Yes-associated protein（YAP）and transcriptional co-activator with PDZ-binding motif（TAZ）are widely expressed homologous protein, initially identified as a significant downstream effector in the Hippo signaling pathway that functions to regulate mammalian tissue and organ size. Tooth morphogenesis proceeds by controlled, continuous epithelial-mesenchymal interactions. We investigated the localization of YAP and TAZ in mouse incisor tooth germ using immunohistochemistry. Paraffin sections were prepared from the heads of ICR fetus mice at embryonic days 14 and 18, and immunohistochemical staining was performed using anti-YAP and anti-TAZ antibodies. YAP was localized in the odontogenic epithelium and mesenchyme from the cap stage of teeth, while TAZ was not localized at the cap stage. At the bell stage, YAP and TAZ showed similar expression patterns and apparent localization in ameloblasts and odontoblasts. These results suggest that YAP proteins are related to the proliferation and differentiation of odontogenic epithelium and mesenchyme, whereas, both YAP and TAZ proteins are involved in ameloblasts and odontoblasts differentiation, as well as in matrix production and mineralization during hard tissue formation.

Hippo signaling determine organ size by regulating cell proliferation, apoptosis, and cell differentiation. Yes-associated protein（YAP）and transcriptional coactivator with PDZ-binding motif（TAZ）are important transcriptional coactivators downstream of Hippo signaling. Salivary glands, the same as teeth, lungs, kidneys, etc., develop through epithelial-mesenchymal interactions, and are formed through repeated branching, which is common in glandular tissues. We examined the expression of YAP and TAZ proteins in the submandibular glands of mouse embryos using immunohistochemical staining to investigate the involvement of these proteins in the development of the submandibular glands ICR mouse embryos at days E14, E16 and E18. The localization of YAP and TAZ was similar during the submandibular glands development. YAP and TAZ proteins were expressed in the branch-forming epithelium from E14. E18 showed localization in the ductal epithelium and little expression in the acinar cells. These results suggest that YAP and TAZ proteins are involved in the development of the submandibular gland in embryonic mice, contributing to branching, cell proliferation, and duct formation.

Current imaging technology used in the medical field enables non-invasive observation of body tissues from the body surface. However, this method cannot depict the fine internal structure of tissues at high resolution, and in particular, it can be difficult to visualize granulation tissue without the use of contrast agents. Phase-contrast imaging, a new imaging method that has been actively investigated since the early 2000s, enables visualization of the phase shift of X-rays transmitted through matter. It emphasizes the components of scattering and refraction that occur when X-rays pass through a sample and is approximately 1,000 times more sensitive than absorption-contrast X-ray imaging for observing the fine structure of granulation tissue of the tongue. In the present study, the authors used an X-ray phase-contrast imaging technique termed the diffraction enhancement method to acquire absorption images, refraction-angle images, and ultra-small angle X-ray scattering images of paraffin-embedded granulation tissue of the tongue. The results showed that even in samples with almost uniformly homogenized density due to paraffin embedding, clear images of internal structures could be obtained using synchrotron radiation and perfect crystals, and that visualization of granulation tissue appears possible depending on the sample preparation and irradiation conditions. These findings suggest that explicit images and three-dimensional structures obtained by phase-contrast imaging could potentially provide valuable information towards the evolution of diagnostic imaging techniques and the formulation of treatment plans, and that phase-contrast imaging is an important advancement in the medical field.

Hyperglycemia is a major factor of diabetes. Respiratory symptoms are frequently observed in people with diabetes. It is well known that periodontitis is associated with developmental of diabetes. Fusobacterium nucleatum（F. nucleatum）is one of major pathogen of periodontitis. Isolation frequency of F. nucleatum in gingival crevicular fluid of diabetes patients is greater than those in non-diabetes control and, furthermore, also positively correlated with fasting blood glucose and glycated hemoglobin levels. In addition, F. nucleatum exacerbates chronic obstructive pulmonary disease. Therefore, we examined the effect of F. nucleatum on human bronchial fibroblasts（HBFs）cultured in normal glucose（NG）, high glucose（HG）and NG with mannitol as osmotic control （MG）.

We performed invasion assay for F. nucleatum into HBFs and examined the protein and mRNA expressions of intercellular adhesion molecule-1（ICAM-1）. We next examined the protein expressions of toll-like receptor（TLR）2, TLR4 and the receptors for advanced glycation end products（RAGE）in HBFs inoculated with F. nucleatum. We analyzed mRNA expression of interleukin-6（IL-6）triggered by TLR2, TLR4 and RAGE. In addition, we confirmed IL-6 production in HBFs pre-treated with inhibitors of nuclear factor-kappa B（NF-κB）and extracellular signal-regulated kinase 1/2（ERK1/2）before inoculation with F. nucleatum.

The numbers of intracellular F. nucleatum were significantly higher in HG group than in NG group. The protein and mRNA expressions of ICMA-1 were increased in HG group inoculated with F. nucleatum. The protein expressions of TLR2, TLR4 and RAGE and mRNA expression of IL-6 were enhanced in HG group inoculated with F. nucleatum. In addition, IL-6 production was reduced by inhibitors of NF-κB and ERK1/2.

Our results indicated that HG promoted the invasion of F. nucleatum through ICAM-1 expression in HBFs. We propose that HG-induced over expression of TLR2, TLR4 and RAGE leads to mRNA expression of IL-6 through NF-κB and ERK1/2.

The gram-negative bacterium Porphyromonas gingivalis（Pg）is implicated in periodontal disease. Lipopolysaccharide（LPS）, a component of the gram-negative bacterial cell wall, contributes to periodontal tissue destruction. The intra-gingival application of Pg-derived LPS（Pg-LPS）increases gingival TNF-alpha without affecting IL-6 in rats. Recognizing periodontal infection’s potential threat to health, we investigated the effects of intra-gingival Pg-LPS application on plasma TNF-alpha and IL-6 levels. For comparison, we analyzed the effects of LPS derived from Escherichia coli（Ec-LPS）.

Male Sprague-Dawley rats were employed, with each anaesthetised using urethane. The external jugular vein was cannulated for blood sampling and intravenous LPS administration. IL-6 and TNF-alpha levels were determined using enzyme-linked immunosorbent assay and bead-based Multi-Plex kits. Intra-gingival administration of Pg-LPS（1 µg）, but not Ec-LPS（1 µg）, increased TNF-alpha without affecting IL-6 in blood samples. Intravenous administration of a high dose of Ec-LPS（5 mg/kg）, but not the intra-gingivally applied dose（1 µg）of Ec- or Pg-LPS, increased blood TNF-alpha and IL-6 levels.

These findings suggest that intra-gingivally administered Pg-LPS increases blood TNF-alpha by binding to gingival Toll-like receptor subtypes, recognizing LPS and increasing TNF-alpha secretion. Alternatively, this increase may be mediated by translocation of TNF-alpha from the gingival extracellular space into the bloodstream.