Claudia Ntsapi

By Claudia Ntsapi, Chrisna Swart, Dumisile Lumkwana and Ben Loos

Protein degradation through autophagy is one of the key pathways that maintain proteostasis and neuronal viability. Dysregulation in autophagy has been associated with a number of major protein aggregation storage disorders that are characterized by increased cellular vulnerability and susceptibility to undergo cell death. Although the molecular machinery, the proteome, and the regulation of the autophagy system are becoming increasingly clear, the specific nature of its dysfunction in the context of neuronal disease pathogenesis remains largely unclear. Moreover, although the intricate network of autophagy regulatory proteins with key metabolic checkpoints is increasingly being revealed, the relationship between autophagy dysfunction, the changing rate of protein degradation in the specific pathology, and the aggregate prone behavior of specific candidate proteins remains less understood. Many questions remain and deserve urgent attention. When does a neuron respond with heightened autophagic activity and When does the system fail to degrade autophagy cargo? This book chapter will focus on some of the main challenges in the field of autophagy research, the identity, and nature of autophagic flux failure in neurodegeneration, current means to discern and measure autophagic flux dysfunction in neuronal tissue, and recent advances in compensating the flux offset. Specifically, the role of both macroautophagy and chaperone‐mediated autophagy in neuronal function and dysfunction and the spatiotemporal changes in their rates of protein degradation will be discussed and their molecular interplay highlighted. Finally, current advances in the use of autophagy modulators to better control autophagy activity will be stressed and contextualized within the framework of re‐establishing neuronal proteostasis to favorably control cellular fate.

Part of the book: Autophagy in Current Trends in Cellular Physiology and Pathology

By Claudia Ntsapi, Andre du Toit and Ben Loos

Autophagy is the major intracellular system which is critical for the removal of harmful protein aggregates and malfunctioning organelles. Dysfunctional autophagy is associated with a multitude of human diseases, such as protein aggregation in Alzheimer’s disease and non-successful aging. Major interest exists in the dietary manipulation of the autophagy pathway activity, so as to tune the cell’s protein degradation capabilities and to prevent cell death onset. It has recently become clear that the machinery required to degrade protein cargo has a distinct activity level which can be altered through specific dietary modulation. Moreover, this activity may differ from that of the proteinaceous cargo. Overall, brain health and successful aging are characterized by limited protein aggregation, with a distinct molecular signature of maintained autophagy function. However, it is largely unclear how to control autophagy through dietary interventions with a precision that would allow to maintain minimal levels of toxic proteins, preserving neuronal cell viability and proteostasis. In this chapter, we carefully dissect the relationship between autophagy-modulating drugs, including caloric restriction mimetics and their impact on neuronal autophagy, in the context of preserving brain health.

Part of the book: Feed Your Mind