Alzheimer & Parkinson

Microtubule-associated tau (MAP) is a crucial component for cellular cytoskeleton stability. However, upon hyperphosphorylation, these tau proteins detach from microtubules, leading to the genesis of clumpy fibrillar-rich β or paired helical filamental structures known as amyloids. Such deposits predispose a multitude of fatal disorders, including Alzheimer's Disease. The initial event behind such genesis is still a mystery. Today, numerous research studies try to untangle the initial events...

The second near-infrared (NIR-II) dyes provide advantages for in vivo imaging, but challenges persist. A primary issue is the lack of practicable strategies to balance emission wavelength and molecular weight, particularly for low-molecular-weight (<500 Da) NIR-II (λ(em) > 1000 nm) dyes. Here, we propose a strategy that tunes NIR-II emissions by reducing Coulomb attraction interaction, contrasting with traditional approaches that redshift absorption wavelengths through energy gap reduction....

Microglia-driven dysregulation has emerged as a significant underlying mechanism in many neurodegenerative diseases, such as age-related macular degeneration (AMD) and Alzheimer's disease (AD). Although both brain and retinal microglia originate from the yolk sac, it is uncertain whether they share molecular similarities or genetic and molecular foundations related to neurodegenerative diseases. In this study, we examine the transcriptomic and epigenetic profiles of retina and brain microglia...

A hallmark of Alzheimer's disease (AD) is the accumulation of extracellular amyloid-β plaques in the brain. Amyloid-β is a 40-42 amino acid peptide generated by proteolytic processing of amyloid precursor protein (APP) via membrane-bound proteases. APP is a transmembrane protein, and its trafficking to sites of proteolysis represents a rate-limiting step in AD progression. Although APP processing has been well-studied, its trafficking itinerary and machinery remain incompletely understood. To...

A growing body of evidence shows that epileptic activity is frequently observed in patients with Alzheimer's disease (AD), implicating underlying excitatory-inhibitory imbalance. The distinction of whether the AD-epileptic phenotype represents a subset of patients or an underdiagnosed manifestation holds major therapeutic implications. Here, we quantified the excitatory-inhibitory imbalance in AD patients using magnetoencephalography and examined the relationships to AD...

Parkinson's disease (PD) is characterized by the death of substantia nigra pars compacta (SNc) dopamine (DA) neurons, but the pathophysiological mechanisms that precede and drive their death remain unknown. The activity of DA neurons is likely altered in PD, but we understand little about if or how chronic changes in activity may contribute to degeneration. To address this question, we developed a chemogenetic (DREADD) mouse model to chronically increase DA neuron activity and confirmed this...

Levodopa-induced dyskinesia (LID) is a complication that occurs in many patients with Parkinson's disease. (-)-OSU6162 is a clinically tolerable dopamine stabilizer with affinity for both dopaminergic D(2) receptors and serotonergic 5-HT(2A) receptors which has been shown to counteract LID in non-human primates. To investigate whether (-)-OSU6162 can dampen levodopa-induced abnormal involuntary movements in the unilateral 6-OHDA rat model of Parkinson's disease without impairing levodopa-induced...

MicroRNAs (miRNAs) have emerged as key regulators of neuroplasticity, influencing essential processes such as neurogenesis, synaptogenesis, and neuroinflammatory responses. This review provides a comprehensive overview of the general roles of miRNAs in neuroplasticity and synthesizes recent insights from both preclinical and clinical studies, including transcriptomic analyses and miRNA profiling, to elucidate the molecular mechanisms by which these miRNAs modulate neuronal function. We have...

Nucleoside Reverse Transcriptase Inhibitors (NRTIs), widely used to treat HIV and hepatitis B, have recently been shown to possess anti-inflammatory properties by inhibiting inflammasome activation. Epidemiological studies have revealed a significantly reduced incidence of age-related diseases, such as Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM), among patients chronically treated with NRTIs, but not with other classes of antiretroviral drugs. In this short review, we explore...

Alzheimer's disease (AD) and AD-related dementias (AD/ADRD) have a substantial genetic basis, with APOE4 homozygotes increasingly recognized as a distinct genetic subtype. To identify genotype-specific metabolic pathways and modifiable risk factors, we integrated genetic, plasma metabolomic and dietary data from 4,215 women and 1,490 men in prospective cohorts. Here we show that the associations of 57 metabolites with dementia risk varied by APOE4 genotype or other AD/ADRD risk variants. For...

The spreading of MAPT/Tau pathology is closely associated with the progression of neurodegeneration and cognitive decline in Alzheimer disease and other tauopathies. A key event in this process is the rupture of endolysosomal vesicles following the intercellular transfer of MAPT/Tau aggregates, releasing the transferred MAPT/Tau species into the cytosol where they can promote the aggregation of endogenous MAPT/Tau. However, understanding of the cellular pathways involved in this process remains...

ATP13A2 is an endolysosomal polyamine transporter mutated in several neurodegenerative conditions involving lysosomal defects, including Parkinson's disease (PD). While polyamines are polybasic and polycationic molecules that play pleiotropic cellular roles, their specific impact on lysosomal health is unknown. Here, we demonstrate lysosomal polyamine accumulation in ATP13A2 knockout (KO) cell lines and human induced pluripotent stem cell (iPSC)-derived neurons. Primary polyamine storage caused...

A blood biomarker-based staging system for Alzheimer's disease (AD) could improve the diagnosis, prognosis and identification of individuals most likely to benefit from specific therapies. Here, using targeted mass spectrometry, we measured six phosphorylated and six nonphosphorylated tau peptides in plasma from two independent cohorts: BioFINDER-2 and TRIAD (n = 689). We also analyzed the ratios of phosphorylated to nonphosphorylated peptides. Our results revealed that specific tau species...

Increasing evidence strongly links neuroinflammation to Alzheimer's disease (AD) pathogenesis. Peripheral monocytes are crucial components of the human immune system, but their contribution to AD pathogenesis is still largely understudied partially due to limited human models. Here, we introduce human cortical organoid microphysiological systems (hCO-MPSs) to study AD monocyte-mediated neuroinflammation. By culturing doughnut-shape organoids on 3D-printed devices within standard 96-well plates,...

Age-related neurodegeneration is one of the primary causes associated with the pathogenesis of Alzheimer's disease (AD). Currently, there are 5.8 million cases of AD worldwide. With the advancement in technology, the paradigm of treating the disease has shifted from one treatment or diagnosis to simultaneously diagnosing as well as treating the disease. Excellent efforts have been made by the scientists towards the development of nanotheranostics. Among them, quantum dots (QDs) have shown...

The complicated pathogenesis of Alzheimer's disease (AD) is characterized by the accumulation of neurofibrillary tangles and senile plaques, primarily composed of tau and amyloid-β (Aβ) aggregates, respectively. While substantial efforts have focused on unraveling the individual roles of tau and Aβ in AD development, the intricate interplay between these components remains elusive. Here we report how the microtubule-binding repeats of tau engage with Aβ in a distinct manner. Crucially, this...

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Functional gene programs play a wide range of roles in health and disease by orchestrating transcriptional coregulation to govern cell identity. Understanding these intricate gene programs is essential for unraveling the complexities of biological systems; however, deciphering them remains a significant challenge. Recent advancements in single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics (ST) technologies have empowered the comprehensive characterization of gene programs at both...

Proteomic profiling of Alzheimer disease (AD) brains has identified numerous understudied proteins, including midkine (MDK), that are highly upregulated and correlated with amyloid-β (Aβ) from the early disease stage but their roles in disease progression are not fully understood. Here, we present that MDK attenuates Aβ assembly and influences amyloid formation in the 5xFAD amyloidosis mouse model. MDK protein mitigates fibril formation of both Aβ40 and Aβ42 peptides according to thioflavin T...

Presynaptic terminals can be located far from the neuronal cell body and are thought to independently regulate protein and organelle turnover. Autophagy is a critical process for maintaining proteostasis, and its synaptic dysregulation is associated with neurodegenerative diseases. In this work, we report a soma-centered mechanism that regulates autophagy-controlled protein turnover at distant presynaptic terminals in Drosophila. We show that a central component of this system is Rab39, whose...