Alzheimer & Parkinson

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...

(250 words) 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...

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...

No abstract

Peptide-based supramolecular nanostructures offer a versatile platform with substantial promise for clinical translation in regenerative medicine. These systems allow for the incorporation of biologically active sequences and can be engineered to modulate tissue-specific parameters such as stiffness, diffusivity, and biodegradability. We developed here a bioactive supramolecular nanostructure containing a peptide designed based on glial cell-derived neurotrophic factor. These nanostructures form...

Clusterin (apolipoprotein J), a conserved glycoprotein abundant in blood and cerebrospinal fluid, functions as a molecular chaperone and apolipoprotein. Dysregulation of clusterin is linked to late-onset Alzheimer disease. Despite its prominent role in extracellular proteostasis, the mechanism of clusterin function remained unclear. Here, we present crystal structures of human clusterin, revealing a discontinuous three-domain architecture. Structure-based mutational analysis demonstrated that...

While clonal hematopoiesis (CH) is associated with protection from Alzheimer's disease (AD), a limited understanding of the mechanisms by which this occurs has been a barrier to therapeutic intervention. In a new study, Matatall et al.¹ discover protective mechanisms by which TET2-mutant, but not DNMT3A-mutant, CH impacts dementia pathology and cognition.

Alzheimer's disease (AD) often begins with non-cognitive symptoms such as olfactory deficits, which can predict later cognitive decline, though the mechanisms remain unclear. Pathologically, the brainstem locus coeruleus (LC), the main source of the neurotransmitter noradrenalin (NA) modulating olfactory information processing is affected early. Here we show early and distinct loss of noradrenergic input to the olfactory bulb (OB) coinciding with impaired olfaction in an AD mouse model, before...

No abstract

Alzheimer's disease (AD) disrupts behavioral circadian rhythms, but its effects on molecular rhythms in the human brain are poorly understood. Using single-nucleus RNA sequencing (snRNA-seq) from post-mortem cortical samples, we informatically estimated the relative circadian phases of 409 persons with and without AD dementia, reconstructing circadian expression profiles across cell types. Although core clock rhythms were preserved in AD, many cell-type-specific circadian outputs were disrupted....

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by dopaminergic neuronal degeneration and pathological α-synuclein accumulation. Mitochondrial dysfunction is a central feature in PD pathogenesis, contributing to impaired bioenergetics, oxidative stress, neuroinflammation, and defective organelle communication. This review synthesizes the current understanding of mitochondrial quality control mechanisms, including fission, fusion, mitophagy, and biogenesis, and their...

Africa stands at a decisive moment in which urgent action is essential to safeguard its brain health and economic stability. While Africa's population remains predominantly young, it is expanding and aging rapidly. This demographic shift is projected to drive a sharp rise in neurodegenerative diseases, including Alzheimer's, with profound health and economic costs-but brain health research, policy, funding and care across the continent remain critically underdeveloped. In this Perspective, we...

Amyloid-related imaging abnormalities (ARIA), side effects of anti-amyloid drugs seen in magnetic resonance imaging of the brain, are a major safety concern in patients with Alzheimer's disease. We developed an antibody transport vehicle (ATV) targeting transferrin receptor (TfR) for brain delivery of anti-amyloid-β protein (anti-Aβ) using asymmetrical Fc mutations (ATV^(cisLALA)) that mitigates TfR-related liabilities and retains effector function when bound to Aβ. Administration of...