Dataset Information

Novel and prevalent non-East Asian ALDH2 variants; Implications for global susceptibility to aldehydes' toxicity.

ABSTRACT:

Background

Aldehyde dehydrogenase 2 (ALDH2) catalyzes the detoxification of aliphatic aldehydes, including acetaldehyde. About 45% of Han Chinese (East Asians), accounting for 8% of humans, carry a single point mutation in ALDH2*2 (E504K) that leads to accumulation of toxic reactive aldehydes.

Methods

Sequencing of a small Mexican cohort and a search in the ExAC genomic database for additional ALDH2 variants common in various ethnic groups was set to identify missense variants. These were evaluated in vitro, and in cultured cells expressing these new and common variants.

Findings

In a cohort of Hispanic donors, we identified 2 novel mutations in ALDH2. Using the ExAC genomic database, we found these identified variants and at least three other ALDH2 variants with a single point mutation among Latino, African, South Asian, and Finnish ethnic groups, at a frequency of >5/1000. Although located in different parts of the ALDH2 molecule, these common ALDH2 mutants exhibited a significant reduction in activity compared with the wild type enzyme in vitro and in 3T3 cells overexpressing each of the variants, and a greater ethanol-induced toxicity. As Alda-1, previously identified activator, did not activate some of the new mutant ALDH2 enzymes, we continued the screen and identified Alda-64, which is effective in correcting the loss of activity in most of these new and common ALDH2 variants.

Interpretation

Since ~80% of the world population consumes ethanol and since acetaldehyde accumulation contributes to a variety of diseases, the identification of additional inactivating variants of ALDH2 in different ethnic groups may help develop new 'precision medicine' for carriers of these inactive ALDH2.

SUBMITTER: Chen CH

PROVIDER: S-EPMC7218264 | biostudies-literature | 2020 May

REPOSITORIES: biostudies-literature

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Publications

Novel and prevalent non-East Asian ALDH2 variants; Implications for global susceptibility to aldehydes' toxicity.

Chen Che-Hong CH Ferreira Julio C B JCB Joshi Amit U AU Stevens Matthew C MC Li Sin-Jin SJ Hsu Jade H-M JH Maclean Rory R Ferreira Nikolas D ND Cervantes Pilar R PR Martinez Diana D DD Barrientos Fernando L FL Quintanares Gibran H R GHR Mochly-Rosen Daria D

EBioMedicine 20200508

<h4>Background</h4>Aldehyde dehydrogenase 2 (ALDH2) catalyzes the detoxification of aliphatic aldehydes, including acetaldehyde. About 45% of Han Chinese (East Asians), accounting for 8% of humans, carry a single point mutation in ALDH2*2 (E504K) that leads to accumulation of toxic reactive aldehydes.<h4>Methods</h4>Sequencing of a small Mexican cohort and a search in the ExAC genomic database for additional ALDH2 variants common in various ethnic groups was set to identify missense variants. Th ...[more]

PMID: 32403082

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Project description:Obesity and type 2 diabetes have reached pandemic proportion. In particular, the population with diabetes is expected to rise rapidly in East and South Asia. ALDH2 (acetaldehyde dehydrogenase 2, mitochondrial) is the key metabolizing enzyme of acetaldehyde and other toxic aldehydes, such as 4-hydroxynonenal (4-HNE). A missense Glu504Lys mutation of the ALDH2 gene is prevalent in 560 million East Asians, resulting in reduced ALDH2 enzymatic activity. We found that Aldh2 knock-in (KI) mice mimicking human Glu504Lys mutation were prone to develop diet-induced obesity, glucose intolerance, insulin resistance, and fatty liver compared with controls due to reduced adaptive thermogenesis and energy expenditure. We found elevated 4-HNE levels and increased 4-HNE adducted proteins due to reduced activity of ALDH2 of the brown adipose tissue (BAT) from the Aldh2 homozygous KI mice. Proteomic analyses of the BAT from the Aldh2 KI mice identified increased 4-HNE-adducted proteins involved in mitochondrial fatty acid oxidation (FAO) and electron transport chain (ETC), leading to markedly decreased FAO and mitochondrial respiration of BAT, which is essential for adaptive thermogenesis and energy expenditure. AD-9308 is a water-soluble prodrug of a potent and highly selective ALDH2 activator AD-5591. In vitro, AD-5591 enhanced both WT and mutant ALDH2 enzymatic activities. AD-9308 allosterically activates ALDH2 mainly by partially blocking the substrate exit tunnel, thereby accelerating the substrate-enzyme collision.4-HNE-adducted proteins, especially those involved in mitochondrial fatty acid beta-oxidation and electron transfer chain of the brown adipose tissue from the Aldh2 knock-in mice, leading to impaired mitochondrial dysfunction brown adipose tissue. In vivo, AD-9308 treatment reduced serum 4-HNE levels, ameliorated diet-induced obesity and fatty liver, and improved glucose homeostasis in both Aldh2 WT and KI mice dose-dependently. Our data highlight the therapeutic potential of reducing toxic aldehyde levels by activating ALDH2 for treating metabolic diseases.

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Dataset Information

Novel and prevalent non-East Asian ALDH2 variants; Implications for global susceptibility to aldehydes' toxicity.

Background

Methods

Findings

Interpretation

Publications

Novel and prevalent non-East Asian ALDH2 variants; Implications for global susceptibility to aldehydes' toxicity.

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