Combining enamel matrix proteins with mechanical stimuli potentiates human periodontal ligament fibroblasts proliferation and periodontium remodeling
Rui Zou1,2,3, Wanting Wan3, Jingjing Li4, Chanyuan Du3, Yijie Wang3, Tian Qian3 and Lin Niu1,3
1Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, 2Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, 3College of Stomatology, Xi'an Jiaotong University, Xi'an and 4Taian City Central Hospital, Taian, Shandong, P.R. China
Offprint requests to: Dr. Lin Niu, College of Stomatology, Xi'an Jiaotong University, Xi'an, 710004, P.R. China. e-mail: niulin@mail.xjtu.edu.cn
Summary. Background. Collagen I (Col-I) and matrix metalloproteinase-1 (MMP-1) have been implicated in the regeneration and remodeling of the periodontium. Studies have shown that enamel matrix proteins (EMPs) and mechanical stimuli can promote the synthesis and degradation, respectively, of Col-I and MMP-1. However, the effects of the combination of EMPs and mechanical stimuli on human periodontal ligament are not known.
Objective. Our aim was to test the combined effects of EMPs and mechanical stimuli on the proliferation of human periodontal ligament fibroblasts (HPDLFs) and Col-I and MMP-1 mRNA expression.
Methods. Primary HPDLFs were isolated using an enzyme digestion method. To select the optimum EMP concentration and the optimum magnitude and loading time of mechanical stimuli, HPDLFs were stimulated with gradient concentration of EMPs (0 µg/mL, 25 µg/mL, 50 µg/mL, 100 µg/mL and 200 µg/mL) and mechanical stimuli (0 kPa, 25 kPa, 50 kPa, 100 kPa, and 200 kPa for 0 h, 3 h, 6 h, 12 h, and 24 h), respectively. The cell proliferative response was tested by the MTT assay. The impact of EMPs combined with mechanical stimuli on Col-I and MMP-1 mRNA expression were measured by reverse transcription polymerase chain reaction.
Results. 100 µg/mL of EMPs and a 50 kPa mechanical stimulus were chosen as the optimum parameters due to the higher proliferation rates than other doses. The combination of 100 µg/mL of EMPs and a 50 kPa mechanical stimulus significantly stimulated HPDLFs proliferation and increased Col-I and MMP-1 expression levels compared with incubation with two factors alone.
Conclusions. We concluded that the combination of EMPs and mechanical stimulus have synergistic effects on cell growth, cell number, collagen turnover, and periodontium remodeling. Histol Histopathol 33, 825-833 (2018)
Key words: Human periodontal ligament fibroblasts, Enamel matrix proteins, Mechanical stimuli, Proliferation, Collagen I, Matrix Metalloproteinase-1
DOI: 10.14670/HH-11-978