Mesenchymal stem/stromal cells (MSCs) are a subset of heterogeneous, non-haematopoietic fibroblast-like cells. Their physiological role is to maintain tissue homeostasis, mainly through proliferation, differentiation, and the release of growth factors and immunomodulators. These unique characteristics make MSCs attractive for regenerative medicine, inflammatory diseases, and cancer treatment. One of the potential diseases for MSC therapy is osteoarthritis (OA), chronic degenerative disease of the joints. The most obvious syndrome of OA is articular cartilage damage resulting from degeneration of the extracellular matrix. Due to the inability of the articular cartilage to regenerate itself after injury, which may be the cause of OA, the use of MSCs for the treatment of articular cartilage is being investigated. In the addition to their differentiation capacity, MSCs also play a role in regulating immune response. MSCs act on immune cells through various immunomodulatory effects mediated by soluble factors or directly via intercellular contacts. The aim of this thesis is to determine the differences in gene expression of immunomodulatory molecules in MSCs obtained from different hip tissues of subjects with and without degenerative hip lesions, to determine if any of these MSCs have a better immunomodulatory potential. Samples were obtained during hip arthroscopy from three tissues of the synovium and the femoral trabecular bone column. Primary MSCs were amplified under in vitro conditions and RNA was isolated from them. Prior to sample analysis, we optimised the quantitative polymerase chain reaction (qPCR) method to measure the expression of 8 genes for immunomodulatory molecules such as indoleamine 2,3-dioxygenase 1 (IDO1), interleukin 1 beta (IL1B), programmed cell death ligand 1 (PDL1), vascular cell adhesion molecule 1 (VCAM1), hepatocyte growth factor (HGF), human leukocyte antigen G (HLA-G), TNF-α-induced protein 6 (TNFAIP6), and interleukin 1 receptor antagonist (IL1RA). Based on optimisation we selected 6 genes for further analysis (PDL1, VCAM1, HGF, HLA-G, TFNAIP6 and IL1RA). The results were then normalised to the selected GAPDH reference gene and compared between patients with and without early OA and between different tissues. Three hypotheses were tested: 1.) gene expression for immunomodulatory molecules differs between MSCs from patients with early OA compared to those without OA, 2.) gene expression for immunomodulatory molecules differs between MSCs from different tissues from patient with early OA and 3.) gene expression for immunomodulatory molecules differs between MSCs from different tissues from patients without OA. Only the first hypothesis was partially confirmed for the HGF gene, while the other two were rejected. The HGF gene is approximately 4 times more highly expressed in MSCs from patient without OA compared to those with early OA, which provides an important basis for further investigation of the immunomodulatory effects of MSCs in OA. Our study did not identify tissue specific MSCs with immunomodulatory potential, probably due to insufficient sample numbers, and we suggest further studies in a larger number of subjects.
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