Inflammation and Repair - Regenerative Medicine - IVD regeneration - current projects (projects)
Elucidating the molecular mechanisms of MSC-nucleus pulposus cell interactions for regeneration of the human intervertebral disc
Low back pain (LBP) is one of the largest socioeconomic problems facing health care systems around the world. One of the largest contributors to LBP is degeneration of the intervertebral disc (IVD). However, the majority of current treatments are aimed at removing the symptoms associated with low back pain, rather than repairing the degenerate IVD. Therefore the host laboratory is aiming to develop a tissue engineering approach to regenerate the NP and restore disc height and function. Due to the unsuitability of degenerate NP cells they have concentrated on the use of autologous human mesenchymal stem cells (MSCs) which they have previously shown can be differentiated to NP-like cells in vitro.
Co-culture systems are a powerful in vitro tool for studying the cellular interactions which may occur during repair and regeneration and thus are important models when investigating potential regenerative cell therapies. Preliminary studies performed by the host laboratory using such systems showed that co-culture of MSCs with NP cells from normal IVD caused MSC differentiation to cells with an NP-like phenotype, while co-culture of MSCs with NP cells from degenerate IVD caused both MSC differentiation to NP-like cells and changes in NP cells from a catabolic to a more anabolic state. This differentiation was only evident when cells were in direct contact, or in very close proximity, suggesting direct cellular interactions were important for differentiation. These data also highlight the possibility that MSCs implanted into the degenerate human IVD may undergo differentiation to NP-like cells. It is therefore important to understand the molecular mechanisms which underlie this induced differentiation, in order to develop cell-based regenerative strategies for repair of the degenerate human IVD.
Using a plethora of cell culture, imaging and molecular biology techniques, the aims of this PhD are to:
1) identify the molecular mechanisms by which NP (normal or degenerate) cells and MSCs interact. This will focus on novel concepts of cell-cell communication, including the formation of nanotubules and microvesicles, as methods of transferring information (cellular components, RNA and particularly miRNA) between cells.
2) identify whether addition of growth factors or cytokines enhances differentiation.
3) identify whether differentiation can occur under environmental conditions which mimic those found in the normal or degenerate IVD; in particular focusing on 3D culture environments and modification of culture conditions to match those in vivo, including low glucose, low pH, low oxygen, presence of catabolic cytokines.
4) test the efficacy of MSC differentiation in an ex vivo model of human IVD degeneration.
Importantly, data obtained from this research regarding the nature of the cell-cell interaction in inducing MSC differentiation to NP-like cells will be pivotal to our understanding prior to translation of potential therapies to clinical application.
Duration of the project
3 years ( September 2009- Sept 2012)
The University of Manchester ORS