Human blood cells can be directly reprogrammed into neural stem cells | Hacker News Reader

Human blood cells can be directly reprogrammed into neural stem cells

dkfz.de

421 pointsmyinnerbanjo37 comments

I was directed to ask these questions here. Perhaps someone can help.

>They can be modified and multiplied indefinitely in the culture dish

What conditions exist within a culture that allow stem cells (or other cells) to replicate without regard for the Hayflick limit? I was totally unaware that we had extended it (not defeated it) in any life more complex than a worm. And on the topic of the Hayflick limit…

>What is special about the reprogrammed cells of the Heidelberg researchers is that they are a homogeneous cell type that resembles a stage of neural stem cells that occurs during the embryonic development of the nervous system.

Are they saying that the stem cells can be reprogrammed into cells that more greatly resemble younger human cells, or that they're actually being made into scientifically-defined younger cells? How is that even possible? I was under the impression that all cloned cells retained their telomerase length. As such, any clone (or cloned tissue) made from them isn't going to be any more "youthful" than the original. If the case is that an entirely cloned organism is made, it will only a life expectancy as long as the original has LEFT to live–since the telomere isn't restored to its original length.

I guess they wouldn't call it a "regenerative" therapy if they hadn't fixed the telomere length problem in the cloned cells, but… if they have, isn't that sort of the single biggest fucking deal in human history? Isn't this the first time that human cells have been genuinely restored to youth, and could therefore be reapplied into a person to extend his life? And, thereafter, be the gateway into figuring out how to simply restore the DNA of cells in the body without excision and replacement?

Thanks for any answers!

Oh dear, I may have double posted. Sorry if I did.

I wish I had an answer for you, but I don't. Just dropping in to say that KS for asking those questions, as I didn't even know of the Hayflick limit before.

I now have more questions.

Many types of human-cells don't abide by the classic Hayflick limit, including HeLa cells, cancer cells, and gametes.

This brings up the point: if the cells can indeed divide indefinitely, which even stem cells cannot, then aren't these effectively cancer cells / made cancerified? Perhaps this was done on purpose independently to make the cell culture easier to work with, but that should have been mentioned.

They might share some properties with cancer cells, but probably not all the key characteristics.

For example, one key feature of a cancer cell is that it ignores signals that would causes normal cells to stop growing or apoptose (die).

My understanding of it is (although I'm not remotely an expert on cell culture) that stem cells can in general be made to divide in culture "indefinitely"; the Hayflick limit applies only to (non-stem) somatic cells. Stem cells use telomerase to maintain their telomeres, similar to how germ cells use telomerase to reset themselves to a "newborn" state.

Stem cells can progress from "universal progenitors," the stuff of the featureless blastocyst, to embryonic stem cells of various forms, to adult cells (both stem and somatic); this process has to do with changes in gene activation and cell morphology, not with telomeres. When the article notes that these cells can be "multiplied indefinitely," the point is that researchers can prevent them from differentiating into more-mature forms of cell when they divide.

This is very uplifting news! This makes me feel very hopeful about the future, too.

I personally have 2 rare autoimmune neurological diseases that affect my peripheral nervous system. One of them is very rare, and there is only case reports and cohorts of it, at best, in the medical literature.

There will likely never be an FDA-approved treatment for what I have, and this is why precision medicine needs to exist formally, with proper regulation via government. Unfortunately, the United States government has not been adapting, in a progressive way, to the changing times, with respect to emerging technologies, in general.

This sounds strange, but the lack of a reforming/progressive government is the greatest threat to my well being with rare neurological diseases and being disabled.

I hope that therapies and cures can come sooner than later for everyone. I also hope these therapies are not prohibitively expensive or inaccessible.

It looks like this builds on the 2007 and 2012 publications.

> Scientists from the German Cancer Research Center (DKFZ) and the stem cell institute HI-STEM* in Heidelberg have succeeded for the first time in directly reprogramming human blood cells into a previously unknown type of neural stem cell. These induced stem cells are similar to those that occur during the early embryonic development of the central nervous system. They can be modified and multiplied indefinitely in the culture dish and can represent an important basis for the development of regenerative therapies.

When can I inject this and fix my stroke? Hurry please. :)

I'd caution against randomly re-wiring chunks of your CNS. There's probably a very good reason why we don't naturally do that.

Depends. Could be good long term, I suppose, but might require a long hospital visit even in the case of a good outcome. Enough for evolution to prune it.

I'd caution against randomly flying across cities. There's probably a very good reason why we don't naturally do that.

Just pointing out that this is a weak argument.

You might wait for a few flights over an empty field first though.

Many people were injured or killed trying to invent flying machines until we finally got it right.

Many many people have already died of brains issues. On the order of 5% of everyone who has lived ever. Esp in the last 2 centuries which from some counts is more than ever lived before.

Your simile would be apt if people not getting to the other side of the city were dying or having greatly decreased quality of life (alzheimers, stroke).

The chunk I’m worried about probably can’t get much worse (it’s dead).

If the rest of your system has adapted to assume that a certain address space is non-executable, suddenly making it executable might cause a bit of a headache.

If it's adapted once surely it can adapt again?

Things like strokes or cumulative CNS damage primarily affect older people, so genetic fixes to those problems would have very little evolutionary selection pressure on their side.

It's also possible that genetic/biological means of turning on CNS regeneration in higher mammals would require a complexity that has not had time to evolve yet. Just because we evolved to the point of human-level intelligence doesn't mean we are perfectly evolved by any stretch of the imagination. It means we are, in a sense, a minimum viable biological entity that can acquire our level of intelligence.

I remember reading an article on neuroplasticity into old age. And people with extremely high neuroplasticity had better cognitive function throughout their lives however were much more likely to have dementia in old age. It's probably similar I'd guess.

Medicine is all about doing things that we don't do naturally. If we did it naturally we wouldn't need doctors.

Unfortunately generating additional neurons and rewiring neurons to replace brain chunks may be separate problems.

This seems like a pretty sick burn but I am not a neurologist

Pretty sure it wasn't, but it struck me that way also XD.

Hurry up and fix my optic nerve too while you're at it :)

Given how lame medical research is, don’t expect any therapies for at least 10 years.

I thought blood cells shed their nucleus?

Red blood cells do. Leukocytes are nucleated.

What happens to the telomeres?

I wouldn't worry too much, neurons don't divide indefinitely.

Is this something that occurs naturally? As in, are there normal pathways by which cells change their types in beneficial ways?

Yes, it happens all the time, but at a low enough rate that for a long time it wasn’t observed

* who knows if it is beneficial

An analogous manifestation can be triggered by drilling holes in the kneecap allowing blood to move into damaged cartilage (say, below a kneecap). In the new environment, some of the red blood cells apparently transform into cartilagenous cells and repair the cartilage. Some doctors in sports physiology were doing this decades ago. No significant pressure can be put on the knee for 3-6 months but the solution was well worth it to the individual with whom I spoke.

So it seems that it is likely a natural/normal method of repair although it may be very slow w/o some prompting (drilling the holes, in this example).

A newer technique that sounds very similar but more general is P.R.P. (Platelet Rich Plasma) therapy:

New Yorker: "The Blood Injections That Might Transform Orthopedics"(2013)

https://www.newyorker.com/tech/annals-of-technology/the-bloo...

This has been around for quite some time. 2007 publication by Yamanaka, and then 2012 by Weissman/Wernig et all.

Would this be an argument against umbilical cord banks ?

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