Journal of Neuropathology and Experimental Neurology最新文献

Intracranial aneurysms (IAs) affect 1%-5% of the public and are a major cause of subarachnoid hemorrhage. Currently, there is no medical treatment to prevent the progression or rupture of IAs. Recent studies have defined IA as a chronic inflammatory disease in which macrophages infiltrate intracranial arteries via the CCL2-CCR2 axis. The chemokine signal regulator FROUNT mediates this axis, and it can be inhibited by the anti-alcoholism drug disulfiram. Therefore, inhibition of macrophage infiltration by interfering with FROUNT using disulfiram may represent a strategy to prevent exacerbation of IAs. Here, effects of disulfiram were investigated in vitro and in an animal model of IAs. FROUNT expression was observed on infiltrated macrophages both in human IAs and in the rat IA model by immunohistochemistry. In vitro treatment with disulfiram suppressed CCL2-mediated migration of cultured rat macrophages in a transwell system. Disulfiram administered in a rat model of IAs inhibited both the initiation and the enlargement of IAs in a dose-dependent manner; this was accompanied by suppression of macrophage infiltration. These results suggest that pharmacological inhibition of the CCL2-CCR2-FROUNT signaling cascade could be a treatment of patients with IAs.

High-grade infiltrating gliomas are highly aggressive and fatal brain tumors that present significant challenges for research and treatment due to their complex microenvironment and tissue structure. Recent discovery of tumor microtubes (TMs) has provided new insights into how high-grade gliomas develop in the brain and resist treatment. TMs are unique, ultra-long, and highly functional membrane protrusions that form multicellular networks and play crucial roles in glioma invasiveness, drug resistance, recurrence, and heterogeneity. This review focuses on the different roles that TMs play in glioma cell communication, material transport, and tumor cell behavior. Specifically, non-connecting TMs primarily promote glioma invasiveness, likely related to their role in enhancing cell motility. On the other hand, interconnecting TMs form functional and communication networks by connecting with surrounding astrocytes and neurons, thereby promoting glioma malignancy. We summarize the factors that influence the formation of TMs in gliomas and current strategies targeting TMs. As the understanding of TMs advances, we are closer to uncovering whether they might be the long-sought Achilles' heel of treatment-resistant gliomas. By delving deeper into TMs research, we hope to develop more effective therapeutic strategies for patients with malignant gliomas.

In situ hybridization (ISH) staining of bacterial 16S ribosomal RNA (rRNA) is an alternative to standard histological stains (eg, Gram, Warthin-Starry), and may improve the diagnosis of bacterial brain abscesses. To evaluate the utility of 16S rRNA ISH, a 10-year retrospective cohort was assembled from a large academic medical center. Results of histological stains, cultures, and 16S rRNA sequencing were extracted from reports, and new Gram and 16S rRNA ISH stains were performed. Histologically identifiable bacteria were present in 40/63 (63%) cases and 38/57 (67%) were associated with positive cultures. Overall, 16S rRNA ISH was positive in 18/63 (29%) cases, including 16/37 (43%) with positive Gram stains, 12/38 (32%) positive by culture, and 4/8 (50%) positive by sequencing. 16S rRNA ISH highlighted bacteria in 14/40 (35%) cases with Gram-positive organisms and 9/17 (53%) with Gram-negative organisms (including 6 polymicrobial cases). Compared to a composite gold standard of Gram stain and culture, the sensitivity and specificity of 16S rRNA ISH were 35% and 93%, respectively. While sensitivity is relatively low, 16S rRNA ISH may be useful for distinguishing real organisms from artifacts and for identifying brain abscess cases suitable for 16S rRNA sequencing.

Ischemic stroke results in inhibition of axonal regeneration but the roles of fibrinogen (Fg) in neuronal signaling and energy crises in experimental stroke are under-investigated. We explored the mechanism of Fg modulation of axonal regeneration and neuronal energy crisis after cerebral ischemia using a permanent middle cerebral artery occlusion (MCAO) rat model and primary cortical neurons under low glucose-low oxygen. Behavioral tests assessed neurological deficits; immunofluorescence, immunohistochemistry, and Western-blot analyzed Fg and protein levels. Fluo-3/AM fluorescence measured free Ca2+ and ATP levels were gauged via specific assays and F560nm/F510nm ratio calculations. Mito-Tracker Green labeled mitochondria and immunoprecipitation studied protein interactions. Our comprehensive study revealed that Fg inhibited axonal regeneration post-MCAO as indicated by reduced GAP43 expression along with elevated free Ca2+, both suggesting an energy crisis. Fg impeded mitochondrial function and mediated impairment through the EGFR/Ca2+ axis by trans-activating EGFR via integrin αvβ3 interaction. These results indicate that the binding of Fg with integrin αvβ3 leads to the trans-activation of the EGFR/Ca2+ signaling axis thereby disrupting mitochondrial energy transport and axonal regeneration and exacerbating the detrimental effects of ischemic neuronal injury.

The prevalence of focal granule cell bilamination (FGCB) in the hippocampal dentate gyrus varies from 0% to 44%, depending on age and study population. FGCB is commonly thought to be a specific feature of temporal lobe epilepsy (TLE) but its prevalence in cases without TLE is unclear. Using formalin-fixed, paraffin-embedded hippocampal sections, this retrospective postmortem study evaluated the prevalence of FGCB and other granule cell pathologies in infants (1-12 months of age, n = 16), children (4-10 years, n = 6), and adults (28-91 years, n = 15) with no known history of epilepsy or seizures. We found FGCB in 6% of infants, 17% of children, and 27% of adults. We then compared our findings with those in published reports of sudden unexpected deaths in infancy (SUDI), childhood (SUDC), and epilepsy (SUDEP), and in surgical specimens from patients with TLE. The reported prevalence of FGCB in those studies was 6%-19% in infants, 0%-17% in children, and 0%-2% in adults in non-seizure-related cases and 9% in children and 3%-25% in adults with TLE. Our findings highlight the presence of FGCB in individuals with no known epilepsy/seizure-related histories in proportions similar to those reported in individuals with clinical epilepsy.

This review discusses terminology recently proposed for the classification of dementia and, more specifically, nosology related to aging-associated TDP-43 pathology: limbic-predominant age-related TDP-43 encephalopathy (LATE), and limbic-predominant amnestic neurodegenerative syndrome (LANS). While the "gold standard" for these clinical conditions is still LATE neuropathologic changes (LATE-NC), clinical criteria and biomarkers are evolving. The newly proposed clinical rubrics are discussed with emphasis on the need for terminology that acknowledges the distinctions between clinical syndrome-, molecular biomarker-, and pathologically defined disease concepts. As further progress is made on research into the specific biomarker-based detection and prediction of TDP-43 proteinopathy in the clinical setting, the definitions of "Probable" and "Possible" LATE are likely to become more useful clinically. For people interested in the pathological diagnoses or basic research related to LATE-NC, the relevant terminology remains unchanged by the newly proposed clinical criteria.

Neuropathic pain arises as a consequence of injury or disease in the peripheral or central nervous system. Clinical cases have shown that spine postoperative chronic neuropathic pain remains a troublesome issue in medical treatment due to the presence of various degrees of peridural fibrosis and different inflammatory factors after spinal surgery. To address this issue, we developed a new neuropathic mice model that successfully simulates the real clinical situation by applying oxidative regenerative cellulose to L5 DRG (dorsal root ganglion). Behavior tests were done by von Fray and thermal stimuli. ELISA and real-time PCR were employed to detect the expression of genes involved in neuropathic pain. This model not only successfully induces chronic pain but also causes membrane thickening, non-neuronal cell recruitment, and a local increase of TNFα and interleukin-6. Additionally, this model did not cause neuron loss in the affected DRG, which mimics the characteristics of sticky tissue-induced neuropathic pain after clinic surgery. Based on this model, we administrated a TNF inhibitor to mice and successfully reduced mechanical allodynia after DRG surgery. In this study, the developed animal model may be a novel platform for delivering neuropathic pain treatments, such as target-based drug discovery or personalized diagnostic approaches.