口腔疾病防治 (May 2018)

Effects of inflammatory microenvironment mediated by macrophage on the proliferation and osteogenic differ⁃ entiation of periodontal ligament cells

  • ZHENG Xiumei,
  • HUANG Wenxia

DOI
https://doi.org/10.12016/j.issn.2096⁃1456.2018.05.004
Journal volume & issue
Vol. 26, no. 5
pp. 297 – 303

Abstract

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Objective The present study investigated the effects of the inflammatory microenvironment mediated by macrophages on the proliferation and osteogenic differentiation of periodontal ligament cells (PDLCs). Methods Conditioned medium containing inflammatory factors was collected following macrophage activation with 1 μg/mL lipo⁃ polysaccharide (LPS). PDLCs were isolated from healthy teeth and cultured in conditioned medium (LPS⁃CM group) or normal medium (control group), and the proliferation of PDLCs was detected using the MTT assay. The cells were cocul⁃ tured with an osteogenic inducer for 3 d and 7 d, and the alkaline phosphatase (ALP) activity of PDLCs was detected us⁃ing an ALP kit. The mRNA expression levels of runt⁃related transcription factor 2 (RUNX2), osteocalcin (OCN), and col⁃ lagen I (COL⁃I) were detected using real⁃time PCR, and the protein levels of RUNX2, OCN, and COL⁃I were detected using Western blotting. Mineralization nodules were observed using Alizarin red staining after osteoinduction for 14 d. Results The OD value of PDLCs in the LPS⁃CM group was lower than that in the control group (P < 0.05). The mRNA levels of RUNX2, OCN, and COL⁃I in the LPS⁃CM group were lower than those in the control group (P < 0.05). In addi⁃ tion to the OCN 3 d group (t = 2.75, P = 0.056), the protein expression of RUNX2, OCN, and COL⁃I in the LPS⁃CM group was lower than that in the control group (P < 0.05). However, the ALP activity of the LPS⁃CM group was higher than that of the control group, which was 1.58⁃fold greater (t = 5.91, P = 0.030) at 3 d and 1.29⁃fold greater (t = 6.01, P = 0.046) at 7 d. The number of calcified nodules in the LPS⁃CM group was significantly less than that in the control group (t = 8.63, P = 0.048). Conclusion The inflammatory microenvironment mediated by macrophages may inhibit the proliferation and osteogenic differentiation of PDLCs.

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