Restoration of mitophagy ameliorates cardiomyopathy in Barth syndrome

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Barth syndrome (BTHS) is an X-linked genetic disorder caused by mutations in the TAFAZZIN/Taz gene which encodes a transacylase required for cardiolipin remodeling. Cardiolipin is a mitochondrial signature phospholipid that plays a pivotal role in maintaining mitochondrial membrane structure, respiration, mtDNA biogenesis, and mitophagy. Mutations in the TAFAZZIN gene deplete mature cardiolipin, leading to mitochondrial dysfunction, dilated cardiomyopathy, and premature death in BTHS patients. Currently, there is no effective treatment for this debilitating condition. In this study, we showed that TAFAZZIN deficiency caused hyperactivation of MTORC1 signaling and defective mitophagy, leading to accumulation of autophagic vacuoles and dysfunctional mitochondria in the heart of Tafazzin knockdown mice, a rodent model of BTHS. Consequently, treatment of TAFAZZIN knockdown mice with rapamycin, a potent inhibitor of MTORC1, not only restored mitophagy, but also mitigated mitochondrial dysfunction and dilated cardiomyopathy. Taken together, these findings identify MTORC1 as a novel therapeutic target for BTHS, suggesting that pharmacological restoration of mitophagy may provide a novel treatment for BTHS. Abbreviations: BTHS: Barth syndrome; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; CL: cardiolipin; EIF4EBP1/4E-BP1: eukaryotic translation initiation factor 4E binding protein 1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; KD: knockdown; KO: knockout; LAMP1: lysosomal-associated membrane protein 1; LV: left ventricle; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MEFs: mouse embryonic fibroblasts; MTORC1: mechanistic target of rapamycin kinase complex 1; OCR: oxygen consumption rate; PE: phosphatidylethanolamine; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PINK1: PTEN induced putative kinase 1; PRKN/Parkin: parkin RBR E3 ubiquitin protein ligase; qRT-PCR: quantitative real-time polymerase chain reaction; RPS6KB/S6K: ribosomal protein S6 kinase beta; SQSTM1/p62: sequestosome 1; TLCL: tetralinoleoyl cardiolipin; WT: wild-type.

Original languageEnglish (US)
Pages (from-to)2134-2149
Number of pages16
JournalAutophagy
Volume18
Issue number9
DOIs
StatePublished - 2022

Keywords

  • BTHS
  • MTORC1
  • TAFAZZIN
  • cardiolipin
  • mitophagy
  • rapamycin

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint

Dive into the research topics of 'Restoration of mitophagy ameliorates cardiomyopathy in Barth syndrome'. Together they form a unique fingerprint.

Cite this