OBJECTIVE: To investigate the relation between the effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence and the expression of p16(INK4a). The purpose is to provide the theory and experimental foundation for searching the methods of how to delay HSC senescence.
METHOD: Sca-1 + HSC was isolated by magnetic cell sorting (MACS) and divided into five groups. The control group cells were routinely cultured, the aging group cells were induced aging by tert-butylhydroperoxide( t-BHP, final concentration of 100 micromol x L(-1)) to establish the aging model, the Rg1 group cells were co-cutured with Rg1 (final concentration is 10 micromol x L(-1)). To Rg1 delay aging group, Sca-1 + HSC were established aging model after pretreatment of Rg1 (final concentration is 10 micromol x L(-1)). To Rg1 treat aging group, Sca-1 + HSC gave Rg1 (final concentration is 10 micromol x L(-1)) antiaging treatment after the aging model was established. The changes of cells observed by senescence-associated beta-galactosidase (SA-beta-gal) staining, cell cycle analysis and culture of mixed hematopoietic progenitor cell were used to investigate the antiaging and delay aging effect of ginsenoside Rg1. The expression of senescence associated p16(INK4a) mRNA and p16(INK4a) protein was examined by RT-PCR and western blotting.
RESULT: Compared with aging group, the percentage of positive cells expressed SA-beta-gal and cells in G1 phase decreased and the number of forming colony of mixed hematopoietic progenitor increased and it showed higher expression of p16(INK4a) mRNA and p16(INK4a) protein in Rg1 treat aging group and Rg1 delay aging group. Furthermore the percentage of positive cells expressed SA-beta-gal, cells in G1 phase, the number of forming colony of mixed hematopoietic progenitor and the expression of p16(INK4a) mRNA and protein decreased in Rg1 delay aging group compared with Rg1 treat aging group.
CONCLUSION: Rg1 can significantly delay and treat the senescence of Sca-1 + HSC. The effect of Rg1 delaying aging is better than treatment, p16(INK4a) may be play a key role in the antiaging effect of Rg1 to Sca-1 + HSC senescence induced by t-BHP.
