Biology of Astrocytes Group

PRINCIPAL INVESTIGATOR Michał Ślęzak, Ph.D.

The focus of our team is to understand the function of astrocyte-specific pathways in the brain physiology and pathology, particularly those mediating neurobiological phenotypes related to psychiatric disorders. In current projects, we combine state-of-the art genetic manipulation with live imaging of biological processes in relevant cellular and animal models to identify novel therapeutic strategies.

Michał Ślęzak, Ph.D., Principal Investigator

Michał graduated from the Université Louis Pasteur in Strasbourg, from the lab of Dr. Frank W. Pfrieger,  where he developed a set of novel transgenic mice for astrocyte-specific, inducible gene ablation. Afterwards, he joined Inst. Pharmacology, PAS, in Kraków, where he obtained Young Investigator Award from Polish Ministry of Science and Higher Education. During his stay, he found that astrocytes are an important cellular target in the brain of systemic glucocorticoids. He accomplished his postdoctoral training during Marie Curie IEF fellowship at VIB, KU Leuven. At this time, he obtained the direct evidence for the functional sensory tripartite synapse using in vivo imaging. Simultaneously, he developed a novel methods for flexible genetic manipulation of astrocytes in wild-types animals. His first independent position was at BioMed X in Heidelberg, where he led a project sponsored by Boehringer Ingelheim. Within four years the team has obtained the comprehensive evidence supporting the dysfunction of astrocytes in depression. The project resulted in a new drug discovery program launched by the sponsor.

Kamila Mizerska, Ph.D.

Kamila graduated from the Institute of Neuroscience, CSIC-UMH in Alicante, under the supervision of Dr. Juana Gallar. She did her postdoctoral training at Weill Cornell Medicine in New York conducting research in the area of Ocular Neurobiology. She investigated the effects of Dry Eye Disease, epithelial wound healing and aging on corneal nerves activity and morphology. She has the experience in consulting and contract research organization providing scientific support to pharmaceutical companies in Market Access and Medical Affairs departments.

Barbara Górka, M.Sc.

Barbara obtained her MSc degree in Molecular Biotechnology at the University of Warsaw, under the supervision of Dr. Magdalena Dziembowska. She gained experience mainly in the field of neurobiology and genetics. As a part of the Erasmus+ program, she spent a few months in The Cyprus Institute of Neurology & Genetics conducting research in genetics of premature puberty.

Marcin Knut, Ph.D.

Marcin accomplished his education at University of Glasgow with merits and graduated from the University of Southampton, supervised by Dr. William Tapper. He developed pipelines for the analysis of cancer transcriptomes and discovered novel gene fusions in myeloid neoplasms. He has experience in teaching and small business. His passion are motorcycles, swimming and violin music.

Agnieszka Krzyżosiak, Ph.D.

Agnieszka accomplished her PhD under the supervision of Dr. Wojciech Krężel and Prof. Piotr Dobryszycki, through co-tutelle between Université de Strasbourg and Wrocław University of Technology. Working at the Institut de Génétique et de Biologie Moléculaire et Cellulaire, she discovered the role of RXRg in mediating depressive-like behaviors and underlying molecular dysfunction of dopaminergic neurons. For her postdoc, Agnieszka joined the team of Dr. Anne Bertolotti at the MRC Laboratory of Molecular Biology, Cambridge, UK where she was awarded an EMBO and HFSP long-term fellowship. In her research, she investigated the strategies to prevent protein misfolding in neurodegenerative disorders. This work revealed the first selective inhibitor of PPP1R15B phosphatase with beneficial effect in ameliorating the symptoms of Huntington’s disease. The discovery led to establishing a startup CamPhos Therapeutics Ltd., where Agnieszka gained an invaluable experience in commercializing the outcome of basic research.

Astrocytes are known for their diverse and essential functions, including neurotransmitters recycling, regulation of synaptic transmission and control over the brain metabolism. These tasks are moderated through systemic signals, including hormones. Our team found that astrocytes are a direct transcriptional target for glucocorticoids in the brain and we identified that crucial metabolic pathways in astrocytes are controlled through glucocorticoid receptor activation. Moreover, we shown that this signaling pathway is necessary for central effects of acute and chronic stress. Interestingly, multiple members of GR-dependent pathway were consistently identified as dysregulated in transcriptomic studies of brain samples from patients of diverse psychiatric diseases. In our current research we investigate the contribution of selected pathways and genes for neurobiological correlates of circuit-specific impairments related to psychiatric phenotypes.

Transgenic mouse models:

  • Spatio-temporally controlled genetic manipulations with conditional KO (Cre-ERT2/loxP)
  • Viral vector delivery
  • In utero electroporation–based method for flexible genetic manipulation in specific cell types across various species

Imaging:

  • 1-photon and 2-photon in vivo imaging of astrocyte calcium signaling in behaving mice
  • Fiber photometry with simultaneous behavior monitoring in individual mice
  • Long-term live cell imaging in vitro

Omics:

  • Optimized protocols for isolation of various cell types from mouse brain
  • Optimized protocols for isolation of astrocyte nuclei from fresh frozen human samples
  • RNAseq, nuclei RNAseq

Behavior:

  • Automated live tracking of spontaneous behavior of multiple animals
  • Rodent models of stress: chronic social defeat stress, early maternal separation stress
  • Depressive-like phenotypes: 3-chamber social interaction, dark-light box, sucrose preference
  • Cognitive tests: Y-maze, elevated plus maze
  • Circadian activity: running-wheel cages

Cell culture:

  • Human iPSC-derived cultures of astrocytes and astrocyte-neuron co-cultures
  • Primary mouse astrocyte and neuronal cultures

Metabolic readouts:

  • Seahorse (glycolysis rate; oxygen consumption; fuel usage)
  • Mitochondrial membrane potential (TMRE)
  • Live cell imaging – based measure of glycolytic rate
  • Long-term imaging of genetically encoded metabolic indicators in vitro and in vivo

Molecular genetics:

  • Standard cloning, Gateway, Gibson assembly, Golden Gate assembly
  • Bacterial artificial chromosomes
  • Viral vectors
  • CRISPR/Cas9 gene editing
  • shRNA, siRNA – based gene silencing

Standard readouts:

  • Immunocytochemistry
  • Immunohistochemistry
  • Western blot, Southern blot
  • Golgi staining
  • ELISA
  • RNAscope

Tripartite synapse:

  1. Slezak M*, Kandler S*, Van Veldhoven P, Bonin V, Holt MG. Distinct mechanisms for visual and motor related astrocyte responses in mouse visual cortex. (2019) Curr Biol. 29 (1-8).
  2. Slezak M*, Grosche A*, Niemiec A*, Tanimoto A, Pannicke T, Münch TA, Crocker B, Isope P, Hartig W, Beck SC, Huber G, Ferracci G, Perraut M, Reber M, Miehe M, Demais V, Lévêque C, Metzger D, Szklarczyk K, Przewłocki R, Seeliger MW, Sage-Ciocca D, Hirrlinger J, Reichenbach A, Reibel S, Pfrieger FW. (2012) Relevance of exocytotic glutamate release from retinal gliaNeuron. 74: 504-16
  3. Kremer A, Lippens S, Bartunkova S, Asselbergh B, Blanpain C, Fendrych M, Goossens A, Holt M, Janssens S, Krols M, Larsimont JC, Mc Guire C, Nowack MK, Saelens X, Schertel A, Schepens B, Slezak M, Timmerman V, Theunis C, Van Brempt R, Visser Y, Guérin CI. (2015) Developing 3D SEM in a broad biological context. J Microsc. 259:80-96.
  4. Slezak M, Pfrieger FW & Sołtys Z. (2006) Synaptic plasticity, astrocytes, and morphological homeostasisPhysiol. (Paris). 99:84-91
  5. Slezak M. & Pfrieger FW (2003) Role of astrocytes in synaptogenesisTrends in Neurosci. 26: 531-535.

Glucocorticoid signaling in astrocytes:

  1. Tertil M*, Skupio U*, Barut J, Dubovyk V, Wawrzczak-Bargiela A, Soltys Z, Golda S, Kudla L, Wiktorowska L, Szklarczyk K, Korostynski M, Przewlocki R, Slezak MGlucocorticoid receptor signaling in astrocytes is required for aversive memory formation. (2018) Transl Psych. 8:255.
  2. Slezak M, Korostyński M, Dzbęk J, Gieryk A, Gołda S , Piechota M, Wlazło E, Przewłocki R. (2013) Astrocytes are a target of the glucocorticoid receptor-dependent component of morphine actionGlia. 61:623-35.
  3. Piechota M, Korostyński M, Solecki W, Gieryk A, Slezak M, Bilecki W, Ziółkowska B, Kostrzewa E, Cymerman I, Świech L, Jaworski J, Przewłocki R. (2010) The dissection of transcriptional modules regulated by various drugs of abuse in the mouse striatumGenome Biol. 11: R48.

Genetic tools for astrocytes:

  1. Slezak M*, De Vin F*, Shinmyo Y, Batiuk MY, Rincon MY, Menacho Pando C, Urschitz J, Moisyadi S, Schnütgen F, Kawasaki H, Holt MG. Flexible, fast and selective genetic manipulation of the vertebrate CNS with misPiggybioRxiv (https://doi.org/10.1101/481580).
  2. Pfrieger FW & Slezak M. (2012) Genetic approaches to study glial cells in the rodent brainGlia. 60: 681-701.
  3. Slezak M, Goritz C, Niemiec A, Frisen J, Chambon P, Metzger D, Pfrieger FW. (2007) Transgenic mice for conditional gene manipulation in astroglial cellsGlia. 55: 1565-76.

IPSC-based models:

  1. Plociennikowska A, Frankish J, Moraes T, Del Prete D, Kahnt F, Acuna C, Slezak M, Binder M, Bartenschlager R. TLR3 activation by Zika virus stimulates inflammatory cytokine production which dampens the antiviral response induced by RIG-I-like receptors. (2021) J Virol. 95:e01050-20.