Abstract: Abstract: Objective Study the role of Tmed2 in murine pre-osteoblast proliferation. Methods 1. Over-express and knock down Tmed2, and the proliferation rate of MC3T3-E1 cell was then detected. 2. MC3T3-E1 cells were treated with β-Estradiol, cell number was then counted and the mRNA level of Tmed2 was analyzed. Quantitative real-time PCR was used to measure the mRNA level, MTS assay was used to assess the cell proliferation rate, flow cytometry was used to figure out the cell cycle distribution, and the protein level was evaluated by Western blot. Results Over-expression of Tmed2 accelerated MC3T3-E1 cell proliferation, and the proportion of cells in S phase markedly increased compared. The expression of Cyclin A also increased. On the contrary, Knockdown of Tmed2 decelerated MC3T3-E1 cell proliferation. In β-Estradiol promoted MC3T3-E1 proliferation, the mRNA level of Tmed2 remarkably increased. Conclusion Tmed2 accelerates murine pre-osteoblast MC3T3-E1 proliferation through up-regulating Cyclin A expression and therefore increasing the proportion of cells in S phase. In addition, the expression of Tmed2 is regulated by β-Estradiol, indicating that Tmed2 is possibly involved in the process of MC3T3-E1 proliferation promoted by β-Estradiol.

Key words: Tmed2, MC3T3-E1 cell, cell proliferation, β-Estradiol