title: Alteration of inflammatory response by shock wave therapy leads to reduced calcification of decellularized aortic xenografts in mice†.
abstract: OBJECTIVE
  Tissue-engineered xenografts represent a promising treatment option in heart valve disease. However, inflammatory response leading to graft failure and incomplete in vitro repopulation with recipient cells remain challenging. Shock waves (SWs) were shown to modulate inflammation and to enhance re-epithelialization. We therefore aimed to investigate whether SWs could serve as a feasible adjunct to tissue engineering.
  
  
  METHODS
  Porcine aortic pieces were decellularized using sodium deoxycholate and sodium dodecylsulphate and implanted subcutaneously into C57BL/6 mice (n = 6 per group). The treatment (shock wave therapy, SWT) group received SWs (0.1 mJ/mm(2), 500 impulses, 5 Hz) for modulation of inflammatory response directly after implantation; control animals remained untreated (CTR). Grafts were harvested 72 h and 3 weeks after implantation and analysed for inflammatory cytokines, macrophage infiltration and polarization, osteoclastic activity and calcification. Transmission electron microscopy (TEM) was performed. Endothelial cells (ECs) were treated with SWs and analysed for macrophage regulatory cytokines. In an ex vivo experimental set-up, decellularized porcine aortic valve conduits were reseeded with ECs with and without SWT (0.1 mJ/mm(2), 300 impulses, 3 Hz), fibroblasts as well as peripheral blood mononuclear cells (all human) and tested in a pulsatile flow perfusion system for cell coverage.
  
  
  RESULTS
  Treated ECs showed an increase of macrophage migration inhibitory factor and macrophage inflammatory protein 1β, whereas CD40 ligand and complement component C5/C5a were decreased. Subcutaneously implanted grafts showed increased mRNA levels of tumour necrosis factor α and interleukin 6 in the treatment group. Enhanced repopulation with recipient cells could be observed after SWT. Augmented macrophage infiltration and increased polarization towards M2 macrophages was observed in treated animals. Enhanced recruitment of osteoclastic cells in proximity to calcified tissue was found after SWT. Consequently, SWT resulted in decreased areas of calcification in treated animals. The reseeding experiment revealed that fibroblasts showed the best coverage compared with other cell types. Moreover, SW-treated ECs exhibited enhanced repopulation compared with untreated controls.
  
  
  CONCLUSIONS
  SWs reduce the calcification of subcutaneously implanted decellularized xenografts via the modulation of the acute macrophage-mediated inflammatory response and improves the in vitro repopulation of decellularized grafts. It may therefore serve as a feasible adjunct to heart valve tissue engineering.
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Can
authors.initials: C
authors.lastname: Tepeköylü
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Lobenwein
authors.affiliation: University Hospital for Dermatology and Venerology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Blunder
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Radoslaw
authors.initials: R
authors.lastname: Kozaryn
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Marion
authors.initials: M
authors.lastname: Dietl
authors.affiliation: University Hospital for Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Paul
authors.initials: P
authors.lastname: Ritschl
authors.affiliation: Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Elisabeth J
authors.initials: EJ
authors.lastname: Pechriggl
authors.affiliation: Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Michael J F
authors.initials: MJ
authors.lastname: Blumer
authors.affiliation: Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Mario
authors.initials: M
authors.lastname: Bitsche
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Roland
authors.initials: R
authors.lastname: Schistek
authors.affiliation: University Hospital for Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Katja
authors.initials: K
authors.lastname: Kotsch
authors.affiliation: Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Helga
authors.initials: H
authors.lastname: Fritsch
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Grimm
authors.affiliation: University Hospital for Cardiac Surgery, Medical University of Innsbruck, Innsbruck, Austria johannes.holfeld@i-med.ac.at.
authors.forename: Johannes
authors.initials: J
authors.lastname: Holfeld
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D001021:Aortic Valve / Q000166:cytology / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects; D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology*; D016207:Cytokines / Q000032:analysis; D006349:Heart Valve Diseases; D006350:Heart Valve Prosthesis; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013552:Swine
chemical_list: D016207:Cytokines
keywords: Decellularized xenografts; Heart valve disease; Macrophages; Shock wave therapy; Tissue engineering