Kaixian Yan1, Qin Lin2, Kailiang Tang2, Shuang Liu1, Yi Du2, Xijiao Yu3,4, Shu Li5. 1. Department of Periodontology, School and Hospital of Stomatology, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, 250012, Jinan, Shandong, People's Republic of China. 2. Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China. 3. Department of Periodontology, School and Hospital of Stomatology, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, 250012, Jinan, Shandong, People's Republic of China. yayiyu@163.com. 4. Department of Endodontics, Jinan Stomatological Hospital, Jinan, Shandong, People's Republic of China. yayiyu@163.com. 5. Department of Periodontology, School and Hospital of Stomatology, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, 250012, Jinan, Shandong, People's Republic of China. lishu@sdu.edu.cn.
Abstract
BACKGROUND: Both substance P and hypoxia-inducible factor 1 alpha (HIF-1α) are involved in inflammation and angiogenesis. However, the relationship between substance P and HIF-1α in rat periodontitis is still unknown. METHODS: Ligation-induced rat periodontitis was established to observe the distribution and expression of substance P and HIF-1α by immunohistochemistry. Rat gingival fibroblasts were cultured and stimulated with Porphyromonas gingivalis lipopolysaccharide (LPS). Recombinant substance P was applied to elaborate the relationship between substance P and HIF-1α in gingival fibroblasts in vitro. Primary mouse bone marrow-derived macrophages (BMMs) were isolated and cultured to observe the effect of substance P on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis by TRAP staining. Western blotting was used to investigate the expression of HIF-1α, osteoprotegerin (OPG) and RANKL. RESULTS: Rat experimental periodontitis was successfully established 6 weeks after ligation. Gingival inflammatory infiltration and alveolar bone loss were observed. Positive expression of substance P was found in the infiltrating cells. Higher HIF-1α levels were observed in periodontitis compared to that of normal tissues. Substance P upregulated the level of HIF-1α in gingival fibroblasts with or without 1 μg/ml LPS in vitro (*P < 0.05). Substance P upregulated the expression of HIF-1α in RANKL-stimulated BMMs in vitro. Substance P also increased the RANKL/OPG ratio in gingival fibroblasts (*P < 0.05). Both 10 nM and 50 nM substance P promoted RANKL-induced osteoclast differentiation (*P < 0.05). CONCLUSION: Substance P participates in periodontitis by upregulating HIF-1α and the RANKL/OPG ratio.
BACKGROUND: Both substance P andhypoxia-inducible factor 1 alpha (HIF-1α) are involved in inflammation and angiogenesis. However, the relationship between substance P and HIF-1α in ratperiodontitis is still unknown. METHODS: Ligation-inducedratperiodontitis was established to observe the distribution and expression of substance P and HIF-1α by immunohistochemistry. Rat gingival fibroblasts were cultured and stimulated with Porphyromonas gingivalislipopolysaccharide (LPS). Recombinant substance P was applied to elaborate the relationship between substance P and HIF-1α in gingival fibroblasts in vitro. Primary mouse bone marrow-derived macrophages (BMMs) were isolated and cultured to observe the effect of substance P on receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis by TRAP staining. Western blotting was used to investigate the expression of HIF-1α, osteoprotegerin (OPG) andRANKL. RESULTS:Rat experimental periodontitis was successfully established 6 weeks after ligation. Gingival inflammatory infiltration andalveolar bone loss were observed. Positive expression of substance P was found in the infiltrating cells. Higher HIF-1α levels were observed in periodontitis compared to that of normal tissues. Substance P upregulated the level of HIF-1α in gingival fibroblasts with or without 1 μg/ml LPS in vitro (*P < 0.05). Substance P upregulated the expression of HIF-1α in RANKL-stimulated BMMs in vitro. Substance P also increased the RANKL/OPGratio in gingival fibroblasts (*P < 0.05). Both 10 nM and 50 nM substance P promotedRANKL-induced osteoclast differentiation (*P < 0.05). CONCLUSION:Substance P participates in periodontitis by upregulating HIF-1α and the RANKL/OPGratio.
Entities:
Keywords:
HIF-1α; Osteoclast; RANKL/OPG; Substance P