Werner's Syndrome, Progeria and Cellular Senescence
Chris Patil looks at recent attempts to find common mechanisms in accelerated aging disorders: "some conditions are best thought of 'segmental' progerias (in that they model aging only in specific organs or cell types), whereas others model the natural aging process very closely in the majority of tissues. Chief among the latter are Werner's Syndrome (WS) and Hutchinson-Gilford Progeria Syndrome (HGPS). The underlying mutation in the two diseases are quite different: WS is due to a mutation in a DNA helicase involved in repair, whereas HGPS is caused by a dominant mutation in lamin A/C, which is critical to nuclear structure (and consequently in gene regulation). While the diseases have distinct phenotypes and ages of onset, they are both widely considered good models of accelerated aging. What, if anything, is the common currency between the two? ... Cox and Faragher argue that premature cellular senescence is likely to be important in both WS and HGPS ... According to this model, senescence (which permanently growth-arrests old and damaged cells) prevents individual cells from forming tumors, but persistent senescent cells embark on a highly anti-social program of gene expression that can [damage] surrounding tissues and may contribute to age-related decline in tissue function."
Link: http://ouroboros.wordpress.com/2007/08/10/cellular-senescence-in-progeroid-syndromes/