mTORC1 inhibition attenuates necroptosis through RIP1 inhibition-mediated TFEB activation

Publication date: Available online 6 September 2019Source: Biochimica et Biophysica Acta (BBA) - Molecular Basis of DiseaseAuthor(s): Koki Abe, Toshiyuki Yano, Masaya Tanno, Takayuki Miki, Atsushi Kuno, Tatsuya Sato, Hidemichi Kouzu, Kei Nakata, Wataru Ohwada, Yukishige Kimura, Hirohito Sugawara, Satoru Shibata, Yusuke Igaki, Shoya Ino, Tetsuji MiuraAbstractAccumulating evidence indicates that necroptosis contributes to cardiovascular diseases. We recently reported suppression of autophagy by necroptotic signals in cardiomyocytes and protective action of rapamycin. Here we examined the mechanism by which mTORC1 inhibition protects cardiomyocytes from necroptosis. Necroptosis of H9c2 cells was induced by treatment with tumor necrotic factor-α (TNF) and z-VAD-fmk (zVAD), and the extent of necroptosis was determined as the level of LDH release (as % of total). TNF/zVAD increased RIP1-RIP3 interaction and LDH release from 3.4 ± 1.3% to 46.1 ± 2.3%. The effects of TNF/zVAD were suppressed by an mTORC1 inhibitor, rapamycin, and an mTORC1/2 inhibitor, Ku-0063794, but not by a p70S6K inhibitor, PF-4708671. Protection by rapamycin was not abolished by inhibitors of TAK1, IKKα/β, and cIAP, endogenous necroptosis suppressors upstream of RIP1. Rapamycin and Ku-0063794 suppressed TNF/zVAD-induced RIP1-Ser166 phosphorylation and increased phosphorylation of RIP1-Ser320, an inhibitory phosphorylation site, though such an effect on RIP1-Ser320 was not observed for PF-4708671. Pr...
Source: Biochimica et Biophysica Acta (BBA) Molecular Basis of Disease - Category: Molecular Biology Source Type: research