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Published on: July 8, 2021
[Effect of sonicated extracts of Porphyromonas gingivalis on osteogenic differentiation of mouse osteoblasts]
Jian-ying Zhang1, Shao-jie Yu, Yun Fu
1Department of Periodontology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yet-sen University & Guangdong Provincial Key Laboratory of Stomatology, Guangzhou 510055, China.
Objective:
To investigate the effects of sonicated extracts of Porphyromonas gingivalis (Pg) on osteogenic differentiation of mouse osteoblast cell line MC3T3-E1.
Methods:
PgW83 was cultured under standard anaerobic conditions and extracted by sonication. Mouse osteoblast cell line MC3T3-E1 was cultured with various concentrations of the extraction (0, 10, 100, 1000 mg/L). Western blotting was applied to investigate the expression of osteocalcin (OC), bone sialoprotein (BSP), osteopontin (OPN) and osteonectin (ON). The activity of alkaline phosphatase (ALP) was detected by microplate reader after 14 days. Mineralization nodule formation was measured by alizarin red staining after 21 days.
Results:
Compared with the control group, the extracts of Pg decreased OC and ON expression in a dose-dependent manner (OC relative expression:1.000 ± 0.000,0.852 ± 0.110,0.625 ± 0.451,0.213 ± 0.053), (ON relative expression: 1.000 ± 0.000, 1.035 ± 0.133,0.141 ± 0.023,0.020 ± 0.003) (P < 0.05). The expression of OPN was down-regulated significantly in MC3T3-E1 treated with 1000 mg/L extraction (0.572 ± 0.162) compared with control group, 10 and 100 mg/L (1.000 ± 0.000, 1.029 ± 0.135, 1.199 ± 0.337) (P < 0.05). The expression of BSP remained unchanged when the cells were cultured with or without extraction (BSP relative expression:1.000 ± 0.000,0.831 ± 0.182,0.897 ± 0.115,0.778 ± 0.235) (P > 0.05). Meanwhile, the extracts of Pg decreased ALP activity [control group:(0.0275 ± 0.0014) U/gprot, 10 mg/L: (0.0140 ± 0.0011) U/gprot, 100 mg/L: (0.0057 ± 0.0013) U/gprot, 1000 mg/L: (0.0020 ± 0.0008) U/gprot] (P < 0.05) and reduced mineralization nodule formation.
Conclusions:
The results suggest that Pg may inhibit osteoblasts'osteogenic function by down-regulation of osteogenic differentiation related proteins.
Insights
Sonicated extracts of Porphyromonas gingivalis (Pg) inhibit osteoblast differentiation. Pg extracts reduce key protein expression and mineralization in MC3T3-E1 cells, suggesting a negative impact on bone formation.
Area of Science:
- Cell Biology
- Biochemistry
- Periodontology
Context:
- Porphyromonas gingivalis (Pg) is implicated in periodontitis, a condition affecting bone health.
- Osteoblasts are crucial for bone formation and remodeling.
- Understanding the molecular mechanisms of Pg's impact on osteoblasts is vital.
Purpose:
- To investigate the effects of sonicated Porphyromonas gingivalis (Pg) extracts on the osteogenic differentiation of mouse MC3T3-E1 osteoblast cells.
- To analyze the expression of key osteogenic markers and assess mineralization capacity.
Summary:
- Sonicated Pg extracts were applied to MC3T3-E1 cells at varying concentrations.
- Western blotting revealed dose-dependent decreases in osteocalcin (OC) and osteonectin (ON) expression.
- Osteopontin (OPN) expression was significantly downregulated at high concentrations, while bone sialoprotein (BSP) remained unchanged.
- Alkaline phosphatase (ALP) activity and mineralization nodule formation were significantly reduced by Pg extracts.
Impact:
- Pg extracts inhibit osteogenic differentiation in MC3T3-E1 cells.
- This inhibition occurs through the downregulation of specific osteogenic proteins.
- Findings suggest a potential mechanism by which Pg contributes to bone loss in periodontal disease.
