1079 replies to this topic

[Turnbuckle]

Thanks, Turnbuckle. I didn't include the timeline of the cut, it was around 5 days after Fisetin - I seem to recall it has a short half life. If it isn't well known I'll see if I can dig around and find the reference to senolytics and healing. 

 

Then it shouldn't have been a problem.

[ambivalent]

'Senescent cells, however, are not all bad, and evidence shows that they play a role in cellular reprogramming [16] and wound healing. Like all things in biology, it is therefore clearly a question of balance: too much clearance of senescent cells would be bad for wound healing and cellular reprogramming, but too many senescent cells lead to damage'

 

https://www.leafscie...org/senolytics/

[Turnbuckle]

'Senescent cells, however, are not all bad, and evidence shows that they play a role in cellular reprogramming [16] and wound healing. Like all things in biology, it is therefore clearly a question of balance: too much clearance of senescent cells would be bad for wound healing and cellular reprogramming, but too many senescent cells lead to damage'

 

https://www.leafscie...org/senolytics/

 

If you go to the reference for this statement, you find this--

 

INTRODUCTION: The ectopic expression of

transcription factors OCT4, SOX2, KLF4,

and cMYC (OSKM) enables reprogramming

of adult differentiated cells into pluripotent

cells, known as induced pluripotent stem cells

(iPSCs), that are functionally equivalent to embryonic

stem cells. Expression of OSKM in vivo

leads to widespread cell dedifferentiation and

reprogramming within tissues and eventually

to the formation of teratomas (tumors arising

from iPSCs). 

 

CONCLUSION: The expression of OSKM

in vivo triggers two different cellular outcomes:

reprogramming in a small fraction of cells, and

damage and senescence in many other cells...

 

https://sci-hub.se/1...science.aaf4445

 

 

[OP2040]

Is it reasonable to speculate that lab mice would have less senescent cell burden than humans because they are in a protected environment, and because they have naturally longer telomeres?  If we assume this, then it would seem reasonable to say that humans should benefit much more from senolytics than mice (ceteris paribus).  I can't find any studies that directly compare senescent cell burden or SASP between mice and humans. 

 

A further assumption we could make is that cellular reprogramming will be needed to see actual age reversal or disease amelioration in humans.  Senolytics could be expected to slow down aging or disease a great deal.  But the main reason we can cure all kinds of diseases in mice is that they have longer telomeres, so once a damage is removed, their cells are able to support a new, healthier homeostasis.  Humans don't have the same ability, though we are much more protected from cancer.

[ambivalent]

ok, I had time to read through the initial article. A great example of the engineering problem aging poses, the favouring of selection for making the best of a bad situation - how to carefully wean the body of its dependency on senescent cells (or perhaps carefully calibrate).

 

So my take is we shouldn't be too worried about the cellular reprogramming-hit of senescent cell clearance because it isn't sufficiently significant and only becomes important when the levels of senescent cells are very high - an aging signal which we hopefully counter with senescent cell clearance and mitigate the need for reprogramming (sounds a little hopey).

 

I have concerns and queries regarding delayed healing. How is this process changing with age? Is healing mediated by senescent cells the mechanism (partly) through which a child heals (with presumably a much lower but still requisite store of senescent cells)? It would/will be interesting to know how long this healing deficit lasts. My very subjective experience witnessed a small constant flow rate of a very tiny wound consistently for several hours then completely stop, which does tie in with the presence of a signalling threshold - it hadn't been noticed for hours, then it was trivially solved (which is a clear concern). So will there be a homeostatic response to compensate for too many lost senescent cells?

 

Another observation I didn't mention was fatigue: my sleeping patterns are too inconsistent to reliably measure, but I have felt unusually tired (and looked subjectively paler). I would also ramp up the significance of the post-sleep neck strain, it actually worsened yesterday late in the day and has undoubtedly persisted far longer than on any occasion I can remember in recent years.  

 

A recent passing anecdote re-surfaced after watching the short talk in the previous link. The speaker mentioned post senolytic hair regrowth in mice, a friend of my uncle's who had recently suffered cancer experienced head hair regrowth (presumably post-chemo). I don't know if this is commonly reported and (currently) can't be any more specific than this.

 

 

 

 

 

  

Edited by ambivalent, 02 November 2018 - 05:23 PM.

[QuestforLife]

Is it reasonable to speculate that lab mice would have less senescent cell burden than humans because they are in a protected environment, and because they have naturally longer telomeres? If we assume this, then it would seem reasonable to say that humans should benefit much more from senolytics than mice (ceteris paribus).

Nope. Quite simply because the main cause of cellular senescence is ROS, and mice cells have much higher ROS than humans'. So I'd expect mice to accumulate senescent cells much more quickly.

Can't find the study right now, but senescent cells have been found to correlate well with age in mice, but not with humans - simply because detection is not good enough (for smaller numbers I speculate).

Mice will always have regnerative potential (once excessive SASP is resolved) because of long Telomeres, as you mention, so senescent cell removal is a win-win if you're a mouse.

We've yet to find out if humans can benefit in the same way. We don't have such long Telomeres to replace those cells lost to senolytics, but then we probably have less senescent cells as a percentage of total cells.

Edited by QuestforLife, 02 November 2018 - 06:18 PM.

[xEva]

sorry for the offtop but this notion that "mice have long telomeres, therefore..." is not entirely true, meaning that they do have them longer than humans, at birth, but years ago Blasco (-?) showed that their telomere attrition rate is 100 times higher. This means that they should start running out in about 2.5-3 years, which corresponds to their lifespan.

 

But when something is repeated often enough is sorta becomes true -- and so I for one began to doubt and getting confused about the whole thing.  Has anyone seen a study where it was shown that indeed mice have their telomeres long in their old age? I think it's important to resolve, coz lotsa conclusions are based on this popular assumption, but what if it's wrong?

Edited by xEva, 02 November 2018 - 06:41 PM.

[OP2040]

I like to see studies on these things, even though I know it's a pain to look them up.  Whichever way it can be spun, cellular reprogramming will be needed before true rejuvenation is seen.  Senolytics are probably great for healthspan, which is a good enough reason to use them.  But I'm hoping now that we are actually quite far along in terms of senolytics, people will shift their enthusiasm to cellular reprogramming.  . 

 

 

[OP2040]

sorry for the offtop but this notion that "mice have long telomeres, therefore..." is not entirely true, meaning that they do have them longer than humans, at birth, but years ago Blasco (-?) showed that their telomere attrition rate is 100 times higher. This means that they should start running out in about 2.5-3 years, which corresponds to their lifespan.

 

But when something is repeated often enough is sorta becomes true -- and so I for one began to doubt and getting confused about the whole thing.  Has anyone seen a study where it was shown that indeed mice have their telomeres long in their old age? I think it's important to resolve, coz lotsa conclusions are based on this popular assumption, but what if it's wrong?

 

You are absolutely right Eva.  It was just laziness on my part in order to get the larger point across.  They have longer telomeres at birth but sustain much more damage than humans.  The other factor that often gets confused here is whether telomerase remains active or not.  If I am recalling correctly, some N.S. animals have telomerase active for their entire lives, whereas mice and humans don't.  It really is all about telomere mechanics, as it is a process.  But ya, intellectual laziness.....

[QuestforLife]

Mice DO have much longer telomeres AND do lose them much faster BUT don't run out of telomeres for 4+ generations (in TERT mutant knockouts).

The relevant part in aging is probably the rate of telomere loss part however, and of course the higher ROS levels I mentioned.

https://www.cell.com...3X?showall=true

Edited by QuestforLife, 02 November 2018 - 08:19 PM.

[xEva]

thank you Quest that's the study. Still, it does not clarify the issue with our favorite assumption, because:

quote:

we observe a strong correlation between the rate of increase in the percentage of short telomeres and longevity (Figure S3). These findings indicate that the rate of increase in the percentage of short telomeres is a robust and reliable telomere marker for longevity studies.

 

Also, they set the cutoff for short telomeres at 15 kb, which happens to be the average telomere length in "young humans" (young mice have ~50 kb long telomeres). <-- this is a crucial point! 

 

And so, when a certain percentage of mouse telomeres become short -- even though they are still long compared with those of humans -- for the mouse, they are short and affect its longevity negatively.  

 

My takehome from this is that short telomeres matter for both mice and humans, even though what is considered short, in absolute kb, differs for each species.  So it seems that saying that "mice have long telomeres and therefore telomere length does not matter" is wrong, because the absolute values in kb are not comparable.

Edited by xEva, 02 November 2018 - 10:28 PM.

[QuestforLife]

I agree xEva. Telomere length does matter, but the point people are often confused about is replicative senescence. Mouse cells generally do not reach the point where they are arrested due to short telomeres. So people think telomere shortening cannot contribute to mice aging.

But what most do not realise is that cells gradually get slower, both in their replication and turnover of internal proteins, as telomeres get shorter. Until they finally stop at the replicative limit. It is more of an analogue change in functionality rather than a sudden change from functional cell to senescent one.

Given the higher ROS levels produced by mouse cells it then become obvious how telomeres getting shorter can lead to senescence induced by unrepaired ROS damage - proteins and lipids within cells are more and more damaged until cells become senescent through 'non telomeric' pathways.

There are also papers from Shay and Wright showing gene expression is changed as the telomere tail shortens through a chromatin and DNA folding mechanism, and this may play a part in the increased induction of senescence.

Edited by QuestforLife, 03 November 2018 - 08:59 AM.

[Turnbuckle]

thank you Quest that's the study. Still, it does not clarify the issue with our favorite assumption, because:

quote:

we observe a strong correlation between the rate of increase in the percentage of short telomeres and longevity (Figure S3). These findings indicate that the rate of increase in the percentage of short telomeres is a robust and reliable telomere marker for longevity studies.

 

Also, they set the cutoff for short telomeres at 15 kb, which happens to be the average telomere length in "young humans" (young mice have ~50 kb long telomeres). <-- this is a crucial point! 

 

And so, when a certain percentage of mouse telomeres become short -- even though they are still long compared with those of humans -- for the mouse, they are short and affect its longevity negatively.  

 

My takehome from this is that short telomeres matter for both mice and humans, even though what is considered short, in absolute kb, differs for each species.  So it seems that saying that "mice have long telomeres and therefore telomere length does not matter" is wrong, because the absolute values in kb are not comparable.

 

 

Note that the correlation is not with short telomeres per se, but the rate of build up. So what causes short telomeres to build up more rapidly? Is it greater ROS? Or a faster turnover of cells, thus increasing the epigenetic age of those cells? Or a failure of apoptosis to efficiently eliminate cells with short telomeres? In any of these cases the rate of increase in short telomeres would be a symptom, not a cause.

[QuestforLife]

Well the point of the study was to show that mouse telomeres shortened dramatically during their lifespan, and they picked an arbitrary cut off of 15kb to denote 'short'. Even though they didn't reach replicative senescence.

It may well be that larger animals need shorter telomeres to preclude the accumulation of mutations and possibly epimutations in those cell lines. The other half of the equation of course is the metabolic rate of those cells. I read a study that showed human DNA in a mouse cell accumulated epigenetic changes as fast as mouse DNA. So there is no doubt that mTOR, ROS, etc. are very important to the rate at which these various age related changes (telomere length, methylation, senescent cells, etc.) accumulate. The fact that mice have long telomeres and a fast metabolism and high ROS implies all these changes should accumulate quicker than in humans, which is what we see.

Edited by QuestforLife, 03 November 2018 - 01:52 PM.

[Brian Valerie]

I thought it couldn't hurt to add information from my own just completed five day, rather high dose (at least compared to what could be ingested in food) trial of fisetin to the thread.  I refrained from all other supplements, with the exception of 400 mg daily of SAM-e shortly after arising, on the admittedly small chance that SAM-e might provide some protection just in case of any liver toxicity.  I took 600 mg of fisetin daily, one hour prior to breaking my usual 14 to 16 hour "time restricted feeding" overnight fast.  My breakfasts did include generous amounts of black pepper (piperine) as a seasoning, and canned pineapple with its juice (bromelain) for dessert, in the perhaps vain hope of modestly improving fisetin's bioavailability, but not to the point of mega-dosing myself beyond fisetin's excellent safety profile, which I believe may indeed be based on its low bioavailability.  The information that I have to share is that I was unable to notice any changes whatsoever in myself that would not be more reasonably attributed to the previous night's amount of sleep, which also remained within my usual 6.5 to 8 hour range.

At the risk of sounding paternalistic or even condescending (that truly is not my intent), I'd like to remind our younger readers that the risk versus reward ratio for this or many other relatively untested anti-aging protocols may not be favorable for people who haven't yet at least reached middle-age.  Just because we early adopters of an episodic, high dose fisetin protocol weren't aware of any adverse effects, does not mean that there couldn't be such effects.  Please be patient, youngsters.  Adopt a healthful lifestyle, avoid unnecessary risks, and await further research.  You have time!    

[Decimus]

I have also run a course of fisetin.  I took 1000 mg for five days.  I had no side effect but, no noticeable positive effects.  I strongly question its bioavailability or translation of positive effects into humans for two anecdotal reasons.  One, I took dasatinib with quercetin a few years ago and had truly astonishing results.  I smoked for a decade in my youth and after taking the das+q my lungs felt liked they cleared out a lot of damage.  My breathing became smoother.  My lung capacity felt like it increased.  I could go longer with greater ease doing cardio.  The effects happened within 24 hours.  For the record, I ran the same protocol a year later and it had no effect whatsoever, so the areas it was going to reach and benefit it did and then it plateaued.        

 

The second reason, is that while in a middle-aged person like myself you would expect to see ambiguous results, some of the people here who are experimenting with this appear to be over 60 (I am guessing) and in that cohort you would expect to see at least some noticeable metric of improvement.  From what I have seen no one has noticed anything of particular note.  

[ambivalent]

I would mix it with olive oil as another poster suggested to improve bioavailability - I took three grams in OO. The overnight cessation of my allergic cough and subsequent non coughing response to alcohol were very clear effects (it has returned somewhat but still 75% off). There were other effects noticed which I mentioned in a previous post. 

[Harkijn]

Not  quite about senolytics but close enough:

https://www.scienced...81113141814.htm

[OP2040]

Not  quite about senolytics but close enough:

https://www.scienced...81113141814.htm

 

Ya I just read this as well.  These types of studies have me questioning whether I should be taking this consistently instead of just periodic mega-doses.  In one of the studies they reference here, the mice were given Fisetin daily for relatively long periods.  It has be affecting other pathways aside from senescent cells.   In this particular case it was targeting an inflammatory pathway.

 

For the folks taking this daily, how much do you take, what time, with food or not, and what is your main motivation for doing so?

[Harkijn]

Since about 50 days I am taking a combi supplement containing NR, Resveratrol, Quercetin and also Fisetin and some other polyphenols. In order to get at 500mg NR/day I take two capsules (= double daily serving) per day, which means that I take 20mg Fisetin per day. I take the two capsules early in the morning because NR is thought to be better absorbed in an empty stomach by some.

This supplement is expensive so I don't know if I can keep on  buying it, but I am seeing some subjective positive  developments lately. They might be attributed to all of the substances I mentioned, or some others I take, or to some other unknown factor. I'll post more about this in the NR Personal Experiences thread in about ten days.

I am interested in trying a senolytic dose of Fisetin  but I was a bit late in ordering pure Fisetin and now I may receive some Fisetin end december....

Edited by Harkijn, 14 November 2018 - 04:17 PM.

[OP2040]

Ya, expense is always a big thing.  My way of mitigating expenses is to try and limit my supplement regime to one (or two at most) per Hallmark of aging.  And choose the best possible supplement for that class based on the latest research, which for me would be Fisetin for the senescent cell class.  NMN covers a couple hallmarks, so that helps.  But having said that, there is so much research and so many possibilities, it is hard to keep it down to a handful. 

[Mike1024]

Harkijn,

 

In place of NR, consider using cheap time release niacinamide. The time release form reduces the niacinamide peak concentration so any inhibition of SIRT1 should be minimal.  Both 500 mg and 1500 mg time release pills can be found on Amazon (US).

[Nate-2004]

I'm in the middle of a D+Q+F+A quadruple attack during my 5 day fast. (Dasatinib+Quercetin+Fisetin+Apigenin)

 

Amounts I'm taking:

 

The fisetin is 1g

The quercetin is 150mg EMIQ plus 500mg regular

The apigenin is 100mg (due to reported 11mg per 100mg bioavailability) 

The dasatinib is 50mg

 

I am adding just a small TSP of MCT to the cocktail in hopes of improving bioavailability without breaking the fast.

 

Honestly though, I don't know if the latter three are even bioavailable enough (especially without fats or food) to have any kind of actual effect on senescent cells in vivo for humans. It's an experiment, only doing it for three of the 5 days, so we shall see.

Edited by Nate-2004, 14 November 2018 - 09:31 PM.

[Rocket]

'Senescent cells, however, are not all bad, and evidence shows that they play a role in cellular reprogramming [16] and wound healing. Like all things in biology, it is therefore clearly a question of balance: too much clearance of senescent cells would be bad for wound healing and cellular reprogramming, but too many senescent cells lead to damage'

https://www.leafscie...org/senolytics/

Do fetuses or newborns have senescent cells? They seem to do just fine without them building up in their bodies.

[Rocket]

I'm in the middle of a D+Q+F+A quadruple attack during my 5 day fast. (Dasatinib+Quercetin+Fisetin+Apigenin)

Amounts I'm taking:

The fisetin is 1g
The quercetin is 150mg EMIQ plus 500mg regular
The apigenin is 100mg (due to reported 11mg per 100mg bioavailability)
The dasatinib is 50mg

I am adding just a small TSP of MCT to the cocktail in hopes of improving bioavailability without breaking the fast.

Honestly though, I don't know if the latter three are even bioavailable enough (especially without fats or food) to have any kind of actual effect on senescent cells in vivo for humans. It's an experiment, only doing it for three of the 5 days, so we shall see.

The dasatinib is low. 2 days of 200 to 250mg each.

[able]

I have been taking large dosages once a week, alternating between Fisetin and Curcumin.

 

No notable negative side effects.  A bit queasy sometimes for an hour or two after injesting.

 

No provable positive benefits, as I haven't been measuring anything.  Subjectively, I feel great the day after, and better every week.  Obviously cant rule out placebo effect, or some other changes in my exercise or diet, or just random variation.   But if I had to bet, I believe I am seeing benefit.

 

Here's the dosage I have been taking:

 

Fisetin - Doctors Best 100 mg capsules with 30 per bottle.  Opened 60 capsules (6 grams) and mixed with olive or MCT oil.

 

Curcumin - Ultracure - 120 capsules of 500 mg each per bottle.  Swallowed 40 capsules (20 grams) with some olive oil.

 

I did use smaller dosages the first time, with no noticeable problems.  Then used the dosages above twice each so far (once per week, alternating)

 

I know the fisetin study showed great results from single dosage and it is enticing to thing we might be able to take something once per month or a few times a year.  I have been using once a week as I have no way of knowing what % of senescent cells might have been removed.

 

Anyways, just wanted to share that I have been using some large dosages without noticeable negative side effects.   I have added large dosage of NMN prior to this routine to try and protect liver from any damage.

[OP2040]

Do fetuses or newborns have senescent cells? They seem to do just fine without them building up in their bodies.

 

We shouldn't just assume that they don't, what with so many other surprising findings.  But I think you're right, and people confuse the fact that fetuses use apoptosis quite extensively for quickly remodeling fast growing tissue.  The difference being that said cells are also quickly cleared away.  An important question would be whether they stick around long enough to have an effect on the tissue micro-environment through signaling, as this is a known function of senescent cells for adults.  Maybe the whole process is just quicker and the cells undergoing apoptosis do have important signaling affects.  Open questions as far as I know.

[QuestforLife]

Do fetuses or newborns have senescent cells? They seem to do just fine without them building up in their bodies.

Yes, and they're very important to development.

https://www.ncbi.nlm...les/PMC4594451/

Abstract
Cellular senescence is an irreversible form of cell cycle arrest that has been linked to several pathological conditions. In particular, senescence can function as a tumor suppressor mechanism, but is also thought to contribute to organismal aging. Paradoxically however, through the secretion of various factors, collectively termed the senescence-associated secretory phenotype (SASP), senescent cells can also have tumor-promoting and tissue-remodeling functions. In addition, senescent cells can play beneficial roles in tissue repair and wound healing, and reconciling these contradictory features from an evolutionary standpoint has been challenging. Moreover, senescent cells had not previously been documented in non-pathological conditions. Recently however, 2 studies have identified cellular senescence as a programmed mechanism that contributes to tissue patterning and remodeling during normal embryonic development. These findings have significant implications for our understanding of cellular senescence and help to clarify the paradoxes and the evolutionary origin of this process.

Edited by QuestforLife, 15 November 2018 - 02:23 PM.

[sthira]

Anyone know if one of the biotechs is experimenting with shoving fisetin molecules into tiny tubes (senescence-associated beta-galactosidase enzymes) for targeted strawberry-delivery into zombie cells?

Which type of senescent cell does fisetin attack, hopefully not head and heart: "Cuz let me take you down/Cause I'm going to Strawberry Fields/Nothing is real/And nothing to get hung about/Strawberry Fields forever" I bet John Lennon knew how to cap and release strawberry fields into zombie cells, he wrote a song about it, right?

[theone]

What’s more, scientists were able to cause young, healthy cells to stop dividing by heightening CD36 activity within those cells. The effect spread to nearby cells, with almost all of the cells in a petri dish showing signs of senescence when only a small fraction of those cells — about 10 to 15 percent — were overexpressing CD36. New cells placed in the growth medium (a soupy substance) that previously housed the senescent cells also stopped replicating.

 

 

This seems to lead to some type of cascading effect.   As we age  the bodies "soupy substance"  may increase senescent cells all on it's own.  This may also offer a partial explanation to the benefits of young blood (a better soupy substance).

 

Have we identified any long lived mammals that don't accumulate senescent cells?

 

 

http://www.buffalo.e...018/06/011.html

 

 

Edited by theone, 15 November 2018 - 09:41 PM.