Effects of glucose restriction on replicative senescence of human diploid fibroblasts IMR-90.

BACKGROUND/AIMS The aim of this study was to elucidate the effects of glucose restriction (GR) on cell replicative senescence in vitro by human diploid fibroblasts IMR-90. METHODS IMR-90 cells were cultured under 40, 60% GR or high glucose medium and biomarkers of cell senescence were compared with cells cultured in normal glucose medium (5.5 mM glucose). The impact of different concentrations of glucose and initial passages on cell replicative senescence were assessed by cell survival days, cumulative population doublings (PD), cell proliferation rate (CPR) and SA-β-gal site-stain. RESULTS When compared with control cells, mean survival days and lifespan of IMR-90 were increased 16.7% and 11.4% by 40% GR (3.3 mM glucose). However, mean survival days and lifespan of IMR-90 were decreased 31.0% and 26.9% by HG treatment (25.0 mM glucose). The effects on survival days of IMR-90 were associated not only with different glucose concentrations but also with initial passages. The CPR of IMR-90 could be retarded by GR culture and this effect was especially associated with GR degree. It was 87% positive cells of SA-β-gal in aging stages and more slim and fibrous cells were observed in 40% GR group than NG group onset from 26 PD. CONCLUSION Mean survival days and lifespan of human diploid fibroblasts IMR-90 were extended by glucose restriction. The higher GR levels, the earlier onset of GR, the larger benefits on extending survival days of IMR-90 could be observed. Slowing down cell proliferation by GR increased the number of cell survival days, an effect associated with GR levels. High glucose induced premature senescence of IMR-90 when started from any passages.