A small-molecule DS44170716 inhibits Ca2+-induced mitochondrial permeability transition

• Main Authors: Naohiro Kon, Atsushi Satoh, Naoki Miyoshi
• Format: Article
• Language: English
• Published: Nature Publishing Group 2017-06-01
• Series: Scientific Reports
• Online Access: https://doi.org/10.1038/s41598-017-03651-7

Abstract Mitochondria are involved in a variety of physiological and pathological processes. Ca2+ uptake is one of the important functions of the organelle for maintenance of cellular Ca2+ homeostasis. In pathological conditions such as ischemia reperfusion injury, Ca2+ overload into mitochondria induces mitochondrial permeability transition (MPT), a critical step for cell death. Because inhibition of MPT is a promising approach to protecting cells and organs, it is important for drug discovery to identify novel chemicals or mechanisms to inhibit MPT. Here we report upon a small-molecule compound DS44170716 that inhibits Ca2+-induced MPT in rat liver isolated mitochondria. DS44170716 protects human liver HepG2 cells from Ca2+-induced death with a level of protection similar to cyclosporin A (CsA). The inhibitory mechanism of DS44170716 against MPT is independent on PPIF, a target of CsA. DS44170716 blocks Ca2+ flux into the mitochondria by decreasing mitochondrial membrane potential, while potently inhibiting mitochondrial complex III activities and weakly inhibiting complex IV and V activities. Similarly, complex III inhibitor antimycin A, complex IV inhibitor KCN or complex V inhibitor oligomycin inhibits Ca2+ uptake of isolated mitochondria. These results show that DS44170716 is a novel class inhibitor of MPT by blocking of mitochondrial complexes and Ca2+-overload into mitochondria.