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My understanding is that stem cells are special because they have the potential to turn into any type of specialized cell the body needs, whereas regular cells

by biot 5y ago

My understanding is that stem cells are special because they have the potential to turn into any type of specialized cell the body needs, whereas regular cells have already turned into specialized cell types and there's no un-frying the egg, as it were. Has there been any research on producing stem cells from specialized cells? Or is there something fundamentally impossible about this, akin to producing the original content given only a hash value?

wswope 5y ago
I haven’t kept up with the latest research, but the term for what you’re asking about is “induced pluripotent stem cells”.
Jedd 5y ago
> Has there been any research on producing stem cells from specialized cells? Unsurprisingly, lots. People have been researching this for a long time, with some famous success stories, eg. https://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly https://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly
- snystrom 5y ago
  For some extra context, Dolly was not made using the iPSC approach (reversing differentiation from adult cells). Dolly was cloned using a process called Somatic Cell Nuclear Transfer, where the nucleus of an adult cell is placed inside an embryo, replacing the embryo's nucleus. The embryo then develops using the DNA of the individual that donated the nucleus. The article kind of alludes poorly to this, but somatic cell nuclear transfer (developed by John Durdon) was a huge milestone in the field that eventually led to Yamanaka's discovery of the pluripotency factors, for which they both won the Nobel prize in 2012.
  - Jedd 5y ago
    That's some excellent context, thank you. I recall when Dolly was in the news, but only understood the broad strokes of the process. I did scan through that page for 'stem', and found a reference to future research, and noted the replication from an 'adult cell' (which I'd assume analogous to differentiated cell). I'd guess the transfer process is why she arrived with shorter telomeres at birth?
    - snystrom 5y ago
      > 'adult cell' (which I'd assume analogous to differentiated cell) That's correct. > I'd guess the transfer process is why she arrived with shorter telomeres at birth? Also spot on. The donor somatic cell likely had shortened telomeres, resulting in shorter length in the embryo. It's kind of an interesting research question, because telomere length gets "restored" for germ cells (otherwise every time an organism produced sperm/eggs the telomeres would shorten), and these types of experiments demonstrate that there is a limit to that restorative process.
snystrom 5y ago
There has been a significant amount of work in this area. One of the most notable breakthroughs was from Shinya Yamanaka (and his lab) in 2006 & onward where they defined a core set of factors that can be expressed in adult cells to convert them back to embryonic stem cell-like states [1,2]. These cells are commonly referred to as induced pluripotent stem cells (abbreviated as iPSC's if you want to google them). There are a bunch of folks working on potential applications of the technology, but as you might imagine, it will take a lot of work the demonstrate safety & efficacy. [1] https://en.wikipedia.org/wiki/Shinya_Yamanaka https://en.wikipedia.org/wiki/Shinya_Yamanaka [2] https://pubmed.ncbi.nlm.nih.gov/16904174/ https://pubmed.ncbi.nlm.nih.gov/16904174/
pkukp9 5y ago
Those types of stem cells can be extremely unstable and carcinogenic even, so yes, the ones that we collect are specialized specifically for either blood or tissue regeneration which is why they are more stable and not inclined to be carcinogenic.
kgin 5y ago
https://www.nature.com/articles/d41587-022-00002-4 https://www.nature.com/articles/d41587-022-00002-4 Even though nobody is quite sure how it works, it's possible to reverse the epigenetics of a cell back to its original differentiated state and even back to stem cell form not entirely unlike rolling back git commits.

by biot 5y ago

wswope 5y ago

I haven’t kept up with the latest research, but the term for what you’re asking about is “induced pluripotent stem cells”.

Jedd 5y ago

> Has there been any research on producing stem cells from specialized cells? Unsurprisingly, lots. People have been researching this for a long time, with some famous success stories, eg. https://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly https://dolly.roslin.ed.ac.uk/facts/the-life-of-dolly

snystrom 5y ago
For some extra context, Dolly was not made using the iPSC approach (reversing differentiation from adult cells). Dolly was cloned using a process called Somatic Cell Nuclear Transfer, where the nucleus of an adult cell is placed inside an embryo, replacing the embryo's nucleus. The embryo then develops using the DNA of the individual that donated the nucleus. The article kind of alludes poorly to this, but somatic cell nuclear transfer (developed by John Durdon) was a huge milestone in the field that eventually led to Yamanaka's discovery of the pluripotency factors, for which they both won the Nobel prize in 2012.
- Jedd 5y ago
  That's some excellent context, thank you. I recall when Dolly was in the news, but only understood the broad strokes of the process. I did scan through that page for 'stem', and found a reference to future research, and noted the replication from an 'adult cell' (which I'd assume analogous to differentiated cell). I'd guess the transfer process is why she arrived with shorter telomeres at birth?
  - snystrom 5y ago
    > 'adult cell' (which I'd assume analogous to differentiated cell) That's correct. > I'd guess the transfer process is why she arrived with shorter telomeres at birth? Also spot on. The donor somatic cell likely had shortened telomeres, resulting in shorter length in the embryo. It's kind of an interesting research question, because telomere length gets "restored" for germ cells (otherwise every time an organism produced sperm/eggs the telomeres would shorten), and these types of experiments demonstrate that there is a limit to that restorative process.

snystrom 5y ago

There has been a significant amount of work in this area. One of the most notable breakthroughs was from Shinya Yamanaka (and his lab) in 2006 & onward where they defined a core set of factors that can be expressed in adult cells to convert them back to embryonic stem cell-like states [1,2]. These cells are commonly referred to as induced pluripotent stem cells (abbreviated as iPSC's if you want to google them). There are a bunch of folks working on potential applications of the technology, but as you might imagine, it will take a lot of work the demonstrate safety & efficacy. [1] https://en.wikipedia.org/wiki/Shinya_Yamanaka https://en.wikipedia.org/wiki/Shinya_Yamanaka [2] https://pubmed.ncbi.nlm.nih.gov/16904174/ https://pubmed.ncbi.nlm.nih.gov/16904174/

pkukp9 5y ago

Those types of stem cells can be extremely unstable and carcinogenic even, so yes, the ones that we collect are specialized specifically for either blood or tissue regeneration which is why they are more stable and not inclined to be carcinogenic.

kgin 5y ago

https://www.nature.com/articles/d41587-022-00002-4 https://www.nature.com/articles/d41587-022-00002-4 Even though nobody is quite sure how it works, it's possible to reverse the epigenetics of a cell back to its original differentiated state and even back to stem cell form not entirely unlike rolling back git commits.