The gene responsible for Werner syndrome may be a cell division "counting" gene.

AUTOR(ES)

Faragher, R G

RESUMO

Werner syndrome is a rare, autosomal, recessive condition that is frequently studied as a model of some aspects of human aging, although the behavioral changes that are usually associated with old age are only seen very infrequently. A most striking aspect of the phenotype of Werner syndrome, presumably arising from the same gene defect, is a dramatic shortening of the replicative life-span of dermal fibroblasts in vitro. The finite replicative life-span of human cells in vitro is due to the stochastic loss of replicative ability in a continuously increasing fraction of newborn cells at every generation. Normal human fibroblasts achieve approximately 60 population doublings in culture, while Werner syndrome cells usually only achieve approximately 20 population doublings. We describe an analysis of the replicative ability of fibroblasts from Werner syndrome patients and demonstrate that the cells in these cultures usually exit, apparently irreversibly, from the cell cycle at a faster rate than do normal cells, although they mostly start off with a good replicative ability. We propose that the Werner syndrome gene is a "counting" gene controlling the number of times that human cells are able to divide before terminal differentiation.

Documentos Relacionados

• Medical community may be partly responsible for cancer misery
• Bone marrow transplantation reproduces the tristetraprolin-deficiency syndrome in recombination activating gene-2 (-/-) mice. Evidence that monocyte/macrophage progenitors may be responsible for TNFalpha overproduction.
• Caseloads may be responsible for regional differences in care: CIHI report
• Evidence for a structural motif in toxins and interleukin-2 that may be responsible for binding to endothelial cells and initiating vascular leak syndrome
• Cis- and trans-acting elements responsible for the cell-specific expression of the human alpha 1-antitrypsin gene.