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Objective. To preliminary explore the senescent dynamic changes of the bone marrow mesenchymal stem cells (BMMSCs) by human ageing and its possible mechanism. Methods. The bone marrows were harvested from healthy volunteers, and according to volunteers’ age, these were divided into group A (≤25 years), group B (26-45 years), group C (46-65 years), and group D (>65 years). Totally, the bone marrows were extracted from the posterior superior iliac spine from volunteers under aseptic conditions. Diluted with isovolumic PBS, followed by centrifugation at 1×105/cm2, cells were cultured in a 5% CO2 incubator at 37°C. After three passages, surface marker identification of hBMMSCs was tested by flow cytometry (FCM), oil red O staining was used to observe the ability of osteogenic differentiation, alkaline phosphatase (ALP) staining and the levels of osteocalcin (OST) in the supernatants were used to observe the ability of adipogenic differentiation, senescence-associated β-galactosidase (SA-β-Gal) staining was used to detect the senescent BMSCs, the ability of BMSC proliferation was detected by cell counting kit-8 (CCK-8), the distribution of the cell cycle was analyzed by flow cytometry (FCM), and malondialdehyde (MDA) content, total glutathione peroxidase, total antioxidant capacity, and total superoxide dismutase (SOD) activity was analyzed using enzymatic assay. Results. The BMSCs highly expressed CD73 and CD90, but lowly expressed CD34 and CD19/CD14. With age, osteogenic differentiation was markedly increased and audiogenic differentiation was significantly decreased. The number of SA-β-gal-positive cells was significantly increased, the proliferation ability of hBMMSCs declined, the BMSCs were held in the G1 phase, the MDA level of BMSCs was significantly increased, and total glutathione peroxidase, total antioxidant capacity, and SOD activity significantly declined. Conclusions. With age, the aging BMSCs were intensified; the mechanism may be related to oxidative damage mediated aging-related pathways.

The present study investigated the effect and underlying mechanisms of ginsenoside Rg1 (Rg1) in attenuating subacute liver injury induced by D-galactose (D-gal) in mice. Specific Pathogen Free (SPF) male C57BL/6J mice were randomly divided into 3 groups: i) D-gal-administration group (D-gal group), where the mice were intraperitoneally administrated with D-gal (120 mg/kg/day for 42 days); ii) D-gal + Rg1 group where the mice were treated with 120 mg/kg/day D-gal for 42 days and with Rg1 at a dose of 20 mg/kg/day for 35 days. The first dose of Rg1 was administered on the 8th day of treatment with D-gal; and iii) the normal control group, where the mice were injected with an equal volume of saline for 42 days. The day following the final injections in all groups, peripheral blood was collected and serum was prepared to measure the contents of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBiL), advanced glycation end products (AGEs) and 8-hydroxy-2 deoxyguanosine (8-OH-dG). Liver tissue homogenates were prepared to measure the contents of malondialdehyde (MDA) and glutathione (GSH), and the activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). Paraffin section were prepared to observe the microscopic structure of the liver. Transmission electron microscopy was used to observe the ultrastructure of hepatocytes. Frozen section were prepared and stained with senescence-associated β-galactosidase to detect the relative optical density value of senescence-associated markers. Compared with the D-gal group, the contents of AST, ALT, TBiL, AGEs and MDA significantly decreased in the D-gal + Rg1 group, while the activities of SOD and GSH-Px markedly increased, and liver injury and degenerative alterations of hepatocytes were reduced. Administration of Rg1 induced a protective effect on D-gal-induced liver injury in mice by inhibiting the oxidative stress, reducing DNA damage and decreasing the AGE content.

Objectives. To demonstrate the effect of Ginsenoside Rg1 on the differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Subsequently, a rational mechanism for the detection of Rg1 which affects mesenchymal stem cell differentiation was explored. Methods. Flow cytometry is used for cell identification. The differentiation ability of hBM-MSCs was studied by differentiation culture. SA-β-gal staining is used to detect cell senescence levels. Western blot and immunofluorescence were used to determine protein expression levels. RT-qPCR is used to detect mRNA expression levels. Results. Rg1 regulates the differentiation of hBM-MSCs. Differentiation culture analysis showed that Rg1 promoted cells to osteogenesis and chondrogenesis. Western blot results showed that Rg1 regulated the overactivation of the β-catenin signaling pathway and significantly adjusted the phosphorylation of GSK-3β. GSK-3β inhibitor (Licl) significantly increased Rg1-induced phosphorylation of GSK-3β, which in turn reduced Rg1-induced differentiation of hBM-MSCs. Conclusion. Ginsenoside Rg1 can reduce the excessive activation of the Wnt pathway in senescent cells by inhibiting the phosphorylation of GSK-3β and regulate the mesenchymal stem cell differentiation ability.

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