Sunday, December 4, 2016
Let's examine the changes aspirin causes in the lysine acetylome!?!?
The hardest part of my Sunday morning so far has been selecting from the incredibly strange images that Google Images suggests for "aspirin side effects."
Because I have an increasingly odd sense of humor?
No! Well...partially, but also because of this new paper in press at MCP!
If I didn't make it past the introduction of this paper this would have still been worth my time, because I never had any idea how aspirin worked until this morning. In fact, I never knew that I wanted to know how aspirin worked. And if I had been asked, I would never have guessed that it would cause global level shifts in our acetylomes!
To study this, they made some heavy labeled aspirin (they tell you how to do it, even) and they treated some HeLa cells with it. Now...HeLa cells might seem like a funny pick for a pathway that we are going to extrapolate might work this way in normal biology, but with a methodology this good/interesting and well laid out, you could easily check to see if these observations reproduce in a more biologically relevant model! (Worth noting, this group is aware of the hypertriploid nature of this cell line AND used this in the standardization of the protein abundance. Which is pretty awesome!)
After dosing the cells with the heavy aspirin (and DMSO controls, of course) they digest out the peptides with LysC and do some regular proteomics. They take some of the peptides and use anti-acetylated lysine agarose beads for the enrichment steps. All the mass spec work is done on a QE Classic.
(They also throw in some SILAC time course, btw! but you'll have to read the paper for more info!)
All the downstream data processing is done with MaxQuant and they come out with some optimistic findings. While aspirin, in vitro, is going to acetylate the crap out of everything and look like its going to totally mess up all protein function -- in an in vivo model the effects don't seem nearly so destructive.
TL/DR: Great paper showing 1) how aspirin works and 2) How to do a really thorough lysine acetylomics study!