Defining tumor-associated vascular heterogeneity in pediatric high-grade and diffuse midline gliomas
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE179372 | GEO | 2021/09/01
REPOSITORIES: GEO
Similar Datasets
Project description:The neurovascular unit (NVU) is a complex multicellular structure that helps maintain cerebral homeostasis and blood-brain barrier (BBB) integrity. While extensive evidence links NVU alterations to cerebrovascular diseases and neurodegeneration, the underlying molecular mechanisms remain unclear. Here, we use zebrafish embryos carrying a mutation in Scavenger Receptor B2, a highly conserved endolysosomal protein expressed predominantly in Radial Glia Cells (RGCs), to investigate the interplay among different NVU components. Through live imaging and genetic manipulations, we demonstrate that compromised acidification of the endolysosomal compartment in mutant RGCs leads to impaired Notch3 signaling, thereby inducing excessive neurogenesis and reduced glial differentiation. We further demonstrate that alterations to the neuron/glia balance result in impaired VEGF and Wnt signaling, leading to severe vascular defects, hemorrhages, and a leaky BBB. Altogether, our findings provide novel insights into NVU formation and function and offer new avenues for investigating diseases involving white matter defects and vascular abnormalities. The neurovascular unit (NVU) is a complex multicellular structure that helps maintain cerebral homeostasis and blood-brain barrier (BBB) integrity. While extensive evidence links NVU alterations to cerebrovascular diseases and neurodegeneration, the underlying molecular mechanisms remain unclear. Here, we use zebrafish embryos carrying a mutation in Scavenger Receptor B2, a highly conserved endolysosomal protein expressed predominantly in Radial Glia Cells (RGCs), to investigate the interplay among different NVU components. Through live imaging and genetic manipulations, we demonstrate that compromised acidification of the endolysosomal compartment in mutant RGCs leads to impaired Notch3 signaling, thereby inducing excessive neurogenesis and reduced glial differentiation. We further demonstrate that alterations to the neuron/glia balance result in impaired VEGF and Wnt signaling, leading to severe vascular defects, hemorrhages, and a leaky BBB. Altogether, our findings provide novel insights into NVU formation and function and offer new avenues for investigating diseases involving white matter defects and vascular abnormalities. The neurovascular unit (NVU) is a complex multicellular structure that helps maintain cerebral homeostasis and blood-brain barrier (BBB) integrity. While extensive evidence links NVU alterations to cerebrovascular diseases and neurodegeneration, the underlying molecular mechanisms remain unclear. Here, we use zebrafish embryos carrying a mutation in Scavenger Receptor B2, a highly conserved endolysosomal protein expressed predominantly in Radial Glia Cells (RGCs), to investigate the interplay among different NVU components. Through live imaging and genetic manipulations, we demonstrate that compromised acidification of the endolysosomal compartment in mutant RGCs leads to impaired Notch3 signaling, thereby inducing excessive neurogenesis and reduced glial differentiation. We further demonstrate that alterations to the neuron/glia balance result in impaired VEGF and Wnt signaling, leading to severe vascular defects, hemorrhages, and a leaky BBB. Altogether, our findings provide novel insights into NVU formation and function and offer new avenues for investigating diseases involving white matter defects and vascular abnormalities.
2024-09-01 | GSE270309 | GEO
Project description:Diffuse midline glioma (DMG) is a uniformly fatal pediatric, adolescent, and young adult cancer diagnosed in the midline structures of the brain. PI3K/Akt signaling is an overarching contributor to the poor outcomes of DMG patients due to their dependance on insulin and recurring mutations and amplifications in PI3K/Akt genes. Paxalisib (GDC-0084) is a potent PI3K/Akt inhibitor developed to penetrate the brain’s protective blood-brain barrier (BBB). We performed paxalisib regimen optimization by assessment of blood glucose levels, analysis in vivo pharmacokinetics/pharmacodynamics properties, and employed DMG patient derived xenograft (PDX) mouse models to determine preclinical efficacy. To identify novel combination strategies, we conducted high-resolution quantitative phosphoproteomics of DMG cells treated with paxalisib. Elevated blood glucose levels promoting hyperglycemia was seen in mice using paxalisib 10 mg/kg/day (~mouse equivalent human maximum tolerated dose- NCT03696355). Whereas 5 mg/kg/day, or 5mg/kg/b.i.d. (twice daily) non-significantly increased blood glucose levels compared to controls. Pharmacokinetic analysis of mouse tissues showed 5 mg/kg/b.i.d. increased paxalisib acumination in the brainstem, suppressing PI3K/Akt signaling to significantly extend the survival of DMG PDX models compared to all other regimens; a survival benefit amplified when combined with the anti-glycemic therapy metformin. Phosphoproteomic profiling identified increased Protein kinase C (PKC) signaling following paxalisib treatment. The combination of paxalisib and enzastaurin (PKC inhibitor) synergistically extended the survival of PDX models. Our optimized dosing regimen increased the preclinical benefits of paxalisib, with the combination of paxalisib with metformin, or paxalisib with enzastaurin, heralding rationally designed combination strategies for the treatment of DMG
2024-02-20 | PXD036114 | Pride
Project description:The blood-brain barier (BBB) function is impaired in several neurological diseases such as stroke. To better study the BBB dysfunction in stroke and to identify novel therapeutic targets, a detailed analysis of the neurovascular unit (NVU) cells that together regulate the BBB function is needed. To this end, we isolated the NVU cells EC, PC, AC, MG post stroke in mice using our newly developed SGD (Spitzer, Guérit, Devraj) method from the same starting material followed by RNA sequencing. Cells were isolated from both healthy appearing contralateral hemisphere and ipsilateral stroke hemisphere post tMCAO (1h occlusion, 23h repurfusion) using the SGD method. Each sample comprised 6 biological replicates with each replicate pooled from 3-4 male C57BL6 adult mouse brains either from contralateral or ipsilateral hemisphere post stroke. Only mice with neurological scores (mNSS) of atleast 8 were included for the NVU cell isolation. Our data showed regulation of several genes post stroke in each of the cell types analyzed with novel candidates that were co-regulated in the NVU cell types. As the blood-brain barrier (BBB) is co-regulated by several NVU cell types, we propose targeting the candidates co-regulated in multiple NVU cell-ytpes for novel and effective therapeutic options in stroke.
2022-07-20 | GSE163752 | GEO
Project description:The blood-brain barrier (BBB) is a multicellular neurovascular unit (NVU) that allows the selective passage of necessary molecules into the central nervous system (CNS), while limiting the entry of neurotoxins and most drugs. A crosstalk with pericytes and neural cells mediates the acquisition of specialized properties, such as the formation of tight junctions (TJs), in brain microvascular endothelial cells (BMECs). TJs limit the paracellular passage of solutes, thereby regulating CNS homeostasis. However, the mechanisms by which NVU cells communicate to mediate TJ formation remains a mystery. Retinoic acid (RA), a key signaling molecule during vertebrate embryonic development, is commonly used to enhance functional barrier properties in in vitro BBB models. However, its physiological relevance and affected pathways are not fully understood.
2022-08-01 | GSE202485 | GEO
Project description:Background: Pediatric high-grade gliomas (pHGGs), including diffuse midline gliomas (DMGs), are aggressive pediatric tumors with one of the poorest prognoses. Delta-24-RGD and ONC201 have shown promising efficacy as single agents for these tumors. However, the combination of both agents has not been evaluated. Methods: The production of functional viruses was assessed by immunoblotting and replication assays. The antitumor effect was evaluated in a panel of human and murine pHGG and DMG cell lines. RNAseq, the seahorse stress test, mitochondrial DNA content, and γH2A.X immunofluorescence were used to perform mechanistic studies. Mouse models of both diseases were used to assess the efficacy of the combination in vivo. The tumor immune microenvironment was evaluated using flow cytometry, RNAseq and multiplexed immunofluorescence staining. Results: The Delta-24-RGD/ONC201 combination did not affect the virus replication capability in human pHGG and DMG models in vitro. Cytotoxicity analysis showed that the combination treatment was either synergistic or additive. Mechanistically, the combination treatment increased nuclear DNA damage and maintained the metabolic perturbation and mitochondrial damage caused by each agent alone. Delta-24-RGD/ONC201 cotreatment extended the overall survival of mice implanted with human and murine pHGG and DMG cells, independent of H3 mutation status and location. Finally, combination treatment in murine DMG models revealed a reshaping of the tumor microenvironment to a proinflammatory phenotype. Conclusions: The Delta-24-RGD/ONC201 combination improved the efficacy compared to each agent alone in in vitro and in vivo models by potentiating nuclear DNA damage and in turn improving the antitumor (immune) response to each agent alone.
2024-05-09 | GSE255971 | GEO
Project description:Background: Pediatric high-grade gliomas (pHGGs), including diffuse midline gliomas (DMGs) are aggressive pediatric tumors harboring one of the poorest prognoses. Previous preclinical and clinical studies have demonstrated that oncolytic adenovirus Delta-24-RGD and the imipridone ONC201 are two promising therapies for these type of tumors as single agents. However, the combination of both agents has not been previously evaluated. Methods: Potential negative effects of ONC201 on the production of functional viruses were assessed by immunoblotting and replication assays. Antitumor effect was evaluated in a panel of human and murine pHGG and DMG cell lines. RNAseq, mTORC1 pathway analysis, Seahorse Stress Test, mitochondrial DNA content, and pH2A.X immunofluorescence were used to perform mechanistical studies. Models of both diseases were used to assess the efficacy of the combination in vivo. Tumor immune microenvironment was evaluated using flow cytometry. Results: ONC201 cotreatment with Delta-24-RGD did not affect the virus replication capability in human and murine pHGG and DMG models in vitro. Cytotoxicity analysis showed that cotreatment was either synergistic or additive. Mechanistically, combination treatment produces an increase of nuclear DNA damage and maintains the metabolic perturbation and mitochondrial damage caused by each agent alone. Delta-24-RGD/ONC201 cotreatment extends the overall survival of mice implanted with human and murine pHGG and DMG cells, independently of H3 mutational status. Finally, combination treatment in murine DMG models revealed a proinflammatory phenotype reshaping of the tumor microenvironment. Conclusions: Delta-24-RGD/ONC201 combination improves the efficacy of each agent alone in vitro and in vivo models, maintaining transcriptional and phenotypical changes, producing exacerbated nuclear DNA damage, and leading to an augmented antitumor immune response.
2024-05-09 | GSE243223 | GEO
Project description:Diffuse midline glioma (DMG) is a uniformly fatal pediatric, adolescent, and young adult cancer diagnosed in the midline structures of the brain. PI3K/Akt signaling is an overarching contributor to the poor outcomes of DMG patients due to their dependance on insulin and recurring mutations and amplifications in PI3K/Akt genes. Paxalisib (GDC-0084) is a potent PI3K/Akt inhibitor developed to penetrate the brain’s protective blood-brain barrier (BBB). We performed paxalisib regimen optimization by assessment of blood glucose levels, analysis in vivo pharmacokinetics/pharmacodynamics properties, and employed DMG patient derived xenograft (PDX) mouse models to determine preclinical efficacy. To identify novel combination strategies, we conducted high-resolution quantitative phosphoproteomics of DMG cells treated with paxalisib. Elevated blood glucose levels promoting hyperglycemia was seen in mice using paxalisib 10 mg/kg/day (~mouse equivalent human maximum tolerated dose- NCT03696355). Whereas 5 mg/kg/day, or 5mg/kg/b.i.d. (twice daily) non-significantly increased blood glucose levels compared to controls. Pharmacokinetic analysis of mouse tissues showed 5 mg/kg/b.i.d. increased paxalisib acumination in the brainstem, suppressing PI3K/Akt signaling to significantly extend the survival of DMG PDX models compared to all other regimens; a survival benefit amplified when combined with the anti-glycemic therapy metformin. Phosphoproteomic profiling identified increased Protein kinase C (PKC) signaling following paxalisib treatment. The combination of paxalisib and enzastaurin (PKC inhibitor) synergistically extended the survival of PDX models. Our optimized dosing regimen increased the preclinical benefits of paxalisib, with the combination of paxalisib with metformin, or paxalisib with enzastaurin, heralding rationally designed combination strategies for the treatment of DMG.
2024-02-20 | GSE246057 | GEO
Project description:Diffuse midline glioma (DMG) is a uniformly fatal pediatric, adolescent, and young adult cancer diagnosed in the midline structures of the brain. PI3K/Akt signaling is an overarching contributor to the poor outcomes of DMG patients due to their dependance on insulin and recurring mutations and amplifications in PI3K/Akt genes. Paxalisib (GDC-0084) is a potent PI3K/Akt inhibitor developed to penetrate the brain’s protective blood-brain barrier (BBB). We performed paxalisib regimen optimization by assessment of blood glucose levels, analysis in vivo pharmacokinetics/pharmacodynamics properties, and employed DMG patient derived xenograft (PDX) mouse models to determine preclinical efficacy. To identify novel combination strategies, we conducted high-resolution quantitative phosphoproteomics of DMG cells treated with paxalisib. Elevated blood glucose levels promoting hyperglycemia was seen in mice using paxalisib 10 mg/kg/day (~mouse equivalent human maximum tolerated dose- NCT03696355). Whereas 5 mg/kg/day, or 5mg/kg/b.i.d. (twice daily) non-significantly increased blood glucose levels compared to controls. Pharmacokinetic analysis of mouse tissues showed 5 mg/kg/b.i.d. increased paxalisib acumination in the brainstem, suppressing PI3K/Akt signaling to significantly extend the survival of DMG PDX models compared to all other regimens; a survival benefit amplified when combined with the anti-glycemic therapy metformin. Phosphoproteomic profiling identified increased Protein kinase C (PKC) signaling following paxalisib treatment. The combination of paxalisib and enzastaurin (PKC inhibitor) synergistically extended the survival of PDX models. Our optimized dosing regimen increased the preclinical benefits of paxalisib, with the combination of paxalisib with metformin, or paxalisib with enzastaurin, heralding rationally designed combination strategies for the treatment of DMG.
2024-02-20 | GSE211565 | GEO
Project description:Diffuse midline glioma (DMG) is a type of lethal brain tumor that develops mainly in children. The majority of DMG harbor the K27M mutation in histone H3. Oligodendrocyte progenitor cells (OPCs) in the brainstem are candidate cells-of-origin for DMG, yet there is no genetically engineered mouse model of DMG initiated in OPCs. Here, we used the RCAS/Tv-a avian retroviral system to generate DMG in Olig2-expressing progenitors and Nestin-expressing progenitors in the neonatal mouse brainstem. PDGF-A or PDGF-B overexpression, along with p53 deletion, resulted in gliomas in both models. Exogenous overexpression of H3.3K27M had a significant effect on tumor latency and tumor cell proliferation when compared with H3.3WT in Nestin+ cells but not in Olig2+ cells. Further, the fraction of H3.3K27M-positive cells was significantly lower in DMGs initiated in Olig2+ cells relative to Nestin+ cells, both in PDGF-A and PDGF-B-driven models, suggesting that the requirement for H3.3K27M is increased when tumorigenesis is initiated in Nestin+ cells. Therefore, we need to find how the tumorigenic effects of H3.3K27M are more oncogenic in Nestin+ cells than Olig2+ cells.
2021-10-05 | GSE184934 | GEO
Project description:The brain and spinal cord are endowed with particular vascular systems, known as the blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB) respectively, which maintain homeostasis between nervous parenchyma and peripheral circulation. Despite these common features, the BSCB presents structural and functional differences resulting in distinct vulnerability to pathological insults when compared to the BBB. Although, the heterogeneity of endothelial cell types underlies their remarkable ability to sub-specialize and provide specific requirements for a given vascular bed, very little is known concerning intrinsic differences between microvascular endothelial cells (MECs) derived from brain (BMECs) and spinal cord (SCMECs), including their response to inflammation. We used Agilent Whole Rattus Genome Microarray 4X44K to compare rat BMECs and SCMECs in both basal and inflammatory conditions; TNF-α-induced, TWEAK-induced and LPS-induced gene expression after 6 hr, 12 hr, 24 hr and 48 hr incubation.
2016-06-20 | E-MTAB-4696 | biostudies-arrayexpress