Presentation: Differential Proteome of Mesenchymal Stem Cells from Osteoarthritis Patients (2007)

847 Differential Proteome of Mesenchymal Stem Cells from Osteoarthritis Patients

OBJECTIVE: Osteoarthritis (OA) is the most prevalent rheumatic disease and has important social and economic implications. OA has long been regarded as an imbalance between destructive and reparative processes driving to degeneration of the articular cartilage with associated subchondral bone changes. Adult mesenchymal stem cells (MSCs) are multipotent cells capable to differentiate to various tissue types including bone and cartilage. Bone marrow may serve as a reservoir for stem cells populations; these stem cells, in situations of extensive tissue damage, are mobilized and migrate to the site of injury contributing widely to local tissue repair.
PURPOSE: To characterize the differential proteome of bone marrow MSCs from OA patients.
METHODS: MSCs protein extracts were prepared from bone marrow aspirates obtained from 6 patients undergoing joint replacement as a result of OA and from 6 healthy donors, without special radiographic signs of OA, in the surgery for the subcapital fracture of the hip. Samples were then analyzed by 2D gels using the DIGE approach. Gel image analysis was performed using the DeCyder Differential Analysis Software Release 6.5 and statistical module EDA 1.0 (GE Healthcare). Protein spots corresponding to statistically significant expression differences were excised from the gels and submitted to tryptic digestion, and the resulting peptides were mass analyzed using an Ultraflex MALDI-TOF/TOF mass spectrometer (Bruker-Daltonics). Protein identification was achieved through database searching with MALDI MS and MS/MS data.
RESULTS: Around 2000 spots were detected in each gel. We found thirty-seven proteins that were differentially expressed, allowing the correct classification of each condition into its corresponding group. Most differential proteins were related to cytoskeleton/motility (n=12, 32%) and metabolic enzymes (n=13, 36%). Interestingly, most proteins related to cytoskeleton/motility were down-regulated (n=10, 83%) in OA patients, representing 45% of down-regulated proteins. Moreover, a high percentage of metabolic enzymes were up-regulated (n=8, 62%) on MSCs of OA patients and their main location was in lysosome/cytoplasm (n=7, 54%).
CONCLUSIONS: The differential proteome from bone marrow MSCs is characterized by diminished cytoskeleton/motility protein levels together with augmented metabolic enzyme levels. Further studies are necessary to assess whether these changes arise from the disregulated reparative processes related to OA.

  R. Rollín Toledo, FIS 04/1698 and Fundacion MM, 2; J. López, None; E. Camafeita, None; E. Calvo, None; F. Marco, None; B. Fernández-Gutiérrez, None.