Cellular aging is accompanied by alterations in gene expression patterns. Here, 
using two models of replicative senescence, we describe the influence of the 
RNA-binding protein HuR in regulating the expression of several genes whose 
expression decreases during senescence. We demonstrate that HuR levels, HuR 
binding to target mRNAs encoding proliferative genes, and the half-lives of such 
mRNAs are lower in senescent cells. Importantly, overexpression of HuR in 
senescent cells restored a "younger" phenotype, while a reduction in HuR 
expression accentuated the senescent phenotype. Our studies highlight a critical 
role for HuR during the process of replicative senescence.