Publication
Degeneration of the intervertebral disc (IVD) is thought to be one main factor in the development of back pain. It is not a symptom by itself but can lead to painful pathological conditions. Current treatments aim at relieving pain by conservative care, medications or surgical removal of the painful part of the disc but do not treat the causes. Disc degeneration is a progressive process which begins in the center of the disc by the loss of water due to impaired cell activity. Our hypothesis is that regeneration of the disc at the first stages of degeneration is likely to delay the progression and the need for surgery. Regeneration could be achieved by a cell-based therapy, which would bring active matrix producing and/or growth factor delivering cells. The up-scaling from bench-side to clinic for a cell therapy is limited due to safety and consistency matters. Thus, the choice of cell-type is of utmost importance to assure consistent efficacy and safety of a therapeutic application. The aim of this work was to characterize human fetal cells isolated from fetal cartilaginous tissues regarding their potential for the correction of IVD degeneration. In a first step and first chapter, a methodology for creating consistent and safe fetal cell banks from only one single tissue donation was developed. This method was illustrated by the example of fetal skin cells, which dedicated cell banks have already been tested in clinical trials. Secondly, in the second chapter, the isolation and chondrogenic potential of fetal spine cells was presented. Fetal cells were isolated from spine units (2 IVDs and 1 vertebra) from 5 donors aged from 12 to 16 weeks of gestation and amplified in monolayer to establish dedicated and consistent cell banks. Alginate bead cultures of fetal spine cells showed heterogenous matrix synthesis ability. Two fetal cell donors (14 and 15 weeks of gestation), showed good aggrecan and type II collagen production with very low type X collagen production. Mesenchymal stem cells (MSCs) can be differentiated into several phenotypes and show good regeneration capacity. Fetal cells also show good regeneration property but there is little information concerning their plasticity. Thus, in chapter three, the plasticity of fetal spine cells was investigated and compared it to that of MSCs. Cells isolated from fetal articular cartilage were also investigated as they also represent a potential source of fetal cartilaginous cells. Similarly to MSCs, fetal cells from both origins were positive for surface markers CD44, CD73, CD105 and CD166 and were negative for CD34 and CD45. Fetal cells exhibited much lower adipogenic and osteogenic differentiation levels than MSCs. As expected, fetal cells showed high chondrogenic differentiation, showed by aggrecan and type II collagen production, in TGF-β3 stimulated high cell mass density system. A mild level of type X collagen was detected in fetal spine cell pellets, whereas fetal cartilage cell pellets were h