Brain Pathology最新文献

Disability worsening in multiple sclerosis (MS) is linked to neurodegeneration. Cholesterol homeostasis is essential for normal brain function. CYP46A1, crucial for brain cholesterol turnover and reduced in some neurodegenerative diseases, is a potential neuroprotective target. We hypothesized that CYP46A1 is downregulated in MS brains and linked to cholesterol dysbalance. Mass spectrometric analysis of sterols was performed from matched plasma and cerebrospinal fluid (CSF) in an all-female MS cohort (n = 32, mean age = 33). Disability status was recorded at baseline and follow-up. MS brain tissue samples (n = 11; 7 females; ages 38-67; 10 Secondary Progressive MS, 1 Primary Progressive MS; Disease Duration: 13-49 years) and control samples (n = 8; 3 females; ages 41-68) analysed for pathological regions using mass spectrometry and RNA expression using in-situ hybridization. Significant dysregulation in 25-hydroxycholesterol, 27-hydroxycholesterol and 3β-hydroxycholestenoic acid in CSF correlated with disability at baseline and follow-up in the patient population. In brain tissue, reduced cholesterol, 24S-hydroxycholesterol and 24S,25-epoxycholesterol were observed in white matter lesions (p < 0.05), linked to CYP46A1 activity. CYP46A1 expression was enriched in neurons, with reductions in MS grey matter lesions and non-lesions compared to controls (p < 0.01). Cholesterol metabolism is dysregulated in MS and is associated with reduced neuron-specific CYP46A1 expression. Modulating CYP46A1, a druggable target, may benefit progressive MS.

DNA methylation profiling by Illumina methylation array-based methods has revolutionized the molecular classification and diagnosis of brain tumors. A significant barrier to adopting these methods in a clinical environment is the requirement for specialized scanners, which results in high additional costs and a larger laboratory footprint. DNA sequencing-based alternatives are attractive because most clinical molecular pathology laboratories already use sequencers for other molecular assays. This study aimed to compare the utility of the newly developed sequencing-based enzymatic methyl sequencing (EM-seq) method paired with the Twist Human Methylome panel for brain tumor classification with standard Infinium Methylation BeadChip-based methods. We used DNA from fresh-frozen or formalin-fixed, paraffin-embedded (FFPE) brain cancer samples from 19 patients and 1 control sample to construct DNA libraries covering 3.98 million CpG sites. We developed and validated a bioinformatics pipeline to analyze target-enriched EM-seq (TEEM-seq) data in comparison with standard array-based methods for tumor classification and copy number profiling. We found high concordance between TEEM-seq and traditional methods, with high correlation coefficients (>0.98) between FFPE replicates. We successfully classified tumor samples into the expected molecular classes with robust prediction scores (>0.82). We observed that FFPE samples required a sequencing depth of at least 35x to achieve consistently high and reliable prediction scores. The TEEM-seq method has the potential to complement existing tumor classification methods and lower the barriers for the adoption of methylation profiling in routine clinical use.

Glioblastomas are known for their immunosuppressive tumor microenvironment, which may explain the failure of most clinical trials in the past decade. Recent studies have emphasized the significance of stratifying glioblastoma patients to predict better therapeutic responses and survival outcomes. This study aims to investigate the prognostic relevance of peripheral immune cell counts sampled prior to surgery, with a special focus on methylation-based subclassification. Peripheral blood was sampled in patients with newly diagnosed (n = 176) and recurrent (n = 41) glioblastoma at the time of surgery and analyzed for neutrophils, monocytes, leukocytes, platelets, neutrophil-lymphocyte ratio, lymphocyte-monocyte ratio, and platelet-lymphocyte ratio. Peripheral immune cell counts were correlated with patients' survival after combined radiochemotherapy. In addition, 850 k genome-wide DNA methylation was assessed on tissue for defining tumor subclasses and performing cell-type deconvolution. In newly diagnosed glioblastoma, patients with higher peripheral neutrophil counts had an unfavorable overall survival (OS) (p = 0.01, median overall-survival (mOS) 17.0 vs. 10.0 months). At the time of first recurrence, a significant decrease of peripheral immune cell counts was observed, and elevated monocyte (p = 0.03), neutrophil (p = 0.04), and platelet (p = 0.01) counts were associated with poorer survival outcomes. DNA methylation subclass-stratified analysis revealed a significant survival influence of neutrophils (p = 0.007) and lymphocytes (p = 0.04) in the mesenchymal (MES) subclass. Integrating deconvolution of matched tumor tissue showed that platelets and monocytes were correlated with a more differentiated, tumor-progressive cell state, and peripheral immune cell counts were most accurately reflected in tissue of the MES subclass. This study illustrates a restricted prognostic significance of peripheral immune cell counts in newly diagnosed glioblastoma and a constrained representation in matched tumor tissue, but it demonstrates a more pertinent situation at the time of recurrence and after DNA methylation-based stratification.

Oxidized regenerated cellulose (ORC; marketed as Surgicel® and Tabotamp®) is routinely used as an intraoperative hemostatic agent. Rarely, residual ORC has been associated with a foreign body reaction generating cystic or granulomatous lesions (i.e., textilomas) at the surgical site. Here, we report a bedside-to-bench, translational report of an intracranial mass after neurosurgical resection of glioblastoma with ORC application. As part of patient care, we performed magnetic resonance imaging and histopathological analysis of the mass. We then performed in vitro studies to evaluate the effect of ORC on cytokine production and viability of BV-2 murine microglial cells by using quantitative PCR along with live cell microscopy and crystal violet staining, respectively. Magnetic resonance imaging demonstrated a recurrent mass pressing on the adjacent right ventricle, which was removed in a second surgery for diagnostic and therapeutic purposes. Unexpectedly, histopathological examination of the resected mass revealed abundant ORC arising from the site with inflammation, microglial activation, and collagenization. Mechanistically, we show an ORC-induced modest increase in inflammatory cytokines with a subsequent decrease in microglial cell viability. These findings suggest that ORC may mediate microglial immune response and viability, and serve to raise awareness and guide interpretation of post-treatment surveillance imaging findings in the instance of foreign body reaction.

The shift toward a histo-molecular approach in World Health Organization classification of central nervous system tumors (WHO CNS5) emphasizes the critical role of molecular testing, such as next-generation sequencing (NGS) and DNA methylation profiling, for accurate diagnosis. However, implementing these advanced techniques is particularly challenging in resource-constrained countries. To address this, the Asian Oceanian Society of Neuropathology committee for Adapting Diagnostic Approaches for Practical Taxonomy in Resource-Restrained Regions (AOSNP-ADAPTR) was initiated to help pathologists in resource-limited regions to implement WHO CNS5 diagnoses using simpler diagnostic tools, mainly immunohistochemistry. An online survey by this group assessed the in-house/local availability of diagnostic resources and outsourcing capabilities across the Asian Oceanian region, covering 19 countries. Of 318 responding centers, the availability of molecular techniques in-house/locally was limited in lower middle-income countries (LMICs), with 29% having fluorescence in situ hybridization, 10.7% Sanger sequencing, and only 9.4% NGS. DNA methylation was largely unavailable in-house/locally in of LMICs, while in the whole region, its availability stood at a meager 4.4%. Though outsourcing for all diagnostic tests was an easily accessible alternative, outsourcing for NGS and DNA methylation was uncommon because of the financial burden on patients being a significant obstacle. The survey categorized centers into five resource levels (RLs) based on the in-house/local access to diagnostic techniques, which highlighted the variability and disparity in diagnostic capabilities across the region. High-income countries had 80% of centers with advanced RL IV, V resources, in contrast to LMICs, where 70.5% of centers fell into RL I-III. This comprehensive evaluation emphasizes the need for tailored resource level guidelines, with the aim of improving diagnostic accuracy and treatment as well as advocating better healthcare infrastructure in resource-constrained areas. However, the survey's reliance on responses from better-resourced centers may underestimate challenges in lower-resource settings, stressing the need for broader outreach and support.