title: Differential gene expression of human chondrocytes cultured under short-term altered gravity conditions during parabolic flight maneuvers.
abstract: BACKGROUND
  Chondrocytes are the main cellular component of articular cartilage. In healthy tissue, they are embedded in a strong but elastic extracelluar matrix providing resistance against mechanical forces and friction for the joints. Osteoarthritic cartilage, however, disrupted by heavy strain, has only very limited potential to heal. One future possibility to replace damaged cartilage might be the scaffold-free growth of chondrocytes in microgravity to form 3D aggregates.
  
  
  RESULTS
  To prepare for this, we have conducted experiments during the 20th DLR parabolic flight campaign, where we fixed the cells after the first (1P) and the 31st parabola (31P). Furthermore, we subjected chondrocytes to isolated vibration and hypergravity conditions. Microarray and quantitative real time PCR analyses revealed that hypergravity regulated genes connected to cartilage integrity (BMP4, MMP3, MMP10, EDN1, WNT5A, BIRC3). Vibration was clearly detrimental to cartilage (upregulated inflammatory IL6 and IL8, downregulated growth factors EGF, VEGF, FGF17). The viability of the cells was not affected by the parabolic flight, but showed a significantly increased expression of anti-apoptotic genes after 31 parabolas. The IL-6 release of chondrocytes cultured under conditions of vibration was not changed, but hypergravity (1.8 g) induced a clear elevation of IL-6 protein in the supernatant compared with corresponding control samples.
  
  
  CONCLUSIONS
  Taken together, this study provided new insights into the growth behavior of chondrocytes under short-term microgravity.
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. markus.wehland@med.ovgu.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Wehland
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. ganna.aleshcheva@med.ovgu.de.
authors.forename: Ganna
authors.initials: G
authors.lastname: Aleshcheva
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, 13092, Berlin, Germany. heschulz@mdc-berlin.de.|University of Cologne, Cologne Center for Genomics (CCG), 50931, Cologne, Germany. heschulz@mdc-berlin.de.
authors.forename: Herbert
authors.initials: H
authors.lastname: Schulz
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, 13092, Berlin, Germany. ksaar@mdc-berlin.de.
authors.forename: Katrin
authors.initials: K
authors.lastname: Saar
authors.affiliation: Max-Delbrück-Center for Molecular Medicine, 13092, Berlin, Germany. nhuebner@mdc-berlin.de.
authors.forename: Norbert
authors.initials: N
authors.lastname: Hübner
authors.affiliation: DLR German Aerospace Center, Biomedical Research, Gravitational Biology, 51147, Köln, Germany. ruth.hemmersbach@dlr.de.
authors.forename: Ruth
authors.initials: R
authors.lastname: Hemmersbach
authors.affiliation: Institute for Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, Gravitational Biology Group, 53115, Bonn, Germany. mbraun@uni-bonn.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Braun
authors.affiliation: Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000, Aarhus C, Denmark. xm@biomed.au.dk.
authors.forename: Xiao
authors.initials: X
authors.lastname: Ma
authors.affiliation: German Aerospace Center (DLR), Institute of Aerospace Medicine, Biomedical Research, 51147, Köln, Germany. timo.frett@dlr.de.
authors.forename: Timo
authors.initials: T
authors.lastname: Frett
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. elisabeth.warnke@med.ovgu.de.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Warnke
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. stefan.riwaldt@med.ovgu.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Riwaldt
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. jessica.pietsch@med.ovgu.de.
authors.forename: Jessica
authors.initials: J
authors.lastname: Pietsch
authors.affiliation: Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000, Aarhus C, Denmark. corydon@biomed.au.dk.
authors.forename: Thomas Juhl
authors.initials: TJ
authors.lastname: Corydon
authors.affiliation: Clinic for Plastic, Aesthetic and Hand Surgery, Otto-von-Guericke University, 39120, Magdeburg, Germany. manfred.infanger@med.ovgu.de.
authors.forename: Manfred
authors.initials: M
authors.lastname: Infanger
authors.affiliation: Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000, Aarhus C, Denmark. dgg@biomed.au.dk.
authors.forename: Daniela
authors.initials: D
authors.lastname: Grimm
mesh_terms: D001359:Aviation; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D014893:Weightlessness