title: Ex vivo paracrine properties of cardiac tissue: Effects of chronic heart failure.
abstract: BACKGROUND
  Cardiac regenerative responses are responsive to paracrine factors. We hypothesize that chronic heart failure (HF) in pediatric patients affects cardiac paracrine signaling relevant to resident c-kit(+)cluster of differentiation (CD)34- cardiac stem cells (CSCs).
  
  
  METHODS
  Discarded atrial septum (huAS) and atrial appendages (huAA) from pediatric patients with HF (huAA-HF; n = 10) or without HF (n = 3) were explanted and suspension explant cultured in media. Conditioned media were screened for 120 human factors using unedited monoclonal antibody-based arrays. Significantly expressed (relative chemiluminescence >30 of 100) factors are reported (secretome). Emigrated cells were immunoselected for c-kit and enumerated as CSCs.
  
  
  RESULTS
  After culture Day 7, CSCs emigrate from huAA but not huAS. The huAA secretome during CSC emigration included hepatocyte growth factor (HGF), epithelial cell-derived neutrophil attractant-78 (ENA-78)/chemokine (C-X-C motif) ligand (CXCL) 5, growth-regulated oncogene-α (GRO-α)/CXCL1, and macrophage migration inhibitory factor (MIF), candidate pro-migratory factors not present in the huAS secretome. Survival/proliferation of emigrated CSCs required coculture with cardiac tissue or tissue-conditioned media. Removal of huAA (Day 14) resulted in the loss of all emigrated CSCs (Day 28) and in decreased expression of 13 factors, including HGF, ENA-78/CXCL5, urokinase-type plasminogen activator receptor (uPAR)/CD87, and neutrophil-activating protein-2 (NAP-2)/CXCL7 candidate pro-survival factors. Secretomes of atrial appendages from HF patients have lower expression of 14 factors, including HGF, ENA-78/CXCL5, GRO-α/CXCL1, MIF, NAP-2/CXCL7, uPAR/CD87, and macrophage inflammatory protein-1α compared with AA from patients without HF.
  
  
  CONCLUSIONS
  Suspension explant culturing models paracrine and innate CSC interactions in the heart. In pediatric patients, heart failure has an enduring effect on the ex vivo cardiac-derived secretome, with lower expression of candidate pro-migratory and pro-survival factors for CSCs.
authors.affiliation: Department of Pediatrics, University of Washington/Seattle Children's Research Institute, Seattle, Washington. Electronic address: boucekr@yahoo.com.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Boucek
authors.affiliation: School of Medicine, University of Central Florida, Orlando, Florida.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Steele
authors.affiliation: Johns Hopkins All Children's Heart Institute, St. Petersburg, Florida.
authors.forename: Jeffery P
authors.initials: JP
authors.lastname: Jacobs
authors.affiliation: Department of Pathology, Johns Hopkins All Children's Hospital, St. Petersburg, Florida.
authors.forename: Peter
authors.initials: P
authors.lastname: Steele
authors.affiliation: Johns Hopkins All Children's Heart Institute, St. Petersburg, Florida.
authors.forename: Alfred
authors.initials: A
authors.lastname: Asante-Korang
authors.affiliation: Johns Hopkins All Children's Heart Institute, St. Petersburg, Florida.
authors.forename: James
authors.initials: J
authors.lastname: Quintessenza
authors.affiliation: Congenital Heart Institute of Florida, St. Petersburg, Florida.
authors.forename: Ann
authors.initials: A
authors.lastname: Steele
mesh_terms: D000293:Adolescent; D018952:Antigens, CD34 / Q000378:metabolism; D020517:Atrial Appendage / Q000166:cytology; D054087:Atrial Septum / Q000166:cytology; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation / Q000502:physiology; D002478:Cells, Cultured; D018925:Chemokines / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D017077:Culture Media, Conditioned / Q000494:pharmacology; D016207:Cytokines / Q000502:physiology*; D005260:Female; D006321:Heart / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D007231:Infant, Newborn; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology*; D008297:Male; D019899:Paracrine Communication / Q000502:physiology*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology
chemical_list: D018952:Antigens, CD34; D018925:Chemokines; D017077:Culture Media, Conditioned; D016207:Cytokines; D036341:Intercellular Signaling Peptides and Proteins
keywords: ex vivo paracrine function; explant culture; growth factors; heart failure; stem cell