eCM (Eur Cell Mater / e Cells & Materials) eCM Open Access Scientific Journal
 ISSN:1473-2262         NLM:100973416 (link)         DOI:10.22203/eCM

2011   Volume No 21 – pages 221-229

Title: The in vitro effects of dexamethasone, insulin and triiodothyronine on degenerative human intervertebral disc cells under normoxic and hypoxic conditions

Author: A Bertolo, L Ettinger, N Aebli, D Haschtmann, M Baur, U Berlemann, SJ Ferguson, JV Stoyanov

Address: Biomedical Laboratories, Swiss Paraplegic Research, G.A.Zaech Strasse 4, CH 6207 Nottwil, Switzerland

E-mail: jivko.stoyanov at paranet.ch

Key Words: Intervertebral disc degeneration, dexamethasone, insulin, triiodothyronine, cartilage, collagen, aggrecan, glycosaminoglycan.

Publication date: February 24th 2011

Abstract: Degeneration of intervertebral discs (IVD) is one of the main causes of back pain and tissue engineering has been proposed as a treatment. Tissue engineering requires the use of highly expensive growth factors, which might, in addition, lack regulatory approval for human use. In an effort to find readily available differentiation factors, we tested three molecules – dexamethasone, triiodothyronine (T3) and insulin – on human IVD cells isolated after surgery, expanded in vitro and transferred into alginate beads. Triplicates containing 40 ng/ml dexamethasone, 10 nM T3 and 10 µg/ml insulin, together with a positive control (10 ng/mL transforming growth factor (TGF)-beta 1), were sampled weekly over six weeks and compared to a negative control. Furthermore, we compared the results to cultures with optimized chondrogenic media and under hypoxic condition (2% O2). Glycosaminoglycan (GAG) determination by Alcian Blue assay and histological staining showed dexamethasone to be more effective than T3 and insulin, but less than TGF-beta1. DNA quantification showed that only dexamethasone stimulated cell proliferation. qPCR demonstrated that TGF-beta1 and the optimized chondrogenic groups increased the expression of collagen type II, while aggrecan was stimulated in cultures containing dexamethasone. Hypoxia increased GAG accumulation, collagen type II and aggrecan expression, but had no effect on or even lowered cell number. In conclusion, dexamethasone is a valuable and cost-effective molecule for chondrogenic and viability induction of IVD cells under normoxic and hypoxic conditions, while insulin and T3 did not show significant differences.

Article download: Pages 221-229 (PDF file)
DOI: 10.22203/eCM.v021a17