Depletion of SHANK2 inhibited the osteo/dentinogenic differentiation potentials of stem cells from apical papilla

Lijia Guo¹, Luyuan Jin¹, Juan Du^1,2, Chunmei Zhang¹, Zhipeng Fan² and Songlin Wang<sup>1,3

1</sup>Molecular Laboratory for Gene Therapy and Tooth Regeneration, ²Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology and ³Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing, China

Offprint requests to: Songlin Wang, D.D.S., Ph.D., Capital Medical University School of Stomatology, Tian Tan Xi Li No.4, Beijing 100050, China. e-mail: slwang@ccmu.edu.cn; or Zhipeng Fan, D.D.S., Ph.D., Laboratory of Molecular Signaling and Stem Cells Therapy, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing 100050, China. e-mail: zpfan@ccmu.edu.cn

Summary. The aim of this study was to investigate the biological function of SHANK2 on the osteo/ dentinogenic differentiation potentials of human stem cells from apical papilla (SCAPs). Real-time RT-PCR was used to detect the expression of SHANK2 in human mesenchymal stem cells (MSCs). Small hairpin RNA (shRNA) was used to knockdown the SHANK2 in SCAPs. The knockdown efficiency was determined by real-time RT-PCR and Western Blot. The in vitro osteo/dentinogenic differentiation potentials of SCAPs were investigated using ALP staining, ALP activity, alizarin red staining, quantitative calcium, the expression levels of DSPP, DMP1, RUNX2 and OSX. In vivo transplantation experiments in immunocompromised mice were used to evaluate the capacity of SCAPs to form bone/dentine-like structure. SHANK2 was highly expressed in dental tissue-derived MSCs compared with cells of other origins. Silencing of SHANK2 inhibited the ALP activity, mineralization, and the expressions of DSPP, DMP1, RUNX2 and OSX in SCAPs. Furthermore, in vivo transplantation experiments indicated that knock-down of SHANK2 in SCAPs generated less bone/dentin-like mineralized tissue compared with the control group. The present study demonstrated that depletion of SHANK2 inhibited the osteo/dentinogenic differentiation potentials in SCAPs, explored the new function of SHANK2, and provided useful information to elucidate the molecular mechanism underlying directed differentiation in dental tissue-derived MSCs. Histol Histopathol 32, 471-479 (2017)

Key words: SHANK2, Osteo/dentinogenic differentiation, Stem Cells, Apical Papilla (SCAPs)

DOI: 10.14670/HH-11-812