Changes in Expression of the Membrane Receptors CD14, MHC-II, SR-A, and TLR4 in Tissue-Specific Monocytes/Macrophages Following Porphyromonas gingivalis–LPS Stimulation
The aim of the study was to provide a theoretical foundation for understanding the relationship between periodontal diseases and systemic diseases by examining the inflammatory effect of Porphyromonas gingivalis lipopolysaccharide (LPS) on monocytes/macrophages isolated from tissues distinct from the oral cavity in normal and hyperlipidemic New Zealand white rabbits. Macrophages were isolated from four separate tissues (mononuclear cells from blood, alveolar macrophages, peritoneal macrophages, and Kupffer cells) from both normal and hyperlipidemic New Zealand white rabbits. Cells were either stimulated for 24 h in vitro with P. gingivalis–LPS or Escherichia coli–LPS, or were pre-treated with IL-10 before P. gingivalis–LPS treatment. RNA was isolated and the expression of SR-A, TLR4, CD14, and MHC-II measured by RT-PCR. For MHC-II, the suppression effects of P. gingivalis–LPS were similar to the effects of E. coli–LPS in all macrophages examined. In general, the magnitude of the effects of P. gingivalis–LPS on gene expression was lower than that of E. coli–LPS, and there were differences in the relative membrane receptors between the two, implying that the two LPSs stimulate different responses. IL-10 increased the expression of the defensive receptor SR-A and decreased the expression of CD14, TLR4, and the antigen-presenting molecule MHC-II in all types of macrophages examined, regardless of hyperlipidemic state. These data are consistent with an anti-inflammatory effect of IL-10. P. gingivalis–LPS is an activator of gene expression in macrophages isolated from tissues distinct from the oral cavity.
KEY WORDSCD14 MHC-II SR-A TLR4 mRNA expression changes Pg–LPS stimulation
The authors gratefully acknowledge Li and Zheng Heping and their staff (Comparative Medicine Department, Fuzhou General Hospital of Nanjing Military Region of PLA) for the outstanding care given to the animals used in this study. We also acknowledge the staff of the Oral Medical Research Center of Fujian Medical University for their enthusiastic support and help in performing the experiments. We would like to thank Editage (www.editage.com) for English language editing and Publication Support.
This study was funded by the National Natural Science Foundation of China [grant numbers 81371152, 30973326] and Natural Science Foundation of Fujian Province, China [grant number 2017J01809]. The funding agency had no role in the study design, collection, analysis, or interpretation of data, the writing of the report, or the decision to submit the article for publication.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflicts of interest.
This article does not contain any studies with human or animal subjects performed by any of the authors.
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