Analyses Of Cd90 Role In The Growth, Osteogenic Differentiation And Morphology, Immunogenic Property Of Human Mesenchymal Stem Cells (Msc)

MSCs are isolated from several human tissues and expanded in vitro. These cells promptly differentiate into multiple connective tissue lineages, such as osteoblasts, chondrocytes and adipocytes. Studies showed that human MSC have unique immunological properties: they are not immunogenic, they do not simulate alloreactivity, they scape from T citotoxic and NK cells lysis activity. The imunophenotypic characterization of MSC is positive for expression of cell markers CD90, CD105, CD73, CD117, CD44, CD166, CD29 and STRO-1. This work has as goal the analysis of CD90 glycoprotein role in the morphology, growth, differentiation of dental pulp MSCs, and immunological response of CD90 through the reduction of CD90 expression using RNA interference mechanism. Lentivirus particles were used to create stable MSCs clones expressing shRNA against CD90 and a scramble shRNA control. Clones were isolated via puromycin selection. The reduction of CD90 expression, confirmed in flow cytometry assays, was analysed using FLOJO software. Morphology was analysed using phase contrast optical microscopy and flow citometry. For proliferative rate analyses the number of adherent cells was determined by hemocytometer. For differentiation analyses, cells were induced for osteogenic differentiation and their calcium deposits were stained with Alisarin red. We investigated calcium concentration through Espectometry. We found that a significant decrease in CD90 levels does not affect MSCs immunogenic properties, proliferation, differentiation and morphology. The partial reduction of CD90 expression leads: to a decrease in CD166 and CD44 expression and to an increase in calcium concentration and mineralization when compared to our control cells. This work supported by CNPQ.