Journal of Neuropathology & Experimental Neurology | April 21, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available
Abstract Skin biopsies analyzed with α-synuclein seed amplification assays (SAAs) are a simple way to clinically interrogate the presence of α-synuclein aggregates. We determined the accuracy of skin biopsy SAA in predicting the clinical diagnoses of Parkinson disease (PD), PD with dementia (PDD) and dementia with Lewy bodies (DLB). Blinded SAAs were performed in 3 independent laboratories. Subjects diagnosed with PD, PDD and DLB were analyzed together as group 1, clinically unaffected subjects as group 2 and those with risk factors for LBD as group 3. Punch biopsies were taken from the posterior neck and analyzed by the 3 labs in 6 separate SAAs. Pairwise agreement between labs and assays ranged from excellent (kappa 0.82) to moderate (kappa 0.40-0.68). Sensitivity across assays ranged between 50.0% and 61.3%; specificity ranged between 68.6% and 100%. Comparisons of group 1 vs group 2 produced the greatest specificities, between 77.3% and 100%. In 17 cases that subsequently came to autopsy, 93% of SAAs were positive in those at the neocortical LBD stage but in only <10% of those at lower stages. Skin biopsy α-synuclein SAA may be useful as a diagnostic and progression biomarker in Lewy body dementia clinical trials.
Kv1.3 as an upstream regulator of oxidative stress-mediated neuroinflammation following organic dust exposure in murine in vitro, ex vivo, and in vivo models
Introduction Inhalation of organic dust from concentrated animal production operations induces inflammation in the brain and respiratory tract. We investigated the role of the potassium channel Kv1.3 in models of organic dust (OD)-induced neuroinflammation. Kv1.3 channels play multifaceted roles in microglial immune modulation, cancer, and neurodegenerative diseases, and represent a potential therapeutic target. Methods We used in vivo (C57BL/6 mice), in vitro (microglial cell line, and primary microglia), and ex vivo (brain slice culture) models of OD-induced neuroinflammation. Sterile OD extract (ODE) was prepared, and mice were exposed to either normal saline or ODE intranasally for 5 weeks (5 days/week) to simulate an occupational exposure scenario. Primary microglia were isolated from neonatal mice for total RNA sequencing (RNA-seq). Results The ODE-induced expression of Kv1.3 was quantified using in vitro and ex vivo models with and without PAP-1 treatment. Exposure-induced changes in cytokines and markers of reactive species were measured. Using western blot, we quantified phosphorylated p38 MAPK (p-p38 MAPK) and NOX2. We measured microglial Kv1.3 currents using whole-cell patch-clamp. Exposure to ODE increased the expression of Kv1.3 and p-p38 MAPK in mouse microglia without affecting the Kv1.3 currents at the cell surface. Exposure increased the levels of inflammatory cytokines and NOX2. Kv1.3 inhibition with PAP-1 decreased inflammatory markers (TNF-α in BV2 microglia and IL-6 in Brain slice cultures and BV2 microglia), levels of Kv1.3, p-p38 MAPK, NOX2, and nitrites. Conclusion Our study revealed that pharmacological inhibition of Kv1.3 potassium channels reduces ODE-induced neuroinflammation by decreasing inflammatory and oxidative stress markers.
Exploring the Role of Kv1.3 and MAPK14 in Mediating Microglial Oxidative Stress and Neuroinflammation Following Organic Dust Exposure
Abstract Background Agricultural contaminants, including inhaled organic dust (OD) and gases, are known to cause inflammation in the lungs and the brain. We investigated the role of the potassium channel Kv1.3 in organic dust (OD)-induced neuroinflammation models. Kv1.3 channels play a multifaceted role in microglial immune modulation, cancer, neurodegenerative diseases, and constitute a potential therapeutic target. Methods We used in vivo (C57BL/6 mice), in vitro (microglial cell line, primary microglia), and ex vivo (brain slice culture) models of OD-induced neuroinflammation. A sterile OD extract (ODE) was prepared, and mice were exposed to either normal saline or ODE intra-nasally for 5 weeks (5 days/week) to simulate an occupational exposure scenario. Primary microglia were isolated from neonatal mice for total RNA sequencing (RNA-seq). The ODE-induced expression of Kv1.3 was quantified using in vitro and ex vivo models with and without PAP-1 treatments. Exposure-induced changes in cytokines and reactive species markers were measured. Using western blot, we quantified phosphorylated p38 MAPK14 (p-p38 MAPK) and NOX2. We measured the currents through Kv1.3 channels using a microglial patch-clamp assay. Results Exposure to ODE increased the expression of Kv1.3 and p-p38 MAPK in mouse microglia without affecting the Kv1.3 currents at the cell surface. Exposure increased the levels of inflammatory cytokines and NOX2. Kv1.3 inhibition with PAP-1 decreased inflammatory markers (TNF-α and IL-6), levels of Kv1.3, p-p38 MAPK, NOX2, and nitrites. Conclusion Our study revealed that pharmacological inhibition of Kv1.3 potassium channels reduces ODE-induced neuroinflammation by decreasing inflammatory and oxidative stress markers.
Central and peripheral α‐synuclein in Parkinson disease detected by seed amplification assay
AbstractObjectivesDetection of α‐synuclein aggregates by seed amplification is a promising Parkinson disease biomarker assay. Understanding intraindividual relationships of α‐synuclein measures could inform optimal biomarker development. The objectives were to test accuracy of α‐synuclein seed amplification assay in central (cerebrospinal fluid) and peripheral (submandibular gland) sources, compare to total α‐synuclein measures, and investigate within‐subject relationships.MethodsThe Systemic Synuclein Sampling Study aimed to characterize α‐synuclein in multiple tissues and biofluids within Parkinson disease subjects (n = 59) and compared to healthy controls (n = 21). Motor and non‐motor measures and dopamine transporter scans were obtained. Four measures of α‐synuclein were compared: seed amplification assay in cerebrospinal fluid and formalin‐fixed paraffin‐embedded submandibular gland, total α‐synuclein quantified in biofluids using enzyme‐linked immunoassay, and aggregated α‐synuclein in submandibular gland detected by immunohistochemistry. Accuracy of seed amplification assay for Parkinson disease diagnosis was examined and within‐subject α‐synuclein measures were compared.ResultsSensitivity and specificity of α‐synuclein seed amplification assay for Parkinson disease diagnosis was 92.6% and 90.5% in cerebrospinal fluid, and 73.2% and 78.6% in submandibular gland, respectively. 25/38 (65.8%) Parkinson disease participants were positive for both cerebrospinal fluid and submandibular gland seed amplification assay. Comparing accuracy for Parkinson disease diagnosis of different α‐synuclein measures, cerebrospinal fluid seed amplification assay was the highest (Youden Index = 83.1%). 98.3% of all Parkinson disease cases had ≥1 measure of α‐synuclein positive.Interpretationα‐synuclein seed amplification assay (cerebrospinal fluid>submandibular gland) had higher sensitivity and specificity compared to total α‐synuclein measures, and within‐subject relationships of central and peripheral α‐synuclein measures emerged.
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)
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