Hur Protein And Thy-1 Mrna Decay In Mouse S49 Lymphosarcoma Cells

Stress is associated with immune dysfunction. Our laboratory has shown that the neurotransmitter norepinephrine (NE) increases the rate of Thy‐1 mRNA decay in S49 T lymphoma cells through a classical β 2 AR/AC/cAMP/PKA pathway, identified an ARE (a sequence associated with message regulation) in the 3’UTR of Thy‐1 mRNA and at least 10 ARE binding proteins for the Thy‐1 mRNA ARE including AUF1, HuR, TIAR, KSRP, and Hsc70. This study investigates the relationship between HuR expression and cAMP mediated Thy‐1 decay by knocking down HuR with short hairpin RNA (shRNA). S49 cells were stably transfected with a vector containing either a nonspecific scrambled shRNA (scr) or an shRNA specific for HuR. Whole cellular HuR protein levels detected by immunoblotting and mRNA levels detected by qPCR showed a 50% decrease in the expression of HuR in the knockdown cells compared to the scr cells. This decrease of HuR expression in the HuR shRNA cells did not alter the basal levels of Thy‐1 mRNA, but did correlate with an increase in Thy‐1 message decay after 4 hrs of treatment with a cAMP analogue. These results suggest a stabilizing role for HuR in cAMP mediated Thy‐1 mRNA decay. Supported by NIH.