Gastrin-Releasing Peptide (GRP) Stimulates Osteoclastogenesis in Periodontitis.
YunJeong ChoiSoon-Chul HeoYu Na KimJi-Young JooJae Joon HwangMoon-Kyoung BaeHyung Joon KimPublished in: Cells (2020)
Periodontitis is a chronic inflammatory disease with alveolar bone resorption and subsequent tooth loss as its ultimate outcomes. Gastrin-releasing peptide (GRP) is a neuropeptide with growth-stimulatory and tumorigenic properties, and neuropeptides have previously been suggested to play a role in the complex cascade of chemical activity associated with periodontal inflammation. In this study, GRP treatment enhanced the differentiation of bone marrow-derived macrophages (BMMs) into osteoclasts, and gastrin-releasing peptide receptor (GRPR) antagonists suppressed the pro-osteoclastogenic effect of GRP. Grpr-siRNA knockdown resulted in a significantly lower number of osteoclasts formed as compared with the control. Interestingly, gene expression analysis indicated downregulation of Grp and Grpr expressions in BMMs during osteoclastogenesis. Moreover, ligature-induced periodontitis model in mice and gingival samples from patients with periodontitis displayed increased immunostaining of GRP in the oral epithelium. Subsequently, stimulation of mouse primary epithelial cells (ECs) and HaCaT cells, human epidermal keratinocytes, with lipopolysaccharides (LPS) of Porphyromonas gingivalis or live P. gingivalis upregulated Grp and Grpr expressions. Finally, coculture of P. gingivalis-stimulated ECs and BMMs using Transwell system revealed that the differentiation of BMMs was induced when subjected to paracrine activation by LPS- as well as live-P. gingivalis stimulated ECs. Taken together, our results demonstrate that the pro-osteoclastogenic properties of BMMs may be modulated by GRP produced by ECs in the periodontal microenvironment.
Keyphrases
- endoplasmic reticulum stress
- cell surface
- induced apoptosis
- bone loss
- anti inflammatory
- oxidative stress
- inflammatory response
- endothelial cells
- stem cells
- high glucose
- type diabetes
- single cell
- transcription factor
- skeletal muscle
- drug delivery
- genome wide identification
- cell cycle arrest
- bone marrow
- postmenopausal women
- glycemic control
- bone regeneration
- pluripotent stem cells
- hyaluronic acid
- induced pluripotent stem cells