Transcriptome profile in the human synovial MSC-aggregates

One of strategies to regenerate cartilage defect is transplantation of mesenchymal stem cells (MSCs). Improvements of therapeutic potential of MSCs are needed to achieve successful cartilage regeneration by transplantation of a limited number of cells. Aggregated culture is a popular method in ES and iPS cells to maintain or enhance their potentials. Here we investigated gene expression profile of aggregated MSCs. 621 genes were up-regulated and 409 genes were down-regulated more than 5-fold in MSC-aggregates compared with the number in MSCs in a monolayer culture. The most up-regulated gene was BMP2, which is one of the genes involved in chondrogenesis. Anti-inflammatory genes were also up-regulated in MSC-aggregates. The microarray data for selected genes were confirmed by real-time PCR. Human synovial MSCs was isolated from synovium of 3 distinct donors. The gene expression profile of MSC-aggregates cultured in hanging drop for 3days was compared with that of MSCs in a monolayer culture.