Central nervous system germ cell tumors (CNS-GCT) are malignant neoplasms that arise predominantly during adolescence and young adulthood. These tumors are typically sensitive to treatment, but resulting long-term health deficits are common. Additional clinical challenges include surgical risks associated with tumor biopsy, and need to determine treatment response for adapting radiotherapy protocols. The aim of this study was to establish the detectability of circulating-tumor DNA (ctDNA) from cerebrospinal fluid (CSF) of children with CNS-GCT as a potential biomarker. We obtained CSF from patients with CNS-GCT by lumbar puncture or intra-operatively. Cell-free DNA (cfDNA) was extracted and subjected to low-pass whole genome sequencing (LP-WGS). Copy-number alterations (CNAs) were inferred and served as a marker of measurable residual disease (MRD). Comparisons with imaging findings and tumor marker levels were made. A total of 29 CSF samples from 21 patients (16 with germinoma, 5 with non-germinomatous GCT) were sequenced. Twenty samples from 19 patients were collected at diagnosis, and 9 samples from 7 patients were collected during or after therapy. Among the diagnostic samples, CNAs were detected in samples from 17/19 patients (89%), which included 8 with marker-negative tumors. Specific clinical scenarios suggested that serial cfDNA analysis may carry utility in tracking treatment responses as well as clarifying indeterminate imaging findings. Our results provide evidence for the high-sensitivity in detecting ctDNA from CSF of CNS-GCT patients using LP-WGS, with potential utility for non-invasive diagnosis and disease monitoring in upcoming CNS-GCT studies.

Amyotrophic Lateral Sclerosis (ALS) is a devastating neurodegenerative disorder characterized by the progressive loss of motor neurons, with genetic and environmental factors contributing to its complex pathogenesis. Dysregulated immune responses and altered energetic metabolism are key features, with emerging evidence implicating the gut microbiota (GM) in disease progression. We investigated the interplay among genetic background, GM composition, metabolism, and immune response in two distinct ALS mouse models: 129Sv_G93A and C57Ola_G93A, representing rapid and slow disease progression, respectively.Using 16 S rRNA sequencing and fecal metabolite analysis, we characterized the GM composition and metabolite profiles in non-transgenic (Ntg) and SOD1 mutant mice of both strains. Our results revealed strain-specific differences in GM composition and functions, particularly in the abundance of taxa belonging to Erysipelotrichaceae and the levels of short and medium-chain fatty acids in fecal samples. The SOD1 mutation induces significant shifts in GM colonization in both strains, with C57Ola_G93A mice showing changes resembling those in 129 Sv mice, potentially affecting disease pathogenesis. ALS symptom progression does not significantly alter microbiota composition, suggesting stability.Additionally, we assessed systemic immunity and inflammatory responses revealing strain-specific differences in immune cell populations and cytokine levels.Our findings underscore the substantial influence of genetic background on GM composition, metabolism, and immune response in ALS mouse models. These strain-specific variations may contribute to differences in disease susceptibility and progression rates. Further elucidating the mechanisms underlying these interactions could offer novel insights into ALS pathogenesis and potential therapeutic targets.

Astroblastoma, MN1-altered, is a rare circumscribed glial neoplasm that is composed of round, cuboidal, orcolumnar cells with astroblastic perivascular pseudorosettes, often associated with MN1::BEND2 and MN1::CXXC5 fusions. Atroblastoma-like gliomas harbouring EWSR1::BEND2 have been reported that they defined an epigenetically distinct subtype of astroblastoma. We report a case of a 19-year-old female with an intracranial neuroepithelial tumor featuring a novel TCF3::BEND2 fusion. This tumor, while classified as EWSR1::BEND2 gliomas based on DNA methylation, did not exhibit the MN1 alteration or typical astroblastoma morphology. The patient, initially diagnosed as ependymoma WHO grade 2 following surgery for an intracranial tumor four years prior, presented with a suspected recurrence. Magnetic resonance imaging identified a mixed solid-cystic lesion in the temporal area of the left lateral ventricle. For the recurrent tumor, the histological examination revealed the tumor cells predominantly exhibited a solid arrangement, with the solid areas primarily consisting of oval and short-spindle cells. In certain regions, loosely arranged short-spindle cells was observed. The tumor exhibited high cellular density, nuclear atypia, and frequent mitoses, but lacked the hallmark features typically associated with astroblastoma. Immunohistochemistry revealed patchy positivity for GFAP and OLIG2, diffuse positivity for EMA, and a high MIB-1 labeling index. Genome-wide DNA methylation profiling confirmed the tumor's classification as EWSR1::BEND2 gliomas with a high-confidence match and revealed focal deletion of chromosome 9q. Targeted next-generation sequencing identified a TCF3::BEND2 fusion, validated by reverse transcription polymerase chain reaction and Sanger sequencing. This case broadens the genetic spectrum of high-grade neuroepithelial tumor and suggests that BEND2 alterations may serve as critical determinants for this EWSR1::BEND2 glioma subgroup within the methylation classifier.

Diffuse pediatric-type high-grade gliomas (pedHGG), H3- and IDH-wildtype, encompass three main DNA-methylation-based subtypes: pedHGG-MYCN, pedHGG-RTK1A/B/C, and pedHGG-RTK2A/B. Since their first description in 2017 tumors of pedHGG-RTK2A/B have not been comprehensively characterized and clinical correlates remain elusive. In a recent series of pedHGG with a Gliomatosis cerebri (GC) growth pattern, an increased incidence of pedHGG-RTK2A/B (n = 18) was observed. We added 14 epigenetically defined pedHGG-RTK2A/B tumors to this GC series and provided centrally reviewed radiological, histological, and molecular characterization. The final cohort of 32 pedHGG-RTK2A/B tumors consisted of 25 pedHGG-RTK2A (78%) and seven pedHGG-RTK2B (22%) cases. The median age was 11.6 years (range, 4-17) with a median overall survival of 16.0 months (range 10.9-28.2). Seven of 11 of the newly added cases with imaging available showed a GC phenotype at diagnosis or follow-up. PedHGG-RTK2B tumors exhibited frequent bithalamic involvement (6/7, 86%). Central neuropathology review confirmed a diffuse glial neoplasm in all tumors with prominent angiocentric features in both subclasses. Most tumors (24/27 with available data, 89%) diffusely expressed EGFR with focal angiocentric enhancement. PedHGG-RTK2A tumors lacked OLIG2 expression, whereas 43% (3/7) of pedHGG-RTK2B expressed this glial transcription factor. ATRX loss occurred in 3/6 pedHGG-RTK2B samples with available data (50%). DNA sequencing (pedHGG-RTK2A: n = 18, pedHGG-RTK2B: n = 5) found EGFR alterations (15/23, 65%; predominantly point mutations) in both subclasses. Mutations in BCOR (14/18, 78%), SETD2 (7/18, 39%), and the hTERT promoter (7/19, 37%) occurred exclusively in pedHGG-RTK2A tumors, while pedHGG-RTK2B tumors were enriched for TP53 alterations (4/5, 80%). In conclusion, pedHGG-RTK2A/B tumors are characterized by highly diffuse-infiltrating growth patterns and specific radiological and histo-molecular features. By comprehensively characterizing methylation-based tumors, the chance to develop specific and effective therapy concepts for these detrimental tumors increases.

The gold standard for precise diagnostic classification of brain tumors requires tissue sampling, which carries relevant procedural risks. Brain biopsies often have limited sensitivity and fail to address tumor heterogeneity, because small tissue parts are being examined. This study aims to explore the detection and quantification of diagnostically relevant somatic copy number aberrations (SCNAs) in cell-free DNA (cfDNA) extracted from cerebrospinal fluid (CSF) in a real-world cohort of patients with defined brain tumor subtypes. A total of 33 CSF samples were collected from 30 patients for cfDNA extraction. Shallow whole-genome sequencing was conducted on CSF samples containing > 3ng of cfDNA and corresponding tissue DNA from nine patients. The sequencing cohort encompassed 26 samples of 23 patients, comprising 12 with confirmed CNS cancer as compared to 11 patients with either ambiguous CNS lesions (n = 5) or non-cancer CNS lesions (n = 6). After mapping and quality filtering SCNAs were called by depth-of-coverage analyses with a binning of 5.5 Mbp. SCNAs were exclusively identified in CSF cfDNA from brain tumor patients (10/12, 83%). In tumor patients, SCNAs were detectable in cfDNA from all patients with, but also in five of seven patients without tumor cells detected by CSF cytopathology. A substantial number of shared SCNAs were traceable between tissue and CSF in matched pair analyses. Additionally, some SCNAs unique to either CSF or tissue indicating spatial heterogeneity or tumor evolution. Also, diagnostically relevant genomic alterations as well as essential and desirable SCNAs as implemented in the current WHO classification of CNS tumors for certain primary brain tumor subtypes were traceable. In summary, this minimally invasive cfDNA-based LB approach employing shallow whole genome sequencing demonstrates potential for providing a molecularly informed diagnosis of CNS cancers, mapping tumor heterogeneity, tracking tumor evolution, and surveilling tumor patients. Further prospective trials are warranted.

The ability to derive retinal ganglion cells (RGCs) from human pluripotent stem cells (hPSCs) has led to numerous advances in the field of retinal research, with great potential for the use of hPSC-derived RGCs for studies of human retinal development, in vitro disease modeling, drug discovery, as well as their potential use for cell replacement therapeutics. Of all these possibilities, the use of hPSC-derived RGCs as a human-relevant platform for in vitro disease modeling has received the greatest attention, due to the translational relevance as well as the immediacy with which results may be obtained compared to more complex applications like cell replacement. While several studies to date have focused upon the use of hPSC-derived RGCs with genetic variants associated with glaucoma or other optic neuropathies, many of these have largely described cellular phenotypes with only limited advancement into exploring dysfunctional cellular pathways as a consequence of the disease-associated gene variants. Thus, to further advance this field of research, in the current study we leveraged an isogenic hPSC model with a glaucoma-associated mutation in the Optineurin (OPTN) protein, which plays a prominent role in autophagy. We identified an impairment of autophagic-lysosomal degradation and decreased mTORC1 signaling via activation of the stress sensor AMPK, along with subsequent neurodegeneration in OPTN(E50K) RGCs differentiated from hPSCs, and have further validated some of these findings in a mouse model of ocular hypertension. Pharmacological inhibition of mTORC1 in hPSC-derived RGCs recapitulated disease-related neurodegenerative phenotypes in otherwise healthy RGCs, while the mTOR-independent induction of autophagy reduced protein accumulation and restored neurite outgrowth in diseased OPTN(E50K) RGCs. Taken together, these results highlighted that autophagy disruption resulted in increased autophagic demand which was associated with downregulated signaling through mTORC1, contributing to the degeneration of RGCs.

Huntington's disease (HD) is an autosomal dominant neurodegenerative disease with a fatal outcome. There is accumulating evidence of a prominent role of glia in the pathology of HD, and we investigated this by conducting single nuclear RNA sequencing (snRNAseq) of human post mortem brain in four differentially affected regions; caudate nucleus, frontal cortex, hippocampus and cerebellum. Across 127,205 nuclei from donors with HD and age/sex matched controls, we found heterogeneity of glia which is altered in HD. We describe prominent changes in the abundance of certain subtypes of astrocytes, microglia, oligodendrocyte precursor cells and oligodendrocytes between HD and control samples, and these differences are widespread across brain regions. Furthermore, we highlight possible mechanisms that characterise the glial contribution to HD pathology including depletion of myelinating oligodendrocytes, an oligodendrocyte-specific upregulation of the calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1 A (PDE1A) and an upregulation of molecular chaperones as a cross-glial signature and a potential adaptive response to the accumulation of mutant huntingtin (mHTT). Our results support the hypothesis that glia have an important role in the pathology of HD, and show that all types of glia are affected in the disease.

The recently discovered interaction between presenilin 1 (PS1), a subunit of γ-secretase involved in amyloid-β (Aβ) peptide production, and GLT-1, the major brain glutamate transporter (EAAT2 in the human), may link two pathological aspects of Alzheimer's disease: abnormal Aβ occurrence and neuronal network hyperactivity. In the current study, we employed a FRET-based fluorescence lifetime imaging microscopy (FLIM) to characterize the PS1/GLT-1 interaction in brain tissue from sporadic AD (sAD) patients. sAD brains showed significantly less PS1/GLT-1 interaction than those with frontotemporal lobar degeneration or non-demented controls. Familial AD (fAD) PS1 mutations, inducing a "closed" PS1 conformation similar to that in sAD brain, and gamma-secretase modulators (GSMs), inducing a "relaxed" conformation, respectively reduced and increased the interaction. Furthermore, PS1 influences GLT-1 cell surface expression and homomultimer formation, acting as a chaperone but not affecting GLT-1 stability. The diminished PS1/GLT-1 interaction suggests that these functions may not work properly in AD.

Seeding activities of disease-associated α-synuclein aggregates (αSyn), a hallmark of Parkinson's disease (PD), are detectable by seed amplification assay (αSyn-SAA) and being developed as a diagnostic biomarker for PD. Sensitive and accurate αSyn-SAA for blood or saliva would greatly facilitate PD diagnosis. This prospective diagnostic study conducted αSyn-SAA analyses on serum and saliva samples collected from patients clinically diagnosed with PD or healthy controls (HC). 124 subjects (82 PD, 42 HC) donated blood and had extensive clinical assessments, of whom 74 subjects (48 PD, 26 HC) also donated saliva at the same visits. An additional 57 subjects (35 PD, 22 HC) donated saliva and had more limited clinical assessments. The mean ages were 69.21, 66.55, 69.58, and 64.71 years for PD serum donors, HC serum donors, PD saliva donors, and HC saliva donors, respectively. αSyn seeding activities in either sample type alone or both sample types together were evaluated for PD diagnosis. Serum αSyn-SAA data from 124 subjects showed 80.49% sensitivity, 90.48% specificity, and 0.9006 accuracy (AUC of ROC); saliva αSyn-SAA data from 131 subjects attained 74.70% sensitivity, 97.92% specificity, and 0.8966 accuracy. Remarkably, the combined serum and saliva αSyn-SAA from 74 subjects with both sample types achieved better diagnostic performance: 95.83% sensitivity, 96.15% specificity, and 0.98 accuracy. In addition, serum αSyn seeding activities correlated inversely with Montreal Cognitive Assessment in males and positively with Hamilton Depression Rating Scale in females and in the < 70 age group, whereas saliva αSyn seeding activities correlated inversely with age at diagnosis in males and in the < 70 age group. Our data indicate that serum and saliva αSyn-SAA together can achieve high diagnostic accuracy for PD comparable to that of CSF αSyn-SAA, suggesting their potential utility for highly sensitive, accurate, and minimally invasive diagnosis of PD in routine clinical practice and clinical studies.

The water channel aquaporin-4 (AQP4) is crucial for water balance in the mammalian brain. AQP4 has two main canonical isoforms, M23, which forms supramolecular structures called Orthogonal Arrays of Particles (OAP) and M1, which does not, along with two extended isoforms (M23ex and M1ex). This study examines these isoforms' roles, particularly AQP4ex, which influences water channel activity and localization at the blood-brain barrier. Using mice lacking both AQP4ex isoforms (AQP4ex-KO) and lacking both AQP4M23 isoforms (OAP-null) mice, we explored brain water dynamics under osmotic stress induced by an acute water intoxication (AWI) model. AQP4ex-KO mice had lower basal brain water content than WT and OAP-null mice. During AWI, brain water content increased rapidly in WT and AQP4ex-KO mice, but was delayed in OAP-null mice. AQP4ex-KO mice had the highest water content increase at 20 min. Immunoblot analysis showed stable total AQP4 in WT mice initially, with increases at 30 min. AQP4ex and its phosphorylated form (p-AQP4ex) levels rose quickly, but the p-AQP4ex/AQP4ex ratio dropped at 20 min. AQP4ex-KO mice showed a compensatory rise in canonical AQP4 at 20 min post-AWI. These findings highlight the important role of AQP4ex in water content dynamics in both normal and pathological states. To evaluate brain waste clearance, amyloid-β (Aβ) removal was assessed using a fluorescent Aβ intra-parenchyma injection model. AQP4ex-KO mice demonstrated markedly impaired Aβ clearance, with extended diffusion distances and reduced fluorescence in cervical lymph nodes, indicating inefficient drainage from the brain parenchyma. Mechanistically, the polarization of AQP4 at astrocytic endfeet is essential for efficient clearance flow, aiding interstitial fluid movement into the CSF and lymphatic system. In AQP4ex-KO mice, disrupted polarization forces reliance on slower, passive diffusion for solute clearance, significantly reducing Aβ removal efficiency and altering extracellular space dynamics. Our results underscore the importance of AQP4ex in both brain water homeostasis and solute clearance, particularly Aβ. These findings highlight AQP4ex as a potential therapeutic target for enhancing waste clearance mechanisms in the brain, which could have significant implications for treating brain edema and neurodegenerative diseases like Alzheimer's.

Valosin-containing protein (VCP) is a ubiquitously expressed type II AAA ATPase protein, implicated in both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). This study aimed to explore the impact of the disease-causing VCP mutation on mitochondrial function using a CRISPR/Cas9-engineered neuroblastoma cell line. Mitochondria in these cells are enlarged, with a depolarized mitochondrial membrane potential associated with increased respiration and electron transport chain activity. Our results indicate that mitochondrial hypermetabolism could be caused, at least partially, by increased calcium-induced opening of the permeability transition pore (mPTP), leading to mild mitochondrial uncoupling. In conclusion, our findings reveal a central role of the ALS/FTD gene VCP in maintaining mitochondrial homeostasis and suggest a model of pathogenesis based on progressive alterations in mPTP physiology and mitochondrial energetics.

A scalable platform for cell typing in the glioma microenvironment can improve tumor subtyping and immune landscape detection as successful immunotherapy strategies continue to be sought and evaluated. DNA methylation (DNAm) biomarkers for molecular classification of tumor subtypes have been developed for clinical use. However, tools that predict the cellular landscape of the tumor are not well-defined or readily available. We developed the Glioma Immune Microenvironment Composition Calculator (GIMiCC), an approach for deconvolution of cell types in gliomas using DNAm data. Using data from 17 isolated cell types, we describe the derivation of the deconvolution libraries in the biological context of selected genomic regions and validate deconvolution results using independent datasets. We utilize GIMiCC to illustrate that DNAm-based estimates of immune composition are clinically relevant and scalable for potential clinical implementation. In addition, we utilize GIMiCC to identify composition-independent DNAm alterations that are associated with high immune infiltration. Our future work aims to optimize GIMiCC and advance the clinical evaluation of glioma.

NF1 inactivation is associated with sensitivity to MEK inhibitor targeted therapy in low-grade and some high-grade gliomas. NF1 loss may also be a harbinger of exploitable vulnerabilities in IDH-wildtype glioblastoma (GBM). Accurate and consistent detection of NF1 loss, however, is fraught given the large gene size, challenges with complete coverage and variant calling upon sequencing, and mechanisms of mRNA and protein regulation that result in early degradation in the absence of genomic alterations. Here, we seek to perform a composite analysis for NF1 loss accounting for genomic alterations and protein expression via immunohistochemistry. We also characterize the landscape of NF1 alterations in GBM.

Tauopathies, including Alzheimer's disease (AD), are a class of neurodegenerative diseases characterized by the presence of insoluble tau inclusions. Tau phosphorylation has traditionally been viewed as the dominant post-translational modification (PTM) controlling tau function and pathogenesis in tauopathies. However, we and others have identified tau acetylation as a primary PTM regulating both normal tau function as well as abnormal pathogenic features including aggregation. Prior work showed robust tau acetylation in aggregation hotspots located within the 2nd and 3rd repeat regions of tau (residues K280 and K311) in tauopathy brains, including AD, compared to non-tauopathy controls. By screening thousands of hybridoma clones, we generated site-specific and modification-specific monoclonal antibodies targeting acetylated tau at residues K280 or K311. To validate these antibodies in a bona fide neuronal system, we targeted the acetyltransferase CBP to the cytoplasm of neurons to promote tau acetylation. Several antibody clones specifically detected CBP-acetylated tau and co-localized with ac-tau in neurons. Additionally, our lead optimal anti-acetylated-tau monoclonal antibodies detected robust tau pathology in tangles and neuritic plaques of human AD brains. Given the now emerging interest in acetylated tau as critical regulator of tau functions, these sensitive and highly specific tools will allow us to further unravel the tau PTM code and, importantly, could be deployed as diagnostic or disease-modifying agents.

Monitoring tumor evolution and predicting survival using non-invasive liquid biopsy is an unmet need for glioblastoma patients. The era of proteomics and metabolomics blood analyzes, may help in this context. A case-control study was conducted. Patients were included in the GLIOPLAK trial (ClinicalTrials.gov Identifier: NCT02617745), a prospective bicentric study conducted between November 2015 and December 2022. Patients underwent biopsy alone and received radiotherapy and temozolomide. Blood samples were collected at three different time points: before and after concomitant radiochemotherapy, and at the time of tumor progression. Plasma samples from patients and controls were analyzed using metabolomics and proteomics, generating 371 omics features. Descriptive, differential, and predictive analyses were performed to assess the relationship between plasma omics feature levels and patient outcome. Diagnostic performance and longitudinal variations were also analyzed. The study included 67 subjects (34 patients and 33 controls). A significant differential expression of metabolites and proteins between patients and controls was observed. Predictive models using omics features showed high accuracy in distinguishing patients from controls. Longitudinal analysis revealed temporal variations in a few omics features including CD22, CXCL13, EGF, IL6, GZMH, KLK4, and TNFRSP6B. Survival analysis identified 77 omics features significantly associated with OS, with ERBB2 and ITGAV consistently linked to OS at all timepoints. Pathway analysis revealed dynamic oncogenic pathways involved in glioblastoma progression. This study provides insights into the potential of plasma omics features as biomarkers for glioblastoma diagnosis, progression and overall survival. Clinical implication should now be explored in dedicated prospective trials.

Protein aggregate myopathies can result from pathogenic variants in genes encoding protein chaperones. DNAJB4 is a cochaperone belonging to the heat shock protein-40 (HSP40) family and plays a vital role in cellular proteostasis. Recessive loss-of-function variants in DNAJB4 cause myopathy with early respiratory failure and spinal rigidity, presenting from infancy to adulthood. This study investigated the broader clinical and genetic spectrum of DNAJB4 myopathy. In this study, we performed whole-exome sequencing on seven patients with early respiratory failure of unknown genetic etiology. We identified five distinct pathogenic variants in DNAJB4 in five unrelated families of diverse ethnic backgrounds: three loss-of-function variants (c.547 C > T, p.R183*; c.775 C > T, p.R259*; an exon 2 deletion) and two missense variants (c.105G > C, p.K35N; c.181 A > G, p.R61G). All patients were homozygous. Most affected individuals exhibited early respiratory failure, and patients from three families had rigid spine syndrome with axial weakness in proportion to appendicular weakness. Additional symptoms included dysphagia, ankle contractures, scoliosis, neck stiffness, and cardiac dysfunction. Notably, J-domain missense variants were associated with a more severe phenotype, including an earlier age of onset and a higher mortality rate, suggesting a strong genotype‒phenotype correlation. Consistent with a loss of function, the nonsense variants presented decreased stability. In contrast, the missense variants exhibited normal or increased stability but behaved as loss-of-function variants in yeast complementation and TDP-43 disaggregation assays. Our findings suggest that DNAJB4 is an emerging cause of myopathy with rigid spine syndrome of variable age of onset and severity. This diagnosis should be considered in individuals presenting with suggestive symptoms, particularly if they exhibit neck stiffness during infancy or experience respiratory failure in adults without significant limb muscle weakness. Missense variants in the J domain may predict a more severe phenotype.

Multiple sclerosis (MS) is a complex chronic neuroinflammatory disease characterized by demyelination leading to neuronal dysfunction and neurodegeneration manifested by various neurological impairments. The endocannabinoid system (ECS) is a lipid signalling network, which plays multiple roles in the central nervous system and the periphery, including synaptic signal transmission and modulation of inflammation. The ECS has been identified as a potential target for the development of novel therapeutic interventions in MS patients. It remains unclear whether ECS-associated metabolites are changed in MS and could serve as biomarkers in blood or cerebrospinal fluid (CSF). In this retrospective study we applied targeted lipidomics to matching CSF and serum samples of 74 MS and 80 non-neuroinflammatory control patients. We found that MS-associated lipidomic changes overall did not coincide between CSF and serum. While glucocorticoids correlated positively, only the endocannabinoid (eCB) 2-arachidonoyl glycerol (2-AG) showed a weak positive correlation (r = 0.3, p < 0.05) between CSF and serum. Peptide endocannabinoids could be quantified for the first time in CSF but did not differ between MS and controls. MS patients showed elevated levels of prostaglandin E2 and steaorylethanolamide in serum, and 2-oleoylglycerol and cortisol in CSF. Sex-specific differences were found in CSF of MS patients showing increased levels of 2-AG and glucocorticoids in males only. Overall, arachidonic acid was elevated in CSF of males. Interestingly, CSF eCBs correlated positively with age only in the control patients due to the increased levels of eCBs in young relapsing-remitting MS patients. Our findings reveal significant discrepancies between CSF and serum, underscoring that measuring eCBs in blood matrices is not optimal for detecting MS-associated changes in the central nervous system. The identified sex and age-specific changes of analytes of the stress axis and ECS specifically in the CSF of MS patients supports the role of the ECS in MS and may be relevant for drug development strategies.

Mutations in the isocitrate dehydrogenase (IDH) gene are recognized as the key drivers in the oncogenesis of astrocytoma and oligodendroglioma. However, the significance of IDH mutation in tumor maintenance and malignant transformation has not been elucidated. We encountered a unique case of IDH-mutant astrocytoma that, upon malignant transformation, presented two distinct intratumoral components: one IDH-wildtype and one IDH-mutant. The IDH-wild-type component exhibited histological findings similar to those of small cell-type glioblastoma with a higher Ki-67 index than the IDH-mutant component. Despite their genetic divergence, both components exhibited similar comprehensive methylation profiles within the CpG island and were classified into methylation class of "Astrocytoma, IDH-mutant; High Grade" by the German Cancer Center (DKFZ) classifier v11.4. Phylogenetic analysis demonstrated that the IDH-wildtype component emerged as a subclonal component of the primary tumor. Detailed molecular analyses revealed that the loss of the IDH mutation was induced by the hemizygous loss of the entire arm of chromosome 2, on which IDH1 gene is located. Notably, the IDH-wild-type subclones uniquely acquired CDKN2A/B homozygous deletion and PDGFRA amplification, which is a marker of the aggressive phenotype of astrocytoma, IDH-mutant. Because these genetic abnormalities can drive oncogenic pathways, such as the PI3K/AKT/mTOR and RB signaling pathway, IDH-mutant gliomas that acquired these mutations were no longer dependent on the initial driver mutation, the IDH mutation. Molecular analysis of this unique case provides insight that in a subset of astrocytoma, IDH-mutant that acquired these genetic abnormalities, IDH mutation may not play a pivotal role in tumor growth and acquisition of these genetic abnormalities may contribute to the acquisition of resistance to IDH inhibitors.