sodium butyrate on 293's - (Aug/09/2006 )
it's described that sodium butyrate at various concentrations ranging from 4mM to about 10mM can increase expression from viral LTR-promotors. I've transfected 293T's yesterday, and have added sodium butyrate at various concentrations in severall dishes. I think I see an increase in expression of my fluorescent protein reporter (DsRed2, included in a complete HIV-virus, therefor it is only expressed when non-spliced RNA's are transcribed, the non-spliced RNA's get to the cytoplasm due to the activity of another HIV-protein) on my plates with sodium butyrate.
I will later on check the concentration in of HIV p24 antigen in supernatans (which will be a lot more precise of course than my visual inspection).
But my question is: how long can 293 cells survive sodium buturate in supernatans? Some remove it after 8 hours, whereas others don't mention removing it from their cells...
Does anyone have any clue about it?
Sodium butyrate is definitely toxic for the cells, but u also get good virus production. Some papers suggested having it for the first 24hrs. When I tried the same I got many dead cells but the virus titres were as good as when I combine my 24 and 48 hr fractions. What bothered me was the effect the dead cells might release which could later interfere with experiments.
let us know which conc. worked good for u.
I don't know oabout HEK293 or virus titres but I know about Sodium Butyrate.
It's a non-specific Histone Deacetylase (HDAC) Inhibitor which acts as a cellular differentiating agent. It can also cause the upregulation of certain genes at the level of promoter activity. Anywhere between 2-5 mM is sufficient for this and 24 hrs would be more than adequate.
I'm not sure at what levels it is toxic or even if it really is. Butyrate levels can reach 20 mM in the lumen of the human gut and it causes epithelial cell differentation and development.
It is also responsible for the smell of the vomit when you puke. But if you use NaB you'll know that already from [unpleasant] experience.
I used 4mM and it nearly killed most of my cells. I asked around abt using sodium butyrate and they suggested that it is toxic for cells. People and literature vary abt the conc. which is toxic for cells.
I guess it depends on the cell type. You puke up more than 4 mM.