Project description:This study explores the circuit integration of human glioblastoma organoids (GBOs) in vivo in the adult mouse brain. We performed single cell RNA sequencing (scRNA-seq) to understand the cell state diversity of malignant tumor cells in GBOs at baseline and after stimulation by 1 mM acetylcholine (ACh) for 1 hour. Sliced neocortical organoids (SNOs) were also sequenced to study gene expression properties of neural stem cells (NSCs).
Project description:This study explores the circuit integration of human glioblastoma organoids (GBOs) in vivo in the adult mouse brain. Here, we performed RNA sequencing analysis of GBOs at baseline conditions and various treatment timepoints of 1 mM acetylcholine (ACh).
Project description:Neuronal activity-driven mechanisms impact glioblastoma cell proliferation and invasion (1–7), and glioblastoma remodels neuronal circuits (8,9). Distinct intratumoral regions maintain functional connectivity via a subpopulation of malignant cells that mediate tumor-intrinsic neuronal connectivity and synaptogenesis through their transcriptional programs (8). However, the effects of tumor-intrinsic neuronal activity on other cells, such as immune cells, remain unknown. Here we show that regions within glioblastomas displaying elevated connectivity are characterized by regional immunosuppression. This is accompanied by different cell compositions and inflammatory status of tumor-associated macrophages (TAMs) in the tumor microenvironment. In preclinical models, genetic knockout of Thrombospondin-1 (TSP1/Thbs1), a synaptogenic factor critical for glioma-induced neuronal circuit remodeling, in glioblastoma cells suppressed synaptogenesis and glutamatergic neuronal hyperexcitability. Moreover, this restored antigen-presentation and pro-inflammatory responses, promoted the infiltration of pro-inflammatory TAMs and CD8+ T-cells, and mitigated the immunosuppressive effect of TAMs on T-cell proliferation. Furthermore, pharmacological inhibition of glutamatergic excitatory neuronal signaling redirected TAMs toward a less immunosuppressive phenotype, resulting in prolonged mouse survival. Lastly, pharmacological inhibition of glutamatergic signaling showed potential to enhance the efficacy of immune cell-based therapy. Altogether, our results demonstrate previously unrecognized immunosuppression mechanisms resulting from glioma-neuronal circuit remodeling and suggest that targeting glioma-neuron-immune crosstalk could provide new avenues for immunotherapy.
Project description:Neuronal activity-driven mechanisms impact glioblastoma cell proliferation and invasion (1–7), and glioblastoma remodels neuronal circuits (8,9). Distinct intratumoral regions maintain functional connectivity via a subpopulation of malignant cells that mediate tumor-intrinsic neuronal connectivity and synaptogenesis through their transcriptional programs (8). However, the effects of tumor-intrinsic neuronal activity on other cells, such as immune cells, remain unknown. Here we show that regions within glioblastomas displaying elevated connectivity are characterized by regional immunosuppression. This is accompanied by different cell compositions and inflammatory status of tumor-associated macrophages (TAMs) in the tumor microenvironment. In preclinical models, genetic knockout of Thrombospondin-1 (TSP1/Thbs1), a synaptogenic factor critical for glioma-induced neuronal circuit remodeling, in glioblastoma cells suppressed synaptogenesis and glutamatergic neuronal hyperexcitability. Moreover, this restored antigen-presentation and pro-inflammatory responses, promoted the infiltration of pro-inflammatory TAMs and CD8+ T-cells, and mitigated the immunosuppressive effect of TAMs on T-cell proliferation. Furthermore, pharmacological inhibition of glutamatergic excitatory neuronal signaling redirected TAMs toward a less immunosuppressive phenotype, resulting in prolonged mouse survival. Lastly, pharmacological inhibition of glutamatergic signaling showed potential to enhance the efficacy of immune cell-based therapy. Altogether, our results demonstrate previously unrecognized immunosuppression mechanisms resulting from glioma-neuronal circuit remodeling and suggest that targeting glioma-neuron-immune crosstalk could provide new avenues for immunotherapy.
Project description:Gene expression profiling of distinct members of a neuronal circuit has the potential to identify candidate molecules and mechanisms that underlie the formation, organization and function of the circuit. To this end, we report here the application of a novel method to characterize RNAs from small numbers of specific Drosophila brain neurons, which belong to the circadian circuit. We identified three different sets of mRNAs enriched in different subclasses of clock neurons: one is enriched in all clock neurons, a second is enriched in PDF-positive clock neurons and a third is enriched in PDF-negative clock neurons. Moreover, we characterized 2 novel genes, Fer2 and dnocturnin, one from each subgroup, which highlight subgroup-specific features and play important roles in circadian rhythms. The methodology is a powerful tool not only to dissect the cellular and molecular basis of circadian rhythms but also to molecularly characterize other Drosophila neuronal circuits. Experiment Overall Design: Circadican related neuronal celltypes (Tim, Pdf) or general neurons (Elav) were labeled by GFP or YFP using specific Gal4 drivers. Expression of those celltypes were profiled after manual sorting of those GFP or YFP positive cells. 3 biological replicates were collected (except adult small pdf cells).
Project description:Gene expression profiling of distinct members of a neuronal circuit has the potential to identify candidate molecules and mechanisms that underlie the formation, organization and function of the circuit. To this end, we report here the application of a novel method to characterize RNAs from small numbers of specific Drosophila brain neurons, which belong to the circadian circuit. We identified three different sets of mRNAs enriched in different subclasses of clock neurons: one is enriched in all clock neurons, a second is enriched in PDF-positive clock neurons and a third is enriched in PDF-negative clock neurons. Moreover, we characterized 2 novel genes, Fer2 and dnocturnin, one from each subgroup, which highlight subgroup-specific features and play important roles in circadian rhythms. The methodology is a powerful tool not only to dissect the cellular and molecular basis of circadian rhythms but also to molecularly characterize other Drosophila neuronal circuits.
Project description:We have developed a nonheuristic genome topography scan (GTS) algorithm to characterize the patterns of genomic alterations in human glioblastoma (GBM), identifying frequent p18INK4C and p16INK4A codeletion. Functional reconstitution of p18INK4C in GBM cells null for both p16INK4A and p18INK4C resulted in impaired cell-cycle progression and tumorigenic potential. Conversely, RNAi-mediated depletion of p18INK4C in p16INK4A-deficient primary astrocytes or established GBM cells enhanced tumorigenicity in vitro and in vivo. Furthermore, acute suppression of p16INK4A in primary astrocytes induced a concomitant increase in p18INK4C. Together, these findings uncover a feedback regulatory circuit in the astrocytic lineage and demonstrate a bona fide tumor suppressor role for p18INK4C in human GBM wherein it functions cooperatively with other INK4 family members to constrain inappropriate proliferation. Keywords: SuperSeries DNA copy number and mRNA transcriptome of human glioblastoma tumors were profiled using Agilent and Affymetrix microarrays. This SuperSeries is composed of the following subset Series: GSE7602: Human GBM tumor vs Normal Human DNA GSE9171: Expression data from human GBM tumors and cell lines GSE9177: Human GBM tumor vs Normal Human DNA
Project description:Gut-brain connections monitor the intestinal tissue and its microbial and dietary content1, regulating both intestinal physiological functions such as nutrient absorption and motility2,3, and brain–wired feeding behaviour2. It is therefore plausible that circuits exist to detect gut microbes and relay this information to central nervous system (CNS) areas that, in turn, regulate gut physiology4. We characterized the influence of the microbiota on enteric–associated neurons (EAN) by combining gnotobiotic mouse models with transcriptomics, circuit–tracing methods, and functional manipulation. We found that the gut microbiome modulates gut–extrinsic sympathetic neurons; while microbiota depletion led to increased cFos expression, colonization of germ-free mice with short-chain fatty acid–producing bacteria suppressed cFos expression in the gut sympathetic ganglia. Chemogenetic manipulations, translational profiling, and anterograde tracing identified a subset of distal intestine-projecting vagal neurons positioned to play an afferent role in microbiota–mediated modulation of gut sympathetic neurons. Retrograde polysynaptic neuronal tracing from the intestinal wall identified brainstem sensory nuclei activated during microbial depletion, as well as efferent sympathetic premotor glutamatergic neurons that regulate gastrointestinal transit. These results reveal microbiota–dependent control of gut extrinsic sympathetic activation through a gut-brain circuit.