For the First Time, Organ Regenerated Inside a Living Animal 94
ananyo (2519492) writes "Scientists at Edinburgh University have successfully persuaded an organ to regenerate inside an animal. As they report in the journal Development, they have treated, in mice, an organ called the thymus, which is a part of the immune system that runs down in old age. Instead of adding stem cells they have stimulated their animals' thymuses to make more of a protein called FOXN1. This is a transcription factor (a molecular switch that activates genes). The scientists knew from earlier experiments that FOXN1 is important for the embryonic development of the thymus, and speculated that it might also rejuvenate the organ in older animals. They bred a special strain of mice whose FOXN1 production could be stimulated specifically in the thymus by tamoxifen, a drug more familiar as a treatment for breast cancer. In one-year-olds, stimulating FOXN1 production in the thymus caused it to become 2.7 times bigger within a month. In two-year-olds the increase was 2.6 times. Moreover, when the researchers studied the enlarged thymuses microscopically, and compared them with those from untreated control animals of the same ages, they found that the organs' internal structures had reverted to their youthful nature."
Can't argue with function, though. (Score:4, Interesting)
Don't care. If the organ is restored to youthful function, as at least the linked summary indicates, then this is a big deal.
Specifically, this appears to be very different from (say) cardiac hypertrophy, where the heart grows larger but works less efficiently. In this work, the "rejuvenated" thymus not only gets bigger, it produces more T cells -- in other words, it works more like a youthful organ.
Re:And the telomeres? (Score:5, Interesting)
Presumably the telomeres continue to diminish as normal; however, unless I'm much mistaken organisms rarely survive long enough for their cells DNA to run out of telemorase. Instead the problem is a far more complicated and poorly understood - some of aging happens at the cellular level, but far more happens at a system level, and we don't really understand the interaction. It sounds like they may have found a way to rejuvenate an organ at the system level, presumably at a some increase in aging at the cellular level (a 3x increase in size could well be responsible for less than 1.6 generations of cellular aging), but if we could extend lifespans such that it was generally cellular aging that killed us rather than systemic aging, that would be a pretty impressive leap forward. As a side benefit greater systemic health probably promotes greater cellular health, so we might end up with cells more like that spry centenarian happily working his farm rather than the decrepit 70yo who's doing good to wipe his own ass.
Re:Alright, alright,alright (Score:4, Interesting)
And so perhaps we should pay more attention to the old Conservative viewpoint that both unrestrained capitalism and socialism are detrimental to the human soul, and that a society should strive to enable all it's citizens to acquire sufficient real estate and other capital to support their family without having to subject themselves to servitude to others or depend on government largess.