Andreas Hermann Group
How human neurons get sick: Disease modeling of neurodegenerative diseases using hIPSCs
Our initial studies were on characterization of different adult neural stem cell types from murine and human brain and human bone marrow. Special impetus was put on the regenerative capacity of the adult midbrain. We systematically characterized these populations trying to study their potential use in vivo. We then moved on characterizing induced systems including induced pluripotent stem cells and induced neural stem cells and their potential for future therapeutical use.
For three years now we have been working on human cell models of rare neurodegenerative diseases with special emphasis on neuroacanthocytosis, neuronal ceroid lipofuscinosis as well as motor neuron degeneration (using iPS cells). The overall goal is to use hiPSCs as model cells for studies on the molecular pathophysiology of rare neurodegenerative diseases. We thereby want to understand the underlying mechanisms to develop new therapeutic targets (including new concepts of targets).
We have many fully characterized hIPSCs in hand which show clear sings of neuropathology (see publications). We additionally established differentiation protocols for all neuronal cell types of interest. This enables us now to in depth analyse pathophysiological changes. We have isogenic lines and hiPSCs with tagged endogenous proteins in hand.
Overall goal: The overall goal is to understand the interaction of cell organelles, neuronal excitability and the cytoskeleton in inducing neurodegenerative events. This is of great importance since the overall question in neurodegenerative diseases is about the initial event, the diagnosis and treatment in stages prior to induction of an irreversible change.
Experimental approach: To use patient-specific induce pluripotent cell models from a (i) storage disease (NCL), (ii) aggregate prone disease (ALS) and (iii) a disease with no aggregates but hyperexcitability (ChAc) combined with state of the art live cell imaging techniques, electrophysiology and biophysical tools (PIV, laser ablation for cortex tension measurements, AFM). We will differentially characterize organelle structure and motility, excitability, cell and axonal growth and cell cortical plasticity in the different diseases. Subsequently, we will interfere with each part of the trinity and measure the consequence on the two other domains to finally understand their interactions.
Significance: The results will contribute to the understanding of the interaction of cellular structure, cellular organelle and cellular function and how this lead to neurodegeneration to provide novel drug targets for causative therapies.
Future Projects and Goals
Aim 1: Differentially analysing cell organelle, neuron excitability and cytoskeleton in three paradigmatic neurodegenerative diseases
Aim 2: Exploring the interaction of cell organelle, neuron excitability and cytoskeleton on inducing neurodegenerative events (trinity of neurodegenerative diseases)
Aim 3: We are specifically interested how defects of nuclear proteins cause axonal phenotypes using live cell imaging techniques, inhibitor studies, laser irradiation, -omics approaches.
Methodological and Technical Expertise
- human induced pluripotent stem cells (hiPSC)
- neuronal differentiation
- live cell imaging
- tagging of endogenous proteins
- disease modeling and drug discovery