Cellular ageing in fibroblast cultures from elderly aged 90 years old Diana van Heemst, Dept. Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
Link between cellular ageing in vitro and chronological ageing in vivo ? Inconsistent results: -Inverse relationship: replicative lifespan - donors age (Martin 1970, Schneider 1976,Smith 1978, Goldstein 1978, Allsopp 1992) -No correlation (Cristofalo 1998) -High inter-individual variation Aim: Variability in growth kinetics in fibroblasts from elderly aged 90 years? Background
Leiden 85-plus Study – prospective population based study, inhabitants of Leiden, The Netherlands - birth cohort , follow-up 5 years - age of 90 years (n=68): - good physical and mental health - fibroblast cultures started from 3 mm skin biopsies - standardised procedures Study design
Fibroblast growth kinetics in mass cultures I IIa IIb III Hayflick 1961 I IIa IIb III PD days Phase I –initiation of the culture Phase IIa –steady proliferation Phase IIb –decrease in proliferation Phase III –growth arrest
Growth kinetics (n=68) Culture: days
no strain failed to proliferate all easily cultured all typical growth phases –initiation –proliferation –senescence (n=10) reproducibility CV (sd): (+/- 9.5) % (n=33) huge variability in growth kinetics Results
Modeling growth kinetics (n=10) Phase 1, 2a, 2b: no differences in speed of growth (0.304 (+/ ) PD/day in 2a and (+/ ) PD/day in 2b) Transition 2a/2b: striking differences: PD, days
Modeling growth kinetics (two examples) Transition 2a/2b S324: 47 PD (147 days) S182: 67 PD (229 days)
Transition phase 2b/3 (n=10) Phase 3: not subcultured 75 days without increase in cell density ( days) Transition 2b/3: striking differences: PD, days
High intra-biopsy reproducibility Very high proliferative capacity left – mixture of clones, cell clone with the highest proliferative capacity responsible for replicative capacity High variation in growth kinetics in fibroblasts from elderly in transitions 2a/2b and 2b/3 Future prospects: mechanism transition points (ß-galactosidase), relation with subject characteristics (health, remaining life span) Conclusions
Andrea Maier Corine de Koning-Treurniet Joke Blom Ton de Craen Simon Mooijaart Rudi Westendorp Acknowledgements