[CCN3 regulates the proliferation and apoptosis in periodontal ligament fibroblasts].

Purpose: To investigate the effect of CCN3 on proliferation and apoptosis in periodontal ligament fibroblasts (PDLFs) and related mechanism.

Methods: Recombinant vector pcDNA.3.1-CCN3 was constructed and transfected into human PDLFs to overexpress CCN3. CCN3 siRNA was transfected to inhibit CCN3. Fra-1 siRNA was transfected into the PDLFs with CCN3 inhibition to realize the inhibition of CCN3 and Fra-1 in the meantime. mRNA expressions of CCN3 and Fra-1 were measured by quantitative real-time PCR (qRT-PCR). The protein expressions of CCN3, Fra-1and Bcl-2 were detected by Western blot. Cell growth and viability and proliferation of PDLFs were measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and bromodeoxyuridine (BrdU) assays; Caspase-3 activity was tested by using the available kit. The data were analyzed with SPSS20.0 software package.

Results: The results showed that the mRNA (P<0.05) and protein (P<0.05) expressions of CCN3 were significantly up-regulated in the experimental group of pcDNA.3.1-CCN3 transfection. In addition, the mRNA (P<0.05) and protein (P<0.05) expressions of CCN3 were significantly decreased in the experimental group of CCN3 siRNA transfection. Cell growth (P<0.05) and viability, proliferation (P<0.05) and Bcl-2 (P<0.05) protein expression were increased, while caspase-3 activity (P<0.05) decreased in the PDLFs with CCN3 inhibition. However, CCN3 overexpression exhibited reversed effect. CCN3 overexpression or inhibition could remarkably constrain (P<0.05) or promote (P<0.01) the expression of Fra-1, respectively. Moreover, co-inhibition of CCN3 and Fra-1 could promote apoptosis (P<0.01) and inhibit proliferation (P<0.05) in PDLFs.

Conclusions: The results suggest that inhibition of CCN3 could accelerate proliferation and constrain apoptosis via up-regulating expression of Fra-1 in PDLFs.