Alzheimer & Parkinson

Amyloid fibrils formed by the islet amyloid polypeptide cause pancreatic beta-cell damage, resulting in reduced insulin secretion and type 2 diabetes. Changes in the amino acid sequence of this peptide can influence its aggregation rate, and animals expressing variants that do not form amyloids do not develop type 2 diabetes. Conversely, specific single amino acid changes can accelerate the aggregation rate of this peptide. Here, we employ deep mutational scanning to measure the ability of 1916...

Neuro-immune crosstalk is increasingly recognized in Parkinson's disease (PD), and ATP13A2 is well known for its neuroprotective role. However, it remains unclear whether ATP13A2 mutations carried by PD patients contribute to immune dysfunction that exacerbates disease progression. Here, we systematically demonstrate that many ATP13A2 mutations result in a loss-of-expression phenotype. ATP13A2 is highly expressed in macrophages. Myeloid ATP13A2 deficiency causes uncontrolled NLRP3 inflammasome...

Protein phosphatase 2A (PP2A) regulates Tau hyperphosphorylation in Alzheimer's disease (AD). This study hypothesized that exercise increases adiponectin levels, activating PP2A to reduce Tau hyperphosphorylation and enhance hippocampal plasticity. The study utilized adiponectin knockout (Adipo^(-/-)) and hippocampal-specific PP2A knockdown (PP2A-KD) in mice with 3-week voluntary running and/or chronic stress to assess changes in Tau phosphorylation, adult neurogenesis, and cognitive...

Single-cell spatial transcriptomes have demonstrated molecular and cellular diversity in the brain, but gene regulatory mechanisms underlying transcriptomic profiles and disease pathogenesis remain largely unknown in primates. Here we performed single-nucleus Assay for Transposase-Accessible Chromatin followed by sequencing (snATAC-seq) for ~1.6 million cells from 142 cortical regions of two male cynomolgus monkeys (Macaca fascicularis), and identified distinct chromatin accessibility profiles...

Losing track of personal experiences is a defining feature of Alzheimer disease (AD), arising from the spread of AD pathology through the brain circuits that support episodic memory. In this Review, we explore strategies to improve the function of episodic memory circuits in AD by leveraging the optimized use of neural resources. We introduce the circuit utilization framework, which builds on evidence that synaptic dysfunction, maladaptive responses and deficient adaptive plasticity contribute...

Parkinson's disease (PD) is a debilitating neurodegenerative condition that results in a loss of mobility and muscle control. A neuropathological hallmark of PD is the presence of aberrant inclusions, known as Lewy pathology, of which α-synuclein (α-Syn) is a major component. The accumulation of α-Syn may be due to an imbalance in the proteostasis system regulating α-Syn. To investigate this hypothesis, we delineated the proteostasis network (PN) of α-Syn in the human substantia nigra at the...

No abstract

Alzheimer's disease (AD), an age-associated neurodegenerative disorder, is characterized by progressive cognitive decline, amyloid-β (Aβ) accumulation (including soluble oligomers and deposited aggregates), lipid dysregulation, and neuroinflammation. Although mutations in the amyloid precursor protein (APP) and accumulation of Aβ42 are established drivers of pathology, the mechanisms connecting oligomeric amyloid toxicity with lipid metabolism and inflammatory responses remain poorly understood....

Neuroinflammation is a pathological feature of neurodegenerative diseases like Alzheimer's disease and ALS. Cytoplasmic dsRNA (cdsRNA) triggers a type-I interferon response in human neural cells, leading to their death, and is found in neurons of C9ORF72-ALS patients. Here, we report the spatial coincidence of cdsRNA and pTDP-43 inclusions in human postmortem tissue with Alzheimer's disease pathology, and upregulated interferon response genes in affected regions. CdsRNA also accumulates in a...

The connection between aging and immune dysfunction is uncovering how immunoaging processes contribute to disease. Recent data from Alzheimer’s disease, Parkinson’s disease, and adult and pediatric glioblastomas reveal a novel role for TIM3 in brain immune alteration. These findings highlight the role of TIM3 in promoting myeloid cell dysfunction toward an immunosuppressive profile. TIM3-blocking antibody treatments for central nervous system pathologies could be a new therapeutic window for...

Type 1 diabetes, particularly with childhood onset, is associated with altered neurocognitive traits, yet the underlying biological mechanisms are unclear. Here, we integrate genome-wide association results with single-cell epigenomic profiles and show that type 1 diabetes heritability is enriched in accessible chromatin of human brain-resident cells, most notably microglia, across neurodevelopment into adulthood. Bonferroni-corrected cross-trait genetic correlation analyses reveal negative...

Aging is the strongest risk factor for chronic diseases such as cardiovascular disease, Alzheimer's, and cancer. DNA methylation (DNAm) clocks offer a promising measure of biological age, but most rely on linear models that miss non-linear dynamics and CpG interactions. To address this, we developed a deep neural network (DNN)-based DNAm clock trained on 29,167 samples profiled on Illumina EPIC v1.0 and v2.0 arrays. Using 12,234 CpGs selected through sex- and age-stratified correlations, our...

Deep brain stimulation (DBS) is an effective treatment for Parkinson's disease (PD) but its neural mechanisms remain poorly understood. A mechanistic understanding requires precise characterization of functional responses to various stimulation conditions within the same individual. Here we use 3-T magnetic resonance imaging (MRI)-compatible DBS and precision imaging to collect extensive data from 14 patients with PD who received DBS. Across five timepoints spanning 1 year, each patient...

Neurofibrillary tangles (NFTs) formed from the protein tau disrupt neuronal function in Alzheimer's disease and are strongly associated with cognitive decline. Early events in tau aggregation are increasingly linked to the formation of biomolecular condensates, which lower the energetic barriers to pathological aggregation by acting as intermediates that transition into insoluble assemblies, a mechanism also implicated in other neurodegenerative diseases, such as amyotrophic lateral sclerosis...

Transcriptome-wide association studies (TWAS) have successfully identified genes associated with complex traits and diseases, but most have been performed using bulk gene expression data, which aggregate signals across heterogeneous cell types. Population-scale single-cell RNA sequencing data now make it possible to perform TWAS at the cell-type resolution, but present unique challenges due to strong noises, technical variations, and high sparsity. Here, we propose scTWAS, a statistical method...

Traditional Alzheimer's disease (AD) research has predominantly focused on neuronal pathology within the amyloid-tau-neurodegeneration (ATN) framework, emphasizing β-amyloid (Aβ) plaques, neurofibrillary tangles (NFTS), and neuroinflammation as primary drivers of disease progression. Recently, converging evidence suggests that oligodendrocytes (OLs) and myelin abnormalities are not merely downstream consequences of neuronal injury. Instead, OL dysfunction may emerge early and actively shape...

Recent advances suggest a correlation between gut dysbiosis and neurological diseases, however, relatively little is known about how gut bacteria impact the brain. Here, we reveal that bacteria can translocate directly from the gut to the brain in small numbers when mice are fed an atherogenic, high-fat diet (Paigen diet) that causes alterations in gut microbiome composition and gut barrier permeability. The bacteria were not found in other systemic sites or the blood, but were detected in the...

Acute stress triggers the release of cortisol, which broadly affects cognitive processes. Path integration, a specific navigational process, relies heavily on grid cells in the entorhinal cortex. The entorhinal cortex contains glucocorticoid receptors and is therefore likely to be influenced by cortisol, though little is known about this relationship. Given the role of the entorhinal cortex in neurological diseases such as Alzheimer's Disease, investigating the effects of cortisol on this brain...

Detecting small extracellular vesicles is critical for understanding disease biology and developing diagnostic tools, yet current methods require lengthy isolation steps and lack sensitivity owing to interference from abundant proteins. Here we report on an assay that uses Janus particles that enable rapid, isolation-free detection by exploiting Brownian rotation-induced blinking changes. When vesicles bind, their size significantly alters the blinking frequency, while smaller proteins produce...

Elevated blood levels of phosphorylated tau (p-tau) are diagnostic of Alzheimer disease and are associated with the deposition of amyloid-β in the cerebral neuropil. Elevated p-tau levels have also been associated with cerebral deposition of Danish amyloid and prion protein amyloid. Here we analyzed p-tau in serum from four different cohorts of people with the most common types of systemic amyloidosis, transthyretin (ATTR) amyloidosis and immunoglobulin light chain (AL) amyloidosis. We found...