Relationship of telomeres and p53 in aging bovine corneal endothelial cellcultures

PURPOSE. TO demonstrate a relationship between telomere lengths and levels of p53 in cultured bovine corneal endothelial cells (CECs) during aging. METHODS. Bovine CECs were grown and aged as long-term cultures. Telomere le ngths were determined directly on gels with P-32 probes after treatment of isolated DNA with RsaI and HinfI. Protein p53 was determined using an enzym e-linked immunosorbent sandwich assay. Cellular aging and the development o f replicative senescence were monitored by the appearance of senescent morp hology and the beta-galactosidase assay. RESULTS. Bovine CEC telomeres lost 4 kb (from 12.8 to 8.8 kb) over 1 year ( 89 population doublings [PDs]). The p53 levels in bovine CECs were initiall y small (similar to 60 pg/million cells), but rose 3.5-fold by culture age of 260 days (64 PDs). On initiation, cultured bovine CECs did not stain for the senescent marker beta-galactosidase. However, these cells stained at 8 9 PDs and senescent morphology was observed in the cultures at 64 PDs. CONCLUSIONS. The data indicate an inverse relationship between telomere len gths (decreasing and levels of p53 (increasing) in bovine CECs during aging . These properties may influence the ability of these cells to divide as th ey enter into replicative senescence.