Evaluation of inductive effects of different concentrations of cyclosporine A on MMP-1, MMP-2, MMP-3, TIMP-1, and TIMP-2 in fetal and adult human gingival fibroblasts.

Background The etiology of gingival overgrowth due to cyclosporine A (CsA) is still unknown. The aim of this study was to determine the possible role of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) on extra-cellular matrix (ECM) homeostasis when treated with different levels of CsA and its difference between fetal and adult human gingival fibroblasts (HGFs). Methods Each group of cells (adult and fetal) was cultured in 40 wells that consisted of four different CsA treatment concentrations. Every 10 wells were treated with 0, 50, 100, and 150 ng/mL of CsA which makes a total of 80 wells. Supernatants of every well were used to determine the concentration of MMPs and TIMPs using the Elisa kits from Boster, CA, USA. Results MMP-1 level increased with the treatment of CsA when treated with 50 and 150 ng/mL of CsA (p = 0.02 and p = 0.04) as TIMP-1 decreased (p < 0.0001) in adult group; while in the fetal group, TIMP-1 level increased with treatment of 150 ng/mL (p < 0.0001). MMP-2 level increased in both adult and fetal groups (p < 0.0001). MMP-3 level decreased in adult group (p < 0.0001) but went up in fetal HGFs (p = 0.01) when treated with 150 ng/mL CsA. TIMP-2 level increased in all wells significantly when treated with CsA (p < 0.0001). The study showed that CsA affects secretion of MMPs and TIMPs. MMP-1 increment and TIMP-1 decrement were observed, which indicate more degradation of ECM. This may be due to single donor use in this study. TIMP-2 and MMP-2 were both more active when treated with CsA which may be due to the gelatinase activity of them and that in CsA gingival overgrowth. There was more inflammation rather than fibrosis.

[Cleft lip and palate]. / Lippen-Kiefer-Gaumen-Spalten.

BACKGROUND: Cleft lip and palate (CLP) represents a group of malformations of unknown etiology but similar phenotypes. This implies consequences for the diagnostics, therapy, prevention, prognosis and risk estimation. OBJECTIVE: Definition of CLP subtypes and the embryonic development, clarification of correlations and differences between entities using epidemiological data, overview of the present state of genetic analyses, correlation to syndromes, sequences and associations and resulting consequences for clinical practice. MATERIAL AND METHODS: Update on embryological development of the face, summary of epidemiological and genetic studies and considerations on pedopathological and forensic aspects. RESULTS: Syndromic and non-syndromic CLP exhibit different and highly variable etiologies, therapeutic needs and prognosis. A thorough understanding is mandatory to distinguish between the different subgroups. In addition to specific aspects of CLP for the pediatric (forensic) pathologist this article provides an overall view of the topic which aims to help understand these malformations.

Expression of prostaglandin E synthases in periodontitis immunolocalization and cellular regulation.

The inflammatory mediator prostaglandin E(2) (PGE(2)) is implicated in the pathogenesis of chronic inflammatory diseases including periodontitis; it is synthesized by cyclooxygenases (COX) and the prostaglandin E synthases mPGES-1, mPGES-2, and cPGES. The distribution of PGES in gingival tissue of patients with periodontitis and the contribution of these enzymes to inflammation-induced PGE(2) synthesis in different cell types was investigated. In gingival biopsies, positive staining for PGES was observed in fibroblasts and endothelial, smooth muscle, epithelial, and immune cells. To further explore the contribution of PGES to inflammation-induced PGE(2) production, in vitro cell culture experiments were performed using fibroblasts and endothelial, smooth muscle, and mast cells. All cell types expressed PGES and COX-2, resulting in basal levels of PGE(2) synthesis. In response to tumor necrosis factor (TNF-α), IL-1ß, and cocultured lymphocytes, however, mPGES-1 and COX-2 protein expression increased in fibroblasts and smooth muscle cells, accompanied by increased PGE(2), whereas mPGES-2 and cPGES were unaffected. In endothelial cells, TNF-α increased PGE(2) production only via COX-2 expression, whereas in mast cells the cytokines did not affect PGE(2) enzyme expression or PGE(2) production. Furthermore, PGE(2) production was diminished in gingival fibroblasts derived from mPGES-1 knockout mice, compared with wild-type fibroblasts. These results suggest that fibroblasts and smooth muscle cells are important sources of mPGES-1, which may contribute to increased PGE(2) production in the inflammatory condition periodontitis.

Observations on early development of the murine fetal oral vestibule.

Morphological and immuno/histochemical studies were performed on the vestibular lamina (VL) of gestational day 13 murine fetuses, using light microscopy (LM), confocal laser scanning microscopy (CLSM) and transmission electron microscopy (TEM), in an effort to elucidate the early development of the oral vestibule. Histochemistry employing LM demonstrated some PAS-positive glycogen particles in embryonic cells of the VL, dental lamina (DL), the primary epithelial band connecting the VL and DL, and the related stomodaeal simple epithelium. On the other hand, Gomori's aldehyde fuchsine method stained certain cystine-containing intracellular granules and intercellular amorphous substances, particularly in the central VL. Intense immunoreactivity for CK-10 intermediate-sized filament proteins was demonstrated in suprabasal and superficial cells of the VL stratified keratinized epithelium. Conversely, reactions for CK-19 filaments were found diffusely in both VL and DL cells retaining the cytokeratin characteristic of the simple epithelium. TEM of the VL revealed an increment in keratinosomes, tonofilaments and desmosomes in the suprabasal layers shifting toward superficial flat parakeratinized cells. The TUNEL method using CLSM detected programmed cell death in the VL, while TEM provided no morphological evidence of necrosis or typical apoptotic features during VL development. The present results indicate that physiological (naturally occurring) cell death and exfoliation of the oral-gingival type multilayered keratinizing epithelium are essential for degeneration and separation of the VL, ultimately leading to formation of the oral vestibule.

The soft connective tissues of the gingiva and periodontal ligament: are they unique?

The connective tissues of the gingiva and periodontal ligament share a common embryonic development from cells of the cranial neural crest. This review paper describes the relationship of these tissues in tooth germ initiation, development and eruption.

Development and physiological degradation of tooth buds and development of rudiment of baleen plate in southern minke whale, Balaenoptera acutorostrata.

The development and degradation of temporary tooth buds and the development of rudiment of baleen plate were observed by gross-anatomical and histological examinations in twenty-four fetuses of the southern minke whale, Balaenoptera acutorostrata. The primary patterns of development of tooth buds were similar to those of deciduous tooth buds in the terrestrial species. Degradation of tooth buds was observed in the fetuses more than 615 mm body length (BL) and might proceed throughout the dental surface of the tooth buds. That degradation pattern was a little different from that of deciduous tooth buds in terrestrial species, which has a limited degradation area at the root of the tooth buds. In the fetuses with 135 and 153 mm BL, the upper jaw had a larger number of tooth buds than the lower jaw, although the number of buds varied in different individuals. Formation of rudiment of baleen plate was observed with degraded tooth buds in the fetus of 903 mm BL and it may be induced by the degradation of tooth buds.

Changes in cytokeratin expression during the development of the human oral mucosa.

The changes in cytokeratin expression by the developing oral mucosa of 10 to 23-week-old human fetuses were studied by indirect immunofluorescence using a panel of 15 monoclonal antibodies. The lining and masticatory mucosae were incompletely differentiated in 10-wk fetuses, since they expressed identical patterns of cytokeratins (CK 4, 5, 8, 13, 18, 19 and probably CK 14, 16, 17) very similar to that of adult alveolar mucosa. The main difference was the presence of cytokeratins 8, 18 and 19 in embryonic tissues. Cytokeratins 1, 2, 10 and 11 began to appear in gingival and hard palate epithelium from wk 11, predicting the differentiation of the masticatory mucosa by wk 16. The patterns of cytokeratin expression in the 23-wk fetus in the lining and masticatory mucosae appear to be different. In lining mucosa, the only difference from the 10th wk is a decrease in cytokeratins 8, 18 and 19, whereas the pattern of cytokeratin expression in masticatory mucosa (CK 1, 2, 4, 5, 8, 10, 11, 13, 18, 19 and probably CK 14, 16 and 17) is now very near that of adult gingiva. This pattern appears, as in the adult, to be similar to that of the epidermis in the same period.

[Situation and extension of epithelial excrescences alongside the lip furrow band and the dental lamina]. / Zur Lage und Ausdehnung von Epitheleinsenkungen neben Vestibularleiste und Zahnleiste.

3-D-reconstructions of serial sections of human embryos show that the margin of the lip furrow band is irregular and consists of an abundance of individual epithelial excrescences. Additional foldings of the lip furrow band extending over a length of up to 160 microns were found. The hypothesis that epithelial foldings in this region may be early anlagen of a perlacteal dentition is discussed and rejected.

[Development and structure of epithelial formations of the connective tissue stroma of human gingiva]. / Razvitie i stroenie épitelial'nykh obrazovanii soedinitel'no- tkannoi stromy desen cheloveka.

Processes of development and structure of epithelial formations, localized in the connective tissue framework of the gingival mucous membrane have been studied. During the prenatal period of development they are presented as epithelial pearls of Serra, and after birth--as remnants of ++tooth-forming epithelium (RTE). They are remnants of sheaths of the destroyed pearls. The latter, like RTE in the gingival stroma, have a genetic connection with the epithelial islets of Malasser and can cause some diseases in the gingiva.

Human oral epithelial cell culture. II. Keratin expression in fetal and adult gingival cells.

Epithelial cells from human fetal and adult gingiva were cultured in keratinocyte growth medium (KGM), a serum-free medium. The expression of keratin proteins in these cells was evaluated using immunohistochemistry and SDS-PAGE-immunoblot analysis and compared with expression in the tissue. Keratins 5, 6, 14, 16, and 19 were identified in cells cultured from both fetal and adult tissues. K19 was localized in basal cells of fetal oral tissue but was not seen in adult gingiva (except for scattered Merkel cells). K1 and K10 were expressed in tissue, but not in cultured cells. The keratin profiles of cultured epithelial cells from several adult donors were similar and were identical in cultures from primary through Passage 5. K13, a differentiation-specific keratin, was expressed in all suprabasal cells of fetal oral epithelium, but shows only spotty expression in adult gingival tissue. K13 was expressed in cultures of fetal cells, but very weakly or not at all in cultures of adult cells. K13 expression was greater in cultures grown with physiologic calcium concentrations (1.2 mM) than in those grown at 0.15 mM or less. Our findings are consistent with basal-like characters of these cells in 0.15 mM calcium growth conditions. Differentiation of fetal oral cells in culture to the suprabasal basal cell stage in 1.2 mM Ca2+ is shown by the expression of K13.

[Normal human gingiva. In vitro observations]. / Gengiva normale umana. Osservazioni in vitro.

By comparing human embrional gum fragments cultivated in vitro using the technique of Wolff and Haffen with adult gum fragments, the advantages of the fetal gum are evident; and this could serve as a point of departure for an analysis of the differentiation and the cytophysiology of this structure, which is still not very well known.

Numerical frequency of epithelial abnormalities, particularly microkeratocysts, in the developing human oral mucosa.

Clinically manifest gingival and median palatal cysts in the adult are relatively rare lesions. The present study using Epon-embedded material and serial paraffin sections of fifty-five human heads, approximately 8 to 22 weeks of fetal age, demonstrated that (1) dental lamina-derived microkeratocysts develop and increase in number from the twelfth to the twenty-second week, with a maximum of 190 cysts per fetus; (2) midpalatal microkeratocysts reach a peak number of below 20 per fetus at week 14 and do not become more numerous with time. In addition, morphologic findings offer evidence of fetal cyst development through differentiation phenomena and reconfirm the discharge mechanism responsible for cyst disappearance. It appears that cyst development through epithelial differentiation is an essential step if it is to be at all possible for discharge to occur. Most microcysts of the alveolar crest and the midpalatal region are apparently discharged shortly after birth, therefore, the respective cysts in the adult are rare.