title: Organotypic Cultures of Intervertebral Disc Cells: Responses to Growth Factors and Signaling Pathways Involved.
abstract: Intervertebral disc (IVD) degeneration is strongly associated with low back pain, a major cause of disability worldwide. An in-depth understanding of IVD cell physiology is required for the design of novel regenerative therapies. Accordingly, aim of this work was the study of IVD cell responses to mitogenic growth factors in a three-dimensional (3D) organotypic milieu, comprising characteristic molecules of IVD's extracellular matrix. In particular, annulus fibrosus (AF) cells were cultured inside collagen type-I gels, while nucleus pulposus (NP) cells in chondroitin sulfate A (CSA) supplemented collagen gels, and the effects of Platelet-Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF), and Insulin-Like Growth Factor-I (IGF-I) were assessed. All three growth factors stimulated DNA synthesis in both AF and NP 3D cell cultures, with potencies similar to those observed previously in monolayers. CSA supplementation inhibited basal DNA synthesis rates, without affecting the response to growth factors. ERK and Akt were found to be phosphorylated following growth factor stimulation. Blockade of these two signaling pathways using pharmacologic inhibitors significantly, though not completely, inhibited growth factor-induced DNA synthesis. The proposed culture systems may prove useful for further in vitro studies aiming at future interventions for IVD regeneration.
authors.affiliation: Laboratory of Cell Proliferation & Ageing, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 153 10 Athens, Greece.
authors.forename: Harris
authors.initials: H
authors.lastname: Pratsinis
authors.affiliation: Laboratory of Cell Proliferation & Ageing, Institute of Biosciences & Applications, National Centre for Scientific Research "Demokritos", 153 10 Athens, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Kletsas
mesh_terms: D000818:Animals; D002417:Cattle; D002809:Chondroitin Sulfates / Q000008:administration & dosage; D003094:Collagen / Q000008:administration & dosage; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000378:metabolism; D007403:Intervertebral Disc / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000188:drug therapy / Q000378:metabolism*; D017116:Low Back Pain / Q000188:drug therapy / Q000378:metabolism*; D009924:Organ Culture Techniques; D010982:Platelet-Derived Growth Factor / Q000008:administration & dosage; D044968:Regenerative Medicine; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D010982:Platelet-Derived Growth Factor; D016222:Fibroblast Growth Factor 2; D007334:Insulin-Like Growth Factor I; D002809:Chondroitin Sulfates; D003094:Collagen; D004247:DNA