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Dominik Paquet – iPSC-models of brain diseases

  • iPSC derived astrocytes

    The PaquetLab aims to build human tissue models recapitulating major brain diseases. To establish these models, we apply and combine cutting-edge technologies, such as CRISPR/Cas genome editing, induced pluripotent stem cells (iPSCs), differentiation of iPSCs into human brain cells, and brain tissue engineering. Using these models, we want to understand the molecular and cellular mechanisms leading to nerve cell damage and death, and subsequent cognitive decline in patients with neuropsychiatric disorders, such as Alzheimer’s disease and frontotemporal dementia, and neurovascular impairments including stroke and vascular cognitive impairment.

    Due to the inaccessibility of human brain cells for molecular research, neurodegenerative diseases have mostly been studied in animal and simple cellular models. These have significantly broadened our knowledge, but due to their drawbacks also limit successful translational research. We address this gap by developing human disease models using a powerful combination of CRISPR genome editing – which allows altering most genes in the human genome – and iPSC technology – which allows generating and studying somatic brain cells in the laboratory that are directly affected by disease. The disease-relevant cell types we study include neurons, astrocytes, microglia, oligodendrocytes, smooth muscle cells and endothelial cells, and the research projects in our lab focus on three major areas:

    CRISPR genome editing in iPSCs

    We believe that efficient and reliable genetic access to the patient cells we study is crucial to investigate the role of disease-associated genes, genetic variations such as SNPs, and to induce or modify disease symptoms in our models. In a set of fundamental studies (Paquet et al. Nature 2016; Kwart et al. Nat Prot 2017; Kwart et al. Neuron 2019) we revealed simple principles of efficient CRISPR/Cas9 genome editing in human iPSCs. We also demonstrated the potential of studying Alzheimer’s disease-causing mutations in isogenic sets of CRISPR-edited, iPSC-derived human cortical neurons. Recent work in our lab focused on improving the reliability and specificity of the CRISPR system e.g., by revealing frequent on-target effects in human iPSCs after editing and providing the field with simple detection tools to characterize and avoid these deleterious consequences of CRISPR genome editing (Weisheit et al. Cell Reports 2020).

    Featured Publication:

    Taming widespread collateral damage of CRISPR editing

    CRISPR-Cas9 has revolutionized disease-research, as it greatly simplifies targeted genome editing. However, CRISPR systems are not entirely accurate and can introduce potentially harmful additional mutations, called on-target effects. In a collaborative study with the DichgansLab, the PaquetLab identified widespread prevalence of on-target effects in clinically relevant CRISPR-edited iPS cells and describes broadly applicable tools to detect these unintended alterations. The new method improves the reliability of CRISPR editing. [read more...]

    Brain cell differentiation from iPSCs and brain tissue engineering to study neurodegenerative diseases

    3D Tissue

    Recent work in the field has indicated that major aspects of the complex pathological processes underlying human neurodegenerative disease depend on the interplay between multiple cell types, such as neurons, microglia, astrocytes and oligodendrocytes. We therefore believe that optimal investigation of such disease processes will not only require human cells, but also complex, 3-dimensional tissue models containing the major disease-relevant cell types. In a recent review article, we discussed the current status of the field and strategies to design the next generation of iPSC-based models of brain diseases (Klimmt*, Dannert*, Paquet, Curr Opin Neurobiol 2020). A major focus of our lab is therefore to establish technologies for the optimized differentiation of all major brain cell types relevant for neurodegenerative disease, and to combine them in a 3-dimensional human brain tissue model. In this model, we aim to elicit and study disease phenotypes and investigate underlying pathomechanisms. In addition, because such models are accessible for genetic manipulation and amenable to drug development, we plan to apply them for translational studies to accelerate the identification of novel therapeutic approaches and targets. 

    Human models of brain vessels to investigate the biology of the blood-brain-barrier and mechanisms of neurovascular disease

    3D-vessel

    Increasing evidence points to a major role of brain vasculature not only in neurovascular diseases, such as stroke, small vessel disease, etc., but also in a broad group of other brain diseases including Alzheimer’s. At the same time, genetic studies from our institute and others revealed many genetic loci associated with neurovascular impairment in patients. Using the above-mentioned combination of CRISPR editing and iPSC-based tissue engineering, we are setting up modular systems of human brain vessels that allow investigating mechanisms of human neurovascular disorders and the underlying genetic causes and associations.

    Contact:

    Dominik Paquet
    Professor of Neurobiology

    Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich
    Room 8G 02 144

    Feodor-Lynen-Straße 17
    D-81377 Munich, Germany

    Phone: +49 89 4400 46123
    E-Mail: dominik.paquet@med.uni-muenchen.de

Dominik Paquet

Dominik Paquet
Professor of Neurobiology
+49 89 4400 46123
dominik.paquet@med.uni-muenchen.de