A feature article in SCIENCE this week (1) summarized some very impressive work from Amy Wagers (Harvard) and other researchers on blood factors that seem able to partially reverse age-related tissue degeneration. Several groups have used a technique termed parabiosis to establish a shared circulation between old and young mice. This resulted in improved function in muscles, heart, and nerves of the older mice. One possibility is that blood factors from young mice restore the ability of stem cells in older animals to repopulate damaged tissues. In an exciting new development Wagers and colleagues have identified a protein termed GDF11 as the rejuvenating blood factor. GDF11 is a member of the TGB-beta family of growth factors that regulate many aspects of tissue differentiation and growth.
These results would seem to open up new opportunities for clinical approaches that address ageing per se rather than individual diseases associated with ageing. Some strong arguments have been made that this approach would make a much greater contribution to human health and longevity than disease specific therapies (2).
(2) Goldman, D. P., et al. (2013), 'Substantial health and economic returns from delayed aging may warrant a new focus for medical research', Health Aff (Millwood), 32 (10), 1698-705.