Connectome-based models of neurodegenerative disease
Neurodegenerative diseases involve accumulation of aberrant proteins in the brain, leading to brain damage and progressive cognitive and behavioral dysfunction. Many gaps exist in our understanding of how these diseases initiate and how they progress through the brain. However, evidence has accumulated supporting the hypothesis that aberrant proteins can be transported using the brain’s intrinsic network architecture — in other words, using the brain’s natural communication pathways. This theory forms the basis of connectome-based computational models, which combine real human data and theoretical disease mechanisms to simulate the progression of neurodegenerative diseases through the brain. In this talk, I will first review work leading to the development of connectome-based models, and work from my lab and others that have used these models to test hypothetical modes of disease progression. Second, I will discuss the future and potential of connectome-based models to achieve clinically useful individual-level predictions, as well as to generate novel biological insights into disease progression. Along the way, I will highlight recent work by my lab and others that is already moving the needle toward these lofty goals.
Targeting selective autophagy against neurodegenerative diseases
Protein quality control is essential for maintenance of a healthy and functional proteome that can attend the multiplicity of cellular functions. Failure of the systems that contribute to protein homeostasis, the so called proteostasis networks, have been identified in the pathogenesis of multiple neurodegenerative disorders and demonstrated to contribute to disease onset and progression. We are interested in autophagy, one of the components of the proteostasis network, and in the interplay of wo selective types of autophagy, chaperone-mediated autophagy (CMA) and endosomal microautophagy (eMI), with neurodegeneration. We have recently found that pathogenic proteins involved in common neurodegenerative conditions such as tauopathies or Parkinson’s disease, can exert a toxic effect in both types of selective types of autophagy compromising their functioning. We have now used mouse models with compromised CMA that support increased propagation of proteins such as tau and alpha-synuclein and an exacerbation of disease phenotype with aging. Conversely, genetic or chemical upregulation of CMA in this context of proteotoxicity slow down disease progression by facilitating effective intracellular removal of pathogenic proteins. Our findings highlight CMA and eMI as potential novel therapeutic targets against neurodegeneration.