Alzheimer & Parkinson

APOE4 is the leading genetic risk factor for Alzheimer's disease, and chronic stress is a leading environmental risk factor. Studies suggest that APOE4 confers vulnerability to the behavioral and neuropathological effects of chronic stress, representing a potential mechanism by which this genetic variant accelerates Alzheimer's onset and progression. Whether and how APOE4-mediated stress vulnerability manifests in neurons of the hippocampus, a brain region particularly susceptible to stress and...

The G-protein-coupled receptor kinase 2 (GRK2) exerts essential functions in cell growth and survival. Searching for a connection between GRK2 and the neurodegenerative Alzheimer disease (AD), we find increased aggregated serine-670-phosphorylated GRK2 (phospho-S670-GRK2) in brains of AD mice and patients with dementia likely due to AD. Harmful phospho-S670-GRK2 aggregation is induced by two hallmark proteins of AD: beta-amyloid and the neurofibrillary-tangle-inducing, TAU-P301L. Aggregated...

Sex and apolipoprotein E ε4 (APOE4) interact to alter the risk for Alzheimer's disease and other neurodegenerative disorders. Herein, we show sex-specific differences in immune activation and lymphatic function in the meningeal dura of humanized female and male mice expressing two alleles of APOE4 (E4/E4), when compared with their respective sex-matched E3/E3 controls. We also describe distinct effects of APOE4 on brain lipid composition and inflammation in females and males that were partially...

Genetic variants affecting microglia can cause early-onset neurodegeneration or elevate Alzheimer's disease risk. To nominate regulators of relevant signaling pathways, we developed a genome-wide CRISPR screen in primary macrophages focused on survival. We identified Ptpn6, which encodes the inhibitory phosphatase SHP-1, as a crucial regulator for macrophage survival under reduced CSF1R signaling conditions in vitro. Deletion of Ptpn6 from adult microglia in vivo enhanced survival and decreased...

The stereochemical diversity of Aβ42 in the brains of patients with Alzheimer's disease (AD) is a clinically recognized but poorly understood phenomenon. A critical gap in our knowledge is how the complex mixture of these stereoisomers collectively influences the aggregation pathway and neurotoxicity of Aβ42 at the molecular level. Drawing from stereoproteome data from AD patient brain tissues and previous studies, we engineered a panel of stereoisomers to more simply simulate the stereochemical...

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Calcium signalling in astrocytes is a fundamental mechanism for maintaining brain homeostasis, shaping neuronal activity, and coordinating vascular and immune responses. Once considered secondary to neuronal signalling, astrocytic Ca^(2+) dynamics are now recognized as highly versatile, spatially compartmentalized and essential for regulating neurotransmitter uptake, ion buffering, metabolic support and mitochondrial function. Accumulating evidence shows that these Ca^(2+) signalling pathways...

Although systemic inflammation has been implicated in PD pathogenesis, the underlying mechanisms remain poorly understood. In this study, we investigate the pathological events in a systemic inflammation-induced PD mouse model. We demonstrate that synaptic loss in the midbrain occurs as early as 1 day after the final lipopolysaccharide (LPS) administration, preceding dopaminergic (DA) neuron degeneration, which was observed only at later stages (14 days). Early microglial activation in the...

Brain aging consists of a progressive loss of functional capacities, which is associated with a progressive cognitive decline and can lead to neurodegenerative diseases. Studies comparing the underlying molecular mechanisms of the human hippocampus between young and older adults remain scarce. In our study, we completed a transcriptomic analysis from hippocampal samples of different ages and performed 2 complementary analyses. A comparison between young and old groups revealed a set of genes...

Astrocytes regulate brain cholesterol homeostasis, but the astrocyte-specific mechanisms disrupted in Alzheimer's disease (AD) are poorly understood. By integrating human bulk transcriptomes with single-nucleus RNA sequencing (RNA-seq), we identified adipocyte enhancer-binding protein 1 (AEBP1) as an astrocyte-enriched factor upregulated in AD. In postmortem human tissue and 5×FAD mice, astrocytic AEBP1 levels rise with age and disease progression. Astrocyte-specific AEBP1 knockdown ameliorates,...

Transplantation-free neuron regeneration remains attractive yet unsolved for reversing Parkinson's disease (PD). Here, we present enzyme-driven mesoporous gold nanomotors (Apyrase@Au) that leverage endogenous biochemical energy for spatiotemporally controlled promotion of neural stem cell (NSC) differentiation, without exogenous stem cell transplantation. By catalyzing endogenous adenosine triphosphate (ATP) hydrolysis, Apyrase@Au nanomotors simultaneously generate directional propulsion and...

Interactions between amyloidogenic proteins are emerging as critical drivers of neurodegenerative diseases. Among others, in Alzheimer's disease (AD) and severe forms of chronic traumatic encephalopathy (CTE), codeposition of tau and amyloid-β (Aβ) leads to worsening of clinical outcomes and disease progression. Despite the importance of such heterotypic interactions, the underlying molecular mechanisms have proven challenging to be established. Here, we investigated the direct interaction...

Transcranial ultrasound stimulation (TUS) is an emerging method for non-invasive neuromodulation of deep brain structures. However, to date, there is no evidence that TUS can directly modulate disease-related pathological oscillations in the same direction as known therapies. Inspired by clinical deep brain stimulation, in this randomised controlled cross-over study we probed the effects of pallidal TUS pulsed at 130 Hz on subthalamic beta-band activity, a biomarker in Parkinson's Disease (PD)...

In early drug discovery, in vitro screening is frequently used, but selected candidates often fail in vivo. Induced pluripotent stem cell (iPSC)-based disease models offer improved physiological relevance; however, the high costs of media and differentiation procedures limit large-scale testing. Here, we develop a high-throughput conditioned-media-based screening system-the High-throughput screening technology for Aggregation Inhibitors of Diseased cell-derived Aggregative Proteins (HaiDap)...

LRRK2 (encoding leucine-rich repeat kinase 2) variants are the most common genetic cause of Parkinson's disease (PD). Lowering LRRK2 levels and/or inhibiting LRRK2 activity may modify PD-associated neuropathology. BIIB094 (ION859), an antisense oligonucleotide, targets LRRK2 mRNA for degradation. REASON was a first-in-human randomized phase 1 study investigating the safety, tolerability, pharmacokinetics and pharmacodynamics of intrathecal BIIB094 in patients with PD. In part A, 40 participants...

Alzheimer's disease (AD) is a highly prevalent progressive neurodegenerative disorder with unclear etiology, complex symptoms, and limited treatment options. Early pathological processes in AD emerge long before the onset of overt cognitive and motor symptoms and involve the accumulation of amyloid-β oligomers and neurofibrillary tangles, accompanied by neuroinflammation and neuronal loss. Importantly, the brain reward system comprises cortical and subcortical structures that share neurochemical...

Neurodegenerative diseases (NDs) pose clinical challenges due to their complexity and molecular heterogeneity. Here, we present a pan-neurodegeneration atlas (PanNDA) from multilayer, deep proteomic analysis of 2,279 human brain samples spanning 6 major NDs: Alzheimer's disease (AD), Lewy body dementia (LBD), frontotemporal lobar degeneration with TDP-43 pathology, progressive supranuclear palsy with tau pathology, vascular dementia, and Parkinson's disease. PanNDA integrates data from whole...

Alterations to the protein and microRNA cargo of extracellular vesicles (EVs) occur in Alzheimer's disease (AD) and may contribute to disease progression. We previously showed that ingestion of amyloid-beta (Aβ) by both murine and human astrocytes leads to alterations to the protein cargo of EVs that induce significant neuronal impairment and apoptosis. Here, we hypothesised that pathological changes to the microRNA cargo of astrocyte-derived EVs (ADEVs) would also occur following exposure of...

β-Amyloid (Aβ) and tau pathologies are hallmark lesions of Alzheimer's disease (AD) and they develop in human brain following differential spatiotemporal trajectories. Accordingly, young/adult-onset tau-independent β-amyloidosis is rare. We encountered four such cases among 397 banked brains, with the donors died of hematological malignances (blood cancers) or cardiovascular diseases. To explore the pathological implication, we examined 17 brains (10-87 year-old, y) from blood cancer patients...

Mutations in PINK1 and PRKN/parkin are the leading recessive causes of Parkinson disease (PD). Together PINK1 and PRKN form a mitophagy pathway for clearing damaged mitochondria from the cell. It was unclear, however, whether diverse forms of mitochondrial damage activate the PINK1-PRKN pathway through a unified mechanism. Recently, we demonstrated that loss of mitochondrial membrane potential (MMP) leads to the stabilization and activation of PINK1 under a wide range of mitochondrial stressors,...