ABSTRACT
Objective: Mesenchymal stem cells [MSC] from various sources have the potentials to positively affect regenerative medicine.Furthermore, pre-conditioning strategies with different agents could improve the efficacy of cell therapy. This study compares the effects of an anti-inflammatory and antioxidant agent, melatonin, on protection of bone marrow-derived MSCs [BMSCs] and adipose tissue-derived MSCs [ADSCs]
Materials and Methods: In this experimental study, rat BMSCs and ADSCs were isolated and expanded. Pre-conditioning was performed with 5 ìM melatonin for 24 hours. Cell proliferation and viability were detected by MTT assay. Expression of BAX, BCL2, melatonin receptors and osteocalcin genes were evaluated by reverse transcriptase-polymerase chain reaction [RT-PCR]. Also, apoptosis was detected with tunnel assay. Osteogenic differentiation was analyzed using alizarin red staining
Results: No significant increase was found in cell viability between BMSCs and ADSCs after melatonin preconditioning. Following melatonin preconditioning, BAX expression was significantly down-regulated in both ADSCs and BMSCs [P<0.05], with the difference being more significant in ADSCs compared to BMSCs. BCL2 expression was increased significantly in both cell types after preconditioning. Metalothionine 1 and Metalothionine 2 were both upregulated significantly in the two cell types [P<0.05]. Melatonin increased osteogenesis capability through increasing osteocalcin expression. However, expression of osteocalcin in BMSCs before and after preconditioning was higher than that in ADSCs. On the other hand, melatonin expression in ADSCs was in higher levels than in BMSCs. Melatonin also improved alizarin red concentration significantly in both BMSCs and ADSCs [P<0.05]. Alizarin red staining severity increased significantly in ADSCs after preconditioning compared to BMSCs [P<0.05]
Conclusion: Here we have shown that the effects of preconditioning on melatonin expression in ADSCs are higher than those in BMSCs. These findings could be used in adoption of a proper preconditioning protocol based on the sources of MSCs in specific clinical applications, especially in bone regeneration
ABSTRACT
Objective: Bone marrow [BM] is one of the major hematopoietic organs in postnatal life that consists of a heterogeneous population of stem cells which have been previously described. Recently, a rare population of stem cells that are called very small embryonic-like [VSEL] stem cells has been found in the BM. These cells express several developmental markers of pluripotent stem cells and can be mobilized into peripheral blood [PB] in response to tissue injury. In this study we have attempted to investigate the ability of these cells to migrate toward an injured spinal cord after transplantation through the tail vein in a rat model
Materials and Methods: In this experimental study, VSELs were isolated from total BM cells using a fluorescent activated cell sorting [FACS] system and sca1 and stage specific embryonic antigen [SSEA-1] antibodies. After isolation, VSELs were cultured for 7 days on C2C12 as the feeder layer. Then, VSELs were labeled with 1,1´-dioctadecyl-3,3,3´,3´- tetramethylindocarbocyanine perchlorate [DiI] and transplanted into the rat spinal cord injury [SCI] model via the tail vein. Finally, we sought to determine the presence of VSELs in the lesion site
Results: We isolated a high number of VSELs from the BM. After cultivation, the VSELs colonies were positive for SSEA-1, Oct4 and Sca1. At one month after transplantation, real-time polymerase chain reaction analysis confirmed a significantly increased expression level of Oct4 and SSEA-1 positive cells at the injury site
Conclusion: VSELs have the capability to migrate and localize in an injured spinal cord after transplantation