TY - GEN AB - Human brain organoids represent a powerful tool for the study of human neurological diseases particularly those that impact brain growth and structure. However, many neurological diseases lack obvious anatomical abnormalities, yet significantly impact neural network functions, raising the question of whether organoids possess sufficient neural network architecture and complexity to model these conditions. Here, we explore the network level functions of brain organoids using calcium sensor imaging and extracellular recording approaches that together reveal the existence of complex oscillatory network behaviors reminiscent of intact brain preparations. We further demonstrate strikingly abnormal epileptiform network activity in organoids derived from a Rett Syndrome patient despite only modest anatomical differences from isogenically matched controls, and rescue with an unconventional neuromodulatory drug Pifithrin-α. Together, these findings provide an essential foundation for the utilization of human brain organoids to study intact and disordered human brain network formation and illustrate their utility in therapeutic discovery. AU - Samarasinghe, Ranmal A. AU - Miranda, Osvaldo AU - Buth, Jessie E. AU - Mitchell, Simon AU - Ferando, Isabella AU - Watanabe, Momoko AU - Kurdian, Arinnae AU - Golshani, Peyman AU - Plath, Kathrin AU - Lowry, William E. AU - Parent, Jack M. AU - Mody, Istvan AU - Novitch, Bennett G. ID - 6995 SN - 1097-6256 TI - Identification of neural oscillations and epileptiform changes in human brain organoids VL - 24 ER - TY - JOUR AB - Brain neurons arise from relatively few progenitors generating an enormous diversity of neuronal types. Nonetheless, a cardinal feature of mammalian brain neurogenesis is thought to be that excitatory and inhibitory neurons derive from separate, spatially segregated progenitors. Whether bi-potential progenitors with an intrinsic capacity to generate both lineages exist and how such a fate decision may be regulated are unknown. Using cerebellar development as a model, we discover that individual progenitors can give rise to both inhibitory and excitatory lineages. Gradations of Notch activity determine the fates of the progenitors and their daughters. Daughters with the highest levels of Notch activity retain the progenitor fate, while intermediate levels of Notch activity generate inhibitory neurons, and daughters with very low levels of Notch signaling adopt the excitatory fate. Therefore, Notch-mediated binary cell fate choice is a mechanism for regulating the ratio of excitatory to inhibitory neurons from common progenitors. AU - Zhang, Tingting AU - Liu, Tengyuan AU - Mora, Natalia AU - Guegan, Justine AU - Bertrand, Mathilde AU - Contreras, Ximena AU - Hansen, Andi H AU - Streicher, Carmen AU - Anderle, Marica AU - Danda, Natasha AU - Tiberi, Luca AU - Hippenmeyer, Simon AU - Hassan, Bassem A. ID - 8546 IS - 10 JF - Cell Reports TI - Generation of excitatory and inhibitory neurons from common progenitors via Notch signaling in the cerebellum VL - 35 ER - TY - JOUR AB - Genomic imprinting is an epigenetic mechanism that results in parental allele-specific expression of ~1% of all genes in mouse and human. Imprinted genes are key developmental regulators and play pivotal roles in many biological processes such as nutrient transfer from the mother to offspring and neuronal development. Imprinted genes are also involved in human disease, including neurodevelopmental disorders, and often occur in clusters that are regulated by a common imprint control region (ICR). In extra-embryonic tissues ICRs can act over large distances, with the largest surrounding Igf2r spanning over 10 million base-pairs. Besides classical imprinted expression that shows near exclusive maternal or paternal expression, widespread biased imprinted expression has been identified mainly in brain. In this review we discuss recent developments mapping cell type specific imprinted expression in extra-embryonic tissues and neocortex in the mouse. We highlight the advantages of using an inducible uniparental chromosome disomy (UPD) system to generate cells carrying either two maternal or two paternal copies of a specific chromosome to analyze the functional consequences of genomic imprinting. Mosaic Analysis with Double Markers (MADM) allows fluorescent labeling and concomitant induction of UPD sparsely in specific cell types, and thus to over-express or suppress all imprinted genes on that chromosome. To illustrate the utility of this technique, we explain how MADM-induced UPD revealed new insights about the function of the well-studied Cdkn1c imprinted gene, and how MADM-induced UPDs led to identification of highly cell type specific phenotypes related to perturbed imprinted expression in the mouse neocortex. Finally, we give an outlook on how MADM could be used to probe cell type specific imprinted expression in other tissues in mouse, particularly in extra-embryonic tissues. AU - Pauler, Florian AU - Hudson, Quanah AU - Laukoter, Susanne AU - Hippenmeyer, Simon ID - 9188 IS - 5 JF - Neurochemistry International KW - Cell Biology KW - Cellular and Molecular Neuroscience SN - 0197-0186 TI - Inducible uniparental chromosome disomy to probe genomic imprinting at single-cell level in brain and beyond VL - 145 ER - TY - JOUR AB - In mammalian genomes, differentially methylated regions (DMRs) and histone marks including trimethylation of histone 3 lysine 27 (H3K27me3) at imprinted genes are asymmetrically inherited to control parentally-biased gene expression. However, neither parent-of-origin-specific transcription nor imprints have been comprehensively mapped at the blastocyst stage of preimplantation development. Here, we address this by integrating transcriptomic and epigenomic approaches in mouse preimplantation embryos. We find that seventy-one genes exhibit previously unreported parent-of-origin-specific expression in blastocysts (nBiX: novel blastocyst-imprinted expressed). Uniparental expression of nBiX genes disappears soon after implantation. Micro-whole-genome bisulfite sequencing (µWGBS) of individual uniparental blastocysts detects 859 DMRs. We further find that 16% of nBiX genes are associated with a DMR, whereas most are associated with parentally-biased H3K27me3, suggesting a role for Polycomb-mediated imprinting in blastocysts. nBiX genes are clustered: five clusters contained at least one published imprinted gene, and five clusters exclusively contained nBiX genes. These data suggest that early development undergoes a complex program of stage-specific imprinting involving different tiers of regulation. AU - Santini, Laura AU - Halbritter, Florian AU - Titz-Teixeira, Fabian AU - Suzuki, Toru AU - Asami, Maki AU - Ma, Xiaoyan AU - Ramesmayer, Julia AU - Lackner, Andreas AU - Warr, Nick AU - Pauler, Florian AU - Hippenmeyer, Simon AU - Laue, Ernest AU - Farlik, Matthias AU - Bock, Christoph AU - Beyer, Andreas AU - Perry, Anthony C.F. AU - Leeb, Martin ID - 9601 IS - 1 JF - Nature Communications TI - Genomic imprinting in mouse blastocysts is predominantly associated with H3K27me3 VL - 12 ER - TY - JOUR AB - Mosaic analysis with double markers (MADM) offers one approach to visualize and concomitantly manipulate genetically defined cells in mice with single-cell resolution. MADM applications include the analysis of lineage, single-cell morphology and physiology, genomic imprinting phenotypes, and dissection of cell-autonomous gene functions in vivo in health and disease. Yet, MADM can only be applied to <25% of all mouse genes on select chromosomes to date. To overcome this limitation, we generate transgenic mice with knocked-in MADM cassettes near the centromeres of all 19 autosomes and validate their use across organs. With this resource, >96% of the entire mouse genome can now be subjected to single-cell genetic mosaic analysis. Beyond a proof of principle, we apply our MADM library to systematically trace sister chromatid segregation in distinct mitotic cell lineages. We find striking chromosome-specific biases in segregation patterns, reflecting a putative mechanism for the asymmetric segregation of genetic determinants in somatic stem cell division. AU - Contreras, Ximena AU - Amberg, Nicole AU - Davaatseren, Amarbayasgalan AU - Hansen, Andi H AU - Sonntag, Johanna AU - Andersen, Lill AU - Bernthaler, Tina AU - Streicher, Carmen AU - Heger, Anna-Magdalena AU - Johnson, Randy L. AU - Schwarz, Lindsay A. AU - Luo, Liqun AU - Rülicke, Thomas AU - Hippenmeyer, Simon ID - 9603 IS - 12 JF - Cell Reports TI - A genome-wide library of MADM mice for single-cell genetic mosaic analysis VL - 35 ER - TY - JOUR AB - Endometriosis is a common gynecological disorder characterized by ectopic growth of endometrium outside the uterus and is associated with chronic pain and infertility. We investigated the role of the long intergenic noncoding RNA 01133 (LINC01133) in endometriosis, an lncRNA that has been implicated in several types of cancer. We found that LINC01133 is upregulated in ectopic endometriotic lesions. As expression appeared higher in the epithelial endometrial layer, we performed a siRNA knockdown of LINC01133 in an endometriosis epithelial cell line. Phenotypic assays indicated that LINC01133 may promote proliferation and suppress cellular migration, and affect the cytoskeleton and morphology of the cells. Gene ontology analysis of differentially expressed genes indicated that cell proliferation and migration pathways were affected in line with the observed phenotype. We validated upregulation of p21 and downregulation of Cyclin A at the protein level, which together with the quantification of the DNA content using fluorescence-activated cell sorting (FACS) analysis indicated that the observed effects on cellular proliferation may be due to changes in cell cycle. Further, we found testis-specific protein kinase 1 (TESK1) kinase upregulation corresponding with phosphorylation and inactivation of actin severing protein Cofilin, which could explain changes in the cytoskeleton and cellular migration. These results indicate that endometriosis is associated with LINC01133 upregulation, which may affect pathogenesis via the cellular proliferation and migration pathways. AU - Yotova, Iveta AU - Hudson, Quanah J. AU - Pauler, Florian AU - Proestling, Katharina AU - Haslinger, Isabella AU - Kuessel, Lorenz AU - Perricos, Alexandra AU - Husslein, Heinrich AU - Wenzl, René ID - 9906 IS - 16 JF - International Journal of Molecular Sciences SN - 16616596 TI - LINC01133 inhibits invasion and promotes proliferation in an endometriosis epithelial cell line VL - 22 ER - TY - JOUR AB - The sensory and cognitive abilities of the mammalian neocortex are underpinned by intricate columnar and laminar circuits formed from an array of diverse neuronal populations. One approach to determining how interactions between these circuit components give rise to complex behavior is to investigate the rules by which cortical circuits are formed and acquire functionality during development. This review summarizes recent research on the development of the neocortex, from genetic determination in neural stem cells through to the dynamic role that specific neuronal populations play in the earliest circuits of neocortex, and how they contribute to emergent function and cognition. While many of these endeavors take advantage of model systems, consideration will also be given to advances in our understanding of activity in nascent human circuits. Such cross-species perspective is imperative when investigating the mechanisms underlying the dysfunction of early neocortical circuits in neurodevelopmental disorders, so that one can identify targets amenable to therapeutic intervention. AU - Hanganu-Opatz, Ileana L. AU - Butt, Simon J. B. AU - Hippenmeyer, Simon AU - De Marco García, Natalia V. AU - Cardin, Jessica A. AU - Voytek, Bradley AU - Muotri, Alysson R. ID - 9073 IS - 5 JF - The Journal of Neuroscience KW - General Neuroscience SN - 0270-6474 TI - The logic of developing neocortical circuits in health and disease VL - 41 ER - TY - JOUR AB - Astrocytes extensively infiltrate the neuropil to regulate critical aspects of synaptic development and function. This process is regulated by transcellular interactions between astrocytes and neurons via cell adhesion molecules. How astrocytes coordinate developmental processes among one another to parse out the synaptic neuropil and form non-overlapping territories is unknown. Here we identify a molecular mechanism regulating astrocyte-astrocyte interactions during development to coordinate astrocyte morphogenesis and gap junction coupling. We show that hepaCAM, a disease-linked, astrocyte-enriched cell adhesion molecule, regulates astrocyte competition for territory and morphological complexity in the developing mouse cortex. Furthermore, conditional deletion of Hepacam from developing astrocytes significantly impairs gap junction coupling between astrocytes and disrupts the balance between synaptic excitation and inhibition. Mutations in HEPACAM cause megalencephalic leukoencephalopathy with subcortical cysts in humans. Therefore, our findings suggest that disruption of astrocyte self-organization mechanisms could be an underlying cause of neural pathology. AU - Baldwin, Katherine T. AU - Tan, Christabel X. AU - Strader, Samuel T. AU - Jiang, Changyu AU - Savage, Justin T. AU - Elorza-Vidal, Xabier AU - Contreras, Ximena AU - Rülicke, Thomas AU - Hippenmeyer, Simon AU - Estévez, Raúl AU - Ji, Ru-Rong AU - Eroglu, Cagla ID - 9793 IS - 15 JF - Neuron SN - 0896-6273 TI - HepaCAM controls astrocyte self-organization and coupling VL - 109 ER - TY - JOUR AB - Adeno-associated viruses (AAVs) are widely used to deliver genetic material in vivo to distinct cell types such as neurons or glial cells, allowing for targeted manipulation. Transduction of microglia is mostly excluded from this strategy, likely due to the cells’ heterogeneous state upon environmental changes, which makes AAV design challenging. Here, we established the retina as a model system for microglial AAV validation and optimization. First, we show that AAV2/6 transduced microglia in both synaptic layers, where layer preference corresponds to the intravitreal or subretinal delivery method. Surprisingly, we observed significantly enhanced microglial transduction during photoreceptor degeneration. Thus, we modified the AAV6 capsid to reduce heparin binding by introducing four point mutations (K531E, R576Q, K493S, and K459S), resulting in increased microglial transduction in the outer plexiform layer. Finally, to improve microglial-specific transduction, we validated a Cre-dependent transgene delivery cassette for use in combination with the Cx3cr1CreERT2 mouse line. Together, our results provide a foundation for future studies optimizing AAV-mediated microglia transduction and highlight that environmental conditions influence microglial transduction efficiency. AU - Maes, Margaret E AU - Wögenstein, Gabriele M. AU - Colombo, Gloria AU - Casado Polanco, Raquel AU - Siegert, Sandra ID - 10655 JF - Molecular Therapy - Methods and Clinical Development TI - Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment VL - 23 ER - TY - JOUR AB - Mosaic analysis with double markers (MADM) technology enables the generation of genetic mosaic tissue in mice. MADM enables concomitant fluorescent cell labeling and introduction of a mutation of a gene of interest with single-cell resolution. This protocol highlights major steps for the generation of genetic mosaic tissue and the isolation and processing of respective tissues for downstream histological analysis. For complete details on the use and execution of this protocol, please refer to Contreras et al. (2021). AU - Amberg, Nicole AU - Hippenmeyer, Simon ID - 10321 IS - 4 JF - STAR Protocols TI - Genetic mosaic dissection of candidate genes in mice using mosaic analysis with double markers VL - 2 ER - TY - JOUR AB - The synaptotrophic hypothesis posits that synapse formation stabilizes dendritic branches, yet this hypothesis has not been causally tested in vivo in the mammalian brain. Presynaptic ligand cerebellin-1 (Cbln1) and postsynaptic receptor GluD2 mediate synaptogenesis between granule cells and Purkinje cells in the molecular layer of the cerebellar cortex. Here we show that sparse but not global knockout of GluD2 causes under-elaboration of Purkinje cell dendrites in the deep molecular layer and overelaboration in the superficial molecular layer. Developmental, overexpression, structure-function, and genetic epistasis analyses indicate that dendrite morphogenesis defects result from competitive synaptogenesis in a Cbln1/GluD2-dependent manner. A generative model of dendritic growth based on competitive synaptogenesis largely recapitulates GluD2 sparse and global knockout phenotypes. Our results support the synaptotrophic hypothesis at initial stages of dendrite development, suggest a second mode in which cumulative synapse formation inhibits further dendrite growth, and highlight the importance of competition in dendrite morphogenesis. AU - Takeo, Yukari H. AU - Shuster, S. Andrew AU - Jiang, Linnie AU - Hu, Miley AU - Luginbuhl, David J. AU - Rülicke, Thomas AU - Contreras, Ximena AU - Hippenmeyer, Simon AU - Wagner, Mark J. AU - Ganguli, Surya AU - Luo, Liqun ID - 8544 IS - 4 JF - Neuron TI - GluD2- and Cbln1-mediated competitive synaptogenesis shapes the dendritic arbors of cerebellar Purkinje cells VL - 109 ER - TY - THES AB - The brain is one of the largest and most complex organs and it is composed of billions of neurons that communicate together enabling e.g. consciousness. The cerebral cortex is the largest site of neural integration in the central nervous system. Concerted radial migration of newly born cortical projection neurons, from their birthplace to their final position, is a key step in the assembly of the cerebral cortex. The cellular and molecular mechanisms regulating radial neuronal migration in vivo are however still unclear. Recent evidence suggests that distinct signaling cues act cell-autonomously but differentially at certain steps during the overall migration process. Moreover, functional analysis of genetic mosaics (mutant neurons present in wild-type/heterozygote environment) using the MADM (Mosaic Analysis with Double Markers) analyses in comparison to global knockout also indicate a significant degree of non-cell-autonomous and/or community effects in the control of cortical neuron migration. The interactions of cell-intrinsic (cell-autonomous) and cell-extrinsic (non-cell-autonomous) components are largely unknown. In part of this thesis work we established a MADM-based experimental strategy for the quantitative analysis of cell-autonomous gene function versus non-cell-autonomous and/or community effects. The direct comparison of mutant neurons from the genetic mosaic (cell-autonomous) to mutant neurons in the conditional and/or global knockout (cell-autonomous + non-cell-autonomous) allows to quantitatively analyze non-cell-autonomous effects. Such analysis enable the high-resolution analysis of projection neuron migration dynamics in distinct environments with concomitant isolation of genomic and proteomic profiles. Using these experimental paradigms and in combination with computational modeling we show and characterize the nature of non-cell-autonomous effects to coordinate radial neuron migration. Furthermore, this thesis discusses recent developments in neurodevelopment with focus on neuronal polarization and non-cell-autonomous mechanisms in neuronal migration. AU - Hansen, Andi H ID - 9962 KW - Neuronal migration KW - Non-cell-autonomous KW - Cell-autonomous KW - Neurodevelopmental disease SN - 2663-337X TI - Cell-autonomous gene function and non-cell-autonomous effects in radial projection neuron migration ER - TY - JOUR AB - Scientific research is to date largely restricted to wealthy laboratories in developed nations due to the necessity of complex and expensive equipment. This inequality limits the capacity of science to be used as a diplomatic channel. Maker movements use open-source technologies including additive manufacturing (3D printing) and laser cutting, together with low-cost computers for developing novel products. This movement is setting the groundwork for a revolution, allowing scientific equipment to be sourced at a fraction of the cost and has the potential to increase the availability of equipment for scientists around the world. Science education is increasingly recognized as another channel for science diplomacy. In this perspective, we introduce the idea that the Maker movement and open-source technologies have the potential to revolutionize science, technology, engineering and mathematics (STEM) education worldwide. We present an open-source STEM didactic tool called SCOPES (Sparking Curiosity through Open-source Platforms in Education and Science). SCOPES is self-contained, independent of local resources, and cost-effective. SCOPES can be adapted to communicate complex subjects from genetics to neurobiology, perform real-world biological experiments and explore digitized scientific samples. We envision such platforms will enhance science diplomacy by providing a means for scientists to share their findings with classrooms and for educators to incorporate didactic concepts into STEM lessons. By providing students the opportunity to design, perform, and share scientific experiments, students also experience firsthand the benefits of a multinational scientific community. We provide instructions on how to build and use SCOPES on our webpage: http://scopeseducation.org. AU - Beattie, Robert J AU - Hippenmeyer, Simon AU - Pauler, Florian ID - 7814 JF - Frontiers in Education SN - 2504-284X TI - SCOPES: Sparking curiosity through Open-Source platforms in education and science VL - 5 ER - TY - GEN AB - The brain vasculature supplies neurons with glucose and oxygen, but little is known about how vascular plasticity contributes to brain function. Using longitudinal in vivo imaging, we reported that a substantial proportion of blood vessels in the adult brain sporadically occluded and regressed. Their regression proceeded through sequential stages of blood-flow occlusion, endothelial cell collapse, relocation or loss of pericytes, and retraction of glial endfeet. Regressing vessels were found to be widespread in mouse, monkey and human brains. Both brief occlusions of the middle cerebral artery and lipopolysaccharide-mediated inflammation induced an increase of vessel regression. Blockage of leukocyte adhesion to endothelial cells alleviated LPS-induced vessel regression. We further revealed that blood vessel regression caused a reduction of neuronal activity due to a dysfunction in mitochondrial metabolism and glutamate production. Our results elucidate the mechanism of vessel regression and its role in neuronal function in the adult brain. AU - Gao, Xiaofei AU - Li, Jun-Liszt AU - Chen, Xingjun AU - Ci, Bo AU - Chen, Fei AU - Lu, Nannan AU - Shen, Bo AU - Zheng, Lijun AU - Jia, Jie-Min AU - Yi, Yating AU - Zhang, Shiwen AU - Shi, Ying-Chao AU - Shi, Kaibin AU - Propson, Nicholas E AU - Huang, Yubin AU - Poinsatte, Katherine AU - Zhang, Zhaohuan AU - Yue, Yuanlei AU - Bosco, Dale B AU - Lu, Ying-mei AU - Yang, Shi-bing AU - Adams, Ralf H. AU - Lindner, Volkhard AU - Huang, Fen AU - Wu, Long-Jun AU - Zheng, Hui AU - Han, Feng AU - Hippenmeyer, Simon AU - Stowe, Ann M. AU - Peng, Bo AU - Margeta, Marta AU - Wang, Xiaoqun AU - Liu, Qiang AU - Körbelin, Jakob AU - Trepel, Martin AU - Lu, Hui AU - Zhou, Bo O. AU - Zhao, Hu AU - Su, Wenzhi AU - Bachoo, Robert M. AU - Ge, Woo-ping ID - 8616 T2 - bioRxiv TI - Reduction of neuronal activity mediated by blood-vessel regression in the brain ER - TY - JOUR AB - Mosaic analysis with double markers (MADM) technology enables concomitant fluorescent cell labeling and induction of uniparental chromosome disomy (UPD) with single-cell resolution. In UPD, imprinted genes are either overexpressed 2-fold or are not expressed. Here, the MADM platform is utilized to probe imprinting phenotypes at the transcriptional level. This protocol highlights major steps for the generation and isolation of projection neurons and astrocytes with MADM-induced UPD from mouse cerebral cortex for downstream single-cell and low-input sample RNA-sequencing experiments. For complete details on the use and execution of this protocol, please refer to Laukoter et al. (2020b). AU - Laukoter, Susanne AU - Amberg, Nicole AU - Pauler, Florian AU - Hippenmeyer, Simon ID - 8978 IS - 3 JF - STAR Protocols SN - 2666-1667 TI - Generation and isolation of single cells from mouse brain with mosaic analysis with double markers-induced uniparental chromosome disomy VL - 1 ER - TY - JOUR AB - The cyclin-dependent kinase inhibitor p57KIP2 is encoded by the imprinted Cdkn1c locus, exhibits maternal expression, and is essential for cerebral cortex development. How Cdkn1c regulates corticogenesis is however not clear. To this end we employ Mosaic Analysis with Double Markers (MADM) technology to genetically dissect Cdkn1c gene function in corticogenesis at single cell resolution. We find that the previously described growth-inhibitory Cdkn1c function is a non-cell-autonomous one, acting on the whole organism. In contrast we reveal a growth-promoting cell-autonomous Cdkn1c function which at the mechanistic level mediates radial glial progenitor cell and nascent projection neuron survival. Strikingly, the growth-promoting function of Cdkn1c is highly dosage sensitive but not subject to genomic imprinting. Collectively, our results suggest that the Cdkn1c locus regulates cortical development through distinct cell-autonomous and non-cell-autonomous mechanisms. More generally, our study highlights the importance to probe the relative contributions of cell intrinsic gene function and tissue-wide mechanisms to the overall phenotype. AU - Laukoter, Susanne AU - Beattie, Robert J AU - Pauler, Florian AU - Amberg, Nicole AU - Nakayama, Keiichi I. AU - Hippenmeyer, Simon ID - 7253 JF - Nature Communications SN - 2041-1723 TI - Imprinted Cdkn1c genomic locus cell-autonomously promotes cell survival in cerebral cortex development VL - 11 ER - TY - JOUR AB - Heterozygous loss of human PAFAH1B1 (coding for LIS1) results in the disruption of neurogenesis and neuronal migration via dysregulation of microtubule (MT) stability and dynein motor function/localization that alters mitotic spindle orientation, chromosomal segregation, and nuclear migration. Recently, human induced pluripotent stem cell (iPSC) models revealed an important role for LIS1 in controlling the length of terminal cell divisions of outer radial glial (oRG) progenitors, suggesting cellular functions of LIS1 in regulating neural progenitor cell (NPC) daughter cell separation. Here we examined the late mitotic stages NPCs in vivo and mouse embryonic fibroblasts (MEFs) in vitro from Pafah1b1-deficient mutants. Pafah1b1-deficient neocortical NPCs and MEFs similarly exhibited cleavage plane displacement with mislocalization of furrow-associated markers, associated with actomyosin dysfunction and cell membrane hyper-contractility. Thus, it suggests LIS1 acts as a key molecular link connecting MTs/dynein and actomyosin, ensuring that cell membrane contractility is tightly controlled to execute proper daughter cell separation. AU - Moon, Hyang Mi AU - Hippenmeyer, Simon AU - Luo, Liqun AU - Wynshaw-Boris, Anthony ID - 7593 JF - eLife SN - 2050-084X TI - LIS1 determines cleavage plane positioning by regulating actomyosin-mediated cell membrane contractility VL - 9 ER - TY - JOUR AB - Background: The activation of the EGFR/Ras-signalling pathway in tumour cells induces a distinct chemokine repertoire, which in turn modulates the tumour microenvironment. Methods: The effects of EGFR/Ras on the expression and translation of CCL20 were analysed in a large set of epithelial cancer cell lines and tumour tissues by RT-qPCR and ELISA in vitro. CCL20 production was verified by immunohistochemistry in different tumour tissues and correlated with clinical data. The effects of CCL20 on endothelial cell migration and tumour-associated vascularisation were comprehensively analysed with chemotaxis assays in vitro and in CCR6-deficient mice in vivo. Results: Tumours facilitate progression by the EGFR/Ras-induced production of CCL20. Expression of the chemokine CCL20 in tumours correlates with advanced tumour stage, increased lymph node metastasis and decreased survival in patients. Microvascular endothelial cells abundantly express the specific CCL20 receptor CCR6. CCR6 signalling in endothelial cells induces angiogenesis. CCR6-deficient mice show significantly decreased tumour growth and tumour-associated vascularisation. The observed phenotype is dependent on CCR6 deficiency in stromal cells but not within the immune system. Conclusion: We propose that the chemokine axis CCL20–CCR6 represents a novel and promising target to interfere with the tumour microenvironment, and opens an innovative multimodal strategy for cancer therapy. AU - Hippe, Andreas AU - Braun, Stephan Alexander AU - Oláh, Péter AU - Gerber, Peter Arne AU - Schorr, Anne AU - Seeliger, Stephan AU - Holtz, Stephanie AU - Jannasch, Katharina AU - Pivarcsi, Andor AU - Buhren, Bettina AU - Schrumpf, Holger AU - Kislat, Andreas AU - Bünemann, Erich AU - Steinhoff, Martin AU - Fischer, Jens AU - Lira, Sérgio A. AU - Boukamp, Petra AU - Hevezi, Peter AU - Stoecklein, Nikolas Hendrik AU - Hoffmann, Thomas AU - Alves, Frauke AU - Sleeman, Jonathan AU - Bauer, Thomas AU - Klufa, Jörg AU - Amberg, Nicole AU - Sibilia, Maria AU - Zlotnik, Albert AU - Müller-Homey, Anja AU - Homey, Bernhard ID - 8093 JF - British Journal of Cancer SN - 0007-0920 TI - EGFR/Ras-induced CCL20 production modulates the tumour microenvironment VL - 123 ER - TY - JOUR AB - In mammalian genomes, a subset of genes is regulated by genomic imprinting, resulting in silencing of one parental allele. Imprinting is essential for cerebral cortex development, but prevalence and functional impact in individual cells is unclear. Here, we determined allelic expression in cortical cell types and established a quantitative platform to interrogate imprinting in single cells. We created cells with uniparental chromosome disomy (UPD) containing two copies of either the maternal or the paternal chromosome; hence, imprinted genes will be 2-fold overexpressed or not expressed. By genetic labeling of UPD, we determined cellular phenotypes and transcriptional responses to deregulated imprinted gene expression at unprecedented single-cell resolution. We discovered an unexpected degree of cell-type specificity and a novel function of imprinting in the regulation of cortical astrocyte survival. More generally, our results suggest functional relevance of imprinted gene expression in glial astrocyte lineage and thus for generating cortical cell-type diversity. AU - Laukoter, Susanne AU - Pauler, Florian AU - Beattie, Robert J AU - Amberg, Nicole AU - Hansen, Andi H AU - Streicher, Carmen AU - Penz, Thomas AU - Bock, Christoph AU - Hippenmeyer, Simon ID - 8162 IS - 6 JF - Neuron SN - 0896-6273 TI - Cell-type specificity of genomic imprinting in cerebral cortex VL - 107 ER - TY - JOUR AB - Glioblastoma is the most malignant cancer in the brain and currently incurable. It is urgent to identify effective targets for this lethal disease. Inhibition of such targets should suppress the growth of cancer cells and, ideally also precancerous cells for early prevention, but minimally affect their normal counterparts. Using genetic mouse models with neural stem cells (NSCs) or oligodendrocyte precursor cells (OPCs) as the cells‐of‐origin/mutation, it is shown that the susceptibility of cells within the development hierarchy of glioma to the knockout of insulin‐like growth factor I receptor (IGF1R) is determined not only by their oncogenic states, but also by their cell identities/states. Knockout of IGF1R selectively disrupts the growth of mutant and transformed, but not normal OPCs, or NSCs. The desirable outcome of IGF1R knockout on cell growth requires the mutant cells to commit to the OPC identity regardless of its development hierarchical status. At the molecular level, oncogenic mutations reprogram the cellular network of OPCs and force them to depend more on IGF1R for their growth. A new‐generation brain‐penetrable, orally available IGF1R inhibitor harnessing tumor OPCs in the brain is also developed. The findings reveal the cellular window of IGF1R targeting and establish IGF1R as an effective target for the prevention and treatment of glioblastoma. AU - Tian, Anhao AU - Kang, Bo AU - Li, Baizhou AU - Qiu, Biying AU - Jiang, Wenhong AU - Shao, Fangjie AU - Gao, Qingqing AU - Liu, Rui AU - Cai, Chengwei AU - Jing, Rui AU - Wang, Wei AU - Chen, Pengxiang AU - Liang, Qinghui AU - Bao, Lili AU - Man, Jianghong AU - Wang, Yan AU - Shi, Yu AU - Li, Jin AU - Yang, Minmin AU - Wang, Lisha AU - Zhang, Jianmin AU - Hippenmeyer, Simon AU - Zhu, Junming AU - Bian, Xiuwu AU - Wang, Ying‐Jie AU - Liu, Chong ID - 8592 IS - 21 JF - Advanced Science KW - General Engineering KW - General Physics and Astronomy KW - General Materials Science KW - Medicine (miscellaneous) KW - General Chemical Engineering KW - Biochemistry KW - Genetics and Molecular Biology (miscellaneous) SN - 2198-3844 TI - Oncogenic state and cell identity combinatorially dictate the susceptibility of cells within glioma development hierarchy to IGF1R targeting VL - 7 ER -