Loss of ETHE1, a mitochondrial dioxygenase, causes fatal sulfide toxicity in ethylmalonic encephalopathy

verfasst von
Valeria Tiranti, Carlo Viscomi, Tatjana Hildebrandt, Ivano Di Meo, Rossana Mineri, Cecilia Tiveron, Michael D Levitt, Alessandro Prelle, Gigliola Fagiolari, Marco Rimoldi, Massimo Zeviani
Abstract

Ethylmalonic encephalopathy is an autosomal recessive, invariably fatal disorder characterized by early-onset encephalopathy, microangiopathy, chronic diarrhea, defective cytochrome c oxidase (COX) in muscle and brain, high concentrations of C4 and C5 acylcarnitines in blood and high excretion of ethylmalonic acid in urine. ETHE1, a gene encoding a β-lactamase-like, iron-coordinating metalloprotein, is mutated in ethylmalonic encephalopathy. In bacteria, ETHE1-like sequences are in the same operon of, or fused with, orthologs of TST, the gene encoding rhodanese, a sulfurtransferase. In eukaryotes, both ETHE1 and rhodanese are located within the mitochondrial matrix. We created a Ethe1-/- mouse that showed the cardinal features of ethylmalonic encephalopathy. We found that thiosulfate was excreted in massive amounts in urine of both Ethe1-/- mice and humans with ethylmalonic encephalopathy. High thiosulfate and sulfide concentrations were present in Ethe1-/- mouse tissues. Sulfide is a powerful inhibitor of COX and short-chain fatty acid oxidation, with vasoactive and vasotoxic effects that explain the microangiopathy in ethylmalonic encephalopathy patients. Sulfide is detoxified by a mitochondrial pathway that includes a sulfur dioxygenase. Sulfur dioxygenase activity was absent in Ethe1-/- mice, whereas it was markedly increased by ETHE1 overexpression in HeLa cells and Escherichia coli. Therefore, ETHE1 is a mitochondrial sulfur dioxygenase involved in catabolism of sulfide that accumulates to toxic levels in ethylmalonic encephalopathy.

Externe Organisation(en)
Istituto Nazionale Neurologico C Besta, Milan
Universitätsklinikum Düsseldorf
European Brain Research Institute Rita Levi-Montalcini (EBRI)
VA Medical Center
University of Milano-Bicocca
Typ
Artikel
Journal
Nature medicine
Band
15
Seiten
200-205
Anzahl der Seiten
6
ISSN
1078-8956
Publikationsdatum
02.2009
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Biochemie, Genetik und Molekularbiologie (insg.)
Ziele für nachhaltige Entwicklung
SDG 3 – Gute Gesundheit und Wohlergehen
Elektronische Version(en)
https://doi.org/10.1038/nm.1907 (Zugang: Unbekannt)