Iron chelator desferrioxamine induces decrease of mitochondrial heat shock protein TNF receptor‐associated protein 1(TRAP1) in Chang cells

Abstract

Heat shock proteins (HSPs) are molecular chaperones which regulate diverse cellular functions e.g. apoptosis and cell cycle. Tumour necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial HSP and has been reported that it may play roles in apoptosis as well as differentiation. But the exact roles of TRAP1 remain unclear. It has been implicated that iron chelator desferroxamine (DFO) induces mitochondrial dysfunction such as decrease of oxidative phosphorylation as well as change of cellular morphology. We used DFO to examine the mitochondrial morphology, function, and levels of related mitochondrial HSPs. Treatment of DFO increased transferrin mRNA but not aconitase1 and transferrin receptor1 in human hepatocyte cell line Chang cells. In addition, DFO induced G0/G1 cell cycle arrest, abnormal morphology of mitochondria, decrease of NADH-dependent dehydrogenase activity, and disruption of mitochondrial membrane potential (ΔΨm). Also we found decrease of TRAP1 at the mRNA and protein level in DFO-treated Chang cells, but not other mitochondrial HSPs such as HSP60, mtHSP70. This result suggests that TRAP1 might have an important role to maintain mitochondrial integrity.