Blood inflammation relates to neuroinflammation and survival in frontotemporal lobar degeneration

Nanocarrier-based targeted drug delivery for Alzheimer's disease: addressing neuroinflammation and enhancing clinical translation

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, amyloid-beta (Aβ) aggregation, tau pathology, and chronic neuroinflammation. Among these, neuroinflammation plays a crucial role in exacerbating disease progression, making it an attractive therapeutic target. However, the presence of the blood-brain barrier (BBB) significantly limits the effective delivery of therapeutic agents to the brain, necessitating novel drug delivery strategies. Nanocarrier-based delivery systems have emerged as a promising solution to these challenges, offering targeted drug transport, enhanced BBB penetration, and improved bioavailability while minimizing systemic toxicity. This review explores the current advancements in nanocarrier-mediated drug delivery for AD, focusing on the mechanisms of neuroinflammation, the role of nanocarriers in overcoming the BBB, and their ability to modulate inflammatory pathways. Furthermore, the review discusses preclinical validation strategies and key challenges, including safety concerns, large-scale production limitations, and regulatory hurdles that must be addressed to enable clinical translation. Future perspectives emphasize the integration of nanotechnology with precision medicine, gene therapy, and artificial intelligence to optimize nanocarrier design for individualized AD treatment. By overcoming these obstacles, nanocarriers hold the potential to revolutionize therapeutic approaches for AD and other neurodegenerative diseases.

Peripheral innate immunophenotype in neurodegenerative disease: blood-based profiles and links to survival

The innate immune system plays an integral role in the progression of many neurodegenerative diseases. In addition to central innate immune cells (e.g., microglia), peripheral innate immune cells (e.g., blood monocytes, natural killer cells, and dendritic cells) may also differ in these conditions. However, the characterization of peripheral innate immune cell types across different neurodegenerative diseases remains incomplete. This study aimed to characterize peripheral innate immune profiles using flow cytometry for immunophenotyping of peripheral blood mononuclear cells in n = 148 people with Alzheimer's disease (AD), frontotemporal dementia (FTD), corticobasal syndrome (CBS), progressive supranuclear palsy (PSP), Lewy body dementia (LBD) as compared to n = 37 healthy controls. To compare groups, we used multivariate dissimilarity analysis and principal component analysis across 19 innate immune cell types. We identified pro-inflammatory profiles that significantly differ between patients with all-cause dementia and healthy controls, with some significant differences between patient groups. Regression analysis confirmed that time to death following the blood test correlated with the individuals' immune profile weighting, positively to TREM2+ and non-classical monocytes and negatively to classical monocytes. Taken together, these results describe transdiagnostic peripheral immune profiles and highlight the link between prognosis and the monocyte cellular subdivision and function (as measured by surface protein expression). The results suggest that blood-derived innate immune profiles can inform sub-populations of cells relevant for specific neurodegenerative diseases that are significantly linked to accelerated disease progression and worse survival outcomes across diagnoses. Blood-based innate immune profiles may contribute to enhanced precision medicine approaches in dementia, helping to identify and monitor therapeutic targets and stratify patients for candidate immunotherapies.

Lack of relationships between ketamine treatment and peripheral neurotrophic and inflammatory factors in a randomized controlled ketamine trial of major depressive disorder

BACKGROUND

Ketamine is a rapid-acting treatment for treatment-resistant depression (TRD), though mechanisms related to ketamine's effects remain unclear. Blood-based neurotrophic and inflammatory factors (NIFs; e.g., brain-derived neurotrophic factor, interleukin-6) have emerged as markers potentially linked to ketamine and ketamine treatment response.

METHODS

In this secondary analysis of a randomized controlled trial (RCT), 133 adults with TRD received a single-dose infusion of ketamine (n = 89; 0.5 mg/kg) or saline (n = 44) and provided measures of peripheral blood NIF levels and depression severity across a five-day post-infusion period. Differences between ketamine and saline groups were examined for (1) NIF levels, (2) associations between NIF trajectories and depression score trajectories, and (3) associations between baseline NIF levels and depression score trajectories. Subgroup sensitivity analyses examined identical relationships within many (n = 28) discrete subgroups of individuals.

RESULTS

No differences were found between ketamine and saline cohorts for NIF trajectories, associations of NIF and depression trajectories, or associations of baseline NIF levels and depression trajectories. On subgroup analyses, in participants with lower BMI (BMI < 25; n = 66), increasing interleukin-1 receptor antagonist (IL-1RA) trajectories post-ketamine were associated with less improvement in depression in the first day post-infusion.

DISCUSSION

Associations between ketamine treatment and peripheral neurotrophic/inflammatory factors were not detected in our RCT of 133 adults with TRD. The sole exception across exhaustive sensitivity analyses was that, in individuals with low BMI, increases in IL-1RA levels may be linked to worse immediate treatment response. Future research investigating CNS-specific NIF activity is needed to more definitively test the posited role of NIFs in ketamine's antidepressant mechanisms.

From Stress to Synapse: The Neuronal Atrophy Pathway to Mood Dysregulation

Mood disorders, including major depressive disorder and bipolar disorder, are among the most prevalent mental health conditions globally, yet their underlying mechanisms remain incompletely understood. This review critically examines the neuronal atrophy hypothesis, which posits that chronic stress and associated neurobiological changes lead to structural and functional deficits in critical brain regions, contributing to mood disorder pathogenesis. Key mechanisms explored include dysregulation of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), elevated glucocorticoids from stress responses, neuroinflammation mediated by cytokines, and mitochondrial dysfunction disrupting neuronal energy metabolism. These processes collectively impair synaptic plasticity, exacerbate structural atrophy, and perpetuate mood dysregulation. Emerging evidence from neuroimaging, genetic, and epigenetic studies underscores the complexity of these interactions and highlights the role of environmental factors such as early-life stress and urbanization. Furthermore, therapeutic strategies targeting neuroplasticity, including novel pharmacological agents, lifestyle interventions, and anti-inflammatory treatments, are discussed as promising avenues for improving patient outcomes. Advancing our understanding of the neuronal atrophy hypothesis could lead to more effective, sustainable interventions for managing mood disorders and mitigating their global health burden.

Novel blood-based proteomic signatures across multiple neurodegenerative diseases

INTRODUCTION

Blood-based biomarkers have the potential to support early and accurate diagnoses of neurodegenerative diseases, which are sensitive to molecular pathology and are predictive of outcome. We evaluated a novel multiplex proteomic method in people with diverse neurodegenerative diseases.

METHODS

Serum from people with Alzheimer's disease (N = 36), Lewy body dementia (N = 34), frontotemporal dementia (N = 36), and progressive supranuclear palsy (N = 36) and age-matched controls (N = 30) was analyzed with the nucleic acid linked immuno-sandwich assay (NULISA) central nervous system panel (≈ 120 analytes) and inflammation panel (250 analytes). Biomarkers were compared across groups and included as predictors of survival.

RESULTS

The NULISA panels demonstrated high sensitivity and reliability for detecting multiple biomarkers across neurodegenerative disorders. There were condition-specific proteomic biomarkers, while neurofilament light chain, corticotropin-releasing hormone, CD276, and a data-driven inflammation pattern were significant transdiagnostic outcome predictors.

DISCUSSION

The sensitive NULISA multiplex approach supports differential diagnosis and target identification, with prognostically informative dementia-related biomarkers.

HIGHLIGHTS

We tested the novel technology nucleic acid linked immuno-sandwich assay (NULISA) in people with diverse neurodegenerative diseases, which demonstrated high sensitivity and reliability for detecting multiple biomarkers in serum samples. We compared the NULISA central nervous system serum results to single molecule array (Simoa) plasma assays for phosphorylated tau (p-tau)217, p-tau231, neurofilament light chain (NfL), and glial fibrillary acidic protein, finding strong correlations. Increased levels of serum NfL were identified across all patient groups and most elevated in the frontotemporal dementia (FTD) and progressive supranuclear palsy (PSP) cohorts, while p-tau epitopes were the most significant markers in patients with Alzheimer's disease (AD) and Lewy body dementia. Patients with FTD and PSP showed upregulation of many inflammation markers, compared to controls and patients with AD. We found condition-specific proteomic biomarkers, while NfL, corticotropin-releasing hormone, CD276, and data-driven immune signatures were significant transdiagnostic predictors of clinical outcomes (survival rates).