Caenorhabditis elegans as a model system for studying aging-associated neurodegenerative diseases

Neurodegenerative diseases (NDs) are a heterogeneous group of aging-associated disorders characterized by the disruption of cellular proteostasis machinery and the misfolding of distinct protein species to form toxic aggregates in neurons. The increasing prevalence of NDs represents a growing healthcare burden worldwide, a concern compounded by the fact that few, if any, treatments exist to target the underlying cause of these diseases. Consequently, the application of a high-throughput, physiologically relevant model system to studies dissecting the molecular mechanisms governing ND pathology is crucial for identifying novel avenues for the development of targeted therapeutics. The nematode Caenorhabditis elegans (C. elegans) has emerged as a powerful tool for the study of disease mechanisms due to its ease of genetic manipulation and swift cultivation, while providing a whole-animal system amendable to numerous molecular and biochemical techniques. To date, numerous C. elegans models have been generated for a variety of NDs, allowing for the large-scale in vivo study of protein-conformation disorders. Furthermore, the comparatively low barriers to entry in the development of transgenic worm models have facilitated the modeling of rare or "orphan" NDs, thereby providing unparalleled insight into the shared mechanisms underlying these pathologies. In this review, we summarize findings from a comprehensive collection of C. elegans neurodegenerative disease models of varying prevalence to emphasize shared mechanisms of proteotoxicity, and highlight the utility of these models in elucidating the molecular basis of ND pathologies.