrine; physical activity