Alzheimer & Parkinson

The dominantly inherited Flemish mutation-an A692G substitution in the amyloid precursor protein, corresponding to an A21G change in amyloid-β (Aβ)-causes a rare, early-onset form of Alzheimer disease characterized by pronounced cerebral amyloid angiopathy and unusually large senile plaque cores. Here, we report cryo-electron microscopy structures of amyloid filaments extracted from the postmortem parietal lobes of two individuals representing the only two known Flemish pedigrees worldwide....

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Hyperphosphorylation and aggregation of tau are pathological hallmarks of tauopathies. Mitochondrial dysfunction is also a common feature of tauopathies. The mechanistic link between tau abnormalities and mitochondrial dysfunction and its relationship to the physiological function of tau, however, is unclear. Here, we demonstrate that tau regulates mitochondrial reverse electron transport (RET), which produces excess reactive oxygen species (ROS), reduces the NAD^(+)/NADH ratio, and is activated...

Alzheimer's disease (AD) is a slow-progressing neurodegenerative disease, mainly characterized by the accumulation of amyloid beta (Aβ) plaques and intracellular hyperphosphorylated Tau protein, along with the generation of free radicals. In normal physiology free radicals play a promising role. However, the imbalance in the formation and clearance of the free radicals or reactive oxygen species/reactive nitrogen species (ROS/RNS) disrupts redox homeostasis, resulting in oxidative stress....

The primary mechanism and subcellular localisation of α-synuclein toxicity in Parkinson's disease pathogenesis remain unknown. We spatially and temporally resolved proteomic and transcriptomic changes in human iPSC-derived dopaminergic neurons with increasing burden of pathological α-synuclein. We found that misfolded α-synuclein proteoforms, signified by the formation of nanoscale intraneuronal puncta, are associated with impaired translocon function at the endoplasmic reticulum (ER). We show...

Mutations in lysosomal enzyme glucocerebrosidase (GBA), the most common genetic risk factor for Parkinson disease (PD), exacerbate α-synuclein pathology through unclear mechanisms. Here, we report, in a large cohort, that GBA-mutated PD patients exhibit lower serum cholesterol levels. By introducing the most common GBA variant in our cohort, L444P, into human α-synuclein knock-in mice, we noted that the mice exhibited behavioral and molecular pathological PD features at 12 months of age....

Mitochondrial dysfunction and abnormal energy metabolism are important pathological features of Alzheimer's disease (AD). This study investigates how mitochondrial protease YME1L1 affects mitochondrial function and its upstream regulation in the pathogenesis of AD. The AD model was established by using APP/PS1 transgenic mice, primary neurons treated with Aβ1-42, and HT22 cells. The silencing of YME1L1 was achieved to evaluate its effects on mitochondrial function and OPA1 protein hydrolysis....

Parkinson's disease (PD) is a multisystemic disorder that manifests through motor and non-motor symptoms. Motor dysfunction results from the degeneration of dopamine-producing neurons in the substantia nigra pars compacta. Increasing evidence suggests that synapse dysfunction precedes neuronal loss by years. Still, early synaptic alterations in PD remain poorly understood. Here, we integrate literature meta-analysis and multi-omics with biochemical, imaging, and electrophysiological measurements...

SQSTM1/p62 (sequestosome 1) is an important receptor protein involved in many cellular signaling processes, including macroautophagy/autophagy. It is a molecular hub for cellular homeostasis and cellular responses. Within autophagy, SQSTM1 targets ubiquitinated cargo for degradation, maintaining cellular proteostasis. Structurally, SQSTM1 consists of several domains that facilitate its binding to ubiquitinated cargo, the formation of SQSTM1 aggregate inclusions, interactions with MAP1LC3/LC3,...

Microglia are key players in Alzheimer's disease, but the transcriptional control of their phagocytic function remains unclear. Kim et al. show that mouse microglial Spi1 deletion worsens amyloid pathology by impairing Aβ clearance through Syk, Lyn, and Fcgr1, providing new insight into PU.1-dependent regulatory networks and microglial functions in neurodegeneration.

Increasing evidence indicates that shifts in brain polysaccharide metabolism can influence the progression of multiple neurodegenerative diseases. Here, we profile corpora amylacea (CA) in 230 postmortem human brains, revealing significantly higher densities in Alzheimer's disease (AD) patients when compared with patients with other or no neurodegenerative diseases and a tight correlation of CA density with neurofibrillary tangle (NFT) pathology. Immunohistochemical profiling using an...

Alzheimer's disease (AD) exhibits substantial clinical and pathological heterogeneity that is not fully explained by amyloid-β and tau pathology alone. TAR DNA-binding protein 43 (TDP-43) is increasingly recognized as a frequent copathology in AD, particularly in limbic regions, where its presence is associated with accelerated cognitive decline. Disruption of mitochondrial homeostasis is also an early and consistent feature of AD and contributes to neuronal vulnerability. In this review, we...

We investigated how patients with Parkinson's disease (PD) manage the explore-exploit trade-off in a structured reward-learning task. Patients were tested either on (n = 34) or off (n = 34) dopaminergic medication (levodopa), with age-matched polyneuropathy patients serving as controls (n = 35). Behaviorally, patients off medication showed marked learning and decision-making deficits, characterized by overexploration (excessive sampling of novel options) and insufficient exploitation...

Stem-cell-based in vitro models offer promising potential to elucidate human brain cell functions and interactions, but limitations in reproducibility, maturation and cell-type diversity persist. Especially, prolonged incorporation of mature microglia and studies of neuroinflammation have proven challenging. Here, we developed a human induced pluripotent stem cell-based three-dimensional cortical brain tissue model (3BTM) containing neurons, astrocytes and microglia with high reproducibility,...

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Hypothesis generation in biomedicine is constrained by human cognitive limitations in synthesizing insights from fragmented biomedical knowledge and multimodal data sources. Here we introduce XunZi, an AI biologist that integrates logical reasoning and multimodal data fusion to autonomously generate de novo therapeutic target hypotheses with testable mechanisms. XunZi has been trained on 24.4 million publications and 613.6 TB of multisource data spanning 21,008 human genes and 5,850 diseases,...

Metabolic dysfunction is a defining but poorly understood feature of Alzheimer's disease. Du et al. show that a brain-penetrant GLP-1 receptor agonist rewires astrocyte-neuron metabolic coupling through lactate-driven histone lactylation, linking astrocytic glycolysis to neuronal lipid homeostasis and positioning metabolite signaling as a therapeutic axis in neurodegeneration.

Alzheimer's disease (AD), as the leading cause of dementia, poses an increasingly severe socioeconomic burden in the context of global ageing. Traditionally defined by amyloid-β and tau pathology, it's increasingly recognized as a systems disorder in which impaired glucose metabolism, mitochondrial dysfunction, and neuroinflammation interact across neural cell types and disease stages. However, the interaction among these three mechanisms, their role in promoting the classical pathology of AD,...

Metabotropic glutamate receptor subtype 5 (mGlu5) is an important regulator of excitatory neurotransmission and remains a therapeutic target for neuropsychiatric and neurological disorders, including substance use disorders, depression, Fragile X syndrome, Parkinson's disease-related dyskinesia, and other movement disorders. However, the clinical development of mGlu5 negative allosteric modulators (NAMs) has been limited by translational challenges, inconsistent efficacy, and safety concerns,...

Postural and locomotor dysfunction represent axial symptoms of Parkinson's disease (PD), which remain poorly treated by medication and deep brain stimulation. Whilst non-invasive neuromodulation of the vestibular system via the vestibular nucleus complex (VNC) offers a novel therapeutic avenue, the underlying circuits are still poorly characterized. Here we show that the mouse VNC feeds extensive Vglut2-defined projections into striato-thalamo-subthalamic and caudal medulla motor hubs and...