Objective        To study the effect of IRE1α on the proliferation of human periodontal ligament fibroblasts (hPDLFs).       Methods        The IRE1α full-length eukaryotic expression vectors were constructed and transiently transferred into hPDLFs

and the expression of IRE1α was identified by Western blot analysis. The proliferation of hPDLFs was analyzed by XTT assay

and the changes of cell cycle were detected by flow cytometry (FCM).       Results        Restriction enzyme digestion and gene sequencing identified that the IRE1α recombinant plasmid was successfully constructed

and the correct expression of IRE1α in hPDLFs was detected by

Western blotting. Compared with the control group (tunicamycin)

the XTT results showed that the cell proliferation rate of the IRE1α group increased significantly (P0.01)

and the FCM results showed that the cell proportion increased at S phase and decreased at G

1

phase in the IRE1α group (P0.05).       Conclusion        IRE1α can improve hPDLFs proliferation

and promote hPDLFs from G

1

phase into S phase.