3 ms·
Wikipedia: "Essentially, CFTR is an ion channel that evolved as a 'broken' ABC transporter that leaks when in open conformation." You: "That is interesting to
by hga 11y ago
Wikipedia: "Essentially, CFTR is an ion channel that evolved as a 'broken' ABC transporter that leaks when in open conformation."
You: "That is interesting to me. CF is basically a salt-wasting condition. There are various forms of defect in the CFTR, but knowing that it basically leaks may explain why it is basically a salt wasting condition."
Errr, that was referring to normal CFTR. The class of proteins it belongs to normally require ATP, the ready energy source in cells, to actively transport stuff, e.g. use up one molecule of ATP to transport one molecule of whatever. CFTR is 'broken' in that it looks a whole lot like one of these proteins, but instead of ATP being used to transport a molecule, i.e. against an osmotic gradient, the ATP just "opens its door" (or the reverse, I didn't check), and then ions and water go whichever way the gradient favors. I.e. if there's lots more water in the cell than outside the cell, it goes out.
So one of the things I found was that there are two conditions that cause higher misfolds of proteins within the cell: Derangement of PH level and derangement of salt level. You see both of these things happening with CF.
Ah, I see where there's usefulness here, given the variety of CFTR mutations (and note that one person might have two different mutations, one contributed from each parent, or arising from very early stage embryo mutations). There will be mutations that as you describe, where if you can adjust the conditions under which the protein is created and initially folds, and or preforms afterwards, you get a more favorable outcome.
As for acid, well, it depends on where the acid is. Acidosis is a condition outside the cell, per the Merck Manual "Acidosis is excessive blood acidity caused by an overabundance of acid in the blood or a loss of bicarbonate from the blood (metabolic acidosis), or by a buildup of carbon dioxide in the blood that results from poor lung function or slow breathing (respiratory acidosis)."
So to refine your hypothesis, once the protein is in the cell membrane, a greater concentration of hydronium ions (https://en.wikipedia.org/wiki/Hydronium https://en.wikipedia.org/wiki/Hydronium) outside will damage it. And if the outside is more acid than the cell, they'll flow in through the channel, where they can donate a proton (bare hydrogen atom), doing mischief to CFTR or even the cell.
So I have concluded that there is a vicious positive feedback loop where the more acid you get, the more you see protein misfolds and the more you see protein misfolds, the more acid you get. I believe this is why it is a degenerative, progressive condition.
That would only happen if your as blood gets more acid, it stays more acid, but short of requiring intervention. Note also that proteins tend to? often? have have a life cycle, they get produced, work for a while, often get zapped one way or another, and then get recycled. That mutation class I mentioned of premature degradation implies this is true for CTFR; the cell would fail to keep up production sufficient to counter that. Note also there should be a signaling mechanism that tells the cell to produce more or less of CTFR, I'm assuming that even if the signal is "I really need more!", the cell has a limit to how much it can produce, and still survive, it can't under-produce other vital stuff too much ... and that also might have an effect.
Sounds like there's cumulative damage elsewhere that can't be reversed in this way, e.g. the stated pancreas scarring that causes Type 1 diabetes, or the classic clubbed fingers per the Wikipedia picture.
But most people with CF are prescribed a high salt, high fat, high calorie diet. This means they are actively encouraged by medical professionals to eat a junk food diet. I went the other way. I pay very close attention to the quality of my food, not the quantity. I went looking for good quality fats and salts and other foods. I think the current practice of prescribing a junk food diet because it is high in fat and salt without caring that it is low in quality is part of what is killing people with CF.
Well, salt is salt, and it might help to increase the saltiness of your blood (not sure how much that's possible or practical), you'll end up with more salt inside the cells (or that sounds likely, but there are surely other proteins that also can transport salt in and out), and outside the cell, the former probably not so good, the latter perhaps in balance for the best for many people.
More later if you wish when you have time, on this HN topic, or you're welcome to email me (see the address in my account info).
- Mz 11y agoErrr, that was referring to normal CFTR. The class of proteins it belongs to normally require ATP, the ready energy source in cells, to actively transport stuff Yes, but it potentially reconciles the seeming contradiction between the defect causing both a bottleneck and salt wasting. Perhaps that is gibberish, but I have always wondered how a bottleneck can cause salt wasting. As for acid, well, it depends on where the acid is. Acidosis is a condition outside the cell, per the Merck Manual "Acidosis is excessive blood acidity caused by an overabundance of acid in the blood or a loss of bicarbonate from the blood (metabolic acidosis), or by a buildup of carbon dioxide in the blood that results from poor lung function or slow breathing (respiratory acidosis)." Well, that sounds ridiculous to me. People with CF hoard both calcium and glutathione inside the cell. They have too little glutathione outside the cell, so some people inhale NAC to increase glutathione on the lung surface, with good results. I have tried to correct the underlying cause of those imbalances. Given that life did not emerge from the ocean until we had bones, in part because the calcium mediates the blood ph, something not needed for marine animals, and given that people with CF not only hoard calcium inside the cell but are prone to osteoporosis as early as their teens, I believe the body is using calcium and glutathione to buffer the cells against extremes of acidity and other chemical derangement. The body does not allow the blood to get too acid unless there is serious failure somewhere. The body strips the bones of calcium to keep the blood ph within very narrow boundaries because failure to do so quickly results in death. Therefore, it is silly to think of acidosis as something that happens in the blood. By the time the body lets the blood get too acid, something has to have gone very very badly wrong in all the tissues. A few months ago, a woman who has written papers on CF told me I had to be wrong, that CF could not be causing severe acidosis as that would kill you because the cell can only exist within a narrow ph range. I rebutted that with "Given that CF is extremely deadly, I don't think that is a good counterargument." She then found that several years ago, there was clinical research into acidosis and CF that fits with my hypothesis. I posit that the mental model that acidosis is about blood ph is silly and misses a larger issue. That would only happen if your blood gets more acid, stays more acid, and so on. Note also that proteins tend to? often have have a life cycle, they get produced and recycled. That mutation class I mentioned implies this is true for CTFR, that class results in premature degradation, the cell fails to keep up production sufficient to counter that. Note also there should be a signaling mechanism that tells the cell to produce more or less of CTFR, I'm assuming that even if the signal is "not enough!", the cell has a limit to how much it can produce, and still stay alive, it can't under-produce other vital stuff too much. Some of my handwavy recollection is that some drugs are successful in improving production of the CFTR channel and this is known to significantly reduce symptoms. If you can get the body to create more CFTR channels, you can reduce symptoms. This is clinically known and not something I am just imagining. I think it makes logical sense as an explanation for why my condition is so much more stable than I ever expected it to be. :-) Well, salt is salt In theory. In reality, that is a big fat NOPE. There are huge chemical differences between "table salt" which is filled with crap to make it pour easier and "canning or pickling salt" and "high brine sea salt." There are very huge chemical and qualitative differences. These differences multiply (or at least their impact on the body does) when you have a salt wasting condition and must consume higher than normal amounts of it. I stopped consuming table salt some years ago. I think it makes an excellent non-toxic household cleaner. I do not view it as edible. My email is also in my profile if you wish to continue the discussion there.