TY - JOUR
AB - The complexity of the microenvironment effects on cell response, show accumulating evidence that glioblastoma (GBM) migration and invasiveness are influenced by the mechanical rigidity of their surroundings. The epithelial–mesenchymal transition (EMT) is a well-recognized driving force of the invasive behavior of cancer. However, the primary mechanisms of EMT initiation and progression remain unclear. We have previously showed that certain substrate stiffness can selectively stimulate human GBM U251-MG and GL15 glioblastoma cell lines motility. The present study unifies several known EMT mediators to uncover the reason of the regulation and response to these stiffnesses. Our results revealed that changing the rigidity of the mechanical environment tuned the response of both cell lines through change in morphological features, epithelial-mesenchymal markers (E-, N-Cadherin), EGFR and ROS expressions in an interrelated manner. Specifically, a stiffer microenvironment induced a mesenchymal cell shape, a more fragmented morphology, higher intracellular cytosolic ROS expression and lower mitochondrial ROS. Finally, we observed that cells more motile showed a more depolarized mitochondrial membrane potential. Unravelling the process that regulates GBM cells’ infiltrative behavior could provide new opportunities for identification of new targets and less invasive approaches for treatment.
AU - Basilico, Bernadette
AU - Palamà, Ilaria Elena
AU - D’Amone, Stefania
AU - Lauro, Clotilde
AU - Rosito, Maria
AU - Grieco, Maddalena
AU - Ratano, Patrizia
AU - Cordella, Federica
AU - Sanchini, Caterina
AU - Di Angelantonio, Silvia
AU - Ragozzino, Davide
AU - Cascione, Mariafrancesca
AU - Gigli, Giuseppe
AU - Cortese, Barbara
ID - 12268
JF - Frontiers in Oncology
KW - Cancer Research
KW - Oncology
SN - 2234-943X
TI - Substrate stiffness effect on molecular crosstalk of epithelial-mesenchymal transition mediators of human glioblastoma cells
VL - 12
ER -
TY - JOUR
AB - Microglia cells are active players in regulating synaptic development and plasticity in the brain. However, how they influence the normal functioning of synapses is largely unknown. In this study, we characterized the effects of pharmacological microglia depletion, achieved by administration of PLX5622, on hippocampal CA3-CA1 synapses of adult wild type mice. Following microglial depletion, we observed a reduction of spontaneous and evoked glutamatergic activity associated with a decrease of dendritic spine density. We also observed the appearance of immature synaptic features and higher levels of plasticity. Microglia depleted mice showed a deficit in the acquisition of the Novel Object Recognition task. These events were accompanied by hippocampal astrogliosis, although in the absence ofneuroinflammatory condition. PLX-induced synaptic changes were absent in Cx3cr1−/− mice, highlighting the role of CX3CL1/CX3CR1 axis in microglia control of synaptic functioning. Remarkably, microglia repopulation after PLX5622 withdrawal was associated with the recovery of hippocampal synapses and learning functions. Altogether, these data demonstrate that microglia contribute to normal synaptic functioning in the adult brain and that their removal induces reversible changes in organization and activity of glutamatergic synapses.
AU - Basilico, Bernadette
AU - Ferrucci, Laura
AU - Ratano, Patrizia
AU - Golia, Maria T.
AU - Grimaldi, Alfonso
AU - Rosito, Maria
AU - Ferretti, Valentina
AU - Reverte, Ingrid
AU - Sanchini, Caterina
AU - Marrone, Maria C.
AU - Giubettini, Maria
AU - De Turris, Valeria
AU - Salerno, Debora
AU - Garofalo, Stefano
AU - St‐Pierre, Marie‐Kim
AU - Carrier, Micael
AU - Renzi, Massimiliano
AU - Pagani, Francesca
AU - Modi, Brijesh
AU - Raspa, Marcello
AU - Scavizzi, Ferdinando
AU - Gross, Cornelius T.
AU - Marinelli, Silvia
AU - Tremblay, Marie‐Ève
AU - Caprioli, Daniele
AU - Maggi, Laura
AU - Limatola, Cristina
AU - Di Angelantonio, Silvia
AU - Ragozzino, Davide
ID - 10818
IS - 1
JF - Glia
KW - Cellular and Molecular Neuroscience
KW - Neurology
SN - 0894-1491
TI - Microglia control glutamatergic synapses in the adult mouse hippocampus
VL - 70
ER -
TY - GEN
AB - Complex wiring between neurons underlies the information-processing network enabling all brain functions, including cognition and memory. For understanding how the network is structured, processes information, and changes over time, comprehensive visualization of the architecture of living brain tissue with its cellular and molecular components would open up major opportunities. However, electron microscopy (EM) provides nanometre-scale resolution required for full in-silico reconstruction1–5, yet is limited to fixed specimens and static representations. Light microscopy allows live observation, with super-resolution approaches6–12 facilitating nanoscale visualization, but comprehensive 3D-reconstruction of living brain tissue has been hindered by tissue photo-burden, photobleaching, insufficient 3D-resolution, and inadequate signal-to-noise ratio (SNR). Here we demonstrate saturated reconstruction of living brain tissue. We developed an integrated imaging and analysis technology, adapting stimulated emission depletion (STED) microscopy6,13 in extracellularly labelled tissue14 for high SNR and near-isotropic resolution. Centrally, a two-stage deep-learning approach leveraged previously obtained information on sample structure to drastically reduce photo-burden and enable automated volumetric reconstruction down to single synapse level. Live reconstruction provides unbiased analysis of tissue architecture across time in relation to functional activity and targeted activation, and contextual understanding of molecular labelling. This adoptable technology will facilitate novel insights into the dynamic functional architecture of living brain tissue.
AU - Velicky, Philipp
AU - Miguel Villalba, Eder
AU - Michalska, Julia M
AU - Wei, Donglai
AU - Lin, Zudi
AU - Watson, Jake
AU - Troidl, Jakob
AU - Beyer, Johanna
AU - Ben Simon, Yoav
AU - Sommer, Christoph M
AU - Jahr, Wiebke
AU - Cenameri, Alban
AU - Broichhagen, Johannes
AU - Grant, Seth G. N.
AU - Jonas, Peter M
AU - Novarino, Gaia
AU - Pfister, Hanspeter
AU - Bickel, Bernd
AU - Danzl, Johann G
ID - 11943
T2 - bioRxiv
TI - Saturated reconstruction of living brain tissue
ER -
TY - GEN
AB - Mapping the complex and dense arrangement of cells and their connectivity in brain tissue demands nanoscale spatial resolution imaging. Super-resolution optical microscopy excels at visualizing specific molecules and individual cells but fails to provide tissue context. Here we developed Comprehensive Analysis of Tissues across Scales (CATS), a technology to densely map brain tissue architecture from millimeter regional to nanoscopic synaptic scales in diverse chemically fixed brain preparations, including rodent and human. CATS leverages fixation-compatible extracellular labeling and advanced optical readout, in particular stimulated-emission depletion and expansion microscopy, to comprehensively delineate cellular structures. It enables 3D-reconstructing single synapses and mapping synaptic connectivity by identification and tailored analysis of putative synaptic cleft regions. Applying CATS to the hippocampal mossy fiber circuitry, we demonstrate its power to reveal the system’s molecularly informed ultrastructure across spatial scales and assess local connectivity by reconstructing and quantifying the synaptic input and output structure of identified neurons.
AU - Michalska, Julia M
AU - Lyudchik, Julia
AU - Velicky, Philipp
AU - Korinkova, Hana
AU - Watson, Jake
AU - Cenameri, Alban
AU - Sommer, Christoph M
AU - Venturino, Alessandro
AU - Roessler, Karl
AU - Czech, Thomas
AU - Siegert, Sandra
AU - Novarino, Gaia
AU - Jonas, Peter M
AU - Danzl, Johann G
ID - 11950
T2 - bioRxiv
TI - Uncovering brain tissue architecture across scales with super-resolution light microscopy
ER -
TY - JOUR
AB - Mutations in the chromodomain helicase DNA-binding 8 (CHD8) gene are a frequent cause of autism spectrum disorder (ASD). While its phenotypic spectrum often encompasses macrocephaly, implicating cortical abnormalities, how CHD8 haploinsufficiency affects neurodevelopmental is unclear. Here, employing human cerebral organoids, we find that CHD8 haploinsufficiency disrupted neurodevelopmental trajectories with an accelerated and delayed generation of, respectively, inhibitory and excitatory neurons that yields, at days 60 and 120, symmetrically opposite expansions in their proportions. This imbalance is consistent with an enlargement of cerebral organoids as an in vitro correlate of patients’ macrocephaly. Through an isogenic design of patient-specific mutations and mosaic organoids, we define genotype-phenotype relationships and uncover their cell-autonomous nature. Our results define cell-type-specific CHD8-dependent molecular defects related to an abnormal program of proliferation and alternative splicing. By identifying cell-type-specific effects of CHD8 mutations, our study uncovers reproducible developmental alterations that may be employed for neurodevelopmental disease modeling.
AU - Villa, Carlo Emanuele
AU - Cheroni, Cristina
AU - Dotter, Christoph
AU - López-Tóbon, Alejandro
AU - Oliveira, Bárbara
AU - Sacco, Roberto
AU - Yahya, Aysan Çerağ
AU - Morandell, Jasmin
AU - Gabriele, Michele
AU - Tavakoli, Mojtaba
AU - Lyudchik, Julia
AU - Sommer, Christoph M
AU - Gabitto, Mariano
AU - Danzl, Johann G
AU - Testa, Giuseppe
AU - Novarino, Gaia
ID - 11160
IS - 1
JF - Cell Reports
KW - General Biochemistry
KW - Genetics and Molecular Biology
SN - 2211-1247
TI - CHD8 haploinsufficiency links autism to transient alterations in excitatory and inhibitory trajectories
VL - 39
ER -
TY - THES
AB - Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by behavioral symptoms such as problems in social communication and interaction, as
well as repetitive, restricted behaviors and interests. These disorders show a high degree
of heritability and hundreds of risk genes have been identifed using high throughput
sequencing technologies. This genetic heterogeneity has hampered eforts in understanding
the pathogenesis of ASD but at the same time given rise to the concept of convergent
mechanisms. Previous studies have identifed that risk genes for ASD broadly converge
onto specifc functional categories with transcriptional regulation being one of the biggest
groups. In this thesis, I focus on this subgroup of genes and investigate the gene regulatory
consequences of some of them in the context of neurodevelopment.
First, we showed that mutations in the ASD and intellectual disability risk gene Setd5 lead
to perturbations of gene regulatory programs in early cell fate specifcation. In addition,
adult animals display abnormal learning behavior which is mirrored at the transcriptional
level by altered activity dependent regulation of postsynaptic gene expression. Lastly,
we link the regulatory function of Setd5 to its interaction with the Paf1 and the NCoR
complex.
Second, by modeling the heterozygous loss of the top ASD gene CHD8 in human cerebral
organoids we demonstrate profound changes in the developmental trajectories of both
inhibitory and excitatory neurons using single cell RNA-sequencing. While the former
were generated earlier in CHD8+/- organoids, the generation of the latter was shifted to
later times in favor of a prolonged progenitor expansion phase and ultimately increased
organoid size.
Finally, by modeling heterozygous mutations for four ASD associated chromatin modifers,
ASH1L, KDM6B, KMT5B, and SETD5 in human cortical spheroids we show evidence of
regulatory convergence across three of those genes. We observe a shift from dorsal cortical
excitatory neuron fates towards partially ventralized cell types resembling cells from the
lateral ganglionic eminence. As this project is still ongoing at the time of writing, future
experiments will aim at elucidating the regulatory mechanisms underlying this shift with
the aim of linking these three ASD risk genes through biological convergence.
AU - Dotter, Christoph
ID - 12364
SN - 2663-337X
TI - Transcriptional consequences of mutations in genes associated with Autism Spectrum Disorder
ER -
TY - JOUR
AB - Mutations affecting mTOR or RAS signaling underlie defined syndromes (the so-called mTORopathies and RASopathies) with high risk for Autism Spectrum Disorder (ASD). These syndromes show a broad variety of somatic phenotypes including cancers, skin abnormalities, heart disease and facial dysmorphisms. Less well studied are the neuropsychiatric symptoms such as ASD. Here, we assess the relevance of these signalopathies in ASD reviewing genetic, human cell model, rodent studies and clinical trials. We conclude that signalopathies have an increased liability for ASD and that, in particular, ASD individuals with dysmorphic features and intellectual disability (ID) have a higher chance for disruptive mutations in RAS- and mTOR-related genes. Studies on rodent and human cell models confirm aberrant neuronal development as the underlying pathology. Human studies further suggest that multiple hits are necessary to induce the respective phenotypes. Recent clinical trials do only report improvements for comorbid conditions such as epilepsy or cancer but not for behavioral aspects. Animal models show that treatment during early development can rescue behavioral phenotypes. Taken together, we suggest investigating the differential roles of mTOR and RAS signaling in both human and rodent models, and to test drug treatment both during and after neuronal development in the available model systems
AU - Vasic, Verica
AU - Jones, Mattson S.O.
AU - Haslinger, Denise
AU - Knaus, Lisa
AU - Schmeisser, Michael J.
AU - Novarino, Gaia
AU - Chiocchetti, Andreas G.
ID - 10281
IS - 11
JF - Genes
TI - Translating the role of mtor-and ras-associated signalopathies in autism spectrum disorder: Models, mechanisms and treatment
VL - 12
ER -
TY - JOUR
AB - De novo protein synthesis is required for synapse modifications underlying stable memory encoding. Yet neurons are highly compartmentalized cells and how protein synthesis can be regulated at the synapse level is unknown. Here, we characterize neuronal signaling complexes formed by the postsynaptic scaffold GIT1, the mechanistic target of rapamycin (mTOR) kinase, and Raptor that couple synaptic stimuli to mTOR-dependent protein synthesis; and identify NMDA receptors containing GluN3A subunits as key negative regulators of GIT1 binding to mTOR. Disruption of GIT1/mTOR complexes by enhancing GluN3A expression or silencing GIT1 inhibits synaptic mTOR activation and restricts the mTOR-dependent translation of specific activity-regulated mRNAs. Conversely, GluN3A removal enables complex formation, potentiates mTOR-dependent protein synthesis, and facilitates the consolidation of associative and spatial memories in mice. The memory enhancement becomes evident with light or spaced training, can be achieved by selectively deleting GluN3A from excitatory neurons during adulthood, and does not compromise other aspects of cognition such as memory flexibility or extinction. Our findings provide mechanistic insight into synaptic translational control and reveal a potentially selective target for cognitive enhancement.
AU - Conde-Dusman, María J
AU - Dey, Partha N
AU - Elía-Zudaire, Óscar
AU - Garcia Rabaneda, Luis E
AU - García-Lira, Carmen
AU - Grand, Teddy
AU - Briz, Victor
AU - Velasco, Eric R
AU - Andero Galí, Raül
AU - Niñerola, Sergio
AU - Barco, Angel
AU - Paoletti, Pierre
AU - Wesseling, John F
AU - Gardoni, Fabrizio
AU - Tavalin, Steven J
AU - Perez-Otaño, Isabel
ID - 10301
JF - eLife
KW - general immunology and microbiology
KW - general biochemistry
KW - genetics and molecular biology
KW - general medicine
KW - general neuroscience
SN - 2050-084X
TI - Control of protein synthesis and memory by GluN3A-NMDA receptors through inhibition of GIT1/mTORC1 assembly
VL - 10
ER -
TY - JOUR
AB - Chronic psychological stress is one of the most important triggers and environmental risk factors for neuropsychiatric disorders. Chronic stress can influence all organs via the secretion of stress hormones, including glucocorticoids by the adrenal glands, which coordinate the stress response across the body. In the brain, glucocorticoid receptors (GR) are expressed by various cell types including microglia, which are its resident immune cells regulating stress-induced inflammatory processes. To study the roles of microglial GR under normal homeostatic conditions and following chronic stress, we generated a mouse model in which the GR gene is depleted in microglia specifically at adulthood to prevent developmental confounds. We first confirmed that microglia were depleted in GR in our model in males and females among the cingulate cortex and the hippocampus, both stress-sensitive brain regions. Then, cohorts of microglial-GR depleted and wild-type (WT) adult female mice were housed for 3 weeks in a standard or stressful condition, using a chronic unpredictable mild stress (CUMS) paradigm. CUMS induced stress-related behavior in both microglial-GR depleted and WT animals as demonstrated by a decrease of both saccharine preference and progressive ratio breakpoint. Nevertheless, the hippocampal microglial and neural mechanisms underlying the adaptation to stress occurred differently between the two genotypes. Upon CUMS exposure, microglial morphology was altered in the WT controls, without any apparent effect in microglial-GR depleted mice. Furthermore, in the standard environment condition, GR depleted-microglia showed increased expression of pro-inflammatory genes, and genes involved in microglial homeostatic functions (such as Trem2, Cx3cr1 and Mertk). On the contrary, in CUMS condition, GR depleted-microglia showed reduced expression levels of pro-inflammatory genes and increased neuroprotective as well as anti-inflammatory genes compared to WT-microglia. Moreover, in microglial-GR depleted mice, but not in WT mice, CUMS led to a significant reduction of CA1 long-term potentiation and paired-pulse ratio. Lastly, differences in adult hippocampal neurogenesis were observed between the genotypes during normal homeostatic conditions, with microglial-GR deficiency increasing the formation of newborn neurons in the dentate gyrus subgranular zone independently from stress exposure. Together, these findings indicate that, although the deletion of microglial GR did not prevent the animal’s ability to respond to stress, it contributed to modulating hippocampal functions in both standard and stressful conditions, notably by shaping the microglial response to chronic stress.
AU - Picard, Katherine
AU - Bisht, Kanchan
AU - Poggini, Silvia
AU - Garofalo, Stefano
AU - Golia, Maria Teresa
AU - Basilico, Bernadette
AU - Abdallah, Fatima
AU - Ciano Albanese, Naomi
AU - Amrein, Irmgard
AU - Vernoux, Nathalie
AU - Sharma, Kaushik
AU - Hui, Chin Wai
AU - C. Savage, Julie
AU - Limatola, Cristina
AU - Ragozzino, Davide
AU - Maggi, Laura
AU - Branchi, Igor
AU - Tremblay, Marie Ève
ID - 9953
JF - Brain, Behavior, and Immunity
SN - 0889-1591
TI - Microglial-glucocorticoid receptor depletion alters the response of hippocampal microglia and neurons in a chronic unpredictable mild stress paradigm in female mice
VL - 97
ER -
TY - JOUR
AB - P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2) restrict at the blood–brain barrier (BBB) the brain distribution of the majority of currently known molecularly targeted anticancer drugs. To improve brain delivery of dual ABCB1/ABCG2 substrates, both ABCB1 and ABCG2 need to be inhibited simultaneously at the BBB. We examined the feasibility of simultaneous ABCB1/ABCG2 inhibition with i.v. co-infusion of erlotinib and tariquidar by studying brain distribution of the model ABCB1/ABCG2 substrate [11C]erlotinib in mice and rhesus macaques with PET. Tolerability of the erlotinib/tariquidar combination was assessed in human embryonic stem cell-derived cerebral organoids. In mice and macaques, baseline brain distribution of [11C]erlotinib was low (brain distribution volume, VT,brain < 0.3 mL/cm3). Co-infusion of erlotinib and tariquidar increased VT,brain in mice by 3.0-fold and in macaques by 3.4- to 5.0-fold, while infusion of erlotinib alone or tariquidar alone led to less pronounced VT,brain increases in both species. Treatment of cerebral organoids with erlotinib/tariquidar led to an induction of Caspase-3-dependent apoptosis. Co-infusion of erlotinib/tariquidar may potentially allow for complete ABCB1/ABCG2 inhibition at the BBB, while simultaneously achieving brain-targeted EGFR inhibition. Our protocol may be applicable to enhance brain delivery of molecularly targeted anticancer drugs for a more effective treatment of brain tumors.
AU - Tournier, N
AU - Goutal, S
AU - Mairinger, S
AU - Lozano, IH
AU - Filip, T
AU - Sauberer, M
AU - Caillé, F
AU - Breuil, L
AU - Stanek, J
AU - Freeman, AF
AU - Novarino, Gaia
AU - Truillet, C
AU - Wanek, T
AU - Langer, O
ID - 8730
IS - 7
JF - Journal of Cerebral Blood Flow and Metabolism
SN - 0271-678x
TI - Complete inhibition of ABCB1 and ABCG2 at the blood-brain barrier by co-infusion of erlotinib and tariquidar to improve brain delivery of the model ABCB1/ABCG2 substrate [11C]erlotinib
VL - 41
ER -