Functional analyses of TSP1 in mineralization by osteoblastic cells with Silencer Select siRNA

Akemichi Ueno^*, Takayuki Kumamoto*, Shigeru Oshio*, Kikuji Yamashita**

Department of Hygiene Chemistry, School of Pharmaceutical Sciences, Ohu University*

Department of Oral and Maxillofacial Anatomy, Institute of Health Bioscience, University of Tokushima Graduate School**

TSP1 increases up to the early stage of osteoblastic differentiation, but not found in mineralized matrix. To clarify the role of TSP1 in the mineralization process, we transfected Silencer Select Pre-designed siRNA during plating of MC3T3-E1 cells and compared with the effects of continuous exposure of S-oligo deoxyribonucleotides after confluency. The specific knockdown of TSP1 message by siRNA did not affect the cell adhesion and proliferation, and promoted and/or accelerated matrix mineralization by MC3T3-E1 cells like S-oligos. On the other hand, over-expression of TSP1 retarded and inhibited mineralization. These results with EM observation suggest that TSP1 influences the level, structure, and function of type I collagen.