ABSTRACT
We investigated changes in oxidative biomarkers in brain regions such as brainstem, cerebellum, and cerebral cortex of 3-, 6-, 18-, 24-, and 30-month-old rats. We also assessed the effects of low-intensity exercise on these biomarkers in these regions of 6-, 18-, and 24-month-old rats that started exercise on a treadmill at 3, 15, and 21 months of age, respectively. Radiographic images of the femur were taken for all rats. A total of 25 rats (age: twelve 6-, ten 18-, ten 24-, and three 30-month-old rats) were used. Lipid hydroperoxide levels increased in cerebellum at 18 months. Total antioxidant activity exhibited lowest values in brainstem at 3 months. Superoxide dismutase activity did not exhibit significant changes during aging. Total thiol content exhibited lowest values in brain regions of 24- and 30-month-old rats. Exercise reduced total thiol content in brainstem at 6 months, but no change occurred in other regions and other ages. Femur increased its length and width and cortical thickness with advancing age. No change occurred in medullary width. Radiolucency increased and sclerosis was found in cortical and medullary bone with advancing age. Exercise reduced radiolucency and medullary sclerosis. Therefore, aging differentially changed oxidative biomarkers in different brain regions and radiographic measures of the femur. Low-intensity exercise only ameliorated some radiographic measurements of femur. Since the present study possessed limitations (small number of rats per group), a beneficial effect of regular low-intensity exercise on oxidative markers in brain cannot be ruled out.
Subject(s)
Animals , Male , Rats , Physical Conditioning, Animal/physiology , Brain/metabolism , Aging/physiology , Oxidative Stress/physiology , Femur/diagnostic imaging , Lipid Peroxides/analysis , Oxidation-Reduction , Aging/metabolism , Biomarkers/analysis , Lipid Peroxidation , Rats, Wistar , Femur/chemistryABSTRACT
O objetivo deste estudo foi avaliar a expressão da enzima aldeído desidrogenase (ALDH), assim como dos marcadores de membrana celular STRO-1 e CD44 em células-tronco da polpa de dentes decíduos (SHEDs), permanentes (DPSCs) e fibroblastos da polpa (HDPFs), através da citometria de fluxo e do western blot. Para tanto, as células foram cultivadas em meio DMEM/ HEPES, suplementado com soro fetal bovino a 10%, 100U/mL de penicilina, 100µg/mL de estreptomicina e armazenadas em estufa a 37ºC e 5% de CO2. Para a avaliação dos resultados da citometria de fluxo foram utilizados o teste não paramétrico de Kruskal-Wallis (p ≤ 0,05) e o teste de comparação múltipla de Dunn. As três linhagens de células, quando caracterizadas pelo western blot, expressaram fortemente a ALDH, assim como o STRO-1, ao passo que apresentaram uma fraca expressão para o CD44, não apresentando diferença na intensidade das bandas entre as mesmas. Já na análise por citometria de fluxo, todas as células apresentaram valores percentuais altos para o CD44, sem diferença estatística. Para o marcador STRO-1, os valores foram relativamente baixos para os três tipos celulares, havendo diferença apenas entre SHEDs e HDPFs. Os valores percentuais para a atividade da enzima ALDH foram igualmente baixos, havendo diferença estatisticamente significante entre DPSCs e HDPFs. Os resultados deste estudo sugerem que SHEDs, DPSCs e fibroblastos podem compartilhar algumas características, como a expressão de determinados marcadores genéticos. Da mesma forma, indicam que o uso da ALDH pode ser explorado em pesquisas futuras, para caracterização e seleção das MSCs.
The aim of this study was to evaluate the aldehyde dehydrogenase (ALDH) activity, as well as the expression of STRO-1 and CD44 in pulp stem cells from deciduous (SHEDs) and permanent (DPSCs) teeth, as well in pulp fibroblasts, by flow cytometry and western blot. For this purpose, cells were cultured in DMEM/ HEPES, supplemented with fetal bovine serum at 10%, 100U/ml of penicillin, 100µg/mL streptomycin and stored at 37°C and 5% CO2. To verify differences in the flow cytometry analysis between the three cell types, the nonparametric Kruskal-Wallis test was used (p ï£ 0,05), along with the Dunn multiple comparison test. In the western blot test, all the cell lineages strongly expressed ALDH, as well as STRO-1, while they presented a weak expression for CD44. There were no differences in the band intensity between the three cell types for the proteins tested. In the flow cytometry analysis, all cells showed high percentages of CD44, with no statistical difference. For the STRO-1 marker, the values were relatively low for all the three cell types, and differences were observed just between SHEDs and HDPFs. The values observed for the ALDH activity were also lower, with statistically significant difference between DPSCs and HDPFs. The results of this study suggest that SHEDs, DPSCs and pulp fibroblasts may share some important characteristics, such as the expression of certain genetic markers. Likewise, indicate that the use of ALDH activity can be exploited in future research for identification and characterization of MSCs.