Alzheimer & Parkinson

The protein α-synuclein, encoded by SNCA, accumulates in Parkinson's disease (PD) and other synucleinopathies for reasons that remain unclear. Here, we investigated whether SNCA is regulated in vivo by the RNA-binding protein PUM1. We establish that PUM1 binds to SNCA's 3' UTR in mouse and human cells. In induced neurons from patients with SNCA locus triplication, PUM1 mRNA levels are lower than in healthy controls, but increasing PUM1 normalizes both SNCA mRNA and α-synuclein protein levels,...

Alzheimer's disease and related dementias (AD/ADRDs) pose a significant global public health challenge. To effectively implement personalized therapeutic interventions on a global scale, it is essential to identify disease-causing, risk, and resilience factors across diverse ancestral backgrounds. This study leveraged biobank-scale data to conduct a large multi-ancestry whole-genome sequencing characterization of AD/ADRDs. We thoroughly explored the role of protein-coding and splicing variants...

The innate immune system can develop a form of memory called priming, where prior exposure to a stimulus enhances subsequent responses. While well-characterized in peripheral immunity, its function in brain-resident cells such as astrocytes under non-disease conditions remains unclear. Here we show that human astrocytes derived from the induced pluripotent stem cells of healthy female donors, but not microglia, acquire a primed state following transient immune stimulations. Upon subsequent...

Late-onset depression (LOD) is closely linked to Alzheimer's disease (AD), marked by shared biological pathways and common risk factors. The neurobiological alterations associated with depression, particularly the dysregulation of amyloid-β (Aβ), play a critical role in the acceleration of disease progression. In individuals suffering from LOD, Aβ peptides - specifically Aβ40 and Aβ42 - exhibit distinct profiles in plasma, cerebrospinal fluid (CSF), and brain tissue, highlighting the substantial...

The "Christchurch" protective variant in the APOE gene has recently been identified, but its mechanisms of action remain unknown. In this issue of Immunity, Naguib and Lopez-Lee et al. provide evidence for the APOE-Christchurch variant suppressing microglial cGAS-STING responses and increasing clearance of pathological tau aggregates in mouse models of Alzheimer's disease.

Hyposmia, a common non-motor symptom in Parkinson's disease (PD) linked to reduced odor sensitivity, is associated with brain structural and functional changes, but dynamic brain activity and altered regional information exchange remain underexplored, limiting insight into underlying brain states. We selected 15 PD patients with severe hyposmia (PD-SH), 15 PD patients with normal cognition (PD-CN), and 15 healthy controls (HC). Using functional MRI, we assessed the brain's spatiotemporal...

False positive claims of differentially expressed genes (DEGs) in scRNA-seq studies are of substantial concern. We found that DEGs from individual Parkinson's (PD), Huntington's (HD), and COVID-19 datasets had moderate predictive power for case-control status of other datasets, but DEGs from Alzheimer's (AD) and Schizophrenia (SCZ) datasets had poor predictive power. We developed a non-parametric meta-analysis method, SumRank, based on reproducibility of relative differential expression ranks...

The meninges serve as a critical interface between the peripheral immune system and the central nervous system, playing a crucial role in maintaining parenchymal homeostasis. Neurodegenerative disorders, such as amyloidosis and tauopathies, are marked by the accumulation of extracellular neurotoxic amyloid-β (Aβ) plaques and intracellular tau tangles, respectively, leading to neuronal cell death and cognitive decline. The role of the adaptive immune response in these pathologies remains under...

CONCLUSIONS: Our study highlights the complex relationship between genetic legacies and modern diseases, emphasizing the need for gender-sensitive healthcare strategies that consider the unique connections between female reproductive health and aging.

Many brain disorders involve mitochondrial alterations, but owing to the lack of suitable tools, the causal role of mitochondrial dysfunction in pathophysiological processes is difficult to establish. Heterotrimeric guanine nucleotide-binding (G) proteins are key regulators of cell functions, and they can be found within mitochondria. Therefore, we reasoned that the activation of stimulatory mitochondrial G proteins (G(s)) could rapidly promote the activity of the organelle and possibly...

Neurodegenerative diseases such as Alzheimer disease (AD), Parkinson disease, frontotemporal lobar degeneration and multiple system atrophy (MSA) are characterized pathologically by deposition of specific proteins in the brain. Five major neurodegenerative disease-associated proteins - amyloid-β (Aβ), tau, α-synuclein, TAR DNA-binding protein 43 (TDP43) and fused in sarcoma (FUS) - are commonly encountered, and the disease specificity and neurotoxicity of the fibrillar protein assemblies are...

Extracellular release and uptake of pathogenic forms of the microtubule-associated protein tau contribute to the pathogenesis of several neurodegenerative diseases, including Alzheimer's disease. Defining the cellular mechanisms and pathways for tau entry to human neurons is essential to understanding tauopathy pathogenesis and enabling the rational design of disease-modifying therapeutics. Here, whole-genome, loss-of-function CRISPR screens in human iPSC-derived excitatory neurons, the major...

Cellular senescence is a major contributor to aging-related degenerative diseases, including Alzheimer's disease (AD), but much less is known about the key cell types and pathways driving senescence mechanisms in the brain. We hypothesized that dysregulated cholesterol metabolism is central to cellular senescence in AD. We analyzed single-cell RNA-seq data from the ROSMAP and SEA-AD cohorts to uncover cell type-specific senescence pathologies. In ROSMAP snRNA-seq data (982,384 nuclei from...

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive dysfunction, with spatial memory impairments among the earliest detectable deficits. The dentate gyrus (DG), a critical region for spatial discrimination, exhibits functional alterations in patients with AD. Adult-born granule cells (abGCs) with higher intrinsic excitability are involved in DG-dependent spatial memory. However, it remains unclear the changes in intrinsic excitability of abGCs and...

Alzheimer's disease (AD) diagnosis hinges on detecting amyloid beta (Aβ) plaques and neurofibrillary tau (τ) tangles, typically assessed using PET imaging. While accurate, these modalities are expensive and not widely accessible, limiting their utility in routine clinical practice. Here, we present a multimodal computational framework that integrates data from seven distinct cohorts comprising 12, 185 participants to estimate individual PET profiles using more readily available neurological...

Many models of aging assume that processes such as cellular senescence or epigenetic alteration occur under sterile conditions. However, humans sustain infection with viral, bacterial, fungal, and parasite pathogens across the course of a lifetime, many of which are capable of long-term persistence in host tissue and nerves. These pathogens-especially members of the human virome like herpesviruses, as well as intracellular bacteria and parasites-express proteins and metabolites capable of...

Mutations in the genes encoding APP, Presenilin-1 (PSEN1), and PSEN2 result in early-onset Alzheimer's disease (AD). Previous studies, using iPSC-derived neurons and/or knock-in mice, elucidated the characteristics of neurons expressing familial AD (fAD) mutations. Here, we employ biochemical and state-of-the-art fluorescence imaging assays and report the discovery of a unique subpopulation of wild-type neurons strikingly recapitulating key phenotypes previously identified in the fAD neurons,...

Mutations that disrupt the clearance of damaged mitochondria via mitophagy are causative for neurological disorders including Parkinson's. Here, we identify a Mitophagic Stress Response (MitoSR) activated by mitochondrial damage in neurons and operating in parallel to canonical Pink1/Parkin-dependent mitophagy. Increasing levels of mitochondrial stress trigger a graded response that induces the concerted degradation of negative regulators of autophagy including Myotubularin-related phosphatase...

Parkinson's disease (PD) is characterized by the accumulation and spread of pathological α-synuclein (α-syn) fibrils, which contribute to neuroinflammation and neurodegeneration. Here we show that two immunoglobulin-like (Ig-like) domains derived from α-syn receptors, the D1 domain of lymphocyte-activation gene 3 (L3D1) and the V domain of advanced glycation end-products (vRAGE), effectively block cell surface binding of α-syn fibrils, suppress fibrils-induced neuronal α-syn aggregation, and...

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