Effect of overexpression of GRN on the proliferation and osteogenic capacity of human periodontal cells.

A human periodontal ligament cell line stably overexpressing the granulin precursor gene (GRN) was established through lentiviral mediation to explore the effects of GRN on the proliferation and osteogenic capacity of human periodontal ligament cells (hPDLCs). In the present study, a homologous recombinant lentiviral plasmid, pLV-GRN, was constructed and transfected into the hPDLCs. The expression levels of GRN and progranulin were assessed using reverse transcription-quantitative (RT-q)PCR and western blotting and the effect of GRN on the proliferative capacity was determined using the MTT assay. The osteogenic capacity of human periodontal cells overexpressing GRN was evaluated. The results showed that successful construction and transfection of the homologous recombinant lentiviral plasmid pLV-GRN led to the development of a stable periodontal cell line overexpressing GRN. The MTT assay results revealed an enhanced proliferative capacity in the pLV-GRN group compared with that in the hPDLCs and pLV-puro groups (P<0.05). Alizarin red staining and alkaline phosphatase (ALP) activity assays indicated a significantly increased osteogenic capacity in the pLV-GRN group compared with the hPDLCs and pLV-puro groups (P<0.01). RT-qPCR demonstrated strong expression of the osteogenic genes ALP, runt-related transcription factor 2 (Runx2) and osteopontin (OPN) in the periodontal cells of the pLV-GRN group (P<0.05), whereas western blotting results corroborated the high expression of the osteogenic genes Runx-2 and OPN in the periodontal cells of the pLV-GRN group (P<0.05). In summary, the overexpression of GRN significantly enhanced the proliferation and osteogenic capacity of hPDLCs. These findings provide an experimental foundation for periodontal tissue regeneration.