The Mannick-paper is really interesting - though it should be noted, that it's still paid for by Novartis.
To make sense of the pathway outlined in that study, I found this paper rather helpful:
"Protein Phosphorylation as a Key Mechanism of mTORC1/2 Signaling Pathways"
https://www.intechop...naling-pathways
If the numbers hold true, even small amounts of 0,5 mg of Rapamycin can inhibit mTORC1 activity by (up to) 38%. 5 mg up to 50%. Is this enough - particularly given that people for life extension take it once every 5-7 days?
Here I'm referencing the Kaeberlein paper:
"Rapamycin and aging: When, for how long, and how much?"
https://www.ncbi.nlm...les/PMC4401992/
and the 2009 lifespan study. To give a better picture of the required amount, let's look into the 2009 lifespan paper linked in my previous post. Quote:
"To document biochemical effects of rapamycin at the dose used for the lifespan studies, we evaluated the phosphorylation status of ribosomal protein subunit S6 (rpS6), a target substrate of S6 kinase 1 in the mTOR signalling pathway20, in visceral white adipose tissue (a sensitive indicator of mTOR inhibition by rapamycin treatment in vivo). Figure 3B shows that rapamycin reduced phosphorylated rpS6 4–5 fold when fed from 270 to about 800 days of age. Blood levels of rapamycin in the treated mice were equivalent in males and females, between 60 and 70 ng/ml."
There are 3 measures for rapamycin intake and effect in the paper:
1. food intake: 14 ppm concentration in food (2.24 mg/kg/day)
2. blood level: 60-70 ng/ml
3. phosphorylation: "reduced 4-5 fold"
Some illustrative numbers humans for comparison:
1. 2,24 mg/kg is - for a 70 kg person and allometric scaling - about 20-25 mg of Rapa per day. The best effects on longevity in mice in a later study even used the people-equivalent of about 70 mg of Rapa per day.
2. according to this study for effectiv blood level in transplant patients:
"Sirolimus: the evidence for clinical pharmacokinetic monitoring."
https://www.ncbi.nlm...pubmed/16029064
the desired level is 12-20 microg/liter (that is 12-20 ng/ml). Desired refers to minimizing side effects and still achieving immuno-supression; not maximising the immune effect.
3. Decrease "4-5 fold" is an imprecise expression. I'm assuming, that activity is reduced to 20%-25% of it's original activity - so 75%-80% reduction in mice. 5 mg according to Mannick can lead up to about 50% reduction.
By food-intake and blood-level, taking 5 mg every couple of days clearly is very far apart from anything used in mice to obtain life extension effects. Even in transplant patients blood levels are far short of levels seen in life extension mice. The phosphorylation numbers aren't quite as bleak. 50% remaining activity in man vs. 20% remaining in mice doesn't sound all too bad. If this is the main driver. But again - 5 mg aren't taken daily, so suppression to 50% is not 24/7 (the 20% in mice is).
I still wonder, that the mice didn't complain about side effects - ulcers/sores and rashes at all places - given that many humans tend to experience these at just 5 mg every 5-7 days. Let alone 25 mg every day. It might be, that mTOR is simply heavily upregulated in mice (i.e. fast development, many kids and die soon) compared to humans... so mTOR can be suppressed to a larger extend and not cause side effects. This of course could mean, that the life extension as seen in mice is not translatable, as humans have less mTOR activity as a baseline.
Given these numbers - especially if Rapa just corrects an overactive mTOR in mice (so humans are already good to go) - a 5 mg regime every monday of course likely falls (far?) short of the life extension benefits seen in mice. Taking it daily is not an option either.
Still undecided if it's reasonable to take it. But if everolimus got indeed less side effects I guess I give it the benefit of the doubt.
Damn.... just imagine that Rapa really just "corrects" overactivity in mice.... and in addition humans only obtain reduction to 50% for 1-2 days instead of 20% for 24/7... we really need those SENS-interventions.
Edited by Guest, 01 July 2019 - 12:15 PM.