HMGCS2-Induced Autophagic Degradation of Tau Involves Ketone Body and ANKRD24.

Background: Accumulation of hyperphosphorylated Tau (pTau) contributes to the formation of neurofibrillary tangles in Alzheimer's disease (AD), and targeting Tau/pTau metabolism has emerged as a therapeutic approach. We have previously reported that mitochondrial 3-hydroxy-3-methylglutaryl-COA synthase 2 (HMGCS2) is involved in AD by promoting autophagic clearance of amyloid-β protein precursor via ketone body-associated mechanism, whether HMGCS2 may also regulate Tau metabolism remains elusive.

Objective: The present study was to investigate the role of HMGCS2 in Tau/p degradation.

Sulfuretin exerts diversified functions in the processing of amyloid precursor protein.

Sulfuretin is a flavonoid that protects cell from damage induced by reactive oxygen species and inflammation. In this study, we investigated the role of sulfuretin in the processing of amyloid precursor protein (APP), in association with the two catalytic enzymes the α-secretase a disintegrin and metalloproteinase (ADAM10), and the beta-site APP cleaving enzyme 1 (BACE1) that play important roles in the generation of β amyloid protein (Aβ) in Alzheimer's disease (AD). We found that sulfuretin increased the levels of the immature but not the mature form of ADAM10 protein.

TUFM is involved in Alzheimer's disease-like pathologies that are associated with ROS.

Mitochondrial Tu translation elongation factor (TUFM or EF-Tu) is part of the mitochondrial translation machinery. It is reported that TUFM expression is reduced in the brain of Alzheimer's disease (AD), suggesting that TUFM might play a role in the pathophysiology. In this study, we found that TUFM protein level was decreased in the hippocampus and cortex especially in the aged APP/PS1 mice, an animal model of AD.

Mitochondrial TXN2 attenuates amyloidogenesis via selective inhibition of BACE1 expression.

Thioredoxin-2 (TXN2) is a mitochondrial protein and represents one of the intrinsic antioxidant enzymes. It has long been recognized that mitochondrial dysfunction and oxidative stress contribute to the pathogenesis of Alzheimer's disease (AD). We hypothesized that mitochondrial TXN2 might play a role in AD-like pathology.

HMGCS2 promotes autophagic degradation of the amyloid-β precursor protein through ketone body-mediated mechanisms.

HMGCS2 (mitochondrial 3-hydroxy-3-methylglutaryl-COA synthase 2) is a control enzyme in ketogenesis. The mitochondrial localization and interaction with APP (β-amyloid precursor protein) suggest that HMGCS2 may play a role in the pathophysiology of AD (Alzheimer's disease). Here we report that overexpression of HMGCS2 decreased levels of APP and related CTFs (carboxy-terminal fragments), which was largely prevented by an autophagic inhibitor chloroquine.