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    Sirtuins, aging, and disease: longevity webinar

    22nd May 2008

    BiosymposiaFairly recently I did enjoy the webinar by Biosymposia. Dr. Leonard Guarente made a presentation first, and then there was a Q&A section.

    After taking WIPO‘s distant learning course in IP, I started paying more attention to distant learning techniques. In the long run, I assume that more and more structured knowledge (whole courses and learning programs) will be made available to the public for free.

    WIPO’s IP course was as a matter of fact a collection of textual and audio materials presented in a specific order, and interspersed with self-assessment questions to control learning progress, with a final exam at the end. Acknowledging the difference between the distant learning program and a webinar, Longevity webinar felt more like a tele-auditorium, with live-seeming (though actually pre-recorded) streaming presentation and video (side-by-side) by Dr. Leonard Guarente. It was just like attending a lecture :). The Q&A felt more like a TV show, in that listeners could write their questions during and a bit after the presentation, for the webinar hostess to ask Dr. Guarente those questions.

    Longevity is a question which bothers most of the people at some point in their lives. Amrita, the elixir of life, is one of the dominant topics of the Medieval Ages (alongside the any_metal-2-gold transformation idea).

    It has been known for quite a time that mice given less food than they would consume ad libitum, live noticeably longer than their free-eating comrades, and also preserve the signs of mouse youth until the latest days of theirs. In the longevity webinar, there was a video clearly showing the difference between ad libitum and calorie restricted mice on the 20th week of their life. It was quite impressive. One thing is to know, another is to see. Methuselah Foundation may have more information.

    The same caloric restriction effects were also observed for other animals. However, estimates for humans are not really attractive: 30% from normal caloric restriction in humans renders them nearly inoperable. That is, very low activity, no sex, and the quality of life is severely hampered.

    During the studies of the effects of caloric restriction, the sir2 gene gained some attention. It was found that this NAD-dependant deacetylase is activated during caloric restriction, and thus serves as and intermediary signal to the cell about the organism’s state. (some not exactly accurate statements here for the sake of brevity)

    Later on, sirtuins were found to be represented by a whole family of similar genes (just like alpha-interferons, but with less subtypes – around 7). Also, reservatrol was found to activate sirtuins. Reservatrol is one of wine polyphenols. (Note: answering questions, Dr. Guarente did not recommend taking reservatrol with hopes to prolong life, as there’s currently no model for the possible course of events, and especially for the life prolongation effect.)

    mTOR was also mentioned, but I didn’t remember the context.

    Another bit of information concerned sir2 levels. Dr. Guarente said that above certain level of sir2, further increase of level provides no improvement of longevity. Higher levels of sir2 exhibit toxic effects.

    The question was raised, whether providing both NAD producer (such as nampt) together with sir2 would give better effects. The answer is not yet known.

    There was also some connection mentioned between sirtuins and stress. My conclusion was “mild stress is good (unlike severe stress). Reason: mouse cortex development in stress/no-stress conditions clearly shows that no-stress mouse has a far less developed cortex, than the stress mouse”. Unfortunately, the connection of mild stress and longevity (or even sirtuins) is now evading me.

    Next webinar I’m likely to attend is Advances in G Protein-Coupled Receptor Research, this time from the Science magazine, scheduled for June, 17.

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