[Inhibitory effect of total saponins of Panax notoginseng on rat bone marrow mesenchymal stem cell apoptosis].

The study was aimed to investigate the effects of total saponins of Panax notoginseng (tPNS) on cobalt chloride (CoCl2)-induced apoptosis of rat bone marrow mesenchymal stem cells (rBMSCs) and the underlying mechanism. rBMSCs were isolated by density gradient centrifugation from Sprague Dawley (SD) rats. After being incubated with different concentrations of tPNS (1, 10, 100 µg/mL) for 48 h, the rBMSCs were stained with EdU and PI for proliferation and cell cycle assay, respectively. CoCl2 group was treated with 300 µmol CoCl2 for 24 h, and different concentrations tPNS groups were treated with 300 µmol CoCl2 plus 1, 10 or 100 µg/mL tPNS. After Annexin V-FITC/PI staining, flow cytometry was applied to measure the cell apoptosis. For mitochondrial membrane potential assay, rhodamine123 and Hoechst33342 staining were used. qRT-PCR was applied to analyze gene expression of Bcl-2 family. The results showed that the proliferation rates of the three concentrations tPNS groups were all higher than that of the control group (all P < 0.05). Compared with control group, only 100 µg/mL tPNS group exhibited increased cell percentage of S and G2 phase. Compared with that in control group (without CoCl2), the apoptotic rate was increased by 14.2% in CoCl2 group. And the apoptotic rates were reduced by 14.4%, 12.8% and 13.9% in three concentrations tPNS groups, compared with that in CoCl2 group (all P < 0.01). CoCl2 could decrease the mitochondrial membrane potential, while different concentrations of tPNS reversed the inhibitory effect of CoCl2. Bcl-2 and Bcl-xl mRNA expressions in all tPNS groups were higher than those in CoCl2 group (all P < 0.05). Moreover, 10 and 100 µg/mL tPNS groups showed lower ratios of Bax/Bcl-2, compared with CoCl2 group. The results suggest that tPNS protects the rBMSCs against CoCl2-induced apoptosis through improving the cell mitochondrial membrane potential, up-regulating the expressions of anti-apoptosis genes Bcl-2 and Bcl-xl, and reducing the Bax/Bcl-2 gene expression ratio.

Ginsenoside Rg1 protects rat bone marrow mesenchymal stem cells against ischemia induced apoptosis through miR-494-3p and ROCK-1.

This study aimed to verify the cytoprotective effect of ginsenoside Rg1 in vivo, and to elucidate the mechanism of Rg1 in the ischemic microenvironment. Male rat bone marrow mesenchymal stem cells (rBMSCs) or rBMSCs treated with Rg1 were injected into ischemic region of the arterial embolism hind limb in female rats. Behavioral and histological data, obtained one-week post injection, showed that rBMSCs with Rg1 could improve the survival rate of BMSCs and enhance the therapeutic effects. rBMSCs treated with hypoxia and serum deprivation for 24h (H/SD-rBMSCs) showed the up-regulated expression of ras homolog family member A (RhoA), Rho associated coiled-coil containing protein kinase 1 (ROCK-1), myosin light chain 2 (MLC-2), Bcl2 associated agonist of cell death (Bad) and Bcl2 associated X, apoptosis regulator (Bax); while the expression of miR-148b-3p, miR-148b-5p and miR-494-3p was down-regulated. H/SD with Rg1 treatment (H/SD+Rg1-rBMSCs) inhibited the expression of ROCK-1, MLC-2, Bad and Bax, increased the expression of Bcl-2, miR-494-3p. After ROCK-1 knockout, the expression of Bad and Bax were downregulated and Bcl-2 upregulated, but Rg1 no longer altered their expression. Mir-494-3p functional study established that miR-494-3 mimic downregulated and miR-494-3 inhibitor upregulated ROCK-1 gene expression, Rg1 did not have the ability to change the ROCK gene expression after loss of function of miR-494-3p. Also, the function loss of mir-494-3p promoted apoptosis; otherwise reduced apoptosis. The anti-apoptotic effect of Rg1 disappeared after mir-494-3p loss or gain function. In conclusion, Ginsenoside Rg1 has shown to have protective effects on ischemic-induced rBMSCs apoptosis through mir-494-3p→ROCK-1→Bcl-2 signaling pathway.