[Biologic effects of advanced oxidative protein products on the human gingival fibroblasts]

To investigate the effects of advanced oxidative protein products (AOPP) on the proliferation, apoptosis and matrix metalloproteinase-1 (MMP-1) synthesis of the human gingival fibroblast (HGF). To explore the possible mechanism of the periodontal destruction acceleration in diabetes through AOPP-mediated oxidative stress.

HGF were isolated by both tissue explant cultivation technique and enzyme digestion method. The culture media with 5, 50, 100 mg/L AOPP-HAS were added into each experimental group, but the culture media in the control group didn't contain AOPP-HAS. MTT colorimetric assay and ELISA were used to measure the changes of HGF proliferation and the levels of MMP-1 protein from HGF at different time periods, respectively. Seventy-two hours after co-culture with 50 mg/L AOPP-HSA, cell apoptosis was detected by flow cytometry with Annexin V/PI staining.

Compared to the control group, the growth inhibition rate of HGF in 5, 50, 100 mg/L AOPP-HSA group was significantly different (P < 0.05). The peak value appeared at 48 hours of co-culture [(19.01 +/- 6.28)%, (30.48 +/- 5.75)%, (39.75 +/- 4.60)%, respectively]. There was a dose-dependent relationship between the growth inhibition rate and AOPP-HSA. No significant difference was detected on the apoptotic level between experimental group and the control (P > 0.05). The MMP-1 synthesis in 0.5, 5, 50, 100 mg/L AOPP-HAS group [(55.61 +/- 1.06), (65.78 +/- 4.04), (79.24 +/- 3.09), (89.76 +/- 28.88) mg/L, respectively] was significantly higher than that in the control [(34.90 +/- 3.15) mg/L] after 72 hours co-culture (P < 0.05). There was a dose-dependent relationship between MMP-1 and AOPP-HSA.

AOPP may inhibit the proliferation of HGF and such effect was not achieved through apoptosis. AOPP may increase collagen degradation by promoting MMP-1 synthesis and thus may accelerate periodontal destruction process in diabetes.