The metabolic regulation of anchor cell invasion through basement membrane in C. elegans

Basement membranes (BM) are dense, highly crosslinked sheets of extracellular matrix proteins that surround and constrain cells in animal tissues. Specialized cells acquire the ability to invade through BM barriers during development and homeostasis, and aberrant BM invasion underlies many diseases. Invading cells use transient and specialized cellular protrusions to breach the BM, and the membrane dynamics and cytoskeletal rearrangements necessary to build and fuel these structures are both energy intensive and metabolically complex. Thus, it is crucial to understand how invasive cells regulate their catabolic and anabolic metabolism to drive BM invasion, but experimentally dissecting stochastic cell invasion events that occur deep within optically inaccessible tissues in vivo is challenging. Here I use the C. elegans anchor cell (AC) as an experimentally tractable and visually accessible in vivo model for cell invasion through the BM, and use 4D live cell imaging , metabolic biosensors, and RNAi-mediated screening to investigate how invading cells regulate their ATP production and lipid metabolism to drive invasion through the BM. In Chapter 1, I review the mechanisms used by cells to fuel invasion through matrix and identify gaps in our understanding of localized energy production during invasion. In Chapter 2, I discover that localized glucose import, and glycolytic processing support rapid and transient ATP production by mitochondria in the AC to fuel the invasive protrusions for BM invasion. In Chapter 3, I identify that sphingolipid biogenesis and protein prenylation support the formation of the invasive protrusion and the actin-based invasion machinery within in to breach the BM barrier. In Chapter 4, I discuss the implications of these findings on our understanding of the metabolism of cells invading through the BM.