Phosphodiesterases 4D and 7A splice variants in the response of HUVEC cells to TNF-alpha

The mRNA accumulation of phosphodiesterases PDE4D and PDE7A was studied by RNA blot analysis in human umbilical vein endothelial cells (HUVEC) incubat ed with TNF alpha for different periods. A contrasting behaviour was observ ed in the mRNA accumulation of the two genes. Further analysis by RT-PCR of the PDE4D and PDE7A splice variants gave different accumulation patterns w hich may indicate that differential splicing has a role in the regulation o f these enzymes. Three previously undescribed PDE4D isoforms, with differen t accumulation patterns, were also detected. They code for truncated PDE4D isoforms, which could participate in the regulation of PDE4D activity. (C) 2000 Academic Press.