itchcrotch said:
am i extremely interested in this!
tell me more! don't be a afraid to get detailed, i have a limited but not non-existant understanding of biology and cell science. i want to know more!
my uncle was telling me a little while ago about some scientists who managed to swich of a production of a certain chemical or cell function (i can't remember) and the mice's organs began rapidly degrading, then as soon as they switched it back on, the organs became healthy again, as if they had controlled the rate of aging.
Love a person who wants to get educated. Ill summarise my paper for you.
Senescence is the shortening of telomere length in DNA with every reproduction of a cell. The value called Hayflicks limit is the amount of times a cell can divide before the telomeres get too short and it cant divide anymore. Stem cells have no limit, but the second they differenciate into specific cells they are affected by this process. Rats have 15 divides. Gallapagos tortoises get 115. After this cells start to die without replacing themselves properly in what we call apoptosis, or cell suicide. They kill themselves in an orderly way, gathering everything together into a package to be taken and broken down for parts, rather than die chaotically because the enzymes in them would damage other cells.
Anyway when you reach hayflicks limits (some cells get there before others) tissues start to weaken and become damaged, thus why organ failure is so common in the very old. Reaching hayflicks limit was impossible before because we died so early, now we actually achieve our biological clock age. Dolly the sheep died early btw because she was cloned from a cell that was already halfway through hayflicks limit, thus she was born with all cells having shorter telomere length. That meant she effectively was born with a biological age of 5. Weird stuff.
Ages ago we developed this to fight cancer. When the telomere shortening gene stops, the one that actively makes cells age, a tumor starts, as cells now have no hayflicks limit or dividing regulation they become "immortal". Yep cancer is immortal as long as it is fed. Cool story, there is over 10 metric tonnes of a woman who had the most aggressive tumor ever that is used all over globe as testing tissue, simply because her tumor divided so fast it was easy to use. And immortal as long as it was fed. Fun stuff.
Some animals are immortal, a jellyfish called turritopsis nutricula can turn all its cells into stem cells, refreshing telomere length and starting the process again as an embreo. Its very cool stuff and a lot of my paper is on this jellyfish. Jellyfish though are very simplistic organisms, so cancer isnt an issue for them, especially seeing as they can do this before they even get close to hayflicks limit for them. They are however slow tastey and stupid so population isnt really an issue for them.
http://en.wikipedia.org/wiki/Telomerase
Telomerase. Causer of cancer and the enzyme that can repair telomeres back to full, thus reversing aging. If we can beat cancer, we can enable this enzyme and not get a tumor. We could use it to live forever. Stem cells are caked in it, which means they dont age, so is your immune system. Your heart muscles and brain? Not so much.
Tests on mice show it makes them live longer biologically but causes cancer. Thus our problem today. Your uncle was talking about these tests. The mice do show a reaction to the enzyme.
Interesting stuff? I hope you think so. Glad to help, ask any questions you may have.
