OBJECTIVETo investigate the effects of D-galactose (D-gal) on aging of rat marrow mesenchymal stem cells (MSCs) and its mechanism.

METHODSMSCs isolated from young (7 d) SD rats were randomly divided into four groups:control group, 1g/L, 10g/L and 50g/L D-gal treatment groups. In control group MSCs were cultured in DMEM containing 10% FBS for 48 h. In the D-gal treatment groups, MSCs were cultured in DMEM containing 10% FBS with 1g/L, 10g/L or 50g/L D-gal for 48 h. The senescence-associated changes were examined with SA-β-galactosidase (SA-β-gal) staining, the expressions of p53, p21 and p16 were detected by Western blot. The living and apoptotic cells were determined by AO/EB staining. Cell proliferation was detected by MTT assay. SOD activity was measured by xanthine oxidase method, and the MDA content was estimated with thiobarbituric acid (TBA) method.

RESULTSCompared to control group, the number of SA-β-gal positive cells and the expression of p53, p21 and p16 were significantly increased in the 10g/L and 50g/L D-gal treatment groups. The apoptosis rate in 50g/L D-gal group was significantly higher than that in control group (P<0.01). The proliferation of MSCs was decreased in the 10g/L and 50g/L D-gal groups compared to control group (P<0.05). After 10g/L and 50g/L D-gal treatment, SOD activity was significantly decreased (P<0.01), and MDA level was increased (P<0.01).

CONCLUSIONThe aging of MSCs can be induced by 10g/L and 50g/L D-gal, which may be associated with the elevated levels of oxidative stress.