Cellular redox regulation has been described to be influenced in ETHE1 deficient cells, and to clarify this further we applied image cytometry and detected decreased levels of reduced glutathione (GSH) in cultivated EE patient fibroblast cells.
Ethylmalonic encephalopathy (EE) is a rapidly progressive autosomal recessive mitochondrial disease caused by biallelic pathogenic variants in the ETHE1 gene that encodes the mitochondrial sulfur dioxygenase.
Ethylmalonic encephalopathy (EE) is a devastating neurodegenerative disease caused by mutations in the ETHE1 gene critical for hydrogen sulfide (H<sub>2</sub>S) detoxification.
Defects in the gene encoding the persulfide dioxygenase ETHE1 are known to cause the severe inherited metabolic disorder ethylmalonic encephalopathy (EE).
Mutations to the hETHE1 gene compromise sulfide metabolism leading to the genetic disease ethylmalonic encephalopathy. hETHE1 is a mono-iron binding member of the metallo-β-lactamase (MBL) fold superfamily.
Here, we will review two peculiar mitochondrial disorders, ethylmalonic encephalopathy (EE) and mitochondrial neurogastrointestinal encephalomyopathy (MNGIE), caused by mutations in the ETHE1 and TYMP nuclear genes, respectively.
To address this issue and to elicit how ETHE1 dysfunction results in EE, we have investigated two such pathological mutations, ETHE1-p.Arg163Gln and p.Arg163Trp.
By studying a suitable mouse model, we found that loss of ETHE1 leads to accumulation of sulphide, which is a poison for COX and other enzymatic activities thus accounting for the main features of EE.
Here, we show that AAV2/8-mediated, ETHE1-gene transfer to the liver of a genetically, metabolically and clinically faithful EE mouse model resulted in full restoration of SDO activity, correction of plasma thiosulfate, a biomarker reflecting the accumulation of H(2)S, and spectacular clinical improvement.
Ethylmalonic encephalopathy (EE) is a rare autosomal recessive disorder caused by mutations in the ETHE1 gene and characterized by chronic diarrhea, encephalopathy, relapsing petechiae and acrocyanosis.
Tissue-specific ablation of Ethe1 causes COX deficiency in targeted organs, suggesting that failure in neutralizing endogenous, tissue-specific production of H(2)S is sufficient to cause the biochemical defect but neither to determine a clinical impact nor to induce the biomarker profile typical of EE.
Ethylmalonic encephalopathy is caused by mutations in ETHE1, a mitochondrial matrix sulfur dioxygenase, leading to failure to detoxify sulfide, a product of intestinal anaerobes and, in trace amounts, tissues.