Cell survival evaluation of mesenchaymal stem cells cultivated in the presense of secretome of HIF-1α/Nrf2-engineered-MSC

Mesenchymal Stem Cells (MSCs) are the ideal cell source for transplantation. But different stresses during MSCs in vitro expansion lead to decreased survival rate after transplantation. Therefore, applying practical strategies to enhance their viability in stressful microenvironment is quite necessary. This study aimed to survey effects of HIF-1&alpha-Nrf2-engineered-MSCs secretome on MSCs survival under different stress conditions. Recombinant pcDNA3.1-Nrf2 and pcDNA3.1-HIF-1&alpha were transfected and co-transfected into umbilical cord MSCs (UC-MSCs) using FUGENE HD transfection reagent. After 72 hrs, expression of Nrf2 and HIF-1&alpha were verified by RT-PCR. Different cell groups were exposed to hypoxic, serum deprived and oxidative stress conditions. The HIF-1&alpha-Nrf2-engineered-MSCs secretome was harvested and concentrated. Then, UC-MSCs were cultured in presence of this secretome and their viability was assayed using trypan blue exclusion dye and WST-1 flowing by induction of the same stress conditions. HIF-1&alpha-Nrf2-engineered-MSCs expressed Nrf2 and HIF-1&alpha. HIF-1&alpha-Nrf2-engineered-MSCs indicated a higher survival rate (84.5 ± 5.5%) compared with the control group (55.3 ± 4%). Moreover, the survival rate of UC-MSCs cultured with HIF-1&alpha-Nrf2-engineered-MSCs secretome was 81.6 ± 6% and it was 57.9 ± 4.3% for the control group under the same stress conditions. HIF-1&alpha-Nrf2-engineered-MSCs secretome protects MSCs against oxidative, serum deprived and hypoxic stress conditions.