OBJECTIVETo investigate the expression pattern of FHL2, which is an intracellular signaling transcription molecule during mineralization in cultured human periodontal ligament cells (hPDLCs) in vitro.

METHODShPDLCs were cultured in vitro. Test group was cultured with mineral induction media while control group without induction media. 0, 14, 28 days after culture, alizarin red staining was used to measure the mineral nodules formation. Immunocytochemistry was used to examine the expression of FHL2 protein 0 day and 14 days after mineral induction. Meanwhile, mRNA expression level of FHL2 was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) on the 0, 14, 28 days after induction.

RESULTS14 and 28 days after cultivation, mineral nodules formed and were stained positively with alizarin red staining in test group while no mineral nodule formed in control group. Immunocytochemical results indicated that hPDLCs in test group expressed FHL2 positively. According to RT-PCR results, 14 and 28 days after mineral induction, the expression levels of FHL2 both increased significantly when compared with 0 day (P<0.01), and the expression level at 14 days was 1.4 folds of 0 day.

CONCLUSIONFHL2 protein is found to be involved in the in vitro mineralization of hPDLCs. FHL2 protein may play a role in the differentiation and mineralization of hPDLCs.