Hi,

I study lipid metabolism in Leishmania parasites. For this I have generated mutant parasites that are defective in sterol biosynthesis. Recently while characterizing these mutant parasites, I got an interesting data. Initially I found that my sterol mutants have high mitochondrial membrane potential than that of the wild type parasites, which is an indicative of more active mitochondria. Since, higher mitochondrial activity may lead to increased superoxide production which in turn can cause oxidative damage to the cells, I measured the mitochondrial superoxide production by MitoSox reagent. My data show that the mitochondria in the mutants accumulate much higher superoxides than the WT.

Further I wanted to check the hydrogen peroxide content of the mitochondria and for this I stained the parasites with H2DCFDA from Thermo Sc. Interestingly, the mutants show much less accumulation of hydrogen peroxide than the WT. In the mean time I also analyzed the superoxide dismutase level from total cell lysates. Here I found that the mutants had slightly higher activity than the WT.

My question is:

How could I correlate the higher superoxide aaccumulation with less hydrogen peroxide production in the mitochondria of mutant parasites?

I would greatly appreciate any comment on this!

Thanks

Sumit