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
Mesenchymal stem cells [MSCs] are undifferentiated cells that can differentiate and divide to other cell types. Transplantation of these cells to the different organs is used for curing various diseases. The aim of this research was whether MSCs transplantation could treat the sterile testes. In this experimental study, Donor MSCs were isolated from bone marrow of Wistar rats. The recipients were received 40 mg/kg of busulfan to stop endogenous spermatogenesis. The MSCs were injected into the left testes. Cell tracing was done by labeling the MSCs by 5-Bromo-2- Deoxy Uridine [BrdU]. The immunohistochemical and morphometrical studies were performed to analysis the curing criteria. The number of spermatogonia [25.38 +/- 1.57], primary spermatocytes [55.41 +/- 1.62] and spermatozoids [4.95 +/- 1.30]x10[6] in busulfan treated animals were decreased significantly as compared to the control group [33.35 +/- 1.78, 64.44 +/- 2.00] and [10.50 +/- 1.82]x10[6] respectively but stem cells therapy help the spermatogenesis begin more effective in these animals [32.78 +/- 1.99, 63.59 +/- 2.01] and [9.81 +/- 1.33]x10[6] respectively than the control group. The injected BrdU labeled mesenchymal stem cells differentiated to spermatogonia and spermatozoa in the seminiferous tubules of the infertile testis and also to the interstitial cells between tubules. We concluded that testis of host infertile rats accepted transplanted MSCs. The transplanted MSCs could differentiate into germinal cells in testicular seminiferous tubules