发信人: netbuggie (中原一点虫), 信区: Biology
标 题: Re: 略感失望
发信站: The unknown SPACE (Mon May 28 22:01:01 2001), 站内信件

the essential part of the paper is that it explores the possibility
to manuipulate ES cell differentiation in vitro, which could elicit
clinical usage, but also ethical controversial as well. technically,
they have been lucky and smart enough to generate/reconstitute
a population of pancreatic islet-like ES cell lines that can respond
to glucose in vitro experiments. according to their hypothesis of
similarity between CNS and pancreas during development, it is not
quite suprising to use the neuron marker nestin for selection. it is
sth difficult to culture ES cells in medium, and it is even more
difficult to control and enrich the differentiated cell types that
they want. i would not say the in vivo sc. transplantation result
is disappointed, since it could be due to immunoreactivity, dosage
effect, etc. and also cell-cell contact/communications have been shown
to be critical to establish the proper function of pancreas, which
could be problematic in this experiment. ppl have found that beta-cells
tend to form pseudoislet, which can still have glucose-stimulating
insulin secretion. thus, it is not surprising to see that their ES cells
have similar function. however, previous, there is another one "glucose
dependent insulin release from genetically engineered K cells" on Science,
290:1959. it is a tumor-derived K-cell ( stomach cell line ). Transgenice
mice expressed human insulin specifically in gut K cells in a feeding
dependent style. this work seems to be more productive than the ES cell
work. but the later could be more useful for other purpose as well *_*.

【 在 bioyy (豌豆园里的长工) 的大作中提到: 】
: Defferentiation of embryonic stem cells to insulin-secreting
: structures similar to pancreatic islets
: Science 292 18 May 2001
: ES cells were coaxed to secret insulin, the in vitro data
: looks
: very good, but the in vivo part is a kind of dissapointed.
: In terms of transplantation and function in vivo, is the
: following points going to be important?
: 1. immune rejection (even for ES cells)
: 2. ways of transplant (s.c. vs others?)
: 3. physiological regulation by nervous system?
: Wellcome for discussion.


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