I seriously doubt that the cells are all of a sudden going to be able to take care of lipofuscin deposits. A lot of lipofuscins deposits exists because the cell does not have the mechanism to dissolve them;same goes from AGEs, ECM cross linking, and protein aggregations.
Its a debate on wear and tear, or..... LOL
Maybe he can explain it better
http://www.programme...ma_exchange.pdf
From what I have seen through a number of recent studies reversing aging using different methods, I would have to say it looks like wear and tear has had its day. When build and repair fails/ends, then it just appears wear and tear has happened and is the cause. Just a guess on my part and some others.
I think you'll have a hard sell with this one. The proponents of programmed aging point out that some degree of rejuvenation occurs when you put an old cell into a young environment, but I don't think they are addressing a couple things. The first is how does the young environment get "old"? Is it caused by damage? The second relates to the cells they are looking at. If the mitochondria are shot, the telomeres are gone, or the lysosomes are bloated, then all the youth signals in the world aren't going to help that cell. How does programmed aging explain that?
Remember the young rapidly age when exposed to old blood, which is the reverse condition. How a cell acts seems to be guided in part by the shortening or lengthening of the telomeres, and the genetics change, so does the way the cell behaves changes and looks. Old cells with relengthen telomeres of humans cells start acting or functioning like they are young again and look under the microscope almost like a newborns, instead of the cells of an 80 year old. I suspect when the young signals come out this happens to the cells. I also suspect that our bodies are damaged by the bad cells with the short telomeres spewing the poisons (senescent cells), and when they stop they are repaired or replaced as needed if too badly damaged.
In other words you have several different processes going on at the same time, to change the way the cells act and look, and another process of tear down and replacement of too badly damaged cells. Now, no one has spoken about, or perhaps looked at yet what is going on with the telomere length in the younger environment, but I suspect it is changing to a longer version and that will change how those cells look and behave. They mainly focus on the stem cells being produced and going to different areas of the body for repair, which is great but I don't think it explains fully what they are seeing rapidly in the old mice, in days or a in few weeks. The enlarged heart shrinks back and they are able to run again almost with the speed and stamina of the young, and all the rest they are seeing in a fairly short period. I don't think this is simple repair by the new stem cells now being produced, but reminds me of another age reversals, also at Harvard, using a simple 30 day boost of telomerase in them.
The cells in us seem to go through an almost constant two step process of destroying cells and then replacing them throughout our lifetime. But what happens on the spine for example if the destruction process continues and the repair and replacement part falls behind or stops?? It is known, with smokers for example, the repair replacement is hindered by smoking. Ageing itself may be little more then about that balance failing further down the road but more slowly.
In October the first human trials will start in Australia and more research and answers should be out though I am not real crazy about how they set it up giving them only some younger blood one time, and then asking for observations of a change. This, to my understanding, is not how any of the mice trials were done either with young blood, or GDF11 alone. It almost sounds like it is set up to fail.
In the end, if with have age reversal then the signs of damage can not and will not exist anymore because of the change by telomere, or by the tear down replacement cycle normal in the body, which is a longer process that takes sometimes decades one cell at a time. By the day or month, we learn what we did not about the whole subject, and find out a lot more yes we cans, then no we can not.
Just my view, as always, and reduced or condensed way down because of the slowness of my typing LOL