title: Intervertebral disc regeneration: influence of growth factors on differentiation of human mesenchymal stem cells (hMSC).
abstract: BACKGROUND
  One common cause of disability in modern society is low back pain. The main reason for this pain is the degeneration of the intervertebral disc (IVD), particularly of the nucleus pulposus (NP). For the early degeneration stage, a cell-based therapy could constitute a minimally invasive method of treatment. Therefore, adequate cells are needed. As the usage of NP cells is limited because of their insufficient amount or vitality, a promising alternative is the application of human mesenchymal stem cells (hMSCs)
  
  
  OBJECTIVE
  To investigate the potential of various growth factors to induce the differentiation of hMSCs into NP cells and thereby to obtain an alternative cell source for the treatment of IVD degeneration.
  
  
  METHODS
  hMSC-TERT were cultivated three-dimensionally in a hydrogel for 21 days to form NP cells. Cell survival and proliferation were determined using SybrGreen/propidium iodide double staining and the WST-test. To investigate the ability of several growth factors to differentiate hMSCs into NP cells, fluorescence immunostaining of NP-specific marker proteins (e.g., chondroadherin (CHAD) and the recently discovered cytokeratin 19) were performed.
  
  
  RESULTS
  Following the procedure described above, cells are able to maintain their viability and proliferation capacity throughout the cultivation time. By using a previously established immunofluorescence protocol, we were able to indicate the ability of three different growth factors for differentiating hMSCs into NP-like cells.
  
  
  CONCLUSIONS
  The expression of several marker proteins in all differentiation experiments indicates the ability of IGF-1, FGF-2 and PDGF-BB to differentiate hMSCs into NP-like cells apart from the usually applied TGF-beta3. Furthermore, our findings preclude the application of Cytokeratin 19 as a specific marker protein for NP cells. Further experiments have to be done to find real specific NP marker proteins to indisputably verify the differentiation of hMSCs into NP cells. If so, application of these three growth factors would possibly be an option to obtain sufficient NP cells for minimally invasive IVD regeneration.
authors.affiliation: Institute of Biopharmaceutical Technology, University of Applied Sciences Giessen-Friedberg, Giessen - Germany. franziska.ehlicke@tg.fh-giessen.de
authors.forename: Franziska
authors.initials: F
authors.lastname: Ehlicke
authors.forename: Denise
authors.initials: D
authors.lastname: Freimark
authors.forename: Birthe
authors.initials: B
authors.lastname: Heil
authors.forename: Adriaan
authors.initials: A
authors.lastname: Dorresteijn
authors.forename: Peter
authors.initials: P
authors.lastname: Czermak
mesh_terms: D000943:Antigens, Differentiation / Q000096:biosynthesis; D000077214:Becaplermin; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D020219:Chondrogenesis / Q000502:physiology; D018920:Coculture Techniques; D017077:Culture Media, Conditioned / Q000737:chemistry; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006801:Humans; D020100:Hydrogels; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology* / Q000627:therapeutic use; D007403:Intervertebral Disc / Q000166:cytology; D055959:Intervertebral Disc Degeneration / Q000628:therapy*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins / Q000494:pharmacology*; D012038:Regeneration / Q000502:physiology; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D000943:Antigens, Differentiation; D017077:Culture Media, Conditioned; D020100:Hydrogels; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D011994:Recombinant Proteins; D016222:Fibroblast Growth Factor 2; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I