Effects of PTEN on the longevity of cultured human umbilical vein endothelial cells: the role of antioxidants.

Abstract

Ageing is a major cause of illness, disease and mortality, mainly due to the shortening of telomeres, resulting in cells undergoing senescence and apoptosis. Increasing autophagy and the levels of antioxidants removes oxidants that cause DNA and telomere damage, thus reducing the rate at which telomeres shorten, resulting in a longer cellular lifespan. Phosphatase and tensin homolog (PTEN) has been shown to increase the lifespan of organisms by upregulating pathways involved in DNA damage repair, autophagy/antioxidants. The aim of this study was to investigate the effects of the overexpression of PTEN on the longevity of human cell cultures by examining the increase in antioxidant potential. Human umbilical vein endothelial cell (HUVEC) cultures were transfected with PTEN plasmids using lipofectamine. An assay was performed to quantify the protein levels of PTEN and the antioxidant potential of the cell cultures. The cell cultures were maintained until senescence occurred in order to determine longevity. The results of each assay were then compared and correlated with each other and with the longevity of the cells. The transfected cultures showed a significant increase in PTEN protein levels, total antioxidant potential and longevity (all P-values <0.001) compared with the non-transfected cell cultures. The correlation coefficient between cell longevity and PTEN levels was 0.8727; and the correlation coefficient between cell longevity and antioxidant potential was 0.6564. The successful transfection of PTEN led to an increase in PTEN levels, antioxidant potential and an increased cellular longevity. This study demonstrates that there is a potential for PTEN to be used to extend human longevity. This can lay the foundation for further studies to be carried out on humans involving PTEN and longevity.