ABSTRACT
BACKGROUND: Glucose-derived metabolites may alter the structure and biologic properties of important proteins in periodontium, such as collagens. As a consequence, it is possible that collagen-binding cells may change their phenotypic traits. Although the glucose-derived product methylglyoxal (MGO) has been detected in periodontal lesions, the precise effect of collagen glycation on gingival connective tissue biology is not fully understood. The present study evaluates whether collagen glycation by MGO may affect phenotypic properties and remodeling capacity of human gingival fibroblasts (HGFs). METHODS: Primary cultures of HGFs were grown on Type I collagen matrices previously treated with MGO. Cell cultures were tested for cell viability, apoptosis, α-smooth muscle actin (SMA), fibronectin (FN) production, and collagen remodeling. Mechanical properties and morphology of MGO-treated collagen gels were evaluated using rheometry and atomic force microscopy. Statistical analysis was performed by Kruskal-Wallis and Mann-Whitney U tests. RESULTS: MGO-treated collagen did not affect cell viability or apoptosis. In addition, MGO did not induce significant changes in morphology or mechanical properties of the collagen matrix. However, MGO-treated collagen stimulated an increase in the myofibroblast marker α-SMA, production and assembly of FN, and contraction of collagen matrices. Moreover, use of a triple-helical peptide that reconstitutes the collagen-binding domain for integrins GFOGER reverted the assembly of FN induced by MGO-treated collagen. CONCLUSIONS: The present study shows that collagen glycation by MGO stimulates differentiation of myofibroblasts and production and assembly of FN. These responses may alter the homeostatic balance and wound-healing response of gingival connective tissues affected by diabetes mellitus or aging.
Subject(s)
Cell Differentiation/drug effects , Collagen/metabolism , Collagen/pharmacology , Gingiva/cytology , Myofibroblasts/drug effects , Pyruvaldehyde/pharmacology , Actins/metabolism , Apoptosis , Biomarkers/metabolism , Cell Survival , Cells, Cultured , Fibronectins/metabolism , Humans , Microscopy, Atomic Force , Myofibroblasts/metabolism , Myofibroblasts/physiology , PhenotypeABSTRACT
BACKGROUND: Differences in immune profile between actinic cheilitis (AC), a precursor of lip squamous cell carcinoma, and normal lip vermillion (NL) have not been elucidated. OBJECTIVES: To compare density, distribution, and ratios of CD8+ and FoxP3+ cells between AC and NL and assess their associations with clinicopathologic variables. METHODS: Samples of AC and NL obtained between 2001 and 2013 at the College of Dentistry of the University of Concepcion, Chile, were retrospectively analyzed for immunohistochemical detection of CD8+ and FoxP3+ cells. Differences between groups were tested by Mann-Whitney U and Fisher's exact tests. Independent effects of cell densities and CD8/FoxP3 ratio with AC were assessed by multiple logistic regression analysis after adjustment for potential confounding. RESULTS: A total of 62 AC and 24 NL biopsies were included. Densities of CD8+ and FoxP3+ cells in AC were significantly higher than in NL. Conversely, the CD8+/FoxP3+ ratio was significantly lower in AC as compared to NL. After adjustment for sun exposure, age, gender, and smoking status, a stromal FoxP3+ cell density higher than 0.35 cells/field was significantly associated with increased odds of AC (odds ratio [OR] = 5.01, 95% confidence interval [CI]: 1.18-21.31), while a stromal CD8+/FoxP3+ ratio higher than 5.91 was associated with decreased odds of AC (OR = 0.29, 95% CI: 0.08-1.08). CONCLUSIONS: AC is characterized by increased FoxP3+ cell infiltration and a reduced CD8/FoxP3 ratio as compared to NL. Therefore, increased infiltration of FoxP3+ cells relative to CD8+ cells may contribute to the transition from normal to preneoplastic stages in lip carcinogenesis.
Subject(s)
CD8-Positive T-Lymphocytes/immunology , Carcinoma, Squamous Cell/immunology , Cheilitis/immunology , Forkhead Transcription Factors/analysis , Lip Neoplasms/immunology , Precancerous Conditions/immunology , Adult , Aged , Aged, 80 and over , Case-Control Studies , Cell Transformation, Neoplastic/immunology , Cheilitis/pathology , Female , Humans , Lip/immunology , Lymphocyte Count , Male , Middle Aged , Precancerous Conditions/pathology , Retrospective Studies , T-Lymphocytes/chemistry , T-Lymphocytes/immunology , Young AdultABSTRACT
El objetivo de este estudio fue evaluar el efecto de la radiación ultravioleta (UV) B sobre la expresión del factor de crecimiento transformante (TGF) ß1 por fibroblastos de mucosa oral, con el objetivo de dilucidar si este tipo celular puede contribuir a la expresión de TGFß1 en bermellón labial sobreexpuesto a la radiación UV. Se obtuvieron cultivos primarios de fibroblastos desde explantes de mucosa bucal, los que fueron irradiados con una dosis única de luz UVB (60 mJ/cm2). Se midió proliferación celular con el método MTT, y la expresión de TGFß1, a nivel de ARN mensajero (normalizado a GAPDH) por RT-PCR y a nivel de proteína mediante inmunofluorescencia. Se observó una disminución de la proliferación celular de los fibroblastos de mucosa oral a las 24 hrs post-irradiación en relación a los fibroblastos no irradiados (P<0,05, Mann Whitney). No se encontraron diferencias entre los fibroblastos control y los irradiados en la expresión de TGFß-1 ni a nivel de mensajero (0,5 y 6 h post-irradiación), ni de proteína (24 h post-irradiación). Los resultados sugieren que los fibroblastos de mucosa oral presentan una disminución de su proliferación en respuesta a una dosis única de radiación UVB, sin que se afecte la expresión de TGFß-1, la que fue similar a los fibroblastos no irradiados. Esto sugiere que los fibroblastos contribuirían a la producción de TGFß-1 en respuesta a la exposición crónica a UVB del bermellón labial.
The objective of this study was to characterize the effect of Ultraviolet (UV) B irradiation on the expression of transforming growth factor (TGF) ß1 by oral mucosa fibroblasts, in order to assess if these cells contribute to the production of TGFß-1 in UV-irradiated lip vermillion. Primary cultures of fibroblasts were obtained from oral mucosa explants, and were irradiated with a single dose of UVB light (60 mJ/cm2). The effects of UVB radiation on cell proliferation was evaluated by the MTT method. The effects of UVB on the expression of TGF-ß1 was analyzed by RT-PCR (normalized to GAPDH) and by immunofluorescence. The results showed a decrease in the proliferation of UVB-irradiated fibroblasts as compared to controls at 24h post-irradiation (p<0.05). No variations in the expression of TGFß1, both at the mRNA and protein level, were observed between control and UVB-irradiated fibroblasts during the first 24 h after irradiation. Oral mucosa fibroblasts have reduced proliferation in response to a single dose of UVB, but their expression of TGFß1 was not affected. This suggests that oral mucosa fibroblasts may contribute to the production of TGFß1 in the lip vermillion independent of UVB exposure.
