title: Therapeutic progenitor cell application for tissue regeneration: Analyzing the impact of toll-like receptor signaling on c-kit+cell migration following ischemia-reperfusion injury in vivo.
abstract: Toll-like-receptor (TLR) mediated immune response has been shown to regulate myocardial damage following cardiac ischemia-reperfusion (IR). It has not been described conclusively so far whether migration of therapeutically applied progenitor cells following an IR event depends on TLR-signaling.
  
  
  
  In vivo migratory capacity murine c-kit+cells following IR injury was quantified by intravital fluorescence microscopy, utilizing the mouse cremaster muscle model and analyzing early (rolling) and late (adhesion) c-kit+cell interaction with the local endothelium. The role of TLR-2 and TLR-4, as well as MyD88 and TRIF was analyzed by applying specific knock-out models.
  
  
  
  A sequence of 15min ischemia followed by 15min of reperfusion induced firm endothelial c-kit+cell adhesion (5.6±1.3cells/mm2in Control vs. 30.2±10.1cells/mm2in IR, p<0.05). Knock-out of TLR-2 and TLR-4 diminished both IR induced early c-kit+cell-endothelial cell interactions (67.6±2.3% c-kit+cell rolling in IR vs. 46.3±4.8% c-kit+cell rolling in IR-TLR-2-ko vs. 45.3±4.8% c-kit+cell rolling in IR-TLR-4-ko, p<0.05) as well as firm endothelial c-kit+cell adhesion (30.2±10.1cells/mm2in IR vs. 16.3±3.9cells/mm2in IR-TLR-2-ko vs. 14.5±4.4cells/mm2in IR-TLR-4-ko, p<0.05). Adaptor protein knock-out resulted in a significantly decreased firm endothelial c-kit+cell adhesion only in MyD88 knock-out but not in TRIF knock-out (9.2±2.2cells/mm2in IR-MyD88-ko vs. 30.1±9.9cells/mm2in IR-WT, p<0.05).
  
  
  
  Artificially applied c-kit+cells interact with the target organ endothelium following IR injury. This interaction seems to depend on TLR-MyD88 signaling. Therapeutic blockade of TLR signaling for anti-inflammatory purposes might interfere with regenerative cell-based therapy protocols.
authors.affiliation: Department of Cardiac Surgery, University Heart Center Rostock, Rostock, Germany. Electronic address: peter.donndorf@med.uni-rostock.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Donndorf
authors.affiliation: Department of Cardiac Surgery, University Heart Center Rostock, Rostock, Germany.
authors.forename: Saifullah
authors.initials: S
authors.lastname: Abubaker
authors.affiliation: Institute of Experimental Surgery, University of Rostock, Rostock, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vollmar
authors.affiliation: Department of Cardiac Surgery, University Heart Center Rostock, Rostock, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Rimmbach
authors.affiliation: Department of Cardiac Surgery, University Heart Center Rostock, Rostock, Germany.
authors.forename: Gustav
authors.initials: G
authors.lastname: Steinhoff
authors.affiliation: Department of Cardiac Surgery, University Heart Center Rostock, Rostock, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kaminski
mesh_terms: D000009:Abdominal Muscles / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology; D033942:Adaptor Proteins, Vesicular Transport / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D002478:Cells, Cultured; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D020022:Genetic Predisposition to Disease; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D012038:Regeneration; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000378:metabolism*; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D053594:Myeloid Differentiation Factor 88; D019009:Proto-Oncogene Proteins c-kit; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; C507780:Myd88 protein, mouse; C476286:Ticam1 protein, mouse; C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse
keywords: Cremaster muscle; Ischemia-reperfusion; Migration; Progenitor cell