Kiyohide Ishihata

Three-dimensional analyses of facial soft tissue configuration of Japanese females with jaw deformity--a trial of polygonal view of facial soft tissue deformity in orthognathic patients.

In this study, we evaluated the three-dimensional (3D) soft tissue configuration of Japanese females with/without jaw deformity in order to establish the polygonal view of facial soft tissue deformity three-dimensionally. A polygonal chart was applied to assess the outcomes of orthognathic surgery for patients with mandibular hyperplasia with/without deviation. The study included 20 Japanese females with mandibular hyperplasia with/without deviation. All patients received mandibular setback surgery, and 3D measurements were carried out pre-operation, and at 1, 3 and 6 months postoperatively using a non-contact laser scanning system. Eighteen soft tissue landmarks were set on each 3D image and used to calculate a set of selected parameters. As controls, 20 Japanese females with class I occlusion were included. A polygonal chart was constructed based on the mean and S.D. of the control group. Patients with mandibular protrusion characteristically demonstrated significant variances in the items around the lower face. In asymmetric patients, deviation in the mental area disappeared postoperatively, but a small deviation remained when compared to the controls. The method used in this study seems to be a useful index for diagnosis and as a treatment plan for patients with mandibular hyperplasia with/without deviation.

A novel ameloblastoma cell line (AM-3) secretes MMP-9 in response to Wnt-3a and induces osteoclastogenesis

OBJECTIVE Ameloblastoma has a high risk of bone invasion and local recurrence. However, the mechanisms of bone invasion in ameloblastoma remain unclear. In this study, we established an experimental model for matrix metalloproteinase (MMP) induction and osteoclastogenesis using ameloblastoma-derived cells. STUDY DESIGN We established an ameloblastoma-derived cell line without viral genes and analyzed the expression of all Wnt and Frizzled members and MMPs by real-time reverse transcription-polymerase chain reaction, and analyzed the activity of MMP-2 and MMP-9 by the in-gel-gelatinase assay. RESULTS AM-3, newly established ameloblastoma-derived cells retained the morphology of primary-cultured ameloblastoma cells. AM-3 cells overexpressed the messenger RNA of Wnt-5a, Frizzled-2, MMP-2, and MMP-9 and showed the potential of osteoclastogenesis. In addition, Wnt-3a-treatment induced expression and activation of MMP-9 in AM-3 cells. CONCLUSIONS Our study suggests that AM-3 cells retained the characteristics of ameloblastoma, without acquiring typical features of cancer cells. Furthermore, Wnt signaling induced MMP-9 in ameloblastoma cells.

Snail1 expression in human colon cancer DLD-1 cells confers invasive properties without N-cadherin expression

The epithelial-mesenchymal transition (EMT) is a fundamental characteristic of carcinoma cells. EMT is generally associated with a change in cellular morphology from cobblestone to spindle shape, reduced expression of epithelial markers such as E-cadherin, and enhanced expression of mesenchymal markers such as N-cadherin. This EMT-associated reciprocal expression of E-cadherin and N-cadherin has been called the “cadherin switch”. Downregulation of E-cadherin enables cells to dissociate from colonies while upregulation of N-cadherin is associated with increased invasiveness. The transcription factor Snail1 induces these changes in various epithelial cell lines, including canine MDCK cells and human A431 cells. In the present study, we introduced a Snail1 expression vector into human DLD-1 cells and isolated stable transfectants. These cells showed changes in morphology, reduced expression of epithelial marker E-cadherin and occludin, and elevated invasion and migration. However, neither expression of N-cadherin protein nor its corresponding mRNA was detected. Therefore, elevated N-cadherin expression is not required for invasiveness of the cells.

Expression of antimicrobial peptides and E-cadherin in periapical lesions

Abstract Objective Radicular cysts and apical granulomas are inflammatory diseases that develop in association with an infected root canal. It is thought that persistent inflammation may stimulate proliferation of dental epithelial cells around the root to form a cyst. However, pathogenesis and the mechanism of epithelial proliferation have not been clarified. The purpose of this study is to examine the levels of chemical and physical antimicrobial activities of periapical lesions. Methods To explore the expression of antimicrobial peptides (AMPs) and E-cadherin in periapical lesions, 10 tissue specimens each of apical granulomas and radicular cysts were evaluated by immunohistochemistry using anti-AMPs [human neutrophil defensin (HNP), LL37, human beta-defensin (HBD)-1 and -2] and anti-E-cadherin antibody. In vitro assay to assess the expression of LL37, HBD-1, -2 and E-cadherin in the immortalized rat dental epithelial cell line (HAT-7) stimulated with/without lipopolysaccharide (LPS) or bacterial cells were detected by immunocytochemistry, quantitative real-time polymerase chain reaction and Western blot analysis. Cell proliferation after incubation with/without LPS or LL37 was assayed by MTT assay. Results HNP and LL37 were observed mainly in the neutrophils of apical granulomas, while HBD-1 and E-cadherin showed higher expression in radicular cysts than in apical granulomas. In vitro assays showed that bacterial stimulation enhanced expression of HBD-2, LL37, and E-cadherin, but epithelial cell proliferation was not enhanced with LPS and LL37. Conclusions These observations suggest that dental epithelial cells can secrete AMPs and consolidate epithelial intercellular junctions when stimulated by bacterial infection, and radicular cysts may play an important role in defense mechanisms.