[Effects of resveratrol on aging of mesenchymal stem cells and its mechanism].

OBJECTIVE: To investigate the effects of resveratrol (Res) on aging of marrow mesenchymal stem cells (MSCs), and to explore its mechanism. METHODS: MSCs were isolated from young SD rats and cultured in vitro. The optimal D-gal concentration for induction of MSCs senescence was determined. Then MSCs were randomly divided into four groups, namely the control group, 10µmol/L, 50µmol/L and 100µmol/L Res groups. After the cells were treated with different concentration of Res for 48 h, the senescence-associated changes were examined with senescence-associated-ß-galactosidase (SA-ß-gal) staining; the expression of p53, p16 and γ-H2AX was evaluated by Western blot. The total active oxygen species (ROS) level was determined by flow cytometry with DCFH-DA staining. In order to assess the effect of Res on the mitochondrial function, MitoSox Red staining was used to detect mitochondrial ROS levels in each group, mitochondrial membrane potential was detected by JC-1 assay, mPTP method was used to detect mitochondrial membrane channel opening level, and Western blot was used to detect the expression level of cytoplasmic cytochrome C (Cyt-C). RESULTS: D-gal 10 and 50 g/L significantly increased the number of SA-ß-gal positive cells and the level of mitochondrial ROS (all P<0.01). Therefore, 10 g/L D-gal was used to induce the senescence of MSCs in subsequent experiment. Compared with the control group, the number of SA-ß-gal positive cells in Res groups significantly decreased (all P<0.01), the expression of p53, p16 and γ-H2AX decreased, and the total and mitochondrial ROS level also decreased (all P<0.01). Moreover, mitochondrial membrane potential, open level of mitochondrial membrane channels and the levels of cytoplasm Cyt-C in the Res treatment groups decreased compared with the control group (P<0.05 or P<0.01). CONCLUSIONS: Resveratrol can protect the mitochondrial function of MSCs, and effectively delay the MSC senescence.

High glucose induces the aging of mesenchymal stem cells via Akt/mTOR signaling.

It has previously been demonstrated that glucose is important in the process of stem cell aging. However, the mechanisms of cell senescence induced by high glucose (HG) remain to be elucidated. The preliminary study indicated that D­galactose induced mesenchymal stem cell (MSCs) aging. The present study demonstrated, following treatment with 11.0 or 22.0 mM HG for 14 days, that HG significantly promoted MSCs aging and the expression levels of phosphorylated (p-)phosphatidylinositol 3-kinase/protein kinase B (Akt) and p­mammalian target of rapamycin signaling (mTOR) in the HG groups were increased compared with the control group. However, following Akt inhibition with 1.0 or 10.0 nM MK­2206, which is an Akt­specific small molecule inhibitor, the senescence­cell value in the HG group was significantly decreased compared with the control group. These results indicated that HG induced MSCs senescence and this effect was primarily mediated via the Akt/mTOR signaling pathway.