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Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although the function and effects of many growth factors and extracellular matrix (ECM) molecules have been described for several periodontal tissues in vivo and in vitro, the molecular interactions involved in the communication between cells of the periodontal ligament and the alveolar bone are poorly understood. To contribute to the identification of such interactions, we have generated co-cultures (CCs) of periodontal ligament fibroblasts (PDLs) and alveolar bone cells (ABCs) and compared mRNA expression for various growth factors, ECM molecules, and matrix metalloproteinase13 (MMP13) after 1 and 2 weeks with matched mono-cultures (MCs) by reverse transcription/polymerase chain reaction. Compared with CCs of 1 week, PDLs and ABCs after 2 weeks revealed relatively high levels of all analyzed mRNAs, viz., for EGF, HGF, VEGF, TGFß1, collagen-I (COL1), osteonectin (ON), fibronectin (FN1), and MMP13. At week 2, when compared with MCs, CCs showed an elevation of all tested mRNAs in PDLs and ABCs, except for TGFß1 and FN1, which only increased in PDLs. After 1 week, when CCs were compared with MCs, mRNAs for HGF and TGFß1 were less abundant in PDLs and ABCs, whereas the other genes exhibited lower expression levels in only one of the cell types. Analysis of our data indicated that the expression of mRNAs for growth factors and for COL1, ON, FN1, and MMP13 was modulated in the distinct cell types with respect to culture time and culture type. The differences in the mRNA expression patterns between CCs and MCs suggest that the respective genes are involved in the molecular interactions of PDLs and ABCs. [ABSTRACT FROM AUTHOR]

Cells of the periodontal ligament and the alveolar bone lie in close vicinity in the periodontium. The goal of this study was to create an in vitro model to facilitate the study of the morphogenesis and proliferation of these two cell types under more in-vivo-like conditions. This was accomplished by the generation of organotypic co-cultures of primary human periodontal ligament fibroblasts (PDL) and alveolar bone cells (BC) and matched mono-cultures after 1, 2 and 3 weeks. Indirect immunofluorescence (IIF) for vimentin indicated that PDL cells exhibited sustained stratification only in the presence of BC cells, suggesting an important role for BCs in maintaining the stratification of PDL cells. In mono-cultures, only BC cells showed progressing stratification. They also displayed the most pronounced contraction of the cell culture matrix. Moreover, Ki-67 antigen detection by IIF revealed that these features coincided with cell proliferation localized on the matrix surface at the onset of cell stratification. These findings suggest that, in addition to proliferation, a further prerequisite for stratification may be cell migration. Furthermore, the maintained cell stratification, proliferation, and compartmentalization noted for PDL cells in organotypic co-cultures and BCs in mono-cultures can only be observed in a three-dimensional culture system. Thus, our system represents a novel experimental tool to further elucidate the underlying mechanisms of the growth and differentiation of PDL and bone tissue. [ABSTRACT FROM AUTHOR]

A decrease in gap junction-mediated cell-to-cell communication has previously been observed in monolayer cultures of human keratinocytes (HaCaT cells) expressing the human papillomavirus type 16 E5 (HPV16 E5) gene and attributed to the reduced phosphorylation of connexin 43, the most abundant connexin in HaCaT cells. In line with this observation, we have now analyzed the effect of HPV16 E5 on connexin 43 expression in raft cultures produced by transfected HaCaT cells. These keratinocytes transcribe HPV16 E5 under the control of a dexamethasone-inducible promoter. Our results show that treatment with dexamethasone leads to an almost complete disappearance of connexin 43 in rafts expressing the E5 gene but not in control rafts. In our study we discuss the possible effects of this downregulation on cell-cell communication and cellular malignant transformation. [ABSTRACT FROM AUTHOR]

Cell-matrix interactions and the ordered deposition of basement membrane (BM) components are of major importance for the maintenance of tissue homeostasis in complex epithelia. This aspect was studied in vitro in a coculture system designed as an oral mucosa model. As crucial epithelial features the kinetics of proliferation, expression of site-specific keratins as well as integrin patterns in correlation to synthesis of BM components were assessed by immunohistochemistry and in situ hybridization. Comparison with non-cornified gingiva as tissue of origin revealed different stages of epithelial development, eventually leading to complete reconstruction within a time frame of 1–3 weeks. First, the initial activated stage up to 1 week was characterized by (a) high keratinocyte proliferation, (b) extended expression of the basal cell-specific keratin K5 and (c) a patchy pattern of the differentiation-specific keratins K4 and K13. Second, after 2 weeks the improvement of histoarchitecture correlated to (a) predominant K5 expression in the basal and (b) extension of K4 and K13 within the suprabasal cell compartment, (c) high expression of integrins α3β1 and α6β4 including their ligand laminin-5 and (d) accumulating deposition of basement membrane components. Third, virtually complete tissue normalization at 3 weeks was indicated by (a) restriction of K5 to the basal cell area, (b) regular suprabasal localization of K4 and K13, (c) polarization of integrins to basal and parabasal cells and (d) linear codistribution of collagen IV, “classical” laminin (-1 or -10) and laminin-5 underneath the basal cells. Thus, these organotypic cocultures represent relevant equivalents for non-keratinized oral mucosa with typical gingival differentiation features and in addition suitable models for preclinical trials such as prospective dental material testing. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)