Alzheimer & Parkinson

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...

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Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, yet its epigenetic underpinnings remain elusive. Here, we generate and integrate single-cell epigenomic and transcriptomic profiles of 3.5 million cells from 384 postmortem brain samples across 6 regions in 111 AD and control individuals. We identify over 1 million candidate cis-regulatory elements (cCREs), organized into 123 regulatory modules across 67 cell subtypes. We define large-scale...

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Emerging gene-editing technologies, such as the CRISPR system, represent a potential pathway for precision medicine targeting the genetic and molecular causes of diseases. Second-generation CRISPR technologies, including base editing, prime editing, and engineered Cas variants, have improved fidelity and offer alternative strategies for precise gene correction, transcriptional repression or activation, and modulation of pathological pathways in neurodegeneration. These tools can correct...

Personality changes are a clinical criterion for dementia diagnosis, yet their progression across disease stages remains unclear. This systematic review and meta-analyses examined change in the five major personality traits across the preclinical, transitional, and clinical dementia stages. We conducted pre-registered searches of three databases from their inception to November 2024. The standardized mean difference (SMD) with 95 % CIs were combined in random-effects meta-analyses. Prospective...

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid plaques and neurofibrillary tangles. Recent evidence implicates extracellular matrix (ECM) dysfunction in disease pathogenesis, including extensive loss of perineuronal nets (PNNs). PNNs are neuron-ensheathing condensed ECM structures composed of chondroitin sulfate proteoglycans, including the main constituent aggrecan (ACAN). To explore the role of PNNs in AD, we utilize the 5xFAD model and genetically target Acan...

CONCLUSIONS: DBS significantly improved motor, neuropsychological, and quality-of-life outcomes across all PD durations, with the most substantial benefits observed in mid-duration (5-10 years) patients. While levodopa response was a consistent positive prognostic factor for motor response, caution is warranted for short-duration patients with rapidly progressive motor symptoms, as they exhibited less favorable outcomes.

Microglia are crucial targets for therapeutic interventions in diseases like Alzheimer's and stroke, but efficient gene delivery to these immune cells is challenging. We developed an adeno-associated virus (AAV) vector that achieves specific and efficient gene delivery to microglia. This vector incorporates the mIba1 promoter, GFP, miRNA target sequences (miR.Ts), WPRE, and poly(A) signal. Positioning miR.Ts on both sides of WPRE significantly suppressed non-microglial expression, achieving over...

A DNA editing tool TaqTth-hpRNA was developed in this study, composed of a compact recombinant TaqTth nuclease (832 aa) and a simple hairpin-RNA guiding probe (hpRNA). In vitro biochemical studies showed the TaqTth-hpRNA efficiently cleaves artificially synthesized single-stranded DNA without stringent sequence motif like protospacer adjacent motif (PAM). It can also cleave the genomic DNA of Escherichia coli with ∼80% efficiency. The TaqTth-hpRNA cleavage of genomic DNA in mammalian cells...