Yoshiki Sugiyama

High-cell density-induced VCAM1 expression inhibits the migratory ability of mesenchymal stem cells

MSCs (mesenchymal stem cells) migrate into damaged tissue and then proliferate and differentiate into various cell lineages to regenerate bone, cartilage, fat and muscle. Cell—cell adhesion of MSCs is essential for the MSC‐dependent tissue regeneration after their homing into a damaged tissue. However, it remains to be elucidated what kinds of adhesion molecules play important roles in the cell—cell communication between MSCs. In order to identify adhesion molecules that facilitate mutual contact between MSCs, a comprehensive analysis of mRNA expression in adhesion molecules was performed by comparing profiles of expression status of adhesion molecules in MSCs at low‐ and high‐cell density. We found that the expression level of VCAM1 (vascular cell adhesion molecule‐1)/CD106 was clearly up‐regulated in the human bone marrow‐derived MSCs—UE7T‐13 cells – under a condition of high cell density. Intriguingly, the migratory ability of the cells was clearly accelerated by a knockdown of VCAM1. Furthermore, the migratory ability of UE7T‐13 cells was decreased by the over expression of exogenous VCAM1. In addition, the high cell density‐induced expression of VCAM1 was clearly suppressed by NF‐κB (nuclear factor‐κB) signalling‐related protein kinase inhibitors such as an IKK‐2 (IκB kinase‐2) inhibitor VI. In conclusion, the high cell density‐induced VCAM1 expression through the NF‐κB pathway inhibits the migratory ability of human bone marrow‐derived MSCs.

Tumoral calcium pyrophosphate dihydrate crystal deposition disease of the temporomandibular joint: identification on crystallography.

This paper reports a case of calcium pyrophosphate dihydrate (CPPD) crystal deposition in the temporomandibular joint (TMJ) of a 59‐year‐old man with the chief complaint of severe pain in the left TMJ. On CT a radiopaque area was seen around the condylar process of the left TMJ with irregular destructive bony changes. A provisional diagnosis of crystalline‐induced arthritis was made on histopathology of a biopsy specimen. Electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and X‐ray diffraction showed both CPPD and hydroxyapatite (HA) in the crystalline materials. Identification of these two types of crystal in crystal deposition disease of TMJ, using crystallography, is discussed.

Cell-cell adhesion through N-cadherin enhances VCAM-1 expression via PDGFRβ in a ligand-independent manner in mesenchymal stem cells

Cell-cell adhesions induce various intracellular signals through hierarchical and synergistic molecular interactions. Recently, we demonstrated that a high cell density induces the expression of vascular cell adhesion molecule-1 (VCAM-1) through the nuclear factor-κB (NF-κB) pathway in human bone marrow-derived mesenchymal stem cells (MSCs). However, the specific molecules that activated the NF-κB pathway were not determined. In the present study, in experiments with receptor tyrosine kinase inhibitors, VCAM-1 expression was completely suppressed by platelet-derived growth factor (PDGF) receptor (PDGFR) inhibitors. In addition, VCAM-1 expression was significantly suppressed by knockdown with PDGFRβ siRNA, but not with PDGFRα siRNA. However, VCAM-1 expression did not increase following treatment with PDGF. The overexpression of N-cadherin, a structural molecule in adherence junctions in MSCs, promoted VCAM-1 expression and induced the marked phosphorylation of the intracellular signaling factor, Src. In addition, VCAM-1 expression and Src phosphorylation were reduced by the overexpression of a dominant negative mutant of N-cadherin. These results suggest that cell-cell adhesion, through N-cadherin, enhances the expression of VCAM-1 via PDGFRβ and the activation of Src in a ligand-independent manner in MSCs.

ANALYSIS OF ELEMENTS IN THE SOFT TISSUE COVERING TITANIUM PLATES AND SCREWS FOR INTERNAL BONE FIXATION BY THE PIXE METHOD

We made a comparative study of the elements in the periosteum on titanium plates and screws for internal bone fixation, normal periosteum, and oral mucosa by the PIXE method. We studied 11 patients, 4 men and 7 women, with mandibular fracture or facial deformity. The implanted time length of the materials in the body was 5 to 16 months. The analyzed samples were 11 periostea on the materials, 11 normal periostea and 4 oral mucosae. The results were as follows. Twenty-four essential and 11 contaminated elements were detected in the periostea on the materials as well as in the normal periostea and the oral mucosae. In the mean values of titanium and aluminum, there were significantly higher values in the periostea on the materials than in the normal periostea. The mean concentration values of the other elements did not differ significantly between that in the periostea on the materials and that in the normal periostea. The concentration of titanium in the periostea on the materials was not correlated with sex, age of the patients, or the implanted time length. However, there was a significantly higher titanium concentration value in the periostea on the plates than on the screws. Our results could indicate that the existence of a titanium element in the periostea on the materials was caused by its dissolution from the materials.

Cytopathologic diagnosis on joint lavage fluid for patients with temporomandibular joint disorders

Temporomandibular joint (TMJ) disorders (TMD) are usually diagnosed based on the patients clinical findings and the results of image investigations; however, understanding of the inflammatory process in TMJ is difficult. In addition, many of the TMJ disease types share common principal symptoms. Therefore, TMJ diseases in the early stage can be misdiagnosed with TMD. It is hypothesized that cytopathologic examination of the joint lavage fluids is useful in interpreting the TMD‐associated inflammatory process from a cellular aspect. The aim of this study was to assess the TMJ lavage fluid cytopathologically in TMD patients. Thirty‐nine patients, clinically diagnosed as TMD, were included in the present study. Clinical symptoms of the patients were recorded. Forty‐four samples of TMJ lavage fluid were collected and paraffin‐embedded cell sections were made by cell block tissue array method. Cytologic conditions in upper articular cavity of TMJ were cytopathologically diagnosed and were compared with the clinical symptoms of each patient. Cell components were detected in 22 of the 44 analyzed joint lavage fluids. There was a correlation between cytopathologic findings and clinical symptoms. Variety of cytopathology and inflammatory conditions in patients with similar clinical symptoms were also found. The results suggested that cytopathologic examination of the joint lavage fluids from TMD patients is helpful for gaining an understanding of the inner local conditions of TMJ at the cellular level. Diagn. Cytopathol. 2014;42:30–36.

TRACE ELEMENT ANALYSIS OF THE ORAL MUCOSA OF 22 PATIENTS WITH ORAL LICHEN PLANUS BY THE PIXE METHOD

We made a comparative study of the trace elements in the oral mucosa of 22 patients with oral lichen planus (OLP) and of 100 healthy persons by the PIXE method. Samples were excised from the oral mucosa of the OLP patients (OLP group) and from the buccal mucosa of healthy persons (control group). The results were as follows: Seventeen trace elements and 11 contaminating elements were detected in those oral mucosae. Al, Ti and Pb, which are contaminating elements, were detected in more than 65% of samples from both groups. The mean values of Se and Rb were significantly lower in the OLP group than in the control group. The mean values of the other elements did not differ significantly between the groups. As for the females over 30 years old, the OLP group showed significantly higher values of Zn and Sr than the control group. Their mean values of the other essential and contaminating elements did not differ significantly between the groups, although there was a trend toward higher values in the OLP group. We found by the PIXE method that Zn, Fe and Pd, which are d-transitional elements considered to cause allergic reaction, showed higher values in the oral mucosae of the OLP patients than in those of the healthy persons.

Zoledronic acid suppresses transforming growth factor-β-induced fibrogenesis by human gingival fibroblasts

Bisphosphonates (BPs) are analogues of pyro-phosphate that are known to prevent bone resorption by inhibiting osteoclast activity. Nitrogen-containing BPs, such as zoledronic acid (ZA), are widely used in the treatment of osteoporosis and bone metastasis. However, despite having benefits, ZA has been reported to induce BP-related osteonecrosis of the jaw (BRONJ) in cancer patients. The molecular pathological mechanisms responsible for the development of BRONJ, including necrotic bone exposure after tooth extraction, remain to be elucidated. In this study, we examined the effects of ZA on the transforming growth factor-β (TGF-β)-induced myofibroblast (MF) differentiation of human gingival fibroblasts (hGFs) and the migratory activity of hGFs, which are important for wound closure by fibrous tissue formation. The ZA maximum concentration in serum (Cmax) was found to be approximately 1.47 µM, which clinically, is found after the intravenous administration of 4 mg ZA, and ZA at this dose is considered appropriate for the treatment of cancer bone metastasis or bone diseases, such as Erdheim-Chester disease. At Cmax, ZA significantly suppressed i) the TGF-β-induced promotion of cell viability, ii) the TGF-β-induced expression of MF markers such as α-smooth muscle actin (α-SMA) and type I collagen, iii) the TGF-β-induced migratory activity of hGFs and iv) the expression level of TGF-β type I receptor on the surfaces of hGFs, as well as the TGF-β-induced phosphorylation of Smad2/3. Thus, ZA suppresses TGF-β-induced fibrous tissue formation by hGFs, possibly through the inhibition of Smad-dependent signal transduction. Our findings partly elucidate the molecular mechanisms underlying BRONJ and may prove to be beneficial to the identification of drug targets for the treatment of this symptom at the molecular level.

A huge osteoma of the mandible detected with head and neck computed tomography

Abstract We encountered a patient with a huge osteoma extending over half of the mandible, which was incidentally discovered on a head-and-neck computed tomography (CT) by an otolaryngological examination for vertigo. A tumorous lesion of the right mandible was noted, and the patient was referred to our department. The tumor extended from the median mandible over the right anterior margin of the ramus of the mandible. To improve the abnormal intraoral morphology, tumor resection and orthopedic surgery were performed. The histopathological diagnosis was a cancellous osteoma. Dentures were attached after surgery, and the postoperative course has been favorable with no tumor re-enlargement.

Dental pulp cells derived from permanent teeth express higher levels of R-cadherin than do deciduous teeth: implications of the correlation between R-cadherin expression and restriction of multipotency in mesenchymal stem cells.

OBJECTIVES The aim of this study was to characterize the expression status of cadherins in dental pulp-derived mesenchymal progenitor/stem cells from deciduous and permanent teeth, and to determine how cadherins affect the multipotency of the progenitor/stem cells. MATERIALS AND METHODS We evaluated and compared the expression status of cadherins in dental pulp-derived cells from deciduous teeth and in cells from permanent teeth by using an array of primers for amplification of RNA encoding human cell adhesion molecules and a real time PCR system. In order to elucidate how cadherins (which are differentially expressed in deciduous and permanent teeth) affect the multipotency of the dental pulp-derived progenitor/stem cells, the ability of the dental pulp cells to differentiate into adipocytes and osteoblasts was evaluated. RESULTS R-cadherin was found to be vigorously expressed in the dental pulp cells derived from permanent teeth but not in the dental pulp cells derived from deciduous teeth. N-cadherin was found to be expressed essentially equally in both types of cells. The ability of the dental pulp cells of deciduous teeth to differentiate into adipocytes and osteoblasts was found to be much higher than that of cells obtained from permanent teeth. CONCLUSION R-cadherin may be a key molecule for providing control over the multipotency of the dental pulp-derived mesenchymal stem cells.

Multiple distant organ metastases from squamous cell carcinoma of the lower gingiva that followed a rapid course: An autopsy case report

Abstract We experienced a rare case, which was distant organ metastatic squamous cell carcinoma (SCC) and had deteriorated rapidly. An 80-year-old man was transported to hospital because of a sudden loss of consciousness. A tumor was found in his right mandibular gingiva, which was histopathologically diagnosed as SCC. A large tumor was detected in the pelvic soft tissue on a thoracoabdominal computed tomography scan. The patient died on the 22nd day after he was admitted to hospital. We performed an autopsy. The autopsy revealed multiple distant organ metastases, and all of the lesions were histopathologically diagnosed as SCC.