Alzheimer & Parkinson

No abstract

Current Aβ-targeting therapeutics for Alzheimer's disease (AD) only slow cognitive decline due to poor understanding of AD pathogenesis. Here we describe a mechanism of AD pathogenesis in which the histone methyltransferase G9a noncanonically regulates translation of hippocampal proteins associated with AD pathology. Correspondingly, we developed a brain-penetrant inhibitor of G9a, MS1262, which restored both age-related learning & memory and noncognitive functions in multiple AD mouse models....

The dopamine transporter (DAT) is linked to neuropsychiatric disorders including ADHD, Parkinson's disease, and substance use disorders. Accordingly, DAT is the target of illicit drugs and clinically important medicines. However, the number and function of ligand binding sites in DAT is enigmatic due to conflicting data from available structures and molecular pharmacology. Herein, we design force sensors with DAT ligands and measure their interaction forces with wild-type and mutated DATs, from...

Specialized intramembrane proteases, known as iCLiPs, regulate the processing of transmembrane proteins by releasing intracellular domains, which can function as transcriptional regulators. The signal peptide peptidase-like (SPPL) family of iCLiPs, particularly SPPL2b, has roles in immune regulation, neuronal function, and disease pathogenesis. In the brain, SPPL2b localizes mainly in the plasma membrane of neurons and microglia and is abundant in the cortex and hippocampus. Its known substrates...

The mitochondrial deubiquitinase ubiquitin-specific protease (USP) 30 negatively regulates PINK1-parkin-driven mitophagy. Whether enhanced mitochondrial quality control through inhibition of USP30 can protect dopaminergic neurons is currently being explored in a clinical trial for Parkinson's disease. However, the molecular basis for specific inhibition of USP30 by small molecules has remained elusive. Here we report the crystal structure of human USP30 in complex with a specific inhibitor,...

Alzheimer's disease (AD) and age-related macular degeneration (AMD) represent the leading causes of dementia and vision impairment in the elderly, respectively. The retina is an extension of the brain, yet these two central nervous system (CNS) compartments are often studied separately. Despite affecting cognition vs. vision, AD and AMD share neuroinflammatory pathways. By comparing these diseases, we can identify converging immune mechanisms and potential cross-applicable therapies. Here, we...

Self-replicating amyloid beta (Aβ) oligomers are considered as one of the major drivers for disrupted synaptic function and plasticity, leading to impaired neuronal viability and progression of Alzheimer's disease (AD). Here, we investigated the safety, tolerability and pharmacokinetics of the anti-oligomeric peptide PRI-002, which was developed to disassemble toxic Aβ oligomers into non-toxic monomers. In a randomized, double-blind, single-center phase 1b trial, 20 patients aged between 50 and...

Mitochondrial dysfunction plays a preponderant role in the development of Alzheimer disease (AD). We have demonstrated that activation of PINK1 (PTEN induced kinase 1)-dependent mitophagy ameliorates amyloid pathology, attenuates mitochondrial and synaptic dysfunction, and improves cognitive function. However, the underlying mechanisms remain largely unknown. Using a newly generated PINK1-AD transgenic mouse model and AD neuronal cell lines, we provide substantial evidence supporting the...

Parkinson's disease (PD) is a neurodegenerative disorder characterised by motor and non-motor symptoms. Recent evidence suggests a role for gut microbiome composition and diversity in PD aetiology. This study aimed to explore the association between the gut microbiome and PD in a South African population. Gut microbial sequencing data (cases: n = 16; controls: n = 42) was generated using a 16S rRNA gene (V4) primer pair. Alpha- and beta-diversity were calculated using QIIME2, and differential...

Voxel-based morphometry (VBM) and surface-based morphometry (SBM) based on magnetic resonance structural imaging were used to identify disease progression in mild cognitive impairment (MCI) patients. A retrospective analysis was conducted on 154 MCI patients from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, with 62 patients classified into the progressive MCI (pMCI) group and 92 patients into the stable MCI (sMCI) group. VBM and SBM were employed to identify structural...

Autophagy is a pro-survival process that regulates the degradation and renewal of cellular components, making it a crucial mechanism for cellular homeostasis. There are selective forms of autophagy that are specific to a number of substrates, such as pathogens (bacteria or viruses), protein aggregates or excess/damaged organelles. These processes involve as key players autophagy receptors, that link the cargo to be degraded to the autophagic machinery. Among them, NDP52 (also known as CALCOCO2)...

Alpha-synuclein (αSyn) is an intrinsically disordered protein that accumulates in the brains of patients with Parkinson's disease (PD). Through a high-throughput screen, we recently identified 38 genes whose knockdown modulates αSyn propagation. Here, we show that, among those, TAX1BP1 regulates how αSyn interacts with lipids, and ADAMTS19 modulates how αSyn phase separates into inclusions, adding to the growing body of evidence implicating those processes in PD. Through RNA sequencing, we...

The ability to transplant immunologically foreign cells into an animal without immune suppression would be transformative. Pavan et al. show that human pluripotent stem cell-derived dopaminergic neuron progenitors engineered to express eight immune-evasive proteins can engraft in humanized mice and a rat model of Parkinson's disease without recourse to immune suppression.¹.

Transplantation of human fetal ventral mesencephalic tissue in individuals with Parkinson's disease has yielded clinical benefits but also side effects, such as graft-induced dyskinesias. The open-label TransEuro trial ( NCT01898390 ) was designed to determine whether this approach could be further developed into a clinically useful treatment. Owing to poor availability of human fetal ventral mesencephalic tissue, only 11 individuals were grafted at two centers using the same tissue preparation...

Recent advances have shown that single-nucleus RNA sequencing (snRNA-seq) can be applied to formalin-fixed, paraffin-embedded (FFPE) tissues, opening avenues for transcriptomic analysis of archived specimens. Yet, isolating intact nuclei remains difficult due to RNA cross-linking. Here, we introduce a cryogenic enzymatic dissociation (CED) strategy for rapid, high-yield and fidelity nuclei extraction from FFPE samples and validate its utility with snRandom-seq (snCED-seq) using male C57/BL6...

Microglia and border-associated macrophages (BAMs) are critical for brain health, and their dysfunction is associated to disease. Replacing brain macrophages holds substantial therapeutic promise but remains challenging. Here, we demonstrate that monocytes can efficiently replace all brain macrophages. Monocytes readily replaced embryonal BAMs upon their depletion and engrafted as monocyte-derived microglia (Mo-Microglia) upon more sustained niche availability. Mo-Microglia expanded comparably...

Genetic studies implicate clusterin (CLU) in the pathogenesis of Alzheimer's disease (AD), yet its precise molecular impact remains unclear. Through unbiased proteomic profiling and functional validation in CLU-deficient astrocytes, we identify increased nuclear factor κB (NF-κB)-dependent signaling and complement C3 secretion. Reduction of astrocyte CLU induced microglia-dependent modulation of extracellular apolipoprotein E (APOE) and phosphorylated tau, as well as increased microglial...

Neurotransmitter release occurs through exocytosis of synaptic vesicles. α-Synuclein's function and dysfunction in Parkinson's disease and other synucleinopathies is thought to be tightly linked to synaptic vesicle binding. Age is the biggest risk factor for synucleinopathy, and ~15% of synaptic vesicle proteins have been linked to central nervous system diseases. Yet, age- and disease-induced changes in synaptic vesicles remain unexplored. Via systematic analysis of synaptic vesicles at the...

The differentiation of human pluripotent stem cells (hPSCs) provides access to a wide range of cell types and tissues. However, hPSC-derived lineages typically represent a fetal stage of development, and methods to expedite the transition to an aged identity to improve modeling of late-onset disease are limited. In this study, we introduce RNAge, a transcriptome-based computational platform designed to enable the evaluation of an induced aging or a rejuvenated state. We validated this approach...

In Alzheimer's disease, amyloid beta (Aβ) and tau pathology are thought to drive synapse loss. However, there is limited information on how endogenous levels of tau, Aβ and other biomarkers relate to patient characteristics, or how manipulating physiological levels of Aβ impacts synapses in living adult human brain. Using live human brain slice cultures, we report that Aβ(1-40) and tau release levels vary with donor age and brain region, respectively. Release of other biomarkers such as KLK-6,...