RESUMEN
Background: The regenerative capacity of the mammalian heart is quite limited. Recent reports have focused on reprogramming mesenchymal stem cells into cardiomyocytes. We investigated whether fibroblasts could transdifferentiate into myocardium
Methods: Mouse embryonic fibroblasts were treated with Trichostatin A [TSA] and 5-Aza-2-Deoxycytidine [5-aza-dC]. The treated cells were permeabilized with streptolysin O and exposed to the mouse cardiomyocyte extract and cultured for 1, 10, and 21 days. Cardiomyocyte markers were detected by immunohistochemistry. Alkaline phosphatase activity and OCT4 were also detected in cells treated by chromatinmodifying agents
Results: The cells exposed to a combination of 5-aza-dC and TSA and permeabilized in the presence of the cardiomyocyte extract showed morphological changes. The cells were unable to express cardiomyocyte markers after 24 h. Immunocytochemical assays showed a notable degree of myosin heavy chain and ?-actinin expressions after 10 days. The expression of the natriuretic factor and troponin T occurred after 21 days in these cells. The cells exposed to chromatin-modifying agents also expressed cardiomyocyte markers; however, the proportion of reprogrammed cells was clearly smaller than that in the cultures exposed to 5-aza-dC, TSA, and extract
Conclusion: It seems that the fibroblasts were able to eliminate the previous epigenetic markers and form new ones according to the factors existing in the extract. Since no beating was observed, at least up to 21 days, the cells may need an appropriate extracellular matrix for their function
RESUMEN
Following an early visual deprivation, the neural network involved in processing auditory spatial information undergoes a profound reorganization. In order to investigate this process, event-related potential provide accurate information about time course neural activation as well as perception and cognitive processes. In this study, the latency and amplitude of auditory P300 were compared in sighted and early blind individuals in age range of 18-25 years old. In this cross-sectional study, auditory P300 potential was measured in conventional oddball paradigm by using two tone burst stimuli [1000 and 2000 Hz] on 40 sighted subjects and 19 early blind subjects with mean age 20.94 years old. The mean latency of P300 in early blind subjects was significantly smaller than sighted subjects [p=0.00]. There were was no significant in amplitude between two groups [p > 0.05]. Reduced latency of P300 in early blind subjects in comparison to sighted subjects probably indicates the rate of automatic processing and information categorization is faster in early blind subjects because of sensory compensation. It seems that neural plasticity increases the rate of auditory processing and attention in early blind subjects