Neurodegenerative diseases, like Alzheimer’s, Parkinson’s, and motor neuron diseases such as Amyotrophic Lateral Sclerosis (ALS) and spinal muscular atrophy, have a profound impact on patients and their families. Developing effective treatments for these conditions is faster when we have access to translational models that help identify promising drug candidates for clinical trials. This article provides an overview of how complex cell models contribute to neurodegenerative disease research, along with advanced live-cell techniques that offer valuable insights.
The Importance of Complex Cell Models in Disease Research
Traditional disease models have often used immortalized cell lines, like HeLa and HEK293 cells, and primary cells from animal or human tissues. While these models have led to many scientific breakthroughs, they don’t fully capture the complexity of human diseases.
Complex cell models, such as induced pluripotent stem cells (iPSCs) and Three-dimensional (3D) cultures, represent a significant shift in disease modeling1. iPSCs can turn into any cell type, offering a renewable source of patient-specific cells that keep the donor’s genetic information. This allows for modeling diseases with a genetic component in a personalized way, providing insights into how diseases progress and respond to treatment. iPSCs also make it possible to study rare diseases where patient samples are hard to find, expanding research and potential treatments.
3D cell models, like organoids and spheroids, enhance iPSCs by creating tissue-like structures. These models mimic the architecture and complexity of organs, including gradients for oxygen, nutrients, and signaling molecules, which are crucial for understanding disease progression and treatment effectiveness.
Predictive Cellular Models for Neurodegenerative Diseases
Using iPSCs in neurodegenerative disease modeling allows for a more accurate study of disease mechanisms. iPSC-derived neurons can show key Alzheimer’s features, like amyloid-beta peptide aggregation and tau hyperphosphorylation, providing a dynamic system for studying disease progression. Additionally, iPSCs help study neuronal loss and synaptic dysfunction, which are crucial for understanding neurodegeneration.
Beyond modeling disease pathology, iPSCs are transforming drug discovery and development. iPSC-derived neural cells allow for high-throughput screening to identify potential therapeutics and assess drug toxicity and efficacy, speeding up the transition from lab research to clinical application.
Stem cell-derived 3D cell culture techniques have greatly improved our ability to model neurodegenerative diseases2,3. For Alzheimer’s, 3D brain organoids allow us to observe amyloid plaque formation and neurofibrillary tangles, providing a more accurate platform for investigating disease mechanisms and evaluating drug candidates. These 3D models also enhance the study of non-neuronal factors in neurodegeneration, like microglial involvement in inflammation and the influence of astrocytes on neuronal health4.
Pros and Cons of Traditional Cell Analysis Techniques
Traditional cell biology techniques like flow cytometry and high-content imaging have been invaluable to the field. However, these methods have limitations in certain applications with complex cell models.
3D cultures require more attention than traditional 2D cultures because of their complex structure and organization. Regular monitoring ensures that they develop and maintain the right morphology throughput development. As these multicellular clusters grow, they become more opaque, making it harder to visualize without special techniques.
Maintaining physiological relevance is also crucial, underscoring the importance of non-invasive options. The preparation and labeling required for some methods can alter the cellular environment, potentially skewing the data. Moreover, conventional techniques usually provide snapshots at single time points, missing the dynamic cellular changes.
Real-time solutions that address these gaps will ultimately help us unlock the full potential of these disease models.
Real-Time Monitoring of Live Cellular Behavior
Live-cell analysis overcomes many of these limitations through continuous monitoring of living cells without disrupting their natural state. For example, live-cell analysis can observe the growth and maturation of iPSC-derived neurons or the development of neural networks in 3D brain organoids.
Platform technologies like Incucyte® Live-Cell Analysis (Sartorius) combine these capabilities with true throughput, addressing a major gap in industry workflows. Its non-invasive approach permits the detection of gradual cellular changes in morphology, function, and interactions, crucial for studying diseases with slow cellular progression. Additionally, the system’s ability to simultaneously monitor multiple parameters, such as cell morphology and marker expression, is invaluable for understanding complex cellular behaviors like phagocytosis.
Numerous studies have shown the value of live-cell analysis in neuroscience research, including one by the Tilman group at Axol Bioscience Ltd. demonstrating disease-specific functional impairments in ALS cells5. Their work revealed morphological and functional differences between healthy and iPSC-derived ALS cells, with ALS motor neurons showing disorganized structures and erratic firing patterns, and ALS microglia demonstrating reduced phagocytosis. They used the Incucyte® system to measure spontaneous neuronal activity and microglial phagocytosis, highlighting the value of a streamlined process for real-time monitoring of cellular behavior.
Conclusion
The integration of advanced cell models with live-cell analysis is a critical development in neurodegenerative disease research. This non-destructive approach allows for the continuous collection of vital data, enhancing our understanding of disease mechanisms and treatment effects. As these techniques evolve, they will be instrumental in improving outcomes for patients.
References:
- Langhans SA. Three-dimensional in vitro cell culture models in drug discovery and drug repositioning. Front Pharmacol. 9, 6 (2018). https://doi.org/10.3389/fphar.2018.00006
- Lee HK, Velazquez Sanchez C, Chen M, Morin PJ, Wells JM, Hanlon EB, Xia W. Three-dimensional human neuro-spheroid model of Alzheimer’s disease based on differentiated induced pluripotent stem cells. PLoS ONE. 11, e0163072 (2016). https://doi.org/10.1371/journal.pone.0163072
- Park J, Wetzel I, Marriott I, Dréau D, D’Avanzo C, Kim DY, Tanzi RE, Cho H. A 3D human triculture system modeling neurodegeneration and neuroinflammation in Alzheimer’s disease. Nat Neurosci. 21, 941–951 (2018). https://doi.org/10.1038/s41593-018-0175-4
- Park J, Wetzel I, Marriott I, Dréau D, D’Avanzo C, Kim DY, Tanzi RE, Cho H. A 3D human triculture system modeling neurodegeneration and neuroinflammation in Alzheimer’s disease. Nat Neurosci. 21, 941–951 (2018). https://doi.org/10.1038/s41593-018-0175-4
- Tilman J. iPSC-derived motor neurons and microglia from ALS background display disease phenotype. Axol Bioscience Ltd. (2023, August 31). Available from: https://www.sartorius.com/en/products/live-cell-imaging-analysis/live-cell-analysis-resources/ipsc-derived-motor-neurons-and-microglia-white-paper
