Down syndrome is an oxidative phosphorylation disorder

Abstract

Down syndrome is the most common genomic disorder of intellectual disability and is caused by trisomy of chromosome 21. Several genes in this chromosome repress mitochondrial biogenesis. The goal of this study was to evaluate whether early overexpression of these genes may cause a prenatal impairment of oxidative phosphorylation negatively affecting neurogenesis. Reduction in the mitochondrial energy production and a lower mitochondrial function have been reported in diverse tissues or cell types, and also at any age, including early fetuses, suggesting that a defect in oxidative phosphorylation is an early and general event in Down syndrome individuals. Moreover, many of the medical conditions associated with Down syndrome are also frequently found in patients with oxidative phosphorylation disease. Several drugs that enhance mitochondrial biogenesis are nowadays available and some of them have been already tested in mouse models of Down syndrome restoring neurogenesis and cognitive defects. Because neurogenesis relies on a correct mitochondrial function and critical periods of brain development occur mainly in the prenatal and early neonatal stages, therapeutic approaches intended to improve oxidative phosphorylation should be provided in these periods.

Graphical abstract

Highlights

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  Several chromosome 21-encoded proteins repress mitochondrial biogenesis.

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  These proteins are overexpressed in fetal brains of Down syndrome (DS) individuals.

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  Oxidative phosphorylation function is essential for neurogenesis.

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  Upregulation of these proteins adversely impact on neurogenesis.

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  Prenatal therapy with drugs inhibiting these proteins would increase DS neurogenesis.