Expression of Neurotrophins in Adipose-derived Stem Cells during in vitro Culture and Posttransplantation in Parkinsonian Rat Model

Background: Adipose tissue stem cells (ASCs) cause faster repair of damaged tissue posttransplantation by releasing growth factors in neurodegenerative diseases. ASCs secrete factors in the culture medium called conditioned medium (CM) in vitro. This study investigated the expression of neurotrophin genes in vitro culture and transplant of ASCs in Parkinsonian rats. Materials and Methods: In this study, expression of neurotrophin genes was investigated in vitro and in vivo. In vitro means evaluating expression of genes in the conditioned medium from 21-day culture of ASCs (culture group) and the transplantation group, which were divided into subgroups of Parkinsonian rat model receiving ASCs (Cell group), and another group reveiving cells and conditioned medium (Cell + Conditioned Medium group). The sham groups were designed with Parkinsonian model and sham animals injected respectively with 6-OHDA (neurotoxin) and normal saline (neurotoxin solvent) instead of neurotoxin. All the injections were performed stereotaxically into the right striatum. After eight weeks of treatment, the transplantation areas were isolated and stored at -70 °C. Then, the exression of neurotrophin (BDNF, NT3 and NGF) mRNAs was analyzed. Results: BDNF and NT3 mRNA expression levels were significantly higher in the cells+conditioned medium and cell, as compared with the culture group. A significant decrease in NT3 gene expression in cell group was observed compared to that of cell group + conditional medium. NGF expression of the culture and cell groups showed a significant decrease compared to the cell+conditional medium group. Conclusion: In vitro cultured ASCs cannot significantly induce expression of neurotrophin genes, but when the cells are transplanted along with secretions (conditional medium) at the site of injury, the microenvironment of the transplantation site can induce higher expressions of neurotrophins. These cells will be good candidates for cell therapy.