Alzheimer & Parkinson

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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...

A modified antibody targeting amyloid-β reduces adverse events and increases efficacy in a mouse model.

Parkinson's disease (PD) is characterized by inclusions of α-synuclein (α-syn) and mitochondrial dysfunction in dopaminergic (DA) neurons of the substantia nigra pars compacta (SNpc). Patients with PD anecdotally experience symptom improvement at high altitude; chronic hypoxia prevents the development of Leigh-like brain disease in mice with mitochondrial complex I deficiency. Here we report that intrastriatal injection of α-syn preformed fibrils (PFFs) in mice resulted in neurodegeneration and...

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Insulin resistance is a risk factor for Alzheimer's disease (AD). Chen et al.¹ show that microglial insulin signaling is essential for metabolic homeostasis and immune regulation, while insulin resistance impairs Aβ clearance and promotes neuroinflammation in AD. Their findings reframe AD pathogenesis through a cell-type-specific lens.

The earliest molecular changes in Alzheimer's disease (AD) are poorly understood^(1-5). Here we show that endogenous lithium (Li) is dynamically regulated in the brain and contributes to cognitive preservation during ageing. Of the metals we analysed, Li was the only one that was significantly reduced in the brain in individuals with mild cognitive impairment (MCI), a precursor to AD. Li bioavailability was further reduced in AD by amyloid sequestration. We explored the role of endogenous Li in...

Autophagic decline accompanies age and causes a deterioration in proteostasis, rendering neuronal demise. Rab27 functions as a vesicle regulator for macroautophagic/autophagic degradation and exocytosis. Loss of Drosophila Rab27 in αβp brain neurons enhances longevity, underscoring its neuronal role and systemic effect. To understand the underlying mechanisms, we characterized the cell autonomous and non-autonomous functions of Rab27. Rab27 expression increased in midlife, providing a temporal...

The renin-angiotensin system (RAS), an important regulator of body fluid and cardiovascular homeostasis, is gradually implicated in the pathogenesis of neurological diseases due to its dysregulation. In addition to their traditional functions, components of the RAS, especially angiotensin-II (Ang-II), enhance neuroinflammation, oxidative stress, and neuronal injury. Ang-II exacerbates blood-brain barrier (BBB) disruption, promotes glial activation, and contributes to neurodegeneration via the...

Cerebrospinal fluid (CSF) α-synuclein (α-syn) seed amplification assays (SAAs) can detect Lewy body pathology (LBP) with high accuracy but are invasive and costly. To address these challenges, this study evaluated a two-step workflow combining prescreening via smell-function testing with confirmatory CSF α-syn SAA testing only in individuals with reduced smell, for predicting postmortem LBP status. Among 358 autopsied participants, the two-step workflow predicted brain LBP with high accuracy...

Leucine-rich repeat kinase 2 (LRRK2) is an essential regulator in cellular signaling and a major contributor to Parkinson's disease (PD) pathogenesis. 14-3-3 proteins are critical modulators of LRRK2 activity, yet the structural basis of their interaction has remained unclear. Here, we present the cryo-electron microscopy structure of the LRRK2:14-3-3(2) autoinhibitory complex, revealing how a 14-3-3 dimer stabilizes an autoinhibited LRRK2 monomer through dual-site anchoring. The dimer engages...

Accumulation of amyloid-β (Aβ) peptides and hyperphosphorylated tau proteins in the hippocampus triggers cognitive memory decline in Alzheimer's disease (AD). The incidence and mortality of sporadic AD were tightly associated with diabetes and hyperlipidemia, while the exact linked molecular mechanism is uncertain. Here, the present investigation identified significantly elevated serum Kallistatin levels in AD patients concomitant with hyperglycemia and hypertriglyceridemia, suggesting potential...

Microglia are resident immune cells of the brain and are implicated in the etiology of Alzheimer's disease (AD) and other diseases. Yet the cellular and molecular processes regulating their function throughout the course of the disease are poorly understood. Here, we present a transcriptional analysis of primary microglia from 189 human postmortem brains, including 58 healthy aging individuals and 131 with a range of disease phenotypes, such as 63 patients representing the full clinical and...

Parkinson's Disease (PD) is an incurable neurodegenerative disease that causes movement disorders. Neurons in PD aggregate α-synuclein and are depleted from the substantia nigra (SN), which is a movement control hub. The presence of α-synuclein-reactive T cells in PD patient blood suggests a role for adaptive immunity in the pathogenesis of PD. However, the characteristics of this response within the brain are not well understood. Here, we employed single-nucleus RNAseq, spatial transcriptomics,...

Caloric restriction slows or prevents Alzheimer's disease in animal models. Calorie restriction is typically implemented in rodents through feeding once per day; as the animals quickly consume their food, they are subject to a prolonged self-imposed fasting period between meals. Here, we examine the distinct contributions of fasting and reduced calories to the beneficial effects of calorie restriction on Alzheimer's disease by placing male and female 3xTg and non-transgenic control mice on a...

Ribosome-associated quality control (RQC) is a pivotal biological process that governs the fidelity of messenger RNA (mRNA) homeostasis and protein synthesis. Defects in RQC are implicated in cellular dysfunction and proteotoxicity, but their impact on aging remains elusive. Here, we show that Pelota, the ribosome rescue factor, promotes longevity and protects against age-related pathological phenotypes in multiple metazoan species. By performing a targeted genetic screen, we find that Pelota is...