- 著者
- Satoko Iwasa Hirotaka Ota Kensuke Nishio Mariko Ohtsu Masafumi Kusunoki Takahiro Gojoubori Tetsuo Shirakawa Masatake Asano
- 出版者
- 日本大学歯学部
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- vol.58, no.3, pp.317-323, 2016 (Released:2016-09-25)
- 参考文献数
- 25
- 被引用文献数
- 4
Toll-like receptors (TLR) recognize microbe-associated molecular patterns and induce the innate immune response. Among them, TLR5 recognizes the Gram-negative bacterial component flagellin. The aim of this study was to examine the expression of TLR5 in mouse salivary gland (SG). The SG was excised from 8- to 10-week-old female C57BL/6 mice. Salivary gland epithelial cells (SGECs) were purified and subjected to reverse transcription polymerase chain reaction (RT-PCR). Western blotting was performed to detect TLR5 expression at the protein level in several organs. The localization of TLR5 in SG was examined using immunohistochemical staining. The responsiveness of SGECs to flagellin was further examined by evaluating the induction of CXCL1 by real-time PCR and immunoprecipitation followed by Western blotting. TLR5 expression in SG was confirmed at the gene and protein levels. Immunohistochemical staining detected TLR5 in both acinic and ductal cells of the sublingual gland, but not in serous acinic cells of the submandibular gland. Although TLR5 was detected throughout the cytoplasm in ductal cells, positive staining was observed on the basal side of the mucous acinic cells. The purified SGECs responded to flagellin and induced the production of CXCL1. These findings suggest that TLR5 is functionally expressed in the SG and responds to its cognate ligand flagellin. (J Oral Sci 58, 317-323, 2016)
- 著者
- Hisanori Ito Takashi Kifune Misa Ishiyama Satoko Iwasa Hiroki Takei Tomokazu Hasegawa Masatake Asano Tetsuo Shirakawa
- 出版者
- Nihon University School of Dentistry
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- vol.60, no.4, pp.544-551, 2018 (Released:2018-12-27)
- 参考文献数
- 30
- 被引用文献数
- 5
Hypoxia after traumatic injuries to a tooth is one of the causes of subsequent root resorption. Inflammatory cytokines produced under hypoxic conditions are associated with root resorption, but the mechanism has not been fully understood. In this study, the role of hypoxia-inducible factor-1 (HIF-1) signaling in the regulation of CCAAT (cytosine-cytosine-adenosine-adenosine-thymidine)/enhancer-binding protein-β (C/EBPβ) and the receptor activator of nuclear factor kappa-B ligand (RANKL) expressions in immortalized human periodontal ligament (PDL) cells was investigated. PDL cells cultured under a hypoxic condition showed an increase in the expression of C/EBPβ and RANKL messenger RNAs (mRNAs), whereas the expression of osteoprotegerin and HIF-1α mRNAs was unaffected. Hypoxia had no effects on the secretion of interleukin (IL)-1β, IL-6, IL-8, IL-17A, tumor necrosis factor-alpha, macrophage migration inhibitory factor, monocyte chemoattractant protein-1, and macrophage colony-stimulating factor in the culture media. Treatment of the cells with dimethyloxaloylglycine, a competitive HIF prolyl hydroxylase inhibitor, significantly increased the expression of C/EBPβ and RANKL mRNAs. This suggested that the hypoxia-induced elevation of C/EBPβ and RANKL mRNAs was dependent on the HIF-1 activity. PDL cells transfected with a specific small interfering RNA designed to target the C/EBPβ gene showed a significant suppression of the RANKL mRNA. These findings indicated that C/EBPβ may play an important role in tooth root resorption via RANKL activation in hypoxia-exposed PDL cells.
- 著者
- Takashi Kifune Hisanori Ito Misa Ishiyama Satoko Iwasa Hiroki Takei Tomokazu Hasegawa Masatake Asano Tetsuo Shirakawa
- 出版者
- Nihon University School of Dentistry
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- vol.60, no.4, pp.519-525, 2018 (Released:2018-12-27)
- 参考文献数
- 32
- 被引用文献数
- 11
Hypoxia induces complex cellular responses that are mediated by a key transcription factor, hypoxia-inducible factor-1 (HIF-1). HIF-1 promotes production of cytokines and angiogenic factors and contributes to recovery of injured tissues. In the present study, expressions of angiogenin (ANG) and vascular endothelial growth factor (VEGF), which are potent angiogenic factors in mammalian tissues, were examined in immortalized fibroblasts exposed to hypoxia. After 24 h of exposure to hypoxia, ANG and VEGF mRNAs expressions were significantly elevated in periodontal ligament (PDL) fibroblasts but not in embryonic fibroblasts. Hypoxia also increased productions of ANG and VEGF proteins in PDL fibroblasts. HIF-1α mRNA expression was not affected by hypoxia in either fibroblast, although HIF-1α protein expression was enhanced after exposure to hypoxia. Treatment of PDL fibroblasts with dimethyloxaloylglycine, a prolyl hydroxylase inhibitor that stabilizes the HIF-1α protein, significantly increased expressions of ANG and VEGF mRNAs under normoxia. This suggests that stabilization of HIF-1α is crucial for upregulation of ANG and VEGF in PDL fibroblasts. These results indicate that, under hypoxic conditions, HIF-1α upregulates synthesis of ANG and VEGF in PDL fibroblasts and promotes angiogenesis.