Figure 5a-c. Bcl-xL, decreases senescence, enhances proliferation and protects against oxidative damage in mouse embryo fibroblasts (MEFs) in primary culture. (a) Bcl-xLover-expression in MEFs. (b) Bcl-xLdown-regulates expression of age-associated cell cycle inhibitors: RT-PCR mRNA expression analysis of p16Ink4a, p19Arf, and p21CIP in MEFs retrovirally transduced withBcl-xLorpMIG (controls) (n=7 in each group). (c) Bcl-xL over-expression increase proliferation in MEFs (determined as P-H3 positive cells)