Xanthurenic acid translocates proapoptotic Bcl-2 family proteins into mitochondria and impairs mitochondrial function.
BACKGROUND
Xanthurenic acid is an endogenous molecule produced by tryptophan degradation, produced in the cytoplasm and mitochondria. Its accumulation can be observed in aging-related diseases, e.g. senile cataract and infectious disease. We previously reported that xanthurenic acid provokes apoptosis, and now present a study of the response of mitochondria to xanthurenic acid.


RESULTS
Xanthurenic acid at 10 or 20 microM in culture media of human aortic smooth muscle cells induces translocation of the proteins Bax, Bak, Bclxs, and Bad into mitochondria. In 20 microM xanthurenic acid, Bax is also translocated to the nucleus. In isolated mitochondria xanthurenic acid leads to Bax and Bclxs oligomerization, accumulation of Ca2+, and increased oxygen consumption.


CONCLUSIONS
Xanthurenic acid interacts directly with Bcl-2 family proteins, inducing mitochondrial pathways of apoptosis and impairing mitochondrial functions.
Malina
Halina Z
HZ
Xanthurenic Acid Laboratory, Department Cardiology, Inselspital, CH-3010 Bern, Switzerland. hmalina@hotmail.com
Hess
Otto M
OM
D017209:Apoptosis; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D008928:Mitochondria / Q000378:metabolism* / Q000502:physiology; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010101:Oxygen Consumption; D021381:Protein Transport; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D014977:Xanthurenates / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein
C494826:BAX protein, human; C494811:BCL2L1 protein, human; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D014977:Xanthurenates; D051028:bcl-2-Associated X Protein; D051020:bcl-X Protein; C028330:xanthurenic acid; D002118:Calcium