[Effects of hypoxic preconditioning on glucose metabolism of rat bone marrow mesenchymal stem cells].

OBJECTIVE

To study the effects of hypoxic preconditioning on the glucose metabolism of rat BMSCs and its underlying mechanism so as to provide the theoretical basis for the optimization of the stem-cell based therapy.

METHODS

Density gradient centrifugation method was adopted to isolate rat BMSCs from neonatal SD rats (aged 1-3 days). BMSCs were cultured to 4th passage and divided into 4 groups based on different culture conditions: group A in normoxia condition for 24 hours, group B in 1% O2 for 24 hours, group C in 2-methoxyestradiol (20 micromol/L) for 24 hours before hypoxic preconditioning, and group D in hypoxia-inducible factor 1 (HIF-1) specific siRNA (50 micromol/L) for 12 hours before hypoxic preconditioning. MTT method was applied to evaluate the proliferation of BMSCs. Biochemical analyzer and Real-time fluorescent quantitative PCR were applied to detect the glucose uptake, lactate production, and HIF-1alpha mRNA and Glut-1 mRNA levels of BMSCs.

RESULTS

MTT showed that the absorbance (A) values were 387.67 +/- 58.92, 322.50 +/- 50.60, 297.00 +/- 53.00, and 286.00 +/- 41.00 in groups A, B, C, and D, respectively, showing no significant difference among 4 groups (P > 0.05). The levels of glucose uptake and lactate production were higher in group B than in groups A, C, and D, showing significant differences (P < 0.05); the levels of groups C and D were higher than those of group A, but showing no significant difference (P > 0.05). The mRNA expressions of HIF-1alpha and Glut-1 elevated significantly in group B when compared with those in group A (P < 0.05); groups C and D were significantly lower than group B (P < 0.05) and were significantly higher than group A (P < 0.05).

CONCLUSION

Hypoxic preconditioning can stimulate the glucose uptake and metabolism of rat BMSCs, whose mechanism is probably related to up-regulating the mRNA expressions of HIF-1alpha and Glut-1.