Involvement of ADAM12 in Chondrocyte Differentiation by Regulation of TGF-ß1-Induced IGF-1 and RUNX-2 Expressions.

A disintegrin and metalloproteinase 12 (ADAM12) is known to be involved in chondrocyte proliferation and maturation; however, the mechanisms are not fully understood. In this study, expression and localization of ADAM12 during chondrocyte differentiation were examined in the mouse growth plate by immunohistochemistry. Adam12 expression during ATDC5 chondrogenic differentiation was examined by real-time PCR and compared with the expression pattern of type X collagen. The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system was used to generate Adam12-knockout (KO) ATDC5 cells. Adam12-KO and Adam12 overexpressing cells were used for analyses of ADAM12 expression with or without TGF-ß1 stimulation. ADAM12 was identified predominantly in chondrocytes of the proliferative zone in mouse growth plates by immunohistochemistry. Adam12 was upregulated prior to Col10a1 during chondrogenic differentiation in wild-type ATDC5 cells. In Adam12-KO ATDC5 cells, following initiation of chondrogenic differentiation, we observed a reduction in Igf-1 expression along with an upregulation of hypertrophy-associated Runx2, Col10a1, and type X collagen protein expressions. In ATDC5 wild-type cells, stimulation with TGF-ß1 upregulated the expressions of Adam12 and Igf-1 and downregulated the expression of Runx2. In contrast, in Adam12-KO ATDC5 cells, these TGF-ß1-induced changes were suppressed. Adam12 overexpression resulted in an upregulation of Igf-1 and downregulation of Runx2 expression in ATDC5 cells. The findings suggest that ADAM12 has important role in the regulation of chondrocyte differentiation, potentially by regulation of TGF-ß1-dependent signaling and that targeting of ADAM12 may have a role in management of abnormal chondrocyte differentiation.

Caveolin-1 Promotes Early Neuronal Maturation via Caveolae-Independent Trafficking of N-Cadherin and L1.

Axon specification is morphologically reproducible in vitro, whereas dendrite formation differs in vitro and in vivo. Cortical neurons initially develop immature neurites, but in vivo these are eliminated concurrently with the formation of a leading process, the future dendrite. However, the molecular mechanisms underlying these neuronal maturation events remain unclear. Here we show that caveolin-1, a major component of caveolae that are never observed in neurons, regulates in vivo-specific steps of neuronal maturation. Caveolin-1 is predominantly expressed in immature cortical neurons and regulates clathrin-independent endocytosis. In vivo knockdown of caveolin-1 disturbs immature neurite pruning, leading process elongation, and subsequent neuronal migration. Importantly, N-cadherin and L1, which are required for immature neurite formation, undergo caveolin-1-mediated endocytosis to eliminate immature neurites. Collectively, our findings indicate that caveolin-1 regulates N-cadherin and L1 trafficking independent of caveolae, which contributes to spatiotemporally restricted cellular events; immature neurite pruning and leading process elongation during early neuronal maturation.

Antiobesity Action of ACAM by Modulating the Dynamics of Cell Adhesion and Actin Polymerization in Adipocytes.

Coxsackie virus and adenovirus receptor-like membrane protein (CLMP) was identified as the tight junction-associated transmembrane protein of epithelial cells with homophilic binding activities. CLMP is also recognized as adipocyte adhesion molecule (ACAM), and it is upregulated in mature adipocytes in rodents and humans with obesity. Here, we present that aP2 promoter-driven ACAM transgenic mice are protected from obesity and diabetes with the prominent reduction of adipose tissue mass and smaller size of adipocytes. ACAM is abundantly expressed on plasma membrane of mature adipocytes and associated with formation of phalloidin-positive polymerized form of cortical actin (F-actin). By electron microscopy, the structure of zonula adherens with an intercellular space of ∼10-20 nm was observed with strict parallelism of the adjoining cell membranes over distances of 1-20 µm, where ACAM and γ-actin are abundantly expressed. The formation of zonula adherens may increase the mechanical strength, inhibit the adipocyte hypertrophy, and improve the insulin sensitivity.

Comparison of clinical practice education in dental hygiene schools in eight countries.

OBJECTIVES: The profession of dental hygienist is one of the few in which the primary function of the practitioner is to prevent oral disease and to promote the well-being of patients. The aim of this study was to investigate clinical training conditions in schools of dental hygiene in eight countries (the USA, Canada, the UK, Sweden, Denmark, Thailand, South Korea and Japan). METHODS: In 2006, we sent out a questionnaire in which we asked dental hygiene schools about how they educate dental hygiene students. RESULTS: The techniques taught to students in schools in Western industrialised nations, such as the USA, Canada, Denmark, the UK and Sweden, were mainly related to dental preventive measures and dental health guidance. By contrast, training schools in South Korea and Japan placed less emphasis on dental preventive measures and dental health guidance. Dental hygienists in Thailand are trained to perform local anaesthesia and to fill and extract deciduous teeth although the country does not have a specific qualification system. CONCLUSIONS: The contents of clinical training and education in schools of dental hygiene differ greatly among countries.

Percentile curves for food acceptance response scores in assessing chewing functions in adults.

The purpose of this study was to evaluate whether percentile curves for food acceptance response scores were useful in assessing oral and occlusal conditions. We used data obtained from Chiba City Patient Surveys (males: 1,276, females: 1,381, aged 20 to 64), which were conducted in 1998 and 1999. Subjects were assigned scores of between 1 and 4 for 31 different kinds of food based on their food acceptance responses. Occlusal conditions were measured with pressure-sensitive sheets. We calculated the percentile values from 5 to 95 at intervals of five years. We divided the subjects into two groups at the twenty-fifth percentile and statistically analyzed various oral conditions in the two groups. Significant differences were found between them in the mean numbers of present, sound, and missing teeth for almost all age groups. Moreover, there were significant differences in tooth-contact area and occlusal force between the two groups. The results of multiple regression analysis revealed that the scores had a stronger correlation with occlusal conditions than number of teeth in 55-year-olds, although the effect teeth-factors had on scores was more significant in 45- to 50-year-old males. Females' scores had a stronger correlation with occlusal conditions than number of teeth in all age groups. These results indicate that the questionnaire on the acceptance of 31 different kinds of food is useful in providing a basis for oral health instruction and dental treatment aimed at improving chewing ability in adults.

Relationship between number of present teeth and nutritional intake in institutionalized elderly.

We conducted oral examinations and dietary surveys on a total of 141 subjects with an average age of 80 years or more-specifically, seniors (S-group) living in a health service facility for the elderly and patients with mild dementia (SD-group) living in a special nursing home for the elderly. All were assumed to have a roughly uniform diet. We investigated which factors contributed to their dietary intake, and the relationship between dietary intake and number of present teeth (PT). Factors affecting total energy of the subjects and those in the S-group were body weight and number of PT. No factors were recognized as having a relationship with total energy in the SD-group. A significant difference was found in males in the S-group in that those in the "five PT or more" group had higher levels of carbohydrates and vitamin B1) than those in the "four PT or less" group. However, significant differences were found in the SD-group in that subjects in the "five PT or more" group had higher levels of carbohydrates, calcium, iron, and vitamins A, B1, B2, and C than those in the "four PT or less" group. Significant differences were seen in both groups for female patients in the nursing home with regard to total energy, proteins, carbohydrates, iron, vitamin B1, and fiber intake. No significant differences were recognized, however, for females in the SD-group. Reductions in dietary intake should be considered from the perspective of nutritional status, which is a problem that can be resolved through dental treatment. This study found that recovery of chewing ability in seniors was essential not only to maintain nutritional status, but also to fully bring out all the functions of the foods themselves.