Alzheimer & Parkinson

Mutations in the phospholipase A2 group VI (PLA2G6) gene have been linked to autosomal recessive Parkinson's disease (PD), yet the molecular mechanisms remain poorly understood. This study provides the in vitro and in vivo evidence, specifically in dopaminergic neurons derived from patients with PD, that PLA2G6 loss-of-function disrupts the mitochondria-associated endoplasmic reticulum (ER) membrane (MAM), a critical regulator of Ca^(2+) transfer and energy homeostasis. This study demonstrates...

Biomolecular condensates formed via liquid-liquid phase separation (LLPS) are essential for cellular organization. α-Synuclein, an amyloidogenic protein linked to Parkinson's Disease (PD), undergoes phase separation at high concentrations, but the influence of lipid membranes on this process remains unclear. Here, combining in vitro reconstitution, cell biology, and simulations, we show that membranous interfaces promote α-Synuclein condensation at physiologically relevant sub-critical...

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Transglutaminase 2 (TG2) is implicated in synucleinopathies including Parkinson's disease (PD) and dementia with Lewy bodies, as it promotes α-Synuclein (α-Syn) aggregation in vitro, and evidence for its activity is detected in Lewy bodies in human postmortem brains. Additionally, TG2 overexpression exacerbates α-Syn toxicity in double transgenic mice, while TG2 deletion mitigates the phenotype of α-Syn transgenic mice. Considering that TG2 is a multidomain and multifunctional protein, the...

Mitochondrial transplantation holds significant potential for the treatment of mitochondrial diseases. However, how to efficiently deliver exogenous mitochondria to somatic cells or tissues remains unresolved. We present a mitochondrial transplantation approach to deliver mitochondria into the cells and tissues of mice and monkeys with high efficiency, based on encapsulating mitochondria with vesicles derived from the plasma membrane of erythrocytes. Treatment with encapsulated mitochondria...

Neurofibrillary tangles, composed of excessively phosphorylated tau, are a core neuropathological hallmark of Alzheimer's disease (AD). However, therapeutic strategies aimed at directly clearing neurofibrillary tangles have demonstrated limited clinical efficacy, shifting the research focus towards the fundamental underlying mechanism- the dysregulation of tau phosphorylation. Evidence indicates that tau physiological phosphorylation is indispensable for microtubule stability and normal neuronal...

White matter (WM) is a key substrate for interregional neural communication and cognitive function but the role of WM glucose metabolism in cognitive aging has been understudied. Using multimodal neuroimaging (MRI, FDG-PET, amyloid-PET) from 3142 participants (15,287 visits) across two studies, we examined the contribution of WM to cognition and identified divergent WM signatures. Higher glucose metabolism in expected WM (EWM; corpus callosum and cingulum) was associated with better cognition,...

Alzheimer's Disease (AD) is a neurodegenerative condition affecting millions worldwide. Defining early pathobiological events remains challenging, in part due to inaccessibility of neural tissue. Because olfactory neurons are accessible, and olfactory loss is prevalent in AD, we evaluated olfactory brush biopsies from controls, individuals with cerebrospinal fluid (CSF) biomarker-confirmed AD, and cognitively typical individuals whose positive CSF biomarkers signal a pre-clinical AD stage. Here...

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Hyperphosphorylated Tau aggregates are a central pathological hallmark of Alzheimer's disease (AD), yet no approved therapy directly targets this process. mRNA therapeutics provide a transient and non-viral option but are limited by the blood-brain barrier (BBB). TRIM11 is an ATP-independent disaggregase that dissolves pathological Tau fibrils and promotes proteasomal clearance. Here, a ligand-free lipid nanoparticle (PLNP) is developed with zwitterionic, acetylcholine-mimetic...

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...

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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...