%0 Journal Article
%T Gamma-tocotrienol modulation of senescence-associated gene expression prevents cellular aging in human diploid fibroblasts
%A Makpol
%A Suzana
%A Zainuddin
%A Azalina
%A Chua
%A Kien Hui
%A Yusof
%A Yasmin Anum Mohd
%A Ngah
%A Wan Zurinah Wan
%J Clinics
%D 2012
%I Faculdade de Medicina / USP
%R 10.6061/clinics/2012(02)08
%X objective: human diploid fibroblasts undergo a limited number of cellular divisions in culture and progressively reach a state of irreversible growth arrest, a process termed cellular aging. the beneficial effects of vitamin e in aging have been established, but studies to determine the mechanisms of these effects are ongoing. this study determined the molecular mechanism of ¦Ã-tocotrienol, a vitamin e homolog, in the prevention of cellular aging in human diploid fibroblasts using the expression of senescence-associated genes. methods: primary cultures of young, pre-senescent, and senescent fibroblast cells were incubated with ¦Ã-tocotrienol for 24 h. the expression levels of eln, col1a1, mmp1, ccnd1, rb1, and il6 genes were determined using the quantitative real-time polymerase chain reaction. cell cycle profiles were determined using a facscalibur flow cytometer. results: the cell cycle was arrested in the g0/g1 phase, and the percentage of cells in s phase decreased with senescence. ccnd1, rb1, mmp1, and il6 were upregulated in senescent fibroblasts. a similar upregulation was not observed in young cells. incubation with ¦Ã-tocotrienol decreased ccnd1 and rb1 expression in senescent fibroblasts, decreased cell populations in the g0/g1 phase and increased cell populations in the g2/m phase. ¦Ã-tocotrienol treatment also upregulated eln and col1a1 and downregulated mmp1 and il6 expression in young and senescent fibroblasts. conclusion: ¦Ã-tocotrienol prevented cellular aging in human diploid fibroblasts, which was indicated by the modulation of the cell cycle profile and senescence-associated gene expression.
%K vitamin e
%K molecular mechanism
%K cellular aging
%K senescence-associated genes
%K human diploid fibroblasts.
%U http://www.scielo.br/scielo.php?script=sci_abstract&pid=S1807-59322012000200008&lng=en&nrm=iso&tlng=en