Navegando por Palavras-chave "fibroblasts"

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    Control of the skin scarring response
    (Academia Brasileira de Ciências, 2009-09-01) Ferreira, Lydia Masako [UNIFESP]; Gragnani, Alfredo [UNIFESP]; Furtado, Fabianne [UNIFESP]; Hochman, Bernardo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    There comes a time when the understanding of the cutaneous healing process becomes essential due to the need for a precocious tissue repair to reduce the physical, social, and psychological morbidity. Advances in the knowledge on the control of interaction among cells, matrix and growth factors will provide more information on the Regenerative Medicine, an emerging area of research in medical bioengineering. However, considering the dynamism and complexity of the cutaneous healing response, it is fundamental to understand the control mechanism exerted by the interaction and synergism of both systems, cutaneous nervous and central nervous, via hypothalamus hypophysis-adrenal axis, a relevant subject, but hardly ever explored. The present study reviews the neuro-immune-endocrine physiology of the skin responsible for its multiple functions and the extreme disturbances of the healing process, like the excess and deficiency of the extracellular matrix deposition.
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    Dimethylaminoethanol affects the viability of human cultured fibroblasts
    (Springer, 2007-12-01) Gragnani, Alfredo [UNIFESP]; Giannoccaro, Fabiana Bocci; Sobral, Christiane Steponavicius [UNIFESP]; Franca, Jeronimo Pereira de [UNIFESP]; Ferreira, Lydia Masako [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Background: in clinical practice, dimethylaminoethanol (DMAE) has been used in the fight against wrinkles and flaccidity in the cervicofacial region. the firming action of DMAE is explained by the fact that its molecule, considered to be a precursor of acetylcholine, alters muscle contraction. However, no experimental studies have confirmed this theory. Because the actual mechanism of DMAE action was not defined and there were no references in the literature regarding its direct action on fibroblasts, this study was performed to evaluate the direct action of DMAE on cultured human fibroblasts.Methods: Human fibroblasts obtained from discarded fragments of total skin from patients undergoing plastic or reconstructive surgical procedures performed within the Plastic Surgery Division at the Federal University of S (a) over tildeo Paulo were used for this study. the explant technique was used. the culture medium was supplemented with different concentrations of DMAE on the fourth cell passage, and the cell proliferation rate, cytosolic calcium levels, and cell cycle were evaluated. Statistical analysis was performed using analysis of variance (ANOVA) followed by a New-man-Keuls test for multiple comparisons.Results: A decrease in fibroblast proliferation was associated with an increase in DMAE concentration. A longer treatment time with trypsin was required for the groups treated with DMAE in a dose-dependent manner. in the presence of DMAE, cytosolic calcium increased in a dose-dependent manner. Apoptosis also increased in groups treated with DMAE.Conclusion: Dimethylaminoethanol reduced the proliferation of fibroblasts, increased cytosolic calcium, and changed the cell cycle, causing an increase in apoptosis in cultured human fibroblasts.
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    Keloid explant culture: a model for keloid fibroblasts isolation and cultivation based on the biological differences of its specific regions
    (Wiley-Blackwell, 2010-10-01) Tucci-Viegas, Vanina Monique [UNIFESP]; Hochman, Bernardo [UNIFESP]; Franca, Jeronimo P. [UNIFESP]; Ferreira, Lydia M. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    In vitro studies with keloid fibroblasts frequently present contradictory results. This may occur because keloids present distinct genotypic and phenotypic characteristics in its different regions, such as the peripheral region in relation to the central region. We suggest an explant model for keloid fibroblasts harvesting, standardising the initial processing of keloid samples to obtain fragments from different regions, considering its biological differences, for primary cell culture. the different keloid regions were delimited and fragments were obtained using a 3-mm diameter punch. To remove fragments from the periphery, the punch was placed in one longitudinal line extremity, respecting the lesion borders. for the central region, it was placed in the intersection of lines at the level of the largest longitudinal and transversal axes, the other fragments being removed centrifugally in relation to the first one. Primary fibroblast culture was carried out by explant. Flow cytometry analysis showed cell cycle differences between the groups, confirming its different origins and biological characteristics. in conclusion, our proposed model proved itself efficient for keloid fibroblast isolation from specific regions and cultivation. Its simplicity and ease of execution may turn it into an important tool for studying the characteristics of the different keloid-derived fibroblasts in culture.
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    Vitamin E prevents cell death induced by mild oxidative stress in chicken skeletal muscle cells
    (Elsevier B.V., 2005-07-01) Nunes, Viviane A. [UNIFESP]; Gozzo, Andrezza Justino [UNIFESP]; Cruz-Silva, Ilana [UNIFESP]; Juliano, Maria Aparecida [UNIFESP]; Viel, Tania A. [UNIFESP]; Godinho, Rosely O. [UNIFESP]; Meirelles, Flavio V.; Sampaio, Misako U. [UNIFESP]; Sampaio, Claudio A M [UNIFESP]; Araujo, Mariana S. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    Apoptosis and necrosis are two forms of cell death that can occur in response to various agents and oxidative damage. in addition to necrosis, apoptosis contributes to muscle fiber loss in various muscular dystrophies as well participates in the exudative diathesis in chicken, pathology caused by dietary deficiency of vitamin E and selenium, which affects muscle tissue. We have used chicken skeletal muscle cells and bovine fibroblasts to study molecular events involved in the cell death induced by oxidative stress and apoptotic agents. the effect of vitamin E on cell death induced by oxidants was also investigated. Treatment of cells with anti-Fas antibody (50 to 400 ng/mL), staurosporine (0.1 to 100 mu M) and TNF-alpha (10 and 50 ng/mL) resulted in a little loss of Trypan blue exclusion ability. Those stimuli conducted cells to apoptosis detected by an enhancement in caspase activity upon fluorogenic substrates but this activity was not fully blocked by the caspase inhibitor Z-VAD-fmk. Oxidative stress induced by menadione (10, 100 and 250 mu M) promoted a significant reduction in cell viability (10%, 20% and 35% for fibroblasts; 20%, 30% and 75% for muscle cells, respectively) and caused an increase in caspase activity and DNA fragmentation. H2O2 also promoted apoptosis verified by caspase activation and DNA fragmentation, but in higher doses induced necrosis. Vitamin E protected cells from death induced by low doses of oxidants. Although it was ineffective in reducing caspase activity in fibroblasts, this vitamin diminished the enzyme activity in muscle cells. These data suggested that oxidative stress could activate apoptotic mechanisms; however the mode of cell death will depend on the intensity and duration of the stimulus, and on the antioxidant status of the cells. (C) 2005 Elsevier Inc. All rights reserved.