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HSCs are responsible for keeping us alive by granting us an eternal supply of blood cells.  (Source: Microscopy Inc.)

Rice University bioengineers Oleg Igoshin (left) and Jatin Narula may have found the switch that tells HSCs when to differentiate and self renew.  (Source: Jeff Fitlow/Rice University)
Master regulator could allow for easy growth direction, organ creation

Scientists are racing towards a future vision in which humans can regrow failing organs and essentially obtain immortality.  Along the way, they're shooting for the more obtainable aim of curing a number of diseases (cancer, Alzheimer's, Parkinson's, and paralysis, to list but a few) using stem cells.

A critical problem though is how to direct stem cells to become the proper tissue type.  Within the human body, there are a rich variety of cells -- endothelial cells, muscle cells, blood cells, osteoblasts (bone), and nerve cells to name but a few.  At some point in the development of the human body, these cell lines were created by a biochemical signal which instructing stem cells to become the particular cell type.

Experimentalists at Cambridge University and Rice bioengineers Oleg Igoshin and Jatin Narula have examined one of these critical biochemical signals.  Based on a computer model developed at Rice and experiments at Cambridge, they believe that a trio of regulatory proteins known as the "Scl-Gata2-Fli1 triad" controls the differentiation of hematopoietic stem cells (HSCs), the self-renewing cells the body uses to make new blood cells.

In healthy adult humans, each day HSCs are responsible for the creation of 100 billion new white and red blood cells.  HSCs are also capable of "self-renewing" if the bone marrow is damaged.

The research at Rice delved into looking at the three regulatory proteins and developing an mathematical model for how they interacted with HSCs.  In their model, the proteins act as a bistable switch, with two states -- "replenish HSC" and "differentiate".  The system ignores extraneous signals and throws the switch only when a signal persisted.

Igoshin, an assistant professor in bioengineering at Rice, comments, "We don't yet have the experimental verification that this is the master-level regulator for HSCs, but based on our model, we can say that it has all the properties that we would expect to find in a master-level regulator."

Jatin Narula, a Rice graduate student, adds, "In examining the results from the model, we found the triad did have the characteristics of a master regulator.  The first time it's switched on, all the cells stay on. It also handles deactivation in a controlled manner, so that some cells differentiate and get deactivated and others don't. Finally, it has the ability to discern whether or not the level of signal is present only for a short burst or for a significantly long time."

Rice researchers hope that the regulatory triad motif reappears in other types of stem cells, possibly leading to more breakthroughs.

The results of the study are published in the journal 
PLoS Computational Biology.



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By eskimospy on 5/8/2010 11:45:03 AM , Rating: 1
Shockingly enough, liberals are not cartoon super villains bent on killing as many babies as possible. If you truly believe what you wrote, you are incapable of looking at this issue rationally as you are blinded by ideology.

The boring and old abortion debate on whether or not an embryo constitutes life or not aside, the argument you present is a false choice. It's not adult vs. embryonic, it's adult vs. adult and embryonic stem cell research combined.

If there end up being no effective treatments to be had through embryonic stem cell research, the funding and the research will dry up on its own, no ban needed. Conservatives aren't trying to ban it based upon the merits of the science though, they are trying to ban it based upon their personal morality. While everyone would likely agree that science should be subject to the limits of morality in some cases, this opposition is by definition anti-science.

Maybe embryonic stem cells will be an abject failure, but if we are presented with a problem and someone tells you 'the solution to this problem is under either box A (adult stem cells) or box B (embryonic stem cells), a smart and rational person looks under both boxes . This is why in poll after poll (depending on methodology) the public support for embryonic stem cell research is anywhere from the mid 50% range all the way up to about 75%. To the best of my knowledge is has NEVER been exceeded by those against embryonic stem cell research.


RE: In silico biology does not equal real biology
By ekv on 5/8/2010 9:14:02 PM , Rating: 2
I think you are blinded by your ideology. The ban on embryonic stem cell research was a ban on federally funded research. Private companies can and did fund embryonic stem cell research. So far, no breakthoughs have been found. I might add, nor are likely to be found, since articles have been published pointing out the instability of embryonic stem cells.

You seem to be going through extreme contortions in order to argue your case. Based on a false premise, you are only going to come up with a false conclusion.

Having certain morals guide your progress does not mean you are "anti-science", but rather that you are indeed a plateau above the animals. Do you have trouble being differentiated from the animals?


By eskimospy on 5/9/2010 6:43:54 PM , Rating: 2
By all means let me know what 'extreme contortions' you think I am going through, along with the 'false premise' that you believe my reply was based upon.

Methinks you are projecting some, big guy. :)


RE: In silico biology does not equal real biology
By ekv on 5/10/2010 1:08:51 AM , Rating: 2
I guess I don't understand. It's rather plain English. Perhaps you're incapable of doing an Internet search? or are you just lazy? Try "Stem Cell Controversy"

Even a liberal web-site says
quote:
The current Congressional ban on federal funding for human embryo research allows stem cell researchers to work with only existing stem cell lines.
That was 2006. Obama has undone this, just for the sake of undoing it I'd wager, the typical liberal knee-jerk reaction. How naive can you get.


RE: In silico biology does not equal real biology
By eskimospy on 5/10/2010 9:27:23 AM , Rating: 2
Yeap, that's what I thought.

Bush's funding for 19 lines was woefully inadequate and anyone who has spent more than 5 minutes reading about this subject knows it.

Furthermore, since my post wasn't based upon Bush's policies but instead the merits of an open approach that conservatives generally oppose, the fact that you thought you were undercutting me by posting it shows how poorly you understood what you read.

I can already tell you're just here to fight,not to actually discuss it. Grow up.


By ekv on 5/11/2010 12:36:50 PM , Rating: 2
Excuse me? What are you thinking?!

Bush's funding ought to have been zero. I have moral reservations about Federal funding of a questionable scientific endeavor / fishing-expedition. I'll say it again, private companies can and did continue their research. It's their money and, while we're less free than a couple years ago, it's still a free country.

Yes, I'm here to fight. What was your first clue?


"Nowadays, security guys break the Mac every single day. Every single day, they come out with a total exploit, your machine can be taken over totally. I dare anybody to do that once a month on the Windows machine." -- Bill Gates














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