The role of MAPK signaling pathway in formation of EMT in oral squamous carcinoma cells induced by TNF-α.

To study the role of MAPK signaling pathway in the development of Epithelial-mesenchymal transition in oral squamous cell carcinoma induced by inflammatory factor TNF-α. After the action of TNF-α, the expression of JNK, ERK, P38 in MAPK signaling pathway increased and the expression of E-cadherin, Claudin1 decreased significantly compared to the normal control group. After the addition of corresponding inhibitor, the expression of JNK, ERK, P38 decreased and the expression of E-cadherin, Claudin1 increased compared with TNF-α group.

Conformational changes in the rod domain of human keratin 8 following heterotypic association with keratin 18 and its implication for filament stability.

Keratin intermediate filaments are heteropolymers of type I and type II polypeptides that constitute the bulk of the epithelial cytoskeleton. We microinjected seven keratin monoclonal antibodies into human epithelial cells, and two of them, only A45-B/B3 and LP3K, caused the formation of keratin aggregates. The keratin filaments in human epithelial cells were also disrupted by a monovalent A45-B/B3 Fab fragment, suggesting that the binding of the antibody, rather than cross-linking, collapses the filaments.

An immunohistochemical study of keratin expression in ameloblastoma from a Kenyan population.

Objectives: Ameloblastomas appear to exhibit biological heterogeneity and, except in the case of malignancy, histological appearances that do not always allow their behaviour to be predicted. The aim of this study was to assess keratin expression in African ameloblastomas and to correlate this with their clinical and histological features.

Materials And Methods: Expression of simple keratins 7, 8, 18 and 19; cornification keratins 1 and 10; basal and differentiation keratins 5 and 14 and hyperproliferation-related keratins 6 and 16 in 14-39 cases of ameloblastoma was assessed by immunohistochemical methods.

Regulation of PAMP and adrenomedullin receptor expression in the rat adrenal zona glomerulosa.

Two peptide hormones are produced from the precursor peptide pre-proadrenoemdullin, known to be expressed in rat zona glomerulosa cells. Receptors for both adrenomedullin and pro-adrenomedullin N-terminal 20 peptide (PAMP) have been identified in the rat adrenal cortex but there is no information to date about the regulation of expression of these receptors, and the significance of these peptides in the regulation of adrenocortical function. In the present study the effects of dietary sodium changes on PAMP and adrenomedullin receptor expression was investigated.

Direct effects of corticotrophin on oral keratinocyte cell proliferation.

Corticotropin is produced by keratinocytes and may have an immunoregulatory role in oral mucosa and skin. We have investigated its effects on a human oral keratinocyte cell line and shown that corticotropin, acting via its specific receptor, stimulates a dose-dependent increase in DNA synthesis and induces cell proliferation. When cells were incubated in the presence of increasing concentrations of corticotropin, there were significant increases in intracellular cAMP levels.

Protease-activated receptors and their role in IL-6 and NF-IL-6 expression in human gingival fibroblasts.

The serine protease thrombin is formed at sites of coagulation and inflammation and has been shown to have important proinflammatory cellular effects relevant to the pathogenesis of periodontal disease. Thrombin acts via specific cell surface receptors termed protease-activated receptor-1 (PAR-1) and PAR-3, which have a distinctive method of activation. Proteolytic cleavage of the extracellular domain by thrombin reveals a hidden amino terminus which then acts as a "tethered ligand".

Bromodeoxyuridine incorporation and Ki 67 expression in oral hairy leukoplakia.

Objectives: Oral hairy leukoplakia (HL) is an acanthotic, hyperparakeratotic lesion characterised by the presence of a replicative Epstein-Barr virus (EBV) infection in the superficial and adjoining layers of the epithelium. EBV or its gene products are capable of modifying epithelial differentiation. The aim of this study was to establish whether the presence of EBV was associated with an alteration in cell turnover by assessing bromodeoxyuridine (BrdU) incorporation and Ki 67 expression in lesional tissue and control mucosa.

Adrenomedullin has mitogenic effects on human oral keratinocytes: involvement of cyclic AMP.

The effects of the novel vasoactive regulatory peptide, adrenomedullin, on human oral keratinocytes was investigated. Adrenomedullin, acting via its specific receptor, stimulated a dose-dependent increase in DNA synthesis, and, in addition, stimulated further changes in the cell cycle resulting in the proliferation of keratinocytes. When cells were incubated in the presence of increasing concentrations of adrenomedullin, there was a rapid and dose-dependent rise in intracellular cyclic AMP levels.