Inhibition of mircoRNA-34a Enhances Survival of Human Bone Marrow Mesenchymal Stromal/Stem Cells Under Oxidative Stress
Yang Liu, Xiaohu Zhang, Jie Chen, Tingyu Li
Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China (mainland)
Med Sci Monit 2018; 24: LBR264-271
Available online: 2018-01-13
Mesenchymal stromal/stem cells (MSCs) are broadly used for many diseases, but the efficacy of MSC engraftment is very low due to low viability and high cell death rate under a stressful microenvironment. The present study aimed to investigate whether microRNA-34a (miR-34a), which is a downstream target of P53, is involved in H2O2-induced MSC cell death.
MATERIAL AND METHODS: Human bone marrow MSCs (hMSCs) were purchased from Lonza and were cultured as previously described. hMSCs were transfected with miR-34a inhibitor and exposed to H2O2. Cell proliferation assay was used to assess the survival rate of hMSCs. Real-time PCR and Western blot analysis were used to examine proliferation and survival ability of hMSCs.
RESULTS: H2O2 exposure significantly increased miR-34a expression in human bone marrow MSCs. H2O2 challenge induced massive MSC cell death along with reduction of expression of proliferation marker Ki67 and survival-related genes Bcl-2 and Survivin. Transfection of miR-34a inhibitor anti-34a led to a significant protective effect and rescued MSC cell death triggered by H2O2 exposure by 50%. Moreover, anti-34a dramatically increased Bcl-2 and Ki67 mRNA expression levels by over 10-fold compared to the mock control group under H2O2 exposure. The protein levels of Bcl-2 and Survivin were also rescued by anti-34a treatment by 50%.
CONCLUSIONS: Our results suggest that miR-34a plays a key role in oxidative stress-induced MSC cell death, and targeting miR-34a might be a promising strategy to enhance the survival rate of engrafted stem cells, which may improve therapeutic outcome.
Keywords: mesenchymal stromal cells, Oxidative Stress