Roles of Type 10 17β-Hydroxysteroid Dehydrogenase in Health and Disease

Area of Science:

• Biochemistry
• Neuroscience
• Molecular Biology

Background:

• 17β-hydroxysteroid dehydrogenase type 10 (17β-HSD10) is encoded by the HSD17B10 gene and is involved in neurodegeneration and carcinogenesis.
• This mitochondrial protein is crucial in metabolic pathways, including amino acid degradation and neurosteroid metabolism.
• Previous controversial reports suggested 17β-HSD10 functions as Aβ-binding alcohol dehydrogenase (ABAD) or ER-associated Aβ-binding protein (ERAB).

Purpose of the Study:

• To clarify the role of 17β-HSD10 in Alzheimer's disease pathogenesis.
• To investigate the interaction between amyloid-beta (Aβ) and 17β-HSD10.
• To re-evaluate the proposed ABAD/ERAB functions of 17β-HSD10.

Main Methods:

• Analysis of kinetic parameters (Km, Ki) and experimental conditions for ABAD/ERAB assays.
• Replication of previous experimental findings.
• Comparison of Aβ's effect on 17β-HSD10 activity versus ABAD/ERAB activity.

Main Results:

• Data supporting ABAD/ERAB roles were found to be artefactual due to non-physiological conditions and unreliable estimations.
• Aβ was shown to inhibit 17β-HSD10 activity, contradicting the ABAD/ERAB hypothesis.
• Elevated 17β-HSD10 levels, alongside Aβ and phosphorylated Tau, are observed in Alzheimer's disease brains.

Conclusions:

• The ABAD/ERAB hypothesis for 17β-HSD10 is not supported by robust evidence.
• Aβ directly inhibits 17β-HSD10, suggesting a mechanism for Aβ-induced neurotoxicity.
• Understanding the role of elevated 17β-HSD10 in Alzheimer's disease is crucial for developing new therapeutic strategies.