Analysis of transition state mimicry by tight binding aminothiazoline inhibitors provides insight into catalysis by human O-GlcNAcase

The modification of nucleocytoplasmic proteins with O-linked N-acetylglucosamine (O-GlcNAc) plays diverse roles in multicellular organisms. Inhibitors of O-GlcNAc hydrolase (OGA), the enzyme that removes O-GlcNAc from proteins, lead to increased O-GlcNAc levels in cells and are seeing widespread adoption in the field as a research tool used in cells and in vivo. Here we synthesize [...]

February 15th, 2016|Tags: , , |

Alectos Announces Preclinical Results in TAPP Mouse Model of Alzheimer’s Disease

Oct 26, 2014 – Alectos today announced publication of preclinical studies showing that pharmacological inhibition of O-GlcNAcase (OGA) prevents cognitive decline and amyloid plaque formation in the TAPP mouse model of Alzheimer’s disease. For details, see: Yuzwa, S.A. et al. Mol Neurodegener 9:42 (2014).

October 26th, 2014|Tags: , , , , , , , |

Pharmacological inhibition of O-GlcNAcase (OGA) prevents cognitive decline and amyloid plaque formation in bigenic tau/APP mutant mice

BACKGROUND: Amyloid plaques and neurofibrillary tangles (NFTs) are the defining pathological hallmarks of Alzheimer's disease (AD). Increasing the quantity of the O-linked N-acetylglucosamine (O-GlcNAc) post-translational modification of nuclear and cytoplasmic proteins slows neurodegeneration and blocks the formation of NFTs in a tauopathy mouse model. It remains unknown, however, if O-GlcNAc can influence the formation of [...]

October 26th, 2014|Tags: , , , , , , , |

The emerging link between O-GlcNAc and Alzheimer disease

Regional glucose hypometabolism is a defining feature of Alzheimer disease (AD). One emerging link between glucose hypometabolism and progression of AD is the nutrient-responsive post-translational O-GlcNAcylation of nucleocytoplasmic proteins. O-GlcNAc is abundant in neurons and occurs on both tau and amyloid precursor protein. Increased brain O-GlcNAcylation protects against tau and amyloid-β peptide toxicity. Decreased O-GlcNAcylation [...]

October 21st, 2014|Tags: , , , , , , , , , , |

Chronic O-β-N-acetylglucosaminylase inhibition with Thiamet-G prevents tau pathology and hyperactivity in rTg4510 mice

Background: The abnormal hyperphosphorylation of the microtubule-associated protein tau plays a crucial role in neurodegeneration in Alzheimer's disease (AD) and aggregation of hyperphosphorylated tau into neurofibrillary tangles is a hallmark brain lesion in AD. Besides kinases and phosphatases tau phosphorylation is regulated by O-GlcNAcylation, a posttranslational modification of proteins on the serine or threonine residues with [...]

September 6th, 2014|Tags: , , , , , |

O-GlcNAc and neurodegeneration: biochemical mechanisms and potential roles in Alzheimer’s disease and beyond

Alzheimer disease (AD) is a growing problem for aging populations worldwide. Despite significant efforts, no therapeutics are available that stop or slow progression of AD, which has driven interest in the basic causes of AD and the search for new therapeutic strategies. Longitudinal studies have clarified that defects in glucose metabolism occur in patients exhibiting [...]

April 24th, 2014|Tags: , , , , , , , , |

Increasing brain protein O-GlcNAcylation mitigates breathing defects and mortality of Tau.P301L mice

The microtubule associated protein tau causes primary and secondary tauopathies by unknown molecular mechanisms. Post-translational O-GlcNAc-ylation of brain proteins was demonstrated here to be beneficial for Tau.P301L mice by pharmacological inhibition of O-GlcNAc-ase. Chronic treatment of ageing Tau.P301L mice mitigated their loss in body-weight and improved their motor deficits, while the survival was 3-fold higher [...]

December 23rd, 2013|Tags: , , , , |

Increased O-GlcNAcylation reduces pathological tau without affecting its normal phosphorylation in a mouse model of tauopathy

Neurofibrillary tangles (NFT), mainly consisting of fibrillar aggregates of hyperphosphorylated tau, are a defining pathological feature of Alzheimer's Disease and other tauopathies. Progressive accumulation of tau into NFT is considered to be a toxic cellular event causing neurodegeneration. Tau is subject to O-linked N-acetylglucosamine (O-GlcNAc) modification and O-GlcNAcylation of tau has been suggested to regulate [...]

December 8th, 2013|Tags: , , , , , |

Increasing O-GlcNAc slows neurodegeneration and stabilizes tau against aggregation

Oligomerization of tau is a key process contributing to the progressive death of neurons in Alzheimer’s disease. Tau is modified by O-linked N-acetylglucosamine (O-GlcNAc), and O-GlcNAc can influence tau phosphorylation in certain cases. We therefore speculated that increasing tau O-GlcNAc could be a strategy to hinder pathological tau-induced neurodegeneration. Here we found that treatment of [...]

February 26th, 2012|Tags: , , , , , |

A potent mechanism-inspired O-GlcNAcase inhibitor that blocks phosphorylation of tau in vivo

Pathological hyperphosphorylation of the microtubule-associated protein tau is characteristic of Alzheimer’s disease (AD) and the associated tauopathies. The reciprocal relationship between phosphorylation and O-GlcNAc modification of tau and reductions in O-GlcNAc levels on tau in AD brain offers motivation for the generation of potent and selective inhibitors that can effectively enhance O-GlcNAc in vertebrate brain. [...]

June 29th, 2008|Tags: , , , , |