David Pincus, PhD, Assistant Professor of Molecular Genetics and Cell Biology and Asif Ali, PhD, Postdoctoral Researcher
Researchers from the University of Chicago are utilizing advanced imaging techniques to obtain unprecedented data on cells and their reaction to heat stress. These findings provide valuable data on cell heat stress response and recovery.
In the study, published in Nature Cell Biology, the researchers combined numerous imaging techniques to show how cells employ a protective mechanism to safeguard their ribosomal proteins when exposed to heat shock. To protect these proteins, cells preserve them with a liquid-like condensate. Once the cell is no longer experiencing heat shock, the condensate disperses, facilitating the maturation of the orphaned proteins. The data also demonstrates that cells unable to maintain the liquid state of the condensate recover at a much slower rate, oftentimes lagging by 10 generations.
"Asif developed an entirely new cell biological technique that lets us visualize orphaned ribosomal proteins in cells in real time, for the first time," said David Pincus, Assistant Professor of Molecular Genetics and Cell Biology at UChicago. "Like many innovations, it took a technological breakthrough to enable us to see a whole new biology that was invisible to us before but has always been going on in cells that we've been studying for years."
The researchers utilized lattice light sheet 4D imaging as well as pulse labeling utilizing “HaloTag” to create fully dimensional images of the orphaned proteins within the liquid droplets of material near the nucleolus. "I think a very plausible general definition for cellular health and disease is if things are liquid and moving around, you are in a healthy state, once things start to clog up and form these aggregates, that's pathology," Pincus said. "We really think we're uncovering the fundamental mechanisms that might be clinically relevant, or at least, at the mechanistic heart of so many human diseases."
The team plans to continue their research and employ electron microscopy to capture images at an atomic level of the interior of frozen cells. Pincus believes they will find an organizational system that allows cells to recover after heat shock subsides. "I have to believe they're not just jumbled up and mixed together," Pincus said. "What we're hoping to see within what looks like a disorganized jumbled soup, there's going to be some structure and order that helps them start regrowing so quickly."