Show NotesDr. Bruder began our interview by talking about the importance of using an iPS-based screening model and how this compares to other models, including animal models. He described the biggest challenge in neurodegenerative disease modeling as cell sourcing and he provides an explanation for this. Accessing diseased cells in neurodegenerative diseases means taking a portion of a patient’s brain, and not surprisingly, that is not a popular option. Another challenge is that in Parkinson’s Disease for example, dopaminergic neurons are dying and by the time one receives a diagnosis, there could be up to 80% dopaminergic neuron loss, making it very difficult to study the underlying disease mechanisms. Even if researchers are able to access a sample from the biopsy of a Parkinson’s patient, neurons are post mitotic so the cells can’t be expanded in culture. Thus, you are not able to generate enough cells to really run meaningful experiments. Lastly, he talks about how a great deal of research has demonstrated that animal models don’t best mirror human physiology or biochemistry, particularly in neurological applications. He provides examples of drugs that have dropped out of clinical trials due to either lack of efficacy or toxicity. This is where the iPS cells provide such a great option as they circumvent the cell sourcing issue and allow the creation of disease models to explore questions about disease initiation, progression, and potential treatment. He then went on to describe his group’s work on Parkinson’s Disease and creating an automated system for creating dopaminergic neurons and large compound screens against the disease. The first step for them was to generate an iPS line from patients that carry a gene mutation, which predisposes them to the disease. However, iPS cells are not really suitable as a starting point for an automated system as they require expensive growth factors and manual monitoring. It is possible, but not ideal. So, they developed a precursor cell type that is very proliferative and easy to maintain. Using these precursor cells, they can generate dopaminergic neurons in only two weeks. To automate the system they take the precursor cells that are in manual culture and transfer them to automated culture by moving them to their liquid handling system, the Beckman Coulter Biomek FXP automation workstation. Over the course of two weeks they add differentiation factors then direct the cells to develop into dopaminergic neurons that carry a Parkinson’s disease mutation. However, they were surprised initially to find that generated neurons were healthy looking, when they expected them to be diseased. Yet, this made sense after some thought because Parkinson’s Disease does not affect people until they are 50-60 years old. So in order to make a functional disease model, they needed to artificially age the neurons. Dr. Bruder then discussed the advantages of moving this type of work to automation. He stated three primary advantages:
- It allowed them to scale up the number of compounds they could test by a factor of 100.
- It reduced the cost because they could run using 384-well plates.
- It reduced the experimental error by standardizing the operation.