Publications

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28 Publications visible to you, out of a total of 28

Abstract (Expand)

Hypothalamic astrocytes are particularly affected by energy-dense food consumption. How the anatomical location of these glial cells and their spatial molecular distribution in the arcuate nucleus of the hypothalamus (ARC) determine the cellular response to a high caloric diet remains unclear. In this study, we investigated their distinctive molecular responses following exposure to a high-fat high-sugar (HFHS) diet, specifically in the ARC. Using RNA sequencing and proteomics, we showed that astrocytes have a distinct transcriptomic and proteomic profile dependent on their anatomical location, with a major proteomic reprogramming in hypothalamic astrocytes. By ARC single-cell sequencing, we observed that a HFHS diet dictates time- and cell- specific transcriptomic responses, revealing that astrocytes have the most distinct regulatory pattern compared to other cell types. Lastly, we topographically and molecularly characterized astrocytes expressing glial fibrillary acidic protein and/or aldehyde dehydrogenase 1 family member L1 in the ARC, of which the abundance was significantly increased, as well as the alteration in their spatial and molecular profiles, with a HFHS diet. Together, our results provide a detailed multi-omics view on the spatial and temporal changes of astrocytes particularly in the ARC during different time points of adaptation to a high calorie diet.

Authors: Luiza Maria Lutomska, Viktorian Miok, Natalie Krahmer, Ismael González García, Tim Gruber, Ophélia Le Thuc, Cahuê Db Murat, Beata Legutko, Michael Sterr, Gesine Saher, Heiko Lickert, Timo D Müller, Siegfried Ussar, Matthias H Tschöp, Dominik Lutter, Cristina Garcia-Caceres

Date Published: 8th Jul 2022

Publication Type: Journal

Abstract (Expand)

The centrosome provides an intracellular anchor for the cytoskeleton, regulating cell division, cell migration, and cilia formation. We used spatial proteomics to elucidate protein interaction networks at the centrosome of human induced pluripotent stem cell-derived neural stem cells (NSCs) and neurons. Centrosome-associated proteins were largely cell type-specific, with protein hubs involved in RNA dynamics. Analysis of neurodevelopmental disease cohorts identified a significant overrepresentation of NSC centrosome proteins with variants in patients with periventricular heterotopia (PH). Expressing the PH-associated mutant pre-mRNA-processing factor 6 (PRPF6) reproduced the periventricular misplacement in the developing mouse brain, highlighting missplicing of transcripts of a microtubule-associated kinase with centrosomal location as essential for the phenotype. Collectively, cell type-specific centrosome interactomes explain how genetic variants in ubiquitous proteins may convey brain-specific phenotypes.

Authors: Adam C O'Neill, Fatma Uzbas, Giulia Antognolli, Florencia Merino, Kalina Draganova, Alex Jäck, Sirui Zhang, Giorgia Pedini, Julia P Schessner, Kimberly Cramer, Aloys Schepers, Fabian Metzger, Miriam Esgleas, Pawel Smialowski, Renzo Guerrini, Sven Falk, Regina Feederle, Saskia Freytag, Zefeng Wang, Melanie Bahlo, Ralf Jungmann, Claudia Bagni, Georg H H Borner, Stephen P Robertson, Stefanie M Hauck, Magdalena Götz

Date Published: 17th Jun 2022

Publication Type: Journal

Abstract (Expand)

Direct reprogramming based on genetic factors resembles a promising strategy to replace lost cells in degenerative diseases such as Parkinson's disease. For this, we developed a knock-in mouse line carrying a dual dCas9 transactivator system (dCAM) allowing the conditional in vivo activation of endogenous genes. To enable a translational application, we additionally established an AAV-based strategy carrying intein-split-dCas9 in combination with activators (AAV-dCAS). Both approaches were successful in reprogramming striatal astrocytes into induced GABAergic neurons confirmed by single-cell transcriptome analysis of reprogrammed neurons in vivo. These GABAergic neurons functionally integrate into striatal circuits, alleviating voluntary motor behavior aspects in a 6-OHDA Parkinson's disease model. Our results suggest a novel intervention strategy beyond the restoration of dopamine levels. Thus, the AAV-dCAS approach might enable an alternative route for clinical therapies of Parkinson's disease.

Authors: Jessica Giehrl-Schwab, Florian Giesert, Benedict Rauser, Chu Lan Lao, Sina Hembach, Sandrine Lefort, Ignacio L Ibarra, Christina Koupourtidou, Malte Daniel Luecken, Dong-Jiunn Jeffery Truong, Judith Fischer-Sternjak, Giacomo Masserdotti, Nilima Prakash, Jovica Ninkovic, Sabine M Hölter, Daniela M Vogt Weisenhorn, Fabian J Theis, Magdalena Götz, Wolfgang Wurst

Date Published: 9th May 2022

Publication Type: Journal

Abstract (Expand)

The oligodendrocyte progenitors (OPCs) are at the front of the glial reaction to the traumatic brain injury. However, regulatory pathways steering the OPC reaction as well as the role of reactive OPCs remain largely unknown. Here, we compared a long-lasting, exacerbated reaction of OPCs to the adult zebrafish brain injury with a timely restricted OPC activation to identify the specific molecular mechanisms regulating OPC reactivity and their contribution to regeneration. We demonstrated that the influx of the cerebrospinal fluid into the brain parenchyma after injury simultaneously activates the toll-like receptor 2 (Tlr2) and the chemokine receptor 3 (Cxcr3) innate immunity pathways, leading to increased OPC proliferation and thereby exacerbated glial reactivity. These pathways were critical for long-lasting OPC accumulation even after the ablation of microglia and infiltrating monocytes. Importantly, interference with the Tlr1/2 and Cxcr3 pathways after injury alleviated reactive gliosis, increased new neuron recruitment, and improved tissue restoration.

Authors: Rosario Sanchez-Gonzalez, Christina Koupourtidou, Tjasa Lepko, Alessandro Zambusi, Klara Tereza Novoselc, Tamara Durovic, Sven Aschenbroich, Veronika Schwarz, Christopher T Breunig, Hans Straka, Hagen B Huttner, Martin Irmler, Johannes Beckers, Wolfgang Wurst, Andreas Zwergal, Tamas Schauer, Tobias Straub, Tim Czopka, Dietrich Trümbach, Magdalena Götz, Stefan H Stricker, Jovica Ninkovic

Date Published: 2nd Feb 2022

Publication Type: Journal

Abstract (Expand)

Parkinson's disease (PD) is the second most common neurodegenerative disorder whose prevalence is rapidly increasing worldwide. The molecular mechanisms underpinning the pathophysiology of sporadic PD remain incompletely understood. Therefore, causative therapies are still elusive. To obtain a more integrative view of disease-mediated alterations, we investigated the molecular landscape of PD in human post-mortem midbrains, a region that is highly affected during the disease process.

Authors: Lucas Caldi Gomes, Ana Galhoz, Gaurav Jain, Anna-Elisa Roser, Fabian Maass, Eleonora Carboni, Elisabeth Barski, Christof Lenz, Katja Lohmann, Christine Klein, Mathias Bähr, André Fischer, Michael P Menden, Paul Lingor

Date Published: 28th Jan 2022

Publication Type: Journal

Abstract (Expand)

Astrocytes regulate brain-wide functions and also show region-specific differences, but little is known about how general and region-specific functions are aligned at the single-cell level. To explore this, we isolated adult mouse diencephalic astrocytes by ACSA-2-mediated magnetic-activated cell sorting (MACS). Single-cell RNA-seq revealed 7 gene expression clusters of astrocytes, with 4 forming a supercluster. Within the supercluster, cells differed by gene expression related to ion homeostasis or metabolism, with the former sharing gene expression with other regions and the latter being restricted to specific regions. All clusters showed expression of proliferation-related genes, and proliferation of diencephalic astrocytes was confirmed by immunostaining. Clonal analysis demonstrated low level of astrogenesis in the adult diencephalon, but not in cerebral cortex grey matter. This led to the identification of Smad4 as a key regulator of diencephalic astrocyte in vivo proliferation and in vitro neurosphere formation. Thus, astrocytes show diverse gene expression states related to distinct functions with some subsets being more widespread while others are more regionally restricted. However, all share low-level proliferation revealing the novel concept of adult astrogenesis in the diencephalon.

Authors: Stefanie Ohlig, Solène Clavreul, Manja Thorwirth, Tatiana Simon-Ebert, Riccardo Bocchi, Sabine Ulbricht, Nirmal Kannayian, Moritz Rossner, Swetlana Sirko, Pawel Smialowski, Judith Fischer-Sternjak, Magdalena Götz

Date Published: 2nd Nov 2021

Publication Type: Journal

Abstract (Expand)

Astrocytes are a viable source for generating new neurons via direct conversion. However, little is known about the neurogenic cascades triggered in astrocytes from different regions of the CNS. Here, we examine the transcriptome induced by the proneural factors Ascl1 and Neurog2 in spinal cord-derived astrocytes in vitro. Each factor initially elicits different neurogenic programs that later converge to a V2 interneuron-like state. Intriguingly, patch sequencing (patch-seq) shows no overall correlation between functional properties and the transcriptome of the heterogenous induced neurons, except for K-channels. For example, some neurons with fully mature electrophysiological properties still express astrocyte genes, thus calling for careful molecular and functional analysis. Comparing the transcriptomes of spinal cord- and cerebral-cortex-derived astrocytes reveals profound differences, including developmental patterning cues maintained in vitro. These relate to the distinct neuronal identity elicited by Ascl1 and Neurog2 reflecting their developmental functions in subtype specification of the respective CNS region.

Authors: J Kempf, K Knelles, B A Hersbach, D Petrik, T Riedemann, V Bednarova, A Janjic, T Simon-Ebert, W Enard, P Smialowski, M Götz, G Masserdotti

Date Published: 20th Jul 2021

Publication Type: Journal

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