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Tumors growing in metabolically challenged environments, such as glioblastoma in the brain, are particularly reliant on crosstalk with their tumor microenvironment (TME) to satisfy their high energetic needs. To study the intricacies of this metabolic interplay, we interrogated the heterogeneity of the glioblastoma TME using single-cell and multi-omics analyses and identified metabolically rewired tumor-associated macrophage (TAM) subpopulations with pro-tumorigenic properties. These TAM subsets, termed lipid-laden macrophages (LLMs) to reflect their cholesterol accumulation, are epigenetically rewired, display immunosuppressive features, and are enriched in the aggressive mesenchymal glioblastoma subtype. Engulfment of cholesterol-rich myelin debris endows subsets of TAMs to acquire an LLM phenotype. Subsequently, LLMs directly transfer myelin-derived lipids to cancer cells in an LXR/Abca1-dependent manner, thereby fueling the heightened metabolic demands of mesenchymal glioblastoma. Our work provides an in-depth understanding of the immune-metabolic interplay during glioblastoma progression, thereby laying a framework to unveil targetable metabolic vulnerabilities in glioblastoma.
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Single-cell technologies have enabled the characterization of the tumour microenvironment at unprecedented depth and have revealed vast cellular diversity among tumour cells and their niche. Anti-tumour immunity relies on cell-cell relationships within the tumour microenvironment1,2, yet many single-cell studies lack spatial context and rely on dissociated tissues3. Here we applied imaging mass cytometry to characterize the immunological landscape of 139 high-grade glioma and 46 brain metastasis tumours from patients. Single-cell analysis of more than 1.1 million cells across 389 high-dimensional histopathology images enabled the spatial resolution of immune lineages and activation states, revealing differences in immune landscapes between primary tumours and brain metastases from diverse solid cancers. These analyses revealed cellular neighbourhoods associated with survival in patients with glioblastoma, which we leveraged to identify a unique population of myeloperoxidase (MPO)-positive macrophages associated with long-term survival. Our findings provide insight into the biology of primary and metastatic brain tumours, reinforcing the value of integrating spatial resolution to single-cell datasets to dissect the microenvironmental contexture of cancer.
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Neoplasias Encefálicas , Glioma , Análise de Célula Única , Microambiente Tumoral , Humanos , Encéfalo/imunologia , Encéfalo/patologia , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/secundário , Glioblastoma/imunologia , Glioblastoma/patologia , Glioma/imunologia , Glioma/patologia , Macrófagos/enzimologia , Microambiente Tumoral/imunologia , Metástase Neoplásica , Conjuntos de Dados como AssuntoRESUMO
Multiple sclerosis is a chronic inflammatory disease of the CNS1. Astrocytes contribute to the pathogenesis of multiple sclerosis2, but little is known about the heterogeneity of astrocytes and its regulation. Here we report the analysis of astrocytes in multiple sclerosis and its preclinical model experimental autoimmune encephalomyelitis (EAE) by single-cell RNA sequencing in combination with cell-specific Ribotag RNA profiling, assay for transposase-accessible chromatin with sequencing (ATAC-seq), chromatin immunoprecipitation with sequencing (ChIP-seq), genome-wide analysis of DNA methylation and in vivo CRISPR-Cas9-based genetic perturbations. We identified astrocytes in EAE and multiple sclerosis that were characterized by decreased expression of NRF2 and increased expression of MAFG, which cooperates with MAT2α to promote DNA methylation and represses antioxidant and anti-inflammatory transcriptional programs. Granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling in astrocytes drives the expression of MAFG and MAT2α and pro-inflammatory transcriptional modules, contributing to CNS pathology in EAE and, potentially, multiple sclerosis. Our results identify candidate therapeutic targets in multiple sclerosis.
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Astrócitos/patologia , Sistema Nervoso Central/patologia , Inflamação/patologia , Fator de Transcrição MafG/genética , Proteínas Repressoras/genética , Animais , Antioxidantes/metabolismo , Astrócitos/metabolismo , Sistema Nervoso Central/metabolismo , Metilação de DNA , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/patologia , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Inflamação/genética , Masculino , Metionina Adenosiltransferase/genética , Camundongos , Esclerose Múltipla/genética , Esclerose Múltipla/patologia , Fator 2 Relacionado a NF-E2/genética , Análise de Sequência de RNA , Transdução de Sinais , Transcrição GênicaRESUMO
Raman spectroscopy imaging is a technique that can be adapted for intraoperative tissue characterization to be used for surgical guidance. Here we present a macroscopic line scanning Raman imaging system that has been modified to ensure suitability for intraoperative use. The imaging system has a field of view of 1 × 1 cm2 and acquires Raman fingerprint images of 40 × 42 pixels, typically in less than 5 minutes. The system is mounted on a mobile cart, it is equiped with a passive support arm and possesses a removable and sterilizable probe muzzle. The results of a proof of concept study are presented in porcine adipose and muscle tissue. Supervised machine learning models (support vector machines and random forests) were trained and they were tested on a holdout dataset consisting of 7 Raman images (10 080 spectra) acquired in different animal tissues. This led to a detection accuracy >96% and prediction confidence maps providing a quantitative detection assessment for tissue border visualization. Further testing was accomplished on a dataset acquired with the imaging probe's contact muzzle and tailored classification models showed robust classifications capabilities with specificity, sensitivity and accuracy all surpassing 95% with a support vector machine classifier. Finally, laser safety, biosafety and sterilization of the system was assest. The safety assessment showed that the system's laser can be operated safetly according to the American National Standards Institute's standard for maximum permissible exposures for eyes and skin. It was further shown that during tissue interrogation, the temperature-history in cumulative equivalent minutes at 43 °C (CEM43 °C) never exceeded a safe threshold of 5 min.
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Período Intraoperatório , Análise Espectral Raman , Análise Espectral Raman/instrumentação , Análise Espectral Raman/métodos , Suínos , Animais , Tecido Adiposo , Músculo EsqueléticoRESUMO
Morphological and emerging molecular studies have provided evidence for heterogeneity within the oligodendrocyte population. To address the regional and age-related heterogeneity of human mature oligodendrocytes (MOLs) we applied single-cell RNA sequencing to cells isolated from cortical/subcortical, subventricular zone brain tissue samples, and thoracolumbar spinal cord samples. Unsupervised clustering of cells identified transcriptionally distinct MOL subpopulations across regions. Spinal cord MOLs, but not microglia, exhibited cell-type-specific upregulation of immune-related markers compared to the other adult regions. SVZ MOLs showed an upregulation of select number of development-linked transcription factors compared to other regions; however, pseudotime trajectory analyses did not identify a global developmental difference. Age-related analysis of cortical/subcortical samples indicated that pediatric MOLs, especially from under age 5, retain higher expression of genes linked to development and to immune activity with pseudotime analysis favoring a distinct developmental stage. Our regional and age-related studies indicate heterogeneity of MOL populations in the human CNS that may reflect developmental and environmental influences.
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Oligodendroglia , Medula Espinal , Encéfalo , Criança , Pré-Escolar , Humanos , Microglia , Oligodendroglia/metabolismoRESUMO
Characterizing the developmental trajectory of oligodendrocyte progenitor cells (OPC) is of great interest given the importance of these cells in the remyelination process. However, studies of human OPC development remain limited by the availability of whole cell samples and material that encompasses a wide age range, including time of peak myelination. In this study, we apply single cell RNA sequencing to viable whole cells across the age span and link transcriptomic signatures of oligodendrocyte-lineage cells with stage-specific functional properties. Cells were isolated from surgical tissue samples of second-trimester fetal, 2-year-old pediatric, 13-year-old adolescent, and adult donors by mechanical and enzymatic digestion, followed by percoll gradient centrifugation. Gene expression was analyzed using droplet-based RNA sequencing (10X Chromium). Louvain clustering analysis identified three distinct cellular subpopulations based on 5,613 genes, comprised of an early OPC (e-OPC) group, a late OPC group (l-OPC), and a mature OL (MOL) group. Gene ontology terms enriched for e-OPCs included cell cycle and development, for l-OPCs included extracellular matrix and cell adhesion, and for MOLs included myelination and cytoskeleton. The e-OPCs were mostly confined to the premyelinating fetal group, and the l-OPCs were most highly represented in the pediatric age group, corresponding to the peak age of myelination. Cells expressing a signature characteristic of l-OPCs were identified in the adult brain in situ using RNAScope. These findings highlight the transcriptomic variability in OL-lineage cells before, during, and after peak myelination and contribute to identifying novel pathways required to achieve remyelination.
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Diferenciação Celular/fisiologia , Células Precursoras de Oligodendrócitos/citologia , Oligodendroglia/citologia , Células-Tronco/citologia , Adolescente , Encéfalo/diagnóstico por imagem , Encéfalo/crescimento & desenvolvimento , Células Cultivadas , Humanos , Bainha de Mielina/classificação , Bainha de Mielina/metabolismo , Oligodendroglia/metabolismo , Análise de Sequência de RNA/métodos , Células-Tronco/metabolismoAssuntos
Camptotecina , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Receptor ErbB-2 , Trastuzumab , Humanos , Trastuzumab/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Receptor ErbB-2/metabolismo , Camptotecina/análogos & derivados , Camptotecina/uso terapêutico , Imunoconjugados/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Feminino , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genéticaRESUMO
Raman spectroscopy is a promising tool for neurosurgical guidance and cancer research. Quantitative analysis of the Raman signal from living tissues is, however, limited. Their molecular composition is convoluted and influenced by clinical factors, and access to data is limited. To ensure acceptance of this technology by clinicians and cancer scientists, we need to adapt the analytical methods to more closely model the Raman-generating process. Our objective is to use feature engineering to develop a new representation for spectral data specifically tailored for brain diagnosis that improves interpretability of the Raman signal while retaining enough information to accurately predict tissue content. The method consists of band fitting of Raman bands which consistently appear in the brain Raman literature, and the generation of new features representing the pairwise interaction between bands and the interaction between bands and patient age. Our technique was applied to a dataset of 547 in situ Raman spectra from 65 patients undergoing glioma resection. It showed superior predictive capacities to a principal component analysis dimensionality reduction. After analysis through a Bayesian framework, we were able to identify the oncogenic processes that characterize glioma: increased nucleic acid content, overexpression of type IV collagen and shift in the primary metabolic engine. Our results demonstrate how this mathematical transformation of the Raman signal allows the first biological, statistically robust analysis of in vivo Raman spectra from brain tissue.
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Neoplasias Encefálicas/metabolismo , Glioma/metabolismo , Análise Espectral Raman/métodos , Teorema de Bayes , Neoplasias Encefálicas/química , Colágeno Tipo IV/metabolismo , Conjuntos de Dados como Assunto , Feminino , Glioma/química , Humanos , Cuidados Intraoperatórios , Luz , Masculino , Pessoa de Meia-Idade , Ácidos Nucleicos/metabolismo , Análise de Componente Principal , Estudos RetrospectivosRESUMO
Triple-negative breast cancer (TNBC) is typically aggressive, difficult to treat, and commonly metastasizes to the visceral organs and soft tissues, including the lungs and the brain. Taxanes represent the most effective and widely used therapeutic class in metastatic TNBC but possess limiting adverse effects that often result in a delay, reduction, or cessation of their use. DZ-2384 is a candidate microtubule-targeting agent with a distinct mechanism of action and strong activity in several preclinical cancer models, with reduced toxicities. DZ-2384 is highly effective in patient-derived taxane-sensitive and taxane-resistant xenograft models of TNBC at lower doses and over a wider range relative to paclitaxel. When comparing compound exposure at minimum effective doses relative to safe exposure levels, the therapeutic window for DZ-2384 is 14-32 compared with 2.0 and less than 2.8 for paclitaxel and docetaxel, respectively. DZ-2384 is effective at reducing brain metastatic lesions when used at maximum tolerated doses and is equivalent to paclitaxel. Drug distribution experiments indicate that DZ-2384 is taken up more efficiently by tumor tissue but at equivalent levels in the brain compared with paclitaxel. Selective DZ-2384 uptake by tumor tissue may in part account for its wider therapeutic window compared with taxanes. In view of the current clinical efforts to combine chemotherapy with immune checkpoint inhibitors, we demonstrate that DZ-2384 acts synergistically with anti-CTLA-4 immunotherapy in a syngeneic murine model. These results demonstrate that DZ-2384 has a superior pharmacologic profile over currently used taxanes and is a promising therapeutic agent for the treatment of metastatic TNBC.
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Antineoplásicos Imunológicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Antígeno CTLA-4/antagonistas & inibidores , Lactamas Macrocíclicas/farmacologia , Oxazóis/farmacologia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos Imunológicos/administração & dosagem , Encéfalo/metabolismo , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Sinergismo Farmacológico , Feminino , Humanos , Lactamas Macrocíclicas/administração & dosagem , Lactamas Macrocíclicas/farmacocinética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Camundongos SCID , Metástase Neoplásica , Oxazóis/administração & dosagem , Oxazóis/farmacocinética , Distribuição Aleatória , Neoplasias de Mama Triplo Negativas/imunologia , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Ambient light artifacts can confound Raman spectroscopy measurements performed in a clinical setting such as during open surgery. However, requiring light sources to be turned off during intraoperative spectral acquisition can be impractical because it can slow down the procedure by requiring surgeons to acquire data under light conditions different from the routine clinical practice. Here a filter system is introduced allowing in vivo Raman spectroscopy measurements to be performed with the light source of a neurosurgical microscope turned on, without interfering with the standard procedure. Ex vivo and in vivo results on calf and human brain, respectively, show that when the new filter system is used there is no significant difference between Raman spectra acquired under pitch dark conditions or with the microscope light source turned on. This is important for the clinical translation of Raman spectroscopy because of the resulting decrease in total imaging time for each measurement and because the surgeon can now acquire spectroscopic data with no disruption of the surgical workflow.
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Confiabilidade dos Dados , Microcirurgia , Análise Espectral Raman , Artefatos , Humanos , IluminaçãoRESUMO
BACKGROUND: Decompressive hemicraniectomy (DhC) is a life-saving surgical procedure being increasingly employed for malignant middle cerebral artery strokes. We examined the incidence of hemorrhagic transformation following DhC. METHODS: We retrospectively reviewed the charts and radiological images of patients who underwent DhC for malignant middle cerebral artery strokes. We classified the hemorrhagic events and assessed the short-term 30-day outcome associated with these events. RESULTS: A total of 23 DhCs were performed for supratentorial ischemic strokes in 22 patients. There were 16 males and 6 females with an average age of 47 years (21-69 years). Of the 22 patients, 13 (59%) developed a new hemorrhage following DhC. There were 3 mortalities (14%). Of the survivors, 6 (27%) were discharged home with a modified Rankin Scale (mRS) score of 2. The remaining 13 patients (59%) recovered to a degree wherein they were discharged to a rehabilitation center (mRS score 3-4). No patient persisted in a vegetative or semivegetative state (mRS score 5). CONCLUSIONS: In this study, the rate of hemorrhagic transformation following DhC for ischemic stroke was 59%. This is much higher than that reported in the stroke thrombolysis literature. The presence of any type of new hemorrhagic transformation in this patient population does not appear to alter the natural history of their ischemic strokes in terms of Glasgow outcome scores or destination of disposition.
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Craniectomia Descompressiva/efeitos adversos , Transtornos Hemorrágicos/etiologia , Complicações Pós-Operatórias/etiologia , Acidente Vascular Cerebral/cirurgia , Adulto , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/cirurgia , Feminino , Seguimentos , Escala de Resultado de Glasgow , Transtornos Hemorrágicos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia , Adulto JovemRESUMO
The extraction of tissue samples during brain needle biopsy can cause life-threatening hemorrhage because of significant blood vessel injury during the procedure. Vessel rupture can have significant consequences for patient health, ranging from transient neurological deficits to death. Here, we present a sub-diffuse optical tomography technique that can be integrated into neurosurgical workflow to detect the presence of blood vessels. A proof-of-concept study performed on a realistic brain tissue phantom is presented and demonstrates that interstitial optical tomography (iOT) can detect several 1 mm diameter high-contrast absorbing objects located <2 mm from the needle.
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Biópsia por Agulha/métodos , Encéfalo/patologia , Segurança , Cirurgia Assistida por Computador/métodos , Tomografia Óptica , Biópsia por Agulha/efeitos adversos , Encéfalo/irrigação sanguínea , Humanos , Imagens de Fantasmas , Cirurgia Assistida por Computador/efeitos adversosRESUMO
To determine the variability in processes of care in the last 6 months of life experienced by patients dying of primary intracranial tumors and potential predictors of place of death, a death-backwards cohort was assembled using historical data and 1,623 decedents were identified. 90 % of people had ≥ 1 admission to an acute care hospital and 23 % spent ≥ 3 months of their last 6 months of life in acute care. 44 % had ≥ 1 ER visits and 30 % were admitted ≥ 1 times to ICU. Only 18 % had a home visit by a physician. 10 % died at home but 49 % died in hospital, while 40 % died in a palliative care facility. Age, comorbidities, and being diagnosed with grade 4 astrocytoma were associated with greater burden of care. Level of care burden and age were associated with higher odds of dying in a treatment intensive place of death, being diagnosed with grade 4 astrocytoma had opposite effect. Despite valuable research efforts to improve the treatment of primary intracranial tumors that focus on biology, refinements to surgery, radiation, and chemotherapy, there is also room to improve aspects of care at the end of life situation. An integrative approach for this patients' population, from diagnosis to death, could potentially reduce the care burden in the final period on the health care system, patient's family and improve access to a better place of death.
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Neoplasias Encefálicas/terapia , Cuidados Paliativos , Assistência Terminal , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Astrocitoma/epidemiologia , Astrocitoma/patologia , Astrocitoma/terapia , Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/patologia , Estudos de Coortes , Comorbidade , Feminino , Custos de Cuidados de Saúde , Serviços de Assistência Domiciliar , Hospitais para Doentes Terminais/tendências , Hospitais , Habitação/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Padrões de Prática MédicaRESUMO
Here we introduce a Raman spectroscopy approach combining multi-spectral imaging and a new fluorescence background subtraction technique to image individual Raman peaks in less than 5 seconds over a square field-of-view of 1-centimeter sides with 350 micrometers resolution. First, human data is presented supporting the feasibility of achieving cancer detection with high sensitivity and specificity - in brain, breast, lung, and ovarian/endometrium tissue - using no more than three biochemically interpretable biomarkers associated with the inelastic scattering signal from specific Raman peaks. Second, a proof-of-principle study in biological tissue is presented demonstrating the feasibility of detecting a single Raman band - here the CH2/CH3 deformation bands from proteins and lipids - using a conventional multi-spectral imaging system in combination with the new background removal method. This study paves the way for the development of a new Raman imaging technique that is rapid, label-free, and wide field.
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The existence of neural stem cells (NSCs) in adult human brain neurogenic regions remains unresolved. To address this, we created a cell atlas of the adult human subventricular zone (SVZ) derived from fresh neurosurgical samples using single-cell transcriptomics. We discovered 2 adult radial glia (RG)-like populations, aRG1 and aRG2. aRG1 shared features with fetal early RG (eRG) and aRG2 were transcriptomically similar to fetal outer RG (oRG). We also captured early neuronal and oligodendrocytic NSC states. We found that the biological programs driven by their transcriptomes support their roles as early lineage NSCs. Finally, we show that these NSCs have the potential to transition between states and along lineage trajectories. These data reveal that multipotent NSCs reside in the adult human SVZ.
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Safe and effective brain tumor surgery aims to remove tumor tissue, not non-tumoral brain. This is a challenge since tumor cells are often not visually distinguishable from peritumoral brain during surgery. To address this, we conducted a multicenter study testing whether the Sentry System could distinguish the three most common types of brain tumors from brain tissue in a label-free manner. The Sentry System is a new real time, in situ brain tumor detection device that merges Raman spectroscopy with machine learning tissue classifiers. Nine hundred and seventy-six in situ spectroscopy measurements and colocalized tissue specimens were acquired from 67 patients undergoing surgery for glioblastoma, brain metastases, or meningioma to assess tumor classification. The device achieved diagnostic accuracies of 91% for glioblastoma, 97% for brain metastases, and 96% for meningiomas. These data show that the Sentry System discriminated tumor containing tissue from non-tumoral brain in real time and prior to resection.
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Neoplasias Encefálicas , Análise Espectral Raman , Humanos , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/cirurgia , Análise Espectral Raman/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Meningioma/diagnóstico , Meningioma/patologia , Glioblastoma/patologia , Glioblastoma/diagnóstico , Glioblastoma/cirurgia , Adulto , Aprendizado de Máquina , Encéfalo/patologia , Encéfalo/diagnóstico por imagemRESUMO
BACKGROUND: Compared to minimally invasive brain metastases (MI BrM), highly invasive (HI) lesions form abundant contacts with cells in the peritumoral brain parenchyma and are associated with poor prognosis. Reactive astrocytes (RAs) labeled by phosphorylated STAT3 (pSTAT3) have recently emerged as a promising therapeutic target for BrM. Here, we explore whether the BrM invasion pattern is influenced by pSTAT3+â RAs and may serve as a predictive biomarker for STAT3 inhibition. METHODS: We used immunohistochemistry to identify pSTAT3+ RAs in HI and MI human and patient-derived xenograft (PDX) BrM. Using PDX, syngeneic, and transgenic mouse models of HI and MI BrM, we assessed how pharmacological STAT3 inhibition or RA-specific STAT3 genetic ablation affected BrM growth in vivo. Cancer cell invasion was modeled in vitro using a brain slice-tumor co-culture assay. We performed single-cell RNA sequencing of human BrM and adjacent brain tissue. RESULTS: RAs expressing pSTAT3 are situated at the brain-tumor interface and drive BrM invasive growth. HI BrM invasion pattern was associated with delayed growth in the context of STAT3 inhibition or genetic ablation. We demonstrate that pSTAT3+ RAs secrete Chitinase 3-like-1 (CHI3L1), which is a known STAT3 transcriptional target. Furthermore, single-cell RNA sequencing identified CHI3L1-expressing RAs in human HI BrM. STAT3 activation, or recombinant CHI3L1 alone, induced cancer cell invasion into the brain parenchyma using a brain slice-tumor plug co-culture assay. CONCLUSIONS: Together, these data reveal that pSTAT3+ RA-derived CHI3L1 is associated with BrM invasion, implicating STAT3 and CHI3L1 as clinically relevant therapeutic targets for the treatment of HI BrM.
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Astrócitos , Neoplasias Encefálicas , Proteína 1 Semelhante à Quitinase-3 , Invasividade Neoplásica , Fator de Transcrição STAT3 , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Humanos , Proteína 1 Semelhante à Quitinase-3/metabolismo , Proteína 1 Semelhante à Quitinase-3/genética , Animais , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/genética , Astrócitos/metabolismo , Astrócitos/patologia , Camundongos , Camundongos Transgênicos , Proliferação de Células , Ensaios Antitumorais Modelo de Xenoenxerto , Células Tumorais CultivadasRESUMO
Reactive changes of glial cells during neuroinflammation impact brain disorders and disease progression. Elucidating the mechanisms that control reactive gliosis may help us to understand brain pathophysiology and improve outcomes. Here, we report that adult ablation of autism spectrum disorder (ASD)-associated CHD8 in astrocytes attenuates reactive gliosis via remodeling chromatin accessibility, changing gene expression. Conditional Chd8 deletion in astrocytes, but not microglia, suppresses reactive gliosis by impeding astrocyte proliferation and morphological elaboration. Astrocyte Chd8 ablation alleviates lipopolysaccharide-induced neuroinflammation and septic-associated hypothermia in mice. Astrocytic CHD8 plays an important role in neuroinflammation by altering the chromatin landscape, regulating metabolic and lipid-associated pathways, and astrocyte-microglia crosstalk. Moreover, we show that reactive gliosis can be directly mitigated in vivo using an adeno-associated virus (AAV)-mediated Chd8 gene editing strategy. These findings uncover a role of ASD-associated CHD8 in the adult brain, which may warrant future exploration of targeting chromatin remodelers in reactive gliosis and neuroinflammation in injury and neurological diseases.
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Spinocerebellar ataxia 27B (SCA27B) is a common autosomal dominant ataxia caused by an intronic GAAâ¢TTC repeat expansion in FGF14 . Neuropathological studies have shown that neuronal loss is largely restricted to the cerebellum. Although the repeat locus is highly unstable during intergenerational transmission, it remains unknown whether it exhibits cerebral mosaicism and progressive instability throughout life. We conducted an analysis of the FGF14 GAAâ¢TTC repeat somatic instability across 156 serial blood samples from 69 individuals, fibroblasts, induced pluripotent stem cells, and post-mortem brain tissues from six controls and six patients with SCA27B, alongside methylation profiling using targeted long-read sequencing. Peripheral tissues exhibited minimal somatic instability, which did not significantly change over periods of more than 20 years. In post-mortem brains, the GAAâ¢TTC repeat was remarkably stable across all regions, except in the cerebellar hemispheres and vermis. The levels of somatic expansion in the cerebellar hemispheres and vermis were, on average, 3.15 and 2.72 times greater relative to other examined brain regions, respectively. Additionally, levels of somatic expansion in the brain increased with repeat length and tissue expression of FGF14 . We found no significant difference in methylation of wild-type and expanded FGF14 alleles in post-mortem cerebellar hemispheres between patients and controls. In conclusion, our study revealed that the FGF14 GAAâ¢TTC repeat exhibits a cerebellar-specific expansion bias, which may explain the pure and late-onset cerebellar involvement in SCA27B.
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Glioblastomas (GBM) are highly motile cancers that invade through normal brain. In the absence of curative chemotherapy this invasion, beyond surgical and radiotherapy margins, to distant brain sites is thought to be an important cause of treatment failure. Paradoxically, studies analyzing failure patterns have consistently shown that the large majority of failures occur at the original tumor site. This conflict may be explained by the fact these cancers are often only sub-totally resected and radiotherapy and chemotherapies fail to control this significant local cancer burden. We analyzed the failure pattern in 20 consecutive patients with complete resection of the gadolinium-enhancing portion of GBM demonstrated on the immediate post-operative magnetic resonance study, and who underwent a radical course of radiotherapy and chemotherapy. We found that recurrences occurred only at the resection margin in 17 of 20 patients. Recurrences were exclusively distant in 2 of 20 patients and occurred at both the resection margin and a distant site in 1 of 20 cases. We found that even in cases of complete resection of the gadolinium-enhancing portion of GBM 85 % of recurrences are localized to the resection margin.