Analysis of Werner's expression within the brain and primary neuronal culture.

Werner's syndrome is a genetic progeria disorder caused by mutation of the Werner gene (WRN). The presence of mutations in the WRN gene is believed to result in a deleterious loss of normal WRN function, which has been best characterized for its role as a DNA helicase and exonuclease. The WRN gene is known to be expressed within the central nervous system, with Werner's syndrome associated with several neuropathological abnormalities including brain atrophy, gliosis and extensive cytoskeletal abnormalities. While WRN has been intensely investigated in primary fibroblast and fibroblast cell lines, at present little is known about the normal expression pattern of the WRN protein in the brain or primary neuronal cultures. In the present study we demonstrate that WRN is expressed throughout the brain, and is present in both neurons and glia. Similarly, WRN is present in both primary neurons and glia in cell culture, with extensive immunoreactivity present in the neuritic processes or neurons. Analysis of WRN RNA revealed that WRN was expressed at its highest levels in brain tissue from embryonic tissue, undergoing a biphasic pattern expression from early post-natal period into adulthood. Taken together, these data indicate that WRN is present in the cells of the brain, expressed throughout primary neuronal cells in culture, possibly playing a developmental role in the central nervous system.