@article{11336, abstract = {The generation of a correctly-sized cerebral cortex with all-embracing neuronal and glial cell-type diversity critically depends on faithful radial glial progenitor (RGP) cell proliferation/differentiation programs. Temporal RGP lineage progression is regulated by Polycomb Repressive Complex 2 (PRC2) and loss of PRC2 activity results in severe neurogenesis defects and microcephaly. How PRC2-dependent gene expression instructs RGP lineage progression is unknown. Here we utilize Mosaic Analysis with Double Markers (MADM)-based single cell technology and demonstrate that PRC2 is not cell-autonomously required in neurogenic RGPs but rather acts at the global tissue-wide level. Conversely, cortical astrocyte production and maturation is cell-autonomously controlled by PRC2-dependent transcriptional regulation. We thus reveal highly distinct and sequential PRC2 functions in RGP lineage progression that are dependent on complex interplays between intrinsic and tissue-wide properties. In a broader context our results imply a critical role for the genetic and cellular niche environment in neural stem cell behavior.}, author = {Amberg, Nicole and Pauler, Florian and Streicher, Carmen and Hippenmeyer, Simon}, issn = {2375-2548}, journal = {Science Advances}, number = {44}, publisher = {American Association for the Advancement of Science}, title = {{Tissue-wide genetic and cellular landscape shapes the execution of sequential PRC2 functions in neural stem cell lineage progression}}, doi = {10.1126/sciadv.abq1263}, volume = {8}, year = {2022}, } @article{9794, abstract = {Lymph nodes (LNs) comprise two main structural elements: fibroblastic reticular cells that form dedicated niches for immune cell interaction and capsular fibroblasts that build a shell around the organ. Immunological challenge causes LNs to increase more than tenfold in size within a few days. Here, we characterized the biomechanics of LN swelling on the cellular and organ scale. We identified lymphocyte trapping by influx and proliferation as drivers of an outward pressure force, causing fibroblastic reticular cells of the T-zone (TRCs) and their associated conduits to stretch. After an initial phase of relaxation, TRCs sensed the resulting strain through cell matrix adhesions, which coordinated local growth and remodeling of the stromal network. While the expanded TRC network readopted its typical configuration, a massive fibrotic reaction of the organ capsule set in and countered further organ expansion. Thus, different fibroblast populations mechanically control LN swelling in a multitier fashion.}, author = {Assen, Frank P and Abe, Jun and Hons, Miroslav and Hauschild, Robert and Shamipour, Shayan and Kaufmann, Walter and Costanzo, Tommaso and Krens, Gabriel and Brown, Markus and Ludewig, Burkhard and Hippenmeyer, Simon and Heisenberg, Carl-Philipp J and Weninger, Wolfgang and Hannezo, Edouard B and Luther, Sanjiv A. and Stein, Jens V. and Sixt, Michael K}, issn = {1529-2916}, journal = {Nature Immunology}, pages = {1246--1255}, publisher = {Springer Nature}, title = {{Multitier mechanics control stromal adaptations in swelling lymph nodes}}, doi = {10.1038/s41590-022-01257-4}, volume = {23}, year = {2022}, } @article{10764, abstract = {Presynaptic glutamate replenishment is fundamental to brain function. In high activity regimes, such as epileptic episodes, this process is thought to rely on the glutamate-glutamine cycle between neurons and astrocytes. However the presence of an astroglial glutamine supply, as well as its functional relevance in vivo in the healthy brain remain controversial, partly due to a lack of tools that can directly examine glutamine transfer. Here, we generated a fluorescent probe that tracks glutamine in live cells, which provides direct visual evidence of an activity-dependent glutamine supply from astroglial networks to presynaptic structures under physiological conditions. This mobilization is mediated by connexin43, an astroglial protein with both gap-junction and hemichannel functions, and is essential for synaptic transmission and object recognition memory. Our findings uncover an indispensable recruitment of astroglial glutamine in physiological synaptic activity and memory via an unconventional pathway, thus providing an astrocyte basis for cognitive processes.}, author = {Cheung, Giselle T and Bataveljic, Danijela and Visser, Josien and Kumar, Naresh and Moulard, Julien and Dallérac, Glenn and Mozheiko, Daria and Rollenhagen, Astrid and Ezan, Pascal and Mongin, Cédric and Chever, Oana and Bemelmans, Alexis Pierre and Lübke, Joachim and Leray, Isabelle and Rouach, Nathalie}, issn = {20411723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Physiological synaptic activity and recognition memory require astroglial glutamine}}, doi = {10.1038/s41467-022-28331-7}, volume = {13}, year = {2022}, } @article{11460, abstract = {Background: Proper cerebral cortical development depends on the tightly orchestrated migration of newly born neurons from the inner ventricular and subventricular zones to the outer cortical plate. Any disturbance in this process during prenatal stages may lead to neuronal migration disorders (NMDs), which can vary in extent from focal to global. Furthermore, NMDs show a substantial comorbidity with other neurodevelopmental disorders, notably autism spectrum disorders (ASDs). Our previous work demonstrated focal neuronal migration defects in mice carrying loss-of-function alleles of the recognized autism risk gene WDFY3. However, the cellular origins of these defects in Wdfy3 mutant mice remain elusive and uncovering it will provide critical insight into WDFY3-dependent disease pathology. Methods: Here, in an effort to untangle the origins of NMDs in Wdfy3lacZ mice, we employed mosaic analysis with double markers (MADM). MADM technology enabled us to genetically distinctly track and phenotypically analyze mutant and wild-type cells concomitantly in vivo using immunofluorescent techniques. Results: We revealed a cell autonomous requirement of WDFY3 for accurate laminar positioning of cortical projection neurons and elimination of mispositioned cells during early postnatal life. In addition, we identified significant deviations in dendritic arborization, as well as synaptic density and morphology between wild type, heterozygous, and homozygous Wdfy3 mutant neurons in Wdfy3-MADM reporter mice at postnatal stages. Limitations: While Wdfy3 mutant mice have provided valuable insight into prenatal aspects of ASD pathology that remain inaccessible to investigation in humans, like most animal models, they do not a perfectly replicate all aspects of human ASD biology. The lack of human data makes it indeterminate whether morphological deviations described here apply to ASD patients or some of the other neurodevelopmental conditions associated with WDFY3 mutation. Conclusions: Our genetic approach revealed several cell autonomous requirements of WDFY3 in neuronal development that could underlie the pathogenic mechanisms of WDFY3-related neurodevelopmental conditions. The results are also consistent with findings in other ASD animal models and patients and suggest an important role for WDFY3 in regulating neuronal function and interconnectivity in postnatal life.}, author = {Schaaf, Zachary A. and Tat, Lyvin and Cannizzaro, Noemi and Green, Ralph and Rülicke, Thomas and Hippenmeyer, Simon and Zarbalis, Konstantinos S.}, issn = {2040-2392}, journal = {Molecular Autism}, keywords = {Psychiatry and Mental health, Developmental Biology, Developmental Neuroscience, Molecular Biology}, publisher = {Springer Nature}, title = {{WDFY3 mutation alters laminar position and morphology of cortical neurons}}, doi = {10.1186/s13229-022-00508-3}, volume = {13}, year = {2022}, } @article{11449, abstract = {Mutations are acquired frequently, such that each cell's genome inscribes its history of cell divisions. Common genomic alterations involve loss of heterozygosity (LOH). LOH accumulates throughout the genome, offering large encoding capacity for inferring cell lineage. Using only single-cell RNA sequencing (scRNA-seq) of mouse brain cells, we found that LOH events spanning multiple genes are revealed as tracts of monoallelically expressed, constitutionally heterozygous single-nucleotide variants (SNVs). We simultaneously inferred cell lineage and marked developmental time points based on X chromosome inactivation and the total number of LOH events while identifying cell types from gene expression patterns. Our results are consistent with progenitor cells giving rise to multiple cortical cell types through stereotyped expansion and distinct waves of neurogenesis. This type of retrospective analysis could be incorporated into scRNA-seq pipelines and, compared with experimental approaches for determining lineage in model organisms, is applicable where genetic engineering is prohibited, such as humans.}, author = {Anderson, Donovan J. and Pauler, Florian and Mckenna, Aaron and Shendure, Jay and Hippenmeyer, Simon and Horwitz, Marshall S.}, issn = {2405-4720}, journal = {Cell Systems}, number = {6}, pages = {438--453.e5}, publisher = {Elsevier}, title = {{Simultaneous brain cell type and lineage determined by scRNA-seq reveals stereotyped cortical development}}, doi = {10.1016/j.cels.2022.03.006}, volume = {13}, year = {2022}, } @article{12283, abstract = {Neurons extend axons to form the complex circuitry of the mature brain. This depends on the coordinated response and continuous remodelling of the microtubule and F-actin networks in the axonal growth cone. Growth cone architecture remains poorly understood at nanoscales. We therefore investigated mouse hippocampal neuron growth cones using cryo-electron tomography to directly visualise their three-dimensional subcellular architecture with molecular detail. Our data showed that the hexagonal arrays of actin bundles that form filopodia penetrate and terminate deep within the growth cone interior. We directly observed the modulation of these and other growth cone actin bundles by alteration of individual F-actin helical structures. Microtubules with blunt, slightly flared or gently curved ends predominated in the growth cone, frequently contained lumenal particles and exhibited lattice defects. Investigation of the effect of absence of doublecortin, a neurodevelopmental cytoskeleton regulator, on growth cone cytoskeleton showed no major anomalies in overall growth cone organisation or in F-actin subpopulations. However, our data suggested that microtubules sustained more structural defects, highlighting the importance of microtubule integrity during growth cone migration.}, author = {Atherton, Joseph and Stouffer, Melissa A and Francis, Fiona and Moores, Carolyn A.}, issn = {1477-9137}, journal = {Journal of Cell Science}, keywords = {Cell Biology}, number = {7}, publisher = {The Company of Biologists}, title = {{Visualising the cytoskeletal machinery in neuronal growth cones using cryo-electron tomography}}, doi = {10.1242/jcs.259234}, volume = {135}, year = {2022}, } @article{12282, abstract = {From a simple thought to a multicellular movement}, author = {Amberg, Nicole and Stouffer, Melissa A and Vercellino, Irene}, issn = {1477-9137}, journal = {Journal of Cell Science}, number = {8}, publisher = {The Company of Biologists}, title = {{Operation STEM fatale – how an equity, diversity and inclusion initiative has brought us to reflect on the current challenges in cell biology and science as a whole}}, doi = {10.1242/jcs.260017}, volume = {135}, year = {2022}, } @unpublished{10792, abstract = {Background Proper cerebral cortical development depends on the tightly orchestrated migration of newly born neurons from the inner ventricular and subventricular zones to the outer cortical plate. Any disturbance in this process during prenatal stages may lead to neuronal migration disorders (NMDs), which can vary in extent from focal to global. Furthermore, NMDs show a substantial comorbidity with other neurodevelopmental disorders, notably autism spectrum disorders (ASDs). Our previous work demonstrated focal neuronal migration defects in mice carrying loss-of-function alleles of the recognized autism risk gene WDFY3. However, the cellular origins of these defects in Wdfy3 mutant mice remain elusive and uncovering it will provide critical insight into WDFY3-dependent disease pathology . Methods Here, in an effort to untangle the origins of NMDs in Wdfy3lacZ mice, we employed mosaic analysis with double markers (MADM). MADM technology enabled us to genetically distinctly track and phenotypically analyze mutant and wild type cells concomitantly in vivo using immunofluorescent techniques. Results We revealed a cell autonomous requirement of WDFY3 for accurate laminar positioning of cortical projection neurons and elimination of mispositioned cells during early postnatal life. In addition, we identified significant deviations in dendritic arborization, as well as synaptic density and morphology between wild type, heterozygous, and homozygous Wdfy3 mutant neurons in Wdfy3-MADM reporter mice at postnatal stages. Limitations While Wdfy3 mutant mice have provided valuable insight into prenatal aspects of ASD pathology that remain inaccessible to investigation in humans, like most animal models, they do not a perfectly replicate all aspects of human ASD biology. The lack of human data makes it indeterminate whether morphological deviations described here apply to ASD patients. Conclusions Our genetic approach revealed several cell autonomous requirements of Wdfy3 in neuronal development that could underly the pathogenic mechanisms of WDFY3-related ASD conditions. The results are also consistent with findings in other ASD animal models and patients and suggest an important role for Wdfy3 in regulating neuronal function and interconnectivity in postnatal life.}, author = {Schaaf, Zachary and Tat, Lyvin and Cannizzaro, Noemi and Green, Ralph and Rülicke, Thomas and Hippenmeyer, Simon and Zarbalis, K}, issn = {2693-5015}, pages = {30}, publisher = {Research Square}, title = {{WDFY3 cell autonomously controls neuronal migration}}, doi = {10.21203/rs.3.rs-1316167/v1}, year = {2022}, } @article{10791, abstract = {The mammalian neocortex is composed of diverse neuronal and glial cell classes that broadly arrange in six distinct laminae. Cortical layers emerge during development and defects in the developmental programs that orchestrate cortical lamination are associated with neurodevelopmental diseases. The developmental principle of cortical layer formation depends on concerted radial projection neuron migration, from their birthplace to their final target position. Radial migration occurs in defined sequential steps, regulated by a large array of signaling pathways. However, based on genetic loss-of-function experiments, most studies have thus far focused on the role of cell-autonomous gene function. Yet, cortical neuron migration in situ is a complex process and migrating neurons traverse along diverse cellular compartments and environments. The role of tissue-wide properties and genetic state in radial neuron migration is however not clear. Here we utilized mosaic analysis with double markers (MADM) technology to either sparsely or globally delete gene function, followed by quantitative single-cell phenotyping. The MADM-based gene ablation paradigms in combination with computational modeling demonstrated that global tissue-wide effects predominate cell-autonomous gene function albeit in a gene-specific manner. Our results thus suggest that the genetic landscape in a tissue critically affects the overall migration phenotype of individual cortical projection neurons. In a broader context, our findings imply that global tissue-wide effects represent an essential component of the underlying etiology associated with focal malformations of cortical development in particular, and neurological diseases in general.}, author = {Hansen, Andi H and Pauler, Florian and Riedl, Michael and Streicher, Carmen and Heger, Anna-Magdalena and Laukoter, Susanne and Sommer, Christoph M and Nicolas, Armel and Hof, Björn and Tsai, Li Huei and Rülicke, Thomas and Hippenmeyer, Simon}, issn = {2753-149X}, journal = {Oxford Open Neuroscience}, number = {1}, publisher = {Oxford Academic}, title = {{Tissue-wide effects override cell-intrinsic gene function in radial neuron migration}}, doi = {10.1093/oons/kvac009}, volume = {1}, year = {2022}, } @unpublished{9082, abstract = {Acquired mutations are sufficiently frequent such that the genome of a single cell offers a record of its history of cell divisions. Among more common somatic genomic alterations are loss of heterozygosity (LOH). Large LOH events are potentially detectable in single cell RNA sequencing (scRNA-seq) datasets as tracts of monoallelic expression for constitutionally heterozygous single nucleotide variants (SNVs) located among contiguous genes. We identified runs of monoallelic expression, consistent with LOH, uniquely distributed throughout the genome in single cell brain cortex transcriptomes of F1 hybrids involving different inbred mouse strains. We then phylogenetically reconstructed single cell lineages and simultaneously identified cell types by corresponding gene expression patterns. Our results are consistent with progenitor cells giving rise to multiple cortical cell types through stereotyped expansion and distinct waves of neurogenesis. Compared to engineered recording systems, LOH events accumulate throughout the genome and across the lifetime of an organism, affording tremendous capacity for encoding lineage information and increasing resolution for later cell divisions. This approach can conceivably be computationally incorporated into scRNA-seq analysis and may be useful for organisms where genetic engineering is prohibitive, such as humans.}, author = {Anderson, Donovan J. and Pauler, Florian and McKenna, Aaron and Shendure, Jay and Hippenmeyer, Simon and Horwitz, Marshall S.}, booktitle = {bioRxiv}, publisher = {Cold Spring Harbor Laboratory}, title = {{Simultaneous identification of brain cell type and lineage via single cell RNA sequencing}}, doi = {10.1101/2020.12.31.425016}, year = {2021}, } @misc{6995, abstract = {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.}, author = {Samarasinghe, Ranmal A. and Miranda, Osvaldo and Buth, Jessie E. and Mitchell, Simon and Ferando, Isabella and Watanabe, Momoko and Kurdian, Arinnae and Golshani, Peyman and Plath, Kathrin and Lowry, William E. and Parent, Jack M. and Mody, Istvan and Novitch, Bennett G.}, issn = {1546-1726}, pages = {32}, publisher = {Springer Nature}, title = {{Identification of neural oscillations and epileptiform changes in human brain organoids}}, doi = {10.1038/s41593-021-00906-5}, volume = {24}, year = {2021}, } @article{8546, abstract = {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.}, author = {Zhang, Tingting and Liu, Tengyuan and Mora, Natalia and Guegan, Justine and Bertrand, Mathilde and Contreras, Ximena and Hansen, Andi H and Streicher, Carmen and Anderle, Marica and Danda, Natasha and Tiberi, Luca and Hippenmeyer, Simon and Hassan, Bassem A.}, issn = { 22111247}, journal = {Cell Reports}, number = {10}, publisher = {Elsevier}, title = {{Generation of excitatory and inhibitory neurons from common progenitors via Notch signaling in the cerebellum}}, doi = {10.1016/j.celrep.2021.109208}, volume = {35}, year = {2021}, } @article{9188, abstract = {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.}, author = {Pauler, Florian and Hudson, Quanah and Laukoter, Susanne and Hippenmeyer, Simon}, issn = {0197-0186}, journal = {Neurochemistry International}, keywords = {Cell Biology, Cellular and Molecular Neuroscience}, number = {5}, publisher = {Elsevier}, title = {{Inducible uniparental chromosome disomy to probe genomic imprinting at single-cell level in brain and beyond}}, doi = {10.1016/j.neuint.2021.104986}, volume = {145}, year = {2021}, } @article{9601, abstract = {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.}, author = {Santini, Laura and Halbritter, Florian and Titz-Teixeira, Fabian and Suzuki, Toru and Asami, Maki and Ma, Xiaoyan and Ramesmayer, Julia and Lackner, Andreas and Warr, Nick and Pauler, Florian and Hippenmeyer, Simon and Laue, Ernest and Farlik, Matthias and Bock, Christoph and Beyer, Andreas and Perry, Anthony C.F. and Leeb, Martin}, issn = {20411723}, journal = {Nature Communications}, number = {1}, publisher = {Springer Nature}, title = {{Genomic imprinting in mouse blastocysts is predominantly associated with H3K27me3}}, doi = {10.1038/s41467-021-23510-4}, volume = {12}, year = {2021}, } @article{9603, abstract = {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.}, author = {Contreras, Ximena and Amberg, Nicole and Davaatseren, Amarbayasgalan and Hansen, Andi H and Sonntag, Johanna and Andersen, Lill and Bernthaler, Tina and Streicher, Carmen and Heger, Anna-Magdalena and Johnson, Randy L. and Schwarz, Lindsay A. and Luo, Liqun and Rülicke, Thomas and Hippenmeyer, Simon}, issn = {22111247}, journal = {Cell Reports}, number = {12}, publisher = {Cell Press}, title = {{A genome-wide library of MADM mice for single-cell genetic mosaic analysis}}, doi = {10.1016/j.celrep.2021.109274}, volume = {35}, year = {2021}, } @article{9906, abstract = {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.}, author = {Yotova, Iveta and Hudson, Quanah J. and Pauler, Florian and Proestling, Katharina and Haslinger, Isabella and Kuessel, Lorenz and Perricos, Alexandra and Husslein, Heinrich and Wenzl, René}, issn = {14220067}, journal = {International Journal of Molecular Sciences}, number = {16}, publisher = {MDPI}, title = {{LINC01133 inhibits invasion and promotes proliferation in an endometriosis epithelial cell line}}, doi = {10.3390/ijms22168385}, volume = {22}, year = {2021}, } @article{9073, abstract = {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.}, author = {Hanganu-Opatz, Ileana L. and Butt, Simon J. B. and Hippenmeyer, Simon and De Marco García, Natalia V. and Cardin, Jessica A. and Voytek, Bradley and Muotri, Alysson R.}, issn = {1529-2401}, journal = {The Journal of Neuroscience}, keywords = {General Neuroscience}, number = {5}, pages = {813--822}, publisher = {Society for Neuroscience}, title = {{The logic of developing neocortical circuits in health and disease}}, doi = {10.1523/jneurosci.1655-20.2020}, volume = {41}, year = {2021}, } @article{9793, abstract = {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.}, author = {Baldwin, Katherine T. and Tan, Christabel X. and Strader, Samuel T. and Jiang, Changyu and Savage, Justin T. and Elorza-Vidal, Xabier and Contreras, Ximena and Rülicke, Thomas and Hippenmeyer, Simon and Estévez, Raúl and Ji, Ru-Rong and Eroglu, Cagla}, issn = {1097-4199}, journal = {Neuron}, number = {15}, pages = {2427--2442.e10}, publisher = {Elsevier}, title = {{HepaCAM controls astrocyte self-organization and coupling}}, doi = {10.1016/j.neuron.2021.05.025}, volume = {109}, year = {2021}, } @article{10655, abstract = {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. }, author = {Maes, Margaret E and Wögenstein, Gabriele M. and Colombo, Gloria and Casado Polanco, Raquel and Siegert, Sandra}, issn = {2329-0501}, journal = {Molecular Therapy - Methods and Clinical Development}, pages = {210--224}, publisher = {Elsevier}, title = {{Optimizing AAV2/6 microglial targeting identified enhanced efficiency in the photoreceptor degenerative environment}}, doi = {10.1016/j.omtm.2021.09.006}, volume = {23}, year = {2021}, } @article{10321, abstract = {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).}, author = {Amberg, Nicole and Hippenmeyer, Simon}, issn = {2666-1667}, journal = {STAR Protocols}, number = {4}, publisher = {Cell Press}, title = {{Genetic mosaic dissection of candidate genes in mice using mosaic analysis with double markers}}, doi = {10.1016/j.xpro.2021.100939}, volume = {2}, year = {2021}, }