29 replies to this topic

[manofsan]

Here's an article:

http://www.betterhum...ID=2004-11-15-3

So telomerase helps immune cells keep multiplying. Sounds good, but what happens if you get some sort of lymphatic cancer, or uncontrolled immune cell growth?

[olaf.larsson]

Yes the fact that telomerase makes cells replicate indefinitly is not new, but I would like to see an experiment in which an organism is made to live longer by swiching on telomerase production. I have not seen any such expreriment yet and I dont think a complete organism would live longer just becouse it expresses telomerase. One interesting thing is that the cells replicate indefinitly although they still produce the same amount of ROS in their mitochodria as before, some big parts seem to be missing in our understandning of the aging process.

Edited by wolfram, 17 November 2004 - 03:07 PM.

[manofsan]

Hi wolfram, but according to that article, they don't keep replicating indefinitely and do wear down their ability to multiply. That's why they're trying to use the telomerase. (Yes, we all know it keeps the telomeres long)
But my point was that one of the reasons why we don't just use telomerase indiscriminately is because it tags the cells for destruction (telomerase is an oncogene signal, and excess expression will get your cell attacked)

Again, what happens if you come down with lymphatic cancer? Won't the telomerase help it go out of control? Or is that redundant?

[olaf.larsson]

Its clearly written: "We found that the immune cells could divide endlessly"
How could cells divide endlessly? Since the cells are dividing there will be not big accumulation intracellular inprocessable crap. But wouldn´t the ROS causing a constant mutationrate kill the cells? No some cells constantly die becouse of mutations due to ROS etc., but since the rest are replicating it couses the impression of a constantly growing nonsenescent cellculture. If my hypothesis is true cancercells grown on diluted medium, which will prevent them from replicating but support lifefunctions, will after some time accumulate inprocessable crap and mutations, become senescent and die.

Edited by wolfram, 23 November 2004 - 06:35 PM.

[manofsan]

I want to ask more about the unprocessable crap -- I assume we're talking about glycosylation, etc -- the glop that accumulates and gums up your cells eventually.

Now, if your cells are multiplying by dividing and splitting, then does each cell's unprocessable crap get handed down to the new daughter cells?

Where exactly does the crap accumulate and reside? Does the crap just float around freely in the cell, or does it gather somewhere in particular? What does it start to clog first?

Has there ever been any focused effort to analyse exactly what the crap is? What makes it so unprocessable? Is there any way to make the unprocessable processable?

What is the crap content in the average cell of a 90-year old person, as compared to a 2-year old?

Even if we can't use conventional biochemistry to clean up the unprocessable crap, maybe we can find some other gimmick like nanoparticles or something to mop it up.

I can't believe that the crap is totally unbeatable.

[olaf.larsson]

The "crap" consists of various biochemicals which by chance have got bonds which make them unsuitable as substates for normal enzymes. One place where the "crap" accumulates is the lysosome. By cell division the crap becomes diluted so if the division rate of the cells exeeds crap-accumulation the cells will go on dividing as long as their telomeres not become to short. If crapaccumulation exeeds celldivision the crap will impair cellfunction. Look for articles about "lipofuscin" and "A.G.E." to learn more about this "crap".
Some compound have been developed to break up the crapagregates but the results are unsure as I can understand it. One company which develops AGE breakers is Alteon: http://www.alteon.com/

What is your background manofsan?

[manofsan]

I took chemical engineering at University of Waterloo, Canada, but I went into IT as a career. I'd always wanted to study molecular biology, and was accepted to University of Minnesota for undergrad, but my parents didn't let me go because they wanted me nearer to home. So I never felt satisfied with chemical engineering, and always wanted to go back to school to take molecular biology, or even bioinformatics.

Yes, I understand fully that the residue "crap" is not actionable by our known set of conventional enzymes, but perhaps further efforts should focus on targetting the lysosomes then, to break down and/or transport their contents out of the cell.

I'd always thought that lysosomes are used purely to house the lysing agents used for cell suicide.

If crap accumulates in the lysosomes, then could there be any way to specifically target the lysosomes with crap-o-philic molecules that would bind to it, and help us take it out of the cell?

Just like the mitochondrial targetting we were talking about earlier, I presume the lysosomes might have some uniqueness to their membranes that might enable specific targetting of them. Are lysosomal membranes different from other membranes in any way?

[olaf.larsson]

One possiblity would be to try to grow various bacteria on extracted lysosomal crap and analyse which enzymes are used to process the crap. The genes for the enzymes could then be inserted by genetheraphy in various cells after beeing added lysosomal targeting sequence. The idea that bacteria should have this enzymes is mr. de Greys. As mr. de Grey pointed out lysosomal crap doesn´t seem to accumulate in graveyard where dead people lie, so it must be processed somehow.

[manofsan]

Well, is the residue one homogenous substance, or is it more likely a collection of different substances?

Well, one man's drink is another man's poison, and vice versa.

So once the composition of the metabolic residue is determined, then I'm sure some organism and enzymes can be found that can act on the stuff.

Maybe we'd need to do some sort of specialized targetting, binding the enzyme to some molecule that will seek out the lysosomes.

I'm going to post more on this "supertargetting" stuff, because it seems like an entirely better approach, whereby you are specifically targetting an organelle/structure for your drug/molecule to get to. Especially when the target is in some enclosed compartment like a mitochondria or nucleus or lysosome, you want something that will get you past the barriers.

[olaf.larsson]

Yes ofcourse the junk is not consisting of an astronomical number of strange molecules in chaotic order. It could be analysed and cathegorised.

[manofsan]

Gee, I feel so unclean and bloated, now that I've realized I'm full of all this residue. Blech.

So this residue is just piling up, and the only way we were able to escape the consequences of that, has been to keep our cells multiplying fast enough to dilute or spread out the accumulating gunk. As soon as we stop bringing in more cells, it all catches up to us.

Our body is based on a pyramid scheme!!! :(
That's illegal!

We need to bring some fiscal rectitude to our metabolism.

[olaf.larsson]

"So this residue is just piling up, and the only way we were able to escape the consequences of that, has been to keep our cells multiplying fast enough to dilute or spread out the accumulating gunk."

Yup. My teacher in cancerbiology has confirmed that even cancercells finaly die if they are kept on strict diet enough to supply lifefunctions but not cellmultiplication. Before a teacher in microbiology has confirmed that the same happens to bacteria. Non of them knew that that has to do with inprocessable-cellular-junk accumulation.

Edited by wolfram, 24 November 2004 - 04:22 PM.

[manofsan]

Yeah, but that sounds like a different issue. Multiplication is something that you do when you have taken care of your basic food needs. But if you're only getting enough food to get by on, then you will use that for your basic survival, and will have to put off reproduction. Caloric intake restriction is used to minimize your metabolism, which then extends life due to reduced production rate of the junk byproducts.

[olaf.larsson]

I mean: When cancercells are prevented from replicating becouse of minimal diet they are after some time unable to divide even if supplied with full diet. As I see it it is becouse of junk accumulation.

[manofsan]

Hey, that's an interesting hypothesis, but what about testing it out on regular bacteria/protozoa? From what you've said, these non-telomeric creatures should still suffer the same problem. If you keep them on starvation diet, then they'll just survive and not reproduce, and later on when you buff up their food supply they should have the same difficulty in reproducing.

I thought the gunk is supposed to damage a cell's metabolic efficiency, and not necessarily its ability to further reproduce. I thought the reproduction outlet is a way to escape the effects of gunk accumulation by apportioning it among the kids.

Still sounds like a pyramid scheme to me.

A way is needed to track this gunk in the first place, perhaps using fluorescent and other biomarkers, and then you can see how much gunk is accumulating and where.

Then I would see if there are other creatures in the biological world that are capable of metabolizing this gunk -- like the graveyard example you gave. Then we have to find out what biochemical mechanism they use. Then we have to perform the same trick on our own cells, even if only thru ingested drugs.

[olaf.larsson]

"I thought the reproduction outlet is a way to escape the effects of gunk accumulation by apportioning it among the kids."

Man how much inprocessable junk could you fit in a sperm or an egg. 99,9999999999 % stays in you. For unicellular organisms is diffrent since both mothercell and doughter cell are about the same size.

Then ofcourse we have the mutations which kill cells but we dont have to worry much about them if we have other cells still replicating which can replace cells which have died due to mutations.

The junk from dead cells has nowhere to go, its probably eaten by macrofages which can not process it and die themselves.

From logical of view its not strange. Why would the organism have enzymes to process molecules that are dangerous for the individual but only accumulate in so tiny amounts over time so that they are not a threath to gene propagation? There is no need for it, at least not from the genes point of view.

[rshack]

Interesting conversation. One aspect of the cellular "crap", i.e., lipofuscin is that it contains glycosylated proteins, lipid peroxides, and iron. The iron is losely bound to the lipofuscin and therefore can catalyze Fenton chemitsry (H202 + Fe2+ --> Fe3+ + hydroxyl radical). Thus at a certain point lipofuscin becomes a very powerful oxidant and creates a positive feedback loop for more opxidative stress, lipofuscin production, and cellular damage. Added to this are the increased reactive oxygen species accerate telomere shortening and mitochondrial genome mutations. This lipofuscin accumulation also increases at a time in life (about the mid-40's), where DNA repair systems become less efficient. Well, as previuously pointed out, our bodies are selected by evolution to last long enough to produce children that can survive on their own. After that point, there is little or not selection for viability and senescence-associated degenerative changes rapidly appear.

[olaf.larsson]

Is all inprocessable crap acctually lipofuscin or is there more? If you define lipofuscin as inprocessable crap, indeed all inprocessable crap will be lipofuscin.
How about the A.G.E products are they to be considered to be a part of lipofuscin or are they to be considered as "non- lipofuscin-crap".

You seem to know much about this rshack what is your background..?

[rshack]

There are several different types of waste that build up in cells. Lipofuscin is one of them. It's made up mainly of glycosylated proteins (AGE products attatched to proteins) and lipids, which can also be glycosylated. Almost anything can be glycosylted in the body and "AGE products" is really a biochemical description of how this "crap" is made and how it builds up.

Lipofuscin has until recently mainly been defined by it's light microscopic appearance and biochemcial analyses of its composition are fairly recent. Under H&E it's a very light yellow pigment, easiest to see in neural and hepatic cells. It's mainly proteins and lipids, but can have many other components, such nulceic acids. Lipofuscin builds up in neural cells, but not in hepatocytes. Hepatocytes have a way of secreting lipofuscin into the blood stream where it can eventually be removed by the kidneys. There are people trying to find ways to "teach" neural cells how to secret lipofuscin. I don't know much about how far this work has gone.

The other main pigment that accumulates with aging is hemosiderin, but there are many other. For example, elastin tends to break down with age and collagen levels tend to increase, making older tisse more fibrous and less flexible. These changes have sometimes been called "age-associated wastes" piling up.

My background is a Ph.D. and I recently graduated from medical school. Now I'm a second year pathology resident. I like medical research and am interested in DNA repair, specifically the activity of a gene mutated in the rare disease ataxia-telangiectasia. I'm interested in how this gene, a kinase, can be pharmacologically activated by supplements to increase DNA repair.....and therefore slow the appearance of all the diseases that come with aging. Aging interests me as all the problems that come with it cause so much human suffering and the costs of trying to treat these diseases is enormous and breaking our health care system. I think something could be done about this problem. Or at least I hope so.

[manofsan]

Are there any known agents that can act on lipofuscin? You said that "at a certain point lipfuscin becomes a very powerful oxidant" -- is there any way of disrupting that runaway loop?

Hmm, if the hepatic cells can dump it, then perhaps other cells can be taught to. I wonder why other cells have never developed this ability, and why neural cells in particular have. Is it because of the criticality of neural cells relative to other cells?

[olaf.larsson]

About telomerase again.. I cant believe that there really are so many genuine bioscientist who acctually are going around with the popular view that the whole immortality thing is about about extending telomeres. I have met many of them. When they start talking about telomerase I think Oooh nooooo...
I have only read only about 250 papers about senescence and my conclusion from those is that senescence is primary caused by accumulation inprocessable biomolecules in various combinations.

[rshack]

To answer and earlier question. I haven't seen any ways to increases waste or lipofuscin removal other than caloric restriction. Caloric restriction increases catabolism in general, as well as reduces lipofuscin accumulation and increases its slow removal. The only way I can think of lessening its activity as an oxidant would be to take an iron chelator. EGCG, found in green tea is the only one I know of that is orally active, crosses the blood-brain barrier, and is readily available.

To wolfram above. Good point. Telomeres grow smaller with each cells division. Therefore, if all that mattered were telomere length, neurons would never grow old as they almost never divide. In fact, due to their high lipid surface area, poor iron storing ability, and very high oxidative metabolism , they age like any other non-dividing cell type and are very sensitive to oxidative stress/oygen deprevation.

[manofsan]

Would anyone care to rank the bad improcessible molecules in order of importance? (ie. in order of how harmful they are)

I would wonder if there isn't some artificial way to supplement lipofuscin removal or breakdown.

[manofsan]

Which is cause, and which is effect? Is lipofuscin accumulation the result of some other deterioration, or is lipofuscin buildup beyond a certain point causing an inability to further remove it?

Are there any known pathological diseases associated with lipofuscin buildup? (other than regular aging)
Perhaps some identifiable disease caused by accelerated lipofuscin buildup?

[manofsan]

Hmm, so I was just reading about this Batten's Disease or NCL (neuronal ceroid
lipofuscinoses), and I was reading the following link

http://www.medhelp.org/lib/batten.htm

Some scientists are investigating the theory that children
with Batten disease have a shortage of a key body enzyme.
Investigators are searching for enzymes that might be
scarce, defective, or completely missing. One team of
scientists, for example, is testing the theory that a
specific enzyme, called phospholipase A1, is deficient in
people with Batten disease. Such studies could also prove
useful in better diagnosis of patients. In addition,
identifying an enzyme at fault might make it possible to
treat affected children with natural or synthetic enzymes
that would counter-act the shortage and clear away stored
material. In fact, NINDS scientists have used this approach
to successfully treat another storage disorder known as
Gaucher's disease.

So can this phospholipase A1 be imitated through a drug or other chemical substance? Hey, remember how they found out that simple turmeric can help people with cystic fibrosis?

Hmm, some more info:

using
animal models of NCL, has found that a large portion of this
built-up material is a protein called subunit c. This protein
is normally found inside the cell's mitochondria,
small structures that produce the energy cells need to
do their jobs. Scientists are now working to
understand what role this protein may play in NCL,
including how this protein winds up in the wrong
location and accumulates inside diseased cells. Other
investigators are also examining deposits to identify
the other molecules they contain.

So mito material is building up to clog the cell? Does it mean this subunitC is being produced in excess, or does it mean that the mito is not using the normal amount of it? If mitos are damaged due to ROS, then maybe their uptake of this building material will also be less? I guess I'm trying to understand which is cause and which is effect -- is the buildup of subunitC caused by the deeper problem of the reduced mito functionality, or is the buildup a totally different problem of its own?

[manofsan]

http://www.ncbi.nlm....3&dopt=Abstract

Submitochondrial distribution and delayed proteolysis of subunit c of the H+-transporting ATP-synthase in ovine ceroid-lipofuscinosis.

Hughes SM, Moroni-Rawson P, Jolly RD, Jordan TW.

School of Biological Sciences, Victoria University of Wellington, New Zealand.

The neuronal ceroid-lipofuscinose (NCL) are recessively inherited lysosomal storage diseases in children and animals. The major stored protein in many of these diseases is subunit c of the mitochondrial inner membrane H+-transporting ATP-synthase. Previous studies of naturally occurring ovine ceroid-lipofuscinosis (OCL) in South Hampshire sheep showed that the genes and transcripts for subunit c were normal and inferred that this protein was expressed normally in mitochondria prior to storage in lysosomes. Accumulation in mitochondria has not been conclusively established and we have therefore used the South Hampshire model to demonstrate approximately 1.8-fold normal levels of subunit c in mitochondrial inner membranes prepared from liver. Other mitochondrial inner membrane and ATP-synthase proteins that could be detected by mass spectrometry (MS) or two-dimensional electrophoresis (2-DE) were present in normal amounts. The accumulating subunit c showed normal post-translational modification but was abnormally resistant to proteolysis. These results are consistent with the hypothesis that OCL may result from a mitochondrial disorder that affects turnover of correctly expressed subunit c, although we cannot exclude the possibility that a postmitochondrial defect delays processing of subunit c out of mitochondria.

----

Okay, so if the mito is part of the chain here, whereby it's expected to use up this subunitC as a structural material, then if the mito got damaged by ROS and were to become less efficient in its uptake of the subunitC, then this subunitC could start building up and clogging the cell. That's at least one of the possibilities.

Despite their last sentence about post-mitochondrial problem causing the logjam, the mito does seem a likely common suspect weak point in everything.

Gee, I'd wonder if the MitoQ or Mito Vit E would help the Batten's disease people, like it helps the Ataxia people?

While the subunitC buildup may be correlated to the lipofuscin buildup, do the two substances share any metabolic pathways together? Is there any reason why one would buildup because of the other?

[manofsan]

http://www.ncbi.nlm....t_uids=95397898

Abnormal degradative pathway of mitochondrial ATP synthase subunit c in late infantile neuronal ceroid-lipofuscinosis (Batten disease).

Ezaki J, Wolfe LS, Ishidoh K, Kominami E.

Department of Biochemistry, Juntendo University of School of Medicine, Tokyo, Japan.

Subunit c is normally present as an inner mitochondrial membrane component of the F0 sector of the ATP synthase complex, but in the late infantile form of neuronal ceroid-lipofuscinosis (NCL) it was also found in lysosomes in high concentrations. The rate of degradation of subunit c as measured by pulse-chase and immunoprecipitation showed a marked delay of degradation in patients' fibroblasts with late infantile form of NCL. There were no significant differences between control cells and cells with disease in the degradation of cytochrome oxidase subunit IV, an inner membrane protein of mitochondria. Measurement of labeled subunit c in mitochondrial and lysosomal fractions showed that the accumulation of labeled subunit c in the mitochondrial fraction can be detected before lysosomal appearance of radioactive subunit c, suggesting that subunit c accumulated as a consequence of abnormal catabolism in the mitochondrion and is transferred to lysosomes through an autophagic process. The biosynthetic rate of subunit c and mRNA levels for P1 and P2 genes that code for it were almost the same in both control and patient cells. These findings suggest that a specific failure in the degradation of subunit c after its normal inclusion in mitochondria and its consequent accumulation in lysosomes.

---------

Hmm, so once again, this suggests that the lipofuscin subunitC is accumulating due to the inability of the mitochondria to break it down. Again, this could all be due to ROS damage to the mitochondria. So dysfunctional mitochondria can do more than just produce less energy, they can cause waste buildup in the cell, like this lipofuscin subunitC. These all seem to be mito-related problems.

So as we get older, not only do our damaged mitos become less efficient at producing energy, but also they become less efficient at getting rid of stuff like lipofuscin subunitC. This is the reason why the lipofuscin builds up as we get into our forties.

Regarding conventional aging then, is the only solution simply to avoid mitochondrial damage in the first place, or can these problems be repaired after the fact? Apparently, mitochondria have their own natural method for breaking down the lipofuscin subunitC, and the buildup is due to some impairment of that degradative pathway. Perhaps if the natural enzymes could be artificially created and then transported into the mitochondria via the large lipophilic cation supertargetting method(like MitoQ), then your mitos could clear out some of this lipofuscin buildup.

Or better yet, target the catabolic enzymes at the lysosomes where the buildup is accumulating.

So what you guys said about gunk being improcessible isn't necessarily the case. It's only improcessible because you've lost the processing ability you used to have.
You used to be able to process this stuff when you were young, but as you got older you lost your ability to process the stuff and it started to build up.

[rshack]

I've been away for a while. Here's a neutraceutical "centrophenoxine" that is supposed to remove lipofuscin from the brain. It's sold by an "Offshore Pharmacy". I'll run a MEDLINE on this drug in the next week or two and see if any of the claims made for this drug mean anything. Here's the webpage if it interest anyone:

http://www.smart-dru...rophenoxine.htm

[rshack]

Well, I'm back. it's been a little while. Centrophenoxine is an efficient hydroxyl radical scavenger that works well near membranes. It decreases protein and lipid cross-linking, and increases membrane fluidity and mRNA/protein synthesus in older rodents. There are about 400 papers on it in MEDLINE. It looks interesting and I think I'll see if it can improve function in ataxia-telengeicatasia cells.

[stormheller]

If that centrophenoxine stuff really works, it would be all over the news by now. And you're saying that it only removes lipofuscin from the brain? You need to get rid of those pesky senescifacients all over your body, or else you'll end up as an immortal brain in a jar (LOL).
Of course hypertrophied telomeres are not good for you. You know what that's called? That's right, CANCER. There's really more to apoptosis than telomeres. Sounds like some folks still believe in the Fates and their 'thread of life'.