5 ms·

I want to say, maybe it's better to say first human under proper IRB/regulatory compliance. Some rogue academic in China tried it a few years ago, if I recall

by caycep 1y ago

I want to say, maybe it's better to say first human under proper IRB/regulatory compliance. Some rogue academic in China tried it a few years ago, if I recall, but with absolutely no oversight and he was pilloried. Also I don't think there is much details about what he actually did... https://www.npr.org/2023/06/08/1178695152/china-scientist-he-jiankui-crispr-baby-gene-editing https://www.npr.org/2023/06/08/1178695152/china-scientist-he...

dekhn 1y ago
What the Chinese guy (He) did was completely different. He permanently altered the germline in embryos, which means that every cell in the resulting baby is transformed permanently with the change he made. The work he did violated a wide range of good practice (specifically, the change he made didn't actually work for the goal he desired, and he also ignored all the ethical advice around this experiment, and avoided getting the necessary approvals). This research is instead a therapy used to treat an already born baby, and it doesn't modify all the cells in the body. Many cells in the body that are transformed by this technique will eventually die and be replaced by clones of stem cells which weren't transformed. I haven't read in detail about whether this therapy targets stem cells, and how long term effective the treatment will be- hepatocytes (liver cells) turn over constantly, so I would expect if the treatment did not affect the hepatocyte stem cells, it would only last ~months and the treatment would have to be repeated.
- SubiculumCode 1y ago
  Do new liver cells always come from stem cells, not from dividing liver cells? Are those heppatocyte stem cells reside in the liver, or do they travel their via migration,.or blood, etc? A quick search suggests that liver regen involves dividing mature liver cells to replace turnover. If so, I'd suspect that they'd continue to carry the.crispr edit forward.
  - dekhn 1y ago
    I believe new liver cells come from both dividing mature hepatocytes, and hepatocyte stem cells. Cells can only divide a limited number of times, and they can't easily re-differentiate, so I would expect that while dividing mature hepatocytes would propagate the edit, they would eventually be replaced by cells that derived from stem cells that didn't get the edit.
zardo 1y ago
The major difference is that was a hereditary change. So those changes could now diffuse throughout the species over time. As I recall it was a change that reduces vulnerability to HIV infection.

by caycep 1y ago

dekhn 1y ago

What the Chinese guy (He) did was completely different. He permanently altered the germline in embryos, which means that every cell in the resulting baby is transformed permanently with the change he made. The work he did violated a wide range of good practice (specifically, the change he made didn't actually work for the goal he desired, and he also ignored all the ethical advice around this experiment, and avoided getting the necessary approvals). This research is instead a therapy used to treat an already born baby, and it doesn't modify all the cells in the body. Many cells in the body that are transformed by this technique will eventually die and be replaced by clones of stem cells which weren't transformed. I haven't read in detail about whether this therapy targets stem cells, and how long term effective the treatment will be- hepatocytes (liver cells) turn over constantly, so I would expect if the treatment did not affect the hepatocyte stem cells, it would only last ~months and the treatment would have to be repeated.

SubiculumCode 1y ago
Do new liver cells always come from stem cells, not from dividing liver cells? Are those heppatocyte stem cells reside in the liver, or do they travel their via migration,.or blood, etc? A quick search suggests that liver regen involves dividing mature liver cells to replace turnover. If so, I'd suspect that they'd continue to carry the.crispr edit forward.
- dekhn 1y ago
  I believe new liver cells come from both dividing mature hepatocytes, and hepatocyte stem cells. Cells can only divide a limited number of times, and they can't easily re-differentiate, so I would expect that while dividing mature hepatocytes would propagate the edit, they would eventually be replaced by cells that derived from stem cells that didn't get the edit.

zardo 1y ago

The major difference is that was a hereditary change. So those changes could now diffuse throughout the species over time. As I recall it was a change that reduces vulnerability to HIV infection.