Résumé
Objective: this study examined the in vivo differentiation of mesenchymal stem cells [MSCs] into insulin producing cells [IPCs] on electrospun poly-L-lactide acid [PLLA] scaffolds coated with Matricaria chammomila L. [chamomile] oil
Materials and Methods: in this interventional, experimental study adipose MSCs [AMSCs] were isolated from 12 adult male New Zealand white rabbits and characterized by flow cytometry. AMSCs were subsequently differentiated into osteogenic and adipogenic lines. Cells were seeded onto either a PLLA scaffold [control] or PLLA scaffold coated with chamomile oil [experimental]. A total of 24 scaffolds were inserted into the pancreatic area of each rabbit and placement was confirmed by ultrasound. After 21 days, immunohistochemistry analysis of insulin-producing like cells on protein levels confirmed insulin expression of insulin producing cells [IPSCs].Real-time polymerase chain reaction [PCR] determined the expressions of genes related to pancreatic endocrine development and function
Results: fourier transform infrared spectroscopy [FTIR] results confirmed the existence of oil on the surface of the PLLA scaffold. The results showed a new peak at 2854 cm[-1] for the aliphatic CH[2] bond. Pdx1 expression was 0.051 +/- 0.007 in the experimental group and 0.009 +/- 0.002 in the control group. There was significantly increased insulin expression in the scaffold coated with chamomile oil [0.09 +/- 0.001] compared to control group [0.063 +/- 0.009, P
Conclusion: the pancreatic region is an optimal site for differentiation of AMSCs to IPCs. Chamomile oil [as an antioxidant agent] can affect cell adhesion to the scaffold and increase cell differentiation. In addition, the oil may lead to increased blood glucose uptake in pathways in the muscles, liver and fatty tissue of a diabetic animal model by some probable molecular mechanisms
Résumé
Reconstructed embryos from terminally differentiated somatic cells have revealed high levels of genomic methylation which results in inappropriate expression patterns of imprinted and non-imprinted genes. These aberrant expressions are probably responsible for different abnormalities during the development of clones. Improvement in cloning competency may be achieved through modification of epigenetic markers in donor cells. Our objective was to determine if treatment of donor cells for 72 hours with 5-aza-2'-deoxycytidine [5-aza-dc; 0-0.3 microM], a DNA methyl transferase inhibitor, improved development and expression of Oct-4. In comparison with untreated cells, 0.01 and 0.08 microM 5-aza-dc treated cells insignificantly decreased the blastocyst rate [32.1% vs. 28.6% and 27.2%, respectively] while it was significant for 0.3 microM treated cells [6.5%]. Embryo quality as measured by the total cell number [TCN] decreased in a dose-related fashion, which was significant at 0.08 and 0.3 microM 5-aza-dc treated cells when compared with 0 and 0.01 microM 5-aza-dc treated cells. Although reconstructed embryos from 0.08 and 0.3 microM 5-aza-dc treated cells showed lower levels of DNA methylation and histone H3 acetylation, development to blastocyst stage was decreased. The epigenetic markers of embryos cloned from 0.01 microM 5-aza-dc remained unchanged. These results show that 5-aza-dc is not a suitable choice for modifying nuclear reprogramming. Finally, it was concluded that the wide genomic hypomethylation induced by 5-aza-dc deleteriously impacts the developmental competency of cloned embryo